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.