Scientists studying the work of lithium-air batteries have found a unique way to capture and store carbon dioxide away from the atmosphere. Using a design for a lithium-carbon dioxide battery, the researchers developed a way to separate solid carbon dust from gaseous carbon dioxide, and it is possible to use the same method to separate oxygen.
Flow chart of stored energy and fixed carbon using li-co2 technology
Researchers in Japan and China have developed a way to separate solid carbon powder from gaseous carbon dioxide, using a design used in lithium-ion carbon dioxide batteries, and it is possible to separate oxygen in the same way.
Since carbon dioxide has a great impact on the greenhouse effect and global warming, converting carbon dioxide emissions into other carbonaceous compounds is the most ideal way to deal with it. Examples range from natural processes, such as converting carbon dioxide into oxygen and sugar, to man-made processes, such as injecting carbon dioxide into rock formations to be captured as carbonate minerals.
"The problem with most of the physical and chemical pathways used for co2 fixation is that their products are gases and liquids that require further liquefaction or compression, which will inevitably result in additional energy consumption and more co2 emissions." "Instead, we are working on carbon dioxide fixation electrochemical strategies to produce solid carbon products, and even lithium carbon dioxide batteries that can provide the energy needed for the process," said senior author Haoshen Zhou from Japan's national institute of advanced industrial technology and nanjing university in China.
The researchers tried to charge the prototype lithium-carbon battery with a carbon-fixation strategy. Unlike fully regenerated lithium ions and carbon dioxide during a battery discharge, lithium carbonate, like a reversible li-co2 battery, breaks down to produce extra carbon, allowing unseparated oxygen to react quickly with the battery electrolyte. Usually, this accumulation leads to physical degradation of the battery and shortens its functional life, but the deposition of solid carbon has its unique advantages, indicating that carbon fixation will become a stable and easy to handle method.
Rahul Malik, science editor of joule, said: "the most extraordinary aspect of this work is the conversion of a third of the carbon dioxide species into carbon, which is theoretically more than 70 per cent efficient. "The battery structure looks at carbon fixation in an unpredictable but interesting way. The researchers were unable to meet both of these goals in a single device, because the method achieved both carbon fixation and reduced battery performance. However, by incorporating a small amount of ruthenium into their designs as a catalyst, they can avoid large carbon deposits and are more reversible, turning their carbon fixers into functional li-co2 batteries.
Another challenge for carbon sequestration and battery performance is the transfer of pure co2 to the air environment, a jump that could deal with co2 in the atmosphere and lead to a theoretically powerful but still unstable lithium-air battery technology. Zhou said the fixation technology may also be suitable for washing other harmful or polluting gases from the atmosphere, such as carbon monoxide, sulfur dioxide, nitric oxide and nitrogen dioxide.
Looking ahead, the researchers are also confident in the potential of their system to eventually achieve a way to convert carbon dioxide into pure carbon and oxygen. "The release of charged oxygen, coupled with the accumulation of solid carbon, could lead to electrochemical carbon dioxide fixation strategies similar to those used for photochemical cooperation," they conclude.