An adequate wide temperature electrolyte for high nickel ternary cathode is urgent to further develop high energy density batteries. Herein, a comprehensive double-salt local high-concentration sulfolane-based electrolyte (DLi) is proposed with specific sheath structure to build stable interface on the LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) cathode at wide operating temperature between −60 and 55 °C. Lithium perchlorate (LiClO₄) in combination with high concentration lithium bis-(trifluoromethanesulfonyl) imide (LiTFSI) strengthens the internal interaction between anion and cation in the solvation structure, increasing Li⁺ transference number of the electrolyte to 0.61. Moreover, the structure and component characteristics of the passive interface layer on NCM811 are modulated, decreasing desolvation energy of Li⁺ ions, benefiting Li⁺ transport dynamics especially at low temperature, and also ensuring the interfacial stability at a wide operating temperature range. As a result, the cathode with DLi exhibits excellent high-temperature storage performance and high capacity retention of 80.5% in 100 cycles at 55 °C. Meanwhile, the Li∥NCM811 cells can deliver high discharge capacity of 160.1, 136.1, and 110.3 mAh·g⁻¹ under current density of 0.1 C at −20, −40, and −60 °C, maintaining 84.5%, 71.8%, and 58.2% of the discharge capacity at 30 °C, respectively. Moreover, it enables NCM811 cathode to achieve a reversible capacity of 142.8 mAh·g⁻¹ in 200 cycles at −20 °C and 0.2 C. Our studies shed light on the molecular strategy of wide operational temperature electrolyte for high nickel ternary cathode.

一种适用于高镍三元正极的宽温电解质是进一步开发高能量密度电池的迫切需要。在此，本文提出了一种具有特定鞘层结构的综合双盐局部高浓度环丁_砜基电解质（DLi），以_在-60至-60至55°C。高氯酸锂 (LiClO ₄ ) 与高浓度双(三氟甲磺酰) 亚胺锂 (LiTFSI) 的结合增强了溶剂化结构中阴离子和阳离子之间的内部相互作用，增加了 Li ⁺电解质的转移数为 0.61。此外，NCM811 上的无源界面层的结构和组分特性被调制，降低了 Li ⁺离子的去溶剂化能，有利于 Li ⁺传输动力学，特别是在低温下，同时也保证了在宽工作温度范围内的界面稳定性。因此，具有 DLi 的正极表现出优异的高温存储性能和 80.5% 的高容量保持率，在 55°C 下 100 次循环。同时，Li∥NCM811 电池可提供 160.1、136.1 和 110.3 mAh·g ^{-1的高放电容量}在-20、-40和-60°C的0.1 C电流密度下，分别在30°C时保持84.5%、71.8%和58.2%的放电容量。此外，它使NCM811正极在-20℃和0.2℃下200次循环后 的可逆容量达到142.8 mAh·g ^{-1 。我们的研究揭示了宽工作温度电解质用于高镍三元正极的分子策略。}