Strategy for Using Electrolyte Additives to Regulate Zinc-Ion Battery Anode Interfaces via Tautomerism

The performance of zinc-ion batteries (ZIBs) is often hindered by issues such as dendrite formation, hydrogen evolution, and limited cycling stability. 1,3-Dihydroxyacetone (DHA) not only stabilizes the anode by modulating the anode/electrolyte interface (AEI) but also enhances the electrochemical performance of the battery through its spontaneous and reversible keto-enol tautomerization, reducing the concentration gradient on the anode surface. Using a combination of DFT calculations and experimental characterization, the regulation of the hydrated Zn²⁺ structure and its adsorption at AEI by this additive is investigated. Overall, incorporating DHA extends the cycling stability of Zn||Zn symmetric batteries to 400 h, even at a depth of discharge of 56.7% (DOD). Zn||VNNC full batteries exhibit stable cycling for 700 cycles at 5 A g^-1 with a low N/P ratio (2.69), while the performance of Zn||AC capacitors (ZICs) is significantly enhanced. This study evaluates the additive potential in ZIBs through the dynamic characteristics of molecular structures.