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Deciphering the catalysis essence of vanadium self-intercalated two-dimensional vanadium sulfides (V5S8) on lithium polysulfide towards high-rate and ultra-stable Li-S batteries
Energy Storage Materials ( IF 18.9 ) Pub Date : 2021-09-26 , DOI: 10.1016/j.ensm.2021.09.030
Chao Yue Zhang 1 , Guo Wen Sun 1 , Zu De Shi 1 , Qian Yu Liu 1 , Jiang Long Pan 1 , Yan Chun Wang 1, 2 , Hao Zhao 3 , Geng Zhi Sun 4, 5 , Xiu Ping Gao 1 , Xiao Jun Pan 1 , Jin Yuan Zhou 1
Affiliation  

Atom-intercalated transition metal disulfides (TMDs) have attached much attention mainly due to their highly improved conductivity. But it is few reported that the atom intercalation can enable the TMDs have unexpected catalytic properties, caused by the unit-cell deformation in them. In this work, a type of V0.25-intercalated VS2 (V5S8) nanoflakes was designed via a direct vulcanization method combining Kirkendall heat diffusion effect, and used as the promotor for lithium-sulfur batteries (LSBs). The V5S8 possesses a NiAs crystal structure, in which V atoms occupy the interlayer spacing between VS2 monolayers, which will unavoidably cause the unit-cell deformation. As expected, the CNF@V5S8/S cathodes show a specific capacity of 1260 mAh g−1 at 0.2 C, and can keep 73.65% of the capacity with charge/discharge rate increasing 10 times; while the CNF@VS2/S ones can only retain 54.0% of the initial capacity. Moreover, the CNF@V5S8/S cathodes show an ultralow decay rate of only 0.0312% per cycle for 1500 cycles at 5 C. Furthermore, the catalysis effect of V5S8 on the conversion of lithium polysulfide (Li2Sn, n = 1, 2, 4, 6 and 8) and S8 clusters were systematically discusses. Besides, the V5S8 can further enable LSBs achieve a high areal capacity (8.2 mAh cm−2 with sulfur loading of 7.8 mg cm−2) and a high dynamic flexible stability at bending angle between 0 and 180 °.



中文翻译:

解读钒自插层二维硫化钒(V5S8)在多硫化锂上对高倍率超稳定锂硫电池的催化本质

原子插层过渡金属二硫化物(TMD)因其高度提高的导电性而备受关注。但很少有报道称原子嵌入可以使 TMD 具有意想不到的催化性能,这是由它们的晶胞变形引起的。在这项工作中,通过结合柯肯德尔热扩散效应的直接硫化方法设计了一种 V 0.25插层 VS 2 (V 5 S 8 ) 纳米薄片,并将其用作锂硫电池 (LSB) 的促进剂。V 5 S 8具有 NiAs 晶体结构,其中 V 原子占据 VS 2之间的层间距单层,这将不可避免地导致晶胞变形。正如预期的那样,CNF@V 5 S 8 /S 正极在 0.2 C 下的比容量为 1260 mAh g -1,并且在充放电倍率提高 10 倍的情况下可以保持 73.65% 的容量;而CNF@VS 2 /S只能保留初始容量的54.0%。此外,CNF@V 5 S 8 /S 正极在 5 C 下 1500 次循环显示出每循环仅 0.0312% 的超低衰减率。此外,V 5 S 8对多硫化锂(Li 2 S n , n = 1, 2, 4, 6 和 8) 和 S 8集群进行了系统的讨论。此外,V 5 S 8可以进一步使LSBs实现高面积容量(8.2 mAh cm -2,硫负载量为7.8 mg cm -2)和0°和180°之间的弯曲角下的高动态柔性稳定性。

更新日期:2021-10-02
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