Lithium ion battery cathode sheet and preparation method thereof, and lithium ion battery

A technology of lithium-ion batteries and negative electrodes, which is applied in the direction of electrode manufacturing, secondary batteries, active material electrodes, etc., can solve the problems of negative electrode active materials falling off and breaking, and achieve the ability to improve intercalation/delithiation, contact improvement, and cycle The effect of performance improvement

Inactive Publication Date: 2009-03-04
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The first purpose of the present invention is to overcome the shortcomings of poor contact between the negative electrode sheet of the existing lithium ion battery and the electrolyte, and the volume change during intercalation / delithiation that causes the negative electrode active material to fall off and break. / The volume change during delithiation will not cause the negative electrode active material to fall off and the lithium ion battery negative plate that is broken

Method used

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  • Lithium ion battery cathode sheet and preparation method thereof, and lithium ion battery
  • Lithium ion battery cathode sheet and preparation method thereof, and lithium ion battery
  • Lithium ion battery cathode sheet and preparation method thereof, and lithium ion battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0045] This embodiment is used to illustrate the lithium ion battery negative electrode sheet provided by the present invention and the lithium ion battery containing the negative electrode sheet.

[0046] (1) Preparation of positive electrode sheet

[0047] 100 parts by weight of LiFePO with a particle diameter of 0.5 microns 4 (produced by Tianjin Leading Company), 5 parts by weight of binder polyvinylidene fluoride (PVDF), 8 parts by weight of conductive agent acetylene black join in 80 parts by weight of N-methylpyrrolidone (NMP), then stir in vacuum mixer A cathode active material slurry was obtained. The obtained cathode active material slurry is coated on a wide aluminum foil with a width of 400 mm and a thickness of 20 microns, and the thickness of both sides is 150 microns; then, vacuum-dry at 100 ° C, and cut into 43.5 mm x 31 mm positive plate A1.

[0048] (2) Preparation of negative electrode sheet

[0049] Weigh 100 parts by weight of N-methylpyrrolidone (NMP)...

Embodiment 2

[0056] This embodiment is used to illustrate the lithium ion battery negative electrode sheet provided by the present invention and the lithium ion battery containing the negative electrode sheet.

[0057] (1) Preparation of positive electrode sheet

[0058] 100 parts by weight of LiFePO with a particle diameter of 0.5 microns 4 (produced by Tianjin Leading Company), 5 parts by weight of binder polyvinylidene fluoride (PVDF), 8 parts by weight of conductive agent acetylene black join in 80 parts by weight of N-methylpyrrolidone (NMP), then stir in vacuum mixer A cathode active material slurry was obtained. The obtained cathode active material slurry is coated on a wide aluminum foil with a width of 400 mm and a thickness of 20 microns, and the thickness of both sides is 155 microns; then, it is vacuum-dried at 100 ° C and cut into 43.5 mm x 31 mm positive sheet A2.

[0059] (2) Preparation of negative electrode sheet

[0060] The natural graphite of 100 parts by weight of ...

Embodiment 3-4

[0064] Cycle performance test

[0065] The lithium-ion batteries D1-D2 prepared in the above-mentioned Examples 1-2 were subjected to a cycle performance test. The specific steps were to charge to 3.8 volts with a current of 1 CmA, and charge at a constant voltage after the voltage rose to 3.8 volts, with a cut-off current of 0.05 CmA , rest for 5 minutes; the battery is discharged to 2.0 volts with 1CmA current, and rest for 5 minutes. Repeat the above steps 100 times to obtain the capacity of the battery after 100 cycles of 1CmA current discharge to 2.0 volts, and calculate the capacity maintenance rate before and after the cycle. The results are shown in Table 1.

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Abstract

The invention provides a negative electrode piece of a lithium battery, which comprises a negative current collector and negative active materials coated on the negative current collector; wherein, the surface of the negative current collector consists of a plurality of coated parts and uncoated parts; and the coated parts are separated by the uncoated parts. The invention also provides a method for preparing negative electrodes as well as the lithium battery with the negative electrode piece. The negative electrode piece is well contacted with the electrolyte and the negative active materials are unlikely to drop or get broken during the lithium intercalation and de-intercalation, thus greatly improving the cyclic performance and specific capacity of the lithium batteries with the negative electrode pieces.

Description

technical field [0001] The invention relates to a battery negative electrode sheet, a preparation method thereof and a battery, more precisely, to a lithium ion battery negative electrode sheet, a preparation method thereof and a lithium ion battery. Background technique [0002] In recent years, the development of high-tech electronics industry has been able to provide miniaturized and light-weight electronic equipment, which has led to the widespread use of more and more portable electronic equipment, and lithium-ion batteries are known for their high discharge voltage, high energy density and cycle The advantage of long service life becomes the preferred energy source for these portable electronic devices. [0003] Lithium-ion battery cell is mainly composed of positive electrode sheet, negative electrode sheet, separator and electrolyte. The performance of negative electrode sheet has a great influence on the performance of lithium-ion battery. The performance of said ne...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/02H01M4/04H01M10/40
CPCY02E60/122Y02E60/10
Inventor 梁康群陈炎梁桂海李仲姜占锋
Owner BYD CO LTD
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