Battery cathode and lithium ion secondary battery comprising same

A secondary battery and lithium ion technology, applied in secondary batteries, battery electrodes, electrode manufacturing, etc., can solve the problems of high battery capacity and good battery cycle performance, and achieve improved cycle performance and high-current discharge performance, The effect of high specific capacity and good cycle performance

Active Publication Date: 2008-06-04
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0014] The purpose of the present invention is to overcome the disadvantage that the negative electrode of the existing lithium ion secondary battery cannot take into account the high capacity and good battery cycle performance of the battery, and provide a negative electrode that makes the lithium ion secondary battery have high capacity and good cycle performance

Method used

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  • Battery cathode and lithium ion secondary battery comprising same
  • Battery cathode and lithium ion secondary battery comprising same
  • Battery cathode and lithium ion secondary battery comprising same

Examples

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preparation example Construction

[0049]The method for preparing a battery negative electrode provided by the present invention includes coating and / or filling a slurry containing a negative electrode material on a current collector, drying, and rolling. The negative electrode material includes a negative electrode active material and a negative electrode binder. The active material is a mixed graphite of natural graphite and artificial graphite, wherein the natural graphite is spherical natural graphite, the artificial graphite is micro-particle flake-shaped artificial graphite, and the particle diameter of the spherical natural graphite is larger than the micro-particle flake-shaped artificial graphite The particle diameter of the spherical natural graphite and the median diameter D of the micro-particle scaly artificial graphite 50 The difference is 4-25 microns; the median diameter D of the micro-particle scaly artificial graphite 50 It is 0.3-6 microns; the weight ratio of the spherical natural graphite to th...

Embodiment 1

[0061] This embodiment illustrates the negative electrode provided by the present invention, a preparation method thereof, and a battery including the negative electrode.

[0062] (1) Preparation of negative electrode

[0063] Spherical natural graphite (product of Qingdao Taineng Company, median diameter D 50 It is 17.54 microns, the distance between the microcrystalline layers is d 002 The correction value is 0.33650 nm, and the specific surface area obtained by the low-temperature nitrogen adsorption BET method is 2.2 meters 2 / G) and micro-particle scaly artificial graphite (commodity of Changsha Xingcheng Company, median diameter D 50 It is 4.6 microns, the microcrystalline layer spacing d 002 The correction value is 0.33784 nm, and the specific surface area obtained by the low-temperature nitrogen adsorption BET method is 11.95 meters 2 / G) The mixed graphite is obtained after thorough mechanical mixing at a weight ratio of 1:0.2, which is ready for use.

[0064] Add 100 gra...

Embodiment 2-7

[0088] This embodiment illustrates the negative electrode provided by the present invention, a preparation method thereof, and a battery including the negative electrode.

[0089] The negative electrode and the battery A2-A7 including the negative electrode were prepared according to the method of Example 1. The difference is that the ratio of the negative electrode active material and the median diameter D 50 , As shown in Table 1 below.

[0090] Table 1

[0091]

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Abstract

The invention relates to a cathode of a lithium ion secondary battery, comprising a current collector and cathode material smeared over and/or filled in the current collector. The cathode material comprises cathode active substance and cathode adhesive. The cathode active substance is the mixture of a natural graphite and an artificial graphite, wherein, the natural graphite is the natural graphite with a ball shape, the artificial graphite is the artificial graphite with a micro granule scaly shape, the particle diameter of the natural graphite with the ball shape is longer than that of the artificial graphite with the micro granule scaly shape, the difference in value of the median diameter D50 between the natural graphite with the ball shape and the artificial graphite with the micro granule scaly shape is 4-25 microns; the median diameter D50 of the artificial graphite with the micro granule scaly shape is 0. 3-6 microns; the proportion by weight between the natural graphite with the ball shape and the artificial graphite with the micro granule scaly shape is 1:0.05-0.2. The lithium ion secondary battery provided by the invention has good circle performance and discharging performance with a large rate and safety performance under the condition of high capacity.

Description

Technical field [0001] The present invention relates to a battery negative electrode and a battery including the negative electrode. Specifically, the present invention relates to a battery negative electrode and a lithium ion secondary battery including the negative electrode. Background technique [0002] As a new type of chemical power source, lithium-ion secondary battery has the characteristics of high energy density, high voltage, no pollution, no metal lithium, high cycle life, no memory effect, fast charging speed, etc. It is widely used in 3C products and is also That is, personal computers, mobile phones, and personal wireless electronic devices such as portable CD players and PDAs. [0003] However, as people's demands continue to increase, high-capacity lithium ion secondary batteries have become the current development trend. In order to make lithium ion secondary batteries have higher capacity and excellent overall performance, the most fundamental way is to improve...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/02H01M4/58H01M4/04H01M10/40C01B31/04C01B31/00
CPCY02E60/122Y02E60/10
Inventor 刘卫平李科姜俊刚
Owner BYD CO LTD
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