A solid state car battery passed 1,000 charging cycles with 95% capacity left, and its maker says demand will outstrip its ability to produce them

What an independent test found

A solid state battery moves charge between its electrodes through a solid material, instead of the liquid inside an ordinary lithium ion cell. PowerCo, the battery arm of Volkswagen Group, ran an independent endurance test on a solid state cell made by QuantumScape, a battery maker Volkswagen Group first invested in during 2012. PowerCo ran the test in its own laboratories in Salzgitter, Germany, not inside QuantumScape. The cell completed more than 1,000 charging cycles and held 95% of its original capacity at the end, beating the industry standard for this development stage, 700 cycles with no more than 20% capacity loss. PowerCo says that cycle count equals more than 500,000 kilometres of driving in a car with a 500 to 600 kilometre WLTP range, the test used in Europe to rate how far an electric car goes on a full charge.

These are very encouraging results that impressively underpin the potential of the solid-state cell.

Frank Blome, chief executive of PowerCo, the battery subsidiary of Volkswagen Group. Source 1.

The cell that passed is still hand built

The cell PowerCo tested has 24 layers, the count QuantumScape already plans for series production. But in March 2024, 15 months after QuantumScape first shipped a 24 layer prototype to automakers in December 2022, it began shipping a newer prototype with only 6 layers. Neither company explains the drop. QuantumScape said in December 2023, the date on its own page, that a lot of work remained, including reliability and scaling up production, before its cells would be ready for commercial production.

Why the first cars will be expensive

QuantumScape says plainly that once it starts selling cells, demand will outstrip its own ability to produce them, and outstrip the ability of any single vendor to produce them at all. That statement, not a price tag, is the clearest sign of what a first generation solid state car will cost. A product nobody can make enough of goes first to whoever pays the most, or to a manufacturer proving a technology rather than selling it at volume. Nissan, building its own solid state cells rather than buying from a supplier, aims to launch a car with one by fiscal year 2028, 2 years after QuantumScape expected to manufacture its first QSE 5 cells later in 2024. Nissan names pickup trucks as a target segment but confirms no specific model, and says its cells will eventually cost less from cheaper materials, without giving a dollar figure, a percentage or a date.

We are very encouraged by the initial Alpha-2 performance results and excited about the first QSE-5 cells we expect to manufacture later this year.

Dr. Siva Sivaram, president and chief executive of QuantumScape. Source 4.

What happened last time a battery chemistry scaled up

None of the 5 sources behind this article states what a solid state battery pack costs, including the 2 companies making one. The nearest comparison is ordinary lithium ion batteries, the kind in nearly every electric car sold today. The United States Department of Energy estimates an electric vehicle lithium ion pack cost 1,355 dollars per kilowatt hour in 2008, when the industry built them in small batches. By 2022, once manufacturers bought at a scale of at least 100,000 units a year, the department put the price at 153 dollars per kilowatt hour, a fall of 89% over 14 years. Solid state cells are not lithium ion cells, and nothing here says they will fall the same way. But no battery chemistry in this industry has shipped cheap while still hand built in a lab for a handful of cars, and a company that expects to run out of cells the day it starts selling is describing a launch, not a market.