Sericin-Regulated Aqueous Network Binder for High-Performance Si─C Anodes and NCM811/Si─C Pouch Cells

Silicon-carbon (Si─C) is a highly promising high-capacity anode material, yet its commercialization is hindered by the significant volume expansion of silicon and complex interfacial issues. While binders such as polyacrylic acid (PAA) and carboxymethyl cellulose (CMC) are commonly employed to accommodate volume changes of silicon, their high polarity leads to poor adhesion with nonpolar carbon materials. Herein, silk sericin (SS), a natural polymer containing aromatic rings has been introduced to regulate PAA and CMC to formulate a ternary binder named PSC for Si─C anodes. During electrode drying process, the PSC binder in situ constructs a cross-linked network with abundant ester bonds and hydrogen bonds. The unique structure enables dual-interfacial binding: polar groups anchor silicon via hydrogen bonds, and aromatic rings adhere to carbon via π-π interactions, contributing to improved interfacial adhesion and a uniform dispersion of electrode components. A full pouch cell using the Si─C anode based on LPSC binder (formulated from CMC, SS, and the commercial E300L, a LiOH-neutralized PAA binder) and NCM811 cathode retains over 74% of its initial capacity after 300 cycles at 1 C. This work provides a practical binder strategy facilitating the commercialization of high-performance Si─C anodes.