Method for testing mixing uniformity of lithium battery anode material

Abstract

The invention relates to a method for testing mixing uniformity of a lithium battery anode material. The method comprises the steps: conductive carbon and graphite and mixed to obtain a mixed material, the actually measured mass proportion of the conductive carbon at any n positions in the obtained mixed material is tested and calculated, and if difference values between the actually measured massproportion of the conductive carbon at any n positions and the theoretical mass proportion of the conductive carbon added into the raw materials are all within + / -0.1%, it shows that the anode material is mixed evenly. The method provides the guiding direction for improving of a mixing technology, and the efficiency of the preparation process of the anode material is improved advantageously.

Description

technical field [0001] The invention relates to the field of preparation of lithium battery negative electrode materials, in particular to a method for testing the mixing uniformity of lithium battery negative electrode materials. Background technique [0002] In the existing lithium battery production process, it is necessary to mix the negative electrode material graphite and conductive carbon evenly, but whether graphite and conductive carbon are mixed uniformly, there is currently no accurate and quantitative characterization method. [0003] CN102661911A discloses a method for quickly detecting the mixing uniformity of powder materials. First, understand the various properties of the mixed materials, then take samples after mixing, and then calculate the deviation value through calculation, and then evaluate according to the size of the deviation value. When the deviation When the value is not greater than 10%, it is considered that the material has been mixed evenly. I...

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Problems solved by technology

[0003] CN102661911A discloses a method for quickly detecting the mixing uniformity of powder materials. First, understand the various properties of the mixed materials, then take samples after mixing, and then calculate the deviation value through calculation, and then evaluate according to the size of the deviation value. When the deviation When the value is not greater than 10%, it is considered that the material has been mixed evenly. If it is greater than 10%, it is necessary to continue mixing again, and then re-sampling and testing until the required deviation is reached; this scheme has the problems of complicated testing process and insufficient accuracy.

[0004] CN106404584A discloses a method for evaluating the uniformity of dry-mixing of lithium-ion battery powder, specifically adding dry powder materials and magnetic iron powder in the lithium-ion battery slurry to the mixer in turn for stirring; randomly taking out n parts of powder samples, each Each powder sample is weighed separately, and the magnetic iron powder in each powder sample is absorbed by a Gaussian magnetic rod, and then the remaining sample is weighed, and then the coefficient of variation of the mixing uniformity of the material is calculated according to the formula; If the obtained coefficient of variation CV is less than 10%, the dry mixing uniformity of the lithium-ion battery slurry powder is good; and the smaller the coefficient of variation, the more uniform the dry-mixing of the lithium-ion battery slurry powder. Defects in testing the homogeneity of mixtures containing magnetic materials in samples

[0005] Although the above-mentioned documents disclose some test methods for testing the mixing uniformity of materials, there are still problems that the test process is complicated and only applicable to the test of mixtures containing magnetic materials. Therefore, it is simple to develop a test method with high accuracy. And the test method suitable for the mixing uniformity test of lithium battery anode materials is still of great significance

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