26650 lithium battery is a type of cylindrical lithium battery specifications. Used for power tools, lighting, wind-scenery energy storage, electric vehicles, toys, instruments and meters, UPS backup power, communication equipment, medical equipment and military lights.
The definition of the model is: 26650, that is, the diameter of the battery is 26mm, the length of the battery is 65mm, cylindrical shape of the battery (as shown in the figure). Generally used to call lithium battery, including lithium primary battery and lithium ion battery. Common useful nickel-cobalt manganese cathode materials, lithium iron phosphate materials made of lithium battery - INR26650-3.6V-4500mAh, IFR26650-3.2V-3200mAh.
Safety performance
The overcharge performance
After standard battery charging, measure the initial state of the battery. When the battery state is normal, charge to 10.0V at 3C current, and then switch to constant voltage charging until the current is 0.01C and stop. Observe changes in the appearance of the battery.
Results: no fire, no explosion
Discharge performance
After standard battery charging, measure the initial state of the battery. When the battery state is normal, discharge at 0.5C to 0V. Observe changes in battery appearance.
Results: no fire, no explosion
External short circuit
Battery charging standards, measuring the battery of the initial state, placed in a direct short circuit in the explosion-proof cover is negative (line resistance is not more than 50 m Ω), when the battery temperature down to about 10 ℃ lower than the peak temperature when the experiment is over. Observe the temperature and appearance of the battery.
Results: no fire, no explosion
Thermal abuse
The initial state of the battery was measured. After standard charging, the battery was placed in the oven, and the temperature was increased to 130±2℃ at a rate of (5±2℃) /min and kept warm for 30min. Observe changes in battery appearance.
Results: no fire, no explosion
fall
The initial capacity of the battery was tested. After standard charging, the initial state of the battery was measured. The test battery was dropped vertically and horizontally from the lowest height of 1m to the concrete floor, requiring two drops.
Results: no fire, no explosion
Heavy shock
A steel rod with a diameter of 15.8mm is placed in the middle of the fully charged battery; Then the hammer, weighing 10Kg, was freely dropped from a height of 1.0m to the top of the battery.
Results: no fire, no explosion
Extrusion test
The electric core is placed between the two extrusion surfaces of the extrusion equipment. The cylindrical electric core shaft is parallel to the extrusion surface, and the pressure is gradually increased to 13kN, and the pressure is maintained for 1min.
Results: no fire, no explosion
