Hard carbon finds critical applications in potassium-ion batteries (PIBs) anodes because of its attractive advantages including low cost and high conductivity. However, the sluggish reaction kinetics and structural instability caused by large K⁺ intercalation/deintercalation limit their storage capability and cycling life. Herein, active sites enriched hard carbon porous nanobelts (NOCNBs) for enhanced K⁺ storage are constructed from mineralized shrimp shells via a self-template assisted pyrolysis strategy. The NOCNBs possess multiscale structure with hierarchical micro/meso/macro-pores, high-level pyrrolic/pyridinic-N and O dual-doping, and large interlayer spacing. Hence, the NOCNBs deliver a high capacity of 468 mAh g⁻¹ at 50 mA g⁻¹ and long cycling life (277 mAh g⁻¹ at 1000 mA g⁻¹ over 1600 cycles), representing one of the best storage capability and cycling stability among the reported carbonaceous electrodes. Density functional theory calculations and kinetic analysis demonstrate that the abundant active sites within NOCNBs can strengthen K adsorption and diffusion, facilitating capacitive-adsorbed storage. The in-situ X-ray diffraction reveals the potassium intercalation mechanism in hard carbon for the first time. Furthermore, they exhibit a superior capacity of 89 mAh g⁻¹ at 100 mA g⁻¹ for potassium dual-ion batteries (PDIBs). This work opens up a new avenue for constructing porous hard carbon to achieve excellent K⁺ storage.

硬碳在钾离子电池（PIB）阳极中具有关键的应用，因为它具有低成本，高导电性等吸引人的优势。然而，由大的K ⁺嵌入/脱嵌引起的缓慢的反应动力学和结构不稳定性限制了它们的储存能力和循环寿命。在本文中，通过自模板辅助热解策略，从矿化的虾壳中构建了用于增强K ⁺储存的富集硬碳多孔纳米带（NOCNB）的活性位点。NOCNB具有多尺度结构，具有分层的微/中/大孔，高水平的吡咯/吡啶-N和O双掺杂，且层间间距大。因此，NOCNB在50 mA g ^-1时可提供468 mAh g ^-1的高容量循环寿命长（在1600个循环中1000 mA g ^-1时为277 mAh g ^-1），是报道的碳质电极中最佳的存储能力和循环稳定性之一。密度泛函理论计算和动力学分析表明，NOCNBs中丰富的活性位点可以增强钾的吸附和扩散，从而促进电容性吸附存储。X射线原位衍射首次揭示了硬碳中的钾插层机理。此外，它们对于钾双离子电池（PDIB）在100 mA g ^-1下表现出89 mAh g ^-1的出色容量。这项工作为构造多孔硬碳以实现出色的K ⁺存储开辟了一条新途径。