The safety hazards and low Coulombic efficiency originating from the growth of lithium dendrites and decomposition of the electrolyte restrict the practical application of Li metal batteries (LMBs). Inspired by the low cost of low concentration electrolytes (LCEs) in industrial applications, dual‐salt LCEs employing 0.1 m Li difluorophosphate (LiDFP) and 0.4 m LiBOB/LiFSI/LiTFSI are proposed to construct a robust and conductive interphase on a Li metal anode. Compared with the conventional electrolyte using 1 m LiPF₆, the ionic conductivity of LCEs is reduced but the conductivity decrement of the separator immersed in LCEs is moderate, especially for the LiDFP–LiFSI and LiDFP–LiTFSI electrolytes. The accurate Coulombic efficiency (CE) of the Li||Cu cells increases from 83.3% (electrolyte using 1 m LiPF₆) to 97.6%, 94.5%, and 93.6% for LiDFP–LiBOB, LiDFP–LiFSI, and LiDFP–LiTFSI electrolytes, respectively. The capacity retention of Li||LiFePO₄ cells using the LiDFP–LiBOB electrolyte reaches 95.4% along with a CE over 99.8% after 300 cycles at a current density of 2.0 mA cm⁻² and the capacity reaches 103.7 mAh g⁻¹ at a current density of up to 16.0 mA cm⁻². This work provides a dual‐salt LCE for practical LMBs and presents a new perspective for the design of electrolytes for LMBs.

中文翻译：

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基于二氟磷酸锂的双盐低浓度锂金属电池电解质

由于锂树枝状晶体的生长和电解质的分解而产生的安全隐患和低库仑效率限制了锂金属电池（LMB）的实际应用。受工业应用中低浓度电解质（LCE）成本低廉的启发，建议采用0.1 m二氟磷酸锂（LiDFP）和0.4 m LiBOB / LiFSI / LiTFSI的双盐LCE在Li金属阳极上构建坚固而导电的界面。与使用1 m LiPF ₆的常规电解质相比，LCEs的离子电导率降低，但浸入LCEs的隔膜的电导率降幅适中，尤其是对于LiDFP–LiFSI和LiDFP–LiTFSI电解质而言。Li || Cu电池的精确库仑效率（CE）从83.3％（使用1 m LiPF _6的电解质）增加到LiDFP–LiBOB，LiDFP–LiFSI和LiDFP–LiTFSI电解质的97.6％，94.5％和93.6％。 ， 分别。李||的LiFePO的容量维持_4个使用LiDFP-LiBOB的电解质细胞以2.0毫安cm 2的电流密度达到具有CE超过300次循环后99.8％95.4沿％^-2和容量达到103.7毫安克^-1以电流密度高达16.0 mA cm ^-2。这项工作为实际的LMB提供了双盐LCE，并为LMB的电解质设计提供了新的视角。