Synergistic effects of reduced graphene oxide with freeze drying tuned interfacial structure on performance of transparent and flexible supercapacitors

Yi He; Xin Zhang; Yuxiang Zhong; Xue Li; Lailei Wu; Hanyu Liu; Huiyang Gou; Gongkai Wang

doi:10.1016/j.jcis.2019.07.050

Synergistic effects of reduced graphene oxide with freeze drying tuned interfacial structure on performance of transparent and flexible supercapacitors

J Colloid Interface Sci. 2019 Oct 15:554:650-657. doi: 10.1016/j.jcis.2019.07.050. Epub 2019 Jul 20.

Authors

Yi He¹, Xin Zhang¹, Yuxiang Zhong¹, Xue Li², Lailei Wu³, Hanyu Liu², Huiyang Gou⁴, Gongkai Wang⁵

Affiliations

¹ School of Material Science and Engineering, Research Institute for Energy Equipment Materials, Hebei University of Technology, Tianjin 300130, China; Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology, Hebei University of Technology, Tianjin 300130, China.
² State Key Laboratory of Superhard Materials & Innovation Center for Computational Physics Methods and Software, College of Physics, 130012, Jilin University, China.
³ Clean Nano Energy Center, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China.
⁴ Center for High Pressure Science and Technology Advanced Research, Beijing 100190, China.
⁵ School of Material Science and Engineering, Research Institute for Energy Equipment Materials, Hebei University of Technology, Tianjin 300130, China; Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology, Hebei University of Technology, Tianjin 300130, China. Electronic address: wang.gongkai@hebut.edu.cn.

PMID: 31351335
DOI: 10.1016/j.jcis.2019.07.050

Abstract

Transparent and flexible supercapacitors (TFSCs) could diversify the future wearable electronics owing to the fascinating optoelectronic and electrochemical performances. Herein, we report symmetric TFSCs assembled by reduced graphene oxide (rGO)@Ag nanowire/poly (ethylene terephthalate) (PET) transparent electrodes for capacitive storage, in which the interfacial structure of rGO film can be tuned by a facile freeze drying technique. The enlarged interlayer spacing of rGO film deteriorated the electronic migration derived from the loose layer structure, whereas about 33-52% of the areal capacitance of TFSCs was boosted as compared with the ones without freeze drying at the same transmittance. It is concluded that the enlarged inter-distance of rGO film could facilitate diffusion and transport of ions in the electrolyte, furthermore, the expanded rGO film could provide more interface to accommodate more ions for storage. The simulation results also confirmed the lower diffusion barrier and larger band gap of rGO with larger interlayer distance. The mechanically robust TFSCs exhibit the maximum energy density of 89.2 nWh cm^-2, and the maximum power density of 4.63 μW cm^-2 with remaining energy density of 41.1 nWh cm^-2, as well as 3000 cyclic stability, demonstrating an efficient strategy toward high performance TFSCs.

Keywords: Flexible supercapacitors; Freeze drying; Interfacial structure; Reduced graphene oxide; Transparent supercapacitors.