The facts & the project
The increasing development of electric vehicles and of nomadic devices such as laptops, digital tablets and smartphones forces to get more and more efficient autonomous sources of energy. Lithium batteries, that appeared at the beginning of the 90’s, were a real revolution at the time because of their energy density and their lifetime but, while being widely used today, their technology is limited in terms of capacity, delivered power and safety.
All that to underline the necessity to improve existing materials or to conceive new ones for extending battery life or even to develop other types of battery such as sodium or manganese batteries. It is the subject of the work carried out by Mouna Ben Yahia and the Chimie théorique, méthodologies et modélisation team, at the Institut Charles Gerhardt in Montpellier: “We intend to understand the limitations of current materials by analysing their electronic structure in link with the study of their thermodynamic and vibrational properties”, Mouna Ben Yahia said.
The results
This approach helped the researchers to identify the origin of the low capacity and the instability of some materials in order to improve them and/or to explore new ones. As an example, for the first time, they recently discovered the origin of the Raman modes obtained in-situ during the electrochemical process and linked them to the structural and electronic properties of LiMixMn1-X02 (Lithium-Nickel-Manganese-Oxygen or LNMO) that presents a an interesting electrochemical potential.
Realised within the French network on electrochemical energy storage and in collaboration with a team from the Institut Paul-Scherrer in Switzerland, the result of these time consuming studies will be published, in 2016, in an article under preparation.