Episode 109: 10-minute EV charging with Adden Energy

Molly Wood Voice-Over: Welcome to Everybody in the Pool, the podcast where we dive deep into the innovative solutions and the brilliant minds who are tackling the climate crisis head-on. I'm Molly Wood. 

This week you know what would really make people want electric cars? Batteries that charge in 10 minutes. 

Specifically, solid-state lithium metal batteries not the same as lithium ion with self-healing capabilities that mean they can be safely charged super fast over and over 

And can be produced using existing battery manufacturing. 

Then, obviously, we’ll get to robots. 

Let’s jump in.

Will Fitzhugh 

Sure. So my name is Will Fitzhugh. I'm one of the co-founders and the CEO of Adden Energy. Adden is a three-year-old Harvard spinout developing next generation batteries. And we can dive into the details of what I mean by that. But long story short is we're targeting principally the electric vehicle market, aiming to close the gap, if you will, between

Internal combustion vehicles and electric vehicles so that we can enable the masses to adopt electric vehicles. There are other applications we're targeting as well. Our batteries are a lot of things. They're lithium metal, which you've probably heard of before that's really key to the higher energy density. They're solid state batteries, which is how we enable the lithium metal.

What's really unique about our batteries is this concept of self-healing within the batteries, which is how we're able to achieve such great performance. namely, charge rate is our biggest value proposition. So we can fully charge in just under 10 minutes, targeting as fast as gas charging.

Molly Wood 

All right, we're gonna take that apart piece by piece. So first of all, let's start with the problem that you're solving. What is, you I think we all have a vague sense that there are things wrong with EV batteries as we know them today, but what is wrong with them that you're trying to overcome?

Will Fitzhugh 

Let's do it.

Will Fitzhugh 

Well, I think in general, the problem is that there's a lot of different market segments in vehicles. Obviously, if you buy a Porsche, you're a very different consumer than if you buy a Toyota. You have all sorts of different needs. The batteries that are on the market today...

work great for the people that they work really well for. Only about 2 % of vehicles on the road in the United States are electric. I'm one, I drive an EV. It works great for me. I have a parking spot at home I can charge every night. I don't have long distances. I have like a 15 minute commute. Works great for me. With regards to our battery in particular.

About 40 % of Americans don't have dedicated at home parking, so they can't charge overnight. So current lithium ion batteries are really a struggle for them. They need that gas station paradigm where they can charge on their way to work or picking up the kids without being there for an hour. so that's one market segment that just can't.

really electrify well with existing technology and it's where our batteries charging in less than 10 minutes can electrify a new market segment. One thing that you'll hear me say often is that we're not competing with lithium ion batteries, we're competing with the internal combustion engine because we're not trying to re-electrify people who have already electrified it, we're trying to go after new market segments that for whatever reason haven't been able to electrify and bring them some value proposition that makes it

finally enables them to make that transition.

Molly Wood 

And then talk about it, just in case people are not aware, talk about what you mean when you say solid state battery and what the difference is between that and lithium ion.

Will Fitzhugh 

Sure. So, I think the, the real motivating factor is the lithium metal battery. Sounds a lot like lithium ion. It's worlds apart.

It's in the anode, lithium metal is the highest energy density electrochemical material we know of. It's top left of the periodic table. The only things that are lighter are hydrogen and helium and their gases. So if you're talking about, okay, let's get the most energy dense battery we can. This isn't, it's not an option, right? It's, there is only one choice and it's lithium metal.

We've known that for a long time. There were primary lithium metal batteries back in the 1980s. We have not been able to date to make them successfully recharge without.

these things called dendrites forming dendrites are these little spiky structures that grow inside of the battery. if you take a, a lithium ion battery, which uses a liquid electrolyte and you just put in a lithium metal anode, what will happen is those dendrites will grow in inside of the liquid electrolyte that fills the battery. And it'll eventually short circuit the cell internally and cause a catastrophic failure. So you get internal short circuit that leads to a huge onrush of.

of current which heats up the battery which ignites the liquid electrolyte and then you get what's called thermal runaway. So yes, yeah. And one that you can't use water to put out by the way because lithium metal is very reactive with water. So yeah, you've got to burn. So that's kind of the context.

