Polymer lithium ion secondary battery and isolating membrane thereof

A secondary battery, lithium ion technology, applied in secondary batteries, battery electrodes, battery pack components, etc., can solve the problem of affecting the cycle performance of lithium ion secondary batteries, increasing the irreversible capacity loss of battery cycles, Battery combustion and other problems, to avoid irreversible capacity loss or failure to work properly, good mechanical tensile strength, good cycle performance and safety performance

Active Publication Date: 2010-10-27
DONGGUAN NEWPOWER ELECTRIC SCI & TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, lithium-ion secondary batteries generally have serious safety concerns: flammable liquid organic solvents are prone to leakage and may cause lithium-ion secondary batteries to burn or explode
[0005] Although the above-mentioned existing gel polymer electrolyte has good electrochemical properties in simulated batteries or button batteries, when it is applied to the production of industrialized lithium-ion secondary batteries, the impure substances that may be mixed in the polymer will be in the The irreversible oxidative decomposition of the cathode of the battery increases the irreversible capacity loss of the battery cycle, and the resulting battery capacity attenuation is particularly serious, which seriously affects the cycle performance of the lithium-ion secondary battery.

Method used

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  • Polymer lithium ion secondary battery and isolating membrane thereof
  • Polymer lithium ion secondary battery and isolating membrane thereof
  • Polymer lithium ion secondary battery and isolating membrane thereof

Examples

Experimental program
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preparation example Construction

[0025] Preparation of isolation membrane: Take the untreated porous substrate multilayer composite polyethylene and polypropylene microporous membrane (isolation membrane before treatment) as a control.

[0026] Preparation of polymer lithium-ion secondary battery: the cathode sheet containing lithium cobalt oxide as the cathode active material, the above separator, and the anode sheet containing artificial graphite as the anode active material are wound into a battery core, and the separator is separated from the adjacent cathode, Between the anode sheets, the cathode is led out by aluminum tab spot welding, and the anode is drawn out by nickel tab spot welding; then, the battery cell is mixed with lithium salt lithium hexafluorophosphate and non-aqueous solvent ethylene carbonate, dimethyl carbonate, ethyl methyl carbonate The composed electrolyte is packaged in a packaging case to make a polymer lithium ion secondary battery. Example 1

Embodiment 1

[0027] Preparation of the isolation film: Dissolve the polymer poly(methyl methacrylate-vinyl acetate) in acetone solvent at 25 °C to obtain a solution with a solid content of 2%; then, the solution is processed by printing on the porous The substrate is multilayered with polyethylene and polypropylene microporous membranes on one surface to obtain a single-sided treated polymer barrier membrane.

[0028] Preparation of polymer lithium ion secondary battery: the cathode sheet containing the cathode active material lithium cobaltate, the single-side treated polymer separator prepared according to the above method, and the anode sheet containing the anode active material artificial graphite are wound into an electric battery. The core, the separator is spaced between the adjacent cathode and anode sheets, the single-sided processed polymer separator is in direct contact with the anode sheet, the cathode is led out by spot welding of aluminum tabs, and the anode is drawn out by sp...

Embodiment 2

[0032] Preparation of isolation membrane: Dissolve the polymer poly(methyl methacrylate-acrylonitrile) in acetone solvent at 35 °C to obtain a solution with a solid content of 3%; then, the solution is treated by coating method on the porous On one surface of the substrate a polypropylene microporous membrane, a single-side treated polymer barrier membrane is obtained.

[0033] Preparation of a polymer lithium ion secondary battery: the cathode sheet containing the cathode active material nickel cobalt lithium manganese oxide, the single-sided treated polymer separator prepared according to the above method, and the anode containing the anode active material mesophase carbon microspheres The sheet is wound into a cell, the separator is spaced between the adjacent cathode and anode sheets, the single-sided treated polymer separator is in direct contact with the anode sheet, the cathode is led out by spot welding of aluminum tabs, and the anode is led out by nickel tabs. Then, t...

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Abstract

The invention discloses an isolating membrane of lithium ion secondary battery, comprising a porous substrate and a polymer coating distributed only on a surface of the porous substrate which faces an anode of the lithium ion secondary battery, wherein the polymer in the polymer coating is selected from poly(methyl methacrylate-acrylonitrile), poly(methyl methacrylate-vinyl acetate), poly(methyl methacrylate-acrylonitrile-vinyl acetate), poly(n-butyl methacrylate-styrene), or blends of the polymers. The polymer unit in the polymer coating of the isolating membrane of the lithium ion secondary battery contains carbonyl, wherein very strong effect exists between the carbonyl and oxygen in carbonic acid ester type organic solvent so as to have fine solution suction ability and good interface stability of lithium electrode or anode; the membrane has strong adhesive property and film formation, and can provide fine mechanical tensile strength; and the membrane has fine cycle performance and safety performance. The invention further discloses a polymer lithium ion secondary battery using the membrane.

Description

technical field [0001] The invention relates to a lithium ion secondary battery, in particular to a polymer lithium ion secondary battery with good safety performance and its isolation film. Background technique [0002] Since its appearance in the 1990s, lithium-ion secondary batteries have been widely used for video cameras, notebook computers, portable DVDs, digital cameras, etc. Various mobile devices and devices provide energy, known as "green high-energy and environmentally friendly batteries". [0003] However, lithium-ion secondary batteries usually have serious safety issues: flammable liquid organic solvents are easy to leak and may cause lithium-ion secondary batteries to burn or explode. To improve the safety performance of lithium-ion secondary batteries, solid electrolytes (SPEs) that do not contain any solvent molecules can be used. However, the ionic conductivity of SPE at room temperature is only 1×10 -5 S cm -1 , about three orders of magnitude lower...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/16H01M10/0525H01M4/136H01M4/62H01M50/414H01M50/417H01M50/449
CPCY02E60/12Y02E60/122Y02E60/10
Inventor 付成华廖友好邓勇强李伟善许瑞
Owner DONGGUAN NEWPOWER ELECTRIC SCI & TECH
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