Quasi-Solid Electrolyte Interphase Boosting Charge and Mass Transfer for Dendrite-Free Zinc Battery

The practical applications of zinc metal batteries are plagued by the dendritic propagation of its metal anodes due to the limited transfer rate of charge and mass at the electrode/electrolyte interphase. To enhance the reversibility of Zn metal, a quasi-solid interphase composed by defective metal-organic framework (MOF) nanoparticles (D-UiO-66) and two kinds of zinc salts electrolytes is fabricated on the Zn surface served as a zinc ions reservoir. Particularly, anions in the aqueous electrolytes could be spontaneously anchored onto the Lewis acidic sites in defective MOF channels. With the synergistic effect between the MOF channels and the anchored anions, Zn2+ transport is prompted significantly. Simultaneously, such quasi-solid interphase boost charge and mass transfer of Zn2+, leading to a high zinc transference number, good ionic conductivity, and high Zn2+ concentration near the anode, which mitigates Zn dendrite growth obviously. Encouragingly, unprecedented average coulombic efficiency of 99.8% is achieved in the Zn||Cu cell with the proposed quasi-solid interphase. The cycling performance of D-UiO-66@Zn||MnO2 (similar to 92.9% capacity retention after 2000 cycles) and D-UiO-66@Zn||NH4V4O10 (similar to 84.0% capacity retention after 800 cycles) prove the feasibility of the quasi-solid interphase.