Reduced graphene oxide/Fe-phthalocyanine nanosphere cathodes for lithium-ion batteries

Organic–inorganic composites show great potential for organic rechargeable lithium-ion batteries. In this work, two-dimensional phthalocyanine molecules were converted into hybrid nanoparticles with a porous structure and bound to a conductive graphene layer to act as a cathode material. The conductivity of this reduced graphene oxide/Fe-phthalocyanine (rGO/FePc) composite is improved through good interfacial connections and internal polymerization. The FePc spheres were shaped with the assistance of Fe 3 O 4 and immobilized between the layers of reduced graphene oxide (rGO). The electrochemical properties of the organic–inorganic composites were investigated by testing in a lithium-ion cell. A high discharge capacity of 186 mAh g −1 was maintained after 100 cycles at 300 mA g −1 , which demonstrates a significant improvement in the cycle life compared to previous reports of phthalocyanine-based electrochemical energy storage behaviour.