All About Batteries
Hey. Welcome to the episodes 24 of TechEdv24. This time available as a motion picture. Today we are talking about batteries. How do they work?
Speaker 1:You know, the pack voltage. Will we ever see them charging in minutes? All that good stuff. So sit back and relax, and, watch the episode. Listen to the interview.
Speaker 1:We've got an interview with Ewan MacTac. It's been requested by so many people. We finally found the time, to sit down and and talk about it. Sadly, not in person, but, you know, hopefully, this is gonna be enjoyable. And it's gonna be available on YouTube as well if you're listening to this as an audio.
Speaker 1:Apologies in advance for the quality of the recording. It was a Skype conversation, and I couldn't use this setup to, to record it, sadly. But, nonetheless, the format and the questions, you know, it's all worth it. So
Speaker 2:So, yeah, thanks for for having us on. I'm doctor Ewan McTurk, and I'm a consultant battery electric chemist who's been working with and driving electric vehicles for just over a decade now. I'm also the creator of the YouTube series PlugLife Television, which explains complex battery electric industry in a way that anyone can understand and also demonstrates how the entire nations can can decarbonize their transport, not just, cars, but looking at all the other forms of transport too. And that also busts many myths around the battery tech along the way. Cool.
Speaker 1:So should I refer to you as, doctor Ewan or just is Ewan
Speaker 2:I'll just go with Ewan.
Speaker 1:I yeah. I know I know it takes a very long time to actually get, you know, the doctor in front of your name, so some people prefer others, you know. Let's let's go with the casual then. So I've I've got loads of smart and, you know, listeners. I don't wanna, take away from them, but, obviously, it would be nice to just have, like, a basic, understanding of what is a battery and why do we need them and what's so great about them.
Speaker 2:Yeah. So a battery is an electrochemical means of storing energy, of of storing electricity. It's a very efficient way of of storing energy as well. If you look at the likes of a round trip efficiency of a of a lithium ion battery in terms of energy in versus energy out, it's typically about 85% efficient, if not more. So, you know, you compare that to other technologies.
Speaker 2:You know, you compare that to the the low tens of percent efficiency of an internal combustion engine or sort of 50 to 60% efficiency of a fuel cell, is certainly a very efficient way of storing energy. Admittedly, in terms of the capacity that can be installed, it can be stored per per kilo per kilogram, you know, gravimetric energy density or per liter volumetric energy density. That's where batteries have generally fallen down over the years. But we're now seeing with the last decade or so of developments in particular with electric vehicle batteries with lithium ion, that, you know, that's genuinely not becoming an issue anymore. You know, you've you've got sort of budget esque, vehicles like the Renos away, like the MG, the MG 5 that can do, you know, close on 200, if not more, 200 than 200 miles per charge.
Speaker 2:And, you know, their their costs are broadly comparable with an equivalent internal combustion engine vehicle. So, you know, given that most people need to stop before 200 miles of continuous driving, otherwise, they can't feel their legs, You know, that's that's easily enough range. So batteries are are definitely at a stage now where we're we're we're seeing a mass takeoff on on electric vehicle uptake, because we've kind of reached that sweet spot. But lithium ion batteries are nowhere near done yet. And there's all sorts of exciting chemistries we'll get on to later on as well, no doubt, in this chat.
Speaker 2:So batteries are they've finally caught up with, with road transport and other transport, you know, means as well, having been a fantastic starting point for horseless carriages, you know, at the end of the Victorian era. But that was when roads were particularly rubbish and top speeds were very low. Actually, lead acid batteries back then could give you about a 100 miles per charge because you didn't need much power because the top speed was only gonna be 5 or 6 miles or, you know, 5 or 6 miles per hour. Yeah. Of course, when roads improved and top speeds improved, the power required to sustain those top speeds got higher, and that's when lead acid just couldn't cope with it.
Speaker 2:But lithium ion, we're now at that stage where we we can we can actually provide that amount of energy and the amount of power that's required to sustain a a a modern vehicle to the the standards that we would expect.
Speaker 1:Okay. And, obviously, like, just in terms of the the battery, like, the basics, it literally just stores electrons. Right? That's the that's like the very low level electron transfer.
Speaker 2:It it stores in in means of a of of a chemical reaction. And depending on the chemistry, you know, there there are so many different chemistries out there. A lead acid battery is a completely different beast to a lithium ion battery, for example. And if anything, lithium ion batteries are probably one of the most different chemistries to any of the kind of predecessors within the automotive world. If you look at lead acid, if you look at nickel cadmium, nickel methyl hydride, lithium ion is very different because the only thing that takes part in the reaction really is is lithium atoms, which when the battery is fully charged, all the lithium atoms are intercalated or or pigeonholed into, sheets of of of graphene that make up the graphite within the negative electrode.
Speaker 2:So they they fit in between those layers of graphene in little pigeon holes.
Speaker 1:Okay.
Speaker 2:And, you know, they're they're all there. And when it comes to discharging the battery, what happens is that the lithium atoms each lose an electron and become a positively charged lithium ion that is able to travel through the cell, through the the separator and the electrolyte, the conductive ionically conductive liquid, has a lithium based salt in it that allows lithium ions to travel between the 2 electrodes. And that then pigeonholes into a lithium metal oxide structure in the the positive electrodes. But the electron can't go through the cell, through the inside of the cell. It needs to find another way to go and recombine with that lithium, you know, with that lithium ion.
Speaker 2:So it has to take the external circuit, which is whatever you've plugged to that battery into, in this case, an electric vehicle.
Speaker 1:Yeah.
Speaker 2:Well, that course. Yeah.
Speaker 1:That makes it power to, you know, whatever you plugged into it. That's that's that's a much better explanation than I would you could, you know, come up with. But then that's why you're the expert. The, so so so far in in sort of electric cars, you know, that we see on the market today and for the past, I don't know, about 10 years, the battery packs have been 400 volt based. But we we we've seen recently an increase or or some audience, started, testing, 800 volt, and Porsche Taycan is already 800 volt based system.
Speaker 1:I think all one of the LDs is as well, if I'm not mistaken. E tron, is it? Or, I
Speaker 2:think the E tron might actually be limited to 400.
Speaker 1:That is okay. But I
Speaker 2:could be wrong. But I'm sure that they'll have an 8 volt, sorry, 8 volt 800 volt, considerably more impressive system system on the way. Yeah.
Speaker 1:Do you think that, you know, never mind the the the battery chemistry. But, from from your perspective, do you think that, that's gonna go further? So are we gonna see 1200 volts, you know, 3000 volts batteries packs in the future?
Speaker 2:I I think that 800 volts is a pretty good trade off because it's already something you do not want to drop a spanner across the top of. It's not something you accidentally wanna touch both of those terminals. Realistically, if you're going above now this depends on which engineer you talk to, but sort of 48 volts to 72 volts. You go above that, and you wanna really start wearing big thick rubber gloves. You know, the proper, the PPE, the personal protective equipment that's rated for high voltage.
Speaker 2:Because whereas AC electricity will blow you away from it, so you touch it and it blows you clear of it. DC, which is what you get in the battery, will stick you to it. So, you know, the only way that you're getting off of that is if someone pulls you off of it with a hook, an insulating hook, or once the battery is depleted. So, you know, you definitely want to avoid going anywhere near high voltage systems if you if you can avoid if you can avoid it. Obviously, within an electric car, you're never going to come into contact with that.
Speaker 1:And
Speaker 2:you know there's there's so much safety mechanisms built into an EV, that even when it comes to dropping out that battery pack, they've got, like, midpoint isolators, which will section the battery pack into lower voltage sections, lower voltage, not not necessarily down to module level, but, you know, certainly make it a much more bite sized kind of voltage for a mechanic to handle or an engineer to to handle. Yeah. 800 volts is particularly good because that means that, you can use less current to achieve a higher power. Power is current times voltage. We're already seeing the limitations of 400 volt packs with today's high power charging infrastructure because, you look at quite a lot of our high power chargers that are out there at the moment the likes of the the InstaVault systems and some of the ones that Osprey are starting to use, motor fuel group as well.
Speaker 2:There are kind of 125 to a 150 kilowatts. And, those are you know, that's very much an up to figure. It's not necessarily it will definitely charge your car at that. Obviously, if you have, like, an older Nissan LEAF that tops out at 50 kilowatts, you're not gonna get higher than that. But if you have something like, I think the Audi e tron says that it'll do a 150, a 155 kilowatts.
