Exploring the development of natural biopolymer (chitosan)-based proton exchange membranes for fuel cells: A review

Abstract

Fuel cells use proton exchange membranes (PEMs) to transform chemical energy into electricity. PEMs are selective barriers that permeates protons, obstructing gases and other species like electrons. A polymer electrolyte containing both positively and negatively charged ions forms a PEM. Nafion, a perfluorinated sulfonic acid membrane, is the most popular polymer membrane used as PEM. It exhibits good chemical stability, strong mechanical qualities, and high proton conductivity. However, it has several issues, one of which is its propensity to degrade with time, especially at high temperatures and in the presence of pollutants. The other draw backs associated with perfluorinated based membranes are that they are expensive and non-eco-friendly In order to address these issues, researchers are looking into new materials and methods to form a PEM so that the performance and durability are enhanced .Chitosan (biopolymer) based PEMs have demonstrated great potential to be used in fuel cells. They are environmentally friendly and economical. However, the key challenge in using chitosan in fuel cells is their relatively poor ionic conductivity. Researchers have developed various strategies to improve their conductivity, such as doping with conductive materials or incorporating functional groups that enhance charge transfer. Overall, chitosan has shown promise as renewable and sustainable material for use in fuel cells. The review summarizes the current development and evolution of chitosan-based PEMs.