Rapid evaluation method for cycle performance of graphite negative electrode material for lithium battery

Abstract

The invention relates to a rapid evaluation method for the cycle performance of a graphite negative electrode material for a lithium battery. The method is characterized in that rapid evaluation of the cycle performance of the graphite negative electrode material is achieved by using an electrochemical impedance spectroscopy, an all-battery three-electrode test and a capacity increment-based dQ / dV-V curve and combining a local SOC circulation method. The rapid evaluation method has the beneficial effects that the rapid evaluation method has in-situ nondestructive characteristics, and is shortin test period, high in efficiency, low in cost, simple in process, easy to operate and high in reliability; the cycle performance of the battery can be detected without destroying the battery; 40-70%of test time can be shortened; the energy consumption can be greatly reduced and manpower and material resources are greatly saved; the rapid evaluation method can be carried out in a room-temperature environment; complicated conditions are not needed; and compared with a traditional method, the rapid evaluation method has the advantage that the test time is obviously shortened. The rapid evaluation method is applicable to a circular battery, a square battery and a soft package battery, is free of limitation of the size and can be widely applied to massive production; the electric quantity can be significantly saved; the cost can be significantly reduced; and the manpower and material resources are greatly saved.

Description

technical field [0001] The invention belongs to the field of electrochemistry, and in particular relates to a rapid evaluation method for the cycle performance of lithium battery graphite negative electrode materials. Background technique [0002] The current method for evaluating the cycle performance of graphite anode materials for lithium batteries is mainly to make full batteries, and then conduct cycle life tests according to a certain cycle system. Most of them are fully charged and discharged, and the test is terminated until 80% of the initial life. Take the 3C consumer battery with relatively low general life expectancy as an example, which generally requires a cycle life of 500 to 1,000 cycles. Using the 1C full charge and discharge system, it takes about 50 days to 100 days to test the cycle life of 500 to 1,000 cycles. Taking the long-life energy storage battery as an example, the cycle life of 3000 to 6000 times is generally required, and the 1C charging and di...

AI Technical Summary

Problems solved by technology

[0003] In view of this, the traditional method of evaluating the negative electrode cycle performance takes too long, consumes a lot of energy, and costs too much. It needs to occupy the test equipment for a long time, which invisibly increases the cost of the equipment.

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