Speaker 2:If you were to plug into one of these rapid chargers, high power chargers that says it will do up to a 125 up to a 150 kilowatts, then power is limited to the maximum current that the cable on that rapid charger or high power charger can provide and the voltage of the battery pack. Now bearing in mind that it's a 400 volt battery. And bearing in mind that the vast majority of these high power chargers top out at 250 amps on CCS. That means you're limited to 400 times 250, which is a 100 kilowatts. Mhmm.
Speaker 2:So, you know, your e tron driver is gonna be like, this isn't charging my car as fast as it could. Actually, yeah, this is just the the limits of it. That's the absolute maximum. Then, you know, you you unplug and a Porsche Taycan comes along that has an 800 volt battery pack. It will draw that full 125, 150 kilowatts.
Speaker 2:No bother.
Speaker 1:Yeah.
Speaker 2:So that's part of the appeal. That's why we've got the Hyundai Ioniq 5 has an 800 volt pack architecture. It seems to be the way to go because it means you can get away with using thinner lighter cables that need less cooling as well because there's less current going through them. Because, you know, if you have a 400 volt system that will do greater than a 150 kilowatts, you're really starting to look into cooling these big heavy cables. And, you know, it starts to get to the realms of needing reasonable upper body strength.
Speaker 2:Yeah. Yeah. And plus, you know, there's the, there's the the issue of what happens if the cooling system kind of corrodes through to the electrical system. And all of us, I believe, there have been some teething problems with some of those charger types. 800 volt basically resolves that issue.
Speaker 2:To go any higher than that would you know, to 1200 volt to 3000 volt as you suggested. To be honest, for road based applications, I doubt that we would need to go to that. Because, you know, if you look at the CCS standard, it can do up to 350 kilowatts. The Porsche Taycan can recharge itself in in almost no time at 270 kilowatts. But do we really need cars to charge faster than this?
Speaker 2:Because the Taycan and the Tesla models 3 and, you know, various modern EVs can rapid charge within the average dwell time at a UK motorway service station. They are adding 100 of miles in under 25 minutes. And, in fact, when the latest version, the v three supercharger, 250 kilowatts, was unveiled in the US. Now bearing in mind that the US is where people are used to doing stupidly high mileage like mega road trips in Europe were a bit more, a bit more limited in our in what we would consider an acceptable mileage. Indeed.
Speaker 2:Tesla model 3 drivers actually complained in a good way about the V3 superchargers because their car was fully charged before they'd had a whiz and a sandwich. So, you know, genuinely, the the convenience of an EV, part of the convenience is that rapid charging, it doesn't need to be 5 minutes because a petrol car, you have to go out of your way to the petrol station. That includes at the motorway service station. You've stopped. You've gone for a whiz and a sandwich.
Speaker 2:You now need to join the queue for that petrol station, fill up with the petrol, go into the shop and pay by card, blah blah blah. But with a Tesla or or an Ioniq 5 or a Taycan or, you know, to be honest, most modern EVs, you know, you sit on the I well, you you plug it into the iONITY charger. You plug it into the Tesla supercharger. You go into the service station, have a whiz in a sandwich and come back to a car that's pretty much fully charged. So you've just say you've spent literally seconds of your time recharging it.
Speaker 2:Although it's physically taken longer to refill than the petrol car did, in terms of your own time, you've only spent seconds, not the best part, 10 minutes. So I I I don't think there's any point in a higher voltage. I think we've probably reached peak Okay. PAC architecture. Could could go higher.
Speaker 2:Who knows? But I think 800 volts is pretty reasonable for for real world use.
Speaker 1:In in terms of, like, the the pure engineering, how do you think they're achieving that? Because, obviously, there is you know, we all we already know that there's a certain limit in terms of the, storage per cubic feet or meter. Apologies. I just unplugged myself. Yeah.
Speaker 1:The, you know, the the storage space. So, obviously, you're limited that way, and, obviously, each cell has certain voltage. How do you make sure how how do you then come from, you know, 400 volt pack in the same area, storage space, to 800 volts, what do you do? Like, do can you actually engineer or or design each individual cell to have double the the voltage?
Speaker 2:Oh, god. No.
Speaker 1:No. No. Okay.
Speaker 2:If you were to do that with a lithium ion cell, you would fry it. So, the a typical lithium ion cell that has a cobalt based chemistry, that said, there's an increasingly small amount of cobalt in lithium ion cells. But, you know, if you're looking at the the likes of NMC, nickel manganese cobalt oxide that's the most commonly found in electric vehicles or NCA nickel cobalt aluminium oxide used by a lot of Tesla's then typically the minimum cell voltage according to the manufacturer spec sheet will be between 2.53 volts. The car will probably be reluctant to take it below 3 volts regardless of what the spec sheet says. And the maximum voltage is gonna be 4.2 volts.
Speaker 2:The car will likely be reluctant to take it much above 4.15. Incidentally, the same type of cell theoretically in a smartphone or a laptop, the manufacturers would push those limits all for the sake of a few minutes extra runtime. There's really not that much extra energy to be gained, but you lose a lot of lifespan. So EVs have those kind of buffers, those state of charge or voltage buffers that just help to protect the lifespan by reducing degradation that happens at very high or very low voltage so yeah if you go above 4.2 volts in a conventional lithium ion cell then you start to degrade the electrolyte against the positive electrode, the cathode. That can lead to not only reduced performance and reduced capacity, etcetera, but you you can end up with flammable gases being created within the cell.
Speaker 2:It becomes very volatile, and that's when you can end up with gassing of, well, very, very hot gases. You can end up with fire as well. So you you don't want to be going, you know, anywhere above 4.2 volts with a lithium ion cell realistically.
Speaker 1:I see.
Speaker 2:And as long as you keep them within their safe limits, they're they're great. You have to do something really, really stupid to blow up a lithium ion cell. Trust me. I worked in the abuse chambers at WMG, University of Warwick. It's damn hard to blow these things up on purpose.
Speaker 2:You know, you have to be properly maniacal about how you treat them. Anyway, so, yeah. What you'd be doing at a pack level to achieve a 100 volts is you would not be building, you know, you're charging each cell to double the voltage. Absolutely not. What you'd be doing is the pack has a an SP configuration, a series parallel configuration.
Speaker 2:So cells in series are connected positive to negative to positive to negative and so on and that creates the series step kind of staircase to get to the right system voltage that you're after but that staircase might not be wide enough to get enough electrons up and down it because you're limited to the maximum current of an individual cell in series because that, you know, that current has to go through that one cell per step, if that makes sense.
Speaker 1:Yeah.
Speaker 2:So if you are basically trying to funnel, I'm trying to say, like, Oxford Circus tube traffic up a up a typical household staircase. That's not gonna happen. You need it to be a wider staircase. You need to connect them in parallel.
Speaker 1:You need multiple escalators or or staircases, basically. Yeah. Yeah.
Speaker 2:Exactly. So in in parallel, you know, you've got positive to positive, negative to negative. You've increased the capacity of the battery pack. So the the overall, energy that you can store within the battery pack, is equal to the voltage multiplied by the capacity in amp hours. So what you would do to switch from a 400 volt architecture to an 800 volt architecture in the same space is you would half the number of cells in parallel and double the number of cells in series.
Speaker 2:So that is the exact same number of cells. You're just connecting the bus bars differently. So say for the sake of argument that it was an 8 s 4 p pack. That's gonna be nowhere near 400 volt architecture. 400 volt.
Speaker 2:I should know this. I don't get my calculator. Let's do this properly, shall we? Yeah. That's gonna annoy me now.
Speaker 2:Yeah. So it'd be yeah. It'd be 192, isn't it? God's sake. Yeah.
Speaker 2:Yeah. 190 2. Yeah. I was I was going mad there. I was thinking, is that the maximum voltage or the nominal voltage, which is, like, half charged?
Speaker 2:Have I got it the right way around? Yes. I do. So, yeah, 96 s, 4 p would become 192 s 2 p. And that means you've got your 800 volts.
Speaker 2:You've ultimate you've ultimately got the same capacity, but it means you could charge the car, in theory, faster on a, you know, a a Okay. High power charger that says it's up to whatever many kilowatts but is limited to x number of amps.
