Effect of lamellar graphite coatings with different thickness on electrochemical properties for lithium-sulfur batteries

Authors：Yang, Xuebing^*; Zhang, Linwei; Yu, Jiuming; Chen, Wenfu; He, Youxing; Lu, Lei

Source：JOURNAL OF SOLID STATE ELECTROCHEMISTRY, 2023, 27(12): 3281-3292.

DOI：10.1007/s10008-023-05611-w

• Lithium-sulfur batteries
• Electrochemical properties
• Sulfur electrode
• Lamellar graphite

Lithium-sulfur batteries possess high theoretical energy density. They are promising in future application. Practical electrochemical performance of lithium-sulfur batteries need to be improved. In this study, a facile approach has been proposed to improve electrochemical properties of lithium-sulfur batteries. Lamellar graphite coatings with different thickness have been prepared on the surface of sulfur electrodes. Morphology of materials has been characterized and electrochemical properties for batteries have been tested. Results indicate that there are cracks on the surface of sulfur electrodes. Lamellar graphite coatings with thickness of 6 & mu;m and 12 & mu;m have uniformly covered surface of sulfur electrodes. Graphite coatings effectively hinder the dissolution of lithium polysulfides and contribute to increase in discharge capacity and retention rate. Thickness of graphite coating affects electrochemical properties of lithium-sulfur batteries. Electrode with 12 & mu;m graphite coating possesses higher discharge capacity and cycle stability than that with 6 & mu;m graphite coating. After 150 cycles, discharge capacity of electrodes with 6 & mu;m and 12 & mu;m graphite coating is 693 mAh g(-1) and 821 mAh g(-1) respectively.