Current Status and Prospect of Cathode Materials for Lithium Sulfur Batteries

Abstract

Elemental sulfur has been extensively investigated as a promising candidate of cathode material for next generation lithium secondary batteries. However, some troublesome issues, such as the low electric conductivity of sulfur(5×10-30S·cm-1) and the high solubility of lithium polysulfide intermediates in organic electrolytes, resulting in a low utilization of active material and a redox shuttling of dissolved polysulfide ions between the sulfur cathode and the lithium anode, which eventually leads to a deposition of insoluble and insulating Li2S2/Li2 S on the electrode surface and a fast reduction in the specific capacity. Notably, recent results indicate that carbon materials have been regarded as the ideal matrix for sulfur to improve the discharge capacity and cycling performance of lithium-sulfur batteries. In this review, recent development of carbon materials for lithium sulfur batteries is summarized and the prospect on sulfur/carbon composites cathode is discussed.