Silicon-mediated polyacrylic acid and ethylene vinyl acetate (PAA/EVA) dual-crosslinked network binder for highly stable lithium-ion battery anode

High-capacity silicon (Si) anodes for lithium-ion batteries are limited by severe volume expansion during lithiation, resulting in the low stability performance. This condition is pushing innovations in both material synthesis and binder design. This study demonstrates the development of dual-crosslinked PAA/EVA network binder paired with Si synthesized from rice husk ash via a vacuum-magnesiohydrothermic reduction process. Optimization of the SiO 2 :Mg precursor ratios (1:1, 1.5:1, and 2:1) revealed that the 1.5:1 ratio (Si-1.5) produced the most favorable characteristics, including a uniform 65 nm globular morphology, 95.3% purity, and 17.65 m 2 g −1 of surface area with dominant pore size of 2.14 nm, indicating its mesoporous properties. Electrochemical evaluations demonstrated that the PAA/EVA dual-crosslinked binder significantly outperforms conventional PVDF binder. The Si-1.5/PAA/EVA system exhibited a charge transfer resistance of 11.43 Ω (compared to 24.56 Ω for PVDF) and an initial capacity of 1850 mAh g −1 , maintaining 1701 mAh g −1 after 150 cycles. Notably, the system achieved 93% capacity retention over 400 cycles, while Si-1.5/PVDF suffered a 37% loss by 240th cycle. The superior performance of PAA/EVA dual-crosslinked binder attributed to the synergistic effects of hydrogen bonding, covalent crosslinking, and elastomeric stress dissipation, which creating a self-healing network and preserving electrode integrity and mesoporous accessibility. Mechanistic analysis confirms that this network prevents the pulverization and delamination characteristic, which is occurred in PVDF binder. These results establish a commercially viable strategy for high-energy-density silicon anodes through the integration of morphology, porosity, and binder engineering.