Thursday, 23 June 2016
Riverside Center (Hyatt Regency)
B. Flamme (PSL Research University, IRCP, UMR CNRS 8247), M. Haddad, P. Phansavath, V. Vidal (Chimie-Paristech, IRCP, UMR 8247), and A. Chagnes (Chimie-Paristech, IRCP, UMR 8247, RS2E)
The development of new technologies for electrochemical energy storage is one of the main challenges of the next decades. Many hopes now rely on lithium-ion batteries (LiBs) that have invaded the market of laptops and which appear to be the best choice with the short time for electric vehicles, and perhaps for network applications (electricity storage from wind turbines or solar cells for example). Many works concern the search for cathodes with high-energy density but only few studies focus their research on the synthesis of new dipolar aprotic organic solvents for LiBs electrolytes. Thus, there is a need to deviate from traditional approaches for identifying new electrolytes stable to high voltage that are based on "Trial and Errors" approaches. To alleviate this issue, a collaborative project funded by the French Research Agency (ANR) and reuniting multidisciplinary research groups that combines highly and specific complementary skills in organic chemistry, electrochemistry, solution chemistry, thermodynamics and theoretical chemistry was launched in October 2014. The present paper aims at presenting recent advances from this group on the design of new electrolytes for high-voltage batteries.First, a critical review of the physicochemical and electrochemical properties of the electrolytes will be presented in this talk (boiling and melting points, viscosity, ionic conductivity in the presence of lithium salts, oxidation potential, etc.). This critical review highlights the lack of homogeneity in the literature data for performing rational design of electrolytes by means of quantitative structure-property relationship calculations (QSPR). Therefore, these data were completed and homogenized by performing new experiments. In particular, a set of 20 new dipolar aprotic organic solvents were synthesized and characterized.
Second, the physicochemical properties of these new dipolar aprotic organic solvents including viscosity, ionic conductivity and their electrochemical behaviors on graphite, LiCoO2, NMC and Lithium rich electrodes as well as platinum and glassy carbon electrodes will be presented and discussed. In particular, their anodic stability will be discussed based on DFT calculations giving interesting information at the molecular level.
Finally, this talk will give the main drawbacks and the next challenges in the design of new electrolytes for 5V lithium-ion batteries.
