Battery Separators Functionalized with Edge-Rich MoS(2)/C Hollow Microspheres for the Uniform Deposition of Li(2)S in High-Performance Lithium–Sulfur Batteries

As promising energy storage systems, lithium–sulfur (Li–S) batteries have attracted significant attention because of their ultra-high energy densities. However, Li–S battery suffers problems related to the complex phase conversion that occurs during the charge–discharge process, particularly the deposition of solid Li(2)S from the liquid-phase polysulfides, which greatly limits its practical application. In this paper, edge-rich MoS(2)/C hollow microspheres (Edg-MoS(2)/C HMs) were designed and used to functionalize separator for Li–S battery, resulting in the uniform deposition of Li(2)S. The microspheres were fabricated through the facile hydrothermal treatment of MoO(3)–aniline nanowires and a subsequent carbonization process. The obtained Edg-MoS(2)/C HMs have a strong chemical absorption capability and high density of Li(2)S binding sites, and exhibit excellent electrocatalytic performance and can effectively hinder the polysulfide shuttle effect and guide the uniform nucleation and growth of Li(2)S. Furthermore, we demonstrate that the Edg-MoS(2)/C HMs can effectively regulate the deposition of Li(2)S and significantly improve the reversibility of the phase conversion of the active sulfur species, especially at high sulfur loadings and high C-rates. As a result, a cell containing a separator functionalized with Edg-MoS(2)/C HMs exhibited an initial discharge capacity of 935 mAh g(−1) at 1.0 C and maintained a capacity of 494 mAh g(−1) after 1000 cycles with a sulfur loading of 1.7 mg cm(−2). Impressively, at a high sulfur loading of 6.1 mg cm(−2) and high rate of 0.5 C, the cell still delivered a high reversible discharge capacity of 478 mAh g(−1) after 300 cycles. This work provides fresh insights into energy storage systems related to complex phase conversions. [Image: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40820-019-0275-z) contains supplementary material, which is available to authorized users.