Hollow TiO2 spheres wrapped in graphene nanosheets as advanced polysulfide barrier for superior electrochemical performance lithium-sulfur batteries

• Published in: Ionics 2020-12, Vol.26 (12), p.6119-6124
• Main Author: Han, Jianmei
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Composite materials; Condensed Matter Physics; Electrochemical analysis; Electrochemistry; Energy Storage; Flux density; Graphene; Lithium; Lithium sulfur batteries; Nanosheets; Optical and Electronic Materials; Original Paper; Polysulfides; Renewable and Green Energy; Storage batteries; Storage systems; Sulfur; Titanium dioxide
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-020-03771-7

To meet the increasing demands of electric applications, lithium-sulfur batteries are promising energy storage systems due to their high specific capacity and energy density. However, some obstacles still hinder the practical use of lithium-sulfur batteries, which are mainly caused by the poor electronic conductivity and polysulfide migration. To deal with these problems, hollow TiO 2 spheres wrapped in graphene (HTOS/G) composites are developed and used as host materials for sulfur particles. Due to the synthetic effect of improving electronic conductivity and inhibiting the polysulfide migration by employing HTOS/G as host materials, the as-prepared HTOS/G-S composites exhibit high specific capacity and excellent cycling stability. The initial specific capacity is as high as 1263 mAh g −1 at 0.1C. The HTOS/G-S composites display high capacity retention of 87.8% after 300 cycles at the current density of 2C.