Hello. I'm Chris Egnesian, Principal Product Lead at QuantumScape. Today, I am joined by Daniel Braithwaite, Senior Director of Cell Manufacturing at QuantumScape, and Dr. Venkat Viswanathan, Associate Professor, Mechanical and Aerospace Engineering at the University of Michigan. Daniel, can you tell us a little bit more about your work here at QuantumScape?
Thanks, Chris. Yeah, as you mentioned, I'm the Senior Director of Cell Manufacturing. What that means is I'm responsible for design, process development, and assembly. I've spent almost two decades now in the energy industry, three years here at QuantumScape. Originally, back in school, I was a student of Professor Fritz Prins, who is a co-founder of QuantumScape.
Venkat?
Yeah, I'm a faculty member at the University of Michigan. I've worked on batteries for a long time. I've also been a technical advisor at QuantumScape for a while, and a member of the Scientific Advisory Board at QuantumScape.
Before we start, as a public company, I'm obliged to tell you that any forward-looking statements, such as projections of our technology performance, are subject to risks described in our SEC filings. If you've been following QuantumScape news, you'll remember that we introduced a new flex-frame battery format. We also promised that we'd share more information on this innovative new format. Today we're excited to do just that. Currently, lithium-ion batteries are produced in a variety of formats. Venkat, can you take us through these form factors?
Yeah, sure. Lithium-ion batteries are primarily produced in three formats. They're usually either put in a cylindrical case, a prismatic case, or in a pouch cell. These all strike various kinds of trade-offs in being able to have a higher fraction of active material, and thermal, mechanical, and electrical aspects. When you move to lithium metal batteries, that introduces new challenges. One of the main challenges is the fact that you now have very large volume expansion and contraction, uniaxially, in one direction when you discharge and charge. That's very different than what you have with lithium-ion cells, where the amount of contraction and expansion is only of the order of a few %. Managing this makes the challenge of designing the cell format for lithium metal batteries quite unique and different from what we have for conventional lithium-ion batteries.
Thank you, Venkat. As part of the product team here at QuantumScape, I'm intimately familiar with our product roadmap as we work towards what our customers require. We recently introduced this new format, flex-frame. Daniel, can you talk a bit more about flex-frame and how this new format addresses these challenges?
Sure. Yeah, absolutely. As Venkat mentioned, lithium metal batteries expand and contract. They grow and shrink in thickness during charging and discharging. The fact that the anode is pure lithium metal with no host material to house the lithium ions is what gives lithium metal batteries a lot of their desirable properties. That also presents some unique challenges when designing around this expansion and contraction behavior. To address this challenge, we created flex-frame. In some ways, flex-frame is a hybrid between a pouch and a prismatic battery, which is engineered to give our lithium metal batteries the environment in which they perform best. The flex part of flex-frame is this flexible, movable interface that provides for the expansion and contraction of the active stack from the charge and discharge cycle of lithium metal batteries.
The frame part of the concept provides an internal structure that supports the flexible laminate and enables easy handling and stacking of the batteries into modules for automotive and other applications. That's why we call it flex-frame. We're introducing a new category of battery cells, which combines elements of both pouch and prismatic batteries that accommodate the unique behavior of solid-state lithium metal batteries so that we can provide the higher energy density, faster charging, and safer cells that we believe differentiate QuantumScape batteries from others on the market. It's important that flex-frame is a hybrid of two mainDaniel Braithwaite
Of course, there are some nuances that are different because of how our technology works. We don't do it exactly the same as how others would do it. We can leverage a lot of the same supply base, vendor capabilities, and general infrastructure that's available to the broader battery industry. Our ceramic separator is a groundbreaking innovation that's pretty unique in the battery industry. That's involved a lot of new material and process development. For the rest of the battery, we're trying to leverage as much of the existing infrastructure in the battery industry as possible. We believe that reduces our risk to execution and should help us to get to market faster.
Thanks, Daniel. Venkat, what does having a lithium metal anode mean for fast charging?
Yeah, so that's very interesting. Conventional lithium-ion batteries are limited by fast charging because of the problem of plating lithium. Lithium metal batteries work by operating by plating lithium metal. This presents a unique opportunity for lithium metal batteries to have much higher fast charging. Of course, that means that when you can charge fast, say in 15 minutes, that also leaves a thermal burden on the battery. That means that you have to figure out a way to get the heat out. I think that presents sort of thermal challenges that need to be addressed in order to enable fast charging that is enabled by the fundamental material science of lithium metal batteries.
Yeah, exactly. Right.
