Interface Optimization And Stability Of Zinc Anode For Aqueous Zinc-ion Batteries

Aqueous zinc-ion batteries（ZIBs）represent an efficient technology for large-scale energy storage due to their high specific capacity,high safety,environmental friendliness and low cost,and have been widely studied.So far,the cathode materials of ZIBs have made remarkable progress since the recent advances result in a significant improvement in terms of energy/power density.However,there are still challenges for the practical application of ZIBs,which principally originate from the limited cycle life and low zinc utilization of the Zn anode.To solve these issues,this thesis alleviates dendrite issues and irreversible side reactions by optimizing the interface between Zn anode and electrolyte,and thus improves the cycling stability of the Zn anodes.On this basis,the utilization of Zn anode is gradually improved.Finally,a high-performance aqueous zinc-ion battery was constructed.The main research results of this thesis are summarized as follows:（1）A surface microstructure was constructed to homogenize the Zn deposition.The grid microarray on the Zn electrode surface can enhance the electrode wettability and reduce the mass transfer resistance.Meanwhile,the numerous nanoparticles loaded on the electrode surface can act as stable nuclei to guide the smooth Zn deposition,and thus significantly reduce the dendrite size.The microstructure Zn electrode can cycle stably for more than2500 h at a current density of 10 m A cm^-2 and an areal capacity of 2 m A h cm^-2,with a cumulative plated capacity of 12.5 A h cm^-2,and its cycle life is orders of magnitude higher than that of bare Zn electrode.（2）A hydrated zinc phytate（PAZn）interlayer with high Zn²⁺conductivity was constructed to suppress the side reactions on the electrode surface.The PAZn interlayer can improve the interfacial stability of Zn electrode.Meanwhile,the charge shielding effect of crystal water in the interlayer can accelerate the Zn²⁺migration,thereby optimizing the Zn deposition kinetics.Benefiting from the above synergistic effects,the electrode can cycle for more than 1200 h at a current density of 10 m A cm^-2 and a zinc utilization of 17.1%,and can still cycle stably for more than 200 h even at a higher zinc utilization of 51.2%,which greatly extends the cycle life of the Zn electrode under high utilization conditions.（3）An aluminum-doped zinc oxide（AZO）multifunctional interlayer was constructed to optimize the reversibility and cycling stability of the Zn electrode,and further improve the utilization of Zn electrode.The AZO interlayer can ont only improve the corrosion resistance of the Zn electrode,but also the strong interaction between AZO and Zn²⁺is beneficial to promote the desolvation of hydrated Zn²⁺and regulate the Zn²⁺flux.In addition,the highly conductive AZO interlayer can effectively homogenize the interfacial electric field distribution,and smooth the Zn deposition.Benefiting from solving the irreversible side reactions and dendrite issues simultaneously,the cycling stability of the Zn electrode is significantly optimized,and its zinc utilization is greatly improved.The modified electrode can cycle stably for more than 200 h even at an ultra-high zinc utilization of 80%.Moreover,the H₂O molecule intercalated V₂O₅ nanowire cathode material was prepared to match the Zn anode with high utilization,and an aqueous zinc-ion battery with high zinc utilization was assembled.The device can cycle stably for more than 600 cycles with a capacity retention of 92.7%.Furthermore,a high-capacity pouch battery device was constructed based on the above system,proving its application prospect in high-performance commercial ZIBs.