Method for detecting dispersing uniformity of lithium ion battery slurry

Abstract

The invention discloses a method for detecting dispersing uniformity of lithium ion battery slurry. The method comprises the following steps of: sampling different positions of the slurry; detecting electrical conductivity of the sample; and evaluating the dispersing uniformity of the slurry according to difference of the electrical conductivity of the sample. A novel method for evaluating the dispersing uniformity of the slurry is provided from a special angle. According to the method in the invention, the dispersing uniformity of the slurry is converted from the electrical conductivity to electric conductance with a balanced amount so that the process of evaluating the dispersity of the slurry is exacter and more objective.

Description

technical field [0001] The invention relates to the field of manufacturing lithium ion batteries, in particular to a method for detecting the dispersion uniformity of slurry of lithium ion batteries. Background technique [0002] The characteristics of high safety and long cycle life of lithium iron phosphate battery have made it a hot spot in the development of cathode materials for lithium-ion power batteries in recent years. However, the conductivity of the lithium iron phosphate material itself is very poor, and its conductivity is 6 to 7 orders of magnitude lower than that of traditional materials such as lithium cobalt oxide. In the development of power lithium-ion power batteries, it is required to have excellent rate charge and discharge performance. In response to this, current lithium iron phosphate materials generally improve their own conductivity by surface coating or metal ion doping, reducing the primary particle and secondary agglomeration particle size, or ...

AI Technical Summary

Problems solved by technology

While improving the rate performance of lithium iron phosphate materials, these measures have brought another new problem: the dispersion of lithium iron phosphate slurry

Coating carbon, adding more conductive agents, and material particles with smaller particle sizes all make it difficult to disperse the lithium iron phosphate slurry evenly during the preparation process, and particle agglomeration and conductive agent agglomeration may occur.

The consistency of the pole piece coated with such a slurry is very poor, which causes the internal resistance of the battery to be inconsistent, which in turn affects the performance of the battery.

At present, the traditional method of evaluating the consistency or uniformity of the slurry is to test the viscosity and solid content of the slurry combined with the visual evaluation method. The test results are not very inaccurate and have great shortcomings.

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