LiF as an Alloy Component or Slurry Additive in Si-Alloy Anodes

Electrolyte additives are commonly used to improve electrochemical performance in Li-ion cells. The use of solids as electrolyte additives is far less common. Here, Si40′(FeSi2)(60−x)′(LiF)(x)′ (′ = volume percent) alloys with LiF incorporated in the alloy as a solid electrolyte additive are studied. Improved capacity retention was observed for LiF-containing alloys with x < 12, with optimum performance at x = 6. Improvements in electrochemical performance of Si-Fe alloys were also observed when LiF was introduced as a slurry additive. The use of solids as electrolyte additives may be a valuable method for improving electrochemical performance of Si-alloy negative electrodes.