Ether is regarded as an exceptional solvent in liquid electrolytes for lithium (Li) metal batteries due to its outstanding compatibility with Li metal anode. Low salt concentration in ether-based electrolytes (LCEEs) is highly favorable to reducing the cost of future Li metal batteries. Nevertheless, LCEEs have been reported to exhibit poor anodic stability (as low as 4.0 V Li/Li), therefore considered unsuitable for practical batteries using LiNiMnCoO as cathodes and charge up to 4.4 V. Here, using 1.0 M lithium bis(fluorosulfonyl)imide (LiFSI) in 1,2-dimethoxyethane (DME) as the baseline, we demonstrate the intrinsic anodic stability window of LCEE to be above 4.5 V. We revealed the true failure mechanism of LCEE to be various electrochemical reactions with different working electrodes (WEs). We further provide electrolyte and electrode design rules to prevent LCEE decomposition, as well as electrode and packaging materials corrosion at high voltage. This study highlights the importance of previously overlooked battery component compatibility in electrolyte development and offers valuable insights into battery engineering considerations toward high-energy and cost-effective Li metal batteries.

中文翻译：

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重新评估锂金属电池的低浓度醚基电解质

由于与锂金属阳极具有出色的相容性，醚被认为是锂（Li）金属电池液体电解质中的特殊溶剂。醚基电解质（LCEE）中的低盐浓度非常有利于降低未来锂金属电池的成本。然而，据报道，LCEE 的阳极稳定性较差（低至 4.0 V Li/Li），因此被认为不适合使用 LiNiMnCoO 作为阴极并充电至 4.4 V 的实际电池。此处，使用 1.0 M 双（氟磺酰基）亚胺锂以 1,2-二甲氧基乙烷 (DME) 中的 LiFSI 为基准，我们证明了 LCEE 的固有阳极稳定性窗口高于 4.5 V。我们揭示了 LCEE 的真正失效机制是不同工作电极（WEs）的各种电化学反应。 ）。我们进一步提供电解质和电极设计规则，以防止 LCEE 分解以及电极和封装材料在高压下腐蚀。这项研究强调了以前在电解质开发中被忽视的电池组件兼容性的重要性，并为高能量和具有成本效益的锂金属电池的电池工程考虑因素提供了宝贵的见解。