Decoration of indium tin oxide nanoparticles with different crystal structures and morphologies on polypropylene separator for Li‐S battery

Abstract

A variety of materials have been applied for the modification of cathode or separator for lithium-sulfur batteries so as to overcome the intrinsic problems of lithium-sulfur batteries. Here, indium tin oxide with different crystal structures and morphologies has been used for the modification of commercial polypropylene (PP) separators for lithium-sulfur batteries to prohibit the polysulfides shuttle and promote the Li-S cell performances. Indium tin oxide with cubic bixbyite (c-ITO) and hexagonal corundum (h-ITO) are firstly fabricated by different hydrothermal reactions and then coated on PP separator to obtain c-ITO@PP and h-ITO@PP separators. Then, c-ITO@PP and h-ITO@PP separators are used in Li-S coin cells to improve the electrochemical properties. The experimental data suggest that the cells equipped with c-ITO@PP or h-ITO@PP modified separator exhibit better electrochemical performances than the cell with unmodified PP separator and super P modified separator, which demonstrate that the c-ITO and h-ITO show better polysulfides adsorption ability than the pure carbon materials. Furthermore, the cycle retention of the Li-S cell using h-ITO@PP separator is superior than that of the one using c-ITO@PP separator. This result is supposed to be mainly induced by the more oxygen vacancies in h-ITO which is proved by the X-ray photoelectron spectroscopy study, and the UV-vis spectroscopy of Li 2 S 6 adsorption further demonstrate the better polysulfides adsorption ability of h-ITO.

Minimizing Carbon Content with Three‐in‐One Functionalized Nano Conductive Ceramics: Toward More Practical and Safer S Cathodes of Li‐S Cells

“…Moreover, they have a typical size less than 10 nm (even smaller than 30 nm carbon black (CB) powders) and a large surface‐to‐volume ratio; thereby, ample adsorption sites would be exposed, facilitating the deposition/nucleation of solid Li 2 S 2 /Li 2 S and suppressing LiPS shuttling. [ 27 ] The ultrafine property of ITO also benefits dispersing S actives and polymer binders in slurries to form homogeneous/adhesive films on Al current collectors. Third, partial doped In atoms may interact with LiPS to form metastable intermediates, [ 28 ] catalytically accelerating the liquid–solid phase conversions for S‐based actives and hence retarding LiPS shulttling.…”