The dream of making lithium battery rechargeable due to its high theoretical energy density and their less weight came true. The chemist from the University of Waterloo successfully solved the issues of chemistry and stability. Thus they have created a near 100 percent coulombic efficient working rechargeable battery.
Based on their study, they found four electron conversion of lithium-oxygen electrochemistry is highly reversible. The electron storage of lithium-oxygen batteries doubles due to four electron conversion. This battery is also known as lithium-air batteries.
The first issue is that the intermediate of cell chemistry (superoxide, LiO2) and the peroxide product (Li2O2) reacts with the porous carbon cathode. This process degrades the cell from within. The next issue is the consumption of organic electrolyte by superoxide. This process reduces the life of the battery.
The chemist from Waterloo changed the organic electrolyte to a more stable inorganic molten salt and the porous carbon cathode to a bifunctional metal oxide catalyst. The battery was operated at 150C. More stable superoxide (Li2O) was formed instead of peroxide (Li2O2). Thus highly reversible Li-oxygen battery with coulombic efficiency touching 100 per cent was accomplished.
The battery maintained excellent charging characteristics by storing oxygen as lithium oxide (Li2O) instead of lithium peroxide (Li2O2). The battery attained maximum four-electron transfer in this system and the theoretical energy storage is increased by fifty per cent. “By swapping out the electrolyte and the electrode host and raising the temperature, we show the system performs remarkably well,” informed Nazar, who is also a University member of the Waterloo Institute for Nanotechnology, Research Professor in the Department of Chemistry, and senior author on the project. Chun Xia, a postdoctoral fellow is a lead author on the study and Chun Yuen Kwok is the co-author, a Ph.D. student. Both students work in Nazar’s lab. This excellent discovery needs furthermore work to bring it to the next level. Lithium finds a unique place in battery for its unmatched less weight and lowest reduction potential of any chemical element.