Membrane inspired by Cactus gives electric cars a spike
A new membrane inspired by the desert plant, cactus is developed by scientists from Commonwealth Scientific and Industrial Research Organization (CSIRO) and Hanyang University in Korea. The membrane which is described in the journal Nature, has the ability to boost the performance of fuel cells.
The research showed that in hot conditions, the membrane, which features a water repellent skin, could improve the efficiency of fuel cells by a factor of four. Young Moo Lee from Hanyang University, who led the research, predicted that this could have major implications for many industries, including the development of electric vehicles.
“Fuel cells, like the ones used in electric vehicles, generate energy by mixing together simple gases, like hydrogen and oxygen. However, in order to maintain performance, proton exchange membrane fuel cells or PEMFCs need to stay constantly hydrated,” Dr. Thornton said. “At the moment this is achieved by placing the cells alongside a radiator, water reservoir and a humidifier. The downside is that when used in a vehicle, these occupy a large amount of space and consume significant power,” he said.
According to CSIRO researcher and co-author Dr. Cara Doherty, the team’s new cactus-inspired solution offers an alternative. “A cactus plant has tiny cracks, called stomatal pores, which open at night when it is cool and humid, and close during the day when the conditions are hot and arid. This helps it retain water.” Dr. Doherty said.
“This membrane works in a similar way. Water is generated by an electrochemical reaction, which is then regulated through nano-cracks within the skin. The cracks widen when exposed to humidifying conditions, and close up when it is drier. This means that fuel cells can remain hydrated without the need for bulky external humidifier equipment. We also found that the skin made the fuel cells up to four times as efficient in hot and dry conditions,” she added.
The cross-continent team has been working together for over ten years. For this study, Hanyang University conceived and designed the experiments. Using characterization and modelling expertise, CSIRO researchers were then able to determine how the membranes behaved under changing humidities.
