TY - JOUR
T1 - Experimental Investigation on the Impact of Various Cooling Conditions for Fast Charging Cylindrical Lithium-ion Cells
AU - Scheller, M.
AU - Aufschläger, A.
AU - Frank, A.
AU - Steinhardt, M.
AU - Sturm, J.
AU - Jossen, A.
N1 - Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2022/12/10
Y1 - 2022/12/10
N2 - Various commercial 18650 and 21700 lithium-ion high-energy cells were investigated experimentally in a wind tunnel for battery cells, regarding their fast-charging performance. Convective cooling with air stream velocities of 1 m s−1, 5 m s−1, and 10 m s−1 were applied at different ambient temperatures ranging from 10 °C to 40 °C. For each combination of convective air stream velocity and ambient temperature, a constant current (CC) charge rate capability test, controlled by voltage and temperature, as well as a multistep constant current (MCC) protocol were investigated. An improved rate capability was achieved with stronger convective cooling when charging was limited to the risk of overheating. For 3C CC charging, the charged capacity was doubled for the 18650, as well as the 21700 format. Overcooling at low temperature deteriorated the rate capability. In general, the rate capability of the 18650 cells was superior to the 21700. Regarding the MCC protocol tests, the charging time, charging efficiency, maximum surface temperature and specific cooling power were evaluated. To minimize MCC charging time, an air stream velocity of 1 m s−1 at 25 °C is recommended to achieve 21 min and 25 min for the 18650 and the 21700 format, respectively. For this, a peak specific thermal cooling power of around 275 W, normalized to a 1 kWh battery pack for better format comparability, was required. The charging energy efficiency was above 91 % for all tests.
AB - Various commercial 18650 and 21700 lithium-ion high-energy cells were investigated experimentally in a wind tunnel for battery cells, regarding their fast-charging performance. Convective cooling with air stream velocities of 1 m s−1, 5 m s−1, and 10 m s−1 were applied at different ambient temperatures ranging from 10 °C to 40 °C. For each combination of convective air stream velocity and ambient temperature, a constant current (CC) charge rate capability test, controlled by voltage and temperature, as well as a multistep constant current (MCC) protocol were investigated. An improved rate capability was achieved with stronger convective cooling when charging was limited to the risk of overheating. For 3C CC charging, the charged capacity was doubled for the 18650, as well as the 21700 format. Overcooling at low temperature deteriorated the rate capability. In general, the rate capability of the 18650 cells was superior to the 21700. Regarding the MCC protocol tests, the charging time, charging efficiency, maximum surface temperature and specific cooling power were evaluated. To minimize MCC charging time, an air stream velocity of 1 m s−1 at 25 °C is recommended to achieve 21 min and 25 min for the 18650 and the 21700 format, respectively. For this, a peak specific thermal cooling power of around 275 W, normalized to a 1 kWh battery pack for better format comparability, was required. The charging energy efficiency was above 91 % for all tests.
KW - 18650
KW - 21700
KW - Convective cooling
KW - Fast charging
KW - Lithium-ion battery
KW - Multi-step constant current
KW - Rate capability
KW - Specific cooling power
KW - Surface temperature
KW - p2D model
UR - http://www.scopus.com/inward/record.url?scp=85141299447&partnerID=8YFLogxK
U2 - 10.1016/j.est.2022.105942
DO - 10.1016/j.est.2022.105942
M3 - Article
AN - SCOPUS:85141299447
SN - 2352-152X
VL - 56
JO - Journal of Energy Storage
JF - Journal of Energy Storage
M1 - 105942
ER -
