Lv Li-Ping, Zhi Chuanwei, Gao Yun, Yin Xiaojie, Hu Yiyang, Crespy Daniel, Wang Yong
School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444, P. R. China.
Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand.
Nanoscale. 2019 Aug 7;11(29):13996-14009. doi: 10.1039/c9nr03088c. Epub 2019 Jul 16.
This work reports hierarchical "tube-on-fiber" nanostructures, composed of carbon nanotubes (CNTs) on carbon nanofibers (CNFs), impregnated with mixed-metal selenide nanoparticles (Co-Zn-Se@CNTs-CNFs), as high performance supercapacitors. Co-Zn hybrid zeolitic imidazolate framework-67 (Co-Zn ZIF-67) was electrospun with polyacrylonitrile (PAN) to form nanofibers that were sequentially thermally treated and subjected to selenylation. The "tube-on-fiber" structure is designed to confine the Co-Zn mixed-metal selenide nanoparticles and prevents their agglomeration. Extruded CNTs rooting in carbon nanofibers further improve the electronic conductivity. The mixed-metal selenide allows more accommodation space and faradic reactions compared to single metal selenide. Based on these merits, the hierarchical Co-Zn-Se@CNTs-CNFs exhibit a high specific capacity of 1040.1 C g (1891 F g) at 1 A g with impressive rate performance in supercapacitors. Furthermore, a hybrid supercapacitor with Co-Zn-Se@CNTs-CNFs as the cathode and porous carbon nanofibers as the anode (denoted as Co-Zn-Se@CNTs-CNFs//PCNFs) is fabricated. It delivers a superior energy and power density of 61.4 W h kg and 754.4 W kg, respectively, and meanwhile retains 31.7 W h kg of the energy density with 15 421.6 W kg of the working power. In addition, the assembled supercapacitor device displays an excellent capacity retention of 88.6% after 8000 cycles at 5 A g.
这项工作报道了一种由碳纳米纤维（CNF）上的碳纳米管（CNT）组成的分层“管上纤维”纳米结构，其浸渍有混合金属硒化物纳米颗粒（Co-Zn-Se@CNTs-CNFs），作为高性能超级电容器。将Co-Zn混合沸石咪唑酯骨架-67（Co-Zn ZIF-67）与聚丙烯腈（PAN）进行静电纺丝以形成纳米纤维，然后依次进行热处理和硒化处理。“管上纤维”结构旨在限制Co-Zn混合金属硒化物纳米颗粒并防止其团聚。扎根于碳纳米纤维中的挤出碳纳米管进一步提高了电子导电性。与单一金属硒化物相比，混合金属硒化物具有更多的容纳空间和法拉第反应。基于这些优点，分层的Co-Zn-Se@CNTs-CNFs在1 A g下表现出1040.1 C g（1891 F g）的高比容量，在超级电容器中具有令人印象深刻的倍率性能。此外，制备了一种以Co-Zn-Se@CNTs-CNFs为阴极、多孔碳纳米纤维为阳极的混合超级电容器（表示为Co-Zn-Se@CNTs-CNFs//PCNFs）。它分别提供了61.4 W h kg和754.4 W kg的优异能量和功率密度，同时在15421.6 W kg的工作功率下保留了31.7 W h kg的能量密度。此外，组装的超级电容器装置在5 A g下循环8000次后显示出88.6%的优异容量保持率。
