The Next Big Thing
Solid-state batteries have been touted as the “next big thing” in battery technology. Lighter, more compact, and more flexible than their lithium-ion counterparts, solid-state batteries could enable the next generation of electric cars – giving them more range, more space, and making them cheaper to produce.
At the end of December 2022, QuantumScape corporation, one of the major players in solid-state technology, and a partner of numerous car manufacturers, shipped its first prototype solid-state batteries for testing. Built on lithium-metal architecture, these initial samples represent an important step towards the commercialization of solid-state batteries.
How do these solid-state batteries work? With 24 layers, each QuantumScape battery has a solid-state separator, a cathode, and a shaped lithium-metal anode. With capacities in the multi-amp-hour range, the company believes they are relevant not just for automotive applications; in smaller sizes, they could also be used for consumer electronics.
What makes solid-state batteries special is that they can store energy more efficiently and reliably than today’s lithium-ion batteries. They deliver high energy density while lowering material costs and simplifying the manufacturing process.
What Makes Solid-State Better?
Lithium-metal solid-state batteries should in theory charge faster, go farther, last longer and operate more safely than today’s EVs and gas-powered vehicles – helping to bring more of us closer to a lower-carbon future.
QuantumScape’s lithium-metal batteries replace the polymer separator used in conventional lithium-ion batteries with a solid-state separator. The carbon or silicon anode used in conventional lithium-ion batteries becomes a lithium-metal anode. The anode is more energy-dense, allowing the battery to store a greater amount of energy in the same volume.
Interestingly, QuantumScape’s “A0” cells, which have just been shipped, actually expand and contract depending on the state of charge. The architecture of the cells, a hybrid between the “pouch” battery cells commonly used in electric car batteries, and a more shaped “prismatic” design, expands and contracts in just one direction.
The company claims that, at a target of 1,000 Wh/L (watt-hours per litre) would translate to more range for electric vehicles if the batteries take up the same amount of space – potentially 50 to 80 percent more. Alternatively, the size of the battery could be reduced, lightening the car, taking up less space, and improving overall efficiency.
Automakers Begin Testing
QuantumScape still has a lot of work ahead to bring its solid-state batteries to market, including improvements to the quality, consistency, and throughput of its production processes. It also plans additional enhancements on the product side, such as increased capacity loading and improved packaging efficiency.
QuantumScape has partnered with a number of vehicle manufacturers, and the Volkswagen group, which owns VW, Audi, Porsche, Bentley, and Lamborghini, among others, was an initial investor. The first prototype cells will allow engineers at the car brands to start the testing process and provide feedback on the performance of the new cells.