Lithium ion battery diaphragm, preparation method thereof and lithium ion battery

A technology of lithium-ion batteries and diaphragms, which is applied in secondary batteries, battery pack components, circuits, etc., can solve the problems of high impedance of ceramic coatings and inability to effectively absorb metal ions, achieve low impedance, improve battery performance, Avoid the effect of precipitation

Pending Publication Date: 2021-06-04
EVERGRANDE NEW ENERGY TECH SHENZHEN CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a lithium-ion battery diaphragm and its preparation method and lithium-ion battery, aiming to solve the technical problem that the ceramic coating has high impedance and cannot effectively absorb metal ions dissolved from the positive electrode

Method used

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  • Lithium ion battery diaphragm, preparation method thereof and lithium ion battery
  • Lithium ion battery diaphragm, preparation method thereof and lithium ion battery
  • Lithium ion battery diaphragm, preparation method thereof and lithium ion battery

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preparation example Construction

[0039] On the other hand, the embodiment of the present invention also provides a preparation method of lithium-ion battery diaphragm, comprising the following steps:

[0040] S01: Prepare a ceramic slurry containing the first type of particles and the second type of particles; wherein, the first type of particles contain ceramic particles and polymer lithium salt, and the ceramic particles and polymer lithium salt are connected by chemical groups;

[0041] S02: coating the ceramic slurry on at least one surface of the base film, and then performing drying treatment to obtain a ceramic coating.

[0042] In the preparation method of lithium-ion battery diaphragm provided in the embodiment of the present invention, a ceramic coating containing the first type of particles and the second type of particles is formed on the surface of the base film, and the first type of particles modified with polymer lithium salt and the The combination of unmodified second-type particles can impr...

Embodiment 1

[0053] A preparation method for a lithium ion battery, comprising the steps of:

[0054] (1) Preparation of the positive electrode: disperse and dissolve the lithium iron phosphate positive electrode material, 1% SP, 1% CNT, and 3% PVDF binder in N-methylpyrrolidone, then coat it on a 12um aluminum foil, and dry it into the positive pole.

[0055] (2) Preparation of negative electrode: disperse graphite, 2% SBR, 1.5% CMC, and 1% SP in water, then coat on 8um copper foil, and dry to make negative electrode.

[0056] (3) Preparation of diaphragm:

[0057] Put the alumina ceramic powder with an average particle size of about 500nm into methyl ethyl ketone to disperse by ball milling, then add 3% KH550 (γ-aminopropyltriethoxysilane), reflux reaction, then cool, filter and wash to obtain Surface NH 2 - Chemically modified alumina particles.

[0058] Put the above-mentioned modified alumina particles and 3% acryloyl chloride into the dichloromethane solution to disperse and reac...

Embodiment 2

[0062] A preparation method of a lithium-ion battery, the preparation method of the separator is different, and the others are the same as in Example 1.

[0063] The membrane preparation method of the present embodiment is as follows:

[0064] Put the alumina ceramic powder with an average particle size of about 500nm into methyl ethyl ketone for ball mill dispersion, then add 3% KH550, reflux reaction, then cool, filter, and wash to obtain surface NH 2 - Chemically modified alumina particles.

[0065] Put the above-mentioned modified alumina particles and 3% p-vinylbenzenesulfonyl chloride into a dichloromethane solution for dispersion reaction, then disperse them in water with 30% lithium p-styrenesulfonate, add 0.3% ammonium persulfate / sodium bisulfate initiator, heated at 50° C. for 4 hours for polymerization reaction, and then centrifuged to obtain alumina particles grafted with polymer lithium salt (mass fraction of polystyrene sulfonate lithium 15%) on the surface.

...

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Abstract

The invention belongs to the technical field of lithium ion battery materials, and particularly relates to a lithium ion battery diaphragm, a preparation method thereof and a lithium ion battery. The lithium ion battery diaphragm comprises a base membrane and a ceramic coating arranged on at least one surface of the base membrane, the ceramic coating comprises a first type of particles and a second type of particles, the first type of particles comprise ceramic particles and polymer lithium salt, and the ceramic particles and the polymer lithium salt are connected through chemical groups. According to the ceramic coating on the surface of the lithium ion battery diaphragm, the first type of particles modified by the polymer lithium salt and the second type of particles which are not modified are matched for use, so that the diaphragm has low impedance and has the effect of adsorbing metal ions dissolved out of a positive electrode, the metal ions of the positive electrode are prevented from being separated out at a negative electrode, and the battery performance is improved.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery materials, and in particular relates to a lithium-ion battery diaphragm, a preparation method thereof, and a lithium-ion battery. Background technique [0002] Lithium-ion batteries have many advantages such as high voltage, high specific energy, high specific power, wide operating temperature range, no memory effect, and long storage time. They have been widely used in many fields such as mobile phones, notebook computers, power tools, and automobiles. With the continuous increase of energy density, lithium-ion batteries are more and more prone to thermal runaway, and their safety risks are also increasing. As one of the four main materials of the battery cell, the diaphragm plays the role of isolating the positive and negative electrodes and conducting lithium ions, and plays a vital role in the safety and output characteristics of the battery cell. [0003] Currently widely used se...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M50/446H01M50/434H01M50/451H01M50/403H01M10/0525
CPCH01M10/0525Y02E60/10
Inventor 鲁丹钟世昌赵文文张勍黄继春
Owner EVERGRANDE NEW ENERGY TECH SHENZHEN CO LTD
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