Bimetallic sulfides are prospective candidates as Na-ion battery (NIB) anodes owing to their abundant redox active sites and high specific capacities, while the rate and cycling performances are limited due to their severe mechanical strain and sluggish reaction kinetics. Herein, for the first time, a series of cubic spinel XIn₂S₄ (X = Fe, Co, Mn) anodes is proposed for superfast and ultrastable Na-ion storage. The FeIn₂S₄ delivers the best electrochemical performance among them with the amazing results especially for its superfast charging (9–13 s per charge with ≈300 mAh g⁻¹ input) and ultrastable cycling capabilities (25 K cycles with ultralow 0.000801% capacity loss per cycle). Further density functional theory calculations and experimental results indicate that Fe substitution at tetrahedral sites of cubic spinel In_2.77S₄ can significantly enhance its electrical conductivity, Na-ion binding kinetics, and pseudocapacitive contributions, reduce its Na-ion diffusion barrier, and relieve its mechanical strain. Moreover, the inherent In skeleton at octahedral sites can induce a complementary reaction to stabilize the conversion-type Fe-based components. Furthermore, the FeIn₂S₄-based full cells with excellent electrochemical performance are assembled. This work demonstrates the feasibility of enhancing the synergies within bimetallic sulfides to realize remarkable electrochemical performance.

中文翻译：

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立方尖晶石 XIn2S4 (X = Fe, Co, Mn)：一种用于超快和超稳定钠离子存储的新型负极材料

双金属硫化物由于其丰富的氧化还原活性位点和高比容量而成为钠离子电池（NIB）负极的潜在候选材料，而由于其严重的机械应变和缓慢的反应动力学，其倍率和循环性能受到限制。在此，首次提出了一系列立方尖晶石 XIn ₂ S ₄ (X = Fe, Co, Mn) 阳极用于超快和超稳定的钠离子存储。FeIn ₂ S ₄提供了其中最好的电化学性能，尤其是其超快充电（每次充电 9-13 秒，≈300 mAh g ^-1输入）和超稳定循环能力（25 K 循环，每循环具有 0.000801% 的超低容量损失）。进一步的密度泛函理论计算和实验结果表明，在立方尖晶石 In _2.77 S ₄四面体位点的 Fe 取代可以显着提高其电导率、Na 离子结合动力学和赝电容贡献，降低其 Na 离子扩散势垒，并减轻其机械应变。此外，八面体位点的固有 In 骨架可以引发互补反应以稳定转化型 Fe 基组分。此外，FeIn ₂ S ₄组装了具有优异电化学性能的全电池。这项工作证明了增强双金属硫化物内的协同作用以实现显着电化学性能的可行性。