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Diaphragm, battery core and winding method thereof

A diaphragm and cell technology, applied in the manufacture of circuits, electrical components, secondary batteries, etc., can solve problems such as short circuit or micro-short circuit, diaphragm puncture, powder drop, etc., to improve life, not easy to break, reduce powder drop The effect of the probability of

Active Publication Date: 2011-05-18
SHENZHEN EPT BATTERY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the thickness of the diaphragm is contradictory to its mechanical strength and liquid retention capacity. Especially for high-capacity batteries, due to the occurrence of certain micro-cracks in the electrode sheet during the winding process, certain powder shedding or certain burrs will occur. The separator is easy to be punctured at the front end of the winding or all the microcracks after the electrode sheet is wound, or to form a short circuit or a micro short circuit due to falling powder

Method used

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  • Diaphragm, battery core and winding method thereof
  • Diaphragm, battery core and winding method thereof
  • Diaphragm, battery core and winding method thereof

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Embodiment approach 1

[0039] The diaphragm 300 adopts a multi-stage connection method, and the diaphragm 300 is all treated with polypropylene sulfonation. The thickness of the innermost diaphragm 301 of the cell is 0.18mm, the thickness of the second diaphragm 300 is 0.12mm, the thickness of the third diaphragm 300 is 0.11mm, and the thickness of the outermost diaphragm 300 is 0.09mm. figure 1 The sequence shown uses thermocompression bonding.

Embodiment approach 2

[0041] The diaphragm 300 adopts a multi-stage connection method, and the diaphragm 300 is all treated with polypropylene sulfonation. The thickness of the innermost diaphragm 301 of the cell is 0.18mm, the thickness of the second diaphragm 300 is 0.15mm, the thickness of the third diaphragm 300 is 0.11mm, and the thickness of the outermost diaphragm 300 is 0.09mm. figure 1 The sequence shown uses thermocompression bonding.

Embodiment approach 3

[0043] The diaphragm 300 is connected in multiple sections. The innermost diaphragm 301 of the cell uses a polypropylene fluorinated diaphragm with a thickness of 0.18mm, the second circle uses a polypropylene sulfonated diaphragm with a thickness of 0.12mm, and the third circle uses a polypropylene sulfonated diaphragm with a thickness of 0.11mm. The outer ring uses a polypropylene sulfonated diaphragm with a thickness of 0.09mm, and each segment of the diaphragm is pressed figure 1 The sequence shown uses thermocompression bonding.

[0044] The following comparative examples are embodiments of the prior art, compared to illustrate the specific advantages of the embodiments of the present invention:

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Abstract

The invention relates to a diaphragm, a battery core and a winding method thereof. The diaphragm has at least two different thicknesses along the unfolding direction; and when the diaphragm is used for winding a battery core, the thickness of the diaphragm wound in the inner circle is not smaller than that of the diaphragm wound in the outer circle. Compared with the prior art, the diaphragm provided by the invention has the advantage of being capable of reducing the frequency of short circuits or micro short circuits and accommodating more electrolyte so as to improve the capacity and the service life of the battery core under the premise that the requirement for sufficient mechanical strength is met.

Description

technical field [0001] The invention relates to a diaphragm, an electric core and a winding method for the electric core. Background technique [0002] Now, the diaphragm of the wound battery cell is placed between the positive electrode and the negative electrode. Its main function is to prevent the active material of the positive electrode sheet and the negative electrode sheet from contacting, thereby causing a short circuit in the cell. The diaphragm occupies a very important position in the battery, which directly affects the short circuit, low voltage performance, life and self-discharge performance of the battery. [0003] Generally speaking, good chemical stability and certain mechanical strength are required for wound cell separators. However, the thickness of the diaphragm is contradictory to its mechanical strength and liquid retention capacity. Especially for high-capacity batteries, due to the occurrence of certain micro-cracks in the electrode sheet during the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M2/18H01M2/16H01M10/04
CPCY02E60/12Y02E60/10Y02P70/50
Inventor 王守军彭东方莫元妙王卫东刘新华
Owner SHENZHEN EPT BATTERY