Binder free carbon nanofiber electrodes derived from polyacrylonitrile-lignin blends for high performance supercapacitors

Abstract

Lignin was blended with polyacrylonitrile (PAN) in different ratios and fabricated into carbon nanofiber electrodes by electrospinning followed by thermal stabilization, carbonization and subsequent activation by CO2 of the carbonized mats. These carbon fiber electrodes exhibit high surface area, high mesoporosity, high graphitic content and high electrical conductivity. Activated carbon nanofiber mats derived from PAN:Lignin 70:30 blends display a surface area of 2370 m2 g−1 with 0.635 cm3 g−1 mesopore volume. These results are due to the selective partial removal of carbonized lignin during the activation step. Coin cell supercapacitors employing these electrodes exhibit 128 Fg−1 specific capacitance, 59 Wh kg−1 energy density and a 15 kW kg−1 power density when operated at 3.5 V using an ionic liquid electrolyte. Since lignin is an inexpensive, abundant, and green polymer, incorporating it into carbon blends enhances the scalability of such materials in energy storage applications.

Processing, Carbonization, and Characterization of Lignin Based Electrospun Carbon Fibers: A Review

“…Various types of carbon materials such as graphene, carbon nanotubes and activated carbon have been reported to manufacture electrodes for supercapacitors. Lignin-carbon fiber has been studied in different publication to manufacture electrodes for capacitors/supercapacitors (Fang et al, 2017b;Lei et al, 2017;Ma et al, 2018;Yu et al, 2018;Perera Jayawickramage et al, 2019;Roman et al, 2019;Schlee et al, 2019a,b;Yun et al, 2019). Lai et al (2014b) applied lignin-carbon fibers as electrodes to prepare electrochemical supercapacitors as summarized in Table 4.…”

A review on graphene based transition metal oxide composites and its application towards supercapacitor electrodes

“…To date, numerous materials such as new carbon fabrics [143], conductive polymers, hybrid metals oxides have been deployed as super-capacitors electrodes [144][145][146]. Carbon was generally used in its various forms as supercapacitors of electrode components, due to High specific capacity and elevated production density [147,148].…”

Carbon fibers derived from pure alkali lignin fibers through electrospinning with carbonization

“…The tensile strengths of commercial PAN-based carbon fiber are in the range of 3 GPa to 7 GPa, while the tensile strength of typical lignin-based CF was only 0.48 GPa (Lin et al 2013). Despite the lower strength properties, lignin-based CFs have substantial potentials for the next generation of alternative electronic and electrode applications (Ma et al 2016;Jayawickramage et al 2019). Therefore, in this work, electrical property was the only focus.…”