Performance of nickel-zinc battery with ZnO/activated carbon/3D network carbon felt as zinc negative electrode

The formation of negative zinc dendrite and the deformation of zinc electrode are the important factors affecting nickel-zinc battery life. In this study, three-dimensional (3D) network carbon felt via microwave oxidation was used as ZnO support and filled with 30% H2O2-oxidised activated carbon to improve the performance of the battery. The energy density and power density of the nickel-zinc battery reached 81.8 and 181.7 Wh kg(-1), respectively, at the first cycle of the charge and discharge. The coulomb efficiency and voltage efficiency of the battery were respectively 85% and 65.5% at the 921st cycle. The coulomb efficiency and voltage efficiency of the battery filled with 30% H2O2-oxidised activated carbon were respectively increased by 0.8% and 2.6% compared with those of the nickel-zinc battery filled with activated carbon, and by 31.2% and 6.9% compared with those of the nickel-zinc battery without the activated carbon. The adhesion between carbon felt and zinc was strengthened by polar groups, and the specific capacitance and hydrophilicity of zinc electrode were improved by filling the zinc electrode with 30% H2O2-oxidised activated carbon. Moreover, the hydrophilicity of carbon felt support and activated carbon capacitor material can promote the penetration and diffusion of electrolyte in the electrode and help eliminate zinc dendrite. The carbon felt electrode has the flexibility to avoid deformation of zinc electrode. The cycle stability of the battery was considerably improved by 935 times. Graphic abstract