The commercialization of sodium-ion batteries (SIBs) is tremendously limited as performance decline in extreme environments (such as below 0 ℃). This work proposes remarkable low-temperature (low-T) SIBs based on 0.5 M NaPF₆ diglyme electrolyte. By a series of in-depth analysis, including XPS, temperature-dependent EIS, in- and ex-situ XRD, etc., finding that the weakly solvated structure of Na⁺-diglyme is beneficial to accelerating diffusivity of Na⁺ and reducing charge transfer energy (from 461.9 to 158.6 meV), which is effectively to ameliorate the low-T sodium storage mechanism. Moreover, The NaF-rich cathode electrolyte interphase (CEI) formed in diglyme is conducive to stabilize the interfacial structure and accelerate transport of Na⁺. All these merits collectively lead to high adaptability of low-concentration diglyme-based electrolyte to low-T. It has been verified that this system delivers 95.6% of room-temperature (RT) capacity, and full-cell delivers huge superiority in lifespan (working stably for 10,000 cycles) at − 20 ℃. Even at − 60 ℃, the battery still attains high capacity density (79.2 mAh g⁻¹). These results provide new research ideas for improving the low-T performance of energy storage equipment.

钠离子电池（SIBs）的商业化受到极大限制，因为在极端环境（例如0℃以下）下性能下降。这项工作提出了基于 0.5 M NaPF ₆二甘醇二甲醚电解质的卓越低温 (low-T) SIB。通过XPS、温度依赖性EIS、原位和非原位XRD等一系列深入分析，发现Na + -二甘醇二甲醚的弱溶剂化结构有利于加速Na + 的扩散^和降低电荷转移能量（从 461.9 到 158.6 meV），这有效地改善了低 T 钠存储机制。此外，二甘醇二甲醚中形成的富 NaF 正极电解质界面 (CEI) 有利于稳定界面结构并加速 Na ^{+的传输。}. 所有这些优点共同导致低浓度二甘醇二甲醚基电解质对低 T 的高度适应性。经验证，该系统可提供 95.6% 的室温 (RT) 容量，全电池在 − 20 ℃ 下具有巨大的寿命优势（可稳定工作 10,000 次）。即使在-60 ℃，电池仍能达到高容量密度（79.2 mAh g ^-1）。这些结果为提高储能设备的低温性能提供了新的研究思路。