Cellulose-acetate coating of carbon cloth diffusion layer for liquid-fed fuel cell applications

Direct glucose fuel cells (DGFCs) and direct methanol fuel cells (DMFCs) commonly supply the reducing agent in liquid (aq.) form. In this work, we present key characteristics of implementing cellulose acetate (CA) coatings, which can subsequently be deacetylated toward cellulose, on carbon cloth used as a fuel diffusion layer in aqueous fuel-fed cells. Specifically, we illustrate functionality with an abiotic glucose fuel cell. Carbon cloth with and without a CA coating (with varying deacetylation) was characterized in terms of liquid permeation rate, electronic conductivity, and roll-off angle wetting characteristics. Additionally, fuel cell power production was measured over a variety of fuel concentrations and alkalinities by generating polarization curve data. These coatings facilitated a significant increase in aqueous solution permeation and adhesion properties, as well as providing up to two-fold increases in maximum power generation in an alkaline DGFC, despite experiencing some decreased conductivity of the carbon cloth diffusion layer.