Lithium (Li) metal batteries (LMBs) with nickel (Ni)‐rich layered oxide cathodes exhibit twice the energy density of conventional Li‐ion batteries. However, their lifespan is limited by severe side reactions caused by high electrode reactivity. Fluorinated solvent‐based electrolytes can address this challenge, but they pose environmental and biological hazards. This work reports on the molecular engineering of fluorine (F)‐free ethers to mitigate electrode surface reactivity in high‐voltage Ni‐rich LMBs. By merely extending the alkyl chains of traditional ethers, we effectively reduce the catalytic reactivity of the cathode towards the electrolyte at high voltages, which suppresses the oxidation decomposition of the electrolyte, microstructural defects and rock‐salt phase formation in the cathode, and gas release issues. The high‐voltage Ni‐rich NCM811‐Li battery delivers capacity retention of 80% after 250 cycles with a high Coulombic efficiency of 99.85%, even superior to that in carbonate electrolytes. Additionally, this strategy facilitates passivation of the Li anode by forming a robust solid‐electrolyte interphase, boosting the Li reversibility to 99.11% with a cycling life of 350 cycles, which outperforms conventional F‐free ether electrolytes. Consequently, the lifespan of practical LMBs has been prolonged by over 100% and 500% compared to those in conventional carbonate‐ and ether‐based electrolytes, respectively.

中文翻译：

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非氟化醚可减轻高压 NCM811-Li 电池中的电极表面反应性

具有富镍 (Ni) 层状氧化物阴极的锂 (Li) 金属电池 (LMB) 的能量密度是传统锂离子电池的两倍。然而，它们的寿命受到高电极反应性引起的严重副反应的限制。氟化溶剂基电解质可以解决这一挑战，但它们会造成环境和生物危害。这项工作报告了无氟醚的分子工程，以减轻高压富镍 LMB 中的电极表面反应性。通过简单地延长传统醚类的烷基链，我们有效地降低了阴极在高电压下对电解液的催化反应活性，从而抑制了电解液的氧化分解、阴极的微观结构缺陷和岩盐相的形成以及气体释放问题。高电压富镍NCM811-Li电池在250次循环后容量保持率为80%，库仑效率高达99.85%，甚至优于碳酸盐电解质。此外，该策略通过形成坚固的固体电解质界面来促进锂阳极的钝化，将锂的可逆性提高到99.11%，循环寿命为350次，优于传统的无氟醚电解质。因此，与传统的碳酸酯基电解质和醚基电解质相比，实际 LMB 的寿命分别延长了 100% 和 500% 以上。