%0 Journal Article
%A Hildebrand, S
%A Rheinfeld, A.
%A Friesen, A
%A Haetge, J
%A Schappacher, F. M
%A Jossen, A
%A Winter, Martin
%T Thermal analysis of LiNi0.4Co0.2Mn0.4O2/mesocarbon microbeads cells and electrodes: State-of-charge and state-of-health influences on reaction kinetics
%J Journal of the Electrochemical Society
%V 165
%@ 0013-4651
%C Pennington, NJ
%I Electrochemical Soc.
%M FZJ-2018-04871
%P A104-A117
%D 2018
%X The thermal stability of lithium ion batteries was studied by means of Accelerating Rate Calorimetry in Heat-Wait-Search operation on both electrode and cell level. Fresh and aged samples were investigated depending on the state-of-charge (SoC) of a 5 Ah pouch cell comprising mesocarbon microbeads and LiNi0.4Co0.2Mn0.4O2 as the anode and cathode materials. 1 M LiPF6 in EC:DEC 3:7 (by weight) containing 2 wt% VC and 0.5 wt% LiBOB was chosen as the electrolyte. Measurements on the electrode level revealed a higher self-heating rate (SHR) of the cathode compared to the anode for all SoC and state-of-health (SoH) combinations in the temperature range where a self-sustaining decomposition reaction could be detected. A lower SoC showed a lower SHR of the electrode/electrolyte mixture with no reaction detected on the anode side ≤ 50% cell SoC. Cyclic aging led to a decrease in thermal stability of the cathode at lower SoC values with no significant influence on the anode implying a larger safety threat on the cell level. Avrami-Erofeev and autocatalytic reaction models were used to quantify the influences of SoC and SoH on reaction kinetics. Full cell measurements confirmed the observations at a higher SHR.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000431786800014
%R 10.1149/2.0361802jes
%U https://juser.fz-juelich.de/record/851171