Effects of different charging and discharging modes on thermal behavior of lithium ion batteries

Abstract

SummaryThe heat release law of lithium ion battery during different cycles of charging‐discharging rate was studied by the LAND testing device. Studies have shown that: When charging at 0.5C and discharge cycles at 0.5C, 1C, 2C, and 3C, respectively, the battery cycle heat dissipation increases with the increase of the discharge rate, and the temperature rise ratio of the battery after the 3C cycle is 0.5C, 1C, 2C is higher by 30.8 °C, 21.4 °C, and 9 °C; 0.5C, 1C, 2C, 3C rechargeable battery temperature rise after 1C discharge and 0.5C, 1C, 2C, 3C charge cycles, respectively. The heights are 13.8 °C, 18.1 °C, 37.6 °C, and 44.3 °C, respectively; when the battery is cycled at a 3C charging‐discharging rate, the battery voltage suddenly changes to 0 V after the 2nd cycle; when the charge current and discharge current are relatively small, the heat generated during low‐rate charging high‐rate discharge cycles is larger, and when the charge current and the discharge current are relatively large, the heat generated at the low‐rate charging high rate discharge cycle is smaller than the high‐rate charging low‐rate discharge cycle. The research obtained the heat dissipation data of lithium‐ion batteries under different charging‐discharging rates, which provided an important basis for the safe operation of lithium‐ion batteries.

Analysis of the pulse frequency affections on the polarization voltage of the Li-ion battery for pulse charging

“…According to equation (10), the pulse period has a great influence on the polarization voltage. Suppose τ1<τ2.…”

“…Secondly, the voltages drop on the internal resistance and polarization resistances dramatically increases with higher charging current, therefore, constant voltage (CV) charging is triggered too early, this prolongs the overall charging time. Research show that reducing the polarization voltage can effectively reduce the charging time [6][7][8][9][10][11][12][13][14][15] . Compared with CV charging, constant current (CC) charging has higher charging speed, hence, a method with compensated the voltage drop is proposed to prolong CC mode to reduce the charging time [6] .…”

Identifying Efficient Cooling Approach of Cylindrical Lithium‐Ion Batteries

“…During discharging, the heat dissipation rate from the surface increases with the increasing rate of the discharge for the same ambient condition. [34] If the cell is charged and discharged for several times (say thousand times), usable battery capacity and life cycle will be reduced due to the formation of large radial temperature gradient in case of radial cooling. In radial cooling, the layers near the surface (outside) are cooled batter than those inside.…”

Effects of Fast Charging Modes on Thermal Performance of Lithium‐Ion Battery

“…In the cycles at 1 C discharging rate and different charging rates (0.5, 1, 2 and 3 C), the heat generation increased with the charging rate. [ 5 ] Dong et al established a model combining the electrochemical–thermal‐coupled model and thermal abuse model to investigate the thermal behavior of the lithium‐ion battery at high charge–discharge rates (>8 C). The results showed that the extremely large output/input current would cause the cutoff voltage to be reached earlier, thus terminating the charge/discharge operation.…”