4
INR 21700 50 E
Cylindrical Lithium Ion Cell
7.2 DISCHARGE METHOD
7.2.1
Cells shall be discharged at a constant current of 0.2C to 2.5 volts
7.2.2
Cells shall be discharged at a constant current of 0.5C to 2.5 volts
7.2.3
Cells shall be discharged at a constant current of 1.0C to 2.5 volts
7.2.4
Cells shall be discharged at a constant current of 2.0C to 2.5 volts
7.2.5
Cells shall be discharged at a constant current of 1.0C to 2.5 volts
7.3 INTERNAL IMPEDANCE
7.4 DISCHARGE RATE CHARACTERISTICS
The impedance shall be measured by 6.1.2
Initial Internal Impedance ≤ 20mΩ
Cells shall be charged per stardard charge method at
25°C ±2°C and discharged per 7.2.1 (0.2C), 7.2.2 (0.5C),
7.2.3 (1C), 7.2.4 (2C). The discharge capacity of each cell
at respective discharge rate shall be compared with the
discharge capacity at 0.2C and the percentage shall be
calculated. Each cell shall meet or exceed the requirements
of Table 1.
Table 1
0.2C
100%
0.5C
≥95%
1.0C
≥93%
2.0C
≥90%
7.5 CYCLE LIFE
Charge cells per 7.1.2. Rest 30 minutes. Discharge per 7.2.3. Rest 30 minutes before recharge. The test enviromental
temperature is 25°C ±2°C. A cycle is defined as one charge and one discharge. Discharge capacity shall be measured
after
8
00 cycles.
Discharge capacity (
8
00th Cycle) ≥
8
0% of 1st Cycle Capacity
7.6 STORAGE CHARACTERISTICS
7.6.1
After charge as per stardard charge method 7.1.1, store the testing cells at 25°C ± 2°C for 28 days. Then discharge as
per 7.2.3. Then the same cell is fully charged as per 7.1.1 again and discharged a second time and measured as per 7.2.3
The recovery discharge capacity (2nd discharge capacity) ≥90% of Initial capacity.
7.6.2
After charge as per stardard charge method 7.1.1, store the testing cells at 55°C ± 2°C for 7 days. Then discharge as
per 7.2.3. Then the same cell is fully charged as per 7.1.1 again and discharged a second time and measured as per 7.2.3
The recovery discharge capacity (2nd discharge capacity) ≥90% of Initial capacity.
TerraE Confidential Proprietary and not be reproduced without written permission from BMZ Germany GmbH, Zeche Gustav 1, 63791 Karlstein
