The Korea Electronics Technology Institute (KETI) said on the 15th that it has developed a "nickel-based next-generation porous diffuser" and succeeded in manufacturing it at a size of more than 1,500 square centimeters, meeting one of the conditions for commercialization.
A porous diffuser is one of the components used in water electrolysis for producing green hydrogen. It is known as a key component of water electrolysis, along with catalysts, membranes, and separators. The porous diffuser developed this time is a component for alkaline water electrolysis (AWE) and anion exchange membrane (AEM) water electrolysis, both of which operate in an alkaline environment.
Conventional alkaline water electrolysis and anion exchange membrane water electrolysis mainly used nickel foam, a sponge structure with pores measuring 400 to 500 micrometers (one millionth of a meter). This falls short of the theoretical optimal pore distance for water electrolysis, which is 10 to 20 micrometers. The research team manufactured a porous diffuser with a pore size of 10 to 20 micrometers using a powder sintering method that produces the material by sintering nickel powder. This allows the generated hydrogen and oxygen gases to be discharged smoothly.
In addition, the enhanced capillary action created by the small pores quickly fills the space vacated by bubbles with water, giving it high water electrolysis efficiency. Capillary action is a phenomenon in which liquid rises upward against gravity along a fine gap.
The research team manufactured cells with a zero-gap structure that minimizes the distance between the electrode and the membrane, and tested their performance. As a result, the team said the water electrolysis performance of the newly developed component was about 24% and 59% higher compared to the previously used nickel foam.
Through joint research with LT Metal, Korea's largest porous diffuser manufacturer, the institute also succeeded in developing the porous diffuser at a size of more than 1,500 square centimeters. An area of more than 1,500 square centimeters is considered one of the conditions for commercializing porous diffusers.
"From the early stage of technology development, we conducted research considering not only performance but also commercialization, and we have reached a level where commercialization is possible," said Lim Hyun-soo, head of the institute's Renewable Energy Research Center, who led this research. "We plan to secure cost-reduction technology and product reliability so that products can be commercialized as soon as the market opens."
