Silicon Based High Performance EV Batteries

Nanomakers is a French start-up that manufactures at industrial scale four types of nanosilicon for high capacities Li-ion batteries for electric vehicles (EV): Those ultra fine particles are produced with narrow particle size distribution by laser pyrolysis. This process is reproducible, robust and the particles have low oxygen contents. The existing Li-ion technology uses for the anodes graphite with 350 mAh/g capacities. Nanomakers particles enable the manufacturing of high capacities Li-ion batteries anodes: 800 mAh/g along with a good capacity retention along cycling (>100 cycles). For silicon anodes, various formulations are studied but the most promising uses pre-composite in which the silicon is dispersed in a carbon matrix which is then partly decomposed by a thermal treatment. It is processed at a much lower temperature than graphitization processes. This micronic pre-composite can then be used as a high capacity raw material for anodes without changing anode preparation existing processes. The use of carbon-coated particles improves the anode performances during cycling, especially the capacity stability. This presentation compares the results obtained with various preparations and types of particles. The carbon coating has a positive impact on the batteries performances.