Cactus-inspired skin could mean serious improvement for fuel cell electric cars

MAY 2, 2016 BY TERRY DAWES 0 COMMENTS

Scientists with the CommonwealthScientific and Industrial ResearchOrganisation (CSIRO) and HanyangUniversity in Korea have developed amethod of regulating water retentionin polymeric membranes, which couldhave significant impact on making fuelcells smaller and more efficient.

In solving the problem of size thatthermal and water systems add to fuel-cell systems, the scientists drewinspiration from nature, noticing theway a cactus keeps itself regulated forwater and heat in extreme conditions.

“A cactus plant has tiny cracks, called stomatal pores, which open at night when it is cool and humid, and closeduring the day when the conditions are hot and arid. This helps it retain water,” said CSIRO researcher andco-author Dr. Cara Doherty. “This membrane works in a similar way. Water is generated by anelectrochemical reaction, which is then regulated through nano-cracks within the skin. The cracks widenwhen exposed to humidifying conditions, and close up when it is drier.”

According to Dr. Doherty, this new research asserts that a fuel cell can be made up to more than four timesmore efficient in hot and dry conditions, remaining hydrated without the need for external humidifierequipment bulking out its form.

The multi-continent research research project, 10 years in the making and published in the journal Nature,demonstrates how a membrane using what the team calls “nano-cracks”, or tiny fissures in a hydrocarbonpolymer membrane that retards water desorption and maintains ion conductivity, should mean improvedperformance while shrinking fuel cell bulk.

“Fuel cells, like the ones used in electric vehicles, generate energy by mixing together simple gases, likehydrogen and oxygen. However, in order to maintain performance, proton exchange membrane fuel cells – orPEMFCs – need to stay constantly hydrated,” said co-author Dr. Aaron Thornton. “At the moment this isachieved by placing the cells alongside a radiator, water reservoir and a humidifier. The downside is thatwhen used in a vehicle, these occupy a large amount of space and consume significant power.”

The research could have significant impact in Canada, which is a world leader in fuel cells, being home to bothBallard Power Systems (NASDAQ:BLDP) (TSX:BLD) and Hydrogenics Corporation (NASDAQ:HYGS)(TSX:HYG).