Uncovering the Interaction Nature of Solvation Shell for Transition‐Metal‐Based Aqueous Batteries

ABSTRACT Transition‐metal‐based aqueous batteries, particularly iron and zinc‐based systems, have emerged as promising candidates for energy storage technologies. Considerable efforts have therefore been devoted to regulating solvation structures, leveraging the active electronic orbitals of zinc and iron cations. However, the interaction nature between the centric cation and its solvation shell remains insufficiently clarified, necessitating a deeper understanding of the structural and energetic chemistries that govern solvation behavior. In this work, we conduct a comprehensive multiscale theoretical investigation to unveil the key factors dictating solvation interactions. In the structural perspective, quantum–chemical analyses resolve the evolution of solvation clusters and electronic configurations, identifying geometric parameters and orbital features. Energetically, decomposition analyses quantitatively reveal the fundamental interactions between the cation and solvation shell, clarifying the contributions of varied energy forms. Furthermore, the field‐dependent reorganization of solvation structures is systematically demonstrated, offering insights into solvation behavior under operational conditions. Representative ligands are then employed to illustrate the mechanism of solvation regulation. Overall, this study uncovers the structural and energetic mechanism of solvation interactions, providing a fundamental basis for rational solvation engineering in next‐generation transition metal‐based aqueous batteries.