Li Kainan, Zheng Ke, Zhang Zhifang, Li Kuan, Bian Ziyao, Xiao Qian, Zhao Kuangjian, Li Huiyu, Cao Haijing, Fang Zebo, Zhu Yanyan
College of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 200090, People's Republic of China.
School of Materials Science and Engineering, Dongguan University of Technology, Dongguan 523808, People's Republic of China.
Nanotechnology. 2022 Jan 24;33(16). doi: 10.1088/1361-6528/ac487a.
Construction of metal selenides with a large specific surface area and a hollow structure is one of the effective methods to improve the electrochemical performance of supercapacitors. However, the nano-material easily agglomerates due to the lack of support, resulting in the loss of electrochemical performance. Herein, we successfully design a three-dimensional graphene (3DG) encapsulation-protected hollow nanoboxes (CoSe-SnSe) composite aerogel (3DG/CoSe-SnSe) via a co-precipitation method coupled with self-assembly route, followed by a high temperature selenidation strategy. The obtained aerogel possesses porous 3DG conductive network, large specific surface area and plenty of reactive active sites. It could be used as a flexible and binder-free electrode after a facile mechanical compression process, which provided a high specific capacitance of 460 F gat 0.5 A g, good rate capability of 212.7 F gat 10 A gThe capacitance retention rate is 80% at 2 A gafter 5000 cycles due to the fast electron/ion transfer and electrolyte diffusion. With the as-prepared 3DG/CoSe-SnSeas positive electrodes and the AC (activated carbon) as negative electrodes, an asymmetric supercapacitor (3DG/CoSe-SnSe//AC) was fabricated, which delivered a high specific capacity of 38 F gat 1 A gand an energy density of 11.89 Wh kgat 749.9 W kg, as well as excellent cycle stability. This work provides a new method for preparing electrode material.
构建具有大比表面积和中空结构的金属硒化物是提高超级电容器电化学性能的有效方法之一。然而，由于缺乏支撑，这种纳米材料容易团聚，导致电化学性能丧失。在此，我们通过共沉淀法结合自组装路线，随后采用高温硒化策略，成功设计了一种三维石墨烯（3DG）封装保护的中空纳米盒（CoSe-SnSe）复合气凝胶（3DG/CoSe-SnSe）。所获得的气凝胶具有多孔的3DG导电网络、大比表面积和大量的反应活性位点。经过简单的机械压缩过程后，它可以用作柔性无粘结剂电极，在0.5 A g时提供460 F g的高比电容，在10 A g时具有212.7 F g的良好倍率性能。由于快速的电子/离子转移和电解质扩散，在2 A g下经过5000次循环后电容保持率为80%。以制备的3DG/CoSe-SnSe作为正极，活性炭（AC）作为负极，制备了一种非对称超级电容器（3DG/CoSe-SnSe//AC），其在1 A g时具有38 F g的高比容量，在749.9 W kg时能量密度为11.89 Wh kg，并且具有优异的循环稳定性。这项工作为制备电极材料提供了一种新方法。
