“We simply want to be better than the existing battery technologies.” That’s the goal of Ilika and its research into the commercialization of solid state batteries. In this interview, John Tinson, Vice President of Sales at Ilika gives an insight into the current state of development and the challenges involved in developing their Goliath cells.
From Medical Applications to Electric Car Batteries: Company Profile Ilika
Ilika was founded in 2004 as a spin-out from the University of Southampton based around combinatorial materials development. Following a pivot in 2018 Ilika focused on the development of solid state battery technology, both at mm-scale (Stereax) and large scale printed cells (Goliath). Stereax , mm-scale, solid state cells are designed to power active implantable medical devices (AIMDs) and customers have been sampling first generation batteries. Since the 2018 pivot, Ilika has also been working on an all solid state battery for the automotive market. Unlike many competitors, the plan is to use silicon as the anode material. Oxide materials will be used as the solid electrolyte. The planned solid state cells are called Goliath (see figure1) and will have a capacity of 80 Ah. A cooperation with Nexeon was announced in early 2023. Nexeon develops battery materials and will develop a high silicon content anode based on its low expension NSP-2 material specifically for solid state cells for Ilika.
A-Sample pilot production is planned for 2025. Production will then be scaled and improved by the end of the decade so that larger-scale production can take place starting in 2028.
Figure 1: Ilika’s planned 80 Ah solid state battery for use in the electric car (“Goliath”). Image provided by ilika. All image rights by ilika.
Interview with John Tinson, Vice President of Sales at Ilika
John Tinson (picture on the left) is Vice President of Sales at Ilika and, as a physicist by study, is also familiar with all the technical challenges surrounding the development of the solid state battery. In this interview, he provides insight into the current development and challenges associated with the commercialization of the solid state battery:
Hello Mr. Tinson. Beginning of 2023, you have announced a collaboration with Nexeon and other partners to integrate high-silicon anodes into your Goliath solid state Battery. How is the project going?
Tinson: We started development two or three months ago, so we are still at a quite early stage. We are part of the Faraday Battery Challenge No. 5, a government program for collaboration between science and industry. The program is called HISTORY (“HIgh Silicon conTent anOdes for a solid-state batteRY”). We plan to make history. It’s as simple as that.
Nexeon is the anode supplier for this project and will develop the silicon anodes. We have been developing the NMC cathode and electrolyte for the last 4 years. In our prototypes developed outside of the program , we have been evaluating a range of silicon and graphite materials. Nexeon will develop a silicon anode specifically for us. They already have a silicon anode, but they are listening to our requirements to develop the most beneficial material for our solid state battery. I think it will be a few months before we get the first samples to use in our system. Right now there are a lot of meetings and discussions about what the silicon samples should look like and how we can integrate them into our system
Are there also some plans to implement Li-Metal as anode material?
Tinson: No, we have always been very focused on silicon anodes. We already offer a small medical battery that also uses a silicon anode, so we can draw on our experience here. So when we came to look at the pouch cell for electric vehicles the plan was always to have a silicon anode.
For the high-silicon anode, are we talking about 100 % silicon or is it a mixture?
Tinson: No, we use a mixture for several reasons. One is to limit the expansion. Secondly, there is a cut-off point, which we believe is 50-60%, above which a certain percentage of the silicon anode no longer provides any benefit.
There are some concepts with very thin silicon anodes, but this is something different, and there are big challenges for mass production. We are also testing it outside the program, but inside the program it will be the hybrid composite structure. This composite structure with silicon inside makes it possible to minimize expansion, which is actually the biggest concern in making a silicon anode.
You are one of the first companies which are already selling solid state batteries for medical purposes. What are the similarities and differences between solid state batteries for automotive and for medical applications?
Tinson: To be fair, there are not many similarities. The program to make very tiny medical batteries for use in very small medical devices started a few years earlier, and we use a semiconductor-based process for 6-inch wafers. We use thin film deposition and photolithography patterning techniques, which are on a completely different production scale than in the automotive industry. For our solid state Stereax battery, we use LCO as the cathode material, while the cathode in automotive is NMC. The electrolyte material is LIPON, while the automotive electrolyte material is LLZO.
The similarity is probably in the anode. We use a sputtered silicon anode with a layer thickness of a few micrometers in the Stereax battery. The graphite-silicon composite structure, on the other hand, is used in an electric vehicle. They are both solid state batteries. They are both ceramic objects. But the manufacturing techniques and materials are actually very different.
You are using Oxide-based electrolytes for your Goliath technology. Oxide-based electrolytes are known for their bad interface between anode and electrolyte. How do you deal with these issues?
