Carbon Networks Enable Durable Alloy Anodes for Na-ion Batteries

• • The 9226-SWCNT electrode (92 wt% Sn, 2 wt% SWCNTs, 6 wt% CMC) achieves 87.6% capacity retention after 6000 cycles at 2 A g−1, demonstrating exceptional long-term durability for micrometre-sized Sn anodes. • • SWCNTs act as a mechanical barrier preventing cold welding of Sn particles (Mohs hardness 1.5) during electrode manufacturing, enabling scalable processing without agglomeration. • • The high-aspect-ratio SWCNTs transform electrical contact from point contact to face-to-face contact, maintaining electrical continuity despite ~420% volume expansion during sodiation/desodiation. • • Topological analysis using the first Betti number (β1) reveals that 2 wt% SWCNTs yields a higher β1 (more porous coral-like structure) than 4 wt% SWCNTs, indicating that excessive conductive additive hinders sodiation-induced morphological evolution and reduces performance.