Investigation of morphological changes on nickel manganese oxide and their capacitance activity

Varied morphology of nickel manganese oxide (NiMn2O4) is synthesized using the hydrothermal method. The surface morphologies and structures of NiMn2O4 materials are examined by XRD, Raman spectroscopy, UV-vis, FESEM, and HRTEM. XPS is conducted to analyze surface elemental compositions of NiMn2O4. BET analysis is also conducted to measure the surface area and pore volume of the NiMn2O4. Different NiMn2O4 materials are coated on nickel foam electrode to test the capacitance activity from cyclic voltammetry and galvanostatic charge discharge techniques with 1.0 M KOH. Ethylene glycol assisted NiMn2O4 (eg-NiMn2O4) delivers the maximum capacitance is 469 F g(-1) at 1.0 A g(-1) current rate and 92.3 % capacity retention at 3000 cycles (current density of 10 A g(-1)). The resulting eg-NiMn2O4 proved to be advantageous over other synthesized CTAB assisted NiMn2O4 (ct-NiMn2O4) and p-NiMn2O4 (NiMn2O4 without capping agents) electrodes in terms of high specific capacity, superior cyclability, and good rate capability due to their structural changes and interconnected pores.

Automated summary

Varied morphologies of NiMn2O4 were synthesized using the hydrothermal method for capacitance activity testing. The ethylene glycol-assisted NiMn2O4 showed advantages in terms of high specific capacity, superior cyclability, and good rate capability.