Effect of binder and composition ratio on electrochemical performance of silicon/graphite composite battery electrode

A comparative study was conducted to examine the effect of two different polymer binders and composition ratio of active material on electrochemical performance of silicon-graphite (Si-Gr) composite electrode in rechargeable lithium-ion batteries (LIBs). Polyacrylic acid (PAA) and polyvinylidene fluoride (PVDF) were utilized as binders for composite electrode that was fabricated using Si powder, graphite and super P black (SPB) by varying composition ratios of active material. The electrochemical performance was investigated by galvanostatic charge/discharge tests at room temperature. The results revealed that composite electrode fabricated with PAA binder using maximum contents of Si powder (20 wt%) showed high specific capacity around 1000 mAh g(-1) with excellent capacity retention. The enhanced electrochemical performance can be attributed to high mechanical strength and adhesive capability provided by PAA binder to composite electrode. (C) 2014 Elsevier B.V. All rights reserved.