High-Performance Supercapacitor of Functionalized Carbon Fiber Paper with High Surface Ionic and Bulk Electronic Conductivity: Effect of Organic Functional Groups. (10th September 2015)

• Record Type: Journal Article
• Authors: Suktha, Phansiri; Chiochan, Poramane; Iamprasertkun, Pawin; Wutthiprom, Juthaporn; Phattharasupakun, Nutthaphon; Suksomboon, Montakan; Kaewsongpol, Tanon; Sirisinudomkit, Pichamon; Pettong, Tanut; Sawangphruk, Montree
• Is Part Of: Electrochimica acta. Volume 176(2015)
• Page Start: 504
• Page End: 513
• Publication Date: 2015-09-10
• Subjects: Supercapacitors -- Pseudocapacitors -- Functionalized carbon fibers -- Surface modification -- a single coin supercapacitor; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2015.07.044
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Highlights: A supercapacitor of organic functionalized carbon fiber paper (f-CFP) exhibits high areal and volumetric capacitances. The performance of the supercapacitor depends on the organic functional group on the surface of the f-CFP. Hydroxyl and carboxylic groups modified on the surface of f-CFP have higher pseudocapacitive property than amide and amine functional groups. The f-CFP exhibits high surface ionic and bulk electrical conductivities. Abstract: Although carbon fiber paper (CFP) or nonwovens are widely used as a non-corrosive and conductive substrate or current collector in batteries and supercapacitors as well as a gas diffusion layer in proton exchange membrane fuel cells, the CFP cannot store charges due to its poor ionic conductivity and its hydrophobic surface. In this work, the chemically functionalized CFP ( f -CFP) consisting of hydroxyl and carboxylic groups on its surface was produced by an oxidation reaction of CFP in a mixed concentrated acid solution of H2 SO4 :HNO3 (3:1 v/v) at 60 °C for 1 h. Other amide and amine groups modified CFP were also synthesized for comparison using a dehydration reaction of carboxylic modified CFP with ethylenediamine and n-butylamine. Interestingly, it was found that hydroxyl and carboxylic groups modified CFP behave as a pseudocapacitor electrode, which can store charges via the surface redox reaction in addition to electrochemical double layer capacitance. The aqueous-based supercapacitor of f -CFP has high areal, volumetric, and specific energy (49.0 μW.h/cm 2, 1960 mW.h/L, and 5.2 W.h/Kg) and power (3.0 mW/cm 2, 120 W/L, and 326.2 W/Kg) based on the total geometrical surface area and volume as well as the total weight of positive and negative electrodes. High charge capacity of the f -CFP stems from high ionic charge and pseudocapacitive behavior due to hydroxyl and carboxylic groups on its surface and high bulk electronic conductivity (2.03 mS/cm) due to 1D carbon fiber paper. The acid treatment process here could be used to improve the charge storage capacity of other carbonaceous materials such as carbon nanotubes.