Synthesis and electrochemical performance of S/mesoporous carbon microsphere-MoS2 cathode materials
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摘要: 目前锂硫电池的应用仍受活性物质硫和放电产物的绝缘性、中间产物聚硫化物的穿梭以及硫正极在循环过程中较大的体积变化等问题限制。本文以导电中孔炭微球（MCM）为载体材料，将极性的MoS2均匀地负载于MCM框架中，作为高效的硫正极载体材料。结果表明，与MCM/S正极相比，添加了MoS2的MCM/MoS2/S复合正极表现出更高的容量、更好的循环稳定性和倍率性能，其中添加12.4 wt.%的MoS2表现最优异的电化学性能。此外，MoS2在硫正极的工作电压窗口内具有电化学活性，可以提供附加容量，且能在醚系电解液中保持稳定的放电容量。当用MoS2替代部分非电化学活性的载体时，可以提高硫正极的整体容量。这种利用电化学活性的载体提高电极整体容量的思路为进一步提高硫正极的电化学性能提供了参考。Abstract: The commercial uses of Li-S batteries are still greatly limited by a number of obstacles such as the insulating nature of sulfur and its discharge products, the shuttling of intermediate polysulfides and the large volume change of sulfur during cycling. Here, we attached polar MoS2 to a well-developed mesoporous carbon microsphere (MCM) framework and used this as a highly efficient host for the sulfur cathode. Compared with a S/MCM cathode, the S/MCM-MoS2 cathode provided a higher discharge capacity, improved cycling stability and rate performance with an optimum MoS2 content of 12.4 wt.%. MoS2 is electrochemically active within the working voltage range of the sulfur cathode, which contributes extra capacity to the sulfur cathode with a stable cycling performance without loss of capacity in a 1 M LiTFSI electrolyte. The replacement of some of the electrochemically inactive carbon with MoS2 also increases the overall energy density. The exploration of such an electrochemically active host material may provide a new possibility for improving the electrochemical performance of Li-S batteries.
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Key words:
- Mesoporous carbon microsphere /
- Lithium-sulfur battery /
- Sulfur cathode /
- MoS2 /
- Electrochemistry
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Bruce P, Freunberger S, Hardwick L, et al. Li-O2 and Li-S batteries with high energy storage[J]. Nature Materials, 2012, 11(1):19-29. Manthiram A, Chung S, Zu C. Lithium-sulfur batteries:Progress and prospects[J]. Advanced Materials, 2015, 27(12):1980-2006. Seh Z, Sun Y, Zhang Q, et al. Designing high-energy lithium-sulfur batteries[J]. Chemical Society Reviews, 2016, 45(20):5605-5634. Manthiram A, Fu Y, Chung S, et al. Rechargeable lithium-sulfur batteries[J]. Chemical Reviews, 2014, 114(23):11751-11787. 徐朝, 游慧慧, 张磊, 等. 多硫化物阻隔层在锂硫电池中的应用研究进展[J]. 新型炭材料, 2017, 32(2):97-105. (Xu Z, You H, Zhang L, et al. Recent development of polysulfide barriers for Li-S batteries[J]. New Carbon Mateials, 2017, 32(2):97-105.) Su Y, Manthiram A. Sulfur/lithium-insertion compound composite cathodes for Li-S batteries[J]. Journal of Power Sources, 2014, 270:101-105. Ma L, Wei S, Zhuang H, et al. Hybrid cathode architectures for lithium batteries based on TiS2 and sulfur[J]. Journal of Materials Chemistry A, 2015, 3(39):19857-19866. Zhou J, Wang Y, Wang J, et al. Effective removal of hexavalent chromium from aqueous solutions by adsorption on mesoporous carbon microspheres[J]. Journal of Colloid and Interface Science, 2016, 462:200-207. Sun F, Wei Y, Chen J, et al. Melamine-assisted one-pot synthesis of hierarchical nitrogen-doped carbon@MoS2 nanowalled core-shell microspheres and their enhanced Li-storage performances[J]. Nanoscale, 2015, 7(30):13043-13050. Schuster J, He G, Nazar F, et al. Spherical ordered mesoporous carbon nanoparticles with high porosity for lithium-sulfur batteries[J]. Angewandte Chemie International Edition, 2012, 124, 3651-3655. Sun F, Wang J, Long D, et al. A high-rate lithium-sulfur battery assisted by nitrogen-enriched mesoporous carbon decorated with ultrafine La2O3 nanoparticles[J]. Journal of Materials Chemistry A, 2013, 1, 13283. Sun W, Ou XG, Sun K, et al. A simply effective double-coating cathode with MnO2 nanosheets/graphene as functionalized interlayer for high performance lithium-sulfur batteries[J]. Electrochimica Acta, 2016, 207, 198-206. Qu Q, Gao T, Shao J, et al. Strong surface-bound sulfur in conductive MoO2 matrix for enhancing Li-S batteries performance[J]. Advanced Materials Interfaces, 2015, 2, 1500048. Jayaprakash N, Shen J, Moganty S, et al. Porous hollow carbon@sulfur composites for high-power lithium-sulfur batteries[J]. Angewandte Chemie International Edition, 2011, 123(26):6026-6030. Li Z, Jiang Y, Yuan L, et al. A highly ordered meso@microporous carbon-supported sulfur@smaller sulfur core-shell structured cathode for Li-S batteries[J]. ACS Nano, 2014, 8(9):9295-9303. Ahn W, Seo M, Jun Y, et al. Sulfur nanogranular film-coated three-dimensional graphene sponge-based high power lithium sulfur battery[J]. ACS Applied Materials & Interfaces, 2016, 8(3):1984-1991. Zhang Q, Wang Y, Seh Z, et al. Understanding the anchoring effect of two-dimensional layered materials for lithium-sulfur batteries[J]. Nano Letters, 2015, 15(6):3780-3786. Qu Q, Gao T, Zheng H, et al. Strong surface-bound sulfur in conductive MoO2 matrix for enhancing Li-S battery performance[J]. Advanced Materials Interfaces, 2015, 2:1500048. Wang H, Tsai C, Cui Y, et al. Transition-metal doped edge sites in vertically aligned MoS2 catalysts for enhanced hydrogen evolution[J]. Nano Research, 2015, 8(2):566-575. Chhowalla M, Shin H, Eda G, et al. The chemistry of two-dimensional layered transition metal dichalcogenide nanosheets[J]. Nature Chemistry, 2013, 5(4):263-275. -
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