Domestic researchers have developed a polymer electrolyte membrane that can considerably improve hydrogen storage technology using electrochemical methods.
A joint research team led by So Soon-young, a senior researcher at the Korea Research Institute of Chemical Technology, and Professor Lee Sang-young of Yonsei University announced on the 20th that they have developed a next-generation separation membrane for hydrogen storage that applies a hydrocarbon-based polymer electrolyte membrane. The separation membrane plays a role in keeping the anode and cathode within the device from contacting each other.
Liquid organic hydrogen carriers (LOHC) are liquid substances that can store hydrogen, with toluene commonly used. When hydrogen attaches to toluene, it forms methylcyclohexane (MCH), which is used to store or release hydrogen through this reaction. However, in cases where toluene is used as an LOHC, there was an issue with toluene permeating through the separation membrane in the electrochemical device, resulting in loss.
The research team newly designed a hydrocarbon-based 'SPAES separation membrane' to minimize toluene permeation while maintaining performance. This is akin to designing channels in a membrane that are very narrow, only one-fiftieth the thickness of a human hair. This structure hampers toluene molecules from spreading into the membrane, slowing the rate at which toluene passes through the membrane by about 20 times compared to before.
As a result, the amount of toluene permeation was reduced by 60%, and the efficiency of the hydrogenation reaction recorded a higher figure of 72.8% compared to the previous membrane's 68.4%. The performance over 48 hours was also excellent. The effect of suppressing electrode contamination was also proven, and there was no chemical instability or structural changes in the separation membrane itself, indicating a high potential for long-term use.
The research team forecasted that if an integrated device capable of directly storing generated electricity is developed along with an independent high-efficiency hydrogen storage system, commercialization could be possible around 2030. Lee Young-guk, director of the Chemical Research Institute, noted that "this technology has great potential for application in various eco-friendly energy systems such as hydrogen fuel cell vehicles and hydrogen power generation, and is expected to contribute to the activation of the hydrogen economy."
The findings of this research were published as a cover paper in the international journal 'Journal of Materials Chemistry A' in February.
References
Journal of Materials Chemistry A (2025), DOI: https://doi.org/10.1039/D4TA06773H