Abstract Potassium ion batteries (KIBs) are drawing intensive attention as the next-generation energy storage technology, owning to their similar electrochemical properties to lithium system and rich abundance of potassium resources. The carbonaceous materials with low cost, nontoxicity and high safety have been considered as promising candidates for KIBs anodes. However, they still suffer from several problems, such as poor cycling and rate capability, complex activation process steps and multiple procedures to import heteroatoms doping. Herein, the N-doped carbon nanofibers (NCFs) are fabricated by direct pyrolysis of bio-waste chitin, which is the second most abundant biopolymer throughout nature. The as-prepared NCFs used as KIBs anodes, without any additional activation steps, are systematically investigated for the first time. They deliver high capacity, excellent rate capability and long-term cycling stability, which benefit from the multiple synergistic effects of suitable interlayer spacing, heteroatom doping and unique one dimensional mesoporous structure. With the spotlight of environmental friendliness, low cost and high energy density in energy storage field, the chitin-based NCFs demonstrate great potential for future low-cost energy storage applications.

中文翻译：

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甲壳素衍生的天然掺氮碳纳米纤维中的优异钾储存

摘要 钾离子电池（KIBs）作为下一代储能技术，以其与锂系统相似的电化学特性和丰富的钾资源而备受关注。具有低成本、无毒和高安全性的碳质材料被认为是 KIBs 负极的有希望的候选者。然而，它们仍然存在一些问题，例如循环和倍率能力差、活化过程步骤复杂以及导入杂原子掺杂的多个程序。在此，N 掺杂的碳纳米纤维 (NCF) 是通过生物废物甲壳素的直接热解制造的，甲壳素是自然界中含量第二丰富的生物聚合物。首次系统地研究了所制备的 NCF 作为 KIBs 阳极，无需任何额外的活化步骤。它们具有高容量、优异的倍率性能和长期循环稳定性，这得益于合适的层间距、杂原子掺杂和独特的一维介孔结构的多重协同效应。由于在储能领域具有环保、低成本和高能量密度的特点，几丁质基NCFs在未来低成本储能应用中展现出巨大的潜力。