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

Secondary battery and terminal

A secondary battery and terminal technology, applied in secondary batteries, secondary battery repair/maintenance, battery electrodes, etc., can solve the problems of high risk of battery thermal runaway, thermal runaway chain reaction, shrinkage and melting of diaphragm, etc., to reduce contact The probability of short circuit occurrence, the effect of alleviating the chain reaction of thermal runaway, and improving safety performance

Pending Publication Date: 2022-01-14
HUAWEI TECH CO LTD
View PDF7 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Among them, since the short-circuit resistance of the positive electrode current collector (aluminum foil) and the negative electrode active material layer are relatively close to the internal resistance of the battery, the short-circuit point generates the largest heat power at this time, and the temperature rises rapidly. The temperature rise causes SEI to decompose and the diaphragm shrinks and melts, resulting in battery Highest risk of thermal runaway
At the same time, since secondary batteries are usually composed of battery cell components (positive electrode current collector-positive electrode active material layer-separator-negative electrode active material layer-negative electrode current collector) by stacking or winding, in the process of foreign matter penetrating until the battery is pierced In the process, all kinds of debris generated by destruction are often in random contact, and internal short circuits are more likely to occur. At the same time, the heat release of internal short circuits can easily trigger thermal runaway chain reactions.

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
  • Secondary battery and terminal
  • Secondary battery and terminal
  • Secondary battery and terminal

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] Lithium cobaltate is used as the positive electrode active material, aluminum foil is used as the positive electrode current collector, and the positive electrode active material layer is uniformly coated on the surface of the positive electrode current collector. The composition of the positive electrode active material layer is 97.0wt% lithium cobaltate, 1.6wt% polyvinylidene fluoride and 1.4wt% conductive carbon black, dried at 80°C, after cold pressing, cutting, slitting, and vacuum drying, the positive electrode sheet was obtained;

[0048] Graphite is used as the negative electrode active material, copper foil is used as the negative electrode current collector, and the negative electrode active material layer is evenly coated on the surface of the negative electrode current collector. The composition of the negative electrode active material layer is 97.4wt% graphite, 1.4wt% styrene-butadiene rubber and 1.2wt% Sodium methyl cellulose, dried at 80°C, cold-pressed, ...

Embodiment 2-19

[0051] The preparation method of the secondary battery is the same as in Example 1, except that the elongation of the separator, the ratio of the elongation of the separator to the thickness of the active material layer, and the ratio of the elongation of the separator to the elongation of the current collector are different from that of Example 1, specifically See Table 1.

Embodiment 20

[0059] The preparation method is the same as in Example 1, except that the thickness of the positive electrode active material layer in Example 20 is 36 μm, the thickness of the negative electrode active material layer is 48 μm, and the ratio of the elongation of the separator to the thickness of the active material layer is 5.0% / μm and 3.75% / μm.

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
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
thicknessaaaaaaaaaa
Login to View More

Abstract

The invention provides a secondary battery. The secondary battery comprises at least one battery unit assembly, each battery unit assembly comprises a positive pole piece, a negative pole piece and a diaphragm arranged between the positive pole piece and the negative pole piece, and each of the positive pole piece and the negative pole piece comprises a current collector and an active material layer arranged on the current collector; and the elongation rate of the diaphragm is greater than 100%, the elongation rate of the diaphragm comprises the elongation rate along the length direction and / or the elongation rate along the width direction, the ratio of the elongation rate of the diaphragm to the thickness of the active material layer of the positive pole piece and / or the negative pole piece is 3.0-8. 0 % / [mu]m, and the ratio of the elongation of the diaphragm to the elongation of the current collector of the positive pole piece and / or the negative pole piece is greater than or equal to 60. The secondary battery provided by the embodiment of the invention has high safety performance on the basis of considering high energy density. The embodiment of the invention also provides a terminal comprising the secondary battery.

Description

technical field [0001] The present application relates to the technical field of secondary batteries, in particular to a secondary battery and a terminal. Background technique [0002] With the development of the Internet and the popularization of portable mobile electronic devices, people have higher and higher requirements for the battery life and fast charging capacity of lithium secondary batteries, but there are also more and more battery thermal runaway accidents. A large number of studies and analyzes have found that the internal short circuit caused by the mechanical abuse of the secondary battery (such as nailing, bending, foreign matter extrusion, etc.) is one of the main reasons for its thermal runaway. When the secondary battery is damaged by mechanical external force, such as needle-shaped conductors or other foreign matter pierced, the current collector and active material layer are destroyed, debris is generated, and direct contact short circuit occurs. At the...

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): H01M50/40H01M4/13H01M4/66H01M10/052H01M10/054H01M10/058H01M10/42
CPCH01M4/667H01M4/661H01M10/058H01M4/13H01M10/052H01M10/054H01M10/4235H01M50/40H01M10/42H01M4/66H01M50/494H01M50/46Y02E60/10Y02P70/50H01M50/417H01M10/0525H01M50/491H01M50/409H01M50/489H01M10/0585H01M50/451H01M50/426H01M2004/021H01M4/5825H01M50/423H01M50/463H01M4/624H01M50/414H01M10/04
Inventor 李政杰邓耀明张新枝高云雷阳东方洪达谢封超
Owner HUAWEI TECH CO LTD
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