Selenium Embedded in Metal-Organic Framework Derived Hollow Hierarchical Porous Carbon Spheres for Advanced Lithium-Selenium Batteries
Selenium Embedded in Metal-Organic Framework Derived Hollow Hierarchical Porous Carbon Spheres for Advanced Lithium-Selenium Batteries
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DOI：
10.1021/acsami.6b04060
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发表时间：
2016-06-29
影响因子：
9.5
通讯作者：
Li, Chang Ming
中科院分区：
文献类型：
--
作者：
Liu, Ting;Dai, Chunlong;Li, Chang Ming
采用简单的水热法结合后续退火处理制备了金属有机骨架衍生的中空分层多孔碳球。这种MHPCS是由大量大小约为20nm的空心小碳泡和厚度为nm的壳相互连接而成的。MHPCS/Se复合材料被开发为锂硒电池的阴极，在0.5 C的电流密度下提供高达588.2 mA h g（-1）的初始比容量，在500次循环中表现出出色的循环稳定性，每个循环的衰减率甚至降至0.08%。这种材料在电流密度为1 c的情况下，即使在1000次循环后仍能保持高达200 mA h g（-1）的电流。这种良好的电化学性能可能归因于碳球独特的中空结构和大量的Se包裹在小碳泡中，从而不仅增强了电子/离子传输，而且在充放电过程中提供了额外的缓冲空间来调节Se的体积变化。
Metal-organic framework derived hollow hierarchical porous carbon spheres (MHPCS) have been fabricated via a facile hydrothermal method combined with a subsequent annealing treatment. Such MHPCS are composed of masses of small hollow carbon bubbles with a size of similar to 20 nm and shells of nm thickness interconnected to each other. MHPCS/Se composite is developed as a cathode for Li-Se cells and delivers an initial specific capacity up to 588.2 mA h g(-1) at a current density of 0.5 C, exhibiting an outstanding cycling stability over 500 cycles with a decay rate even down to 0.08% per cycle. This material is capable of retaining up to 200 mA h g(-1) even after 1000 cycles at a current density of 1 C. Such good electrochemical performance may be ascribed to the distinct hollow structure of the carbon spheres and a large amount of Se wrapped within small carbon bubbles, thus not only enhancing the electronic/ionic transport but also providing additional buffer space to adjust volume changes of Se during charge/discharge processes.