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

• Silicon-graphite composite is prepared using different composition ratios.
• These composites are applied as electrode for Li-ion batteries.
• Effect of binder on electrochemical performance of composites is observed.
• PAA-assisted composite electrodes show improved electrochemical performance.

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.