Molly Wood 

really big fire. Just gonna hang up. The thing we are all trying to avoid. Yeah.

Will Fitzhugh 

Liquid electrolytes just can't make lithium metal work, but we want it because that's how we get the higher energy density, which means longer range, means smaller batteries, can drive down costs. So the idea was, okay, well, let's replace this liquid electrolyte with solid electrolyte so that these dendrites can't grow the way they do in a conventional battery. Turns out it...

Dendrites can still grow in solid state batteries. What happens is instead of growing within the electrolyte itself, as the battery ages, you'll have cracks form in the batteries. And then the dendrites can grow through those cracks. And what...

What's kind of the last piece of the puzzle, if you will, for our batteries, and this was a nature paper at Harvard in 2021, was figuring out a way to have the battery heal any cracks that form. Cracks are inevitable as any electrochemical system ages. Have those cracks heal so that there's never a pathway for the dendrites. So in that, we were able to enable lithium metal for the first time, but...

On top of that, we're actually able to really push lithium metal to the performance limit. And that's how we get the high charge. So the combination of higher energy density and then the ability to charge it fast is our unique advantage.

Molly Wood

Yeah. I want to geek out more on self-healing and dendrites, but it feels like a good point to take a step back and talk about how these discoveries were made. Like how has the scientific process gone to the point that you then spun out of Harvard as a startup?

Will Fitzhugh 

Yes.

Will Fitzhugh 

I would love to think that it was all planned out, but, I think we, got pretty lucky. So, I guess the, the story kind of starts.

Molly Wood 

If you said it was, I wouldn't believe you.

Will Fitzhugh 

fall of 2015. it my first semester as a PhD student in applied physics at Harvard. It was also a new junior faculty's first position, or first semester there as a faculty member, Professor Shen Li. I was originally working with a different professor, didn't really get along with the group, wasn't excited by the project, had a class with Professor Li, really liked him as a professor, joined his

group as the first PhD student just based on kind of the human aspect was wanted to work with him. At the same time, there was a visiting undergraduate, Lou Hanye, who later became a PhD student at Harvard and is now our chief technology officer at Adden Energy. And so the three of us started working on solid state batteries back then, 2015. At the time,

Solid state batteries were starting to pick up in popularity. Almost everybody focused on a type of solid state battery called an oxide. It's all electrolyte based battery. This is kind of the quantum scape material.

We wanted to pick a little bit less studied field, no commercial aspirations at this time. was just, you we wanted to do some exciting science. So we went with an alternative, which was the sulfide based solid electrolyte family of solid state batteries. That was kind of, guess, lottery ticket number one that we won, just picking the right chemistry to focus on. At this point, I think everyone's really consolidating around sulfide solid state batteries, but at the time we didn't know.

Um, and so, you know, by, from 2015 on, was just a science project and we went through and, um, studied all the different components of the battery. So from the fundamental material stability of the, sulfide solid electrolyte to how you design cathodes and anodes to work.

Will Fitzhugh 

with this material family. In 2020, I graduated, went down to Oak Ridge National Lab in Knoxville. Luhan, at that point, had become a PhD student and continued to run with our project. And in 2021, he and Shin published this amazing self-healing.

separator technology in nature, which was the first, I think it's still the only sulfide solid state battery paper ever in nature. And that was, you we had, we had made a lot of innovations, but with batteries, if you've got even one piece of the puzzle that's missing, it's, it doesn't have commercial potential. This was that last piece. And so all of sudden,

where we had been doing really exciting science. Now listen, we had a battery with a value proposition that goes pretty far beyond lithium ion. And we felt, obviously we were very excited to commercialize it, but also felt a sense of obligation. We'd been working on this technology for so long and it was time to move on. we, yeah.

