Abstract K-ion batteries (KIBs) are widely considered as a promising alternative to Li-ion batteries (LIBs) due to the cost effective and earth abundant features of K. However, identifying a potential anode for KIBs showing good capacity and stability is still challenging. Because traditional graphite suffers from poor stability owing to the large volume expansion during the insertion/extraction of K ions. Non-graphite carbon is a good candidate because of the disordered nature. A facile high temperature pyrolysis method was adopted to obtain bio-derived carbon materials. Among different kinds of biomass precursors, the porous dandelion seed with nitrogen doping shows the best electrochemical performance with a specific capacity of 168 mAh g−1. The nitrogen-doped carbon presents good K ion adsorption capability and enhanced wettability, which is demonstrated in Fig.S1. Moreover, after introducing activation agent (KOH) in the carbonization process, the capacity in improved to 243 mAh g−1. Meanwhile, the as-prepared carbon material delivers good capacity retention of 91% after 100 cycles. Therefore, the hierarchically porous doped carbon derived from renewable biomass precursor shows great economical potential as KIBs anode.

中文翻译：

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生物衍生的分级多孔杂原子掺杂碳作为高性能钾离子电池的负极

摘要 钾离子电池（KIBs）由于钾的成本效益和丰富的地球特性而被广泛认为是锂离子电池（LIBs）的有前途的替代品。然而，确定具有良好容量和稳定性的潜在负极仍然是具有挑战性的。因为传统的石墨由于在 K 离子的插入/脱出过程中体积膨胀大而稳定性差。由于无序性质，非石墨碳是一个很好的候选者。采用简便的高温热解方法获得生物衍生碳材料。在不同种类的生物质前体中，掺杂氮的多孔蒲公英种子表现出最好的电化学性能，比容量为 168 mAh g-1。掺氮碳具有良好的 K 离子吸附能力和增强的润湿性，如图S1所示。此外，在碳化过程中引入活化剂（KOH）后，容量提高到243 mAh g-1。同时，所制备的碳材料在 100 次循环后具有 91% 的良好容量保持率。因此，源自可再生生物质前体的分级多孔掺杂碳作为 KIBs 阳极显示出巨大的经济潜力。