Speaker 1:I I do wonder if the because obviously, you still you you can still rock up to a charger that's 50 kilowatts, say, and it's only gonna allow you to charge up to, say, 500 volts. So you have to be backwards compatible. And I I do wonder if if they have any ability to to change the number of SMPs, you know, around so that it's 4 100, 800 volts depending on what's required.
Speaker 2:I have heard of who who I was reading about the other day. There's definitely some manufacturers or at least one manufacturer that is looking into the switching of the architecture so it can derate to 400 volts for those kind of, situations, I suppose, and just makes it that bit easier to to work with as well, from an engineering perspective. So that is something that has been toyed with. Whether the Porsche already does that or not is a different matter or whether it's some sort of step down voltage converter that it has within the car. But, you know, the fact is that it's it's able to take a full 800 volts, whereas a a 400 volt EV could not and would be limited to, you know, obviously, to to charging it whatever the maximum current in that cable would facilitate.
Speaker 1:Okay. So I always thought that the so how how is it possible to increase the voltage of a cell, or is it, obviously, the area of the cathode and anodes that that gives you the the the amperage. Right? What changes the what changes the voltage of the cell?
Speaker 2:So the capacity of the cell, as you say, is determined by the total surface area of active material, you know, the cathode and the anode together. And so, you know, in a cylindrical cell, you've got 2 long continuous strips, one of anode and one of cathode, and they're all wound up in what's called the jelly roll. The other way of doing it is you get lots of stacks of, you know, your your anode and cathode anode and cathode and cathode. You connect them all in parallel inside the cell, and that gives you, you know, an increased capacity of cell. The way that you would increase the voltage of the cell, to be honest, with conventional lithium ion chemistry, we're not really gonna be increasing the voltage that much because you need to start looking into, you know, redox mediators and and sort of basically sort of dopants, if you wish, within the electrolyte, which help to reduce these degradation mechanisms that happen at high voltage because electrolytes at the moment are not very stable at the high high voltage in lithium ion cells that the electrolytes that we use today.
Speaker 2:There are attempts to try and stuff the voltage up towards 5 volts just to get a bit more capacity out of it. But that does require a very sturdy electrolyte that's not going to degrade. So what happens actually, with your, you know, with this electrolyte degradation, is that the potential difference of the cell or the voltage of the cell is the potential difference between the anode and the cathode. So each of these electrodes has a so called standard potential or or or has a potential, I should say, which you cannot measure in isolation. You need to measure it against something else.
Speaker 2:So that's why voltage is the potential differences. Yeah. You know, it's it's cathode minus anode. So what we do within the world of battery electrochemistry is we know the, the potential of the anode and the potential of the cathode versus lithium. We can't, you know, we can't measure that in in an actual cell.
Speaker 2:You need to put in what's called a reference electrode, you know, a lithium reference electrode, a third electrode, which would allow you to, you know, accurately measure it. But we have a rough idea of what those potentials are from the lab. And the high potential of the cathode when the cell is fully charged, because when the cell is charging, the cathode the positive electrode gets more positive gets a higher potential the negative electrode gets a more negative potential going down towards 0 volts versus lithium and at a certain threshold just above 4 volts really your your cathode potential gets to the point where this electrolyte starts to degrade so that's what's causing the issue. That's where the instability comes from. The electrolyte cannot cope with that potential.
Speaker 2:So it's it's not technically the voltage issue is the potential of the the cathode the the problem.
Speaker 1:Okay. So we're basically we're testing the limits and then we're kinda finding in reality, we need to use it within these two parameters to actually end up with something that's usable for, you know, certain amount of cycles and all that. Okay. I yeah. It's a it's a yeah.
Speaker 1:It's an interesting subject to me because the, because obviously, when you think about the, the pack that's 800 volts now versus 4 44400 volts, you know, one of the ways you would think, okay, we each cell has increased voltage, but but like you said, that's not the way this works. And I was wondering, and I needed somebody to actually explain this to me. So thank thank you. No worries. So I the question that I get asked all the time, and I'm you know, we've already, touched on that, but the, will we ever see a battery that recharges in a couple of minutes, or will will will it always be the way it is when you have the curve and you kinda, you know, you have to kinda, throw the electrons at the right speed into the battery to be safe?
Speaker 2:So in the lab, yes, we'll likely see, an increasing number of batteries that can recharge in a very short period of time. Exactly what capacity they will have, exactly what energy density they will have is a different matter. There are some academic developments that have managed to get recharging times down to 10 minutes or less. For example, this has been achieved by heating the cells up to about 60 degrees c during rapid charging. And lithium ion cells do not really like to go above 30 degrees c, to be honest.
Speaker 2:You know, that's when degradation starts to increase particularly above 40 degrees c, to be fair. You know, 30 is okay, but the the cooling system will try and keep the battery, you know, down towards about 25 if it can. You know, above 40, you're you're really gonna for for a prolonged exposure, you're gonna be degrading the cell. So 60, like, why are we doing this? You know, why is that surely that'll damage it.
Speaker 2:Turns out during rapid charging that the the trade off of the amount of degradation that takes place within a few minutes of super fast rapid charging versus the the lower internal resistance that comes from lowering the heat means that, you know, you can stuff in more energy in a quicker period of time as long as you immediately cool the battery afterwards. And, actually, Tesla does something similar to this with the superchargers because if you put in on a Tesla on the satnav that you're going to a supercharger, it preheats the battery to about 50 degrees c in anticipation. So it's warmed up in time for arrival. And then as soon as it's finished charging, it immediately chucks on the cooling system to extract that heat again as quickly as possible. So that's something that's already being done today.
Speaker 2:But then you've got the likes of the company StoreDots which has created a lithium ion battery, which can recharge in about 5 minutes. However, there's the engineering implications of that because that means you're dumping a lot of power for a long range EV or a lot of energy as well as a lot of instantaneous power in a very short period of time. And that entails a pretty sizable grid connection and a pretty sizable piece of charging infrastructure in order to do that. And that adds expense. And that's gonna be passed on to the end user.
Speaker 2:So, realistically, there will be some applications where that will be useful. But the additional cost of doing that is arguably not really justified in the real world as I mentioned, you know, previously. For the vast majority of people, that kind of 20 ish minute, maybe slightly longer refueling time or recharging time is actually perfect because that's enough time for you to stretch your legs, have a quick bite to eat, and you're that's what you were gonna do anyway after x 100 number of miles, you know, and you're back on the road again. So do we really need them to charge that fast? I would say no.
Speaker 2:And, of course, the vast majority of charging, now I'm not denying for a second that high power charging is essential because it's needed for when you're out and about, when you're undertaking these long journeys. But the vast majority of EV drivers are gonna slow charge overnight on street in a charging hub at home, you know, at fleets in a depot that's gonna be utilizing excess renewable electricity overnight when nothing else is using electricity because everyone's asleep. So, actually, that helps to balance the grid, and it's cheaper, and you wake up to a full battery in the morning. So you've literally spent seconds of time doing hours of charging. And, you know, in some cases, actually, if you're on dynamic electricity tariffs that track the wholesale price of electricity, if it's a particularly windy night, you could get paid to charge your car.
Speaker 2:So, yeah, I I do have, I do have reservations about stupidly fast, like, let's try and replicate petrol refilling time sort of things because do we really need to do that? The infrastructure is gonna be mightily expensive. High power charging, 100, 150, 350 kilowatt. Absolutely. But, you know, much beyond that for a typical passenger car or van, probably not gonna be that much of a biggie if I'm honest.
Speaker 1:Yeah. I, it's something that I hear from people who never driven an EV. Never mind, you know, they've they've they're just trying to think about the, which is which is a fair fair enough, you know, like, thinking scenario. Like, you think, I'm gonna I I have this car. I need to I'm gonna have to drive an EV in the future.
Speaker 1:How will this compare? But it's I always tell people it's like thinking, okay. Well, you know, I used to have holes in a buggy, and now I'm thinking about, a car, you know, and trying to do like for like. It's it's never that way. I was just wondering the the the question was just purely from engineering perspective.
Speaker 1:Like, you know, do you or or or or scientific perspective, I suppose. Like you said, you know, the the the sheer size of the connector would be and the cable would be just enormous. And, obviously, the cost of that, never mind. You know, it wouldn't be bendable. Like, it's just there's just so many things that people don't think about in terms of physics.
