Effect of sulfur content in a sulfur-activated carbon composite on the electrochemical properties of a lithium/sulfur battery

•The content of sulfur in activated carbon was controlled by solution process.•The sulfur electrode with low sulfur content shows the best performance.•The Li/S battery has capacity of 1360 mAh/g at 1 C and 702 mAh/g at 10 C.

The content of sulfur in sulfur/activated carbon composite is controlled from 32.37 wt.% to 55.33 wt.% by a one-step solution-based process. When the sulfur content is limited to 41.21 wt.%, it can be loaded into the pores of an activated carbon matrix in a highly dispersed state. On the contrary, when the sulfur content is 55.33 wt.%, crystalline sulfur can be detected on the surface of the activated carbon matrix. The best electrochemical performance can be obtained for a sulfur electrode with the lowest sulfur content. The sulfur/activated carbon composite with 32.37 wt.% sulfur afforded the highest first discharge capacity of 1360 mAh g−1 at 1 C rate and a large reversible capacity of 702 mAh g−1 at 10 C (16.75 A/g).

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide