Clean and plentiful, hydrogen is a promising fuel source, but there are a few problems standing in the way of it becoming mainstream. South Korean scientists have now developed a new system for producing hydrogen from water, which that they say overcomes some of these issues and produces the gas more efficiently than other water electrolysis systems.

The new device was developed by a research team consisting of scientists from the Ulsan National Institute of Science and Technology (UNIST), Korea Institute of Energy Research (KIER) and Sookmyung Women's University, and is based on an existing design called a solid oxide electrolyzer cell (SOEC).

These work like other electrolyzers in that an electrical current splits water into its constituent molecules – hydrogen and oxygen – which can then be harvested. The difference is that in this setup, both electrodes are solid-state, as is the electrolyte that carries the ions between them.

This has a few advantages over systems that use liquid electrolytes – namely, the liquids need to be topped up occasionally, and over time they tend to corrode other components. And since solid-state electrolyzers operate at higher temperatures, they don't need as much electrical energy to function because they can draw energy from that heat.

But SOECs still have room for improvement. There are two main designs that use different electrolytes: One allows only oxygen ions to pass through, and the other only hydrogen ions. In either case, that one-way street limits the amount of hydrogen that can be produced.