Synthesis of cobalt oxide-reduced graphene nanocomposite and its enhanced electrochemical properties as negative material for alkaline secondary battery

摘要

A potential negative electrode material Co_3O_4@rGO is synthesized via a facile reflux condensation route. The electrochemical performances of Co_3O_4@rGO composite for alkaline rechargeable Ni/Co batteries have been systemically investigated for the first time. The reduced-graphene can remarkably enhance the electrochemical activity of Co_3O_4 materials, leading to a notable improvement of discharge capacity, cycle stability and rate capability. Interestingly, the maximum discharge capacity of Co3O_4@rGO-20 (additive amount of GO is 20 mg) electrode can reach 511.4 mAh g~(-1) with the capacity retention of 89.1% after 100 cycles at a discharge current of 100 mA g~(-1). A properly electrochemical reaction mechanism of Co_3O_4@rGO electrode is also constructed in detail.