LAUSR

Abstract A simple and inexpensive thermal pyrolysis method was used at the laboratory-scale to produce a high charge-storage Mn/Co-oxide electrode for hybrid supercapacitors. The material was investigated using galvanostatic charge-discharge (GCD), SEM, EDX, XPS and XRD. The Mn/Co-oxide exhibited a highly porous and intricate microstructure which allowed for high charge storage (capacitance). NaOH, LiOH, NaClO 4 and LiClO 4 electrolytes were employed and it was concluded that the pH, the type of anion and the size of cation played a large role in the resulting charge storage capability of the material. The highest capacitance of 4500 ± 60 mF cm −2 (1.38 mAh cm −2 ) was observed in 1.0 M LiOH at a current density of 0.4 mA cm −2 . The high apparent capacitance was due to intercalation of cations (Na + or Li + ) into the crystalline structure of the Mn 0.5 Co 0.5 -oxide phase, rendering the electrochemical behavior of the metal-oxide closer to that of Li-ion battery electrodes than to pure supercapacitors.