Abstract Sb2Se3 based anodes are widely studied for advanced Na-ion batteries. However, their Na storage performance at high rates is limited to 2000 mA g−1 because of poor kinetics of redox reactions. Here, the heterointerfacial interactions taking place between Sb2Se3 and functionalized CNTs are probed to understand the formation of Sb–O–C and Se–C bonds in the amorphous a-Sb2Se3/CNT composite using the density functional theory and ab-initio molecular dynamics simulations. The distinct morphologies and thicknesses of solid electrolyte interface layers formed on crystalline c-Sb2Se3 and a-Sb2Se3/CNT composite electrodes are revealed by advanced cryogenic transmission electron microscopy and their influences on the kinetics of redox reactions in the corresponding electrodes are identified. The structurally robust a-Sb2Se3/CNT composite electrode exhibits four orders of magnitude higher Na-ion diffusion coefficient than the crystalline c-Sb2Se3 counterpart, giving rise to an exceptional high-rate capacity of 454 mA h g−1 at 12800 mA g−1 and capacity retention of over 62% after 200 cycles at 10000 mA g−1. The full cells containing the composite electrodes present energy and power densities of ∼175 Wh kg−1 at 0.5C and ∼5784 W kg−1 at 80C, respectively, and stable cyclic performance up to 120 cycles.

中文翻译：

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揭示用于超快储钠的无定形 Sb2Se3/CNT 复合阳极的固体电解质界面形态和电化学动力学

摘要 Sb2Se3 基负极被广泛研究用于先进的钠离子电池。然而，由于氧化还原反应动力学较差，它们在高速率下的 Na 存储性能仅限于 2000 mA g-1。在这里，使用密度泛函理论和 ab-initio 分子动力学模拟，探究了 Sb2Se3 和功能化 CNT 之间发生的异质界面相互作用，以了解无定形 a-Sb2Se3/CNT 复合材料中 Sb-O-C 和 Se-C 键的形成. 通过先进的低温透射电子显微镜揭示了在结晶 c-Sb2Se3 和 a-Sb2Se3/CNT 复合电极上形成的固体电解质界面层的不同形态和厚度，并确定了它们对相应电极中氧化还原反应动力学的影响。结构坚固的 a-Sb2Se3/CNT 复合电极表现出比结晶 c-Sb2Se3 对应物高四个数量级的钠离子扩散系数，从而在 12800 mA g-1 下产生 454 mA hg-1 的卓越高倍率容量在 10000 mA g-1 下循环 200 次后容量保持率超过 62%。包含复合电极的全电池在 0.5C 和 80C 时的能量密度和功率密度分别为~175 Wh kg-1 和~5784 W kg-1，并且循环性能稳定达 120 次。