Metal selenides as promising anode materials for potassium ion batteries (PIBs) have attracted great research attention. However, it is still a challenge to promote its practical application due to the unsatisfactory cyclability resulting from large volume variation and sluggish kinetics. Herein, we tackle this issue by focusing on a promising but undemonstrated anode, bismuth selenide for PIBs which possesses a high theoretical capacity and good electronic conductivity. Benefitting from the carbon layer coating, Bi₂Se₃@C has the capability to inhibit self-aggregation and buffer the volume expansion, leading to outstanding potassium-ion storage capability. It exhibits a very high reversible capacity of 526 mA h g⁻¹ at 50 mA g⁻¹, as well as superior cyclability and rate capability while maintaining a high capacity of 214 mA h g⁻¹ at 1.0 A g⁻¹ after 1000 cycles. Furthermore, its fast and reversible ion storage mechanism was verified, which first involves conversion and subsequent alloying redox reactions. This work enriches the understanding and development of stable conversion/alloying-based anodes for high-performance potassium-ion batteries.

中文翻译：

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限制在薄碳层中的硒化铋纳米片作为先进钾离子电池的负极材料

金属硒化物作为钾离子电池（PIBs）的有前途的负极材料引起了极大的研究关注。然而，由于体积变化大和动力学缓慢导致循环性不理想，促进其实际应用仍然是一个挑战。在此，我们通过专注于具有高理论容量和良好电子导电性的用于 PIB 的有前途但尚未证明的阳极硒化铋来解决这个问题。得益于碳层涂层，Bi ₂ Se ₃ @C 具有抑制自聚集和缓冲体积膨胀的能力，从而具有出色的钾离子存储能力。它表现出526毫安Hg的非常高的可逆容量^-1在50mA克^-1，以及优异的循环性能和倍率性能，同时在 1.0 A g ^-1 1000 次循环后仍保持 214 mA hg ^-1的高容量。此外，验证了其快速可逆的离子存储机制，这首先​​涉及转化和随后的合金化氧化还原反应。这项工作丰富了对高性能钾离子电池稳定转化/合金阳极的理解和开发。