Lithium Acetylacetonate Mediated Multidimensional Optimization for Reversible Zn Anodes

Aqueous zinc-ion batteries (AZIBs) are promising for large-scale energy storage owing to their high safety, yet their practical application is hindered by uncontrollable zinc dendrite growth, interfacial side reactions, and poor deposition reversibility of zinc anodes. Herein, a multifunctional electrolyte additive, lithium acetylacetonate (LA), which integrates polar groups, a conjugated structure, and inert cations, is proposed to address these challenges. LA reconstructs the Zn²⁺ solvation structure and disrupts the hydrogen-bonding network of water to suppress side reactions, exhibits selective adsorption on the Zn (101) plane to induce ordered crystal texture and inhibit dendrites, and modulates interfacial ion dynamics to promote uniform Zn deposition. Benefiting from this multi-dimensional optimization, the Zn//Cu half batteries deliver an ultra-high average coulombic efficiency of 99.97% over 4000 cycles, Zn//Zn symmetric batteries maintain stable cycling for over 1500 h at 5 mA·cm^-2 and 5 mAh·cm^-2, and Zn//NH₄V₄O₁₀ full batteries retain 83% of the initial capacity after 10,000 cycles at 5 A·g^-1. The universality of this molecular design strategy is further verified by analogous performance improvements of other metal acetylacetonate compounds with similar structural characteristics. This work provides a practical solution for boosting the long-term cycling stability of AZIBs and establishes a new paradigm for the rational design of high-performance electrolyte additives for aqueous multivalent metal batteries.