Carbon dioxide (CO2) is a main component of smokestack emissions and the most important greenhouse gas implicated in climate change. This week in ACS Central Science, researchers show that they can turn this pollutant into something useful--a material in high demand for high- tech batteries that are needed to store "green" energy such as solar power, while limiting the environmental impact of current power plants.
From banana peels to peat moss, all sorts of materials have been studied as potential Earth-abundant battery components. Capturing and transforming CO2 into other products is a goal for researchers around the world but previous efforts have focused on making bulk chemicals like methanol, not high-value materials like those needed for lithium and sodium batteries.
Stuart Licht, Cary Pint and coworkers developed a method in which they bubble gas through molten lithium carbonate and electrify the gas to generate products including various forms of carbon, like carbon nanotubes (CNTs) and carbon nanofibers. The researchers showed that the CNTs could be used as anodes, the negative electrode in a battery. Two different forms of CNTs showed stable performance and near 100 percent columbic efficiency. The work proposes a modified flue system for combustion plants that incorporates this process could be somewhat self-sustaining. That's because the side product of the process is pure oxygen, which plants could then use for further combustion. The calculated total cost per metric tonne of CNTs would be much less expensive than current synthetic methods.
A process called STEP turns carbon dioxide from smokestacks into multi-walled carbon nanotubes that can be used in various types of batteries. Credit: Credit: American Chemical Society
source: American Chemical Society