The development of high-voltage dual-ion batteries (DIBs) is greatly hindered by the structure degradation of graphite cathodes during the (de-)intercalation of bulky anions, the electrolyte oxidative decomposition at high voltages, and inadequate cathode-electrolyte interphase (CEI) protection. Here, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) is introduced as an electrolyte additive, which preferentially enters into the first shell structure of PF6− solvation, contributing to high oxidation stability of the electrolyte and formation of an inorganic LiF-rich CEI layer. This layer stabilizes the graphite structure and enhances the anion (de-)intercalation reversibility and transport kinetics. Consequently, the Li||graphite half cell with TTE in the electrolyte exhibits an ultrahigh rate capability (95.6 % at 30 C) and a remarkable capacity retention (67.6 % after 5000 cycles). The impressive performance is further demonstrated in the graphite||graphite full cell, showcasing exceptional cycle stability (91.9 % after 1000 cycles). This study underscores the significance of anionic solvent chemistry and CEI components on cathode materials for DIBs.

中文翻译：

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调节阴离子溶剂化和阴极电解质界面以提高高压双离子电池的可逆性和动力学


高压双离子电池（DIB）的发展受到大体积阴离子脱嵌过程中石墨阴极结构退化、高电压下电解质氧化分解以及阴极-电解质界面不足（CEI）的严重阻碍。 ） 保护。这里引入1,1,2,2-四氟乙基-2,2,3,3-四氟丙醚（TTE）作为电解质添加剂，它优先进入PF6−溶剂化的第一壳结构，有助于高氧化稳定性电解质并形成富含 LiF 的无机 CEI 层。该层稳定了石墨结构并增强了阴离子（脱）嵌入的可逆性和传输动力学。因此，电解质中具有TTE的锂石墨半电池表现出超高的倍率性能（30℃下为95.6%）和显着的容量保持率（5000次循环后为67.6%）。石墨全电池进一步证明了令人印象深刻的性能，表现出卓越的循环稳定性（1000 次循环后为 91.9%）。这项研究强调了阴离子溶剂化学和 CEI 成分对 DIB 阴极材料的重要性。