Researchers have designed1 a new type of fuel cell based on a composite polymer electrolyte membrane by combining an acid-doped polybenzimidazole membrane with an acid-modified carbon nanotube. This new fuel cell is mechanically stable, prevents acid leaching and shows good proton conductivity.
Existing polymer electrolyte membranes for fuel cells based on polybenzimidazole are unable to perform at high temperature, have low proton conductivity and are susceptible to acid leaching. To overcome these issues, the researchers doped the polybenzimidazole membrane with phosphoric acid and then mixed it with phosphonic-acid-modified multiwalled carbon nanotubes to form a composite membrane.
This composite membrane is expected have a wide range of applications, including for high-temperature sensors, proton pumps and electrolysers, due to its high thermal stability, good proton conductivity and resistance to acid leaching.
"The presence of acid groups on the multiwalled carbon-nanotubes seems to form a network and helps proton conductivity. Furthermore, the presence of the nanotubes provides mechanical stability to the fuel cell," says lead researcher Vijaymohanan K. Pillai.
