A lithium battery microporous diaphragm extrusion device

Abstract

The present invention discloses a lithium battery microporous diaphragm extrusion device, comprising a power device, an insulating device and a centrifugal device; the centrifugal device is connected to the output end of the power device through the insulating device; and the mold is mounted on the outside of the centrifugal device. The diaphragm of the present invention is prepared by a dry method, i.e., melt stretching, and the preparation process has low temperature requirements, and has the advantages of continuous production, simple process flow, low energy consumption, and no environmental pollution. At the same time, the prepared polypropylene microporous membrane has good mechanical properties, especially high transverse tensile strength and puncture strength, and has a good separation effect between the positive and negative electrodes of a high lithium battery, which can improve the overall quality of the lithium battery.

Description

Technical Field

[0001] The invention relates to the technical field of lithium battery microporous diaphragm production equipment, and in particular to a lithium battery microporous diaphragm extrusion device. Background Art

[0002] At present, the preparation methods of microporous membranes for diaphragms can be divided into two types: dry method (melt stretching) and wet method (thermal phase separation). Both methods include at least one orientation step to make the film have pores and improve the tensile strength. The preparation principle of the melt stretching method is that the polymer melt crystallizes under tensile stress during extrusion to form a lamellar structure perpendicular to the extrusion direction and arranged in parallel, and then obtains a hard elastic material after heat treatment. After the hard elastic polymer film is stretched, the lamellar crystals separate to form slit-shaped micropores, and then the microporous membrane is made by heat setting, but the temperature requirements of its preparation process are high and the production process is complicated. The basic process of thermal phase separation refers to dissolving the polymer in a high boiling point, low volatility solvent at high temperature to form a homogeneous liquid, and then cooling it down to cause the solution to produce liquid-solid phase separation or liquid-liquid phase separation, and then using a volatile reagent to extract the high boiling point solvent, and obtaining a polymer microporous membrane with a certain structure and shape after drying, but the preparation process requires a large amount of solvent, which is easy to cause environmental pollution and the process is complicated.

[0003] For example, invention number 2019106517565 discloses a three-layer co-extruded diaphragm production equipment for lithium batteries, including an extrusion platform, a first power motor, a second power motor, a first screw extruder, a second screw extruder, a casting platform, a melt pump, a casting machine, a swing device, a traction device, a winding mechanism, a metal separator and a three-cavity mold, wherein the bottoms of the first power motor, the second power motor, the first screw extruder and the second screw extruder are respectively fixedly connected to the top of the extrusion platform, and the output ends of the first power motor and the second power motor are respectively connected to the input ends of the first screw extruder and the second screw extruder. The problem of the layer-channeling phenomenon of raw materials after extrusion is solved, so that the raw materials are evenly distributed after being extruded by the extruder, and the raw materials are homogenized as a whole, and at the same time, the fluidity of the raw materials after extrusion can be improved, and the plasticization effect of the raw materials can be improved.

[0004] For example, invention number 2018103021648 discloses a method for preparing a composite polypropylene microporous membrane by a phase inversion method, and the prepared composite polypropylene microporous membrane and its use. The preparation method is that in the preparation process of a biaxially stretched polypropylene microporous substrate layer, a coating is introduced on one or both sides of the membrane surface by way one) immersion precipitation phase inversion method, or way two) dry phase inversion method, and the coating is stretched in the longitudinal / transverse direction or only in the transverse direction to achieve the preparation of the composite polypropylene microporous membrane. The method of the present invention simplifies the production process of the composite polypropylene microporous membrane, and the coating prepared has high porosity and uniform microporous structure, which can well improve the performance of the polypropylene microporous substrate layer. The composite polypropylene microporous membrane is used in lithium batteries. Since the coating layer is a polymer or composition that can form a gel with an electrolyte, the cycle and safety performance of the lithium battery can be improved. Summary of the invention

[0005] In order to overcome the above-mentioned technical defects, the purpose of the present invention is to provide a lithium battery microporous membrane extrusion device which adopts a dry method, i.e., melt stretching, and has a low temperature requirement in the preparation process, can be produced continuously, has a simple process flow, low energy consumption, and no environmental pollution, and the prepared polypropylene microporous membrane has good mechanical properties.

[0006] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0007] The technical solution is a lithium battery microporous membrane extrusion device, comprising a power device, an insulating device and a centrifugal device; the centrifugal device is transmission-connected to the output end of the power device through the insulating device; and a mold is mounted outside the centrifugal device.

