Battery developer QuantumScape Corporation has released results from an independent third-party laboratory testing report on the performance of its solid-state lithium-metal battery cells.
The firm’s single-layer cells met automotive-relevant conditions, achieving more than 800 cycles— roughly equivalent to 240,000 miles driven for a 300-mile range vehicle, say the firm.
The results, from testing conducted by Mobile Power Solutions, go some way to answering questions over the company’s technology, or at least its claimed progress.
The results reflect a complete cycle-life test that demonstrates conditions the company believe must be met, which include: operating at 25 °C, 1C (one hour) charge/discharge rates (with energy retention maintained at more than 80%), 100% depth of discharge and under 3.4 atmospheres of pressure.
Jagdeep Singh, CEO and co-founder of QuantumScape, said: “We are happy that these independent test results substantially replicate the cycling performance we reported at our December 2020 Battery Showcase.
“With the publication of this report, we will continue to focus on our product roadmap goals and delivering cells to our customers.”
Mobile Power Solutions is an independent battery laboratory, ANAB accredited to ISO/IEC 17025:2017, based in Beaverton, Oregon.
The full cycle life test report from Mobile Power Solutions is available here.
Quantumscape believe the results, covering a group of three single-layer cells, are consistent with those initially reported by it last December, and subsequently questioned the following month.
The company’s stock price tumbled by around 41% on 4 January following a report on Seeking Alpha website by Dr Brian Morin, CEO of Soteria Battery Innovation Group, that questioned the technology’s capabilities.
At the time, Morin said that QuantumScape’s technology did not meet its claimed data on low temperature operation, low temperature life and energy density.
He said in the Seeking Alpha report: “They show 100 or so cycles at -100C. Respectable, except that these cycles are at C/5 charge and C/3 discharge. Thus, not 80% in 15 minutes, but rather 5% charge in 15 minutes.”