S@CNT-graphene-TiN multi-dimensional composites with high sulfur content as the high-performance lithium-sulfur battery cathode materials

摘要

S@CNT-G-TiN multi-dimensional composite materials with above 90 wt.% sulfur content were successfully synthesized via a facile suspension deposition method. The as-prepared S@CNT-G-TiN composite materials delivered an excellent initial specific capacity of 1291 and 642 mAh/g at 0.1 C and 3 C, respectively. The S@CNT-G-TiN cathode with 7.5 mg/cm(2) sulfur loading exhibited a reversible areal capacity of 7.7 mAh/cm(2) after 100 cycles, which proved that the S@CNT-G-TiN cathode was favored for the construction of high sulfur loading Li-S batteries. The superior electrochemical performance could be attributed to the specific CNT-G-TiN host, which provide a conductive network in the electrode and suppress the shuttle effect of lithium polysulfides (LiPSs). 5 Ah Li-S pouch cell was also fabricated by using the S@CNT-G-TiN cathode, which exhibited high-energy density of 401 Wh/kg and retained a stable cycling performance with an average capacity fading of 0.2% per cycle after 50 cycles, indicating the potential applications of S@CNT-G-TiN composite materials in high-performance Li-S batteries.