From pv magazine Global.
Scientists at the University of Illinois at Chicago (UIC) have designed a lithium-carbon dioxide battery that is fully rechargeable and which remained stable over 500 cycles – overcoming two major obstacles to the promising technology.
Lithium-CO2 is among several battery technologies known to have the potential for performance and energy density up to seven times higher than today’s lithium-ion batteries, according to UIC, but maintaining stability with repeated cycling has proven problematic.
The UIC group found a way around the problem and announced a lithium-CO2 battery which maintained stability and capacity over 500 cycles. The device is described in the paper A Long‐Cycle‐Life Lithium–CO2 Battery with Carbon Neutrality, published in Advanced Materials.
A common problem with such batteries is an accumulation of carbon on the catalyst as the storage device discharges, a process which ultimately leads to failure. “The accumulation of carbon not only blocks the active sites of the catalyst and prevents carbon dioxide diffusion but also triggers electrolyte decomposition in a charged state,” said Alireza Ahmadiparidari, lead author of the paper.
To get around the problem the group used nanoflakes of molybdenum disulfide as a catalyst at the cathode and a hybrid ionic liquid/dimethyl sulfoxide electrolyte material which they hoped would help incorporate carbon into the cycling process and prevent performance-damaging buildup.
“Our unique combination of materials helps make the first carbon-neutral lithium carbon dioxide battery with much more efficiency and long-lasting cycle life,” said Amin Salehi-Khojin, associate professor of mechanical and industrial engineering at UIC.
While the paper relies on theoretical calculations to describe the battery’s reversible operation, the group appears confident in the importance of its discovery. “This achievement paves the way for the use of CO2 in advanced energy storage systems,” reads the paper’s abstract.