Data-Assisted Design of Temperature-Resistant Weakly Solvating Electrolyte for All-Climate 500 Wh/kg Lithium-Metal Batteries.

Abstract

Temperature-resistant weakly solvating electrolytes (TRWSEs) are indispensable for lithium-metal batteries with ultrahigh energy density (≥450 Wh kg^-1) and excellent temperature adaptability (±70 °C). However, how to design ideal TRWSEs efficiently and decipher their evolution at different temperatures is still a great challenge. Herein, via a data-driven strategy, a TRWSE with a melting point as low as -136 °C was elaborately designed. More importantly, the evolution of the TRWSE from intrinsic solvation structures to interphase constructions and to lithium-metal deposition at different temperatures was investigated. Intriguingly, the anion-rich solvation structures in this TRWSE, the anion-derived electrolyte-electrode interphases, and deposited lithium are all temperature-insensitive, especially at low temperatures. Consequently, lithium dendrites are effectively suppressed even at -30 °C with a high Coulombic efficiency of 98.2%. NCM811||Li cells exhibit highly enhanced cycling stability with a capacity retention of almost 100% after 300 cycles at -30 °C. Moreover, 8.5 Ah pouch cells, with a high energy density of 507 Wh kg^-1 and an ultrawide operating temperature of 140 °C, still deliver a capacity retention of 92.3% at temperatures as low as -70 °C, which can discharge even at -110 °C, demonstrating their huge potential at ultralow temperatures.