Secondary lithium ionic cell and preparation method of cathode pole piece thereof

A lithium-ion battery and negative pole piece technology, which is applied in secondary batteries, electrode manufacturing, active material electrodes, etc., can solve problems such as uneven distribution of coatings, protection of the inner layer, and lack of contact resistance on the surface of the negative pole piece.

Active Publication Date: 2008-04-09
NINGDE AMPEREX TECH
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  • Abstract
  • Description
  • Claims
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Problems solved by technology

[0004] The purpose of the present invention is to overcome the problem that the porosity of the surface layer is less than the porosity of the inner layer due to the uneven distribution of the coating on the negative electrod

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  • Secondary lithium ionic cell and preparation method of cathode pole piece thereof

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Embodiment Construction

[0016] Referring to Fig. 1, artificial graphite FSNC, conductive carbon Super-P, carboxymethyl cellulose sodium CMC (a kind of thickener), styrene-butadiene rubber SBR (a kind of thickener), according to the ratio A that is 94.5:1.5 : 1.5: 2.5 mixed with deionized water and stirred evenly to obtain negative electrode coating slurry a, during the stirring process, the viscosity was adjusted by deionized water, and then the slurry a was coated on both sides of the negative electrode current collector (copper foil) 1, Form the first diaphragm layer 2 (i.e. the inner diaphragm layer), and after simple cold pressing, a kind of mesophase carbon microsphere graphite MCMB, aluminum oxide Al 2 o 3 , carboxymethyl cellulose sodium CMC (a kind of thickener), styrene-butadiene rubber SBR (a kind of thickener), according to proportion B namely 90.5: 5.5: 1.5: 2.5 is mixed with deionized water and stirred evenly to obtain negative electrode Slurry b was coated and the viscosity was adjuste...

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Abstract

The invention relates to a secondary Li-ion battery and a method of preparing a negative pole piece thereof. The paste containing different negative active materials or the paste of different ratios are coated by level on the two sides of a negative current collector respectively according to a certain order to form a plurality of negative diaphragm layers, and different thickness can be used for each diaphragm layer. By controlling different active materials, ratio solutions and coating thicknesses, the change of the porosity and the resistance of each layer is controlled, the porosity of the surface diaphragm layers can be larger than that of the inner diaphragm layers, which prevents the penetration of the electrolyte in the internal core and enhances the performance of the core, and by adjusting the resistance of the surface diaphragm layers, the surface contact resistance is increased to have a function of protecting the inner diaphragm layers. Then, by the processes of cold pressing, striping, welding terminals and so on, the negative pole piece is fabricated, and thereby the secondary Li-ion battery containing the negative pole piece is fabricated.

Description

Technical field: [0001] The invention relates to the technical field of lithium ion batteries, in particular to a preparation method of a secondary lithium ion battery and its negative electrode sheet. Background technique: [0002] With the development of modern society, mobile devices such as video cameras, notebook computers, mobile DVDs and digital cameras have been more and more widely used, thus forming a large demand for high-energy batteries. At the same time, due to the miniaturization of modern electronic devices, High demands are placed on the safety and performance of high-energy batteries. As a high-energy battery, the battery cell of a secondary lithium-ion battery generally includes positive and negative pole pieces and a separator isolated therein. These three layers of materials are wound or laminated to make the battery core. [0003] In the current preparation method of lithium-ion battery negative electrode sheet, a layer of slurry of a certain quality i...

Claims

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Application Information

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IPC IPC(8): H01M4/02H01M4/04H01M10/40
CPCY02E60/122Y02E60/10
Inventor 王岳利周中心吴凯陈卫
Owner NINGDE AMPEREX TECH
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