Anion-Modulated Solvation Sheath and Electric Double Layer Enabling Lithium-Ion Storage From −60 to 80 °C

Abstract

Current lithium batteries experience significant performance degradation under extreme temperature conditions, both high and low. Traditional wide-temperature electrolyte designs typically addressed these challenges by manipulating the solvation sheath and selecting solvents with extreme melting/boiling points. However, these solvent-mediated solutions, while effective at one temperature extreme, invariably fail at the opposite end due to the inherent difficulties in maintaining solvent stability across wide temperatures. Herein, we report the use of the main lithium salt to simultaneously address interfacial challenges at both extremely high and low temperatures. This approach is different from the conventional solvent-mediated strategies. As a proof of concept, we utilized lithium nitrate (LiNO₃) to establish an anion-controlled solvation structure and electric double layer. The formulated electrolytes exhibited remarkable performance across temperature extremes, retaining 56.1% capacity at −60 °C and sustaining 400 stable cycles at 80 °C. In contrast, electrolytes based on current solvent-mediated strategies failed to operate at −60 °C and could not exceed 50 cycles at 80 °C. By shifting the focus to the main salt rather than the solvent, our work offers the possibility of addressing the enduring challenges of electrolyte stability across a broad temperature range.