a-MnO2 nanorod/onion-like carbon composite cathode material for aqueous zinc-ion battery

Abstract

Onion-like carbon (OLC) integrated a-MnO2 nanorods (a-MnO2/OLC) composite has been studied as a viable cathode material for potential development of high-performance zinc-ion batteries (ZIBs). XRD results revealed the tetragonal phase of the a-MnO2 materials, and the FE-SEM and HR-TEM images show nano-sized rod-shaped morphology with an average diameter of 30 nm. The BET surface area of the a-MnO2/OLC composite was almost 6 times (247.22 m2/g) higher than that of the pristine (42.48 m2/g) material and the thermogravimetric investigation was exposed 50% of MnO2 and 50% OLC is presented in the composite. The electrochemical performance of the cells was evaluated by galvanostatic cycling (GC), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using 1 M ZnSO4 plus 0.1 M MnSO4 additive as electrolyte and Zn foil as the anode. Cycling results indicate that a-MnO2/OLC composite exhibits a stable and high reversible capacity of 168 mAh g-1 (93% capacity retention) compared to the a-MnO2 material with a capacity of 104 mAh g-1 (81% capacity retention) after 100 cycles.