Long-term performance of micro-silicon-based anodes in lithium-ion batteries enabled by mechanical reinforcement of aqueous binders

Abstract

Silicon-based anodes offer exceptional theoretical capacity for lithium-ion batteries, but their severe volume fluctuations during cycling limit long-term performance and commercial viability. Here, we report a multifunctional binder additive composed of lithium cations and nanographene-derived multivalent anions that reinforces conventional aqueous binders through covalent, hydrogen, and ion-dipole interactions. This engineered binder network significantly enhances the mechanical flexibility, adhesion, and structural integrity of silicon-based electrodes. When applied to diverse silicon materials (silicon oxide, micro-silicon, and Si/C composites), our system effectively redistributes cycling-induced mechanical stress, reducing initial volume expansion by 43% compared to conventional binders. The enhanced electrodes demonstrate remarkable stability through 600 cycles with minimal capacity fade. This widely applicable strategy provides a scalable pathway to overcome long-standing challenges in silicon anode commercialization, enabling practical implementation of high-capacity silicon materials in next-generation lithium-ion batteries.