High Volumetric Energy Density Asymmetric Fibrous Supercapacitors with Coaxial Structure Based on Graphene/MnO2 Hybrid Fibers. Issue 22 (19th November 2020)

• Record Type: Journal Article
• Authors: Wu, Guiqing; Yang, Xinyu; Hou, Chengyi; Li, Yaogang; Zhang, Qinghong; Wang, Hongzhi
• Is Part Of: ChemElectroChem. Volume 7:Issue 22(2020)
• Page Start: 4641
• Page End: 4648
• Publication Date: 2020-11-19
• Subjects: graphene fiber -- fibrous supercapacitors -- asymmetric supercapacitors -- coaxial supercapacitors -- volumetric energy density; Electrochemistry -- Periodicals; 541.37
• DOI: 10.1002/celc.202001139
• Languages: English
• ISSNs: 2196-0216

Abstract

Abstract: In order to improve the performance of the fibrous supercapacitors to be more suitable for practical application, we prepared graphene/MnO2 hybrid fibers by doping MnO2 nanorods into graphene fibers through a simple wet spinning method, in which MnO2 act as the pseudocapacitive materials. This hybrid fiber electrode shows a wide potential window of −0.2–1 V and a high volume specific capacitance of 473 F cm −3 . Based on these hybrid fibers, we fabricated asymmetric fibrous supercapacitors with coaxial structure. In the coaxial device, the internal electrode is graphene/MnO2 hybrid fiber, while the external electrode is graphene coated by dip coating method. The volume specific capacitance and the volumetric energy density of the coaxial device reaches up to 24 F cm −3 and 8.44 mWh cm −3, respectively, 200 % higher than these of the twisting device. The coaxial structure had not only decreased the charge transfer resistance between the two electrodes, but also increased the volume utilization rate of the devices. Therefore, this type of high volumetric energy density asymmetric fibrous supercapacitors has a wide range of applications in portable and flexible electronics and intelligent fabrics. Abstract : Full of fiber : An asymmetric fibrous supercapacitor with coaxial structure based on graphene/MnO2 hybrid fibers is fabricated. Due to the redox action between MnO2 nanorods and electrolyte, the small volume and the low charge transfer resistance, this fibrous supercapacitor showed a high volumetric energy density of 8.44 mWh cm −3 .