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

A positive pole piece, its preparation method and electrochemical device

A positive pole piece, electrochemical technology, applied in the field of energy storage, can solve the problems of battery life damage, easy peeling of the coating layer, and decline in the ability of the pole piece to conduct ions

Active Publication Date: 2022-01-14
CONTEMPORARY AMPEREX TECH CO
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, for conventional positive electrode active materials, under high charge and discharge voltage, the positive electrode active material delithiates excessively, and its crystal structure is prone to structural changes or even collapse; under high voltage, organic solvents and additives in the electrolyte, due to Its chemical stability is poor and it is easy to decompose, especially when the lithium transition metal oxide contains strong oxidizing nickel ions, it is easy to have side reactions with the electrolyte, resulting in serious gas production problems, causing battery capacity attenuation and cycle performance. Poor, high-temperature storage performance is severely deteriorated, which not only brings irreversible damage to battery life, but also brings serious safety hazards
To increase the gram capacity is usually to use a lithium transition metal oxide with a higher theoretical capacity and increase its compaction density. However, as the compaction density of the pole piece increases, the porosity decreases, and the ability of the pole piece to absorb and store electrolyte It also weakens, the ion-conducting ability of the pole piece decreases, and the overall resistance of the battery cell increases, which leads to poor cycle performance of the battery
[0004] In order to solve the above problems, at present, the positive active material particles are mainly coated and modified to stabilize the crystal structure of the particles and avoid the side reaction of the electrolyte on the surface of the particles. Difficulties such as agglomeration and complex coating process, and because the outer surface of the particles is covered with chemically inert inorganic substances, the conductivity between the active material particles in the pole piece is poor, the DCR of the battery is high, and the protection of the electrolyte by the pole piece The problem of low liquid rate is not improved obviously

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
  • A positive pole piece, its preparation method and electrochemical device
  • A positive pole piece, its preparation method and electrochemical device
  • A positive pole piece, its preparation method and electrochemical device

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0048] The method for preparing a positive electrode sheet according to the second aspect of the embodiment of the present application at least includes the following steps:

[0049] Prepare a mixed slurry containing positive electrode active material, binder and conductive agent;

[0050] coating the slurry on at least one surface of the positive electrode collector, and drying to form a positive electrode membrane;

[0051] On the surface of at least one positive electrode diaphragm away from the positive electrode current collector, an inorganic layer with a thickness of 20nm to 2000nm is prepared by vapor deposition; the inorganic layer is a porous dielectric layer without a binder, and the porosity of the inorganic layer is 10% to 60%.

[0052]Further optionally, vapor deposition methods include atomic layer deposition (Atomic Layer Deposition, ALD), chemical vapor deposition (Chemical Vapor Deposition, CVD), physical vapor deposition (Physical VaporDeposition, PVD) and ...

Embodiment

[0079] The lithium ion secondary battery is prepared by the above method, and inorganic layers with different thicknesses and porosities are prepared on the positive electrode diaphragm of the positive electrode sheet by the above gas phase deposition method.

[0080] The specific process parameters are: the target material is metal aluminum, and the vacuum degree of the deposition chamber is less than 1×10 -3 Pa, when the target material is Al metal, the heating evaporation current is 190A, the oxygen flow rate is 300sccm, the plasma power is about 300W to activate the reaction gas, and the process time is 5min.

[0081] The specific parameters of the prepared positive electrode sheet are shown in Table 1.

[0082] Among them, alumina powder is mixed with polyvinylidene fluoride binder (binder content 50%), and coated on the surface of the positive electrode diaphragm. Due to process limitations, the minimum coating thickness can only be 2000nm, that is, the positive electrod...

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
pore sizeaaaaaaaaaa
thicknessaaaaaaaaaa
Login to View More

Abstract

The present application relates to the field of energy storage, in particular, to a positive pole piece, a preparation method thereof and an electrochemical device. The present application relates to a positive electrode sheet, including a positive electrode collector and a positive electrode membrane containing a positive electrode active material arranged on at least one surface of the positive electrode collector, and at least one positive electrode membrane is arranged on the surface of the side away from the positive electrode collector There is an inorganic layer with a thickness of 20nm-2000nm, the inorganic layer is a porous dielectric layer without binder, and the porosity of the inorganic layer is 10%-60%. In the present application, the positive electrode membrane significantly improves the cycle performance, high-temperature storage performance and safety of the electrochemical device.

Description

technical field [0001] The present application relates to the field of energy storage, in particular, to a positive pole piece, a preparation method thereof and an electrochemical device. Background technique [0002] Due to its high working voltage, high energy density, no memory effect, and environmental protection, lithium-ion batteries have become the main power source of various consumer electronics products, power products, and energy storage, and are used in all aspects of people's lives. In recent years, as the market, especially the power battery market, has higher and higher requirements for battery energy density and charging efficiency, this makes the demand for cathode materials with higher compaction density and higher capacity stronger. [0003] In the secondary battery, in order to meet the demand for large capacity of the battery, it is mainly achieved by increasing the charging cut-off voltage and increasing the gram capacity. However, for conventional pos...

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 Patents(China)
IPC IPC(8): H01M4/131H01M4/136H01M4/1391H01M4/1397H01M4/62H01M10/0525
CPCH01M4/628H01M4/131H01M4/136H01M4/1391H01M4/1397H01M10/0525H01M4/0421H01M4/0423H01M4/0426H01M4/0428H01M4/505H01M4/525H01M4/5825H01M10/052H01M2004/021Y02E60/10H01M50/46H01M2004/028
Inventor 王铈汶黄起森黄华锋梁成都
Owner CONTEMPORARY AMPEREX TECH CO
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