Biopolymer-based porous carbon as electrode material in battery applications

Abstract

Rechargeable batteries are playing an increasingly important part in today's society and will likely continue to do so in the foreseeable future. Therefore, the increasing demand will need to be met with more sustainable resources as society is otherwise bound to run into the next "end-of-resource"-scenario after fossil fuels. Batteries that are currently state-of-the-art rely on graphitic materials for the anode in order to deliver the desired capacity and performance. However, mining of natural graphite has a huge impact on environment and humans alike while synthetic graphite has a massive CO2 footprint due to the high energy demand arising during its production (14 kg CO2/kg graphite). A replacement of graphite therefore appears highly desirable. This work deals with the optimization of biopolymer-based porous carbon in order to achieve a practical balance between electric conductivity and structural traits. In this particular study, biopolymer-based gels have therefore been prepared by dissolution in acidic conditions before regeneration in a basic bath. Various additives have been added in small amounts to the biopolymer solution before gelation to enhance electric conductivity. After washing and drying the material was carbonized at different temperatures in an inert gas atmosphere to obtain the porous carbon. Finally, the material was milled and characterized regarding surface area, pore size distribution, pore volume, morphology, functionality, elemental composition and electric conductivity in order to evaluate its suitability for battery applications.