CN109585897B - Flexible battery - Google Patents

Abstract

The present invention provides a flexible battery, comprising: a positive collector layer having a first outer surface and a first inner surface; a negative collector layer having a second outer surface and a second inner surface; a rubber frame clamped between the first inner surface and the second inner surface to form an enclosed area; the electrochemical system layer is arranged in the enclosed area and is adjacent to the side surface of the rubber frame; wherein, at least one of the first outer surface and the second outer surface is provided with a stress reinforcement material, the thickness ratio of the stress reinforcement material to the anode current collecting layer or the cathode current collecting layer is between 0.25 and 6, and the stress reinforcement material is arranged on the outer surface of at least one current collecting layer to improve the structural stress of the current collecting layer, so that the current collecting layer is not easy to generate wrinkles or unrecoverable deformation after the flexible battery is repeatedly bent.

Description

flexible battery

technical field

The present invention relates to a flexible battery, in particular to a flexible battery, which has a stress reinforcing material on the collector layer.

Background technique

In recent years, with the development of science and technology, various electronic devices, such as portable mobile phones, watches, cameras, video cameras, tablet computers, notebook computers, etc., have more and more styles, and many electronic devices have unique shapes, such as curved mobile phones. , wearable smart watches, smart bracelets, etc. These electronic devices require a power source, and electronic devices with unique shapes often require flexible batteries, and existing batteries are often too rigid to conform to the shape of these electronic devices, even if the battery is barely fit into the electronic device. , it may also cause unsatisfactory packaging of electronic equipment, therefore, a flexible battery that can be installed on a non-planar surface brings one of the solutions to this problem.

However, in the process of repeatedly bending the battery, the problems that the collector layer may cause after being stressed must be considered. At present, in order to make the battery more flexible, the current collector layer tends to be designed to be thinner and lighter to increase the degree of flexibility. produce acute angles. Moreover, the collector layer is usually made of metal material. When the metal material is subjected to an external force exceeding the elastic range, crystal slip may occur, or crystal dislocations may occur, making the surface of the collector layer unrecoverable. deformation.

When the above or other problems occur and the current collector layer is deformed, the current collector layer and the active material layer are often peeled off, thereby reducing the electric capacity of the battery and shortening the battery life.

SUMMARY OF THE INVENTION

In view of the above problems, the purpose of the present invention is to provide a flexible battery, which, on the premise of not hindering the bending ability of the battery, is provided with a stress reinforcing material on the current collector layer to increase the structural stress of the current collector layer and avoid current collection. The above-mentioned problem occurs in the layer.

In order to achieve the above purpose, the present invention proposes a flexible battery, which includes: a positive electrode current collecting layer, which has a first outer surface and a first inner surface; a negative electrode current collecting layer, which has a second outer surface and a second inner surface; a frame, sandwiched between the first inner surface and the second inner surface to form an enclosed area; an electrochemical system layer, arranged in the enclosed area and adjacent to the side surface of the plastic frame; and a stress reinforcement material, arranged On the first outer surface and/or the second outer surface, the ratio of the thickness of the stress reinforcing material to the positive electrode collector layer or the negative electrode collector layer is between 0.25 and 6.

The electrochemical system layer includes a positive electrode active material layer, a negative electrode active material layer and an electrical insulating layer, the positive electrode active material layer is adjacent to the first inner surface of the positive electrode current collecting layer, and the negative electrode active material layer is adjacent to the first inner surface of the negative electrode current collecting layer. The two inner surfaces are adjacent to each other, and the electrical insulating layer is sandwiched between the positive electrode active material layer and the negative electrode active material layer.

Wherein, the thickness of the positive electrode collector layer is between 5µm and 40µm.

Wherein, the thickness of the negative electrode collector layer is between 2µm and 20µm.

Among them, the thickness of the stress reinforcement material is between 10µm and 30µm.

Wherein, the stress reinforcing material is selected from polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PC), polystyrene (PS), polyimide (polyimide), nylon (nylon), polyethylene terephthalate (polyethylene terephthalate), polyurethane (polyurethane), acrylic (acrylic), epoxy resin (epoxy), silica gel (silicone) and the above combination.

