Preparation And Electronical Performance Of Cobalt-based Double-metal Oxidde Materials

In this paper,cobalt-based bimetal oxide electrode materials with different morphologies were successfully prepared by simple hydrothermal and annealing combined with template method.The effects of the amount of precipitating agent,hydrothermal temperature and calcination temperature on the Zn Co₂O₄electrode material were investigated.The electrochemical performance of Zn Co₂O₄electrode material was improved by compounding with hydrothermal carbon substrate and controlling the amount of template agent.The effects of calcination temperature and different templating agents on Fe Co₂O₄electrode materials were also investigated.The composition and morphology of the materials were analyzed by XRD and SEM,etc;the electrochemical properties of the electrode materials were analyzed by CV,EIS and GCD,and so on.Zn Co₂O₄electrode material was prepared by hydrothermal and calcination combined with binder-free method.The effects of the amount of precipitant,hydrothermal temperature,and calcination temperature on cobalt-zinc electrode material were investigated.Based on the optimal reaction conditions,the composites were prepared with hydrothermal carbon-based materials.The electrochemical properties of the materials which are precomposited and composited were analyzed.The results show that the material combined with a thermal carbon material present good electrochemical performance,with a hydrothermal temperature of 140°C,a concentration of precipitant of 0.168 mol/L,and a calcination temperature of 250°C.At the current density is 1 A/g;the specific capacitance reaches 1050 F/g;at the current density is 10 A/g,the specific capacitance can reache 888F/g;even though the high current density of 10 A/g,the capacity retention rate reaches90.3%after 2000 cycles.The Zn Co₂O₄electrode material was prepared by the template method.The influence of the amount of template(CTAB,SDS,PVA and PVP)on the electrode material were discussed.Obviously,The templating agent effectively improve the electrochemical performance of the materials.Especially,morphology of material performance a lotus-like structure with uniform dispersion,when the amount of PVP is 14.28 g/L.At a current density of 1 A/g,the specific capacitance is as high as 1527 F/g;At a current density of 10 A/g,the capacity retention rate reached 86.0%after 2000 cycles.In addition,the positive electrode used this material and the negative electrode used activated carbon(AC)to assemble an asymmetric supercapacitor device.The device has a power density of 774.6 W/kg and an energy density of 69.2 Wh/kg.At a current density of 10 A/g,the capacity retention rate was 77.0%after 2000 cycles.The electrochemical performance of Fe Co₂O₄electrode materials was successfully improved,by adjusting the calcination temperature and adding template agents(CTAB,SDS and PVP).The results show that the capacities of the materials without template and PVP,SDS and CTAB are 677 F/g,1231 F/g,956 F/g and 1028 F/g,respectively,at a current density of 1 A/g.In addition,we used a material added with a PVP template as the positive electrode and activated carbon as the negative electrode to assemble the ASC device.The device has a power density of 775.4 W/kg and an energy density of 51.2Wh/kg.