Silicon anodes for lithium-ion batteries produced from recovered kerf powders

Abstract

Silicon kerf waste from a photovoltaic silicon production process is assessed as an anode material for application as a lithium ion battery anode. In contrast to previous studies, the Si-kerf is used as-produced, with no chemical treatment or physical processing beyond solvent PEG removal. The as-produced Si-kerf performed as well as, or better than, previously reported Si-kerf anodes and is found to outperform a cleaned Si-kerf sample from blade sawing with a larger particle size. This highlights the advantage of the diamond wire cutting process, which yields relatively small particles. In half-cell testing, a cycle life >300 cycles at a capacity of 1000 mAh g−1 is achieved with high levels of FEC addition. Full-cell testing against an NMC 442 cathode resulted in specific capacities up to 150 mAh g−1 (NMC). A relatively high degree of lithium consumption arising from repeated SEI formation is present. It is concluded that pure Si-kerf is unsuitable for commercial application in Li-ion cells.