Preparation method for modified diaphragm for lithium battery

A battery diaphragm and lithium battery technology, which is applied in the field of preparation of modified diaphragms for lithium batteries, can solve the problems of not significantly improving ion selectivity, increasing the thickness of polyolefin diaphragms, and affecting the performance of lithium batteries Shuttle effect, simple preparation process, and the effect of suppressing capacity attenuation

Active Publication Date: 2017-06-13
SUN YAT SEN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Although these methods can effectively improve the wettability, liquid retention and heat resistance of commercial polyolefin separators, the effect after modification is still not good, for example, the ion selective passability cannot be sig

Method used

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  • Preparation method for modified diaphragm for lithium battery
  • Preparation method for modified diaphragm for lithium battery
  • Preparation method for modified diaphragm for lithium battery

Examples

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Effect test

Embodiment 1

[0033] Positive electrode preparation process: The mass ratio of the slurry is mixed according to the mass ratio of sulfur: acetylene black: polytetrafluoroethylene = 90:5:5, and a 1×1 cm positive electrode is made on an aluminum sheet, and the prepared positive electrode is placed in a certain temperature for vacuum drying Dry at constant temperature in the box for more than 24 hours, and metal lithium is the negative electrode.

[0034] The preparation process of the modified diaphragm for lithium-sulfur batteries: the polyolefin diaphragm is ultrasonically cleaned for a certain period of time using acetone as the solvent, and then placed in a vacuum drying oven at a certain temperature to dry at a constant temperature for more than 24 hours, and the cleaned polyolefin diaphragm is single-sided Corona treatment (Corona Treating), the treatment time is 40 seconds, and the treated diaphragm is exposed to the air for 20 minutes.

[0035] Immerse the treated polyolefin separator...

Embodiment 2

[0037] The operation is the same as in Example 1, except that the cleaned polyolefin membrane is subjected to single-side plasma processing (Plasma Processing).

Embodiment 3

[0039] The operation was the same as in Example 1, except that the polyolefin separator was subjected to single-side corona treatment (Corona Treating), the treatment time was 80 seconds, and the treated separator was exposed to air for 20 minutes. A lithium-sulfur battery is assembled according to the positive electrode / separator / negative electrode.

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Abstract

The invention discloses a preparation method for a modified diaphragm for a lithium battery. The preparation method comprises the following steps of S1: performing corona treating or plasma processing on a battery diaphragm; and S2, adding the battery diaphragm processed in the step S1 into a negative ion type polymer solution to be modified to obtain the modified diaphragm for the lithium battery. The modified diaphragm prepared by the invention can effectively suppress pass of negative ions and improve mobility number of positive ions; and particularly in a lithium-sulfur battery, the modified diaphragm can effectively suppress a "flying shuttle effect" generated by the lithium-sulfur battery in a cyclic process, and can suppress capacity attenuation of the lithium-sulfur battery. The modified diaphragm provided by the invention has the advantages of high ionic selectivity, simple preparation process and low economic cost, so that an effective improvement method for development of a high-performance battery (such as a power lithium battery, a lithium-sulfur battery, a lithium cobalt oxide battery, a lithium manganate battery, a lithium phosphate battery and the like) can be provided.

Description

technical field [0001] The invention belongs to the technical field of battery separators, and more specifically relates to a preparation method of a modified separator for lithium batteries. Background technique [0002] In the structure of commercial lithium batteries, the separator is a very important part. In the battery, it mainly plays the role of isolating the positive and negative electrodes, passing lithium ions, and blocking electrons. Therefore, the charge and discharge capacity, cycle life, and safety performance of lithium batteries are all related to Diaphragms are closely related. [0003] The current commercial separators are mainly polyolefin separators, which use polyethylene (PE) and polypropylene (PP) as the main raw materials, and are produced by dry or wet processes. Polyolefin separators are roughly divided into single-layer polyethylene (PE) Diaphragm, single-layer polypropylene (PP) diaphragm, three-layer PP / PE / PP composite diaphragm. Both polyethy...

Claims

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Application Information

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IPC IPC(8): H01M2/14H01M2/16H01M50/403H01M50/411
CPCH01M50/403H01M50/411Y02E60/10
Inventor 黄逸夫王贤宏阮文红章明秋容敏智
Owner SUN YAT SEN UNIV
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