Speaker 1:But, you know, oh, yeah. There there are already batteries, in in buses and lorries and all all sorts of things that, have a massive pantograph that just drops on top of the bus and recharges us within minutes. ABB makes makes them. My my, well, I've been to Krakow, in in Poland in, in August. And just outside of the the railway station there, they've got one of those charges.
Speaker 1:The bus comes along Yeah. Yeah. Drops in and, you know, it's done. But nobody wants that for a for a little electric car, a family car, you know, for something to drop on top of it.
Speaker 2:It's just a just a rechargeable. Yeah. I mean, it's very, yeah, it's very much horses for courses. Okay. You know, the the bus idea is a really good one.
Speaker 2:I believe they may be using supercapacitors, at least in conjunction with batteries, if not exclusively supercapacitors, which do have crazy high power density. They're completely solid state so there's, you know, there's no ions moving in the structure. It's all to do with charged particles sort of things. And that means that you've you've got an incredibly long cycle life as well. You know, they can do like, a 1,000,000 plus cycles without any issues.
Speaker 2:But the energy density is comparatively very low. It's about a tenth of that of lithium ion. So I'm aware of some buses that have supercapacitors that do short hops between stops. We'll use the pantograph system to recharge enough to get to the next bus stop and then charge there again and again and again and again. Whereas you've got the likes of a company up in Dundee called Ember, which is running intercity electric coaches from Dundee to Edinburgh and back again, uncomfortably less than one charge.
Speaker 2:That's fully, you know, battery powers, electric buses. And then they're using a a 150 kilowatt charger to to recharge, at the Dundee Terminus. So, yeah, I mean, batteries are are more than capable of of doing the distance. But, yeah, for the short hop idea with the the pantographs, that's is is something else is being done in some cities, and it it seems to work quite well.
Speaker 1:I I I think they they they've got lithium, lithium iron, iron, iron, batteries that just configured to to charge at at, you know, stupendously high speed, but Mhmm. Don't quote me on that. Because the bus driver that I was trying to engage with and talk to him about it, he had no idea.
Speaker 2:So, you know I'm serious. Yeah.
Speaker 1:The, like, if we're gonna have time, I I would like to actually go back to solid state batteries because that's another question that and that's another thing that actually comes back every so often. But, I wanted to ask you first about, because this is you you we've touched on that on that again. Why do this is the question that I get all the time, and everyone gets that. It's, you know, it always says, this battery pack will charge up to 150 kilowatts, 70, whatever. And people are always interested, like, well, my wife plugged it in, and it's only charging at 20 degree 20 kilowatts, and then it jumps up to 70 for a couple of minutes and then drops off.
Speaker 1:Like, why is there a charging curve? Like, why why can't we have the battery that just, you know because when you're filling a bucket of water, say, you're you're dumping it mostly, you know, at the highest speed you can, and then you kinda just measure it towards the end. Why can't we do the same thing with the battery?
Speaker 2:So with, the initial kind of slower charging speed that you mentioned before it starts ramping up, that's probably because the battery or the charger is cold. And it's only once they've kind of warmed up that the internal resistance decreases enough for the car and the charger to say, yep. Okay. Get it all all day. And just, you know, stuff in, as much power as we can deal with.
Speaker 2:However, in a battery, you have something called overpotential. Potential. And that is the voltage jump in comparison to when the battery was resting, when the individual cells were resting with no current applied or or being stuffed into it. And then what happens when you charge it. And that means that voltage does jump up a bit.
Speaker 2:And that is related to the internal resistance of the cell. So as you are charging the battery, as you start to approach a higher state of charge, these individual cell voltages reach their maximum voltage, and they cannot exceed that or you end up with the electrolyte degradation that I mentioned previously. So the charger has no option but to throttle back the charging power that's being delivered to the vehicle to prevent the cells from exceeding their maximum voltage. So they've gone from constant current CC to constant voltage CV. So CCCV charging is a typical pattern for charging a battery or the individual cells within a battery.
Speaker 2:So that's why, for a lot of electric vehicles, the time taken to go from 0 to 80% state of charge on a rapid charger is about the same as going from 80 to a 100%. Now with that, that does vary depending on your EV. Some of them will will tape you know, taper off in a a bit more of a sort of conservative linear manner. I believe Tesla's are quite bad for that actually, whereas some of them will go full power and then just suddenly drop off a cliff. And then there's some that kind of do a stepped reduction.
Speaker 2:And that's all down to the discretion of the of the algorithm that has been employed by the battery management system for particular car. So, you know, some of them definitely go conservative to just try and eke out that bit more lifespan by not putting too much stress on the cell or cells, I should say. But, you know, for a typical car, around about 80% is when you start to see some significant charging power tapering off. To be honest, you are quicker on a cross country trek discharging down to about 20% state of charge then pulling into a, you know, a rapid charging hub and charging up to 80% and then getting on your way again, then you are waiting for the car to get to a 100% and then moving on. So you're actually you're doing 2 things.
Speaker 2:1, you're saving your own time. And 2, you're saving everyone else's time because you're freeing up that rapid charger for someone else who needs to use it to rapid charge. Because bear in mind, going from 80 to a 100% on a rapid charger, you might as well be using an adjacent type 2 destination charge point because you are wasting everyone's time.
Speaker 1:Yeah.
Speaker 2:That is a key key lesson in EV ownership, and it's something that annoyingly on free rapid chargers in particular, there's a lot of EV newbies, including some taxi drivers who, you know, who who don't do this. And it's particularly annoying because, you know, especially in an area that has limited charging infrastructure, it's important to utilize it as efficiently as possible. And you're genuinely more efficient charging to 80 ish percent. And for the vast majority of EVs, as I said, that 80 that I mentioned, that will vary depending on your car. But the vast majority of them are gonna be nearer to 80 or 90 than they will be to a 100%, that kind of taper off point.
Speaker 2:There's no point in just trying to eke that last drop, that last electron out of a rapid charger. If you really need the range, jump on to a type 2 post next to it if you can free it up for the person behind you.
Speaker 1:Yeah. So so does that mean that if someone designed a battery pack that, you know, stays within 20, 80, range and keeps it warm or at the optimal temperature for either discharge or charge, that it would have more flattened, charging curve then.
Speaker 2:Absolutely. And we've we've seen this already because, the Audi e tron has a reasonably big state of charge buffer at the top. So it will rapid charge quite, you know, quite close to full power almost all the way up to a 100% from what I've been told. Similarly, Tesla for a long time sold model s's worth I think it was the 75 kilowatt hour battery pack. But you had the option to buy that with only 60 kilowatt hours usable.
Speaker 2:And then you had to pay Tesla to unlock the rest of the capacity. And that meant that when you were supercharging, because that extra 15 kilowatt hours had been blocked out, what was a 100% on the dash was nowhere near a 100% in reality which meant that the cell voltages weren't reaching a 100% And that car would, you know, would drive it supercharged pretty much full power. Well, I'll be a very, very high power all the way up to a 100%.
Speaker 1:Speaking of of, of, you know, charging to only, say, 80%, do you do you have to charge batteries all the time to a 100% or every cell often to a 100% then? Or would that battery be because that's obviously the the the issue with it. Right? Because it never reaches that 100. Yeah.
Speaker 2:So, if you are using a a, you know, a destination charge point, like one on your driveway or one at your work or a shopping center or whatever, then for most EVs, I would recommend charging and balancing the car to a 100% about once a month or 2 just to recalibrate the battery management system. So it's it's kind of like, you know, if you're if you're never fully charging your phone or your laptop and you're never fully discharging your phone or laptop, eventually, it's kind of estimate of how much is left in the battery gets a bit off. And imagine doing that with hundreds of cells in a battery packet. You know, it starts to kind of lose its way a bit. Yeah.
Speaker 2:So, to be honest, most electric vehicles are pretty resilient in that regard. But I would say, charge imbalance, balance just means that all of the cells are gradually being topped up to the same voltage, because they will eventually stop to rise stop rising and falling as one you know, there'll be of some voltage discrepancy. So balancing it just means that they're all being brought back in line with each other as best as possible. So that means that, you know, you're keeping your battery in good nick, and you're keeping the battery management system up to date on what the latest state of play is. For day to day use, if you've got a reasonably short range EV or a very, very long commute, then just like I did with my 50 mile round trip commute in my 24 kilowatt hour LEAF, I had no problems about charging it to a 100% every day and arriving back home with about 40% left in the battery, plugging in, and then charging to a 100% again because I knew I was gonna be using that car a matter of hours after it finished charging.
