Rapid Detection And Experimental Study Of Self-Discharge Characteristics Of Lithium Ion Batteries

Lithium-ion batteries are widely used in many situations because of their good comprehensive performance.However,due to abnormal self-discharge,the consistency of batteries becomes worse.Overuse of lithium-ion batteries during charging and discharging leads to deterioration of performance and reduction of cycle life.Therefore,self-discharge plays a key role in evaluating the performance of lithium-ion batteries.The storage,transportation and life of lithium-ion batteries are directly related to the self-discharge of batteries.At present,the widely used self-discharge detection method is to evaluate the self-discharge degree of lithium ion battery by comparing the changes of battery parameters before and after the lithium ion has been stationary for a long time in a given test environment.However,this method has many limitations,such as long test cycle and poor test accuracy.Therefore,in view of the above problems,this paper carries out the following research work:1.With the idea of capacity-preserving method and the equivalent circuit model of battery self-discharge,the lithium-ion battery is compensated by small current through the design of hardware circuit of self-discharge detection system,and the voltage at both ends of the battery is maintained unchanged,so that the self-discharge current under arbitrary voltage can be measured quickly and accurately.2.In order to improve the efficiency of testing,the host computer system is introduced to realize automatic testing.The configuration of the test engineer is acquired through the upper computer system,and then the test instruments such as temperature box and battery self-discharge detection device are controlled to change the test conditions.The real-time LOG environment information and self-discharge current information are also obtained,and the data report is finally generated and uploaded to the server.3.Through the experimental study of battery detection under the influence of different environmental temperature,SOC status,storage time and other factors,the feasibility of the fast detection system proposed in this paper is verified.The self-discharge test cycle which needs 28 days to complete is shortened to about 30 hours,and the self-discharge test of battery in different environments can be realized quickly.