Reaction‐Driven Coupled Transport–Nanostructure Evolution in SnSb Anodes for High‐Energy All‐Solid‐State Li‐Ion Batteries

ABSTRACT

All‐solid‐state Li‐ion batteries (ASSLIBs) require high‐performance anodes exhibiting high capacity, high rate capability, and long‐term cycling stability; however, existing anodes suffer from sluggish transport kinetics, particle pulverization, and unstable electrode–electrolyte interfaces. Herein, a SnSb anode overcoming these limitations via reaction‐driven coupled transport–nanostructure evolution during electrochemical cycling is reported. The transport evolution originates from the reaction‐driven formation of continuous mixed ionic–electronic conducting pathways and nanostructure evolution arises from repeated conversion and recombination reactions that induce stabilized nanocrystallization. This coupled evolution dynamically reconstructs mixed‐conducting pathways during lithiation–delithiation, suppresses particle agglomeration, preserves intimate contact with the Li ₆ PS ₅ Cl solid electrolyte (SE), and lowers interfacial resistance, enabling rapid and highly reversible electrochemical reactions. A SnSb|NCM811 full cell delivers an areal capacity of 28.97 mAh cm ⁻² at an ultrahigh cathode loading of 200 mg cm ⁻² and maintains ultrafast rate capability over 1000 cycles at 10 C. Using an optimized 30‐µm‐thick SE sheet, the full cell is projected to achieve gravimetric and volumetric energy densities of 355.7 Wh kg ⁻¹ and 1017.4 Wh L ⁻¹ , respectively. Pouch‐cell demonstrations highlight the potential of SnSb for high‐energy density ASSLIB applications and establish reaction‐driven coupled transport–nanostructure evolution as an effective design principle for next‐generation ASSLIB anodes.