In situ cross linkable random copolymer containing triethoxyvinylsilane as a novel polymeric binder for high performance of Li batteries

Abstract

The electro chemical performance of Li ion battery (LIB) can be highly tuned by various factors which include morphology of anode material, nature of electrolyte and binding material, percentage of conducting materials etc. Among them, binding material have been attracted by researchers over decades, which results in the introduction of different polymeric binder, originated from nature, such as poly acrylic acid, carboxy methyl cellulose, alginic acid etc. for Si anode of LIBs. Recently several synthetic and structural modifications of these conventional polymeric binders, for example, random co polymer of polyacrylic acid with vinyl alcohol, porous scaffold of CMC, etc. has been developed by many researchers. However, the challenges of further development of Li ion rechargeable batteries still exists because of some unique property possessed by Li batteries, such as high energy density, high specific capacity and light weight to carry. Inspired from these advantages of LIBs, here in, we introduce a novel polymeric binder for Si anodes in LIB as an effort to improve the columbic efficiency and cycle durability of LIBs. We report a novel random copolymer, poly(tert-butyl acrylate-co-triethoxyvinylsilane) as an efficient binder with high ICE of 91% for LIBs. The binder form in situ cross linking by the removal of protective tert-butyl groups, demonstrated by FT-IR, helps to minimize the pulverization of Si nano particle in the anode. Moreover, the Silane group in the polymer exhibits high adhesive property with the electrode surface. In this present work we tried to find the optimum percentage of triethoxyvinylsilane in the random co polymer by analyzing the electro-chemical-mechanical properties of series of synthesized random copolymer.