What are the test methods for lithium battery performance?

What are the testing methods for lithium battery performance? Lithium battery performance testing mainly includes voltage, internal resistance, capacity, internal pressure, self-discharge rate, cycle life, sealing performance, safety performance, storage performance, appearance, etc. Regarding the safe use and disposal of lithium batteries, the national standards require general requirements for the safety of civil lithium batteries, and lithium battery testing to ensure safe use. lithium battery. What are the test methods for JPG lithium battery performance? Method 1. Self-discharge test The self-discharge test of nickel-cadmium-nickel metal hydride battery is: because the standard charge retention test time is too long, generally use 24 hours to quickly test the charged self-discharge retention capacity, and charge the battery at 0.2 to 1.0CV. 1C discharge battery for 80 minutes, Pause for 15 minutes, discharge 10V at 1C, measure the discharge capacity C1, and then charge the battery at 1C for 80 minutes, let the test capacity after sitting for 24 hours 1CC2, C2/C1x100% should be less than 15% The self-discharge test of lithium batteries is as follows: generally 24 hours Self-discharge retention ability is fast test charge. At 0.2~3.0V, the C discharge battery is charged with 1C constant current and constant voltage to 4.2V, cut-off current: 10 horses, 15 minutes after shelving, 1C discharge to 3.0V to test its discharge capacity C1, then the battery is charged with 1C constant current and constant voltage to 4.2V, cut-off current 100mA, 1C, and the test capacity after 24 hours of sitting is C2, C2/C1x100% should be greater than 99%. Method two, internal resistance measurement The internal resistance of a lithium battery refers to the internal resistance that occurs when the current flows through the battery when the battery is working. It is generally divided into AC internal resistance and DC internal resistance. Since the internal resistance of the rechargeable battery is very small and the electrodes are easily polarized, the polarization internal resistance will appear when measuring the DC internal resistance, so the true value cannot be measured. Measuring AC internal resistance can prevent the influence of polarization internal resistance and get the true internal resistance value. The AC internal resistance test method is as follows: the lithium battery is equivalent to an active resistor, and the battery is supplied with a constant current of 1000HZ, 50mA, the voltage is sampled, rectified, and filtered, and the resistance value is accurately measured. Method 3. Internal pressure test Lithium battery internal pressure test (UL standard) to test whether the lithium battery leaks or catches fire at a height of 15,240 meters (low pressure 11.6kpa). Specific steps: charge with 1C constant current and constant voltage to 4.2v, cut-off current 10mA, put in a low-pressure box, pressure 11.6kpa, temperature (20±3°C), and store for 6 hours. The battery will not explode, catch fire, rupture or leak. Method 4. Impact experiment When the lithium battery is fully charged, a hard rod with a diameter of 15.8 mm is placed across the battery, and a weight of 20 pounds is lowered from a height of 610 mm. The battery should not explode, catch fire or leak. Method 5. Lithium battery cycle life test The cycle life test is important to test the charging and discharging time of the lithium battery, when the effective capacity of the lithium battery drops to the allowable value. The specific steps are as follows: Under the ambient temperature of (20±5)℃, discharge the lithium battery with 0.2c constant current to the specified termination voltage (usually 3.0v), and then use 0.2c constant current to charge to the termination voltage (usually 4.2v), transfer to constant voltage charging (usually 0.2c charge termination current); lithium battery continues to discharge to the specified discharge termination voltage at ambient temperature (20±5) ℃ and current 0.2c; lithium battery is at (20±5)℃ cycle, the battery should be used for charging and discharging time no more than 1h, or charging and discharging time no more than 1h. Lithium batteries should be discharged and charged in stepwise and stepwise cycles until the discharge capacity is less than 70% of the rated capacity. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous article: What determines the safety of lithium battery cathode materials?