What are the battery performance test methods? What should I pay attention to? Let us know about it.
Charge and discharge mode of button battery
Including constant current charging, constant voltage charging, constant current discharge, constant resistance discharge, hybrid charge and discharge, and step type and other different modes of charge and discharge. In the laboratory, constant current charging (CC), constant current-constant voltage charging (CC-CV), constant voltage charging (CV), constant current discharge (DC) are often used to test and analyze the battery charging and discharging behavior, while step charging The discharge mode is mostly used for testing DC internal resistance, polarization and diffusion impedance performance. Considering the content of active materials and the influence of the pole piece size on the test current, constant current charging often occurs in the form of current density, such as mA/g (current per unit mass of mass), mA/cm2 (current per unit pole area) . The charge and discharge current is usually expressed by the charge and discharge rate, that is, the charge and discharge rate (C) = charge and discharge current (mA) / rated capacity (mA · h), such as a battery with a rated capacity of 1000 mA·h at 500 mA When the current is charged and discharged, the charge and discharge rate is 0.5 C. At present, the industry standard QCT/743-2006, which has been published for lithium-ion batteries for electric vehicles, indicates that the charge and discharge current of lithium ion is C/3, so the charge/discharge behavior test with C/3 is also often found in laboratory lithium ion. Battery charge and discharge test.
Rate performance test
There are three forms, including constant current constant voltage charging with the same rate, and constant current discharge test at different rates to characterize and evaluate the performance of lithium ion batteries at different discharge rates; or use the same rate for constant current discharge, and Different rate constant current charging test to characterize the charging performance of the battery at different magnifications; and charging and discharging using the same rate for charge and discharge testing. Commonly used charge and discharge rates are 0.02 C, 0.05 C, 0.1 C, C/3, 0.5 C, 1 C, 2 C, 3 C, 5 C and 10 C.
When testing the cycle performance of the battery, it is mainly necessary to determine the charge and discharge mode of the battery, periodically cycling until the battery capacity drops to a certain value (usually 80% of the rated capacity), the number of charge and discharge cycles experienced by the battery, or The test battery cycle performance was characterized by comparing the remaining battery capacity after the same cycle of the cycle. In addition, the battery test environment has a certain impact on its charge and discharge performance.