Three-dimensional graphene encapsulated hollow CoSe2-SnSe2 nanoboxes for high performance asymmetric supercapacitors. (16th April 2022)

• Record Type: Journal Article
• Authors: Li, Kainan; Zheng, Ke; Zhang, Zhifang; Li, Kuan; Bian, Ziyao; Xiao, Qian; Zhao, Kuangjian; Li, Huiyu; Cao, Haijing; Fang, Zebo; Zhu, Yanyan
• Is Part Of: Nanotechnology. Volume 33:Number 16(2022)
• Publication Date: 2022-04-16
• Subjects: hollow CoSe2-SnSe2 nanoboxes -- graphene encapsulated -- reaction kinetics; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/ac487a
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: 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 (CoSe2 -SnSe2 ) composite aerogel (3DG/CoSe2 -SnSe2 ) 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 g –1 at 0.5 A g –1, good rate capability of 212.7 F g −1 at 10 A g −1 The capacitance retention rate is 80% at 2 A g −1 after 5000 cycles due to the fast electron/ion transfer and electrolyte diffusion. With the as-prepared 3DG/CoSe2 -SnSe2 as positive electrodes and the AC (activated carbon) as negative electrodes, an asymmetric supercapacitor (3DG/CoSe2 -SnSe2 //AC) was fabricated, which delivered a high specific capacity of 38 F g –1 at 1 A g –1 and an energy density of 11.89 Wh kg −1 at 749.9 W kg –1, as well as excellent cycle stability. This work provides a new method for preparing electrode material.