Electrochemically Synthesized Polypyrrole/Graphene Composite Film for Lithium Batteries

A polypyrrole/reduced graphene oxide (PPy/r‐GO) composite film is prepared by inducing electrochemical reduction of graphene oxide incorporated into PPy as the dopant. This film has a wrinkled surface morphology with a porous structure as revealed by scanning electron microscopy. Its porous structure is attributed to the physical nature of the GO sheets, providing a templating effect during PPy deposition. This PPy/r‐GO composite is characterized using in‐situ UV–visible spectroelectrochemistry as well as Raman and Fourier‐transform IR spectroscopy. The PPy/r‐GO material shows greatly improved electrochemical properties, i.e., a high rate capability and excellent cycling stability when used as a cathode material in a lithium ion battery. It also delivers a large reversible capacity when used as an anode material, and this is mainly attributed to the reduced graphene oxide (r‐GO) component.