A team of researchers in Japan and China have created a new technology that could be used to capture and store atmospheric carbon in a solid form. The research was published this week in Joule, an energy journal from Cell Press. Joule scientific editor Rahul Malik said the battery technology represents “an unforeseen but intriguing way to look at carbon fixation.”
The researchers made their discovery by accident. They were developing a version of the elusive lithium-air battery, but through experimentation realized that their design was able to isolate some of the carbon that makes up carbon dioxide molecules found in the atmosphere and store that carbon as a solid dust.
Carbon removal solutions have gained new interest around the world as climate change mitigation becomes a more pressing matter. Some experts now agree that without large scale carbon removal solutions in place, cutting new carbon dioxide emissions won’t be sufficient to keep the Earth below the 2 degree Celsius mark.
But current carbon removal solutions — which range from planting more carbon-eating plants to capturing carbon dioxide in rock formations — aren’t easy to deploy on large scales, nor are they able to remove carbon from the atmosphere fast enough, as these solutions rely on natural processes that would normally take thousands to millions of years.
Developing carbon removal technologies haven’t gained much steam, either, because they face some logistical hurdles — like finding suitable places to store the captured carbon, which is typically in the form of a liquid or gas. Plus, manufacturing those technologies tend to lead to more GHG emissions over the lifecycle of the technology, making these solutions rather moot.
“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,” said Haoshen Zhou, researcher at Japan’s National Institute of Advanced Industrial Science and Technology and China’s Nanjing University, and senior author on the published paper.
The new battery approach is a small but promising step in a new direction for carbon removal. The team had been working to develop a lithium-carbon dioxide battery, but recharging their prototype resulted in a deposition of solid carbon. That doesn’t make for a very good battery, the researchers said, but it did present the team with a new and novel way of potentially capturing carbon in the atmosphere.
The team found that the decomposition of lithium carbonate — the process that generates the solid carbon within the battery — fixes a third of the carbon in carbon dioxide into a solid form, and that process occurs at an energy efficiency rate of about 70%. The caveat is that the technology only works with pure carbon dioxide gas as the input.
The next step, researchers said, is to develop a way for the design to utilize regular atmosphere as the input, which would enable the device to be used in carbon capture and removal solutions for ambient air — sometimes referred to as direct air capture (DAC). Researchers said the technology could also be used to separate and release the oxygen in carbon dioxide molecules as a gas, and for use in removing other polluting gases and compounds like carbon monoxide or sulfur dioxide from the ambient air.