Molecularly Engineered Circular Additive with Multi-site Desolvation for High-performance Zinc Ion Battery

Additive engineering can effectively relieve interface issues of aqueous zinc ion batteries (AZIBs), but most additives induce the sluggish interface kinetics and boosted polarization, especially at high current density and low temperature. Herein, the relationship between additive molecular structure and desolvation behaviour is built by utilizing a series of circular and linear sugar molecules as prototypes, which systematically reveals molecular size, steric configuration, electronic structure are design criteria for additives to achieve fast desolvation. As indicated by theoretical simulations and experiments, circular fructose (FRU) molecule with small size, quasi-planar adsorption configuration, and enhanced electron delocalization enables the compact electric double layer (EDL) with shorter Zn2+ diffusion path and lower activation energy via multi-site desolvation, thus obtaining the rapid interface kinetics and facilitating highly reversible zinc anode over a wide temperature range. Zn//Zn cell exhibits long cycle life exceeding 9500 hours, and Zn//NVO cell maintains 83.92% high-capacity retention after 2480 cycles under 6.95 μL mg-1 lean electrolyte and 11.94 mg cm-2 high loading.