A kind of method of deep drying lithium ion battery powder material

Abstract

The invention relates to a microporous container used for deeply drying lithium ion battery powder materials and a deep drying method. The pore diameters of micro pores of the microporous container are smaller than or equal to the average grain diameter of the lithium ion battery powder materials, and the microporous container is resistant to the drying temperature equal to or smaller than 300 DEG C, so that it is ensured that the materials are basically not leaked under the high vacuum degree smaller than 100 Pa, and the material receiving rate approaches to 100%. According to the deep drying method, the powder materials are packaged in the microporous container which is placed in vacuum drying equipment, circulating thermal-conducting drying gas is led into the container to heat the materials, and heat preserving and preheating are carried out; then vacuumizing is carried out to reach the preset ultrahigh vacuum degree, drying is carried out, and circulating cold-conducting drying gas is led into the container for cooling; and then the container is transferred to a low-dew-point-value environment connected with the drying equipment in series, the materials are taken out, and sealing and storing are carried out. By means of the deep drying method, the lithium ion battery electrode materials with ultralow water content which is hard to achieve under conventional drying conditions can be obtained, and the method has important application value.

Description

technical field [0001] The invention relates to the field of powder material processing, in particular to a method for deep drying of powder materials, in particular to a method for deep drying of lithium ion battery powder materials. Background technique [0002] As new energy vehicles have higher and higher requirements for the electrochemical performance and safety performance of lithium-ion power batteries, the requirements for the constituent materials of organic electrolyte lithium-ion batteries and the moisture control in the battery manufacturing process are also becoming more and more stringent. Since the moisture in the battery will undergo a series of chemical reactions with the electrolyte components during the charging and discharging process of the battery: 1) H 2 O gets electrons and decomposes to produce OH - and H 2 ;OH - with Li in the electrolyte + The reaction generates solid LiOH; LiOH further gains electrons and combines with Li + The reaction prod...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the drying degree is limited and uneven, the air consumption is large, and the cooling time takes a long time

The vacuum drying of the mixing tank specifically refers to the method of putting the powder to be dried into a jacketed mixing tank, continuing to vacuumize and injecting a certain temperature of heat-conducting oil into the jacket to dry the powder; although this method does not Air consumption, and with the slow rotation of the kettle body, the drying is relatively uniform, but the disadvantages are: (1) 1-4% of the powder is sucked away during the continuous vacuuming of the material, resulting in material loss; (2) The cooling period of the hot oil is long; although the cooling and heating oil circuit parallel mixing kettle disclosed in the Chinese patent CN104634092A shortens the cooling time of the mixing kettle to a certain extent when the lithium battery powder material is cooled, it is slightly slow due to the switching of the hot and cold oil. complex, so that the whole drying process still takes a long time; (3) the degree of vacuum is generally only 4000-10000Pa, resulting in the moisture absorbed inside the dried powder material still cannot escape; (4) the transfer and removal of dry materials There is no protective measure for the material, which makes some hygroscopic materials absorb water again during the transfer packaging process

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