Device and method for detecting moisture content of lithium battery pole piece

Abstract

The invention discloses a device and a method for detecting the moisture content of a lithium battery pole piece. The device includes a test instrument and a sealed test bottle allowing a to-be-tested sample pole piece to be placed therein. The sealed test bottle is communicated with a dry gas source and a reactor filled with a reagent respectively through gas pipelines. The test instrument is conductively connected to the reagent through a positive pole and a negative pole which are contacted with the reagent. In the device and the method for detecting the moisture content of a lithium battery pole piece, moisture in the pole piece is separated out by heating the pole piece for carrying out moisture content detection and the mass of the separated-out moisture is measured by chemical reaction so that the moisture content in a dried pole piece can be calculated. The method is simple in sampling, is easy to carry out, and allows situation of the moisture content of the pole piece to be directly detected, is high in accuracy of detection of the moisture content, and is simple in adjustment of quality controlling standard. In the method, quality control during a production process is monitored by detecting the moisture content in the dried pole piece, so that a convincing prove is provided for improvement of a drying technology and process control.

Description

technical field [0001] The invention relates to a method for detecting the water content of a pole piece, in particular to a device and method for detecting the water content of a lithium battery pole piece. Background technique [0002] For lithium batteries, moisture has a great impact on its quality. In severe cases, the product will be scrapped directly. The main reason is that the presence of moisture causes it to react with the electrolyte, which will mainly cause the following adverse consequences: (1) The battery used The electrolyte cannot be used in an environment with too much moisture. When filling the battery, it must be in an environment with a humidity of less than 1%, and seal it as soon as possible after filling to prevent the inside of the battery from being in contact with the air. If the moisture is too high, the electrolyte will react with the moisture to generate a small amount of harmful gas, which will have a negative impact on the environment of the...

AI Technical Summary

Problems solved by technology

If the moisture is too high, the electrolyte will react with the moisture to generate a small amount of harmful gas, which will have a negative impact on the environment of the liquid injection room; this will also affect the quality of the electrolyte itself, making the battery performance poor; it will also cause the battery rivets to rust; (2 ) Moisture will react with a component in the electrolyte to generate harmful gas

When there is enough moisture, a large amount of gas will be generated, causing the internal pressure of the battery to increase, causing the battery to bulge due to stress deformation, and this bulging phenomenon is basically plastic deformation. This deformation will have two effects. One is the product. The appearance size does not meet the requirements, and it cannot be assembled into a box; second, this deformation makes the internal pole pieces of the battery not directly bonded to the pole pieces, which affects the extraction and insertion of lithium ions, thereby affecting the capacity and cycle life of the battery, etc.; (3) When there is a lot of water inside the battery, the electrolyte inside the battery reacts with water, and the product will be gas and hydrofluoric acid. Hydrofluoric acid is a very corrosive acid, which can make the inside of the battery Metal parts corrode, which in turn causes the battery to eventually leak

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