Glycinamide modified polyacrylic acid as high-performance binder for silicon anodes in lithium-ion batteries

Silicon is one of the most promising anode materials for the next-generation high energy density lithium-ion batteries as its superior specific capacity and ultralow lithiation/delithiation voltage. Whereas, silicon suffers massive volume change during cycling, resulting in drastic pulverization of active material and iterative growth of solid electrolyte interphase, largely limiting their widely applications. To address the challenge, water-soluble glycinamide modified PAA (PAA-GA) is synthesized through a facile and low-cost coupling method as a polymer binder to assemble silicon anode for alleviating its huge volume change. The carboxyl and double amide groups of the PAA-GA can form hydrogen bonds with the hydration layer of silicon, and meanwhile the double amide groups of PAA-GA can form double hydrogen bonds via interchain cohesion. These strong supramolecular interactions are reversible and can recover the dissociated bonds more efficiently upon the elimination of the mechanical stress. The PAA-GA-based silicon electrodes exhibit excellent cycling stability and high coulombic efficiency, demonstrating the PAA-GA binder being great potential in fabricating high energy density silicon anodes for next-generation lithium-ion batteries.