Battery pole piece resistivity test method

Abstract

The present invention provides a battery pole piece resistivity test method. The method comprises the following steps of: putting a battery pole piece sample comprising a carrier and a coating layer coating on the carrier onto a sample cutting machine to cut off and get a sample; putting the sample on a platform deck, fixing the sample onto the platform deck through adhesive and leaving a free end; applying an external force to the free end to allow the carrier of the sample to separate from the coating layer and to allow the coating layer to stay on the adhesive; and performing resistivity test of the coating layer staying on the adhesive to obtain the resistivity of the coating layer. The battery pole piece resistivity test method can accurately test the resistivity of the coating layerso as to find the battery pole piece with the optimal compacted density and improve the performances of the battery.

Description

【Technical field】 [0001] The invention relates to the technical field of batteries, in particular to a method for testing the resistivity of battery pole pieces. 【Background technique】 [0002] During the manufacturing process of lithium-ion power batteries, the compaction density has a great influence on the performance of the battery. For example, if the compaction density is too large, the porosity and surface area of ​​the electrode will decrease, which is not conducive to the diffusion of lithium ions, but the conductivity will increase. The ohmic internal resistance decreases; on the contrary, if the electrode compaction density is too small, the porosity and surface area will increase, which is conducive to the diffusion of lithium ions, but the conductivity decreases and the ohmic internal resistance increases. Therefore, in the battery manufacturing process , finding the optimum compaction density is important for the performance of the battery. [0003] The existi...

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Problems solved by technology

[0003] The existing test method of compaction density is to observe the surface morphology of the pole piece by scanning electron microscope (SEM) and to test the electrolyte liquid absorption rate of the pole piece to characterize it. However, this method cannot measure the resistance of pole pieces with different compaction densities. For example, if the dressing is coated on a polytetrafluoroethylene plate, since the four-probe resistivity meter cannot be used for rolling treatment before testing, only the resistivity before rolling can be tested, and the resistivity is often biased. high

In addition, if the dressing is applied to the carrier to obtain pole pieces with different compaction densities, then the four-probe test is performed. Since the carrier is a conductor, the resistivity of the test is low and the reliability is not high. Therefore, the best compaction cannot be screened out. Density pole pieces to improve battery performance

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