Wherein, it further includes an adhesive layer between at least one of the stress reinforcement material and the first outer surface, and the stress reinforcement material and the second outer surface.

Wherein, the thickness of the adhesive layer is not more than 5 μm.

Wherein, the adhesive layer is selected from polyurethane, acrylic, epoxy, silicone and combinations thereof.

Wherein, the Young's modulus of the stress reinforcing material is similar to that of the positive electrode collector layer and the negative electrode collector layer.

Wherein, the enclosed area is airtight.

Continuing, the stress reinforcement material of the present invention has certain structural strength and ductility. The stress reinforcement material should be selected from a material with a Young's modulus similar to that of the collector layer, and the thickness of the stress reinforcement material is smaller than that of the collector layer. A stress reinforcing material is arranged on the layer and the negative electrode collector layer to improve the surface strength of the collector layer, so that the collector layer has a certain structural stress, and it is not easy to produce irreversible deformation during bending.

Description of drawings

1A-1C are schematic structural diagrams of an embodiment of the present invention.

FIG. 2 is a schematic structural diagram of another embodiment of the present invention.

Description of reference numerals

10 Flexible battery

12 Anode collector layer

120 first inner surface

122 first outer surface

14 Negative collector layer

140 Second inner surface

142 Second outer surface

16 plastic frame

18 Stress reinforcement

20 Electrochemical system layers

202 Positive electrode active material layer

204 Anode active material layer

206 Electrical insulating layer

22 Adhesive layer.

Detailed ways

The following describes in detail through specific embodiments, when it is easier to understand the purpose, technical content, characteristics and effects of the present invention.

In order to make it easier to understand the content of the present invention, it should be noted that the terms used in this specification should not be limited to general meaning or dictionary meaning, but should allow the inventor to define the terms appropriately for the best explanation. On the basis, explanations are made based on meanings and concepts consistent with the technical aspects of the present invention. Based on the above, the terms used in the specification are explained as follows:

1. "And/or" and "at least one of" include any and all combinations of one or more of the associated listed items.

2. "Current collector layer" refers to the area where electrons are collected and released, usually composed of metals, especially metals that do not react with active species. The collector layer mentioned in the present invention refers to a positive electrode collector layer and/or a negative electrode collector layer.

3. "Electrochemical system layer" means the area of electrochemical reaction. In the present invention, the current collector layer is not included in the electrochemical system layer, and the electron exchange occurs at the interface between the electrochemical system layer and the current collector layer.

4. The electrical insulation in the "electrical insulating layer" refers to isolating the flow of electrons, that is to say, the electrical insulating layer refers to the area that can isolate the flow of electrons but does not affect the flow of ions, usually sandwiched between the positive electrode and the negative electrode. , in the present invention, is used to isolate the electron flow between the positive electrode active material layer and the negative electrode active material layer, and it is selected from liquid, solid, colloidal and/or a combination of the above.

5. "Enclosed area" refers to an area that is isolated from the outside environment. In the present invention, the enclosed area is enclosed by the collector layer and the plastic frame, and the electrochemical system layer is arranged in the enclosed area. In other words, the electrochemical system layer of the present invention is formed by the collector layer and the plastic frame. The enclosure of the box is isolated from the outside world.

6. The position, size, range, etc. of each component shown in the drawings of the present invention may not indicate the actual position, size, range, etc. in some cases. The invention is not limited to what is disclosed in the drawings.

The object of the present invention is to provide a flexible battery, which is provided with a stress reinforcement material on the collector layer, and the stress reinforcement material at least needs to meet the following conditions:

a. The stress reinforcement material needs to have a certain structural strength to provide the structural stress of the current collector layer and avoid irreversible deformation of the flexible battery after bending.

b. In order to maintain the flexible characteristics of the flexible battery, the stress reinforcement material needs to have a certain flexibility.

