Search

Hollow graphene spheres are successfully prepared and employed as the separator coating materials for lithium-sulfur batteries. The hollow graphene spheres coated separator has been proven an efficient trap to adsorb and block polysulfide, greatly alleviating the shuttle effect. In the case of using elemental sulfur as cathode active material and the weight of the diaphragm is only increased by 10.3%, the lithium-sulfur battery with hollow graphene spheres coated separator delivers a high initial specific capacity of 1172.3 mAh g−1 at the current density of 0.2 C, and the discharge capacity remains at 829.6 mAh g−1 after 200 cycles with a capacity decay of 0.146% per cycle, showing excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

Li–S battery is considered as one of the most competitive energy storage devices mainly due to the high theoretical specific capacity and high specific energy. However, when facing with the practical application, some issues, especially poor electro-conductivity of element sulfur and severe polysulfides (LiPSs) migration, are still needed to solve to further improve the performance of the Li–S batteries. Aiming at the above two disadvantages, in this work, multifunctional separators are designed as efficient LiPSs absorber via coating vapor grown carbon fiber/MoS 2 (VGCF/MoS 2) composites on the polypropylene separator (PP) near the cathode side. For the as-prepared VGCF/MoS 2 coated polypropylene separator (VM/PP), MoS 2 could provide strong chemical adsorption for the LiPSs, while the VGCF framework could act as an electronic transmission channel for the conversion of LiPSs, and also provide physical adsorption for LiPSs at the same time. Benefit from these characteristics, the batteries with VM/PP exhibits a high initial capacity of 1208.7 mAh g−1 at 0.2C and maintains at 862.4 mAh g−1 after 200 cycles. Impressively, the VM/PP shows the high specific capacity of 904.3 mAh g−1 and long-lasting cycling stability with 0.03% capacity attenuation per cycle over 600 cycles at 1.0C, demonstrating excellent electrochemical performance. [ABSTRACT FROM AUTHOR]