1] Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA [2].
1] Department of Chemical Engineering, Stanford University, Stanford, California 94305, USA [2].
Nat Commun. 2014 May 27;5:3943. doi: 10.1038/ncomms4943.
Lithium-sulphur batteries are attractive owing to their high theoretical energy density and reasonable kinetics. Despite the success of trapping soluble polysulphides in a matrix with high surface area, spatial control of solid-state sulphur and lithium sulphide species deposition as a critical aspect has not been demonstrated. Herein, we show a clear visual evidence that these solid species deposit preferentially onto tin-doped indium oxide instead of carbon during electrochemical charge/discharge of soluble polysuphides. To incorporate this concept of spatial control into more practical battery electrodes, we further prepare carbon nanofibers with tin-doped indium oxide nanoparticles decorating the surface as hybrid three-dimensional electrodes to maximize the number of deposition sites. With 12.5 μl of 5 M Li2S8 as the catholyte and a rate of C/5, we can reach the theoretical limit of Li2S8 capacity ~\n1,470 mAh g(-1) (sulphur weight) under the loading of hybrid electrode only at 4.3 mg cm(-2).
锂硫电池因其高理论能量密度和合理的动力学而备受关注。尽管在高表面积的基质中捕获可溶性多硫化物的方法已经取得成功，但作为一个关键方面，固态硫和硫化锂物种的空间控制沉积尚未得到证明。在此，我们清楚地表明，在可溶性多硫化物的电化学充放电过程中，这些固体物质优先沉积在掺锡氧化铟而不是碳上。为了将这种空间控制的概念应用于更实际的电池电极，我们进一步制备了表面修饰有掺锡氧化铟纳米颗粒的碳纳米纤维作为混合三维电极，以最大限度地增加沉积点的数量。在以 12.5 μl 的 5 M Li2S8 作为电解液，以 C/5 的倍率进行测试时，在混合电极的负载下，我们仅能达到理论极限的 Li2S8 容量~1,470 mAh g(-1)（硫的重量），此时的负载量仅为 4.3 mg cm(-2)。
