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Vanadium atom modulated electrocatalyst for accelerated Li-S chemistry
Yu, Songlin1; Sun, Yingjie2; Song, Lixian1; Cao, Xuan1; Chen, Le1; An, Xingtao2; Liu, Xiaohong3; Cai, Wenlong4; Yao, Tao5; Song, Yingze1
2021-11-01
摘要Extensive efforts have been made to attain practically viable Li-S batteries. Nevertheless, issues mainly pertaining to the notorious polysulfide shuttle and the sluggish sulfur redox kinetics remain in enhancing the energy density and cycling lifespan of batteries. Herein, we propose an atom-level modulation engineering strategy to design a new model electrocatalyst of V-N-C delicately integrating twinborn isolated vanadium atoms and ultra small-sized vanadium nitride (VN) nanoparticles in a carbonaceous framework for Li-S chemistry. Combining results from synchrotron X-ray three-dimensional nano-computed tomography (X-ray 3D Nano-CT), operando Raman and first-principles calculations, we conclude that, such a V-N-C electrocatalyst system synergizes the merits of highly efficient single atom V-N-C coordination (SAV-N-C) as well as site-rich VN centers, and thus effectively promotes both the formation and decomposition of Li2S during discharge and charge procedures, respectively. As a result, the highly active V-N-C electrocatalyst can enable superior rate capability and long-term cycling stability with a low decay of 0.052% per cycle up to 1000 cycles at 2 C. Furthermore, the designed S/V-N-C cathode still affords favorable electrochemical performances even under the scenarios of elevated sulfur loading (8.1 mg cm(-2)) and flexible pouch cell configurations, holding great promise in future practical implementation.
关键词Li-S chemistry V-N-C electrocatalyst system Vanadium atom modulation engineering Polysulfide regulation Sulfur redox reaction kinetics
DOI10.1016/j.nanoen.2021.106414
发表期刊NANO ENERGY
ISSN2211-2855
卷号89页码:13
通讯作者Song, Yingze(yzsong@swust.edu.cn) ; Zhang, Wei(zhangwei@cigit.ac.cn)
收录类别SCI
WOS记录号WOS:000709614100005
语种英语