Molly Wood 

Yeah.

And then just to clarify this meeting, the self healing properties, that was the final piece of the puzzle that made this like, we can totally build these at scale. huh. Okay.

Will Fitzhugh 

Correct.

Exactly. So company formed summer of 2021 on paper, spent the next

six months or so, licensing the IP from Harvard. There were kind of three and a half patents that we had developed at Harvard that we were licensed. So one was in the works. We ended up licensing that a little later as well. And then closed a seed round in February of 2022, which was really when Aden was born in its full capacity. And since then, it's just been

know, full steam ahead at first it was, we put this in a pouch cell? Then later it was, can we produce these pouch cells on roll-to-roll production environments, which for us is a mandate. What that means is that we can use lithium ion manufacturing infrastructure. We don't have to invent any new manufacturing procedures, which...

I guess in theory maybe you can do it, but in practice trying to introduce any kind of new manufacturing while also introducing a new battery design, it's just, it's not viable. So we've, we've now done that quite successfully. have a roll the roll production line at our facility in Waltham. It's all the same components as a gigafactory, but much smaller. Everything's slurry casted on slot dies, roll the roll.

Will Fitzhugh 

process stacked just like a gigafactory.

Molly Wood 

Yeah. All right, so let's go back to the technology then. tell me more about the self-healing separator that is kind of the core of this technology. So it sounds like dendrites may still occur, but they will just get trapped. They'll have nowhere to go.

Will Fitzhugh 

So you can have dendrites start to grow, but they won't be able to pass the separator. the dendrites are on the side of the anode and it's not an issue until they reach the cathode, which is the opposite side of the battery. correct. That's catastrophic failure, as we like to say. The way that...

Molly Wood

So if they punch through to the cathode, collapse. Disaster.

Catastrophic failure, thank you, yes.

Molly Wood 

I like to inject a little action movie excitement, which is probably somewhat inappropriate considering how bad those fires can be.

Will Fitzhugh 

needs.

Will Fitzhugh

we can get some fun animations.

Molly Wood 

I'm in.

Will Fitzhugh

so the way that that penetration usually happens is you have what we call percolated network of, of defects in the separator. So you have some holes in the separator where the material didn't go down and just ride. And then you've got some other places where the material broke and it ends up being a pathway. can walk along all those defects from the anode side to the cathode side. And what's tricky about lithium.

dendrite formation, the material science term for it is a growth instability. It basically it's like water on a leaky roof. If there's a pathway, it will find it. so it will just keep growing around along the defects until it reaches the cathode. So if there's even one path, your batteries will fail. and then there's no, yeah. Correct.

Molly Wood

Got it, but if there's not a path, the water just runs off and everything's fine. Okay. So the dendrites don't just keep filling the space until like, like the blob.

Will Fitzhugh

And what, but what makes it a.

Will Fitzhugh 

No, so the dendrites are quite small. They're on the order of nanometers wide. So you can imagine as you grow the dendrites, you're losing lithium metal to those dendrites. And that certainly is happening. It's happening so slowly relative to the operation of the battery that we can neglect it. I mean, we still get thousands of cycles of lifetime in our batteries, which is what you need for electric vehicles.

I will, we'll add what makes the, this problem particularly challenging is that one, when you manufacture batteries, lithium ion batteries are made, they're slurry coated, so it kind of looks like a, newspaper printing press, just like sheets coming out. The sheets are coming out about a hundred meters a minute to, that's how fast a gigafactory has to operate. So in order to not have any defects, you can imagine how challenging that process is.

Molly Wood 

Yeah, that's some specific machinery and I assume you cannot allow any dirt to get in, things like that. Like clean room, is this like clean room manufacturing?

Will Fitzhugh 

But.

