Method for evaluating cycle performance of ternary material

Abstract

The invention belongs to the technical field of lithium-ion batteries. The invention particularly relates to a method for evaluating the cycle performance of a ternary material. A ternary material tobe tested is used as a positive electrode to be prepared into a button cell to be used as a test carrier, and by means of XRD analysis, electrochemical test and other means, the data of delta I003 / I104 and capacity retention ratio of the ternary material to be tested after a few specified times of charge-discharge cycles under the limit test condition are obtained. By substituting data obtained bytesting the button cell into an equivalent mathematical relationship corresponding to a cycle index when delta I003 / I104 values of a known ternary material are the same under the limit test conditionand a conventional test condition; therefore, the charge-discharge cycle life of the ternary material to be detected in the total battery can be rapidly evaluated, and the evaluation efficiency of the material is improved. According to the invention, the performance of the material is evaluated from the perspective of the influence of the crystal structure change of the ternary material on the charge-discharge cycle stability in the charge-discharge cycle process, and the reliability is relatively high.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, in particular to a method for evaluating the cycle performance of ternary materials. Background technique [0002] Due to its high working voltage, energy density, long life and environmental friendliness, lithium-ion batteries have become the power source of a new generation of electric vehicles, electric tools and electronic products, and have been widely used in energy, transportation, communications, etc. in different fields. [0003] Ternary materials, especially high-nickel ternary materials, are the current research hotspots, and have been widely used due to their high capacity and excellent cycle performance. Ternary materials, as a key component of lithium-ion battery cathode materials, determine the basic physical and electrochemical properties of the battery. At present, there are many kinds of ternary electrode materials that have been commercialized in the market. How to quickl...

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Problems solved by technology

This method of material evaluation has a long time period, high input costs, and low evaluation efficiency

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