TY - JOUR
T1 - Calendar aging of lithium-ion batteries i. impact of the graphite anode on capacity fade
AU - Keil, Peter
AU - Schuster, Simon F.
AU - Wilhelm, Jörn
AU - Travi, Julian
AU - Hauser, Andreas
AU - Karl, Ralph C.
AU - Jossen, Andreas
N1 - Publisher Copyright:
© The Author(s) 2016. Published by ECS.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - In this study, the calendar aging of lithium-ion batteries is investigated at different temperatures for 16 states of charge (SoCs) from 0 to 100%. Three types of 18650 lithium-ion cells, containing different cathode materials, have been examined. Our study demonstrates that calendar aging does not increase steadily with the SoC. Instead, plateau regions, covering SoC intervals of more than 20%-30% of the cell capacity, are observed wherein the capacity fade is similar. Differential voltage analyses confirm that the capacity fade is mainly caused by a shift in the electrode balancing. Furthermore, our study reveals the high impact of the graphite electrode on calendar aging. Lower anode potentials, which aggravate electrolyte reduction and thus promote solid electrolyte interphase growth, have been identified as the main driver of capacity fade during storage. In the high SoC regime where the graphite anode is lithiated more than 50%, the low anode potential accelerates the loss of cyclable lithium, which in turn distorts the electrode balancing. Aging mechanisms induced by high cell potential, such as electrolyte oxidation or transition-metal dissolution, seem to play only a minor role. To maximize battery life, high storage SoCs corresponding to low anode potential should be avoided.
AB - In this study, the calendar aging of lithium-ion batteries is investigated at different temperatures for 16 states of charge (SoCs) from 0 to 100%. Three types of 18650 lithium-ion cells, containing different cathode materials, have been examined. Our study demonstrates that calendar aging does not increase steadily with the SoC. Instead, plateau regions, covering SoC intervals of more than 20%-30% of the cell capacity, are observed wherein the capacity fade is similar. Differential voltage analyses confirm that the capacity fade is mainly caused by a shift in the electrode balancing. Furthermore, our study reveals the high impact of the graphite electrode on calendar aging. Lower anode potentials, which aggravate electrolyte reduction and thus promote solid electrolyte interphase growth, have been identified as the main driver of capacity fade during storage. In the high SoC regime where the graphite anode is lithiated more than 50%, the low anode potential accelerates the loss of cyclable lithium, which in turn distorts the electrode balancing. Aging mechanisms induced by high cell potential, such as electrolyte oxidation or transition-metal dissolution, seem to play only a minor role. To maximize battery life, high storage SoCs corresponding to low anode potential should be avoided.
UR - http://www.scopus.com/inward/record.url?scp=84982671382&partnerID=8YFLogxK
U2 - 10.1149/2.0411609jes
DO - 10.1149/2.0411609jes
M3 - Article
AN - SCOPUS:84982671382
SN - 0013-4651
VL - 163
SP - A1872-A1880
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
IS - 9
ER -