Will Fitzhugh 

yeah. mean, I mean, right. In solid state batteries, we do it in dry rooms, but it's the same, same idea. So we're restricting humanity. so, so it's in fundamentally a messy process that is prone to defects. That's, that's challenge number one. but even if you could make the perfect, even if you could print a newspaper with no tiny microscopic defects in the ink, right.

The batteries themselves can crack as they age. They will crack as they age. It's called pulverization. Sometimes it's bad. Sometimes it's not bad, but it's always present. And that's basically the materials that make up the battery. As these lithium ions are shuttling back and forth, they swell and shrink and that causes cracking. It's unavoidable. so with lithium metal, once that cracking, even if you made the perfect separator, which you can't, once that cracking occurs to the point

that you have a percolated pathway, then you've got a dendrite penetration. So it's in one part, it's about making the manufacturing easier by having this self healing. So you have a higher defect tolerance. And then on the other end, it's making sure that you can preserve that defect free separator throughout the lifetime of the battery. And that really requires an active healing method. It's not a thing that can just be done at manufacturing and then left alone.

Molly Wood Voice-Over: Time for a quick break while you digest that. When we come back, we’ll talk about how the self-healing thing works but also what kinds of vehicle types this technology could unlock and where it goes after that. 

Molly Wood Voice-Over: Welcome back to Everybody in the Pool. We’re talking with Will Fitzhugh of Adden Energy about what is apparently one of my new favorite topics containing dendrites. Who knew??

Molly Wood 

Great. Okay, so then talk to me about as much as you think that I will understand the self-healing process.

Will Fitzhugh 

So it's an electrochemical process. We have two different sulfide solid electrolytes in our separator, which is unique to us. So if you opened up the separator, what you would see that would be surprising, and this is what was discovered in that nature paper, is we call the tri-weir separator. So there's one family of solid electrolyte on the outside of the tri-weir separator and a separate one on the inside.

And the middle layer, the solid electrolyte is engineered to electrochemically react any time it is in contact with a defect. So if there's a hole, a void in the separator that's touching that middle layer, dendrites will start to grow into it. And when they do and they touch that middle layer, there'll be a electrochemical reaction between the dendrite and that layer.

And that reaction is unique in that it expands volumetrically. So it balloons to fill in the defect. And that really cuts off the growth mechanism right at the tip of the dendrite. So the dendrite doesn't have anywhere else to go.

Molly Wood

mental animation for this is that it gets like a tiny little shock and then just there's a little like a Marvel movie energy shield that forms and pushes the dendrite back down. We're gonna do this. We're gonna get a whole animation. It's gonna be like the next K-pop Demon Hunter. like, this is gonna be so cool.

Will Fitzhugh

Amazing. We have to come up with a catchy battery name.

Molly Wood 

Yes, for sure. Ooh, all right, I'll work on that while you talk. No, I'm just kidding, I'm listening.

Will Fitzhugh 

So it's really this volume expansion whenever this middle layer comes in contact with the dendrite that is the key to making it work so that the dendrite, the defects themselves have a finite volume. This middle layer expands to fill in that volume and now there's no more defect.

Molly Wood 

So, all right, now that we generally speaking understand the science at the level that I'm capable of, let's talk about the plan going forward. You've said that your primary focus now is electric vehicles, but also that you're not necessarily looking to replace existing lithium ion. Like who are the, you what are the types of vehicles that you would target first?

Will Fitzhugh 

we, we talk with, with every, every global automaker you, you can think of, we talk with, and most of them, we have some kind of engagement with them. you know, their, their chief concern is how do they electrify their, customers, at least for the legacy aliens, it's a little different when you start talking about like Tesla or Rivian or, or one of them that was born as electric vehicles. But if you're.

Molly Wood

All of them.

Yeah.

Will Fitzhugh 

any legacy automaker. The question is, how do you build a vehicle that's going to electrify a market segment with that isn't yet electrified? And in general, they've been pretty good about electrifying markets where lithium ion batteries are good enough.

