What kind of electrical performance characteristics do lithium batteries have?

　　1. The internal resistance characteristics of lithium batteries

　　The ohmic resistance curve of a lithium iron phosphate battery presents the following characteristics: in the wider SOC range in Figure 1, that is, in the interval of SOC=[10%, 100%], the ohmic resistance of the battery changes very little, while In the lower SOC range, the ohmic resistance increases significantly with the decrease of SOC.

　　It should be noted that the internal resistance of the battery changes very complicatedly and is affected by factors such as temperature, depth of discharge, charge and discharge rate, and cycle times.

　　2. Lithium battery open circuit voltage characteristics

　　The OCV-SOC relationship curve of lithium-ion batteries is less affected by temperature, discharge rate, and aging factors, but there are certain differences in the characteristic curves of charging and discharging.

　　3. The capacity characteristics of lithium batteries

　　As can be seen from Figure as below, the curve of the lithium battery during the discharge process can be divided into 3 stages:

　　1) The terminal voltage of a lithium battery drops rapidly in the initial stage, and the greater the discharge rate, the faster the voltage drops.

　　2) The battery voltage enters a stage of slow change. This period is called the battery platform area. The smaller the discharge rate, the longer the platform area lasts. The higher the platform voltage, the slower the voltage drops.

　　3) When the capacity of the battery is nearly discharged, the output voltage of the lithium battery begins to drop sharply until it reaches the discharge cut-off voltage.

　　Lithium-ion battery (LIB) has become the main energy storage solution in modern social life. Among them, lithium iron phosphate batteries are a perfect substitute for lead-acid batteries and are the first choice in the energy storage industry.