Regulating the plating process of zinc with highly efficient additive for long-life zinc anode

The Zn-ion batteries (ZIBs) are considered as one of the most compelling candidates for large-scale energy storage due to their high capacity, cost-effectiveness, high output potential, safety, and eco-friendliness. However, the application of ZIBs is being seriously hindered by the dendritic formation on Zn electrode surfaces, which always leads batteries to circuit-short and failure. We report a discovery regarding the use of polyvinylpyrrolidone (PVP), a non-ionic polymer, as a highly efficient electrolyte additive to induce uniform Zn plating. Various characterizations reveal that PVP molecules are electrostatically adsorbed on zinc protrusions during zinc ion plating, inhibiting the development of zinc protrusions and guiding uniform plating of Zn2+. The Zn anode using PVP-additive electrolyte has a long plating/stripping cycle life of 1000 h at a current density of 0.5 mA cm−2. When coupled with a MnO2 cathode, the full cell of Zn–MnO2 with PVP-additive electrolyte achieves boosted stability (89.1% capacity retention after 500 cycles) than that with normal electrolyte (30.1% capacity retention after 158 cycles). The results of the study suggest new ideas for inexpensive and efficient electrolyte engineering strategies for high-performance ZIBs.