Water-based binder with easy reuse characteristics for silicon/graphite anodes in lithium-ion batteries

Abstract

A new binder, poly(2-propenoic acid, 2-methyl-, 3-[(2-aminoethyl) amino]-2-hydroxypropyl ester) (P-HAEAPMA), is synthesized and applied to silicon/graphite (Si/graphite) anodes in lithium-ion batteries. The Si/graphite anode with the binder exhibits good electrochemical stability. Furthermore, the materials on the discarded Si/graphite/P-HAEAPMA electrode can be recycled for use based on water because the P-HAEAPMA binder is easily soluble in water. The discharge capacity and capacity retention rate of the electrode with reused materials are slightly lower than those of the original Si/graphite/P-HAEAPMA electrode. The binder is rich in polar amino and hydroxyl groups, which not only helps to form strong adhesion between the electrode active material and copper foil but also promotes the transport of Li ions. The electrochemical performance of the electrode with the P-HAEAPMA binder is significantly enhanced compared with that of the electrode with the traditional PVDF binder or water-based LA133 binder. After 305 cycles, a specific capacity of 485.0 mA h g−1 and a capacity retention rate of 74.8% are achieved for the Si/graphite/P-HAEAPMA electrode. A binder, poly(2-propenoic acid, 2-methyl-, 3-[(2-aminoethyl) amino]-2-hydroxypropyl ester) (P-HAEAPMA), is synthesized and applied to silicon/graphite anodes in lithium-ion batteries, which exhibits good electrochemical stability. After 305 cycles, a specific capacity of 485.0 mA h g−1 and a capacity retention rate of 74.8% are achieved. Moreover, the discarded electrode with P-HAEAPMA binder can be reused just based on water because the P-HAEAPMA binder is easily soluble in water, and the electrochemical properties of the electrode with reused materials are slightly lower than those of the original electrode.