5 years ago

Lithiation-Assisted Strengthening Effect and Reactive Flow in Bulk and Nanoconfined Sulfur Cathodes of Lithium–Sulfur Batteries

Lithiation-Assisted Strengthening Effect and Reactive Flow in Bulk and Nanoconfined Sulfur Cathodes of Lithium–Sulfur Batteries
Shangchao Lin, Jingui Yu, Mingchao Wang
Lithiation of electrode materials can lead to significant microstructural evolution and changes in their mechanical behaviors in lithium batteries. Lithium–sulfur (Li–S) batteries have recently attracted extensive attention, where carbon matrices have been utilized to retain S content by restricting the dissolution of polysulfide into electrolytes. Here we systematically investigate S cathode upon unconfined and nanoconfined lithiation using reactive molecular dynamics simulations. We demonstrate the great ductility of lithiated amorphous S cathode (a-LixS) governed by overcoordination sites, as well as the resulting strengthening effect of a-LixS due to the formation of stronger Li–S bonds upon lithiation. Fracture and cavitation studies also indicate the dominant role of shear banding, which is facilitated by overcoordinated S “plastic carriers”, in accommodating the plastic deformation of a-LixS under tensile loading. Based on a chemo-mechanical yield function, we confirm two-dimensionally nanoconfined lithiation reaction can facilitate the out-of-plane inelastic deformation (“reactive flow”) of a-LixS at a much lower level of biaxial stress. The atomistic understanding of lithiation behaviors of S cathodes provides fundamental insight into the optimal design of carbon-based S composite cathode with outstanding mechanical integrity, as well as the prediction of lithiation behavior of other electrode materials, such as silicon, metal oxides, and graphite.

Publisher URL: http://dx.doi.org/10.1021/acs.jpcc.7b05446

DOI: 10.1021/acs.jpcc.7b05446

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.