What they haven't been able to do is figure out any alternative for the remaining markets and the remaining markets are huge. 40 % of Americans don't. Yeah. Yeah. Right. Um, so every, every automaker has their.

Molly Wood

Yeah, the other 98 % basically.

Will Fitzhugh 

Next generation battery targets. Typically they have a lot of them. This is our, this is, you know, if we're doing a long range vehicle, this is what charge rate we need. If we're doing a fast charging vehicle, this is what range we need. All these, these various, targets almost always add an energy can fill one of those kind of, we don't know what battery is going to be able to fill this set of targets.

Molly Wood 

So it's interesting because what I hear you saying is that there's a future where automakers will have multiple vehicle classes with multiple battery technologies, right? Like, is that what you're saying? Like there will just be city cars with lithium ion batteries, but there will be the Montana relatives, in my case, car, you long range vehicle that charges in 10 minutes at a gas station. And that's a paradigm I actually haven't heard before. Like you'd have a sedan and a midsize, but the battery would be different.

Will Fitzhugh 

Yeah.

Will Fitzhugh 

I-

Yeah, I totally think that you're going to see like brand identities based around and not just batteries, but certainly including batteries. Today, you really only have two choices, right? You have high performance transition metal oxide cathode. So like NMC, NCA, et cetera.

Or you have the, the economical grade LFP. So if you go and you buy a Tesla and you buy the base model, you get LFP, you buy the long range model, you get an MC. That's really the only differentiation that's out there. there's a whole lot more differentiation to be had with not just our batteries, but all sorts of next generation batteries. And.

To add to that, think automakers in many cases are pretty desperate for brand identity in a world that doesn't involve the things that they're famous for, which are their motors and their transmissions and all these moving parts.

Molly Wood 

Right? So you can have a performance class that is dependent on battery technology as opposed, I mean, they already do to some extent, but it's sort of like additional range and more torque. But you're saying you could even, you could play with that a little bit more. So you're like, this is our smallest lightest vehicle that doesn't go that far, maybe. You're Miata.

Will Fitzhugh

Yeah.

Will Fitzhugh 

Right. maybe, maybe there's, yeah, the, the Miata that charges at home versus, what's another, Mazda six that, can charge in, 10 minutes or, you know, any number of options.

Molly Wood 

Yeah. Yeah, fascinating. And then what comes after that? Because I know that the Adden energy vision for battery technology is, you're starting. There's always a beachhead, but that you're looking beyond that.

Will Fitzhugh 

Yeah. I think what excites me the most is we're going through a massive industrial change. think electrification is the biggest industrial change of our lifetime for sure.

Vehicle electrification is a place where we really clearly see what the future holds. mean, everybody knows that in the future vehicles are electric for any number of reasons. I they're just better vehicles. They're cleaner, they're more pleasant to drive, they're better performance, lower lifetime cost of ownership. What's exciting to me are the things we can't even imagine yet because we don't have the power sources for them. Maybe humanoid robotics is kind of one step.

Further than EVs, we're starting to see them. There's some companies doing some exciting work. They're not definitely not mainstream. Power is a major, major issue there. Things like electric aircraft, whether that's advanced drones or it's passenger aircraft, any sort of industrial application. These kinds of things are always held back by the power supply. Internal combustion engine.

just doesn't have a place in those kinds of futuristic applications. Right. No one's going to think of a humanoid robot, robot powered by a little internal combustion engine. It, it, your house like cooking you breakfast. Right. but the HMIM batteries just quite frankly, aren't up to the task of those heavier industrial applications. So EV's really good one, robots, aircraft.

Molly Wood 

It's not like a lawnmower.

Will Fitzhugh 

autonomy, we're already seeing a lot of strain on the grid because of data centers and the AI boom. But I guarantee you there's a lot more things that are going to exist in 50 years that don't exist today because of a lack of energy supplies. And as someone who's trying to commercialize this technology with a very differentiated value proposition, that's what gets me the most excited is it's like, what is it that we can't even fathom that these batteries can enable?

