(1) Overcharge performance 26650 Li ion battery After standard charging, measure the initial state of the battery. When the battery state is normal, use 3C current to charge to 10.0v, and when the current is 0.01c, turn to constant voltage stop. Observe the appearance change of the battery. Result: No fire or explosion

(2) The over discharge performance of 26,650 lithium-ion battery after standard charging, and the initial state of the battery. When the battery is in normal condition, discharge to 0V at 0.5c. Observe the appearance change of the battery. Result: No fire or explosion

(3) After the 26650 lithium-ion battery is charged as standard, the external circuit is shorted, the initial state of the battery is measured, the battery is put into the explosion-proof cover, and the positive and negative electrodes are directly shorted (the total resistance of the line is not greater than 50m). When the battery temperature drops to about 10 ℃ lower than the peak temperature, the test is completed. Observe the temperature and appearance changes of the battery. Result: No fire or explosion

(4) The initial state of 26650 Li ion battery was measured by thermogravimetry. After standard charging, put the battery in the oven, and the temperature rises to 130± at the rate of (5± 2 ℃) min; Keep the temperature at 2 ℃ for 30 minutes. Observe the appearance change of the battery. Result: No fire or explosion

(5) Drop test the initial capacity of 26650 lithium ion battery. After standard charging, measure the initial state of the battery, and drop the test battery vertically and horizontally from the position with a height of 1m (the height of the lowest point) to the cement floor. It needs to be lowered twice. Result: No fire or explosion

(6) The steel bar with a diameter of 158mm is placed under the impact of the weight of the fully charged battery; Then lower the 10kg hammer from 1.0m to the upper part of the battery. Result: No fire or explosion

(7) The extrusion test core is placed between two extrusion surfaces of the extrusion equipment. The axis of the cylindrical core is parallel to the extrusion surface. Gradually increase the pressure to 13 kn and maintain the pressure for 1 min. Result: No fire, no explosion