Safety performance testing of
26650 lithium batteries.
1. Overcharge performance
After standard charging of the battery, measure the initial state of the battery. When the battery is in normal condition, charge it to 10.0V with a current of 3C, and then switch to constant voltage charging until the cut-off current is 0.01C before terminating. Observe the appearance changes of the battery.
Result: No fire, no explosion
2. Overdischarge performance
After standard charging of the battery, measure the initial state of the battery. When the battery is in normal condition, discharge it to 0V at 0.5C. Observe the changes in the appearance of the battery.
Result: No fire, no explosion
3. External short circuit
After standard charging of the battery, measure the initial state of the battery and place it in an explosion-proof cover to directly short-circuit its positive and negative poles (with a total resistance of no more than 50m Ω). The test ends when the battery temperature drops to about 10 ℃ below the peak temperature. Observe the temperature and appearance changes of the battery.
Result: No fire, no explosion
4. Hot abuse
Measure the initial state of the battery. After standard charging, place the battery in an oven and raise the temperature to 130 ± 2 ℃ at a rate of (5 ± 2 ℃)/min for 30 minutes. Observe the changes in the appearance of the battery.
Result: No fire, no explosion
5. Falling off
Test the initial capacity of the battery, measure the initial state of the battery after standard charging, and freely drop the test battery from a height (lowest point height) of 1m vertically and horizontally onto a cement floor, requiring two drops.
Result: No fire, no explosion
6. Heavy object impact
Place a steel rod with a diameter of 15.8mm in the middle of a fully charged battery; Then, a 10kg hammer is freely dropped from a height of 1.0m onto the upper part of the battery.
Result: No fire, no explosion
7. Squeezing test
The battery cell is placed between the two extrusion surfaces of the extrusion equipment, with the cylindrical battery cell axis parallel to the extrusion surface. The pressure is gradually increased to 13kN and maintained for 1 minute.
Result: No fire, no explosion
