Lithium–sulfur (Li–S) batteries with tremendous energy density possess great promise for the next-generation energy storage devices. Even though, the shuttle effect and sluggish redox kinetics of lithium polysulfides (LiPSs) seriously… Click to show full abstract
Lithium–sulfur (Li–S) batteries with tremendous energy density possess great promise for the next-generation energy storage devices. Even though, the shuttle effect and sluggish redox kinetics of lithium polysulfides (LiPSs) seriously restrict practical applications of Li–S batteries. Herein, a three-dimensionally ordered macro/mesoporous TiN (3DOM TiN) nanostructure is established via using poly (methyl methacrylate) PMMA spheres as template. The interconnected macro/mesoporous channels are constructed to effectively alleviate the stacking of composite materials and render a large portion of inherent active sites exposed on the surface region. Moreover, TiN exhibits high electrical conductivity, which efficiently enhances charge-transfer kinetics and guarantees the favorable electrochemical performance of sulfur cathode. More importantly, the as-prepared 3DOM TiN suppresses the shuttle effect and improves the redox kinetics significantly due to strong affinity toward LiPSs. Attributed to these unique features, the S/3DOM TiN electrode achieves an ultrahigh initial discharge capacity of 1187 mAh g−1 at 0.2 C, and stable cycling performance of 552 mAh g−1 over 500 cycles at 1 C. Meanwhile, the discharge capacity retention of 701 mAh g−1 (3.5 mAh cm−2) can be endowed for the S/3DOM TiN electrode under high sulfur loading of 5 mg cm−2 after 100 cycles at 0.1 C. Therefore, the 3DOM TiN nanostructure electrocatalyst provides a promising path for developing practically useable Li–S batteries.
               
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