Chemically and electrochemically prepared graphene/MnO2 nanocomposite electrodes for zinc primary cells: a comparative study

In this study, chemically and electrochemically derived graphenes (CG and EG) were synthesized to form manganese dioxide (alpha-MnO2)/graphene nanocomposite cathode material for zinc primary cell. The discharge capacity of prepared nanocomposites was studied using Swagelok-type cell setup, where alpha-MnO2/graphene was used as a cathode and zinc as an anode along with an electrolyte (ZnCl2). Electrical conductivity and discharge behaviors of the CG and EG samples were studied in detail. The EG sample showed a high discharge capacity of 337 mAh g(-1), whereas the CG sample showed a discharge capacity of 205 mAh g (-1). More importantly, the discharge capacity of the EG sample-based cathode was 64 % higher than that of the CG sample-based cathode. The above observation suggests that EG sample serves as an effective cathode material for zinc-based primary battery applications.