Institute for Clean Energy and Advanced Materials, Faculty of Materials and Energy, Southwest University , Chongqing 400715, P.R. China.
Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Chongqing 400715, P.R. China.
ACS Appl Mater Interfaces. 2017 Nov 29;9(47):41339-41346. doi: 10.1021/acsami.7b14380. Epub 2017 Nov 16.
The substitution of Se for S as cathode for rechargeable batteries, which confine selenium in porous carbon, attracts much attention as a potential area of research for energy storage systems. To date, there are no reports about metal-organic frameworks (MOFs) to use for Na-Se batteries. Herein, MOFs-derived nitrogen-doped porous carbon polyhedrons (NPCPs) have been obtained via facile synthesis and annealing treatment. Se is encapsulated into the mesopores of carbon polyhedrons homogeneously by melt-diffusion process to form Se/NPCPs composite, using as cathode for advanced Na-Se batteries. Se/NPCPs cathode exhibits excellent rate capabilities of 351.6 and 307.8 at 0.5C and 2C, respectively, along with good cycling performance with high Coulombic efficiency of 99.7% and slow decay rate of 0.05% per cycle after 1000 cycles at 2C, which result from the NPCPs having a unique porous structure to accommodate volumetric expansion of Se during discharge-charge processes. Nitrogen doping could enhance the electrical conductivity of carbon matrix and facilitate rapid charge transfer.
硒替代硫作为可充电电池的阴极，将硒限制在多孔碳中，作为储能系统的一个潜在研究领域引起了广泛关注。迄今为止，还没有关于用于钠-硒电池的金属-有机框架（MOFs）的报道。在此，通过简便的合成和退火处理，得到了 MOFs 衍生的氮掺杂多孔碳多面体（NPCPs）。通过熔融扩散过程，硒均匀地封装在碳多面体的介孔中，形成 Se/NPCPs 复合材料，用作先进的 Na-Se 电池的阴极。Se/NPCPs 阴极在 0.5C 和 2C 时分别具有 351.6 和 307.8 的出色倍率性能，并且在 2C 下循环 1000 次后具有高库仑效率 99.7%和缓慢衰减率 0.05%/循环的良好循环性能，这是由于 NPCPs 具有独特的多孔结构，可以容纳硒在放电-充电过程中的体积膨胀。氮掺杂可以提高碳基质的导电性并促进快速电荷转移。
