Potassium‐ion batteries (KIBs) are very promising alternatives to lithium‐ion batteries (LIBs) for large‐scale energy storage. However, traditional carbon anode materials usually show poor performance in KIBs due to the large size of K ions. Herein, a carbonization‐etching strategy is reported for making a class of sulfur (S) and oxygen (O) codoped porous hard carbon microspheres (PCMs) material as a novel anode for KIBs through pyrolysis of the polymer microspheres (PMs) composed of a liquid crystal/epoxy monomer/thiol hardener system. The as‐made PCMs possess a porous architecture with a large Brunauer–Emmett–Teller surface area (983.2 m² g⁻¹), an enlarged interlayer distance (0.393 nm), structural defects induced by the S/O codoping and also amorphous carbon nature. These new features are important for boosting potassium ion storage, allowing the PCMs to deliver a high potassiation capacity of 226.6 mA h g⁻¹ at 50 mA g⁻¹ over 100 cycles and be displaying high stability by showing a potassiation capacity of 108.4 mA h g⁻¹ over 2000 cycles at 1000 mA g⁻¹. The density functional theory calculations demonstrate that S/O codoping not only favors the adsorption of K to the PCMs electrode but also reduces its structural deformation during the potassiation/depotassiation. The present work highlights the important role of hierarchical porosity and S/O codoping in potassium storage.

中文翻译：

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高性能钾离子电池用硫/氧共掺杂的多孔硬碳微球

钾离子电池（KIB）是锂离子电池（LIB）大规模储能的非常有希望的替代品。但是，由于K离子的尺寸较大，传统的碳阳极材料通常在KIB中显示较差的性能。本文报道了一种碳化腐蚀策略，该方法通过热解由碳纳米管组成的聚合物微球（PM）来制备一类硫（S）和氧（O）共掺杂的多孔硬碳微球（PCM）材料作为KIB的新型阳极。液晶/环氧单体/硫醇固化剂体系。制成的PCM具有多孔结构，具有大的Brunauer-Emmett-Teller表面积（983.2 m ² g ^-1），更大的层间距离（0.393 nm），由S / O共掺杂引起的结构缺陷以及无定形碳的性质。这些新功能对于增强钾离子存储非常重要，可以使PCM在100个循环中在50 mA g ^-1下提供226.6 mA hg ^-1的高钾化能力，并通过显示108.4 mA hg的钾化能力而显示出高稳定性^{- 1}超过2000次循环以1000mA克^-1。密度泛函理论计算表明，S / O共掺杂不仅有利于K在PCMs电极上的吸附，而且还减少了钾化/去钾化过程中其结构变形。本工作强调了分层孔隙度和S / O共掺杂在钾存储中的重要作用。