Binary transition metal oxides (BTMO) (Co-Zn, Co-Cu) synthesis and high supercapacitor performance

Binary transition metal oxides (BTMO) (Co-Zn, Co-Cu) on Ni foam are fabricated through a facile and cost efficient hydrothermal method. In the three-electrode system testing, CoO@ZnO shows the highest specific capacitance of 2.394 F/cm2 at a current density of 5 mA/cm2 as well as excellent cycling stability which remains 76.5% of initial capacitance after 1000 cycles. This study provides an important method for the synthesis of high performance BTMO for supercapacitors. •BTMO were fabricated through a facile hydrothermal method.•The highest specific capacitance of CoO@ZnO nanowires of 2.394 F/cm2 at 5 mA/cm2.•CoO@ZnO nanowires show excellent cycling stability.