Développement Et Caractérisation Des Électrolytes Plus Sûrs Et Versatiles Pour Les Batteries Au Lithium Métallique Ou Post-lithium
Author | : Hoang Phuong Khanh Ngo |
Publisher | : |
Total Pages | : 0 |
Release | : 2019 |
ISBN-10 | : OCLC:1154810934 |
ISBN-13 | : |
Rating | : 4/5 (34 Downloads) |
Book excerpt: Safety issues related to chemical leakage, external heating, or explosion restrain the advancement of renewable storage devices based on classical liquid electrolytes. The urgent need for safer batteries requires new technologies such as the replacement of carbonate solvents by green ionic liquid-based electrolytes or the use of conducting polymer membranes. Moreover, facing a future shortage of raw materials such as lithium, trends are to promote the development of rechargeable batteries based on abundant elements i.e. alkali/alkaline-earth metals. A better understanding of cation conductive behavior in these electrolytes become the mainstream for developing high-security lithium and post-lithium batteries.In this work, the first goal was to focus on the physical and ionic transport properties of several binary systems based on the solution of different alkali/alkaline-earth TFSI salts in a common ionic liquid BMIm TFSI. These ionic liquid electrolytes possess unique characteristics that are promising for electrolyte applications e.g. low vapor pressure, non-inflammable, high thermal stability, with sufficient ionic conductivity. These mixtures are studied with the multi-technique approach to reach thermodynamics (thermal properties), dynamics (viscosity, ionic conductivity self-diffusion coefficients) and structural (IR and Raman spectroscopy) description of these systems. The cationic transport behavior in these ionic liquid electrolytes is strongly influenced by the nature of the cation and its concentration. These viscosity dependent phenomena are related to the alkali/alkaline-earth coordination shell.Another goal of this work is the development of new single-ion conducting polymers based on PEO as solid electrolytes for safer lithium and post-lithium rechargeable batteries. These materials exhibit a cation transference number which nearly reaches unity for the cross-linked ionomers and multi-block copolymers. The cycling tests in symmetric lithium-metal cell affirmed the reversibility of electrolyte with stable lithium plating/stripping between two electrodes. High performances in lithium metal batteries using 'home-made' LiFePO4 cathodes demonstrate the potential of these materials as solid electrolytes. An ultimate aim showed the conductivity behavior of the alkali cations in the different polymer matrix. Thanks to the grafting anionic function distributed along the polymer chain, the effect of cation size on its mobility were clearly observed.