Engineering Mechanically Adaptive Nanonetworks for Long‐Life and High‐Capacity Silicon Anode Batteries

ABSTRACT

Silicon anodes, with a theoretical capacity of 3860 mAh g ^{− 1} , offer more than ten times the lithium storage of graphite but suffer from large volume expansion during lithiation, leading to particle fracture, electrical disconnection, and unstable solid–electrolyte interphases (SEIs). In this study, we present a rheology‐guided materials design strategy that leverages viscoelastic single‐walled carbon nanotube (SWCNT) nanonetworks to construct mechanically adaptive, electrically resilient silicon anodes capable of preserving electrical percolation, dissipating lithiation‐induced stress, and stabilizing the SEI. By tuning polymer binder chemistry and silicon particle size, we form percolated conductive networks that accommodate strain while maintaining interfacial integrity. The optimized Si‐SWCNT anodes, with a carboxymethyl cellulose binder, showed a yielding onset over 10 times higher than polyvinyl pyrrolidone‐based controls, an initial Coulombic efficiency approaching 89%, high capacities across a wide range of rates, and over 51% capacity retention after 100 cycles at 0.5 A g ^{− 1} . In‐situ Raman mapping and electro‐chemo‐mechanical simulations confirm that the optimized networks minimize stress concentrations, promote uniform lithiation, and suppress interfacial degradation. These findings establish a framework for electro‐chemo‐mechanical regulation in silicon anodes, achieved through mechanically adaptive nanonetworks, as a scalable pathway to structurally robust, high‐energy lithium‐ion batteries.