Stepwise Kinetics Promotion for High-Rate Aqueous Zn Metal Batteries

Metallic zinc anodes in aqueous zinc batteries suffer from uncontrolled dendrite growth and parasitic side reactions, leading to poor cycling stability, especially under high-rate and high-capacity conditions. Herein, we proposed a stepwise kinetics promotion process to achieve high-rate and durable Zn metal anodes, in which the desolvation, bulk transfer, and deposition steps of Zn²⁺ are systematically considered and synergistically regulated. Experimental and computational analyses reveal that N-methyl morpholine-N-oxide (NMMO) molecular regulator captures-rather than substitutes-coordinated water molecules in the Zn²⁺ solvation sheath, thereby suppressing Zn corrosion and hydrogen evolution without increasing desolvation barriers. Furthermore, the strong interaction between NMMO and free water reconstructs the hydrogen-bond network, creating an unimpeded proton-transport channel that accelerates Zn²⁺ bulk transfer. Additionally, the preferential adsorption of the NMMO molecule on non-(101) Zn facets promotes the selective exposure of highly active Zn (101) texture, boosting Zn deposition kinetics. Consequently, Zn||Zn symmetrical cell delivers exceptional lifespan- over 6100 h at 5 mA cm^-2 and 1300 h at 30 mA cm^-2-with low overpotentials. Notably, the Zn anodes still maintain stable cycling even at a 70% depth of discharge and ensure stable operation of full cells with a low negative/positive capacity ratio of 2.1.