While pursing work on the highly desirable but technically challenging lithium-air battery, researchers unexpectedly discovered a new way to capture and store carbon dioxide. Upon creating a design for a lithium-CO2 battery, the research team found a way to isolate solid carbon dust from gaseous carbon dioxide, all while being able to separate oxygen.
As global industry, technology, and transportation grows, the consumption of fossil fuels has increased. According to the U.S. Environmental Protection Agency, the burning of petroleum-based products has resulted in 6,587 million of metric tons of carbon dioxide released into the environment in 2015. The emission of greenhouse gasses like carbon dioxide trap heat in the atmosphere, which researches have linked the global warming. Because of this, capturing and converting carbon emissions has become a highly researched area.
“The problem with most physical and chemical pathways for CO2 fixation is that their products are gases and liquids that need to be further liquefied or compressed, and that inevitably leads to additional energy consumption and even more CO2 emissions,” says Haoshen Zhou, senior author of the recently published research. “Instead, we are demonstrating an electrochemical strategy for CO2 fixation that yields solid carbon products, as well as a lithium-CO2 battery that can provide the energy necessary for that process.”
This from Science Daily:
The researchers encountered the carbon fixation strategy when they tried to recharge a lithium-CO2 battery prototype. Instead of fully regenerating lithium ions and CO2 from the lithium carbonate and carbon produced during battery discharge, as would have taken place with a reversible Li-CO2 battery, the lithium carbonate decomposed, yielding additional carbon, as well as oxygen gas that was not isolated due to rapid reaction with the battery electrolyte. Typically, this kind of buildup causes physical degradation and reduced functional lifespan for a battery, but instead, the deposition of solid carbon boasts a separate advantage, pointing to a promising approach to fix carbon in a stable and easy-to-dispose-of form.
While challenges remain in this development, researchers are excited for the work’s potential in converting CO2 into pure carbon and oxygen gas.