Lithium ion battery, negative plate thereof and preparation method thereof

A technology for lithium-ion batteries and negative plates, applied in battery electrodes, non-aqueous electrolyte storage battery electrodes, circuits, etc., can solve the problems of deterioration of charge and discharge performance of carbon-based active materials, achieve good low-temperature discharge performance and high-temperature cycle performance, and good Electrochemical performance, the effect of improving the adhesion force

Active Publication Date: 2016-02-03
NINGDE AMPEREX TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In view of the problems existing in the background technology, the object of the present invention is to provide a lithium-ion battery and its negative electrode sheet and preparation method, the negative electrode sheet has not only improved the cohesion between the particles of silicon-based a

Method used

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  • Lithium ion battery, negative plate thereof and preparation method thereof

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preparation example Construction

[0019] According to the preparation method of the negative electrode sheet of the lithium ion battery of the second aspect of the present invention, it is used to prepare the negative electrode sheet of the lithium ion battery of the first aspect of the present invention, comprising the steps: (1) silicon-based active material, first conductive agent, The first binder is added to the solvent deionized water in proportion to stir and mix evenly, then the pH value is adjusted to be less than 7, and then the temperature is raised and the stirring is continued to make the solid content of the slurry reach the specified value, and the first slurry is obtained, wherein the silicon-based active material The surface of the surface contains -OH, and the first binder includes at least a binder containing -COOM, wherein M is selected from one of H, Li, Na, K, Mg, Al, Ca, Zn; (2) the The carbon-based active material, the second conductive agent, and the second binder are added in proportio...

Embodiment 1

[0036] 1. Preparation of Negative Electrode for Lithium-ion Batteries

[0037] (1) Add silicon particles with a silicon-based active material D50 of 3 μm, the first conductive agent SuperP, and polyacrylic acid with a molecular weight of 400,000 as the first binder in a mass ratio of 96:1:3 to the solvent deionized water, and stir well to mix evenly , then use oxalic acid to adjust the pH value of the slurry to 3, then slowly raise the temperature of the slurry to 60°C and continue to stir until the solid content of the slurry is 70%, to obtain the first slurry, wherein the surface of the silicon particles contains -OH ;

[0038] (2) Add artificial graphite with a carbon-based active material D50 of 15 μm, the second conductive agent SuperP, and polyacrylic acid with a molecular weight of the second binder of 400,000 in a mass ratio of 98:1:1 into the solvent deionized water, fully stir and mix evenly , forming a second slurry with a solid content of 48%;

[0039] (3) The se...

Embodiment 2

[0048] Lithium-ion batteries were prepared according to the method of Example 1, except for the following differences:

[0049] 1. Preparation of Negative Electrode for Lithium-ion Batteries

[0050] (1) The silicon-based active material is SiO1.1 with a D50 of 3 μm, the surface of SiO1.1 contains -OH, and the first binder is lithium polyacrylate with a molecular weight of 800,000;

[0051] (2) The carbon-based active material is carbon nanotubes, and the second binder is lithium polyacrylate with a molecular weight of 800,000.

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Abstract

The invention provides a lithium ion battery, a negative plate thereof and a preparation method thereof. The negative plate comprises a negative electrode current collector, and a negative film which is arranged on the negative electrode current collector and comprises a negative electrode active material, a negative electrode adhesive and a conductive agent of the negative electrode. The negative electrode active material comprises a silicon-based active material and a carbon-based active material; the negative electrode adhesive is distributed on the surface of the negative electrode active material; the surface of the silicon-based active material contains -OH; the negative electrode adhesive at least comprises a -COOM adhesive; and the mass ratio of the negative electrode adhesive distributed on the surface of the silicon-based active material to the silicon-based active material is larger than the mass ratio of the negative electrode adhesive distributed on the surface of the carbon-based active material to the carbon-based active material. The negative plate provided by the invention is used for improving the binding power of granules of the silicon-based active material and can solve the problem that the charge and discharge performance of the carbon-based active material is deteriorated due to excessive negative electrode adhesive. The lithium ion battery provided by the invention has good low temperature discharge performance and high temperature cycling performance.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a lithium ion battery, a negative electrode sheet thereof and a preparation method thereof. Background technique [0002] Due to the characteristics of high energy density, long life, low self-discharge, and no memory effect, lithium-ion batteries are widely used in portable electronic products such as mobile phones, notebook computers, and digital cameras. However, the rapid development of miniaturization, intelligence and multi-function of various portable electronic products has put forward higher requirements on the energy density of lithium-ion batteries. [0003] At present, lithium-ion batteries mainly use graphite-based carbon-based active materials as negative electrode active materials. The low gram capacity of carbon-based active materials limits the further improvement of the energy density of lithium-ion batteries. Compared with carbon-based active materials, sili...

Claims

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Application Information

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IPC IPC(8): H01M4/13H01M4/139
CPCY02E60/10
Inventor 张小文牛少军何东铭蒋晨曦申红光
Owner NINGDE AMPEREX TECH
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