Silicon Batteries with High Energy and Power Density for Electric Mobility

Amprius is continually improving its pure silicon anode with nanowire structure that has enabled lithium-ion batteries with energy density and specific energy performance exceeding current state of the art graphite cells by 50-100%, in different cell sizes and form factors. The rooted nanowire structure has very good mechanical stability, electrical conductivity, and connectivity, and allows material expansion within the structure, extending the cycle life to hundreds of cycles. Amprius cells have shown that silicon anode-based batteries can reach 1,300 Wh/L and 500 Wh/Kg while maintaining a cycle life compatible with aerospace, military, and other high-end applications. Moreover, the open nanowire structure enables cells to function at high rates of charge and discharge without overheating, achieving 3000 W/kg power density in cells with over 400 Wh/kg specific energy density. Recent cell design optimizations have substantially improved resilience to thermal runaway conditions, such as internal short circuit and nail penetration, all critical performance parameters for electric flight applications.