Method for rapidly evaluating cycle life of lithium ion battery

Abstract

The invention discloses a method for rapidly evaluating the cycle life of a lithium ion battery. According to the method, a battery is placed in a constant-displacement pressure testing tool made of a high-strength material for cyclic testing, and the constant-displacement pressure testing tool comprises a lower end plate, a sliding plate, an insulating bakelite plate, a limiting column, a limiting sliding ring, a sensor fixing plate and a sensor; the attenuation condition of the battery capacity is judged according to the pressure value and the change value of the pressure growth rate in the circulation process; a proportionality coefficient is obtained through comparison with a normal cycle capacity retention rate, expansion force circulation is carried out on batteries of other batches, the service life condition that the batteries of the same batch can finally reach can be judged according to the proportionality coefficient, and the cycle efficiency can be improved by 2-3 times through the method.

Description

technical field [0001] The invention relates to the field of electrical technology, in particular to a method for quickly evaluating the cycle life of a lithium-ion battery. Background technique [0002] With the depletion of traditional energy and the vigorous development of the new energy industry, more and more lithium-ion batteries are used in electric vehicles. However, the cycle test of lithium-ion batteries requires a lot of time and electricity to complete. The cycle life of lithium-ion batteries is at least 1,200 times, and the maximum of ternary material batteries can be more than 2,000 times with 80% remaining capacity. Lithium iron phosphate The material battery can be cycled tens of thousands of times, and it takes a year or more to do a cycle test using the current charging and discharging conditions. Such a long test not only wastes huge manpower, material resources, and financial resources, but also affects the development progress of the battery, and cannot...

AI Technical Summary

Problems solved by technology

However, the cycle test of lithium-ion batteries requires a lot of time and electricity to complete. The cycle life of lithium-ion batteries is at least 1,200 times, and the maximum of ternary material batteries can be more than 2,000 times with 80% remaining capacity. Lithium iron phosphate The material battery can be cycled tens of thousands of times, and it takes a year or more to do a cycle test using the current charging and discharging conditions

Such a long test not only wastes huge manpower, material resources, and financial resources, but also affects the development progress of the battery, and cannot quickly evaluate the differences between batches

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