Three-Dimensional Rigidity-Reinforced SiOx Anodes with Stabilized Performance Using an Aqueous Multicomponent Binder Technology

Abstract

Three-dimensional (3D) rigidity-reinforced SiOx anodes are prepared using the aqueous multicomponent binders to stabilize the performances of lithium-ion batteries. Considering an elastic skeleton, adhesiveness, electrolyte absorption, etc., four kinds of binders [polyacrylamide (PAM), poly(tetrafluoroethylene) (PTFE), carboxymethyl cellulose, and styrene butadiene rubber (SBR)] are selected to prepare aqueous multicomponent binders. The SiOx anodes with the binder PAM/SBR/PTFE (PSP) exhibit a 3D rigidity-reinforced structure, larger adhesive force, and moderate electrolyte adsorption capacity compared to other anodes with single and multicomponent binders. Specifically, the electrochemical performances of the SiOx anodes with the binder PSP663 are stabilized, and a retention capacity of 770 mAh g-1 at 500 mA g-1 after 300 cycles and a rate capacity of 993 mAh g-1 at 1200 mA g-1 are obtained. The enhanced performances are attributed to the good chemical stability of PTFE to protect SiOx particles from the electrolyte corrosion and to ensure electrode integrity. SBR acts as the binder backbone due to the strong adhesion force and specific three-dimensional structure. The rigidity of PAM limits the excessive expansion of SiOx particles well and shortens the ion migration. These results indicate that the 3D rigidity-reinforced SiOx anode with the aqueous binder PSP663 has promising prospects for practical application, and the results also provide a reference for solving the expansion problem of the silicon materials.