CN112635913A - Composite diaphragm, battery and composite diaphragm manufacturing method - Google Patents

Abstract

The invention provides a composite diaphragm, a battery and a manufacturing method of the composite diaphragm, and relates to the technical field of batteries. The problem that the safety performance of the existing composite diaphragm is poor can be solved.

Description

Composite diaphragm, battery and composite diaphragm manufacturing method

Technical Field

The invention relates to the technical field of batteries, in particular to a composite diaphragm, a battery and a manufacturing method of the composite diaphragm.

Background

With the rapid development of lithium battery technology, the composite diaphragm is widely used, at present, most of the used composite diaphragms are oil-system coating diaphragms, the oil-system coating diaphragms have high static electricity, and the static electricity on the diaphragms can enable the surfaces of the diaphragms to adsorb dust and foreign matters due to the fact that the manufacturing environment of the batteries is dry, so that safety accidents are caused. Therefore, the existing composite diaphragm has the problem of poor safety performance.

Disclosure of Invention

The embodiment of the invention provides a composite diaphragm, a battery and a manufacturing method of the composite diaphragm, and aims to solve the problem that the existing composite diaphragm is poor in safety performance.

In a first aspect, an embodiment of the present invention provides a composite diaphragm, including a substrate layer, an insulating layer, and an antistatic layer, where the insulating layer is disposed on at least one surface of the substrate layer, the antistatic layer is disposed on the insulating layer, a plurality of antistatic structures are disposed on the antistatic layer, and a gap exists between any two of the antistatic structures.

Optionally, the shape of the antistatic structure comprises at least one of a circle, a square, and a triangle.

Optionally, the gap is 0.1 μm-10 cm.

Optionally, the material of the antistatic layer includes a carbon-based conductive material, a binder, and a solvent, and the ratio among the carbon-based conductive material, the binder, and the solvent is: 0.01-50%: 0.01-99.99%: 0 to 49.99 percent.

Optionally, the insulating layer comprises a ceramic layer, the ceramic layer is disposed on the substrate layer, and the antistatic layer is disposed on the ceramic layer.

Optionally, the insulating layer includes an organic layer, the organic layer is located on the substrate layer, the antistatic layer is located on the organic layer.

Optionally, the insulating layer includes ceramic layer and organic layer, the ceramic layer is located on the substrate layer, the organic layer is located on the ceramic layer, the antistatic layer is located on the organic layer.

Optionally, the insulating layer has a thickness of 0.5-16 μm.

In a second aspect, the present application also provides a battery comprising a composite separator as described in the first aspect.

In a third aspect, the present application also provides a method for manufacturing a composite diaphragm, including:

forming a substrate layer;

providing an insulating layer on at least one surface of the substrate layer;

form antistatic layer based on antistatic thick liquids, and will antistatic layer set up in on the insulating layer, be provided with a plurality of antistatic structure on the antistatic layer, arbitrary two there is the clearance between the antistatic structure.

The composite diaphragm provided by the embodiment of the invention comprises a substrate layer, an insulating layer and an antistatic layer, wherein the insulating layer is arranged on at least one surface of the substrate layer, and the antistatic layer is arranged on the insulating layer, wherein a plurality of antistatic structures are arranged on the antistatic layer, and a gap exists between any two antistatic structures.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a schematic structural diagram of a composite diaphragm provided in accordance with an embodiment of the present invention;

FIG. 2 is a second schematic structural diagram of a composite diaphragm provided in an embodiment of the present invention;

FIG. 3 is a schematic view of an antistatic structure provided by an embodiment of the present invention;

FIG. 4 is a second schematic view of an antistatic structure provided by an embodiment of the present invention;

FIG. 5 is a third schematic view of an antistatic structure provided by an embodiment of the present invention;

FIG. 6 is a fourth schematic view of an antistatic structure provided by an embodiment of the present invention;

FIG. 7 is a fifth schematic view of an antistatic structure provided by an embodiment of the present invention;

fig. 8 is a flowchart of a method for manufacturing a composite diaphragm according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and similar terms in the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. Also, the use of the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships are changed accordingly.

Referring to fig. 1-2, an embodiment of the present invention provides a composite diaphragm, including a substrate layer 101, an insulating layer 102, and an antistatic layer, where the insulating layer 102 is disposed on at least one surface of the substrate layer 101, the antistatic layer is disposed on the insulating layer 102, a plurality of antistatic structures 103 are disposed on the antistatic layer, and a gap exists between any two antistatic structures 103.

In this embodiment, the insulating layer 102 may be provided on one surface of the base material layer 101, or the insulating layers 102 may be provided on both surfaces of the base material layer 101, and it should be noted that the base material layer 101 itself is insulating, and therefore, when the insulating layer 102 is provided only on one surface of the base material layer 101, the safety of the remaining surface of the base material layer 101 is not affected.

