An Energy-Dissipative Sesbania Gum-Grafted Poly(acrylic acid) Binder for SiOx Anode in Li-Ion Batteries

Silicon oxide (SiOx) has emerged as one of the most promising anode materials for lithium-ion batteries due to its high theoretical capacity, ultralow lithiation/delithiation voltage, and abundant natural resource reserves. However, its severe volume expansion and insufficient cycling stability during lithiation–delithiation processes pose significant challenges to practical applications. Herein, an energy-dissipative sesbania gum-grafted-poly(acrylic acid) (SG-g-PAA) binder is fabricated via free-radical-initiated graft copolymerization for SiOx anodes. The SG-g-PAA binder rationally combines the intrinsic elasticity of the natural SG with the stiffness of PAA to construct a mechanically stable framework. The 3D network balances stiffness and elasticity, effectively accommodating the large volumetric changes while preserving electrode structural integrity during cycling. And the synergistic combination of covalent cross-links and dynamic hydrogen bonding further enhance the long-term cycling stability in SiOx anodes. With this binder, the SiOx electrode delivers a high specific capacity of 1134 mAh g–1 after 250 cycles at a current density of 400 mA g–1. The assembled SiOx@SG-g-PAA||NCM622 full cell showed an 88% capacity retention over 100 cycles at 0.3 C.