Oak Ridge National Laboratory, a research institute under the US Department of Energy, has developed a battery consisting of two electrodes in a saltwater solution which pulls atmospheric carbon dioxide into its electrochemical reaction and releases only valuable byproducts.
The laboratory said it tested two battery formulations that convert carbon dioxide gas into a solid form that has the potential to be used in other products. Designed for grid energy storage, they do not have to function as a portable, closed system. The batteries could convert carbon dioxide from stationary, industrial sources.
One of these new battery types maintained its capacity for 600 hours’ use and could store up to 10 hours’ electricity. Researchers also identified, studied and overcame the primary challenge, a deactivation caused by chemical build-up that had been an obstacle for the other battery formulation.
Of the new battery formulations, one combines carbon dioxide with sodium from salt water using an inexpensive iron-nickel catalyst. The second combines the gas with aluminum. For example, carbon dioxide generated by a power plant could be pumped through a tube into the liquid electrolyte, creating bubbles similar to those in a carbonated soft drink, it said. During battery operation, the gas bubbles turn into a solid powder.
Ilias Belharouak, an ORNL corporate fellow and initiative director, said the laboratory’s investment in innovative ideas and approaches can transform the way we think about storing energy beyond lithium-ion batteries and other conventional electrochemical energy storage systems. “What a fantastic scenario: Using free electrons to store CO2 and converting it to revenue-generating products is a concept I never would have imagined 10 years back, but this is just a start,” he said.
Image: The battery developed at Oak Ridge, consisting of two electrodes in a saltwater solution, pulls atmospheric carbon dioxide into its electrochemical reaction and releases only valuable byproducts. Andy Sproles/ORNL
