Safety function test of
26650 lithium battery.
1. Overcharge function
After charging the battery according to the standard, measure the initial condition of the battery. When the battery condition is normal, charge it to 10.0V with a current of 3C, and then switch to constant voltage charging until the current reaches 0.01C before stopping. Observe the appearance changes of the battery.
Result: No fire, no explosion
2. Overpass function
After charging the battery according to the standard, measure the initial condition of the battery. When the battery condition is normal, discharge it to 0V at 0.5C. Observe changes in the appearance of the battery.
Result: No fire, no explosion
3. External short circuit
After charging the battery according to the standard, measure the initial condition of the battery and place it in an explosion-proof cover to directly short-circuit its positive and negative poles (the total resistance of the circuit is not greater than 50m Ω). The test is completed 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 condition of the battery, charge it according to specifications, place it in an oven, and raise the temperature to 130 ± 2 ℃ at a rate of (5 ± 2 ℃)/min for 30 minutes. Observe changes in the appearance of the battery.
Result: No fire, no explosion
5. Falling
Test the initial capacity of the battery, standardize charging, measure the initial condition of the battery, and freely drop the test battery from a height (lowest point height) of 1m in a straight and horizontal direction to 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. Kneading test
Place the battery cell between the two kneading surfaces of the kneading device, with the cylindrical battery cell axis parallel to the kneading surface. Gradually increase the pressure to 13kN and maintain the pressure for 1 minute.
Result: No fire, no explosion
