Experimental Investigation of the Influence of the Electrolyte Composition on the Ageing Behavior of Separators in Lithium-Ion Cells

Wednesday, 27 May 2015: 08:00
Salon A-3 (Hilton Chicago)
Y. Kraemer (Deutsche ACCUmotive GmbH & Co. KG), A. Hintennach (Daimler AG), and M. Meiler (Deutsche ACCUmotive GmbH & Co. KG)
The most widely used liquid non-aqueous electrolytes for lithium-ion cells used in  HEV (hybrid electric vehicle), PHEV (plug-in-hybrid electric vehicle) and EV (electric vehicle) applications consist of LiPF6 dissolved in carbonates (e.g. EC, DMC and DEC). These electrolytes undergo a variety of hydrolysis and thermal aging mechanisms [1]. Ongoing decomposition reactions lead to further impurities inside the lithium-ion cell which are not well-known. The separator is a second critical component in lithium-ion cells, which can be classified into three groups according to structure and composition: microporous polymer membranes, non-woven fabric mats and inorganic composite membranes [2].

In this contribution, the decomposition reaction mechanisms are evaluated under a number of different thermal conditions for various commercial electrolytes from automotive lithium-ion cells. Furthermore, their influences on the ageing behaviour of different separator types are investigated. Details of the experimental procedure, analytical methods (NMR, GC-MS, SEM/EDX) and first results will be presented. Finally, we will give an overview of our mechanistic interpretation.


 [1]        P. Handel, G. Fauler, K. Kapper, M. Schmuck, C. Stangl, R. Fischer, F. Uhlig, S. Koller, J. of Power Sources 2014,

             doi: 10.1016/j.jpowersour.2014.05.080

 [2]        S. Zhang, J. of Power Sources 2007, 164, 351 – 364


This research is funded by the German Federal Ministry of Education and Research (BMBF) under the grant number 03X4631E within the cluster “excellence and technological implementation of Battery research (ExcellentBattery).