MnO2 nanosheets grown on the internal/external surface of N-doped hollow porous carbon nanospheres as the sulfur host of advanced lithium-sulfur batteries
MnO2 nanosheets grown on the internal/external surface of N-doped hollow porous carbon nanospheres as the sulfur host of advanced lithium-sulfur batteries
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DOI：
10.1016/j.cej.2017.11.039
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发表时间：
2018-03-01
影响因子：
15.1
通讯作者：
Wu, Yuting
中科院分区：
文献类型：
--
作者：
Chen, Manfang;Lu, Qun;Wu, Yuting
纳米结构多孔碳材料被广泛用作硫主体材料，以提高硫的利用率并改善锂硫电池的电性能。然而，由于具有均匀非极性表面的纳米碳与固有极性硫客体之间的界面不相容性，正极材料在长期循环过程中仍然面临着较差的稳定性。在此，基于高效的硫主体，即在氮掺杂中空多孔碳纳米球（NHCSs@MnO2）两侧生长的氧化锰纳米片，我们提出了一种合理的物理和化学双重封装策略，用于先进的锂硫电池的应用。多功能、集成和空心杂化纳米球可以提供有效的电子修饰界面，容纳更多的活性材料，重要的是面对面通过协同限制有效防止多硫化物溶解和扩散，因此开发的NHCSs@MnO2/S复合材料在0.5 C下表现出1249 mAh g(-1)的初始放电容量和可持续的循环稳定性，在1000次循环中每个循环的容量衰减仅为0.041%。这意味着其作为先进锂硫电池在改善循环性能和电化学性能方面的巨大应用前景。
Nanostructured porous carbon materials are widely used as sulfur host materials in order to enhance sulfur utilization and improve electrical performance in Li-S batteries. However, owing to interface incompatibility between the nanocarbon with homogeneous nonpolar surface and intrinsic polar sulfur guests, the cathode materials still face poor stability during the long-term cycling process. Herein, based on a highly effective sulfur host, namely manganese oxide nanosheets grown on both sides of the N-doped hollow porous carbon nanospheres (NHCSs@MnO2), we put forward a rational physical and chemical dual-encapsulation strategy for the application of advanced Li-S batteries. The multifunctional, integrated and hollow hybrid nanospheres can provide efficient electron-modified interface, hold much more active material, and importantly face-to-face effectively prevent polysulfide dissolution and diffusion via the synergistic restriction, thus the developed NHCSs@MnO2/S composite exhibits an initial discharge capacity of 1249 mAh g(-1) at 0.5 C and a sustainable cycling stability with ultralow capacity decay of only 0.041% per cycle over 1000 cycles, implying its great prospects for the improved cyclability and electrochemical performance as application of advanced Li-S battery.