Lithium-sulfur (Li-S) batteries are considered a promising energy storage solution for today's society, which faces significant energy and environmental issues. Successful implementation of Li-S batteries requires the development of a robust and high-performance sulfur cathode. Unfortunately, the current approaches focus on the development of sulfur-carbon composites without a fundamental understanding of the reduction mechanism of sulfur and the role of carbon. To develop a clear understanding of the efficacy of carbon/sulfur composites, we investigated the electrochemical behavior of Li-S batteries employing different cathode structures. Our comparative study suggests that nanoscale electrical contact between sulfur and carbon is not essential for improving the electrochemical performance of Li-S batteries or for initiating electrochemical redox reactions of the sulfur cathode. (C) 2016 Elsevier Ltd. All rights reserved.