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Negative electrode active material for lithium secondary battery and method for manufacturing same

A negative electrode active material and lithium secondary battery technology, applied in the direction of electrode manufacturing, battery electrodes, circuits, etc., can solve the problems of short circuit, unrealized cycle life and long life, and achieve the suppression of cracks and micronization, and the reduction of volume change , the effect of shrinkage reduction

Inactive Publication Date: 2014-08-20
SHOWA DENKO KK
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] On the other hand, it is known that when a negative electrode formed of metal Li is used in a lithium secondary battery, a high theoretical capacity can be obtained, but there is a significant disadvantage that the metal Li forms a dendrite on the negative electrode during charging. Precipitate, and continue to grow through repeated charge and discharge, and reach the positive side to cause an internal short circuit
[0009] However, in the negative electrodes formed of the negative electrode active materials described in Patent Documents 1 and 2, although a large initial discharge capacity is obtained, the expansion and contraction of the negative electrode generated during repeated charge and discharge cannot be effectively suppressed. Cracks and micronization of the negative electrode caused by expansion and contraction did not achieve a long cycle life

Method used

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  • Negative electrode active material for lithium secondary battery and method for manufacturing same
  • Negative electrode active material for lithium secondary battery and method for manufacturing same
  • Negative electrode active material for lithium secondary battery and method for manufacturing same

Examples

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Embodiment 1

[0073] A commercially available aluminum foil with a thickness of 0.12mm made of Al with a purity of 99.9% by mass is divided into small pieces by a shredder device, and passed through a sieve with a mesh size of 0.045mm (based on JIS Z8801-1) Formed mesh screen (32) figure 2 The pulverization apparatus shown performs pulverization to produce a negative electrode active material made of powder. The particles in the obtained negative electrode active material are of a size that can pass through a sieve with a mesh size of 0.045 mm (based on JIS Z8801-1), and the specific surface area of ​​the powder based on the BET method is 0.6 m 2 / g.

[0074] Next, the negative electrode active material: 90 parts by mass, the binder formed by polyvinylidene fluoride: 5 parts by mass and the conduction aid formed by acetylene black: 5 parts by mass were mixed, and the mixture was coated on a surface with a thickness of 10 μm. on the current collector formed of copper foil. Then, using 1c...

Embodiment 2

[0076] After a commercially available aluminum foil with a thickness of 0.12mm made of Al with a purity of 99.9% by mass was divided into small pieces by a shredder, it was passed through a mesh having a mesh size of 0.045mm (based on JIS Z8801-1). (32) figure 2 The pulverization device shown performs pulverization to make a powder. The particles in the obtained powder were of a size capable of passing through a sieve with a mesh size of 0.045 mm (based on JIS Z8801-1).

[0077] Next, the particles of the powder obtained as described above were subjected to a chemical dissolution treatment for 40 minutes in 5N-HCl at a liquid temperature of 60° C. to produce a negative electrode active material. The specific surface area based on the BET method of the powder constituting the obtained negative electrode active material was 1.1 m 2 / g.

[0078] Next, the negative electrode active material: 90 parts by mass, the binder formed by polyvinylidene fluoride: 5 parts by mass and th...

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Abstract

The present invention provides a negative electrode active material for a lithium secondary battery according to which prolongation of the cycle life of a lithium secondary battery can be achieved. The negative electrode active material for a lithium secondary battery is formed from a powder which is a collection of particles formed by cutting an aluminum foil having a thickness of 0.15 mm or less. The particles have a size enabling passage through a sieve having a mesh size of 0.1 mm (according to JIS Z8801-3), and the specific surface area of the powder according to a BET method is 0.3 m2 / g or greater.

Description

technical field [0001] The present invention relates to a negative electrode active material for a lithium secondary battery and a method for producing the same, and more specifically, to a negative electrode active material for a nonaqueous electrolyte secondary battery capable of reversibly absorbing and releasing Li ions in a large amount and a method for producing the same. Here, the nonaqueous electrolyte secondary battery includes a secondary battery using a nonaqueous electrolyte obtained by dissolving an electrolyte in an organic solvent, and a secondary battery using a nonaqueous electrolyte such as a polymer electrolyte or a gel electrolyte. Background technique [0002] Lithium secondary batteries such as lithium ion batteries and lithium polymer batteries have high energy density, and are attracting attention not only as main power sources for mobile communication devices and portable electronic devices, but also as large power storage power sources or vehicle pow...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/38B22F1/05B22F1/068
CPCH01M4/04B22F9/04B22F2301/054B22F1/0011H01M2004/021B22F1/0055H01M4/38Y02E60/122B22F1/05B22F1/068Y02E60/10
Inventor 久幸晃二坂口雅司黑住忠利
Owner SHOWA DENKO KK
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