Measurement of Li-Ion Battery Electrolyte Stability by Electrochemical Calorimetry
L. J. Krause, L. D. Jensen and V. L. Chevrier (2017).
Journal of The Electrochemical Society. 164(4) A889. https://doi.org/10.1149/2.1651704jes
Abstract
Recent work describing the use of high precision coulometry combined with isothermal heat flow calorimetry has shown promise in studying electrolyte reactivity in Li-ion batteries. In this paper we describe what we term an “integration/subtraction” technique for determining the electrolyte reactivity as a function of cell voltage in Li-ion full pouch cells. We apply this method to the characterization of a base electrolyte blend of ethylene carbonate and ethyl methyl carbonate (EC/EMC 3/7 w/w) with 1 M LiPF6. We then show how the parasitic thermal power and coulombic efficiency are affected by the addition of the reactive carbonates vinylene carbonate and 1-fluoro-ethylene carbonate to the base electrolyte. We show how this method can discriminate the effectiveness of additives used in Li-ion cells as a function of cell voltage and cycle life.
