Incorporation of aniline tetramer into alginate-grafted-polyacrylamide as polymeric binder for high-capacity silicon/graphite anodes

Abstract

• Water-soluble copolymer binder with conductive aniline-oligomers is synthesized. • Alg- g -PAMAT binders exhibit stable cyclic capacity due to their good conductivity. • The balance between adhesion and conductivity is determined on Alg- g -PAMAT binder. • An optimized Alg- g -PAMAT binder helps to deliver a high capacity of 701.2 mAh g −1 . Progress in the performance of high-capacity silicon anodes has been made with a variety of material designs. In this study, a new design on polymeric binder is proposed for the high-capacity anodes. The effective addition of conductive aniline oligomers to adhesive alginate- graft -polyacrylamide binder improves the performance of the silicon/graphite composite electrodes. To do this, three-step in situ polymerization is adopted to synthesize adhesive and conductive alginate- graft -poly(acrylamide- co -acrylamide aniline tetramer). A small amount of aniline tetramer added to the binder, of 1.25 wt%, is enough to enhance electronic and ionic transport through the silicon-based anode, while maintaining electrode adhesion. Consequently, the silicon/graphite electrode containing the alginate- graft -poly(acrylamide- co -acrylamide aniline tetramer) binder shows 701.2 mAh g −1 after 200 cycles with excellent cyclic stability. This is significantly greater performance than that of the commercial graphite electrodes.