Effect of polypyrrole on improving electrochemical performance of silicon based anode materials

Silicon and polypyrrole composites with different microstructures of polypyrrole were synthesized using high-energy mechanical milling. The nano-wires polypyrrole and micro-particles polypyrrole act as a matrix to hold the active silicon grains as they repeatedly alloy with lithium during the operation of a lithium ion battery. The composite containing 10 wt.% polypyrrole nano-wires exhibits a relative better reversibility and cycle life than bare silicon, while the silicon/micro-particles polypyrrole composite shows no improvement.

► Si/PPy composites for lithium ion battery have been synthesized.
► PPy of two microstructures acting as matrix have been synthesized and characterized.
► Two kinds of PPy show different effects on improving electrochemical performance.
► Si/nano-wires PPy shows an improved electrochemical performance.