Li-S battery with high theoretical capacity and energy density has been viewed as a promising choice of the next-generation energy storage devices. One of the main problems that restricts the large scale application of Li-S battery is the sluggish kinetics of lithium polysulfide (LiPS) redox conversion and the rapid capacity decay caused by LiPS migration. In this study, a novel two-dimensional carbon-based material with abundant atomically dispersed Mo-N-C active sites was synthesized and employed as a high-performance sulfur host. The Mo-N/C nanoplates with high pore volume and metal utilization can accomodate more sulfur than commonly used metal/carbon composite, which promises a high sulfur content S/Mo-N/C composite. Thanks to the unique structure and atomically dispersed Mo-N/C sites, the S/Mo-N/C cathode delivers high initial capacities of 1392 mAh g<sup>-1</sup> and 520 mAh g<sup>-1</sup> at at 0.1 C and 5 C, respectively. When conducted in long-term cycling tests, the S/Mo-N/C cathode holds a 95% capacity retention after 200 cycles under 1 C and 77% retention after 800 cycles under 10 C (0.028% decay per cycle). Such high rate performance and cycling stability are attributed to the excellent electrocatalytic activity of Mo-N/C material in LiPS conversion.

Atomically dispersed Mo-N/C as high performance sulfur host in Li-S battery

2019 Spring National Meeting

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