Volkswagen-backed solid-state battery startup QuantumScape released data showing its battery cells have completed 400 consecutive 15-minute fast-charging (4C) cycles from 10% to 80% of the cell’s capacity while retaining well above 80% of the initial energy – a first for this type of battery technology.
QuantumScape conducted the tests on commercially relevant sized single-layer prototype battery cells at multiple temperatures (25 °C and 45 °C), 3.4 atmospheres of pressure and 100% depth of discharge.
Internal combustion engine vehicles can be refueled in about 5 minutes, whereas today’s leading lithium-ion electric vehicle batteries typically need around 30 minutes to fast charge from 10% to 80% capacity at a rate that doesn’t reduce the battery’s lifetime. This longer charge time prevents EVs from providing the same user experience as internal combustion engine vehicles. If QuantumScape can successfully deliver today’s demonstrated capability into the marketplace, the time difference between recharging EVs and refueling their combustion-engine counterparts will be only several minutes, which could help enable broader EV adoption.
The materials used in today’s EV batteries, such as the graphite in the anode, have physics-based rate limitations that can cause permanent damage when charged repeatedly at fast rates, reducing the range the vehicle can travel. This can put EV drivers in the position to choose between the convenience of fast charging and preserving their battery range. QuantumScape tested battery cells from a commercially available third-party EV with the same protocol and found that those third-party cells rapidly degrade after only a few dozen charge cycles.
QuantumScape’s lithium-metal battery cells retained more than 80% of their initial energy after 400 cycles of 15-minute (4C) fast charge between a 10% and 80% state of charge. For a vehicle with 400 miles of range, 400 cycles represent approximately 160,000 total driving miles.
“We believe QuantumScape’s lithium-metal technology provides a pathway to significantly improved fast-charging performance in EVs,” said Jagdeep Singh, co-founder and CEO of QuantumScape. “We believe innovations like this are crucial to narrowing the performance gap between EVs and combustion-engine based vehicles, and represent the future of the electrified transportation sector.”
QuantumScape’s fast-charging results are detailed in this new white paper.