High proton conductivity membrane with coconut shell activated carbon

An ideal proton exchange membrane (PEM) used in fuel cells must facilitate fast proton transport, insulate electron conduction, and exhibit adequate thermal and mechanical stability among others. One of the main issues with PEMs is the degradation of proton conductivity as a consequence of membrane dehydration. In this study, an effective bio-friendly solution is sought through the utilization of coconut-shell-based activated carbon (AC) that can act as a "molecular sponge". Our experimental results demonstrate almost an order of magnitude improvement in proton conductivity with only 0.7 % AC particles and a significant enhancement in water sorption of more than 80 % without any compromise in mechanical properties. The mechanism of proton conductivity enhancement in Nafion/AC composite membrane is elucidated, and a new model of proton conductivity as a function of filler content is proposed exhibiting three distinct phases of activated carbon influence.