Chapter 4 - Cathode electrodes in MFCs

Abstract

Cathodes play a powerful role in determining the power density and cost of microbial fuel cells (MFCs). Thus, controlling the cathode design is an important, fundamental goal of electrochemical science. To date, various cathode designs such as air-cathode, aqueous air-cathode, and biocathode have been used for water treatment and electricity generation in MFCs. Cathode performance is associated with the kinetics of oxidation-reduction reaction (ORR), affecting the electrochemical performance, polarization, and/or power density. In particular, catalyst loading has emerged as a potent way to promote cathode performance. To date, cathode catalysts, including electrocatalysts, photo-electrocatalysts, and biocatalysts, have been developed that target ORR activity. In this chapter, we summarize these recent developments made for the optimization of bioenergy generation. Furthermore, the chapter evaluates cathode concepts and highlights the unique characteristics of these structures in MFC arenas that demonstrate cathode efficiency. In addition, this chapter aims to identify cathodic structures and potential catholytes and produces a road map for future research of MFCs.