TY - JOUR
T1 - Analyzing the Aging Behavior of Lithium-Ion Cells Connected in Parallel Considering Varying Charging Profiles and Initial Cell-to-Cell Variations
AU - Schindler, Markus
AU - Jocher, Philipp
AU - Durdel, Axel
AU - Jossen, Andreas
N1 - Publisher Copyright:
© 2021 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.
PY - 2021/9
Y1 - 2021/9
N2 - Aging behavior and long-term cell-to-cell variations have been much more frequently investigated in single-cells than cells connected in parallel. In particular, the literature lacks a study investigating the aging behavior of cells in parallel that is based on defined cell-to-cell variations and on the results of a previous single-cell aging study. Moreover, present studies are unable to exclude the impacts of measurement systems on their final results. To counter this deficiency, a novel 4-wire measurement technique is used which does not influence the current distribution but allows both single and parallel measurements to be recorded without changing the measurement configuration. Cells in parallel generally displayed improved aging behaviors in comparison to those seen in the single-cell aging study and the positive influence of extended CV-charging was evident, as long as the CV-charging phase was limited in length. It was also observed that the exclusion of critical voltage ranges exerted the most significant influence on the aging rate and dominates the influence of initial cell-to-cell variations in the long-term. As a result, it is recommended that module manufacturers reduce the effort spent on initial cell matching strategies for cells in parallel in favor of developing cell-specific charging profiles.
AB - Aging behavior and long-term cell-to-cell variations have been much more frequently investigated in single-cells than cells connected in parallel. In particular, the literature lacks a study investigating the aging behavior of cells in parallel that is based on defined cell-to-cell variations and on the results of a previous single-cell aging study. Moreover, present studies are unable to exclude the impacts of measurement systems on their final results. To counter this deficiency, a novel 4-wire measurement technique is used which does not influence the current distribution but allows both single and parallel measurements to be recorded without changing the measurement configuration. Cells in parallel generally displayed improved aging behaviors in comparison to those seen in the single-cell aging study and the positive influence of extended CV-charging was evident, as long as the CV-charging phase was limited in length. It was also observed that the exclusion of critical voltage ranges exerted the most significant influence on the aging rate and dominates the influence of initial cell-to-cell variations in the long-term. As a result, it is recommended that module manufacturers reduce the effort spent on initial cell matching strategies for cells in parallel in favor of developing cell-specific charging profiles.
UR - http://www.scopus.com/inward/record.url?scp=85116378215&partnerID=8YFLogxK
U2 - 10.1149/1945-7111/ac2089
DO - 10.1149/1945-7111/ac2089
M3 - Article
AN - SCOPUS:85116378215
SN - 0013-4651
VL - 168
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
IS - 9
M1 - 090524
ER -