Positive plate and lithium ion battery comprising positive plate

A positive electrode sheet and positive electrode technology, applied in the direction of positive electrodes, battery electrodes, secondary batteries, etc., can solve problems such as fire failure

Inactive Publication Date: 2021-03-30
ZHUHAI COSMX BATTERY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The present invention provides a positive electrode sheet and a lithium ion battery including the positive electrode sheet. The use of the positive electrode sheet can solve the problems of lithium ion battery fire and failure in the case of mechanical abuse, and improve the safety performance of the lith

Method used

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  • Positive plate and lithium ion battery comprising positive plate
  • Positive plate and lithium ion battery comprising positive plate
  • Positive plate and lithium ion battery comprising positive plate

Examples

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preparation example Construction

[0064] The present invention also provides a method for preparing the above positive electrode sheet, the method comprising the following steps:

[0065] 1) preparing the slurry forming the first coating and the slurry forming the second coating respectively;

[0066] 2) Coating the slurry for forming the first coating layer and the slurry for forming the second coating layer on both surfaces of the positive electrode current collector to prepare the positive electrode sheet.

[0067] According to the present invention, in step 2), the coating is double layer coating, gravure coating, extrusion coating, transfer coating.

[0068] Exemplarily, step 2) specifically includes the following steps:

[0069] Coating the slurry for forming the first coating on the surface of the positive electrode collector to form the first coating, and coating the slurry for forming the second coating on the surface of the first coating to form the second coating to obtain a positive electrode shee...

Embodiment 1

[0089] The first step: prepare the first coating slurry, mix 80wt% lithium iron phosphate (LFP), 15wt% modified PVDF, 5wt% carbon black, add NMP, and prepare the slurry by stirring.

[0090] The second step: preparing the second coating slurry, mixing 97wt% lithium cobaltate, 1wt% conductive carbon black, 0.8wt% carbon nanotubes, 1.2wt% PVDF, adding NMP, and stirring to prepare a slurry.

[0091] The third step: preparing negative electrode slurry, mixing 96wt% artificial graphite, 1wt% conductive carbon black, 1.5wt% SBR and 1.5wt% CMC, adding deionized water, and stirring to prepare a slurry.

[0092] Step 4: Preparation of the positive electrode sheet. Use the extrusion coating process to coat the first coating slurry in step 1 on the surface of the positive electrode current collector to form a first coating with a thickness of 5 μm, and apply the second coating in step 2 The slurry was coated on the surface of the first coating to form a second coating with a thickness of...

Embodiment 2-9

[0097] The other steps are the same as in Example 1, except that the selection and content of each material in the first step are different, and / or the selection and content of each material in the second step are different, as shown in Table 1.

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Abstract

The invention provides a positive plate and a lithium ion battery comprising the positive plate. The positive plate comprises a positive current collector and a positive coating, and the positive coating comprises a first coating and a second coating. The surface of the positive electrode current collector is coated with the first coating, and the surface of the first coating is coated with the second coating; the first coating comprises an inorganic filler, a first conductive agent and a first binder, and the second coating comprises a positive active material, a second conductive agent and asecond binder. When the relationship X<1>/(Y<1>*SY<1>+Z<1>*SZ<1>) > X<2>/(Y<2>* SY<2>+Z<2>*SZ<2> is satisfied, the lithium ion battery has good safety performance, and the probability of fire failureof the battery is greatly reduced when mechanical abuse (acupuncture and heavy impact) occurs. And meanwhile, the cycle performance of the lithium ion battery is not influenced and is equivalent to the cycle performance effect of the existing lithium ion battery, namely, the safety performance of the lithium ion battery is remarkably improved on the premise of keeping the cycle performance of thelithium ion battery.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a positive electrode sheet and a lithium ion battery including the positive electrode sheet. Background technique [0002] Lithium-ion batteries are widely used in smartphones, laptops, Bluetooth, wearable devices and other fields due to their advantages such as high platform voltage, high energy density, no memory effect, and long life. However, in some extreme cases, such as when the lithium-ion battery is subjected to mechanical damage (needle puncture, heavy impact, etc.), an internal short circuit will occur, and a lithium-ion battery with an internal short circuit will emit a large amount of heat in a short period of time, causing the battery Failure to catch fire has a great potential safety hazard. [0003] Studies have found that when an internal short circuit occurs in a lithium-ion battery, there will be multiple short-circuit modes, among wh...

Claims

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Application Information

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IPC IPC(8): H01M4/131H01M4/1391H01M4/36H01M4/525H01M4/58H01M10/0525
CPCH01M4/131H01M4/1391H01M4/366H01M4/364H01M4/525H01M4/5825H01M10/0525H01M2004/028Y02E60/10
Inventor 张健彭冲李俊义徐延铭
Owner ZHUHAI COSMX BATTERY CO LTD
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