Conducting-polymer/iron-redox-couple composite cathodes for lithium secondary batteries

Physically or chemically attaching an Fe-III/Fe-II redox couple to the backbone of a conducting polymer leads to stabilization of the charge/discharge characteristics and higher electrode capacities. Composite cathodes made from LiFePO4 particles bound to polypyrrole show enhanced electrode capacities and better rate capabilities, as shown in the figure. Chemically attaching ferrocene to the pyrrole backbone not only stabilizes the charge-discharge curves but also leads to higher capacity.