Climate Insider Brief:
- Researchers at Oak Ridge National Laboratory (ORNL) are developing batteries that both store renewable energy from sources like solar and wind and capture carbon dioxide (CO2) from industrial emissions, converting it into useful products.
- two types of CO2-converting batteries have been created. One uses sodium and an iron-nickel catalyst, while the other uses aluminium.
- These batteries have shown potential for long-term storage and effective CO2 capture, addressing previous challenges like electrode degradation.
Researchers at the Department of Energy’s Oak Ridge National Laboratory (ORNL) are pioneering battery technologies that aim to mitigate climate change through two main approaches: expanding the use of renewable energy and capturing airborne carbon dioxide (CO2). These innovative batteries store energy generated by solar panels or wind turbines and, through an electrochemical reaction, capture CO2 from industrial emissions and convert it into useful products.
ORNL researchers have developed and tested two distinct battery formulations capable of converting CO2 gas into a solid form, which can potentially be utilised in various applications. One type of these batteries demonstrated the ability to maintain its capacity for 600 hours and store up to 10 hours of electricity. The primary challenge, a deactivation caused by chemical buildup, was successfully addressed for the second battery formulation.
Ilias Belharouak, an ORNL Corporate Fellow and initiative director, highlighted the significance of the Transformation Energy Science and Technology (TEST) initiative at ORNL. He expressed excitement about ORNL’s commitment to innovative energy storage solutions beyond traditional lithium-ion batteries, emphasising the dual benefits of storing energy and converting CO2 into revenue-generating products.
How the Batteries Work
Batteries function through electrochemical reactions, moving ions between two electrodes via an electrolyte. Unlike portable batteries, those designed for grid energy storage do not need to be a closed system, allowing ORNL researchers to develop and test batteries that convert CO2 from stationary industrial sources. For instance, CO2 emissions from a power plant could be channelled into the battery’s liquid electrolyte, where it transforms into a solid powder during operation.
The new ORNL battery formulations include one that combines CO2 with sodium from saltwater using an iron-nickel catalyst, and another that combines CO2 with aluminium. Both approaches use abundant materials and a liquid electrolyte, making the batteries safer and more stable than existing technologies.
Innovations and Overcoming Challenges
Previous CO2 battery research often relied on reversible metal-CO2 reactions, which still released CO2 and caused electrode degradation. The ORNL-developed CO2 batteries, however, do not emit CO2. Instead, the carbonate byproduct dissolves in the liquid electrolyte, either enhancing battery performance or being filtered out without interrupting operation. This design can also be adjusted to produce byproducts useful in industries like pharmaceuticals and cement.
The sodium-carbon dioxide (Na-CO2) battery, developed first, encountered issues with a film forming on the electrode surface, causing deactivation. By using specialised microscopes and X-ray techniques, researchers identified how the film formed and how to prevent it. They discovered that operational changes in the charge/discharge cycle could prevent the film buildup, thus reactivating the battery.
Long-Term Storage with Aluminum-CO2 Battery
The aluminium-carbon dioxide (Al-CO2) battery was the focus for long-term storage solutions. After experimenting with various electrolyte solutions and synthesis processes, researchers developed a battery capable of storing more than 10 hours of electricity, operating for over 600 hours without losing capacity. This battery also captures almost twice as much CO2 as the Na-CO2 battery and can operate in a single chamber, enhancing ion movement.
The challenge for the Al-CO2 battery is scaling up, while for the Na-CO2 battery, developing a stable ceramic membrane to separate the battery chambers is key.
Future Prospects and Contributions
Other ORNL scientists involved in this project include Marm Dixit, Mengya Li, Sabine Neumayer, Yaocai Bai, Anuj Bisht, Yang Guang, and former ORNL researcher Rachid Essehli. The research received funding through ORNL’s Laboratory Directed Research and Development program and utilised the Center for Nanophase Materials Sciences, a DOE user facility at ORNL.
Managed by UT-Battelle for the Department of Energy’s Office of Science, ORNL continues to address critical challenges through basic research in the physical sciences. For more information, visit energy.gov/science.
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SOURCE: EurekAlert!
Featured Image: Credit: Andy Sproles/ORNL, U.S. Dept. of Energy
