Ion-Conductive Enhanced Binder for Stable SiOx Anodes in Lithium-Ion Batteries

SiOx exhibits considerable potential as an anode candidate for high-capacity lithium-ion batteries due to its much higher theoretical capacity in comparison to traditional graphite. However, it still suffers from large volume changes and poor ion conductivity. The binder plays a crucial role in silicon-based anodes, requiring both good mechanical properties and ion conductivity. In this work, a PG82 polymer binder synthesized from PAA and GG is developed, integrating ionic conductivity and mechanical reinforcement, aiming to improve cycling stability and reversible capacity. The PG82 binder exhibits a lithium-ion diffusion rate twice that of the poly(acrylic acid) (PAA) binder. Using the PG82 binder, the SiOx electrode achieves a high capacity of 975 mAh g–1 at 500 mA g–1 after 350 cycles. When applied to a full cell, the SiOx@PG82||NCM622 full-cell demonstrates an impressive 86% capacity retention at 0.5 C after 100 cycles.