UNIST to develop better seawater battery

SOUTH KOREA’S Ulsan National Institute of Science and Technology (UNIST) has secured 5bn won (US$4.4m) in funding to develop better low-cost, eco-friendly seawater batteries.

UNIST has set up a new consortium to develop the batteries, with Korea Electric Power Corporation (KEPCO) and Korea East-West Power Company (EWP). KEPCO and EWP will provide the funding over the next three years. The consortium plans to build a test facility to mass produce seawater batteries, and develop a seawater battery pack, connecting cells to improve charging times.

UNIST is already a world leader in developing seawater batteries, which are very stable and much cheaper than lithium ion batteries. They are thought to be a promising option for large-scale energy storage due to their stability, low cost, and the low fire risk due to the use of seawater. They could also be useful for energy storage for homes and industry and as emergency power supplies for ships or nuclear power plants.

Seawater batteries work on a similar principle to lithium ion batteries, but use the sodium ions in the seawater instead. When the battery is charged, it stores sodium ions in the cathode compartment. During discharge, the sodium is released, reacting with the seawater cathode to form sodium hydroxide, and an electrical current.

Seawater batteries that have been developed so far are hampered by their low power output. UNIST will investigate how to optimise the geometry of the power cells and standardise the battery, testing different sizes and shapes. By 2018, the research team plans to build a battery pack with a capacity of 10 Wh, the average amount of energy required for a family of four for a day, at Ulsan Thermal Power Plant.

“Once this battery is commercialised, we can lead the 47trn won advanced energy storage devices market. It will become one of the major growth engines in the future of our economy, contributing to the revitalisation of the new energy industry,” said Youngsik Kim, professor of energy and chemical engineering at UNIST.