Nickel-doped MnO₂ nanowires anchored onto reduced graphene oxide for rapid cycling cathode in lithium ion batteries

Nickel-doped MnO₂ nanowires were synthesized directly onto reduced graphene oxide (RGO) to generate a composite cathode material with improved high-rate cycling characteristics. The presence of RGO improves the electrochemical characteristics of the cathode in Li-ion half-cell architecture. Cyclic voltammetry, electrochemical impedance spectroscopy, and electrode cycling are confirm that RGO plays a major role in enhancing the ability of the Ni_xMn_(1-x)O₂ to reversibly intercalate lithium ions at 1C rate. The chronocoulometric response of the RGO-based electrode shows the improvements originate from faster reaction kinetics and transport of Li⁺ coupled with increased specific capacitance and Li⁺ adsorption.