The electrochemical and thermal stabilities of commonly used LiPF₆/organic carbonate-based electrolytes are still a bottleneck for the development of high energy density lithium-ion batteries (LIBs) operating at elevated cell voltage and elevated temperature. The use of intrinsic electrochemically stable electrolyte solvents, e.g. sulfones or dinitriles, has been reported as one approach to enable high voltage LIBs. However, the major challenge of these solvents is related to their poor reductive stability and lack of solid electrolyte interphase (SEI)-forming ability on the graphite electrode. Here, 3-methyl-1,4,2-dioxazol-5-one (MDO) is synthesized and investigated as new highly effective SEI-forming electrolyte additive which can sufficiently suppress electrolyte reduction and graphite exfoliation in propylene carbonate (PC)-based electrolytes. With the addition of only 2 wt % MDO, LiNi_0.5Mn_0.3Co_0.2O₂ (NMC532)/graphite full cells containing a 1 M LiPF₆ in PC electrolyte reach a cycle life of more than 450 cycles while still having a capacity retention of 80%. In addition, MDO has proven to be oxidatively stable until potentials as high as 5.3 V vs Li/Li⁺. Further development of MDO and its derivatives as electrolyte additives is a step forward to high voltage stable electrolyte formulations based on alternative electrolyte solvents and high energy density LIBs.

中文翻译：

---

高压锂离子电池的高效固体电解质相间形成电解质添加剂

常用LiPF ₆的电化学和热稳定性基于有机碳酸酯的电解质仍然是开发在较高的电池电压和较高的温度下运行的高能量密度锂离子电池（LIB）的瓶颈。已经报道使用固有的电化学稳定的电解质溶剂，例如砜或二腈，是实现高压LIB的一种方法。然而，这些溶剂的主要挑战与它们不良的还原稳定性和在石墨电极上缺乏形成固体电解质中间相（SEI）的能力有关。在此，合成并研究了3-甲基-1,4,2-二恶唑-5-酮（MDO）作为一种新型的高效SEI形成电解质添加剂，该添加剂可以充分抑制碳酸亚丙酯（PC）基中电解质的还原和石墨剥落。电解质。仅添加2 wt％的MDO，LiNi在PC电解质中包含1 M LiPF _6的0.5 Mn _0.3 Co _0.2 O ₂（NMC532）/石墨全电池达到超过450个循环的循环寿命，同时仍保持80％的容量。此外，MDO被证明是氧化稳定的，直到相对于Li / Li ^+的电势高达5.3V 。MDO及其衍生物作为电解质添加剂的进一步发展是迈向基于替代电解质溶剂和高能量密度LIB的高电压稳定电解质配方的一步。