Although carbon materials have great potential for potassium ion battery (KIB) anodes due to their structural stability and abundant carbon-containing resources, the limited K⁺-intercalated capacity impedes their extensive applications in energy storage devices. Current research studies focus on improving the surface-induced capacitive behavior to boost the potassium storage capacity of carbon materials. Herein, we designed edge-nitrogen (pyridinic-N and pyrrolic-N) doped carbon spheres with a hierarchically porous structure to achieve high potassium storage properties. The electrochemical tests confirmed that the edge-nitrogen induced active sites were conducive for the adsorption of K⁺, and the hierarchical porous structure promoted the generation of stable solid electrolyte interphase (SEI) films, both of which endow the resulting materials with a high reversible capacity of 381.7 mA h g^-1 at 0.1 A g^-1 over 200 cycles and an excellent rate capability of 178.2 mA h g^-1 at 5 A g^-1. Even at 5 A g^-1, the long-term cycling stability of 5000 cycles was achieved with a reversible capacity of 190.1 mA h g^-1. This work contributes to deeply understand the role of the synergistic effect of edge-nitrogen induced active sites and the hierarchical porous structure in the potassium storage performances of carbon materials.

中文翻译：

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提高用于超稳定钾离子电池负极的边缘氮掺杂分级多孔碳球的 K+ 吸附能力

尽管碳材料由于其结构稳定性和丰富的含碳资源而具有作为钾离子电池（KIB）负极的巨大潜力，但有限的 K ⁺插层容量阻碍了其在储能设备中的广泛应用。目前的研究重点是改善表面诱导电容行为，以提高碳材料的钾存储能力。在此，我们设计了具有分级多孔结构的边缘氮（吡啶-N和吡咯-N）掺杂的碳球，以实现高钾存储性能。电化学测试证实，边缘氮诱导的活性位点有利于 K ⁺的吸附。, 分级多孔结构促进了稳定的固体电解质界面 (SEI) 膜的生成，这两者都赋予所得材料在 0.1 A g ^{-1 下}在 200 次循环下具有 381.7 mA hg ^-1的高可逆容量和优异的倍率178.2 mA hg ^-1在 5 A g ^{-1 的能力}。即使在 5 A g ^{-1 下}，也实现了 5000 次循环的长期循环稳定性，可逆容量为 190.1 mA hg ^-1。这项工作有助于深入理解边缘氮诱导活性位点和分级多孔结构的协同作用在碳材料储钾性能中的作用。