Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Negative electrode for lithium secondary battery and lithium secondary battery containing the same

A lithium secondary battery and negative electrode technology, which is applied in the structural field of current collectors and active material layers, can solve the problems of current collector fracture, current collector wrinkling, negative electrode degradation, etc., and achieve the effect of suppressing wrinkles and improving cycle characteristics

Inactive Publication Date: 2009-06-03
PANASONIC CORP
View PDF4 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, even if the columnar particles are inclined, if the particle diameter of the columnar particles is increased, the particles are connected to each other, and when the active material layer is expanded during charging, the negative electrode is greatly deformed, and wrinkles sometimes occur in the current collector, or the current collector fracture
In this case, even if the charge-discharge cycle is repeated only a small number of times, the negative electrode sometimes deteriorates

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Negative electrode for lithium secondary battery and lithium secondary battery containing the same
  • Negative electrode for lithium secondary battery and lithium secondary battery containing the same
  • Negative electrode for lithium secondary battery and lithium secondary battery containing the same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0178] A laminated lithium secondary battery as shown in FIG. 11 was fabricated.

[0179] (I) Preparation of positive electrode

[0180] Fully mix 10 g of positive electrode active material, that is, lithium cobaltate (LiCoO) with an average particle size of 10 μm. 2 ) powder, 0.3g conductive agent namely acetylene black, 0.8g binder namely polyvinylidene fluoride powder, appropriate amount of N-methylpyrrolidone (NMP), and prepare positive electrode mixture slurry.

[0181] The obtained slurry was coated on one side of a positive electrode current collector made of an aluminum foil having a thickness of 20 μm, followed by drying and rolling to form a positive electrode active material layer. Next, the obtained positive electrode sheet was cut into a predetermined shape to obtain a positive electrode. The positive electrode active material layer carried on one side of the current collector had a thickness of 70 μm and a size of 14.5 mm×14.5 mm. A positive electrode lead mad...

Embodiment 2

[0266] Next, an experiment was performed to find an appropriate size range by changing the size of the protruding region. Negative electrodes 2A to 2D were produced in the same manner as in Example 1 except that the pattern of the protruding regions provided on the current collector was changed as follows and the negative electrode active material layer was changed as follows. Batteries 2A to 2D were produced in the same manner as in Example 1 except that negative electrodes 2A to 2D were used.

[0267] (I) Negative electrode 2A

[0268] Set the shape of the cross-section of the protruding area to W a 8μm, W b A rhombus of 10 μm. along the largest diameter W a The distance L between adjacent protruding regions in the vertical direction was 18 μm. The height H of the protruding region was 6 μm. Except for this, a negative electrode current collector 2A was produced in the same manner as in Example 1.

[0269] In addition, in the negative electrodes 2B to 2D, the maximum ...

Embodiment 3

[0295] Next, an experiment was performed to find an appropriate range of the area ratio and the line segment ratio of the protruding region.

[0296]The area ratio and line segment ratio of the protruding regions were adjusted by changing the distance L between the protruding regions adjacent in the direction perpendicular to the maximum diameter Wa.

[0297] The patterns of the rhombic protruding regions provided on the current collectors were changed as follows to prepare negative electrodes 3A to 3D. Batteries 3A to 3D were produced in the same manner as in Example 1 except that negative electrodes 3A to 3D were used.

[0298] (I) negative electrode 3A

[0299] In addition to specifying the shape of the cross-section of the protruding region as W a 20μm, W b Negative electrode current collector 3A was produced in the same manner as in Example 1, except that the distance L between the protruding regions was 7 μm and the height H of the protruding regions was 3.5 μm, excep...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
roughnessaaaaaaaaaa
sizeaaaaaaaaaa
apparent porosityaaaaaaaaaa
Login to View More

Abstract

The present invention provides a negative electrode for lithium secondary batteries, which comprises a collector and a negative electrode active material layer supported on the collector. The negative electrode active material layer contains a plurality of columnar particles. The surface of the collector has recessed portions and a plurality of projected regions defined by the recessed portions. The projected regions are loaded with the columnar particles. Also disclosed is a lithium secondary battery using such a negative electrode. The negative electrode for lithium secondary batteries is particularly excellent in cycle characteristics and has a high capacity.

Description

technical field [0001] The invention relates to a lithium secondary battery, in particular to the structure of a negative electrode current collector and an active material layer. Background technique [0002] In recent years, with the development of portable devices such as personal computers and mobile phones, the demand for batteries serving as power sources thereof has increased. Batteries used for the above applications require high energy density and excellent cycle characteristics while being used at room temperature. [0003] In response to the above-mentioned requirements, high-capacity positive electrode active materials and negative electrode active materials have been newly developed. Among them, a battery using a simple substance of silicon (Si) or tin (Sn), an oxide thereof, or an alloy thereof, which can obtain a very high capacity, as a negative electrode active material is expected to be promising. [0004] On the other hand, for example, in the case of a ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/02H01M4/38H01M4/48H01M4/70H01M4/134H01M10/052
CPCY02E60/122H01M4/134H01M4/661H01M10/052H01M4/70Y02E60/10H01M4/02H01M4/38H01M4/58H01M10/05
Inventor 宇贺治正弥长谷川正树山本泰右大原敬介古结康隆西村卓宽
Owner PANASONIC CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com