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Hollow Carbon Nanospheres for Capacitive-Dominated Potassium-Ion Storage
Chemical Engineering Journal ( IF 13.3 ) Pub Date : 2020-10-16 , DOI: 10.1016/j.cej.2020.127383
Yongqiang He , Junpeng Xue , Min Yang , Tao Huang , Xiaohong Xia , Yuxi Chen , Hongbo Liu

Carbonaceous material is considered as the most promising anode material for potassium ion batteries (KIBs) in the advantages of low price, stable physical/chemical properties, and renewable resources. However, the moderate capacity and sluggish kinetics cast a shadow over its application. Here, we synthesize multiple active sites decorated porous hollow carbon nanospheres (S/N-PHCs) by a one-step large scalable carbonization method with polypyrrole coated polystyrene and low-cost sulfur as precursors. The obtained S/N-PHCs exhibits an amorphous nanocarbon structure with high specific surface area (502.2 m2 g-1) and S, N content of 9.12 and 3.14 at.%, respectively. The porous hollow nanospheres structure promotes the fully utilization of multiple active sites and a capacitive-dominated K+ storage. Consequently, the S/N-PHCs electrode delivers an ultrahigh specific capacity of 460.6 mAh g-1 at a current density of 100 mA g-1 with an initial Coulombic efficiency of 67.7% and excellent rate capability of 228.1 mAh g−1 at 5000 mA g−1. Moreover, a high reversible capacity of 249.7 mAh g-1 can be retained over 1000 cycles at 1000 mA g−1 (83.4% of the initial specific capacity), demonstrating a remarkable cycle stability. This work provides a scalable and environmentally friendly strategy to achieve hierarchical amorphous carbon as superior anode for KIBs.



中文翻译:

中空碳纳米球用于电容控制的钾离子存储

碳质材料以其低廉的价格,稳定的物理/化学特性和可再生资源的优势被认为是钾离子电池(KIB)最有希望的负极材料。但是,适中的容量和缓慢的动力学为其应用蒙上了一层阴影。在这里,我们以聚吡咯涂层聚苯乙烯和低成本硫为前体,通过一步一步可大规模碳化的方法,合成了多个活性部位修饰的多孔空心碳纳米球(S / N-PHCs)。所获得的S / N-PHCs具有高比表面积(502.2 m 2 g -1)的非晶态纳米碳结构。)和S,N含量分别为9.12和3.14 at。%。多孔的空心纳米球结构促进了多个活性位点的充分利用和以电容为主的K +存储。因此,S / N-PHCs电极在100 mA g -1的电流密度下可提供460.6 mAh g -1的超高比容量,初始库仑效率为67.7%,在5000时的出色倍率能力为228.1 mAh g -1 mA g -1。此外,在1000 mA g -1的1000个循环中可以保持249.7 mAh g -1的高可逆容量(初始比容量的83.4%),具有出色的循环稳定性。这项工作提供了一种可扩展且对环境友好的策略,以实现分层无定形碳作为KIB的优良阳极。

更新日期:2020-10-17
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