Modified Ion Migration via Multi-Ion Competitive Transportation for Stable Aqueous Zn Metal Batteries

The application of metal batteries is seriously affected by active ions transport and deposition stability during operation. This article takes water-based Zn metal electrodes as an example to analyze the factors that affect ion distribution and the impact of ion distribution on electrodeposition morphology through electrochemical model simulation calculation, in situ observation and electrochemical experiment: 1) high concentration will reduce the concentration polarization and the overpotential; 2) The passage of active ions through channels are facilitated by small anion (Cl^-) rather than bigger one (SO₄ ^2-), which means small deposition overpotential; 3) The transportability-reaction properties of cations (Zn²⁺, Li⁺, Na⁺ and H⁺) depends on their concentration, solvent coordination structure, and the energy changes during redox reactions. Based on the diffusion and reaction properties, a Li⁺ coupled Zn²⁺ electrolyte is designed to achieve the rapid transportation of doped ions to cover uneven growth sites and maintain a stable interface for the steady deposition of active Zn²⁺, guiding the interface design for high stability metal batteries in addition to the traditional addition of organic solvents.