Speaker 2:Yeah. However, I would not charge that car so a 100% and then leave it for a fortnight whilst I disappeared on holiday because that's when you start to get, you know, that electrolyte degradation I mentioned earlier at high potential for the cathode. And even with upper state of charge buffers, it's good practice to avoid that because there are some cars that have particularly small upper SOC buffers. The 30 kilowatt hour LEAF is notorious for this.
Speaker 1:Yeah.
Speaker 2:So the 30 kilowatt hour LEAF, a lot of low mileage owners would leave them plugged in. When as soon as they got home, they would plug it in. They would use it once a week to do a 5 mile round trip to Tesco and back, and then they would plug it back in again. And that because it was being so called shallow cycle that was never really been taken much lower than 80% state of charge and it was constantly being you know topped up all the way to a 100% and balanced. That means there's actually quite a few low mileage 30 kilowatt hour Nissan Leafs out there that have already got signs of battery degradation.
Speaker 2:They're missing some of their state of health bars. So I would strongly recommend for infrequent use or for, like, COVID lockdowns or going away on holiday, try and store the car between about 50 80% state of charge. That's kind of an optimum sweet spot. That means that you're not gonna be suffering from degradation, but you've also got sufficient juice in the battery to stop it from self discharging its way down to 0 even if you leave it for months on end. You have to have a car that has really high levels of parasitic drain from the the onboard electronics, like, set your century mode in the Tesla for that to be an issue.
Speaker 2:So yeah. But that said, you know, I I I now have a a model s as well. And for that same round trip commute, I was charging it up to 80%. And then I was only bothering to plug it in again once it got to about 30 or 20%. You know, that whole thing about shallow cycling, particularly at high levels of SOC, that's kind of how you kill a lithium ion battery.
Speaker 2:So I recommend, you know, if as I said, if it's regular use then and it's a short range and you need that range, absolutely take it to a 100% and then just plug it in once you're down below 50%. For infrequent use short runs, you know, commutes that you could do several of a week on one charge, you know, aim for about 80% and then plug in around about 20%. You know, just do the rough ballpark figures But that's kind of an optimum for for battery lifespan. That's being a health freak about it. But the shallow cycling and leaving them at 100% for weeks months on end, that is definitely more of a a stark warning.
Speaker 1:So so because I I I can hear my some of the people I know screaming at me or or asking the question, like, do you because obviously, unlike a bucket of water or or a tank of fuel, you can't just put a measuring device and kinda judge, you know, it's it's 3 quarters full or half full or whatever. With a cell, you just have the voltage and, and the temperature, and that's that's all you can guess, basically. So do you have to actually charge because some people are being told that they have to charge the full every cell phone just so that the BMS kinda knows where the when the where the extremity is. You know? Does that mean that you have to discharge it every so often then as well just to know the where the other end of it is?
Speaker 1:How does that work in your
Speaker 2:No. For, yeah, for a for a laptop or a smartphone, I would say, yeah, you know, you can do that so that it recalibrates the BMS. For an EV, I would not advocate doing that Okay. Because that would mean you would end up on a hard shoulder somewhere. So, yeah, I mean, that's the the kind of downside of it is you you will never really know the true capacity of an EV's battery because, 1, you're never gonna run it flat because unless you have been severely screwed over by several EcoTracy rapid chargers.
Speaker 2:But, the other thing is that, you've also got those upper and lower state of charge buffers, which do still have capacity within them. But the car is just not going to use that for, you know, for the sake of extending its lifespan. So, running it down, I mean, I I I generally wouldn't run my cars down below 10 sorry, 20% unless I needed the range. It's there for a reason. But, again, you know, leave that kind of 20% buffer partly for cell health care and partly to give yourself that bit of leeway just in case.
Speaker 2:Obviously, if you have a short range EV and, you know, it's like a 50 mile range on it and you got a 4th mile trip, then use it. Go for it. I don't blame you. But largely with the latest crop of EVs, those days are over. So, but that said, you know, there there will be people like me who have still got the 24 kilowatt hour leaf, and there'll be people who've got, like, the the Mitsubishi INEV, and they use them as as runabouts.
Speaker 2:And, yeah, as I say, by all means, use that range if if you need to. But, generally, between 20 80% is the kind of sweet spot to be running them. So, yeah, it to be honest, the battery management systems guess of what the capacity is and what the state of health is, you know, the the capacity today full capacity today versus capacity when it was new. It's all to do with best guess algorithms because it can't physically measure it. You would need to disconnect the battery from the EV and hook it up to some lab equipment to actually fully charge and fully discharge it to figure that one out.
Speaker 2:So, yeah, it will look at voltage. It will look at temperature. Coulombs to the voltage profile and do some best guess measurements. Some of them are more accurate than others. The leaf has a is well, I mean, it's it's just known as its dashboard is known as a gasometer for a reason.
Speaker 2:It's particularly sensitive to ambient temperature, and it's also particularly sensitive to charging speeds. For some reason, it predicts a lower state of health if you have, if you if you're using the granny cable or if your car has a 3.3 kilowatt onboard charger than if your car has a 6.6 kilowatt onboard charger or you've been rapid charging it a lot, which you you think it would be the other way around. And it technically should be the other way around. It's just that its algorithm is a bit wibbly wobbly. And on top of that, you know, that to put into perspective, the ambient temperature thing.
Speaker 2:I bought my car summer 2017, the leaf, and it had a state of health reading on leaf spy of 92%. And several about 10000 miles later, during the beast from the east February 2018, that brutally cold snap with all the snow and so on, the, state of health reading was a 102%. So, yeah, not technically possible. Yeah. And, yeah, it tell you what.
Speaker 2:I I felt quite smug about it even though I knew it was rubbish. But Interesting. Yeah. Yeah. It's it's all a pinch of salt, but there are some very clever companies out there working on advanced algorithms, trying to take what limited information we can get from the black box that is a lithium ion battery or a lithium ion cell.
Speaker 1:Okay. We're
Speaker 2:trying to, you know, greater predict its actual capacity, its actual state of health, its remaining useful life, these sort of things. Very, very bright minds working on that, but it'll take a little while before that starts to get adopted on mass in EVs.
Speaker 1:Solid state batteries. That's a that's a thing that that's a hype. That's the sort of holy grail that everyone everyone mentions. Like, oh, yeah. And, you know, we're gonna have some, not not to mention the h words, but I'm not gonna go there.
Speaker 1:The, you know, solid state batteries are supposed to be the holy grail of EVs, and we're supposed to be able to reach out within minutes and have 700 mile, range cars, and it's all gonna be epic, basically. What is your take on on on solid state batteries?
Speaker 2:So, yeah, solid state is a it's an interesting one. You know, you're removing the separator and the liquid electrolyte and replacing that with an all in one separator slash solid electrolyte. There are 2 different types of solid state electrolyte kind of families if you wish. The first one is ceramic, which allows fast charging times but is quite brittle. Not ideal for automotive applications if it breaks apart.
Speaker 2:The other one is polymer based. And that is flexible, but its ionic conductivity for lithium is quite low. So the charging times are slower. And, in fact, Mercedes are already offering that kind of a crude polymer solid state battery in their electric buses now. But that is with the trade off of increased range versus the lithium ion model, but with slower charging times versus the lithium ion model.
Speaker 2:So they've they've kind of accepted the limitations of the chemistry today, but gone, yeah, some people will use that. Some people will want it. So good on them for taking the plunge. There are attempts being made to do well, some quite successfully in the lab, actually, to do hybrid chemistries, in between, like, a polymer ceramic that combine the best of both worlds. So, yeah, that's really good because what we've seen with solid state electrolytes is that they are far more resistant to the growth of dendrites, little branch like growths, which happen if you use or predominantly if you use a pure lithium anode.
Speaker 2:So rather than the lithium atoms pigeonholing themselves in between layers of graphite, in between layers of carbon, they would be placing onto a very thin bit of lithium foil. And if you do that in a lithium ion cell with a liquid electrolyte, the lithium ions don't do the sensible thing and coat uniformly. They start to form these little branch like growths. And those can puncture the separator, cause an internal short circuit with the cathode. And that allows electrons to rapidly, you know, move between the electrodes even if the cell isn't connected to anything.
