Fraunhofer silicon-rich battery cells keep 83% capacity after 1,000 cycles, but only under high pressure

Fraunhofer ISE researchers have shown silicon-rich anode pouch cells can hold more than 83% of capacity after over 1,000 full cycles, reaching 280 Wh/kg at cell level. The cells use a silicon-carbon/graphite anode with a nickel-rich NMC cathode and were built on a semi-automatic pilot line. The catch is mechanical pressure: the retention figure only holds at 1,000 kPa, while lower pressure caused faster capacity loss. The work targets stationary storage of surplus solar and wind, along with electric mobility and aerospace. Silicon-carbon composites could reduce reliance on graphite and shift raw material value toward Europe. An industrially optimized pouch format is expected to reach about 330 Wh/kg. The project is part of Germany's StrOboBatt effort, with €2.6 million in federal funding.