Synthesis and characterization of graphene/carbonized paper/tannic acid for flexible composite electrodes

• Published in: New journal of chemistry Vol. 42; no. 17; pp. 14576 - 14585
• Main Authors: Jia, Meng-Ying, Xu, Lan-Shu, Li, Yue, Yao, Chun-Li, Jin, Xiao-Juan
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 2018
• Subjects: Acids; Additives; Capacitance; Carbonization; Electrode materials; Electrodes; Energy storage; Flux density; Graphene; Ion transport; Maximum power density; Nanotubes; Porosity; Sheets; Tannic acid; Vacuum filtration
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/c8nj02898b

A simple and low-cost approach toward flexible and free-standing electrodes is developed. Ternary composites of graphene/carbonized paper/tannic acid (GN/CP/TA) with various ratios were fabricated via a facile vacuum-filtration process. Through carbonization of widely used paper, the obtained carbonized paper possessed a good pore structure and an ion transport channel. Tannic acid (TA) can enter into the layers of graphene sheets and prevent graphene sheets from agglomerating by suppressing the π-π stacking interactions. Different amounts of tannic acid increased the distance between graphene sheets, facilitating the formation of GN/CP/TA composite electrodes without metallic current collectors, binders and additives. The optimal ratio (GN/CP/TA 2 ) was determined and the composite electrodes displayed a high area specific capacitance of 530.2 mF cm −2 with a mass of 2.85 mg cm −2 (specific capacitance of 186 F g −1 ) at 0.2 mA cm −2 . The composite electrode had good mechanical flexibility (about 82.94% retention in capacitance after 500 bending times) and prominent cycling stability (86.62% retention in capacitance over 10 000 cycles). Moreover, the device can achieve a superior energy density of 36.82 μW h cm −2 and a maximum power density of 1372.73 μW cm −2 . These results demonstrated that the composite film was a promising electrode material and may be useful for the development of flexible high-performance and wearable energy storage devices. More importantly, this strategy provided a facile method for the fabrication of other types of composite film electrodes. A simple and low-cost approach toward flexible and free-standing electrodes is developed.