Simple direct fabrication of manganese oxide 3-D electrodes on Ni foam via thermal decomposition of manganese Formate-Amine ink for supercapacitors

•A simple direct fabrication of 3-D electrodes was developed on Ni foam.•Ink of manganese formate, amine, and hexanol was prepared for deposit onto the Ni foam.•3-D electrodes were generated on Ni foam via immersion in the ink and calcination.•Large surface areas via small pores or high mass loading resulted in high specific capacitance.•Prepared 3-D electrodes showed good stability.