Negative electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery

A non-aqueous electrolyte, secondary battery technology, applied in non-aqueous electrolyte battery electrodes, battery electrodes, circuits, etc., can solve problems such as battery capacity reduction, and achieve the effect of high capacity and good fast charge and discharge performance

Pending Publication Date: 2022-07-26
PANASONIC ENERGY CO LTD MORIGUCHI SHI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when the negative electrode active material is composed only of graphite with a high true density, there is a problem that the battery capacity decreases due to repeated charging and discharging.

Method used

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  • Negative electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery
  • Negative electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery
  • Negative electrode for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0060] [Production of positive electrode]

[0061] As the positive electrode active material, lithium cobaltate (LiCoO) containing zirconium, magnesium, and aluminum was used. 0.979 Zr 0.001 Mg 0.01 Al 0.01 O 2 ). The above-mentioned positive electrode active material was mixed so that 95 parts by mass of the positive electrode active material, 2.5 parts by mass of the carbon powder as the conductive agent, and 2.5 parts by mass of the polyvinylidene fluoride powder as the binder were added, and an appropriate amount of N-methyl-2- Pyrrolidone (NMP) to prepare positive electrode mixture slurry. This slurry was applied to both sides of a positive electrode current collector made of aluminum foil (thickness: 15 μm) by a doctor blade method, the coating film was dried, and then the coating film was rolled with a calendering roll to produce a positive electrode current collector formed on both sides of the The positive electrode of the positive electrode mixture layer.

[0...

Embodiment 2、4

[0074]

[0075] As shown in Table 1, a non-aqueous electrolyte secondary battery was produced in the same manner as in Example 1, except that the mass ratio of the first negative electrode mixture layer and the second negative electrode mixture layer was changed.

Embodiment 3

[0077] A non-aqueous electrolyte secondary battery was produced in the same manner as in Example 2, except that the negative electrode active material C produced by mixing the carbon material C and SiO produced as follows was used instead of the negative electrode active material B.

[0078] [Production of carbon material C]

[0079] The coke was pulverized until the average particle diameter became 13 μm, and pitch as a binder was added to the pulverized coke to aggregate the coke until the average particle diameter became 18 μm. After firing the aggregate at a temperature of 1050°C, it was sieved using a 250-mesh sieve to obtain a carbon material C having an average particle diameter of 18 μm. The true density of the produced carbon material C was 1.9 g / cm as a result of measurement by the pycnometer method 3 .

[0080]

[0081] A nonaqueous electrolyte secondary battery was produced in the same manner as in Example 1, except that a single negative electrode mixture laye...

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Abstract

The purpose of the present application is to provide a non-aqueous electrolyte secondary battery having high capacity and good rapid charge / discharge performance. A negative electrode for a non-aqueous electrolyte secondary battery according to one embodiment of the present application is provided with: a negative electrode current collector; a first negative electrode mixture layer provided on the surface of the negative electrode current collector; and a second negative electrode mixture layer provided on the surface of the first negative electrode mixture layer. The first negative electrode mixture layer contains a first carbon material having a true density of 2.1 g / cm3 to 2.3 g / cm3, the second negative electrode mixture layer contains a second carbon material having a true density of 1.5 g / cm3 to 2.0 g / cm3, the interparticle porosity of the second carbon material in the second negative electrode mixture layer is greater than the interparticle porosity of the first carbon material in the first negative electrode mixture layer, and the mass ratio of the first negative electrode mixture layer to the second negative electrode mixture layer is 95: 5 to 80: 20.

Description

technical field [0001] The present application relates to a negative electrode for a non-aqueous electrolyte secondary battery, and a non-aqueous electrolyte secondary battery. Background technique [0002] In order to increase the energy density of the non-aqueous electrolyte secondary battery, graphite with high true density may be used as the negative electrode active material. However, when the negative electrode active material is composed of only graphite with a high true density, there is a problem that the battery capacity decreases due to repeated charging and discharging. [0003] For example, Patent Documents 1 and 2 disclose a method of suppressing a decrease in battery capacity due to charge-discharge cycles by using a mixed material of graphite and a non-graphitic carbon material having a lower true density than graphite as a negative electrode active material. [0004] prior art literature [0005] Patent Literature [0006] Patent Document 1: Japanese Pate...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/133H01M4/13H01M4/134H01M4/36H01M4/38H01M4/48H01M4/587
CPCH01M4/587H01M4/134H01M4/133Y02E60/10H01M10/0525H01M4/1393H01M4/131H01M4/525H01M4/505H01M4/52H01M4/362H01M10/0422H01M2004/021H01M4/386Y02P70/50H01M4/364H01M4/366H01M4/483H01M2004/027
Inventor 田下敬光水越文一加藤木晶大
Owner PANASONIC ENERGY CO LTD MORIGUCHI SHI
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