A team of researchers from Idaho National Laboratory (INL) has developed a new electrode material that simplifies hydrogen generation and energy storage via protonic, ceramic electrochemical cells (PCECs).
The INL team developed a perovskite-based oxygen electrode that not only enables operation at considerably lower temperatures than current technologies require (400–600ºC), but also exhibits “triple-conducting” behavior — it can conduct electrons, oxygen ions and protons within a PCEC.
“We doped nickel into conventional praseodymium cobalt oxide, and we observed that this doping strategy reduces proton migration drastically and greatly improves electrokinetics,” says Dong Ding, INL chemical processing group lead. The triple-conducting characteristic means that the PCEC can be run reversibly without additional hydrogen fuel. “Starting with steam as the feedstock, this a self-sustaining operation to maintain the switching between hydrogen production and power generation,” explains Ding.
The new material is also considerably simpler to synthesize, since it involves fewer elemental components than typical PCEC electrodes, which may require rare materials or more complex doping processes to manufacture. Ding and his team have already fabricated the new cells in industry-standard sizes for adoption into multicell stacks or modular installations. They are also working to test the material’s compatibility with other chemicals to investigate other potential PCEC applications, including the electrochemical activation of natural gas for ethylene and hydrogen co-production.
Conventional electrolysis technologies use electricity to efficiently split water, but are limited by their extremely high operating temperatures — often as high as 800ºC, which make them cost-prohibitive for wide market penetration. Furthermore, at these high temperatures, conductor materials can quickly degrade, explains Dong Ding, INL chemical processing group lead.