Department of Chemistry, Duke University , Durham, North Carolina 27708, United States.
ACS Appl Mater Interfaces. 2017 Aug 2;9(30):25232-25238. doi: 10.1021/acsami.7b04321. Epub 2017 Jul 24.
Selenium (Se) has great promise to serve as cathode material for rechargeable batteries because of its good conductivity and high theoretical volumetric energy density comparable to sulfur. Herein, we report the preparation of mesoporous nitrogen-doped carbon scaffolds (NCSs) to restrain selenium for advanced lithium-selenium (Li-Se) batteries. The NCSs synthesized by a bottom-up solution-phase method have graphene-like laminar structure and well-distributed mesopores. The unique architecture of NCSs can severe as conductive framework for encapsulating selenium and polyselenides, and provide sufficient pathways to facilitate ion transport. Furthermore, the laminar and porous NCSs can effectively buffer the volume variation during charge/discharge processes. The integrated composite of Se-NCSs has a high Se content and can ensure the complete electrochemical reactions of Se and Li species. When used for Li-Se batteries, the cathodes based on Se-NCSs exhibit high capacity, remarkable cyclability, and excellent rate performance.
硒（Se）具有很大的潜力作为可充电电池的阴极材料，因为它具有良好的导电性和与硫相当的高理论比体积能量密度。在此，我们报告了介孔氮掺杂碳支架（NCSs）的制备，以抑制用于先进的锂-硒（Li-Se）电池中的硒。通过自下而上的溶液相方法合成的 NCSs 具有类石墨烯层状结构和均匀分布的介孔。NCSs 的独特结构可以作为封装硒和多硒化物的导电骨架，并提供足够的途径来促进离子传输。此外，层状和多孔 NCSs 可以有效缓冲充放电过程中的体积变化。Se-NCSs 的整体复合材料具有高的硒含量，并能保证硒和锂离子的完全电化学反应。当用于 Li-Se 电池时，基于 Se-NCSs 的正极具有高容量、显著的循环稳定性和优异的倍率性能。
