Preparation of pectin-based dual-crosslinked network as a binder for high performance Si/C anode for LIBs

Abstract

The modification of pectin polysaccharide through grafting with polyacrylamide and crosslinking is newly proposed as a powerful candidate for a water-soluble binder of high-capacity Si anodes in lithium ion batteries. The grafting of pectin with polyacrylamide enhances adhesion in the electrode and contributes to the good wettability of the carbonate electrolyte. Herein, dual-crosslinking of pectin-g-polyacrylamide was achieved by the ionic crosslinking of pectin with divalent calcium ions and the chemical crosslinking of polyacrylamide with a bisacrylamide. As a result, the dual-crosslinked binder improves further the cycling performance of the Si/C composite anode with a 1.2 mg cm−2 loading, which retains a specific capacity of 729 mAh g−1 after 300 cycles. In contrast, the Si/C electrode containing dual-crosslinked alginate with polyacrylamide shows a specific capacity of 515 mAh g−1 after 300 cycles.