Tinson: It is the challenge. The conductivity and impedance between the layers is the challenge. overcome with interface modifiers. One of our steps is to sinter the active layers – though not at as high temperatures as you might think. We’ve actually managed to significantly reduce the temperature when sintering.
If you use a sulfur-based electrolyte material as an alternative, its reactivity is a challenge. It is not a very nice material at all to use in a factory. Its reaction with air is causing acidic outcomes. But this reaction could also occur in a battery in the field. So there are both issues in the factory with handling and production and potential safety issues in the field if you choose sulfide-based electrolyte methods. That’s why we chose oxides, and that’s our challenge to make this work.
Solid state batteries are advertised for their higher safety and lower risk of thermal runaway. However dendrite growth is one of the big problems of solid state batteries. How is your estimation of safety for Goliath solid state Battery?
Tinson: The answer depends on the definition of safety: safety can mean, first, avoiding catastrophic failure, and second, what happens if it does fail.
For the dendrites: We have seen no evidence of dendrites in our solid state batteries. A lot of people claim to have a solid material, and then it turns out to be semi-solid or polymer with a high percentage of liquid or gel. So there is a lot of confusion about what a solid state battery even is. Ilika uses a solid solid state battery. So we don’t see dendrites, which would concern us.
We also show videos at our conferences where we cut a solid state battery in half to show that it is a safe object. Our ceramic cells are safe in that context, you can damage them and cut them and they remain safe. What we also see is the ability to operate at high temperatures, and it has a very high thermal runaway temperature. And that’s very useful for battery designers from a safety standpoint.
A full understanding of the effects of catastrophic failure can only really occur once we reach the targeted 80 Ah and have done long-term testing with them. We’ll tell you a lot more about that, but to be fair, we haven’t reached that point yet. So it’s unfair to make claims that I can’t back up with data.
Which are the targets you want to achieve with the first commercially generation of your solid state technology for automotive market?
Tinson: We first want to see what we can achieve. And then we start talking to OEMs. We simply want to be better than the existing technologies. We don’t try to reach too extreme goals. That can take a long time, or you’ll make claims that you’ll never be able to meet in the early stages. We want to increase the capacity of the cell to 350 Wh/kg, which is slightly better than existing technology, but at the same time is safe and has the high-temperature capability that is the unique selling point of solid state batteries. What is also necessary is that we achieve a cycle life of at least 800 cycles, which we think is sufficient.
It is probably possible to work on a solid state battery for many years and end up with a battery that achieves an energy density of 400 Wh/kg. Because theory says that 450 Wh/kg should be possible. This might be done by using very thin foils, which is a major industrial challenge in manufacturing.
In the early stages, one should not overdo the challenges. So the idea was to leave out some of the challenges that fully push the technology towards its limits and address them later, and focus on creating something that is actually already better than what currently exists. That’s also what the OEMs are telling us. Just make it better than what exists today and be safe and solid. And then you’ll have something that we consider a viable product. And that’s our first challenge over the next two years: to get to the A-sample of something that’s better than what exists today.
How will solid state battery technology evolve in the next 10 years? How advanced will solid state batteries be by then, and how dominant will they be in the market? Where does Ilika see itself in 10 years?
Tinson: Depending on when people started, it depends on when they finish – I mean A sample, B sample, C sample. We’ll see A-samples and B-samples in the middle of the decade. Then it’s a long way to mass industrialization before they become affordable. And that’s the second part of the journey, which could be a challenge in itself. Because in order for a car to be affordable, you have to reach a giga scale. And industrialization at giga scale is in itself a challenge. So I think the first good samples of solid state batteries will certainly be available in the middle of the decade. And then towards the end of the decade they will be used in cars. They could be quite expensive cars, because they’ll probably start with low-volume vehicles. So I don’t think we’ll see any mass roll-out of solid state batteries until the beginning of the next decade. Of course, that brings us to the question: what is solid state? These might be some early examples that could be quasi-solid state or semi-solid state, but true solid state batteries are still several years away from production.
However, I think the deployment outside of the automotive sector will happen sooner than that. The funding is coming from the automotive sector, and that’s the reason people have focused on that sector so far. When you get millions from the investment community, it’s hard to say we might try something else. Recently, there have been announcements that the first applications will be outside of the automotive area. That’s a pretty smart move. I think most solid state companies will follow that move. Because the time to market is less. And you can then get more data from this non-automotive application.
But the bigger expectation, of course, is the change in automotive technology that can be built around solid state. And that’s going to be something that we’re not going to see until the end of the decade and beyond.
Thank you for the interview!
More information about Ilika can be found here: https://www.ilika.com/
