Antimony (Sb) is an attractive anode material for sodium-ion batteries (SIBs) owing to its low operating potential, low cost, and high theoretical capacity. However, the large volume expansion of Sb during the Na alloying/dealloying process, which greatly limits its application in SIBs. Simultaneously, as the temperature decreases, the formation of a poor coating on the anode surface significantly increase the difficulty of Na+ transmission. Herein, Sb-graphite-NaF (SCF) ternary composites were prepared by an easy to operate and low-cost ball milling method, which significantly improved the cycling stability and extended to the operation temperature of Sb-base SIBs. A small amount of NaF induces the formation of an inorganic-dominated NaF-rich stable solid electrolyte interphase (SEI) on the Sb anode surface, which can cooperate with graphite to inhibit volume expansion of the Sb particles during sodium storage, enhance conductivity and accelerate Na+ diffusion at room and low temperatures. As a result, the SCF electrode with propylene carbonate-base electrolyte delivered a discharge capacity of 458.4 mAh g−1 after 160 cycles at 500 mA g−1 at 20 °C. When matched with diethylcarbonate-based electrolyte at −20 °C, it had a specific capacity of 299.8 mAh g−1 after 120 cycles and a capacity retention rate of 86.2 %. This study shows that the interface stabilization strategy with a suitable electrolyte can improve the cycling stability of anode materials, provide a new idea for constructing NaF-rich SEI, and a new approach for applying Sb-based materials in low-temperature SIBs.

中文翻译：

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球磨法制备的界面稳定策略实现 Sb 负极低温储钠


锑 （Sb） 是一种有吸引力的钠离子电池 （SIB） 负极材料，因为它具有低工作潜力、低成本和高理论容量。然而，在 Na 合金化/脱合金过程中 Sb 的大量体积膨胀极大地限制了其在 SIB 中的应用。同时，随着温度的降低，在阳极表面形成不良涂层会显著增加 Na+ 传输的难度。本文采用易于操作、低成本的球磨法制备了 Sb-石墨-NaF （SCF） 三元复合材料，显著提高了循环稳定性，并扩展到 Sb-base SIBs 的工作温度。少量的 NaF 诱导在 Sb 负极表面形成以无机物为主的富含 NaF 的稳定固体电解质界面 （SEI），该界面可以与石墨配合抑制钠储存过程中 Sb 颗粒的体积膨胀，增强电导率并加速 Na+ 在室温和低温下的扩散。结果，在 20 °C 下以 500 mA g-1 循环 160 次后，带有碳酸丙烯酯基电解质的 SCF 电极提供了 458.4 mAh g-1 的放电容量。 当在 -20 °C 下与碳酸二乙酯基电解质匹配时，它在 120 次循环后具有 299.8 mAh g-1 的比容量，容量保持率为 86.2 %。研究表明，使用合适电解质的界面稳定策略可以提高负极材料的循环稳定性，为构建富含 NaF 的 SEI 提供了新思路，并为 Sb 基材料在低温 SIB 中的应用提供了新途径。