Speaker 2:Rapid discharge, rapid, you know, heat generation and rapid, potential fire. So, you know, what we have what we have with solid state is the ability to use a lithium foil with vastly reduced likelihood of dendrite growth. It's not necessarily completely been eliminated, but there are efforts to completely eliminate it. And, you know, the results are looking quite promising. So once that is ready, once that can be commercialized, you're looking at, yeah, I just said the holy grail.
Speaker 2:Yeah. Because you've you've you've removed the bulk of having all of that carbon in the anodes because you require 6 carbon atoms to hold 1 lithium ion or 1 lithium atom in a lithium ion electrode. So you've just removed all that bulk. It means you can shove more active material in there because it's it's all lithium in the anode now, and that is a 100% of that anode could theoretically take part in the discharge reaction in a lithium ion cell. So very, very efficient.
Speaker 2:The separator or sorry. The the electrolyte, which replaces the separator now because it's solid state, could in theory be made quite thin as well. So, you know, you're it's all adding up to a very compact design, a very energy dense design. That's where you're getting those 500, 700 mile range EV ideas from.
Speaker 1:I see.
Speaker 2:And in theory, yeah, if you if you manage to harness the best of the ceramic, you know, electrolytes, then you could get rapid charging. You could also get improved temperature windows in which these cells could run. So they could actually deliver quite a lot of power in particularly cold Canadian winters. They could, you know, they could suffer from minimal degradation, heat based degradation in, like, you know, Dubai or somewhere like that. So genuinely, it's it's it's a pretty well suited chemistry to some extreme environments.
Speaker 2:But that said, you know, the existing lithium ion Gigafactories, which may not necessarily be perfectly tooled for creating solid state lithium cells, you know, 1,000,000,000 have been invested. 1,000,000,000 of dollars have been invested in all of these 100 upon 100 of gigawatt hours of capacity. So lithium ion is still here for the foreseeable future. There will be other chemistries which can be produced on lithium ion production lines like sodium ion, which you take a hit on energy density, but there's about a 30% cost reduction. So, you know, that would be used for your kind of cheap and cheerful entry level EVs that would be used for your electric buses and things.
Speaker 2:It would be a competitor for LFP. Interestingly, with LFP, though, we now have Tesla using LFP in the Chinese built model 3 because CATL, gigantic, you know manufacturer of our batteries over in China have developed this cell to pack packaging methodology that means that LFP which is less energy dense can actually be packaged in such a way that you can get a good couple of 100 miles range out of it, which was previously unthinkable. So, yeah, solid state. I think it will be used in premium EVs. It will be used in stupidly long range EVs, but I'm keeping a close eye on LFP because that, you know, and potentially by extension sodium ion because, you know, this cell to pack packaging methodology, you're combining that with a material which doesn't contain cobalt, doesn't contain nickel.
Speaker 2:I mean, it's iron and phosphorus. You know, so so it's basically made of rust. It's, you know, it's it's super cheap. And, you know, that is also safer. Yeah.
Speaker 2:Yeah. It's a safer chemistry as well. It's longer lived. You know, it's it's more ethical, etcetera. It has a lot of advantages.
Speaker 2:And we'd previously written it off for cars, but all of a sudden, it's making a resurgence. I would be very surprised if we didn't see more manufacturers adopting LFP over the next few years. So, yes, solid state definitely does have a place. But interestingly, the one that a lot of people had written off, the lithium ion chemistry that a lot of people had written off for cars is is making a comeback. This is interesting.
Speaker 1:Okay. I I I, you know, I don't have enough knowledge of of solid state to kinda I know they're they do have their applications. I think they're used in medical equipment.
Speaker 2:Oh, nice. Yeah.
Speaker 1:But, obviously, that's just, you know, like you said, there's a massive difference between what you have in your laptop or your mobile phone to what you have in in an EV. It's a completely different scale of of and and environment and the use patterns, which actually leads me to leads leads me, not reads me, to my last question. Mhmm. Because, the v to g used to be a massive thing that everyone was raving about, and it was supposed to be the future. And, you know, it it it is certainly usable in loads of places.
Speaker 1:But, obviously, most common household will have a 1 or 2 cars, and you will use them during the day, which is where you would charge it from sun, or whatever. And you could recharge it at night, but, you know, it's whenever it's either easy to charge or cheap to charge and usable to discharge, it's away or it's not charging, you know, this. It's a car. It's a different its purpose is different. The battery like, home battery storage seems to be on the on the app now, and there's a lot of companies of offering different, sizes of the minerals and so on and so forth.
Speaker 1:And, I I used to be a big proponent of v two g, but these but these days, I'm I'm thinking, we could probably design batteries that are cheaper, and we already probably have the technology to have those battery storage systems for houses, or domestic storage available. Where do you think do you think we need a different type of batteries for home storage, or do we already have it? What what's your take on it?
Speaker 2:Well, home storage, you know, you're you're looking at a usage pattern that's very different to an electric vehicle because it's a more predictable load. It's, it was far less dynamic. It's far less kind of stabby with harsh acceleration and regenerative braking. It's generally lower loads, more constant loads. So it's an easier life for batteries.
Speaker 2:And that's where you are gonna see a divergence towards cheaper chemistries that are maybe not necessarily as energy dense because there's more space to mount the home energy storage system or the commercial scale grid storage system. So, again, LFP looks quite promising there. I'm aware of some systems that use lithium titanate, which is particularly expensive chemistry, but it's very very long lived. And then the other option, which is quite interesting, is sec 2nd life electric vehicle battery modules because they may have 70 or 80% of their original capacity left, which is considered end of life for automotive. But that's a lot of capacity for grid storage.
Speaker 2:And that means that for a home energy storage battery, the likes of which PowerVault make from second life EV batteries, or at least one of their product ranges that they do ones with brand new cells as well. You know, you're you're looking at many years of of easy life for these cells, which would otherwise have been prematurely retired. So, yeah, I reckon we'll we'll see an interesting mix of the second life EV battery within the domestic energy storage scene. We'll probably see, you know, LFP, sodium ion. And then yeah, I mean, the the likes of Tesla, they are using NMC.
Speaker 2:The Powerwall, to be fair, has one of the highest capacities of any home energy storage system on the market at the moment, and it's also one of the cheapest per kilowatt hour capacity. One of the more expensive to buy, but you get a lot of value for money. So, yeah, the argument is do you really need to spend as a manufacturer do you need to spend money on cobalt, which is expensive, on nickel, which is cheaper? But then again, iron is even cheaper again. You know, these materials, do you need to spend big bucks on them for a battery system that's not overly space constrained and is gonna have quite an easy life?
Speaker 1:Yeah. Yeah. That's a to me, that's a very sort of interesting subject because I think more houses, especially in the UK, are are able to gain a lot of sort of economical, value from cheap energy store energy domestic and energy storage sort of Mhmm. Utilities, than from an EV, which is gonna be more expensive. But then the question is, you know, like you said, Tesla batteries are, home Powerwalls are very cheap compared to other competitors per kilowatt hour.
Speaker 1:But the the initial outlay is still massive. So there's a massive sort of gap, and I just wonder if there if there's, you know, a room for somebody to come in and say, okay. We have these 5 year old technology battery, production lines ready just to churn out loads of batteries that will fill in the gap. To me, that's that's where the sort of the market probably should be growing, but, you know, I I'm by no means an expert in the or analyst in that area. So
Speaker 2:Yeah. I mean, the the vast majority of production lines, realistically, you know, if if it's geared towards lithium ion, it should be able to do just about any variant of lithium ion, including newer, more modern chemistries, some of which are cheaper as well, you know, because you've got less cobalt content, etcetera. So in terms of making older cells with the the thinking that they would be cheaper, that's not necessarily gonna be true. However, you know, in terms of using a production line to to churn out sort of cheaper cell chemistries which are still quite sturdy and reliable etcetera for the home energy storage market that's that's absolutely something that could be done but the reason a home energy storage battery is more expensive than an EV battery is because EVs are selling by the, you know, tens, hundreds of thousands, that kind of idea. And the the order quantities for the likes of Samsung and Panasonic and all that, you know, the big cell manufacturers is absolutely vast.