The composite diaphragm can solve the problem of large static electricity of the composite diaphragm through the antistatic structures 103, the safety of the composite diaphragm is improved, and meanwhile, gaps exist between any two antistatic structures 103, so that the bonding area of the composite diaphragm is reserved through the gaps, and the bonding property of the composite diaphragm is guaranteed.

As shown in fig. 3 to 7, the shape of the antistatic structure 103 includes at least one of a circle, a square, and a triangle. The gaps between the antistatic structures 103 are 0.1 μm-10 cm.

The antistatic structures 103 may be arranged in an ordered manner or in a disordered manner when disposed. In one possible embodiment, as shown in fig. 3, the antistatic structure 103 may be provided in a shape of stripes, and the stripes may be provided as stripes distributed along the longitudinal direction of the composite membrane, wherein the width of the stripes may be 0.1 μm to 1cm, and the stripe interval may be 0.1 μm to 10cm, and when necessary, the width of the stripes and the stripe interval may be appropriately adjusted according to the requirements of the application scenario, which is only an example and is not limited herein.

In another possible embodiment, as shown in fig. 4, the antistatic structure 103 may be arranged in a grid shape formed by interlacing several stripes, wherein the angle of interlacing several stripes may be 90 °, and other angles may also be used, which is only an example and is not limited herein.

In yet another possible embodiment, as shown in fig. 5, the antistatic structure 103 may also be provided in a square shape, and in yet another possible embodiment, as shown in fig. 6, the antistatic structure 103 may also be provided in a circular shape. As shown in fig. 7, the antistatic structure 103 may also be provided in a circular shape and a square shape. The present invention is only exemplary and not limited, and as an alternative embodiment, the shape of the antistatic structure 103 may be adjusted accordingly in other possible embodiments, but any alternative is within the protection scope of the embodiments of the present application. Therefore, the antistatic structure is set into different shapes, and the degree of antistatic can be flexibly adjusted. Gaps can be reserved to expose partial insulating layers, and the adhesion of the composite diaphragm is guaranteed.

When the antistatic structure 103 is disposed on the insulating layer 102, the antistatic structure can be implemented by designing a gravure roll, for example, the gravure roll is designed to have the same shape as the antistatic structure 103, and the antistatic structure 103 is coated on the insulating layer 102 based on the designed gravure roll, which is convenient to implement.

Optionally, the material of the antistatic structure 103 of the antistatic layer includes a carbon-based conductive material, a binder, and a solvent, and the ratio among the carbon-based conductive material, the binder, and the solvent is: 0.01-50%: 0.01-99.99%: 0 to 49.99 percent.

In this embodiment, the carbon-based conductive material may be one or more selected from carbon black, carbon nanotubes, carbon fibers, graphite, fullerene, and the like. The adhesive can be one or more of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyacrylate, polymethyl methacrylate and polyacrylonitrile. The solvent can be one or more selected from acetone, N-methylpyrrolidone, N-dimethylacetamide, dimethylformamide, tetrahydrofuran and dimethyl sulfoxide.

Optionally, the thickness of the insulating layer 102 is 0.5-16 μm. The insulating layer 102 includes a ceramic layer 1021, the ceramic layer 1021 being provided on the base layer 101, and the antistatic layer being provided on the ceramic layer 1021.

In this embodiment, a ceramic layer 1021 is used for the insulating layer 102, wherein the thickness of the ceramic layer 1021 may be set to 0.5 to 8 μm. The ceramic layer 1021 contains inorganic particles made of at least one of alumina, silica, boehmite, zinc oxide, magnesium oxide, zirconium dioxide, and titanium oxide, and a small amount of an organic binder. The organic adhesive is composed of at least one of polyvinylidene fluoride, sodium carboxymethylcellulose, polyacrylate, polyacrylonitrile, polyvinyl alcohol, styrene-butadiene rubber, polyurethane and ethylene-acrylic acid copolymer.

Optionally, the insulating layer 102 includes an organic layer 1022, the organic layer 1022 is disposed on the base layer 101, and the antistatic layer is disposed on the organic layer 1022.

In this embodiment mode, an organic layer 1022 is used for the insulating layer 102, wherein the organic layer 1022 may be provided to have a thickness of 0.5 to 8 μm. The organic layer 1022 may be formed of at least one of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyacrylate, polymethyl methacrylate, and polyacrylonitrile.

Alternatively, the insulating layer 102 includes a ceramic layer 1021 and an organic layer 1022, the ceramic layer 1021 being provided on the base layer 101, the organic layer 1022 being provided on the ceramic layer 1021, and the antistatic layer being provided on the organic layer 1022.

In this embodiment, the insulating layer 102 is formed by using the ceramic layer 1021 and the organic layer 1022 in common, wherein the ceramic layer 1021 may have a thickness of 0.5 to 8 μm, the organic layer 1022 may have a thickness of 0.5 to 8 μm, the substrate layer 101 may have a thickness of 3 to 20 μm, and the substrate layer 101 may be a multilayer porous film composed of a single layer of polyethylene or polypropylene or a composite layer of polyethylene and polypropylene.

