Flexible TiC modified separators trapping polysulfide for high performance lithium–sulfur batteries

Abstract

Owing to their unique properties, titanium carbide (TiC) can be employed in wide-ranging fields, including preparing semiconductor separator and surface modifying and other areas. However, there are no works about the employment of TiC in the energy storage systems, especially in lithium-sulfur batteries. As we all know, the severe polysulfide migration limited the practical application of the lithium-sulfur batteries. It is significant to inhibit the shuttle effect of the soluble polysulfide in the electrolyte. Therefore, in the present work, a novel TiC modified PP (TC@PP) separator was prepared and used to improve the electrochemical performance of the lithium-sulfur batteries. The morphology and the structure of the TiC ceramics were firstly characterized by XRD, SEM, XPS. After that, the wettability and adsorption properties of the TC@PP separator were observed via contact angle and permeation tests. Compared with the pristine PP separator, the TC@PP separator exhibited superior wettability and adsorption ability for the polysulfide. As a result, the batteries with TC@PP separator displayed high specific capacity and stable cycling performance.