A\nModified Natural Polysaccharide as a High-Performance\nBinder for Silicon Anodes in Lithium-Ion Batteries

Abstract

A modified\nnatural polysaccharide (carboxymethylated gellan gum)\nis investigated as a water-soluble high-performance binder for silicon\nanodes in lithium-ion batteries to improve poor cycle life and fast\ncapacity fade of silicon anodes due to dramatic volume expansion during\nlithiation/delithiation process. The numberof carboxyl and acetyl\ngroups distributed homogeneously in the modified polysaccharide polymer\nchain can form strong hydrogen bonds with the surface of Si particle\nand copper current collector, thus effectively restricting the volume\nchange of silicon and maintaining electronic integrity of Si electrodes\nduring repeated charge/discharge cycles. As a result, Si anodes with\ncarboxymethylated natural polysaccharide polymer present high capacity\nperformance, excellent rate capability, and stable cycling.