N-activated carbon fiber produced by oxidation process design and its application as supercapacitor electrode

There are three basic steps to activated carbon fibers (ACF) manufacturing, from PAN fiber: oxidation/stabilization, carbonization and activation. Carbon material, specially ACF is a very attractive material to be used as supercapacitor electrode. The literature describes carbon material surface chemistry importance for supercapacitors application, mainly nitrogen groups by N-doping. Oxidation/stabilization is an important non-explored factor that influence the surface chemical functionality. This work describes the influence of oxidation/stabilization process on ACF production, from textile PAN fiber, and the non-doping nitrogen surface chemistry characteristic caused by the oxidation process design. Its textural, structural and surface was evaluated for supercapacitor electrode. The results show that the oxidation degree can be used as a mechanism of textural and surface chemistry control. The surface chemistry is the key of this work, different oxidation conditions can produce nitrogen compounds that help to increase specific capacitance. The tests showed an increase in capacitance higher than 100% in comparison to the standard oxidation.