Stable Harsh-Temperature\nLithium Metal Batteries Enabled\nby Tailoring Solvation Structure in Ether Electrolytes

For\nlithium metal batteries (LMBs), the elevated operating\ntemperature\nresults in severe capacity fading and safety issues due to unstable\nelectrode–electrolyte interphases and electrolyte solvation\nstructures. Therefore, it is crucial to construct advanced electrolytes\ncapable of tolerating harsh environments to ensure stable LMBs. Here,\nwe proposed a stable localized high-concentration electrolyte (LHCE)\nby introducing the highly solvating power solvent diethylene glycol\ndimethyl ether (DGDME). Computational and experimental evidence discloses\nthat the original DGDME-LHCE shows favorable features for high-temperature\nLMBs, including high Li+-binding stability, electro-oxidation\nresistance, thermal stability, and nonflammability. The tailored solvated\nsheath structure achieves the preferred decomposition of anions, inducing\nthe stable (cathode and Li anode)/interphases simultaneously, which\nenables a homogeneous Li plating–stripping behavior on the\nanode side and a high-voltage tolerance on the cathode side. For the\nLi||Li cells coupled with DGDME-LHCE, they showcase outstanding reversibility\n(a long lifespan of exceeding 1900 h). We demonstrate exceptional\ncyclic stability (∼95.59%, 250 cycles), high Coulombic efficiency\n(>99.88%), and impressive high-voltage (4.5 V) and high-temperature\n(60 °C) performances in Li||NCM523 cells using DGDME-LHCE. Our\nadvances shed light on an encouraging ether electrolyte tactic for\nthe Li-metal batteries confronted with stringent high-temperature\nchallenges.