Micro Soluble Additives Regulate Interface Components to Assist High-Temperature Lithium Metal Batteries

Abstract

As the operating temperature increases, the electrode-electrolyte interface and electrolyte solvation structure of lithium metal batteries become increasingly unstable, which shortens battery life and may lead to safety concerns. In this study, we prepare a stable suspension electrolyte by incorporating a slightly soluble film-forming additive, lithium methoxide. Both calculations and experiments demonstrate that the introduction of lithium methoxide facilitates the preferential decomposition of anions while promoting stable interfaces (cathode and anode), thereby enhancing the high-temperature performance of lithium metal batteries. For Li/Li batteries utilizing the modified electrolytes, we observe excellent reversibility with a prolonged lifespan exceeding 250 h. At 70 °C, we achieve remarkable cycling stability (~82.5% over 200 cycles) and impressive rate performance in LCO/Li batteries using the modified electrolytes. Our advances shed light on an encouraging suspended electrolyte tactic for the Li-metal batteries confronted withstringent high-temperature challenges.

Keywords: Lithium metal battery；High-temperature electrolyte, Micro soluble additive