The development of nonflammable electrolytes can boost energy density and battery safety, especially for layered metal oxide cathodes operating at high voltage. However, most nonflammable electrolytes are designed in a high concentration for compatibility with graphite electrodes and/or less decomposition. Herein, we introduced a solvation structure-mediated model to develop a nonflammable electrolyte based on trimethyl phosphate (TMP) solvent at a normal concentration. This advancement allows the graphite || lithium cobalt oxide full cell to operate at 4.5 V, delivering high energy density and also exhibiting a nonflammable feature. This achievement is realized using previously unreported components, including carbonate solvent, ethylene sulfate (DTD) additives, and conventional LiPF₆ salt. We analyzed the molecular behaviors of each electrolyte composition and also uncovered the unreported impact of DTD, highlighting its prerequisite conditions for effectively weakening the Li⁺-TMP interactions. This bottom-up design strategy offers a fresh perspective on regulating solvation structures and electrolyte formulations.

中文翻译：

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溶剂化化学介导的不易燃电解质用于高压锂离子电池

不易燃电解质的开发可以提高能量密度和电池安全性，特别是对于在高电压下工作的层状金属氧化物阴极。然而，大多数不可燃电解质均设计为高浓度，以便与石墨电极兼容和/或减少分解。在此，我们引入了溶剂化结构介导的模型来开发基于正常浓度的磷酸三甲酯（TMP）溶剂的不可燃电解质。这一进步使得石墨||钴酸锂全电池工作电压为 4.5 V，具有高能量密度，并且具有不易燃的特性。这一成就是使用以前未报道的成分实现的，包括碳酸酯溶剂、硫酸乙烯酯（DTD）添加剂和传统的LiPF ₆盐。我们分析了每种电解质成分的分子行为，并揭示了 DTD 未报道的影响，强调了其有效削弱 Li ⁺ -TMP 相互作用的先决条件。这种自下而上的设计策略为调节溶剂化结构和电解质配方提供了新的视角。