Californian manufacturer QuantumScape is working on reducing charging time of its solid-state lithium-metal battery cells. Data resulting on massive tests (here a white paper with the results in details) carried out at the company’s labs showed that 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. 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.
QuantumScape believe it’s possible to have faster charging time
Today’s leading lithium-ion electric vehicle (EV) 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. According to the US-based manufacturer, 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.
«A pathway to significantly improved fast-charging performance in EVs»
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».