Energy-landscape-tailored solvation switching dynamics enable stable lithium batteries

Abstract

Solvation structures play a crucial role in electrolyte design, yet traditional strategies have primarily emphasized static solvation configurations, overlooking the inherently dynamic nature of solvation processes at the electrode interface. This oversight critically limits electrolyte performance, particularly where dynamic interfacial solvation layers govern ion-flux uniformity and the stability of interphase formation. Here, we propose a dynamic design framework based on an energy-landscape-tailored solvation switching mechanism that prioritizes dynamic adaptability over static equilibrium, thereby addressing the longstanding challenge of optimizing solvation dynamics at the interface. To quantitatively assess these dynamics, we developed a solvation switching energy index (SSEI), which exhibits a strong correlation with interfacial electrochemical behavior. Combining machine-learning molecular dynamics (MLMD) simulations with femtosecond transient absorption spectroscopy (fs-TAS), we directly probe and elucidate real-time solvation switching phenomena. Energetically, we uncover a constitutive control mechanism that enhances solvation diversity in traditional strategies, and further propose a contextual control strategy that is distinct from conventional lithium-salt-concentration and molecular-polarity regulation for minimizing the energy barrier for solvation transitions. This contextual control fundamentally transforms intrinsically diluted electrolytes, enabling exceptional interfacial performance, including a Coulombic efficiency (CE) of 99.8% for lithium metal plating/stripping and the effective suppression of solvent co-intercalation in graphite electrodes. This work redefines solvation dynamics as a central pillar in electrolyte engineering, bridging dynamics insights and high-performance energy storage systems.