[0008] Further preferably, the insulating device comprises a ring disk, an inner bracket, an inner insulating core and an insulating shell; the ring disk is arranged on the power device; the insulating shell is arranged on the ring disk; the inner bracket and the inner insulating core are sleeved on the output end of the power device.

[0009] Further preferably, the power device is an electric motor; the electric motor includes a housing, a stator, an end cover, a motor shaft, a bearing and a rotor.

[0010] Further preferably, the centrifugal device is a centrifugal tank.

[0011] Further preferably, the centrifugal tank is connected to the inner insulating core via a centrifugal tank bracket and a bearing gland.

[0012] Further preferably, the mold is connected to the insulating shell via a mold bracket.

[0013] The beneficial effects of the present invention are:

[0014] The diaphragm in the present invention is prepared by a dry method, i.e., melt stretching, and its preparation process has low temperature requirements and has the advantages of continuous production, simple process flow operation, low energy consumption, and no environmental pollution. At the same time, the prepared polypropylene microporous membrane has good mechanical properties, especially high transverse tensile strength and puncture strength, and has a good separation effect between the positive and negative electrodes of high-lithium batteries, which can improve the overall quality of lithium batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0016] Figure 1 It is a main structural schematic diagram of the present invention.

[0017] Markings in the figure:

[0018] Centrifuge tank 1a, mold 1b.

[0019] Centrifugal tank support 2a, bearing cover 2b, inner support 2c, ring plate 2d, support 2e;

[0020] Insulating shell 3a, inner insulating core 3b;

[0021] Housing 4a, stator 4b, end cover 4c, motor shaft 4d, bearing 4e, rotor 4f. DETAILED DESCRIPTION

[0022] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0023] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] Examples, such as Figure 1 As shown in the figure, the present invention is a lithium battery microporous membrane extrusion device, including a power device, an insulating device and a centrifugal device; the centrifugal device is transmission-connected to the output end of the power device through the insulating device; the centrifugal device is covered with a mold 1b.

[0025] The insulating device comprises a ring disk 2d, an inner bracket 2c, an inner insulating core 3b and an insulating shell 3a; the ring disk 2d is arranged on the power device; the insulating shell 3a is arranged on the ring disk 2d; the inner bracket 2c and the inner insulating core 3b are sleeved on the output end of the power device.

[0026] The power device is an electric motor; the electric motor includes a housing 4a, a stator 4b, an end cover 4c, a motor shaft 4d, a bearing 4e and a rotor 4f.

[0027] The centrifugal device is a centrifugal tank 1a.

[0028] The centrifugal tank 1a is connected to the inner insulating core 3b through the centrifugal tank bracket 2a and the bearing gland 2b.

[0029] The mold 1b is connected to the insulating shell 3a via a mold bracket 2e.

[0030] During operation, the motor shaft drives the centrifugal tank 1a to rotate at high speed. At the same time, 20KV high voltage electricity is added between the centrifugal tank 1a and the mold bracket 2e of the extruder, and a high voltage electric field is formed between the centrifugal tank 1a and the mold 1b. Under the action of centrifugal force and electric field, the raw material polypropylene of the microporous diaphragm flies out from the small holes on the wall of the centrifugal tank 1a, thereby adhering to the mold 1b, and finally forming a lithium battery microporous diaphragm. The present invention has the advantages of continuous production, simple process flow operation, low energy consumption, and no environmental pollution; at the same time, the polypropylene microporous membrane prepared by the device has good mechanical properties, especially high transverse tensile strength and puncture strength, and has a good separation effect between the positive and negative electrodes of the high lithium battery, which can improve the overall quality of the lithium battery.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A lithium battery microporous diaphragm extrusion device, characterized in that: It comprises a power device, an insulating device and a centrifugal device; the centrifugal device is transmission-connected with the output end of the power device through the insulating device, the insulating device comprises a ring disk, an inner bracket, an inner insulating core and an insulating outer shell; the power device is provided with a ring disk; the ring disk is provided with an insulating outer shell; the inner bracket and the inner insulating core are sleeved on the output end of the power device, the power device is a motor; the motor comprises a shell, a stator, an end cover, a motor shaft, a bearing and a rotor; a mold is sleeved on the outer surface of the centrifugal device, the centrifugal device is a centrifugal tank, the centrifugal tank is connected with the inner insulating core through a centrifugal tank bracket and a bearing pressure cover, and the mold is connected with the insulating outer shell through a mold bracket.

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