Hybrids of MnO2 nanoparticles anchored on graphene sheets as efficient sulfur hosts for high-performance lithium sulfur batteries

• Published in: Journal of solid state electrochemistry 2018-03, Vol.22 (3), p.693-703
• Main Authors: Yuan, Guanghui, Jin, Huafeng, Jin, Yanzi, Wu, Lizhou
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Cathodes; Cathodic dissolution; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Dissolution; Electrical resistivity; Electrochemistry; Energy Storage; Entrapment; Graphene; Lithium sulfur batteries; Manganese dioxide; Original Paper; Physical Chemistry; Polysulfides; Sheets; Sulfur
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-017-3799-5

Lithium–sulfur (Li–S) battery is considered as a promising option for electrochemical energy storage applications because of its low-cost and high theoretical capacity. However, the practical application of Li–S battery is still hindered due to the poor electrical conductivity of S cathode and the high dissolution/shuttling of polysulfides in electrolyte. Herein, we report a novel physical and chemical entrapment strategy to address these two problems by designing a sulfur–MnO 2 @graphene (S–MnO 2 @GN) ternary hybrid material structure. The MnO 2 particles with size of ~ 10 nm are anchored tightly on the wrinkled and twisted GN sheets to form a highly efficient sulfur host. Benefiting from the synergistic effects of GN and MnO 2 in both improving the electronic conductivity and hindering polysulfides by physical and chemical adsorptions, this unique S–MnO 2 @GN composite exhibits excellent electrochemical performances. Reversible specific capacities of 1416, 1114, and 421 mA h g −1 are achieved at rates of 0.1, 0.2, and 3.2 C, respectively. After a 100 cycle stability test, S–MnO 2 @GN composite cathode could still maintain a reversible capacity of 825 mA h g −1 .