Modulating Zincophile Property and Solvation Structure via Molecular Isomerism Engineering for Enhanced Zn Anode Stabilization

Abstract In recent years, electrolyte additives with polar functional groups are widely adopted to stabilize zinc anodes, yet the isomerization effect on performance enhancement remains underexplored. This work investigates three cyclohexanedione (CYC) isomers—differing in carbonyl group positions—as additives to improve zinc anode performance. Theoretical and experimental analyses reveal that 1,2‐cyclohexanedione exhibits the strongest zincophile characteristics. It effectively promotes uniform Zn ² ⁺ deposition and suppresses dendrite growth via parallel adsorption on the zinc surface. Moreover, 1,2‐CYC optimally modulates the Zn ² ⁺ solvation structure, weakening water interaction and suppressing hydrogen evolution. Its lowest desolvation energy barrier facilitates water removal from the [Zn(H ₂ O) _5−x (1,2‐CYC)] ² ⁺ solvation cluster, enabling smooth Zn plating/stripping and enhanced rate capability and cycling life. As a result, the Zn||Zn symmetric cell with ZnSO ₄ + 1,2‐CYC electrolyte achieves exceptional cyclability over 5600 h at 1 mA cm ⁻² and 1 mAh cm ⁻² , far outperforming the blank electrolyte. The Zn||Cu half‐cell also attains an average Coulombic efficiency of 99.6%. In addition, the Zn||MnO ₂ full battery with 1,2‐CYC maintains 81.7% capacity after 5000 cycles at 2 A g ⁻¹ . This study provides new insights into the role of functional group isomerization in stabilizing zinc anodes, offering guidance for additive design in AZIBs.