TY  - JOUR
AU  - Dagger, Tim
AU  - Kasnatscheew, Johannes
AU  - Vortmann-Westhoven, Britta
AU  - Schwieters, Timo
AU  - Nowak, Sascha
AU  - Winter, Martin
AU  - Schappacher, Falko M.
TI  - Performance tuning of lithium ion battery cells with area-oversized graphite based negative electrodes
JO  - Journal of power sources
VL  - 396
SN  - 0378-7753
CY  - New York, NY [u.a.]
PB  - Elsevier
M1  - FZJ-2018-04910
SP  - 519 - 526
PY  - 2018
AB  - The accuracy for positional alignment of the positive electrode vs. the negative electrode is of great importance for the quality of assembly of lithium ion cells. Area-oversized negative electrodes increase the tolerance for electrode alignment. In this study, the impact of area-oversizing of the negative electrode on the specific capacity losses during charge/discharge cycling is systematically investigated by using electrochemical and analytical methodologies. It is shown, that with a higher degree of area-oversizing more active lithium is kinetically trapped in the outer negative electrode areas (“overhang”), causing performance-deteriorating losses in usable specific capacity. Nevertheless, most of this “lost” specific capacity is of reversible nature as the trapped active lithium can be electrochemically recovered, which is analytically proven by inductively coupled plasma-optical emission spectrometry (ICP-OES) and laser ablation-inductive coupled plasma-mass spectrometry (LA-ICP-MS). Given this relation, a periodic application of a short constant voltage step after discharge results in a significant performance increase. In contrast, holding the cell in the charged state is detrimental for cells with area oversized negative electrodes as the amount of reversible and irreversible trapped active lithium increases. Based on the obtained insights, the influence of variations of the electrochemical conditions on charge/discharge cycling performance is discussed.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000440876700061
DO  - DOI:10.1016/j.jpowsour.2018.06.043
UR  - https://juser.fz-juelich.de/record/851210
ER  -