Low and High Voltage Li-Ion Batteries Using Dinitrile Based Electrolytes

Monday, 14 October 2019
Grand Ballroom (The Hilton Atlanta)
F. Ghamouss (PCM2E E.A. 6299), D. Farhat (Université François Rabelais - Tours), and D. Lemordant (PCM2E (EA6299) - Université François Rabelais de Tours)
Due to their low vapor pressure as well as their electrochemical (5~6 V) and thermal stability, dinitriles N≡C-(CH2)n-C≡N are proposed as alternative electrolyte solvents to alkyl carbonates commonly used in Li- ion batteries. The objective of this communication is to study the physico-chemical behavior of these alternative electrolytes (viscosity, ionic conductivity, thermal behavior, volumetric properties, etc.) and their use in Li-ion batteries. Two battery systems are studied using a lamellar oxide (LiNi1/3Mn1/3Co1/3O2) as positive electrode associated with graphite or Li4Ti5O12 as negative electrodes. The cyclability of electrodes in half-cell and full-cell is studied according to the electrolyte composition and the nature of the dinitrile used. Characterization techniques like: electrochemical impedance spectroscopy, electron microscopy and X-Ray photoelectrons spectroscopy, are used to study the passivation of the negative electrode and the stability of the positive electrode. Furthermore, the effect of adding specific solid electrolyte interphase (SEI) builders is investigated and their efficiency is demonstrated.