Two-dimensional layered transition metal disulphides for effective encapsulation of high-capacity lithium sulphide cathodes
Two-dimensional layered transition metal disulphides for effective encapsulation of high-capacity lithium sulphide cathodes
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DOI：
10.1038/ncomms6017
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发表时间：
2014-09-01
影响因子：
16.6
通讯作者：
Cui, Yi
中科院分区：
文献类型：
--
作者：
Seh, Zhi Wei;Yu, Jung Ho;Cui, Yi
全锂硫化锂(Li2S)是一种很有前途的新型储能正极材料。与硫磺阴极一样，Li2S阴极需要有效的封装，以减少中间多硫化锂(Li2Sn4-8)物种在电解液中的溶解。在这里，我们报道了用二维层状过渡金属二硫化物包裹Li2S阴极，这种二硫化物具有高导电性和与Li2S/Li2Sn物种的强结合。特别是，使用二硫化钛作为包覆材料，我们展示了在高C速率条件下(4C)的高比容量为503mAhg(Li2S)(-1)，以及在高质量负载条件下(5.3 mg(Li2S)cm(-2))的高比容量为3.0mAhcm(-2)。这项工作为用过渡金属二硫化物代替传统的碳基材料有效地包裹高容量电极材料开辟了新的前景。
Fully lithiated lithium sulphide (Li2S) is currently being explored as a promising cathode material for emerging energy storage applications. Like their sulphur counterparts, Li2S cathodes require effective encapsulation to reduce the dissolution of intermediate lithium polysulphide (Li2Sn, n = 4-8) species into the electrolyte. Here we report, the encapsulation of Li2S cathodes using two-dimensional layered transition metal disulphides that possess a combination of high conductivity and strong binding with Li2S/Li2Sn species. In particular, using titanium disulphide as an encapsulation material, we demonstrate a high specific capacity of 503 mAh g(Li2S)(-1) under high C-rate conditions (4C) as well as high areal capacity of 3.0 mAhcm(-2) under high mass-loading conditions (5.3 mg(Li2S) cm(-2)). This work opens up the new prospect of using transition metal disulphides instead of conventional carbon-based materials for effective encapsulation of high-capacity electrode materials.