Electric cars driven by fuel cell improvements

CSIRO is working on a new type of membrane which it hopes will boost the performance of fuel cells by a factor of four, subsequently transforming the electric vehicle industry. 

The development is a joint effort from CSIRO and Hanyang University in Korea and takes inspiration from, of all things, cactus spikes. The membrane features a water-repellent skin and works much as cactus plant do, thriving in harsh environments by retaining water. 

According to CSIRO researcher and co-author Dr Aaron Thornton, “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.

“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. This membrane works in a similar way. Water is generated by an electrochemical reaction, which is then regulated through nanocracks 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 said.

Professor Young Moo Lee from Hanyang University, who led the research, said this could have major implications for many industries, including the development of electric vehicles. 

According to Lee, one of the main barriers to electric vehicle fuel cell uptake is water and heat management, both of which are addressed through this research. 

The cross-continent team has been working together for over 10 years. For this study, Hanyang University conceived and designed the experiments. Using characterisation and modelling expertise, CSIRO researchers were then able to determine how the membranes behaved under changing humidities.