Chemically welded dual-conductive micron-sized SiOx anodes enabled by a crosslinked binder for high-efficiency lean-electrolyte lithium storage

Micron-sized SiO x is a promising high-capacity anode for lithium-ion batteries, but its practical implementation remains limited by low initial Coulombic efficiency, sluggish kinetics, and rapid structural degradation. Here, we propose a synergistic modification strategy that integrates an interfacially bonded dual-conductive SiO x composite with a robust polymeric binder. High-energy co-milling of SiO x with electronic carbon and the ionic conductor Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 induces the formation of Si–C, Ti–C, and Si–O–Ti bonds, which interconnect the active and conductive phases into a continuous three-dimensional transport network while reducing direct exposure of SiO x to the electrolyte. To further stabilize the electrode architecture, this composite is coupled with a highly crosslinked sodium alginate–trimethylol melamine binder that exhibits superior thermal stability, electrolyte affinity, and mechanical strength compared to conventional binders. This binder plays a critical role in stabilizing mass-transport pathways by suppressing volume variations and promoting formation of a stable, LiF-rich solid electrolyte interphase. Benefiting from this dual-engineering design, the SiO x /C/LATP anode achieves an initial Coulombic efficiency of 76.2% at 0.1 A g −1 , a high capacity of nearly 901 mAh g −1 at 4.0 A g −1 , and exceptional capacity retention of 93.4% after 200 cycles at 1.0 A g −1 under lean electrolyte conditions, outperforming most reported SiO x -based systems. Full cells paired with NCM811 further exhibit impressive rate capability, prolonged cyclability, and high energy density, demonstrating the practical promise of this scalable approach. This work establishes a versatile design framework for enhancing the efficiency, kinetics, and durability of SiO x anodes, offering valuable guidance for both liquid- and solid-state battery applications.