“…To address this issue and improved on the electrochemical performance, mixed metal oxides, transition metal sulfides including both binary and ternary materials with stoichiometric composition have recently been investigated as novel pseudocapacitive materials for supercapacitors due to their outstanding electrochemical properties, rich redox reactions involving different ions, complex chemical compositions and their synergetic effects [13][14][15][16][17]. Compared to single and simple metal oxides, mixed metal oxides or sulfides exhibit variable oxidation state, high electrical conductivity due to lower activation energy for electron transfer between cations [18][19][20].…”