Recently, a team of chemists from the University of Waterloo have found the solution for two of major problem surrounding lithium-oxygen battery. Solving the problems, chemists also made a battery which has almost 100 percent coulombic efficiency.
The team for the first in human history has proved that the four electron conversion for lithium-oxygen electrochemistry is highly reversible. According to Linda Nazar who is the Canada Research Chair of Solid State Energy Materials and a senior author on the project said that there are high degree of limitations in thermodynamics, however our work were mainly focused in solving the fundamental issues that people have failed to resolve till this day.
The two major issues involved the peroxide product (Li2O2) which reacts with the porous carbon cathode, resulting in the degradation of cell within and the intermediate of the cell chemistry (LiO2, superoxide).
Nazar and her team tried to switch the porous carbon cathode to a bifunctional oxide catalyst and organic electrolyte into a stable inorganic molten salt. After doing this, they operated the battery at 150 C, and found that Li2O is formed which is more stable in comparison to Li2O2.
They found out that instead of storing O2 as lithium peroxide (Li2O2), it is better to store as Li2O. In doing so, the Lithium-Oxygen battery was able to provide better charging characterized. It also achevied the four electron transfer in the system. This states the energy storage of the battery was increased by whooping 50 percent.