Study On Nickel Zinc Super Battery With Graphite Felt Three Dimensional Network Structure

To solve the zinc electrode deformation and zinc dendrite formation problems on the electrode during the charge and discharge cycles of nickel zinc battery,the chelated zinc with hydroxyl and amino groups was loaded on the treated graphite felt with rich oxygen groups.The interaction between zinc active material and polar group of graphite felt fiber was used to enhance the adsorption of zinc material on the support.The fiber orientation induces the growth orientation of zinc dendrite,and the three-dimensional space structure can accommodate the growth of zinc dendrite,which improves the performance of nickel zinc battery.The electrochemical activities of zinc oxide,zinc glycinate and zinc gluconate were compared by electrochemical three electrode system.The equilibrium potentials of the three materials were-1.603 V,-1.562 V and-1.61 V,respectively.The reduction peak current of zinc glycinate and zinc gluconate was larger in cyclic voltammetry curves,the oxidation peak current corresponding to zinc oxide material was larger than that of zinc glycinate and zinc gluconate.Zinc gluconate ligands have high steric hindrance,and the performance of nickel zinc batteries is lower than that of zinc glycinate and zinc oxide material.The graphite felt was pretreated with 30% hydrogen peroxide,muffle furnace heating and microwave method respectively.The number of oxygen-containing functional groups on the surface of graphite felt was increased after treatment.Zinc gluconate was loaded on 30% H2O2 treated graphite felt and it was assembled the nickel zinc battery,the voltage efficiency of the last cycle was 57% after 107 h cycle.Activated carbon and graphene were used as capacitor materials before and after treatment with 30% H2O2,which were loaded on graphite felt together with zinc oxide.The energy density of nickel zinc battery loaded with activated carbon was 127wh/kg,and that of graphene loaded on nickel zinc battery was 67wh/kg.After 200 charge and discharge cycles,the coulomb efficiency was more than 80%,while the coulomb efficiency of nickel zinc battery without super capacitor material is only 26.7%.The charging performance of nickel zinc battery battery loaded with hydrophilic capacitor material is better than that of nickel zinc battery loaded with hydrophobic material.