Preparation method of lithium ion battery pole piece

Abstract

The invention provides a preparation method of a lithium ion battery pole piece. The preparation method comprises the following steps: 1) providing a current collector, and sticking a thermal expansion foaming pressure sensitive adhesive tape or coating a thermal expansion forming adhesive at the preset position of a plug on the current collector, and forming a peelable adhesive sheet; 2) coating an active substance sizing agent on the current collector, and forming an active substance diaphragm layer; 3) drying the active substance diaphragm layer under the foaming expansion temperature of the adhesive sheet, carrying out thermal expansion foaming on the adhesive sheet in a drying process so as to be separated from the current collector, and forming an active substance hollow-out area in which the diaphragm layer is not covered with active substances on the current collector; and 4) fixing the lug on the current collector that the active substance hollow-out area is exposed out to obtain the required pole piece. Compared with the prior art, the pole piece prepared by the preparation method makes full use of the area of the current collector, and the increase of battery thickness is reduced, so that a lithium ion battery prepared by using the pole piece has relatively high volume energy density and relatively low battery internal resistance.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, more specifically, to a preparation method of lithium ion battery pole pieces. Background technique [0002] Since the promotion of commercialization, lithium-ion batteries have been widely used as a variety of portable batteries due to their advantages such as high energy density, high working voltage, long cycle life, no memory effect, green environmental protection, and flexible design of size and shape according to actual needs. The power supply of electronic appliances; these broad application fields and various actual needs have in turn greatly promoted the development of lithium-ion batteries. [0003] The rapid development of mobile electronic and electrical equipment requires lithium-ion batteries that provide power for these thin, portable and powerful devices to have higher capacity (ie, volumetric energy density); however, the energy density and operating voltage of lithium-ion ba...

AI Technical Summary

Problems solved by technology

Due to the fabrication of electrode sheets in this assembly method, a certain length is usually reserved at the end of the current collector 12, and a blank area that is not coated with the active material membrane layer 11 is welded to the blank area of ​​the current collector 12. area, thus resulting in a reduction in the utilization rate of the battery electrode area

Taking a thin lithium-ion battery with a thickness of 1.0mm, a width of 66mm, and a length of 125mm as an example, the battery pole piece with the above-mentioned traditional winding structure has a ratio of the area of ​​the positive electrode active material membrane layer to the area of ​​the positive electrode current collector aluminum foil. %, it can be seen that the area utilization of the current collector 12 is very low, which in turn leads to a low volumetric energy density of the lithium-ion battery

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