Scientists have been trying to make lithium-carbon dioxide batteries for years. The technology promises to pack seven times more energy than lithium-ion batteries. And it provides a way to use carbon dioxide captured from power plant and factory exhaust.
But the chemistry has been thorny and the batteries have suffered from low lifetimes. In fact, exactly one year ago, researchers at MIT reported a practical prototype. It could only be charged 10 times.
Now, researchers have created a new version of the lithium-carbon dioxide battery that lasts for 500 charging cycles. The advance “paves the way for the use of CO2 in advanced energy storage systems,” write researchers from the University of Illinois at Chicago in the journal Advanced Materials.
Lithium-carbon dioxide batteries consist of two electrodes—an anode made of lithium and a cathode made of carbon—and an electrolyte that shuttles charged particles between the electrodes as the battery is charged and discharged.
During discharge, a lithium-carbon dioxide battery produces lithium carbonate and carbon, using up carbon dioxide in the process. When the battery is charging, the lithium carbonate gets used up, but the carbon tends to build up on the cathode, causing the battery to fail after just a few tens of recharging cycles.
The UIC team found a way to work around this by using new materials. They added tiny nanoscale flakes of molybdenum disulfide to the catalyst used at the cathode. And they used a new hybrid electrolyte.
Together, this produces a composite of lithium carbonate and carbon instead of producing the two separately, which prevents carbon buildup. As a result, the battery lasts for 500 charging cycles.
“Lithium-carbon dioxide batteries have been attractive for a long time, but in practice, we have been unable to get one that is truly efficient until now,” said Amin Salehi-Khojin, a professor of mechanical and industrial engineering at UIC.
Source: Alireza Ahmadiparidari et al. A Long‐Cycle‐Life Lithium–CO2 Battery with Carbon Neutrality. Advanced Materials, 2019.