Synthesis,Characterization And Properties Of Cathodic Nano-Co-based Active/Catalytic Materials For Hybrid Zinc Batteries

The hybrid zinc-air/metal oxide battery with the advantages of high energy density,high power density,high and stable discharge platform,wide application range and environmental friendliness,and is an important technical direction for efficient energy conversion and storage.However,the current research on the hybrid zinc-air/metal oxide battery is still in the preliminary exploration stage.It is still a huge challenge to solve the problem of low ORR/OER activity of the catalyst,short life and polarization of the battery.In view of the existing problems of the hybrid zinc-air/metal oxide battery,this paper mainly studies the cathode catalyst and improves the anode current collector.A hybrid zinc-air/metal oxide battery system was constructed by using Co₃O₄ nanomaterial directly grown on foamed nickel as cathode active material.Co₃O₄@rGO composite nanomaterial was prepared as battery cathode active material.A new Co_1.21Ni_1.79O₄ nanomaterial catalyst was synthesized to explore the electrochemical performance of the battery system.The hybrid zinc-air/metal oxide battery system was successfully constructed by using foamed nickel with a shape-controllable Co₃O₄ as the cathode.The battery charge and discharge test results show that Co₃O₄ OPNWs hybrid zinc-based battery can stably carry out2200 charge and discharge cycles,the highest coulombic efficiency can reaches 92.8%,the voltage efficiency is up to 88%,the discharge voltage is kept at 1.65V,and the charge-discharge voltage gap can be stably maintained at about 0.3V when charged at a constant current of 25mA for 8min,standing for 5min and discharged over a constant 100?load to 0.7 V cutoff.The hybrid zinc-based battery is composed of a Zn-Co₃O₄ battery and a Zn-air battery,and the ORR/OER reaction of the Zn-air battery and the redox reaction of the cobalt oxide in the Zn-Co₃O₄ battery occur simultaneously.In the process of charging and discharging,only a high discharge voltage platform appears in the battery,which ensures that the battery can be stably discharged without large voltage fluctuations.Co₃O₄ was supported on foamed nickel with rGO on the surface to obtain Co₃O₄@rGO composite as cathode catalyst.It was found that when the battery was tested for charge and discharge cycle,the battery could run stably for 600 cycles,and the coulombic efficiency of the battery is in the range of 82%to 85%,the discharge voltage platform is stable at about1.65 V.When the discharge rate test was performed,the average discharge voltage was not attenuated when the discharge rate was increased from 1 C to nearly 5 C,and the Coulomb efficiency is above 86%.The cathode active material of Co_1.21Ni_1.79O₄ OPNNs was successfully prepared.Cyclic voltammetry and polarization curves show that Co_1.21Ni_1.79O₄ OPNNs has better ORR/OER bifunctional catalytic activity,which has a significant improvement on the coulombic efficiency,discharge voltage and cycle life of the battery.The Co_1.21Ni_1.79O₄ OPNNs battery was able to operate stably for 2590 cycles,the average discharge voltage was 1.69 V,and the Coulomb efficiency was 96.1%when charged with a constant current of 50 mA for 8 min,open for 5 min,and discharged over 100?constant resistance to 0.9 V cut-off...