Comprehensive performance evaluation method for conductive slurry of lithium ion battery

Abstract

The invention provides a comprehensive performance evaluation method for a conductive slurry of an lithium ion battery. The method comprises the following steps: a scraper blade fineness gauge is adopted to measure the conductive slurry, and a dispersibility index of the conductive slurry is evaluated; a contact angle tester is adopted to measure the conductive slurry, and spreadability and flow ductility indexes of the conductive slurry are evaluated; a centrifugal machine is adopted to measure the conductive slurry, and a stability index of the conductive slurry is evaluated; a rheometer is adopted to measure the conductive slurry, and elasticity, viscosity and uniformity indexes of the conductive slurry are evaluated; according to evaluation results of the various indexes of the conductive slurry and a corresponding scoring standard thereof, scores of the various indexes of the conductive slurry are obtained; and, according to the scores and preset weights of the various indexes of the conductive slurry, a comprehensive performance score of the conductive slurry is obtained through a weighted summation calculation. The method has the advantages of easy operation, high practicality, high testing result accuracy, high reliability and good reproducibility; and the method can provide an accurate reference for comprehensive performance of the conductive slurry of the lithium ion battery.

Description

technical field [0001] The invention relates to the technical field of lithium-ion battery manufacturing, in particular to a comprehensive performance evaluation method for lithium-ion battery conductive paste. Background technique [0002] Lithium-ion battery is a new green and environmentally friendly chemical power source that appeared in the early 1990s. It has the advantages of high voltage (single battery voltage up to 3.6V), large specific energy (100-130Wh / Kg), stable discharge voltage, good cycle performance, excellent safety performance, and long storage and working life. It is the current chemical power supply industry. One of the latest development directions. In the preparation process of lithium-ion batteries, the quality of the slurry occupies a crucial position, which will directly affect the process and quality of the subsequent lithium-ion battery production, so the slurry with excellent performance is the foundation of the preparation of lithium-ion bat...

AI Technical Summary

Problems solved by technology

Chinese patent application CN104880384A proposes to use a rheometer to test the shear rate-viscosity curves of the upper and lower slurries after the positive slurry is left in an acid burette to evaluate the stability of the slurry. The two curves overlap well, indicating that the slurry Good stability; on the contrary, the slurry has poor stability

Although this method can objectively reflect the stability of the slurry, it has limitations. It can only test the positive electrode slurry, and the single stability cannot reflect the quality of the slurry.

Chinese patent application CN101382489A proposes a method of measuring the absorbance change rate of the slurry before and after centrifugation to judge the stability of the slurry. Although this method is convenient, it has its disadvantages. First of all, there is no unified standard on the centrifugal speed and time, because different Different slurry properties (such as viscosity) require different rotational speeds and time; secondly, temperature rises and rotational speed changes during the centrifugation process will have varying degrees of impact on the stability of the slurry, which is the key to judging the stability of the slurry. Difficulty resulting in less accurate and repeatable testing

Therefore, the performance of the slurry cannot be evaluated from a single test, and it is necessary to comprehensively evaluate the performance of the slurry from multiple angles

Images