Pole piece of lithium ion cell and method to manufacture cell

A lithium-ion battery and pole piece technology, which is applied in the field of lithium-ion battery pole piece and the preparation of the lithium-ion battery, can solve the problems of battery cycle performance, uneven distribution of battery capacity, unstable product quality, etc. Achieve the effect of stable cycle performance, narrow distribution range and extended service life

Active Publication Date: 2007-05-16
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although according to the needs of different types of batteries, the required thickness of the pole piece within the requirements of the process standard can be obtained by controlling the pressure, but after the above-mentioned pole piece is used to prepare the battery, it is found that the obtained battery capacity is unevenly distributed and the distribution range is very wide. And the cycle performance of the battery is good or bad, and the product quality is unstable

Method used

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  • Pole piece of lithium ion cell and method to manufacture cell

Examples

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preparation example Construction

[0012] According to the preparation method of the lithium-ion battery provided by the present invention, preferably, the current collector containing the positive electrode active material, the conductive agent and the positive electrode binder and the collector containing the negative electrode active material and the negative electrode binder after drying Calendering is carried out, the calendering includes passing the pole piece through the gap between the two rollers of the calender, and applying pressure on the pole piece through the rollers, wherein, before applying the pressure, first adjust the two rollers of the calender Roller roller clearance, make 1 / 2(D 2 +D 1 )2 +9D 1 ), preferably 1 / 3 (D 2 +2D 1 )≤X≤1 / 7(D 2 +6D1); In the formula, X is the roller gap between the two rollers of the calender, D 1 is the thickness of the front pole piece passing through the gap between the two rollers of the calender, D 2 It is the thickness of the back pole piece passing throu...

Embodiment 1

[0032] This example is used to illustrate the preparation of the lithium ion secondary battery provided by the present invention.

[0033] (1) Preparation of positive electrode

[0034] 100 g of the positive active ingredient LiCoO 2 1. Add 3 grams of binder polyvinylidene fluoride and 3 grams of conductive agent acetylene black into 50 grams of N-methylpyrrolidone, and then stir in a mixer to form a uniform positive electrode slurry.

[0035] The slurry was evenly coated on both sides on an aluminum foil with a thickness of 16 μm, dried at 150° C., and cut to obtain a positive electrode sheet with a size of 340×41.5×0.205 mm. Then, the pole piece was rolled on the calender. Before the rolling, the roller gap X between the two rollers was adjusted so that X=0.196 mm. After the calendering, a positive pole piece with a thickness of 0.145 mm was obtained. It contains 5.8 grams of active ingredient LiCoO 2 .

[0036] (2) Preparation of negative electrode

[0037] Add 100 gra...

Embodiment 2-5

[0042] This example is used to illustrate the preparation of the lithium ion secondary battery provided by the present invention.

[0043] Prepare the battery pole piece and the battery according to the method of Example 1, the difference is that before the positive pole piece is rolled, the roller gap X between the two rollers is adjusted so that X = 0.195 mm, 0.193 mm, 0.190 mm respectively mm, 0.185 mm; before calendering the negative electrode sheet, adjust the roller gap X between the two rollers so that X = 0.198 mm, 0.195 mm, 0.192 mm, 0.186 mm respectively. Square aluminum shell lithium-ion secondary batteries 043450A3B4-B6, 043450A3B7-B8, 043450A3B10-B12, and 043450A3B13-B15 with a size of 50×34×4.5 mm were prepared respectively.

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Abstract

The preparation method for Li-ion cell plate comprises: coating and / or filling slurry contained active material on a collector body; drying, flattening by making plate pass gap between two rollers; wherein, before flattening, adjusting roller gap of two calenders as 1 / 2(D2+D1) <X<=1 / 10(D2+9D1); where, X for roller gap, D1 / D2 for plate thickness before / after flattening. This invention can control plate thickness precisely, and prolongs cell service time.

Description

technical field [0001] The invention relates to a battery pole piece and a method for preparing the battery, and more specifically relates to a lithium-ion battery pole piece and a preparation method for the lithium-ion battery. Background technique [0002] In recent years, miniaturized lithium-ion secondary batteries have become more and more perfect, and are now widely used in portable electronic and communication equipment such as small cameras, mobile phones, and notebook computers. Due to environmental and other reasons, the market for electric bicycles and electric vehicles is also developing rapidly. Lithium-ion batteries have become the preferred energy source for the aforementioned power devices due to their high discharge voltage, high energy density, and long cycle life. [0003] In the manufacture process of lithium-ion battery, the preparation method of pole sheet comprises coating and / or filling the slurry containing positive electrode active material, conduct...

Claims

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Application Information

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IPC IPC(8): H01M4/04H01M10/38H01M10/40H01M4/139H01M10/058
CPCY02E60/122Y02E60/10Y02P70/50
Inventor 肖峰沈河生张才毓
Owner BYD CO LTD
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