Polyolefin battery diaphragm and preparation method for the same

A battery membrane and polyolefin technology, which is applied to fuel cells, battery pack components, fuel cell components, etc., can solve the problems of complex equipment investment, low puncture strength, and difficult operation, and achieve simple stretching operation. , uniform mechanical strength, good ventilation effect

Inactive Publication Date: 2012-01-18
XINXIANG ZHONGKE SCI&TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to only uniaxial stretching, the separator is only strong in one direction, and the high porosity makes the piercing strength too low
[0007] In the Japanese patent JP-11-369289, the thick film is biaxially stretched at the same ratio by m

Method used

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  • Polyolefin battery diaphragm and preparation method for the same

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preparation example Construction

[0029] A preparation method of a polyolefin battery diaphragm, the preparation method consists of the following steps:

[0030] 1) Melt polyolefin resin, additives and solvents at a temperature of 150-280°C to form a uniform melt, wherein the weight percentage of each component is:

[0031] Polyolefin resin 15-40%,

[0032] Additive 1~10%,

[0033] The balance is solvent;

[0034] 2) extruding the molten liquid obtained in the step 1 through a die head at a temperature of 150-280° C., cooling it on a cooling roll and casting it into a thick sheet, and the cooling temperature is -5-30° C.;

[0035] 3) The slab obtained in step 2 is first stretched longitudinally, the stretching temperature is 50°C-110°C, and the longitudinal stretching ratio is 2-7 times; then the first transverse stretching is carried out, and the stretching temperature is 90°C ~150℃, the stretching ratio of the first transverse stretching is 3~9 times;

[0036] 4) extracting and removing the solvent from ...

Embodiment 1

[0046] 18% (accounting for the percentage of total feeding weight) of high-density polyethylene (HDPE, viscosity-average molecular weight 2.5 * 10 5 , melting point is 130°C), 1% (percentage of total feed weight) of antioxidant 1010 and 1% (percentage of total feed weight) of antistatic agent 600. Mix dryly in the mixer, join in twin-screw extruder (diameter 58mm, L / D=52, strong mixing type), then use metering pump, add 80% (accounting for total feeding weight) percentage) of liquid paraffin (dynamic viscosity 90cst / 40°C), melting and mixing the resin at 150°C and 156 rpm. The mixed resin solution was extruded through a T-die, and the cast sheet was cooled on a cooling roll with a surface temperature of 20° C. to obtain a thick sheet with a thickness of 0.13 mm.

[0047] The slab is stretched longitudinally and transversely in sequence, wherein the stretching ratio is vertical×horizontal=2×3, the longitudinal stretching temperature is 100°C, and the transverse stretching temp...

Embodiment 2

[0049] 15% (accounting for the percentage of total feeding weight) of high-density polyethylene (HDPE, viscosity-average molecular weight 2.5 * 10 5 , melting point is 130 ℃), 5% (accounting for the percentage of total feeding weight) poly-1-butene, 5% (accounting for the percentage of total feeding weight) of ultra-high molecular weight polyethylene (UHMWPE, viscosity-average molecular weight 1 × 10 6 , melting point 134), 3% (percentage of total feed weight) of antioxidant 1076 and 3% (percentage of total feed weight) of antistatic agent 600. Mix dryly in the mixer, join in twin-screw extruder (58mm in diameter, L / D=52, strong mixing type), then use metering pump, add 69% (accounting for total feeding weight) percentage) of liquid paraffin (dynamic viscosity 90cst / 40°C), melting and mixing the resin at 170°C and 156 rpm. The mixed resin solution was extruded through a T-die, and the cast sheet was cooled on a cooling roll with a surface temperature of 20° C. to obtain a thi...

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Abstract

The invention discloses a polyolefin battery diaphragm and a preparation method for the same. The preparation method is composed of the following steps of: (1) melting polyolefin resin, additive and dissolvent into uniform solution at 150-180 DEG C; (2) extruding the melt, which is obtained from the step (1), through a die head at 150-280 DEG C, and cooling and casting into a thick slice on a cooling roller, wherein the cooling temperature is in a range from -5 to 30 DEG C; (3) longitudinally stretching the thick slice obtained in the step (2), then, transversely stretching for the first time; (4) extracting the diaphragm obtained in the step (3) to remove the dissolvent, then, drying; (5) transversely stretching the diaphragm obtained in the step (4) for the second time, and executing heat shaping after stretching to obtain a polyolefin micro-porous membrane. With the preparation method provided by the invention, holes of the prepared micro-porous membrane are round, and have better ventilation effect; and mechanical strengths of the prepared micro-porous membrane in both longitudinal and transverse directions are uniform and consistent.

Description

technical field [0001] The invention relates to a polyolefin battery separator and a preparation method thereof, in particular to a polyolefin battery separator with high air permeability and uniform mechanical strength in all directions and a preparation method thereof. Background technique [0002] With the advancement of information, materials and energy technologies, lithium-ion batteries have become a hot spot in the research of new power supply technologies due to their advantages such as high specific energy, long cycle life, no memory effect, safety and reliability, and fast charging and discharging. With the further expansion of the application range of lithium-ion batteries, the demand for diaphragm materials will further increase. [0003] The battery separator refers to the polymer separator between the positive and negative electrodes of the lithium-ion battery. It is the most critical part of the lithium-ion battery and has a direct impact on battery safety and...

Claims

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Application Information

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IPC IPC(8): B29C69/00C08J9/28C08L23/00H01M8/02H01M2/16H01M8/0271
CPCY02E60/50Y02E60/12
Inventor 袁新豪古继峰
Owner XINXIANG ZHONGKE SCI&TECH
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