Facile Stabilization of Microsilicon Oxide Based Li-Ion Battery Anode Using Poly(vinylphosphonic acid)

While lithium-ion batteries (LIB) are utilized extensively, more desirable binders are also necessary to improve the performance of LIB. In this paper, poly(vinylphosphonic acid) (PVPA) was adopted as a binder for a microsilicon oxide (SiO)/graphite composite anode. PVPA (SiO/G-PVPA) based anodic half-cell exhibited improved cycle performance (650 mA h gC+SiO–1 for 200 cycles at 1000 mA g–1). On the other hand, the SiO electrode with poly(vinylidene fluoride) (PVDF) lost its capacity down to 150 mA h g–1 after 100 cycles. Moreover, PVPA binder achieved a high capacity of 500 mA h g–1 for 100 cycles with a SiO high-loading anodic (1.84 mg cm–2) anodic half-cell. This improvement was achieved due to the strong adhesion and stability of PVPA. Scanning electron microscope (SEM) observation showed that the PVPA binder inhibited the exfoliation of active materials from the substrate for 200 cycles. In addition, electrochemical impedance measurement showed that the resistance of the electrode–electrolyte interface was reduced dramatically in the presence of PVPA.