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

Abstract

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.