Speaker 2:And that means that the unit price of those cells comes down considerably whereas home energy storage you know is taking off but the manufacturers are buying less per per product because you're typically single digits of kilowatt hours maybe just breaking into the double as opposed to double maybe breaking into the triple with EVs. And, also, they're selling less of them than EV manufacturers are selling of EVs. And as a result, you know, it's it's, economies of scale. So that's why you're looking at several £100 per kilowatt hour for a home energy storage system capacity. Whereas rumor has it, Tesla is now getting its hands on, I'll mention it again, LFP cells for between $60.80 per kilowatt hour.
Speaker 2:And, typically, within the EV world, you're looking at about sorry to mix up my currencies here, but a 100 to a 100 and £50 per kilowatt hour seems to be the industry average, for EV cells. Yes. And that's come down from about 10 times that when Nissan Leaf was first launched, and that that is continuing to decline.
Speaker 1:I I'm curious, like, your your day to day life as a as a sort of, as a battery expert. How I'm I'm sure there's gonna be people interested, and I think this is the you know, we need engineers and we need people who research these things. Pluck yourself in, like, you know, what do you do, how people can actually, if anyone had a commercial needs to contact you, And how do people if somebody's interest younger and interested, how do they become somebody like yourself? You know? Where where's the need, you know, in that sort of environment?
Speaker 1:I don't know. I've I've I don't have any particular question. I'll let you kinda have the floor ends and just say things. Mhmm. Mhmm.
Speaker 2:Well, I think, yeah, I I kind of had an unusual route into this because I did an applied physics degree called renewable energy at the University of Dundee. And, I I ended up getting into battery tech because the person who would become my project supervisor drove up next to me in a Peugeot 106 electric with NiCad batteries, which I would ultimately end up doing my projects on, buying off them. It would become my daily driver as I commuted from Dundee to Saint Andrews when I was working with Peter Bruce's research group there before they relocated down south and took me with them. So that car is now in a transport museum awaiting its next big adventure. Dundee, Museum of Transport.
Speaker 2:The intention is to fit new batteries to it, like cutting edge stuff at some point. Anyway, so, yeah, I I did an applied physics degree as I said, and then ended up getting into a PhD with an electrochemistry group. I would you know, in terms of if you're based in in England,
Speaker 1:in
Speaker 2:particular, then WMG, University of Warwick, and also just across the road from them, pretty much, Coventry University are doing some really cool stuff on battery research. And that includes engineering as well as the kind of hardcore electrochemistry side of it. And University of Birmingham is doing amazing work with battery recycling. Back up in Scotland, there are, you know, numerous different research groups within the kind of battery fields, but Saint Andrews remains one of the the more kind of prominent ones. So professor John Irvin mostly associated with fuel cells, but they've also got a big battery research group there too.
Speaker 2:So that's worth checking out. University of Edinburgh has been been dabbling in this as well. And, also, like, keep an eye on on what's happening over in the West Coast as well because within the sort of typical chemistry and electronic engineering sort of groups, you'll have people doing batteries and battery modeling and things. It's becoming an increasing you know, an increasingly big setup that, you know, for for universities to pursue. In terms of the best kind of degrees to have, certainly, physics is is highly transferable.
Speaker 2:And, you know, you can make it as basically, you can make it what you want it to be. So that's a pretty cool situation. If you're doing a kind of science y kind of degree like physics or chemistry, by all means, you can try and audit any more kind of electrochemistry goings on within your university if you know, if you're lucky enough to have a pretty good research group within that university. See if you can try and help out in the lab, that sort thing. They're normally quite good at taking on project students to assist and to learn and to quite possibly end up doing their PhD and their postdoc there someday.
Speaker 2:So that's a really good option for you. And then also you've got the likes of your chemical engineering degrees, etcetera, which could potentially help as well. But, yeah, it's actually quite difficult because I'm trying to think what did all of my yeah. What did all my colleagues do? Because it wasn't what I did.
Speaker 2:I was the kind of odd one out. But, yeah, anything that's broadly stem based, you know, will will will get you in the door, particularly if you if you show the interest. And then there's the other side of it as well. Like, those mechanical engineers are required for optimum cooling mechanisms and module designs, which includes, like, you know, modeling where the heat is going to accrue and bus bars and things like that, not just within the cells. Electronic engineers for the battery management system.
Speaker 2:Absolutely. So, you know, anything within kind of engineering as well as science. Civil engineers, it sucks to be you but everything else here you're in the door, you know, we might need to I don't know civil engineers. There's a lot of Gigafactories being built right now. Boom.
Speaker 2:There you go. You know, so that that definitely helps. But, yeah, that's the yeah. Those are the the best kind of routes to to go. And there's also quite a lot of, you know, now that now that COVID has hit, everything's kind of moved online.
Speaker 2:So, you've got quite a lot of webinars and teleconferences that are are coming up. And if you if you get involved in the kind of battery Twitterverse, then absolutely, you'll keep an eye out for those those sort of things. Actually, that also brings in brings into mind some other notable research groups to to check out. So you've got Billy Wu at Imperial College London and his team, Gregory Offor as well. It's kind of like this one big family, Dyson School of Design, Engineering Design, and Imperial College London doing some fantastic work on all things battery from the mechanical side, from the modeling side, from the electrochemistry side.
Speaker 2:Seifel Islam at University of Bath, one of the leading battery scientists in the country, he did the, the Royal Society Christmas lecture that was on the BBC a few years ago, an excellent educator. He's he's fantastic at putting these concepts across in a way that you can you can understand. And then also, it would be rude of me not to to mention my my former PhD supervisor. So I mentioned Peter Peter Bruce because he's now located at Oxford. And when I moved down there, I also started to work not just with Peter Bruce's research group, but David Howey's research group.
Speaker 2:And they again are probably more involved in the modeling and the battery management, the electronics side of things, but they are incredibly knowledgeable when it comes to batteries. And, yeah, they're excellent supervisors as well. So, you know, if you're if you're looking into PhD opportunities, that's kind of the main lot to consider within the UK at the moment. There will be a few more that will inevitably come to mind as soon as we finish recording this podcast. But, you
Speaker 1:know, those are the the kind
Speaker 2:of key ones that that that come to mind. Oh, so, yeah, the other one as well is if you go into academia and you're looking for a way into industry, well, I mean, for a start, if you go to WMG, basically, Jaguar Land Rover stand at the front doors with a net and just wait on PhD candidates.
Speaker 1:Like,
Speaker 2:boom. You'll do it. You're working for us now. So, you know, there's there's there's a lot of stuff going on there. But, I would also keep an eye within like, if you're if you're looking to go from academia to to academia to industry, another one that's absolutely worth keeping an eye on is Michelin Scotland Innovation Park, MSIP, up in Dundee, my adopted home city, where I I learned my trade and drove my first EV and so on.
Speaker 2:So it's the former Mitchell and tire factory, which closed down at the end of also the middle of last year and has been renovated into, an energy park, a renewables park, a an e mobility park as well. There are some very, very interesting businesses moving in there, and they are expanding, and they are looking for your expertise. We're talking batteries. We're talking fuel cells. We're talking, you know, the vehicles, the supply chain.
Speaker 2:There's there's all sorts of interesting things going on there. They are a very talented bunch. And then further north as well, you have Antipower and, Denshi Group as well, which have an interesting semi detached battery factory up as far north as you can get on the mainland in Thurso. And they are both doing some really cool things to do with next generation battery tech and battery systems as well. So if you fancy the the romantic nature of the Highlands and Islands of Scotland, which if you've seen my Sky road trip, you'll definitely want it.
Speaker 2:You'll definitely want to do that because it's just absolutely gorgeous. What What a fantastic setting to be. So they are absolutely worth checking out. If the West Midlands is just a bit too densely populated and a bit too concrete jungle for your liking. There's ways that you can have it both ways.
Speaker 2:You can have cutting edge battery stuff and the most incredible scenery on your doorstep. And, by the way, Dundee is an absolutely freaking amazing city as well. It's getting all the culture vulture write ups. Like, absolutely stunning city and I miss it every day. So, yeah, those are really really solid options to consider too.
