Design of K Value Detection System for Self-discharge of Lithium-ion Battery
Lithium-ion battery self-discharge detection plays an important role in evaluating the capacity,cycle characteristics and service life of a single lithium-ion battery or battery pack.Rapid detection of the spontaneous consumption of stored power of lithium-ion batteries in open circuit conditions is currently a research hotspot in this field.The open-circuit voltage method was used to measure the voltage drop of lithium-ion batteries per unit time,namely the self-discharge K value,to characterize the degree of self-discharge.Additionally,a self-discharge K value detection system for lithium-ion batteries was designed.The system was composed of upper and lower computer computers,connected by Type-C mode,which allowed for the detection of the self-discharge rate of lithium-ion batter-ies.A ternary lithium-ion battery was used as the test object,and a 14-day standing experiment was conducted to detect the self-dis-charge K value during the standing process.The test results show that the system not only shortens the self-discharge detection time of lithium-ion batteries,but also accurately detects the self-discharge rate of lithium-ion batteries.The self-discharge K value of the lithi-um-ion batteries was detected under five states of charge:20%,40%,60%,80%,and 100%,and at four temperature conditions:20 ℃,50 ℃,-20 ℃,and-40 ℃.According to the K-value test results,the influence of state of charge and self-discharge ambient temperature on the self-discharge rate of lithium-ion batteries can be analyzed.
lithium-ion batteryself-dischargeopen circuit voltage methodself-discharge K valueSTM32 system