Korean Journal of Chemical Engineering, Vol.40, No.3, 504-511, March, 2023
Dual-effect-assisted cross-linkable poly(N-allyl-vinylimidazolium)∙TFSI- as alternative electrode binder of lithium-ion battery
The increasing demand for electric vehicles, portable electronic devices, and energy storage devices has spurred interest in the development of high-capacity rechargeable lithium-ion batteries (LIBs). Polyionic liquids are used in LIB binders or electrolytes owing to their favorable physical properties. Chemical cross-linking of polymer binders has been proposed as an effective and simple method for increasing the volume of electrodes. The designed polymer binder offers high ion conductivity and robustness via an appropriate adjustment of the solid electrolyte interphase layer and chemical cross-linking during the electrochemical test. A cross-linked poly(N-allyl-vinyl imidazolium) (C-PAVIm)-based electrode can improve the cycle properties by decreasing the overpotential and allowing Li+ to flow at the interface between the active material and electrolyte. The surface of a C-PAVIm-based electrode is monitored via scanning electron microscopy and X-ray photoelectron spectroscopy. Electrochemical impedance spectroscopy results show that the C-PAVIm-based electrode after cycling exhibits a thinner solid electrolyte interphase layer and a lower diffusion resistance as compared with a poly(vinylidene fluoride) (PVDF)-based electrode. Therefore, the C-PAVIm-based electrode exhibits better charge-discharge stability than the PVDF-based electrode. These findings imply that polymer binders with appropriately designed chemical structures can improve the electrochemical performance of LIB systems.