Method for detecting and sorting self-discharge performance of lithium iron phosphate battery

Abstract

The invention relates to a method for detecting and sorting self-discharge performance of a lithium iron phosphate battery. The method comprises the following steps of: charging to less than 70 percent of a SOC ( State Of Charge); 2, storing for a period of time, wherein the period of time is called as a stabilization time; 3, testing an open-circuit voltage of the battery, wherein the tested voltage in the step is called as V1; 4, storing for one period of time, wherein the period of time is called as a self-discharge time; 5, testing an open-circuit voltage of the battery, wherein the tested voltage in the step is called as V2; 6, calculating a voltage drop amount of the battery, the voltage drop amount is called as a delta V, wherein the delta V is equal to the V1 minus the V2; and 7, determining that a battery of which the delta V is greater than a standard value is an unqualified product, and determining that a battery of which the delta V is smaller than the standard value is a good product. According to the method provided by the invention, the self-discharge performance of the lithium iron phosphate battery can be sorted in a short time without needing a high temperature aging, the problem of high detection cost caused by shortening the detection time by using the traditional method needing using the high temperature aging to accelerate the electricity discharge speed is solved.

Description

technical field [0001] The invention relates to a method for detecting and sorting the self-discharge characteristics of lithium batteries, in particular to a method for detecting and sorting the self-discharge characteristics of lithium iron phosphate batteries. Background technique [0002] Taking into account the limited oil resources and environmental pollution problems, power batteries have been developed unprecedentedly. The lithium iron phosphate battery has been continuously developed as a power battery because of its high power, long life and safety. At present, the consistency of the lithium iron phosphate battery is an important factor restricting the development of the entire power battery. Due to the inevitable introduction of metal impurities and dust in the raw materials and battery production process, these metal impurities and dust will directly affect the self-discharge consistency of the finished battery, thereby affecting the cycle life of the power modul...

AI Technical Summary

Problems solved by technology

[0004] The invention provides a self-discharge sorting method for lithium iron phosphate batteries that can sort out the self-discharge performance of lithium iron phosphate batteries in a short period of time without high-temperature aging, and solves the need for high-temperature aging acceleration in existing sorting methods The problem of high detection cost caused by the method of discharging speed to shorten the detection time

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