A Physically Cross-Linked Hydrogen-Bonded Polymeric Composite Binder for High-Performance Silicon Anodes

High-capacity silicon (Si) anodes in lithium-ion batteries require functional binders to accommodate the dramatic volume change and to improve the long-term stability during the charge/discharge cycles. Herein, a physically cross-linked hydrogen-bonded polymeric complex is reported and employed as an efficient binder for high-performance Si anodes. Composed of a blend of two commercially available polymers, poly(acrylic acid) (PAA) and poly(ethylene oxide) (PEO), the proposed PAA-PEO binders are synthesized via the solution mixing process. It is revealed that PEO brings in better elasticity and ionic conductivity, but at the expense of lower adhesion properties. With an optimized composition, the PAA-PEO binders show better cycling performance for Si anodes than the pure PAA binder. This study would provide insights for the design of low-cost and efficient binder for electrode materials with huge volume changes.