Speaker 1:Yeah. I'm the the just going back to our conversation, I had a I had a thought when you were talking about the, and I might completely completely, butcher this, but the, you were talking about anodes and build up on the, and that electrons are not very good at kinda stuck laying flat basically on the anodes for lack of better, description. But I've always been told when I did, electronics that, the current will always choose the, the shortest path, the the path of least resistance. Is that, because of that or, is that why they build up in sort of a tree, as you said, or branches, you know, the growth that go gets on the anode or or builds up on the anode? Or or is it is there a different does the physics work different on that level from your
Speaker 2:Yeah. It could it could be to do with localized current density, and it could also be that, you know, the lithium ions are are going well. This, you know, dendrite is closest kind of path to to where I need to go, so I'm just gonna join on to that.
Speaker 1:Okay.
Speaker 2:Yeah. But there will no doubt be some localized current densities within the cell due to the the design of it, because it's, you know, with the exception of of Tesla's tabless, cell design, that's just actually in reality one gigantic tab that covers the entire edge of the cell to allow electrons in and out. You know, most cells, there's there's kind of limited areas through which the electrons can enter and exit the electrode structure. So, you know, you'll end up with those localized bits where the the current is that much more dense and, you know, there'll be more or less lithium that's either removed from that electrode in the 1st place or plating back onto it. So, yeah, that's that's kind of what's going on there.
Speaker 2:And then, of course, the path of least resistance once you've got an internal short circuit is the internal short circuit, and it just gets quite nasty from there.
Speaker 1:The the question I often get asked by people, and this is sort of, you know, like a geek geeky, me, thinks about that as well. Like, how how how do you actually work on the on the battery? What is the what is sort of day to day you know, do you just just change different things, you know, test a little bit of, you've got mixture of different components in the electrolyte. Or how do you actually come about researching the batteries? What is the sort of the the the workflow there?
Speaker 1:Are you do you have you know? Yeah.
Speaker 2:I mean, there's I've I've worked on so many different levels down to the the fundamental electrochemistry all the way up to kind of more pack design and integration. So it's it's it's too difficult to try and summarize that. But, yeah, there will be some career paths slash projects where you will be, you know, arms deep in an argon glove box, trying to assemble a prototype chemistry that you've developed from scratch, into a little coin cell, which will then go on to a battery tester to check its its performance at, you know, very small currents. But, obviously, the aim is that could be scaled up to something quite substantial. There'll be days when you're taking a commercial sale apart in that glove box to see what the degradation is like after a long run, of of cycling.
Speaker 2:You were doing, like, an automotive duty cycle, that kind of idea for for a couple of months. You know, they'll be setting up those tests where you're rigging up, you know, big modules and things and and preparing them for various different test procedures with, you know, varying temperatures, varying loads, varying, you know, like, other kind of electrochemical things you can do, like impedance tests and things that kind of detects what the the health of the battery is at that point. And then, you know, obviously, there's the the as I said, you know, there's the the more kind of module design as well. There's looking at a particular application and the available space and the chemistry that would allow you to get the capacity and the performance that you require, and kind of doing more of an engineering head scratchy thing around that. Yeah.
Speaker 2:There's I've I've kind of dabbled in in a lot of this over the last decade or so, and it's been quite nice to have that that broad range. I've I've worked with some very talented people who do the modeling side of it as well. So they'll find a way to, you know, to to mathematically mimic what is going on inside the cell. And then they can use that modeling to predict the remaining useful life of a cell based on a handful of cycles of of data. So you can say, yes, this particular cell because oh, sorry.
Speaker 2:Identical cells, there'll be a piece to piece variation between them on the same production line. It can be the silliest little thing that can result in a difference in the lifespan or the internal resistance of that cell. And being able to identify that very early on allows you to grade those cells and, you know, match them to appropriate applications or or grade them. So if you want the grade a stuff, you pay more. If you want the grade d stuff, then, yeah, it's pretty cheap.
Speaker 2:If you're just gonna be using it for home energy storage, not an issue. If you're gonna be using it in formula e, probably want the grade a, mate. You know, that sort of thing. Being able to to to grade that sort of stuff is a very expensive and time consuming thing to do. But with these, you know, these kind of clever models that they're coming up with in in in research groups and and businesses around the country, around the world, then, you know, the idea is to get that down to seconds ideally, and and do that reliably.
Speaker 2:So, yeah, we're getting we're we're now seeing mathematicians and and machine learning gurus coming in, who've never thought about electrochemistry before and taking electrochemists' efforts, best efforts at modeling and just smashing it out of the park. So this is is a really interesting time.
Speaker 1:Yeah.
Speaker 2:I mean, that said, you know, the modeling side of it is, you know, I'm I'm I've always been more fundamental electrochemistry, cell teardowns, cell, you know, cell and module testing and and and sort of next gen design, that sort of idea. I've I've supported a lot of modeling, but there's some some very bright minds who who do the kind of mathematical side of it. And, yeah, the what they've achieved has been incredible. I've been very lucky to work with a good 2 or 3 key people come to mind, and they know who they are, who've who've done some incredible things there.
Speaker 1:It does sound very fascinating. I I I used to work when I was much younger. I used to work with a lady named Bettina from Austria who, in her previous life, she was a SQL database, specialist, and she used to work for, I can't remember which one, a drug, research manufacturing company. And they were all do doing all their testing and modeling in in in databases. You know, ML and AI wasn't a thing back then.
Speaker 1:It wasn't called that. But it was essentially that. It was all modeling and, you know, all the theoretical. And I just wondered how that's like, the common question you would see you would ask these days is, you know, do we know how all the materials will behave if they were used for the battery? Is it just a matter of now kinda combining the one the best ones we know about and just testing them in in lab?
Speaker 1:Or is there still a lot of unknowns that we can discover in the future? Basically, it's the it's a simple question.
Speaker 2:Oh, yeah. I mean, we're we're starting to see, attempts to use modeling to be able to predict the best materials to use in batteries. That's definitely coming through, but there's still a lot of trial and error in the lab as well. Okay. For a start, you know, what the model says is actually a good material and then being able to make a prototype of that and then being able to scale that up to an automotive scale prototype and prove that it can last however many cycles, you know, before it dies.
Speaker 2:That's all a very different process, and that normally takes a few years, but the modeling should help to reduce that. Yeah. So, yeah, absolutely, that's something that we're starting to see. So if you are less hands on, but you're very good, sort of on a math c, machine learning, AI sort of side, you can absolutely get in on this. It's far more interesting than just copying out and doing the usual Fintech thing.
Speaker 2:It is. Yes. You know? If you wanna really help the world, then, yeah, this is this is the place to be. It's it's it's the Wild West at the moment.
Speaker 2:You could be the the next professor John Goodenough. You you could be the the the the godfather of the lithium ion battery. You could be the professor John Goodenough.
Speaker 1:He's he's amazing. Like, his
Speaker 2:life sight.
Speaker 1:If if if some if whoever's watching this never heard of, professor, Goodenough, Just stop watching this and just come back later, obviously, but just look him up. He's he's Oh, is it? Yeah.
Speaker 2:97. No. No. Well, 97 years old he was when he won that Nobel Prize. He was kind of like it was like when Leonardo DiCaprio finally won an Oscar.
Speaker 2:Everyone's like, about time. It's been so long. Yeah. I Do you have no idea how good this man is? So, yeah.
Speaker 2:And he's still going. He's still working away. He he just loves what he does. He's great. Yeah.
Speaker 1:Yeah. Well, I you know, like I said, I I I do have probably more questions, but I I, am conscious of of of the time. I did warn you that, you know,
Speaker 2:that this could
Speaker 1:go for a bit. This was an inter very interesting, discussion and, and, you know, no wonder everyone was telling me all the time, just speak to you and speak to you and speak to you. But, yeah, thank you very much for your time, and, and, hopefully, we can meet in person one day because, you know, I miss traveling and meeting people in in in face to face and talking to them face to face.
Speaker 2:True. Yeah. Yeah. I mean, eventually, there will be you know, hopefully, the the vaccination situation will go well this year. And certainly next year, I would hope that we'd have fully charged life.
Speaker 2:We'd have EVs in the park. We would have, well, Formula E in in London. Yeah. The intention is to make a cameo appearance at those at some point. So, yeah.
Speaker 2:Absolutely. If you if you spot me, give me a shout.
Speaker 1:All the all the Now you know how you look like. So
Speaker 2:Yep. There's no hiding. Absolutely.
Speaker 1:Anyway, thank you very much for your time. And hope to
Speaker 2:see is on. Cheers. Cheers. Thank you.
Speaker 1:Bye.
