KIER Advances Seawater Electrolysis with Novel Dual-Electrode System

A research team at the Korea Institute of Energy Research (KIER) has developed a groundbreaking seawater electrolysis system that overcomes a long-standing challenge: the buildup of precipitates that hinder performance and interrupt hydrogen production. This innovation offers a promising pathway to efficient and sustainable hydrogen production using seawater, addressing global freshwater scarcity concerns.

The Challenge of Seawater Electrolysis

Water electrolysis, the process of splitting water into hydrogen and oxygen, is a key technology for producing clean hydrogen energy. While freshwater electrolysis is well-established, seawater electrolysis has emerged as a compelling alternative due to the abundance of seawater. However, the presence of magnesium and calcium ions in seawater leads to the formation of precipitates on electrode surfaces, causing performance degradation and requiring frequent, energy-intensive cleaning procedures like acid washing or mechanical removal. This inefficiency has historically limited the widespread adoption of seawater electrolysis.

A Dual-Electrode Solution for Continuous Hydrogen Production

Researchers led by Dr. Ji-Hyung Han from KIER’s Convergence Research Center of Sector Coupling & Integration have introduced a novel system architecture featuring two electrodes. This system operates on a unique principle of “self-cleaning.” One electrode actively produces hydrogen while accumulating precipitates. Simultaneously, the second electrode, already coated with precipitates, temporarily pauses hydrogen production and utilizes naturally acidified seawater – a byproduct of the electrolysis process – to dissolve the accumulated deposits.

The electrodes alternate roles every 48 hours, enabling continuous hydrogen production and precipitate removal without the need for external cleaning interventions. This innovative approach represents the first of its kind globally.

Significant Performance Improvements

Experiments conducted by the KIER team demonstrate substantial performance gains compared to conventional single-electrode seawater electrolysis systems. After 400 hours of operation, the dual-electrode system exhibited only a 1.8% increase in energy consumption, a dramatic improvement over the approximately 27% increase observed in single-electrode systems under the same conditions.

the hydrogen evolution catalyst content decreased by only 20% after 400 hours of operation, showcasing superior stability compared to the 53% reduction seen in the single-electrode system. This enhanced durability translates to lower maintenance costs and a longer operational lifespan.

Future Implications and Collaborative Research

“This study demonstrates that the precipitate issue, a major bottleneck in seawater electrolysis, can be controlled solely through system architecture design,” stated Dr. Ji-Hyung Han. “In particular, by being the first in the world to propose the concept of ‘self-cleaning,’ in which electrodes recover on their own using acidified seawater, this function presents a latest direction for future seawater electrolysis technology development.”

The research was a collaborative effort involving Professor Joohyun Lim’s team at Kangwon National University.

Key Takeaways

• KIER has developed a dual-electrode seawater electrolysis system that overcomes the issue of precipitate buildup.
• The system utilizes a “self-cleaning” mechanism, alternating electrode roles to continuously remove precipitates.
• The new system demonstrates significantly improved performance and stability compared to conventional single-electrode systems.
• This innovation paves the way for more efficient and sustainable hydrogen production from seawater.

Source: Dual electrode system cracks seawater electrolysis deposit problem, TechXplore, March 17, 2026.