Fast charging is a key benefit of our lithium metal solid-state battery. Fast charging also requires an increase in the performance for thermal management of the system. The battery generates heat during charge and discharge cycles. It is that much more important to dissipate the heat during fast charging. Those of you that own an EV probably know that your vehicle has a sophisticated system that manages the temperature of your battery pack for optimal performance. That thermal system in your vehicle is designed around the specific properties of the battery that it's supporting. We're seeing different automakers taking different approaches to thermal management, much the same way that internal combustion engines took different approaches to their engine designs. I think we're still in the early days of what EV thermal management systems will look like.
It is an exciting time to be introducing a new tool or building block into the automaker's toolkit that allows them to tackle the challenge of thermal management in new ways. Flex-frame provides for efficient transfer of heat throughout the cell, through the sides of the cell, and out the back face. We believe that this is the best way to conduct heat in and out of the cell and control the temperature during charging. The thermal system of a vehicle is in part dependent on the properties of the cell, because that's where the heat is generated, and in part dependent on the design of the system around the cell. We're currently working with our partners to develop and validate the thermal management systems, which include our cells in vehicle pack designs. I'm excited to see the results of these efforts.
In a lot of ways, we're still in the early days of the EV industry. New designs and new concepts will continue to be developed. We're excited that flex-frame is now part of the solution space for designing EVs. We're looking forward to the day when a vehicle using flex-frame cells, which capture the benefits of our higher energy density, safer, and faster charging cells, is out on the market.
Thanks for that great explanation, Daniel. Venkat, can you tell us what you think about the flex-frame?
Yeah, sure. You know, as a material scientist that's been working on lithium metal batteries for a long time, I've always wondered what the right cell format should be for accommodating this very large volume expansion and contraction that is produced because of the fact that you don't have now a hosted anode. It's very exciting to see this new design. I think it'd be very exciting to see how this manifests in larger format, multi-amp hour pouch cells, and how that plays out in modules and systems in automotive applications.
Absolutely. The A0 prototype cells that we delivered to customers were in the flex-frame format. We were very pleased with some of the results that we've seen, achieving 1,000 cycles with greater than 95% energy retention. Venkat, can you tell us what these results mean for the industry?
Sure. The cycle life requirement has been the thorn for the commercial adoption of lithium metal batteries. Being able to achieve a long cycle life is a critical requirement for EVs. If you had a 300-mile car, and if you can achieve 1,000 cycles, that gets you an EV about 300,000-mile range over the lifetime of the vehicle. Now, that's a critical requirement because customers want this requirement as they use their EVs over decades. The achievement here is very significant. Of course, as a cell engineer, you're always on the edge of your seat waiting for the cells to cycle. It takes many, many months. It's delayed gratification. It's exciting to see the performance achieved by the QuantumScape A0 prototype cells.
Absolutely. In a previous webinar, we discussed the energy power performance frontier. Daniel, can you talk a little bit about how we can get to high energy densities with the flex-frame?
Sure. Yeah, thanks, Chris. We talked about the A0 prototype cells before, which is an early version of our flex-frame battery format. Now, with our QSC5 cell, what I have here is a mockup, which has no active components. It's a 24-layer cell, just like the A0 prototype cells, except you can see that it is quite higher energy density. The flex part of it, which is the laminate, and the frame part of it, which is the internal structure of the cell, add minimal overhead to the design so that we can keep the high energy density we're looking for.
Thanks, Daniel. Can you also comment how the manufacturability compares to other designs?
Sure, yeah. Since we're leveraging a lot of the same tools and materials that pouch and prismatic cells use, I would say it's just as manufacturable. One of the goals of the design is to make it so that we don't have to reinvent the wheel.
Great. How can the cell be integrated into a pack or module design?
The cell is designed so that it can be easily stacked, like other prismatic or pouch cells. The design of it also allows for heat transfer out the sides and the back of the cell.
What work remains before the B sample design is done?
We set our focus on moving from our first 24-layer A0 prototypes, which we shipped at the end of 2022, to a first commercial product design. Beyond A0 prototype shipments, we plan to focus on subsequent generations of prototype samples, incorporating advances in cell functionality, process, and reliability, as well as bringing online the manufacturing capability our consolidated QS0 line is designed to provide.
That's really exciting. Venkat, any final thoughts?
It's a really exciting time for the field of lithium metal batteries. I've been working on this problem for about two decades now. It's exciting to see all the progress that's happened in the field, and I'm looking forward to the road ahead towards seeing lithium metal batteries in the inside of cars.
Yeah, we absolutely all are. Daniel?
The core QuantumScape technology represents a step change in battery performance. Now we're combining this with this new innovative flex-frame format to bring all the advantages of lithium metal technology to the market. This is an extremely exciting time at QuantumScape.
Couldn't agree more. Thank you both for sharing this great information and your thoughts. Thank you to the audience for joining us. We hope you're as excited as we all are about this new innovation. Please be sure to visit www.quantumscape.com to keep up with our updates. We hope you'll continue to follow us on our journey to a better battery.