Strutted graphene foam loading sulfur for high-rate long-lifetime Li-S batteries
Fanyu Zhou, Yuhang Meng, Tao Wang, Dandan Sun, Lei Gao, Zhipeng Sun, Yueqi Wang, Jinjue Zeng, Baolu Wang, Ran Zhang, Ruiqing Li, Chaobo Huang, Lijun Yang, Xuebin Wang
Abstract
Lithium-ion (Li-ion) batteries are currently limited by the capacity and cost of conventional Li-intercalated cathodes. Lithium-sulfur (Li-S) batteries, with high theoretical capacity of sulfur cathode and low cost, have been considered as one of the most promising next-generation batteries. Nevertheless, the application of Li-S batteries is hampered by limited rate and cycle capability stemming from the low conductivity, volume expansion of the sulfur cathode, and the shuttle effect of polysulfides . In this study, a strutted graphene (SG) foam is developed with interconnected networks, rich porous structures, and stable defects, as a sulfur host directly for Li-S battery. This SG foam improves conductance of cathodes, relieves volume change, facilitates electron and ion transports, and inhibits the shuttle effect. As a result, the sulfur-loaded SG cathode demonstrates excellent performances, with a capacity of 1442 mAh g −1 at 0.2 C, a high-rate capacity of 857 mAh g −1 at 4 C, and the cyclability with a capacity of 691 mAh g −1 after 500 cycles at 2 C. It thus provides an effective host for cathodes for Li-S batteries.