Quinone-Imine Enhanced PVA Binder: A Universal Strategy for High-Loading Electrodes With Low Binder Content in Li/Na-Ion Batteries

Phosphorus/carbon (P/C) composites are promising high-capacity anode materials for lithium/sodium-ion batteries due to their high specific capacity, good rate performance, and electrochemical reversibility, coupled with low material cost. However, large volume changes during cycling, especially at high active material loading, hinder performance. This study introduces a novel polymer binder system composed of polyvinyl alcohol (PVA) and benzoquinone imine (BQI), crosslinked through a network of abundant intermolecular hydrogen bonds. This binder exhibits superior dynamic viscoelasticity, effectively accommodating the significant surface area variations and relative movement of active material particles during cycling. The strong adhesion ensures robust bonding between all electrode components, including the current collector. PVA contributes inherent flexibility and elasticity, while BQI enhances tensile strength and modulus, improves ionic conductivity, and promotes better wettability with conductive carbon for a more uniform distribution within the electrode. A P/C electrode prepared with 5 wt% binder loading, exhibiting an areal capacity of 10.20 mAh cm⁻², demonstrates a capacity retention of 71.26% after 60 cycles–significantly surpassing other binder-based P/C anodes. This advance promotes the practical application of phosphorus-based anodes.