The embodiment of the invention also provides a battery, which comprises the composite diaphragm. Since the technical solution of this embodiment includes all technical solutions of the above embodiments, at least all technical effects of the above embodiments can be achieved, and details are not repeated here.

As shown in fig. 8, an embodiment of the present invention further provides a method for manufacturing a composite diaphragm, including:

step 801, forming a substrate layer;

step 802, an insulating layer is arranged on at least one surface of the substrate layer;

step 803, form the antistatic layer based on antistatic slurry, and will the antistatic layer set up in on the insulating layer, be provided with a plurality of antistatic structure on the antistatic layer, arbitrary two there is the clearance between the antistatic structure.

Specifically, in one possible embodiment, the carbon-based conductive material, the binder and the solvent are uniformly mixed to form a uniform and stable antistatic slurry; wherein, the carbon conductive material can be one or more of carbon black, carbon nano tube, carbon fiber, graphite, fullerene and the like. The adhesive can be one or more of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyacrylate, polymethyl methacrylate and polyacrylonitrile. The solvent can be selected from acetone, N-methylpyrrolidone, N-dimethylacetamide, dimethylformamide, tetrahydrofuran, and dimethyl sulfoxide.

The carbon-based conductive material is arranged in an antistatic structure with a solid proportion of 0.01-50 wt%, the binder is arranged in an antistatic structure with a solid proportion of 0.01-99.99 wt%, and the solvent is arranged in an antistatic structure with a solid proportion of 0-49.99 wt%.

And (3) coating the antistatic slurry containing the conductive material on the surface of the composite diaphragm containing the insulating layer to form a partially covered antistatic layer on the surface layer, and then drying in a vacuum oven to finally obtain the composite diaphragm.

Alternatively, in another possible embodiment, the ceramic alumina particles, binder, mixed and dispersed in a solvent may be mechanically stirred to obtain a ceramic slurry. Dispersing polyvinylidene fluoride serving as an adhesive in an N-methyl pyrrolidone NMP solvent, and fully stirring to form uniform and stable organic slurry. Mixing polyvinylidene fluoride serving as a binder and carbon nano tubes serving as a conductive agent according to the mass ratio of 40: 1 is dispersed in N-methylpyrrolidone NMP solvent and is fully stirred to form uniform and stable antistatic slurry.

And then, setting a substrate layer as a polyolefin material, wherein the porosity of the substrate layer is 35%, coating the obtained ceramic slurry on the surface of the substrate layer, and drying to obtain the composite diaphragm of the substrate layer and the ceramic layer. And coating the organic slurry on a ceramic layer, and drying to obtain the composite diaphragm with the structure of the base material layer, the ceramic layer and the organic layer. And finally, coating the antistatic slurry on the surface layer of the diaphragm by adopting a gravure coating mode, and drying to form the multilayer composite diaphragm with the conductive material partially covering the upper surface layer. Like this, can solve the big problem of compound diaphragm static through antistatic structure, promote compound diaphragm's security, simultaneously, there is the clearance between setting up two arbitrary antistatic structure, like this, but reserve compound diaphragm's bonding region through the clearance, guaranteed compound diaphragm's adhesion.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. The utility model provides a composite membrane, its characterized in that includes substrate layer, insulating layer and antistatic layer, the insulating layer set up in at least one surface of substrate layer, antistatic layer set up in on the insulating layer, be provided with a plurality of antistatic structure on the antistatic layer, arbitrary two there is the clearance between the antistatic structure.

2. The composite membrane of claim 1, wherein the shape of the antistatic structure comprises at least one of a circle, a square, and a triangle.

3. The composite separator membrane according to claim 1, wherein the gap is 0.1 μ ι η -10 cm.

4. The composite separator according to claim 1, wherein the material of the antistatic layer comprises a carbon-based conductive material, a binder and a solvent, and the carbon-based conductive material, the binder and the solvent are in a ratio of: 0.01-50%: 0.01-99.99%: 0 to 49.99 percent.

5. The composite separator of claim 1, wherein said insulating layer comprises a ceramic layer, said ceramic layer being disposed on said substrate layer, said antistatic layer being disposed on said ceramic layer.

6. The composite separator of claim 1, wherein the insulating layer comprises an organic layer disposed on the substrate layer, and the antistatic layer is disposed on the organic layer.

7. The composite separator according to claim 1, wherein said insulating layer comprises a ceramic layer and an organic layer, said ceramic layer being disposed on said substrate layer, said organic layer being disposed on said ceramic layer, said antistatic layer being disposed on said organic layer.

8. The composite separator according to claim 1, wherein the thickness of the insulating layer is 0.5-16 μm.

9. A battery comprising the composite separator of any one of claims 1-8.

10. A method of making a composite separator, comprising:

forming a substrate layer;

providing an insulating layer on at least one surface of the substrate layer;

form antistatic layer based on antistatic thick liquids, and will antistatic layer set up in on the insulating layer, be provided with a plurality of antistatic structure on the antistatic layer, arbitrary two there is the clearance between the antistatic structure.

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