SiO2@MoS2 core–shell nanocomposite layers with high lithium ion diffusion as a triple polysulfide shield for high performance lithium–sulfur batteries. Issue 13 (13th March 2019)

• Record Type: Journal Article
• Authors: Wu, Jingyi; You, Na; Li, Xiongwei; Zeng, Hongxia; Li, Shuai; Xue, Zhigang; Ye, Yunsheng; Xie, Xiaolin
• Is Part Of: Journal of materials chemistry. Volume 7:Issue 13(2019)
• Page Start: 7644
• Page End: 7653
• Publication Date: 2019-03-13
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9ta00982e
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : The synergistic effect of the SiO2 @MoS2 core–shell nanocomposite simultaneously facilitates Li + diffusion and provides triple confinement of polysulfides. Abstract : This study introduces an improved design of interlayers to achieve a balance between high Li + diffusion and polysulfide inhibition in lithium–sulfur batteries. The design involves encapsulating mesoporous SiO2 nanospheres in few-layer MoS2 nanosheets via a facile one-step self-assembly to form a core–shell nanocomposite (SiO2 @MoS2 ). The SiO2 @MoS2 layer overlaid on a sulfur cathode simultaneously intercepts polysulfides and ensures rapid Li + diffusion. Few-layer MoS2 as the shell is capable of breaking up polysulfides by a catalytic reaction, while mesoporous SiO2 as the core allows for physiochemical adsorption of such species; moreover, the densely packed hermetic SiO2 @MoS2 nanocomposite layer provides an additional physical shield against polysulfide diffusion, realizing the full protection of the whole cathode. At the same time, the high Li + density in the nanolayered MoS2 shell and the additional Li + pathways created by the mesoporous SiO2 core allow for fast Li + diffusion. Thus, a pristine sulfur cathode battery with a SiO2 @MoS2 interlayer exhibits an outstanding electrochemical performance with a negligible capacity decay of 0.028% per cycle over 2500 cycles. The core–shell design suggested in this study could be extended to other nanomaterials for the optimization of Li–S battery interlayers.