Graphitized lignin-based activated carbon fibers and their application in supercapacitors

Abstract

As an abundant bioresource of carbon, lignin has the potential to form carbon fibers (CFs), which can then be used as electrode materials in supercapacitors. However, most studies have only focused on the morphology of CFs, such as the specific surface area and pore-size distribution, while ignoring the influence of the carbon structure in CFs. In this study, Ni(acac)2 was used as a graphitization catalyst in CFs preparation and to further modify the morphology of the fibers. Meanwhile, the addition of Ni(acac)2 remarkably shortened the thermostabilization period from 76 h to 2.25 h, which significantly reduced the energy consumption. The resulting lignin-based activated carbon fibers (LACFs) with graphitized structures presented a controllable pore-size distribution and large surface areas up to 582.7 m2 g− 1. These LACFs were then used as electrode materials in supercapacitors, and the assembled devices displayed high energy and power densities of up to 22.1 Wh kg− 1 and 239 kW kg− 1, respectively, using organic electrolytes.