AFM phase images and 3D height topography of PTI-N-20 and PTI-N-100. Credit: Yiman Gu et al.
Researchers have created a polyanion exchange membrane that provides excellent mechanical and conductive properties for alkaline anion membrane fuel cells. The novel membrane provides improved performance while removing toxic ether bonds used in traditional membranes.
Anion exchange membrane fuel cells (or AEMFCs) are common materials in fuel cell development as they operate in alkaline environments, provide faster redox reaction rates, and are compatible with non-precious metal catalysts. Despite these benefits, OH mobility is around half of H+ in similar conditions and the stability is poor.
“Anion exchange membrane is an important component in fuel cells, and the performance of the membrane profoundly affects the performance and development of fuel cells. How to make a breakthrough in the performance of anion exchange membrane and how to achieve high power density are the issues that our research team has been exploring,” said Zhe Wang, a professor at the Changchun University of Technology.
Conventional anion exchange membranes contain ether bonds. These bonds are not only toxic but are also highly susceptible to degradation during OH- transport. In the study, published in Industrial Chemistry and Materials, the membrane created by the researchers utilizes a polymer backbone that does not contain these ether bonds. By utilizing quaternary ammonium cation and piperidine cation in the anion exchange membrane the membrane contained a tighter ion transport channel which reduced the necessary activation energy needed to transport OH-.
Along with these benefits, the researchers also report improved mechanical properties such as high tensile strength in the membrane. The researchers believe that their work will pave the way for further anion exchange membrane development. “Our next step will be to focus on targeting battery power density improvement to achieve the ultimate goal of industrialized application of anion-exchange membranes,” said Wang.