Bamboo‐Like Hollow Tubes with MoS2/N‐Doped‐C Interfaces Boost Potassium‐Ion Storage |
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Authors: | Baorui Jia Qiyao Yu Yongzhi Zhao Mingli Qin Wei Wang Zhiwei Liu Cheng‐Yen Lao Ye Liu Haowang Wu Zili Zhang Xuanhui Qu |
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Affiliation: | 1. Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, China;2. Beijing Key Laboratory for Advanced Powder Metallurgy and Particulate Materials, University of Science and Technology Beijing, Beijing, China;3. Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing, China;4. Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UK;5. School of Material Science and Engineering, Xiangtan University, Hunan, China |
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Abstract: | Potassium‐ion batteries (KIBs) are new‐concept of low‐cost secondary batteries, but the sluggish kinetics and huge volume expansion during cycling, both rooted in the size of large K ions, lead to poor electrochemical behavior. Here, a bamboo‐like MoS2/N‐doped‐C hollow tubes are presented with an expanded interlayer distance of 10 Å as a high‐capacity and stable anode material for KIBs. The bamboo‐like structure provides gaps along axial direction in addition to inner cylinder hollow space to mitigate the strains in both radial and vertical directions that ultimately leads to a high structural integrity for stable long‐term cycling. Apart from being a constituent of the interstratified structure the N‐doped‐C layers weave a cage to hold the potassiation products (polysulfide and the Mo nanoparticles) together, thereby effectively hindering the continuing growth of solid electrolyte interphase in the interior of particles. The density functional theory calculations prove that the MoS2/N‐doped‐C atomic interface can provide an additional attraction toward potassium ion. As a result, it delivers a high capacity at a low current density (330 mAh g?1 at 50 mA g?1 after 50 cycles) and a high‐capacity retention at a high current density (151 mAh g?1 at 500 mA g?1 after 1000 cycles). |
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Keywords: | anodes interfaces MoS2 N‐doped‐C potassium‐ion batteries |
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