CUT TO: 

Molly Wood 

Got it. So you're solving for safety, charge time, energy density. How does that compare economically? What do the future costs look like? And acknowledging as I always do that you are not yet at scale.

Will Fitzhugh 

Exactly.

Will Fitzhugh

Yeah. so the promise of lithium metal has always been one that ultimately reduces the cost of the battery. The materials are more expensive in terms of dollars per pound, but you get more energy per pound. So you need less of them. And of course it depends on the exact design for us. we're our designs come out.

We're about 30 % cheaper than a comparable lithium ion battery at the same scale. Assuming, you know, the assumptions around supply chain development and everything continue on track. But energy density in general is the best way to reduce the cost of the battery because you just need less of it.

Molly Wood 

Right. So then what are the milestones for you as you continue to grow? What are next steps to that kind of mass adoption?

Will Fitzhugh 

So, I guess starting.

Molly Wood 

I mean, could you just start dropping into like lithium ion manufacturing facilities tomorrow? Really? As long as I say yes.

Will Fitzhugh 

so our process, yeah, fully, fully compatible with that. They have to say, yes, it's not trivial to drop in. And so you don't want to go back. You don't want to go be going back and forth. Often between lithium ion and solid state batteries, but you certainly can do it once. And that is something that we're actively pursuing as a number of,

We built our prototyping line, which makes up to 20 amp hour pouch cells of our batteries next stage. For pouch cells, you really need to be 50 to 60 amp hours or above for electric vehicles. We have a couple of partners who have already built out facilities that meet that demand and we're looking to drop into them in the next, probably later 2026 into 2027.

be producing these full-scale automotive cells with a very small fraction of the capital that's been required for previous iterations of battery companies to get to the same stage.

Molly Wood 

That's great. So you want to have vehicles on the road in 2030? That's what you're saying?

Will Fitzhugh 

I want to have him on the road tomorrow, but I think... I think...

Molly Wood

Well, yeah. Incumbency being what it is. What is it? I mean, I guess that's actually kind of the question I think I'm dancing around. What is your biggest barrier right now?

Will Fitzhugh 

man. it really depends on which partner you're talking about. So some auto, I'm not going to name names cause I don't want to get in trouble, but some automakers, legacy automakers, you know, they have four or five year development cycles, which means from the moment they decide to use your batteries, you're four or five years away from their customers driving around on top of your batteries. Some automakers are even longer, like eight years.

Some of the startups are, I call them startups, non-legacy automakers, can be faster, like two years. So we're taking an all of the above approach and working with as many people as we can. think realistically, inoperable vehicles, but test vehicles by the end of 2027. And then...

commercial, yeah, towards the end of the decade, unless we can get one of the earlier state or younger, more innovative EV companies to endorse us.

Molly Wood 

Will Fitzhugh is co-founder and CEO at Adden Energy. We'll be looking for those vehicle types.

Will Fitzhugh 

Amazing. And the battery K-pop Demon Hunter is here pretty soon too.

Molly Wood 

That's right, Battery K-Pop Demon Hunters. keep, hello Netflix, we're waiting for your call. Thanks so much for the time.

Will Fitzhugh

Thanks, Molly.

Molly Wood Voice-Over:

That's it for this episode of Everybody in the Pool. Thank you so much for listening.

I’m laughing because I am legitimately such a battery nerd that after we stopped recording I asked 50 million more questions about when batteries get hot and when they get cold and how do you cycle them thousands of times in the labs and blah blah blah I really have a problem. Will was very patient. 

ANYWAY. Email me your thoughts and suggestions to in at everybody in the pool dot com and find all the latest episodes and more at everybody in the pool dot com, the website. And if you want to become a subscriber and get an ad free version of the show, hit the link in the description in your podcast app of choice.

Thank you to those of you who already have. Together, we can get this done. See you next week.