Durable carbon cloth electrode enables 800-hour stable hydrogen output in seawater

Durable carbon cloth electrode enables 800-hour stable hydrogen output in seawater

 

A team created an acid-treated carbon cloth electrode that withstands industrial currents for more than a month in seawater electrolysis.

 

Hydrogen is becoming a cornerstone in the push for cleaner energy. From steelmaking to power generation, industries are exploring hydrogen as a way to cut carbon emissions.

 

Water electrolysis, splitting water into hydrogen and oxygen using electricity, offers a sustainable production method, especially when powered by renewable energy.

 

But most systems still rely on freshwater, a resource under mounting stress due to climate change, population growth, and competing demands from agriculture and industry.

 

Seawater electrolysis could help bypass this limitation, but the technology faces serious hurdles, from corrosion caused by chloride ions to performance loss under industrial-scale operating conditions.

 

Now, researchers in South Korea say they have taken a significant step toward solving those problems.

 

Dr. Ji-Hyung Han’s team at the Korea Institute of Energy Research (KIER) has developed a carbon cloth-based electrode that runs stably for more than 800 hours under high current while directly using seawater.

 

Tackling corrosion and performance loss

In seawater electrolysis, the electrode support plays a decisive role in efficiency and lifespan. Metal-based supports corrode quickly in the presence of chloride ions. Carbon cloth has emerged as an alternative because of its conductivity, corrosion resistance, flexibility, and cost benefits.

 

Yet, existing carbon cloth electrodes have struggled to withstand high current operation above 500 mA/cm² for more than 100 hours, a basic threshold for industrial use.

 

Han’s team overcame these limitations with an optimized acid treatment process. They immersed the cloth in concentrated nitric acid at 100°C for one hour.

 

To prevent acid concentration from fluctuating due to evaporation, they designed a sealed treatment vessel, ensuring stable conditions.

 

The treated carbon cloth became highly hydrophilic, allowing cobalt, molybdenum, and ruthenium ions to spread evenly.

 

Even with only 1% ruthenium by weight, the electrode reduced overpotential by about 25% compared to conventional cobalt-molybdenum catalysts.

 

This translated into a roughly 1.3 times more efficient hydrogen evolution reaction at the same current density.

 

The electrode maintained its initial performance after more than 800 hours of continuous operation at 500 mA/cm².

 

Tests revealed no leaching of ruthenium or cobalt into the electrolyte, underscoring the material’s corrosion resistance and structural stability.

 

The team also produced a 25 cm² version of the electrode, suggesting scalability for industrial modules.

 

Han, said:

This technology marks the world’s first successful case of long-term operation over one month under industrial-level high current conditions in seawater electrolysis using a carbon cloth-based electrode,

 

She, added:

We plan to further advance the technology to the demonstration level through extended durability testing beyond 1,000 hours and research on scaling up to large-area cell modules and stacks.

 

Commercialization potential ahead

The ability to reduce overpotential means lower energy costs for hydrogen production.

 

Combined with proven long-term stability in real seawater conditions, the development could accelerate industrial adoption of seawater electrolysis.

 

The project was funded by the National Research Council of Science & Technology under South Korea’s Ministry of Science and ICT.

 

Source:   Hydrogencentral