Study on Capacitance Properties of Redox Ion Doped Zn-Based Electrode Materials

Metal oxide electrode materials have relatively high theoretical capacitance. However, structure, morphology and composition of this kind of materials have significant influence on electrochemical performance. Moreover, metal oxide electrode materials have problems of low power density and cyclic stability. In this work, Mo-doped hydroxide zinc carbonate material (Mo-HZC) is synthesized on foam Ni surface by hydrothermal method. This Mo-doping electrode exhibits typical pseudocapacitance. Specific capacitance of Mo-HZC in 1.0 mol L-1 KOH is 698.9 F g-1 (1.0 A g-1), which is 2.5 times that of the undoped sample. The maximum energy density and power density of Mo-HZC electrode are 32.1 WH kg-1 and 3.16 KW kg-1, respectively. Assembled Mo-HZC//AC capacitor exhibits a long-term cycling performance with remains 79.5% capacitance retention within 20 000 cycles at 1.0 A g-1.