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A dry-process uniaxially stretched membrane with uniform pore formation and preparation method thereof

A unidirectional stretching and uniform technology, applied in the direction of structural parts, electrical components, battery pack parts, etc., can solve problems such as unevenness, affecting the cost of diaphragm manufacturing, diaphragm hole consistency, long heat treatment time, etc., to achieve production efficiency Improvement, good annealing uniformity, and good hole-forming uniformity

Active Publication Date: 2019-09-17
SHENZHEN SENIOR TECH MATERIAL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the heat treatment process of the diaphragm in China is to rewind the cast film and then perform the oven heat treatment. Not only the heat treatment time is long but also very uneven, which seriously affects the manufacturing cost of the diaphragm and the consistency of the diaphragm hole formation.

Method used

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  • A dry-process uniaxially stretched membrane with uniform pore formation and preparation method thereof
  • A dry-process uniaxially stretched membrane with uniform pore formation and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] a. Cast sheet: Plasticize polyolefin particles through an extruder to form a polyolefin melt, then extrude from a die head at low temperature, cast a sheet with a cooling roller, and obtain a sheet-shaped polyolefin-based film after shaping and annealing by a shaping roller;

[0036] b. Uniaxial stretching: the annealed polyolefin base film is stretched, shaped at high temperature, and cooled to obtain a dry-process uniaxially stretched diaphragm with uniform pores;

[0037] In step a, the working temperature of the extruder is 170°C, the set temperature of the die head is 180°C, the temperature of the cooling roll is set at 50°C, and the temperature of the shaping roll is 100°C;

[0038] In step b, the stretching speed is 1.0 m / min, the magnification is 1.5 times, and the temperature is 120° C.; the high-temperature setting temperature is 150° C., and the high-temperature setting time is 1 min.

Embodiment 2

[0040] a. Cast sheet: plasticize polyolefin particles through an extruder to form a polyolefin melt, then extrude from a die head at low temperature, cast a sheet with a cooling roll, and obtain a sheet-shaped polyolefin-based film after being shaped and annealed by a shaping roller;

[0041] b. Uniaxial stretching: the annealed polyolefin-based film is stretched, shaped at high temperature, and cooled to obtain a dry-process uniaxially stretched diaphragm with uniform pores;

[0042] In the step a, the working temperature of the extruder is 250°C, the set temperature of the die head is 240°C, the temperature of the cooling roll is set at 120°C, and the temperature of the shaping roll is 160°C;

[0043] In step b, the stretching speed is 8.0 m / min, the magnification is 3.0 times, and the temperature is 160° C.; the high-temperature setting temperature is 160° C., and the high-temperature setting time is 4 minutes.

Embodiment 3

[0045] a. Cast sheet: plasticize polyolefin particles through an extruder to form a polyolefin melt, then extrude from a die head at low temperature, cast a sheet with a cooling roll, and obtain a sheet-shaped polyolefin-based film after being shaped and annealed by a shaping roller;

[0046] b. Uniaxial stretching: the annealed polyolefin-based film is stretched, shaped at high temperature, and cooled to obtain a dry-process uniaxially stretched diaphragm with uniform pores;

[0047] In step a, the working temperature of the extruder is 190°C, the set temperature of the die head is 185°C, the temperature of the cooling roll is set at 60°C, and the temperature of the shaping roll is 130°C;

[0048] In step b, the stretching speed is 3.0 m / min, the magnification is 1.8 times, and the temperature is 130° C.; the high-temperature setting temperature is 160° C., and the high-temperature setting time is 2 minutes.

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Abstract

The consistency of the diaphragm mainly includes the consistency of the thickness of the diaphragm and the consistency of the holes. However, the current domestic heat treatment process of the diaphragm is to wind the cast film and then perform the oven-type heat treatment. Not only the heat treatment time is long but also very uneven, which seriously affects the Diaphragm manufacturing cost and consistency of diaphragm pore formation. Therefore, it is of great significance to improve the consistency of the heat treatment of the separator and then improve the uniformity of the pore formation of the separator. The invention provides a dry-process uniaxially stretched membrane with uniform pores and a preparation method thereof. The production equipment / process technology using this method is simple and mature. , can be efficiently and continuously mass-produced without the need for a separate heat treatment oven for long-term annealing treatment. The cost of the prepared dry-process uniaxially stretched membranes of various specifications is relatively low, and the air permeability is extremely poor ≤ 70s.

Description

technical field [0001] The invention belongs to the field of preparation of lithium battery dry-process uniaxially stretched diaphragms, in particular to a dry-process uniaxially stretched diaphragm with uniform pore formation and a preparation method thereof. Background technique [0002] In the structure of lithium batteries, the diaphragm is one of the key inner components, which determines the interface structure and internal resistance of the battery. The difference in its performance directly affects the electrochemical performance and consistency of performance of lithium-ion batteries. A separator with good consistency can improve the consistency of the battery, which is of great significance for prolonging the service life of the battery and improving the safety performance of the battery. [0003] The consistency of the diaphragm mainly includes the consistency of the thickness of the diaphragm and the consistency of the pores. At present, the heat treatment proce...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M2/14H01M2/16H01M10/0525H01M50/403H01M50/417H01M50/491
CPCH01M10/0525H01M50/403H01M50/411H01M50/44Y02E60/10
Inventor 黄恩德李雷陈良
Owner SHENZHEN SENIOR TECH MATERIAL