Influence of the Binder properties on Silicon Anode for Solid-State Batteries

Silicon (Si) has been considered as one of the most promising anode materials because of its high theoretical capacity of 4200 mAh g−1. However, the huge volume change and side reactions upon cycling cause poor cycle performance and limit a use of Si for the commercialization. Recently all solid-state batteries open up new possibilities for an introduction of high capacity electrode materials due to their ability to operate under compression, which can mitigate electrode volume expansion. Herein, we study an effect of multifunctional polymeric binders on silicon anode for all solid-state batteries enabled by a sulfide Li6PS5Cl electrolyte. The Si electrode manufactured by a single rigid polymer shows stable electrochemical properties because of applied external pressure and potential hydrogen bonds between carboxyl groups and Si particles, resulting in a mitigation of a volume change. In addition, an introduction of multifunctional network binders to the Si-based electrode leads to a high discharge capacity of 3000 mAh g−1 and stable cycle performances at room temperature.