Bio-Inspired Binder Design for a Robust Conductive Network in Silicon-Based Anodes

Due to the severe volume variations during electrochemical processes, Si-based anodes suffer from poor cycling performance as the result of a collapsed conductive network. In this regard, a key strategy for fully exploiting the capacity potential of Si-based anodes is to construct a robust conductive network through rational binder design. In this work, a bio-inspired conductive binder (PFPQDA) is designed by introducing dopamine-functionalized fluorene structure units (DA) into a conductivity enhanced polyfluorene-typed copolymer (PFPQ) to enhance its mechanical properties. Through constructing hierarchical binding networks and resilient electron transportations within both nano-sized Si and micro-sized SiO_x electrodes via interweaved interactions, the PFPQDA successfully suppresses the electrode expansion and maintains the integrity of conductive pathways. Consequently, owing to the favorable properties of PFPQDA, Si-based anodes exhibit improved cycling performance and rate capability with an areal capacity over 2.5 mAh cm^–2.