Zinc-nickel Battery Negative Electrode Active Material And Electrolyte

Zn-Ni battery is an ideal power source of electric vehicle et al because of its high theoretical capacity, low cost, abundant resource, no mercury and no cadmium. However, it is not fit for battery because discharge production of negative electrode is dissolved easily in potassium hydroxide electrolyte. The study objects of this paper included: ﹝inc negative electrodes prepared by zinc oxide , calcium zincate, compound of zinc oxide and barium hydroxide;(2)potassium carbonate, potassium fluoride and potassium hydroxide alkaline electrolyte. Electrochemical mechanism and electrochemical performance of negative electrodes were studied by X-ray diffraction, cyclic voltametry, Tafel Plot , A.C. Impedance, charge and discharge performance.The crystal structure of calcium zincate composed by ourselves was verified by X-ray diffraction. Compositions and quantitative change of active material in negative electrodes prepared by calcium zincate, compound of zinc oxide and barium hydroxide were analyzed by X-ray diffraction after they were cycled 10 and 50 times in potassium hydroxide alkaline electrolyte; potassium carbonate, potassium fluoride and potassium hydroxide alkaline electrolyte. Curves of cyclic voltametry and reversible intervals of cyclic volt-ampere were tested by Electrochemical Working Station. Standard electrode potentials and number of the reactive electrons of negative electrodes were calculated in reversible intervals. Tafel Plot and A.C. Impedance were tested. Linear intervals of super potential and current were tested. Numerical values of Tafel constant b and density of exchange current were calculated in linear intervals. Electrochemical resistances were compared by A.C. Impedance. Charge,IVABSTRACTdischarge and cyclic performance of negative electrodes were tested by laboratory cell technologies.The results of studies showed: dissolution of discharge production of negative electrodes prepared by calcium zincate and compound of zinc oxide and barium hydroxide were Slow down in electrolyte. Charge, discharge and cyclic performance of negative electrodes prepared by calcium zincate or compound of zinc oxide and barium hydroxide were better than negative electrode prepared by zinc oxide. In potassium carbonate, potassium fluoride and potassium hydroxide alkaline electrolyte, dissolution of zinc oxide was reduced and cyclic life of negative electrodes were prolonged.