Cyanoethyl-guar gum as an effective polymer binder for lithium titanate electrode of the lithium-ion battery

Abstract

Unlike high-capacity silicon active materials, lithium titanate Li4Ti5O12 (LTO) as an anode material in lithium-ion battery shows almost no volume change during the charge/discharge processes. This fact rather neglects the importance of binder materials for the LTO electrode. A few research efforts indicate that a polymer binder aiding rapid ion or electron transfer is suitable for the LTO electrode. In this study, the synergetic effect between branched guar gum polysaccharide and polar nitrile groups was thoroughly investigated as a promising binder candidate for the LTO electrode. The cyanoethyl-guar gum binder synthesized by a straightforward cyanoethylation of guar gum with acrylonitrile leads to lower resistance on lithium-ion transport and electrolyte penetration due to the strongly polar nitrile groups. Compared to the pristine guar gum binder-based LTO electrode, therefore, the LTO electrode containing the cyanoethyl-guar gum binder exhibits superior rate performance with improved kinetics.