Continuing, according to the above-mentioned spirit of the present invention, describe in more detail as follows:

Please also refer to FIGS. 1A to 1C , which are schematic structural diagrams of an embodiment of the flexible battery disclosed in the present invention. The flexible battery 10 includes a positive electrode current collecting layer 12 , a negative electrode current collecting layer 14 , a plastic frame 16 , a stress reinforcing material 18 and an electrochemical system layer 20 , wherein the stress reinforcing material 18 is arranged on the first outer surface of the positive electrode current collecting layer 12 122 , as shown in FIG. 1A , or the stress reinforcement material 18 is provided on the second outer surface 142 of the negative electrode current collector layer 14 , as shown in FIG. 1B , or the stress reinforcement material 18 is provided on the positive electrode current collection layer 12 . On the first outer surface 122 and on the second outer surface 142 of the negative electrode current collector layer 14, as shown in FIG. 1C. Please continue to refer to FIG. 1C , the positive electrode collector layer 12 , the negative electrode collector layer 14 and the plastic frame 16 form an enclosed area, and the electrochemical system layer 20 is arranged in the enclosed area. The electrochemical system layer 20 includes a positive electrode active material layer 202 , a negative electrode active material layer 204 and an electrical insulating layer 206 , wherein the positive electrode active material layer 202 is adjacent to the first inner surface 120 of the positive electrode collector layer 12 and the negative electrode active material layer 204 Adjacent to the second inner surface 140 of the negative electrode collector layer 14 , the electrical insulating layer 206 is sandwiched between the positive electrode active material layer 202 and the negative electrode active material layer 204 .

Continuing, the Young's modulus of the stress reinforcing material is similar to that of the collector layer, and the thicknesses of the stress reinforcing material and the collector layer are within a certain range. The reason is that if the Young's modulus of the stress reinforcing material is equal to If the current collector layer is too different, and the thickness of the stress reinforcing material is too different from that of the current collecting layer, the problem of different bending may occur when under stress. When the difference is too large, it will be affected by the surface deformation of each other, and the structure with a small deformation amount cannot continue to deform with the adjacent layer structure, resulting in the generation of lines or even cracks. Therefore, the stress reinforcing material is selected from a material whose Young's modulus is similar to that of the current collecting layer, and the thickness ratio of the stress reinforcing material and the current collecting layer is between 0.25 and 6.

For example, if stainless steel is selected as the material for the positive electrode collector layer, the thickness can be between 5µm and 15µm; if aluminum is selected as the material, the thickness can be between 25µm and 40µm; As the material, its thickness can be between 5µm and 15µm. If copper is selected as the material, its thickness can be between 2µm and 20µm. According to the above, since different materials have different material rigidity, the substrates of different materials The thickness range varies. For the stress reinforcement material, the preferred thickness is not more than 30µm, otherwise the too thick stress reinforcement material will become more difficult to bend due to its thickness, but for the too thin stress reinforcement material, for example, less than 10µm, it is difficult to provide the purpose of strengthening the structural strength. For the stress reinforcement material, the better thickness of the stress reinforcement material is between 10µm and 12µm, which can play a better effect. As for the material of the stress reinforcement material, Common and optional materials such as but not limited to polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PC), polystyrene (PS), polyamide Polyimide (polyimide), nylon (nylon), polyethylene terephthalate (polyethylene terephthalate), polyurethane (polyurethane), acrylic (acrylic), epoxy (epoxy), silicone (silicone) and other materials, but the The application is not limited to the above-mentioned types of materials.

In addition, the thickness of the current collector layer is not greater than that of the active material layer, because the active material layer is coated on the inner side of the current collector layer, and because the active material layer is composed of its own material, its bending ductility is quite low. If the thickness of the layer is too thick, not only the embrittlement of the active material layer is prone to occur, but also the active material layer pierces the collector layer, or the collector layer may be pulled too much to cause the collector layer to crack.

In addition, the stress reinforcement material is disposed on the collector layer by coating, spraying and printing, or an adhesive layer can be added between the stress reinforcement material and the collector layer for bonding Stress reinforcement and collector layer.

Please refer to FIG. 2 , which is a schematic structural diagram of a flexible battery with an adhesive layer added. The difference from FIGS. 1A to 1C is that the flexible battery 10 has an adhesive layer 22 , and the adhesive layer 22 is sandwiched on the first outer surface. 122 and the stress reinforcement material 18 and/or sandwiched between the second outer surface 142 and the stress reinforcement material 18, in other words, between the positive electrode current collector layer 12 and the stress reinforcement material 18, the negative electrode current collector layer 14 and the stress reinforcement material 18. At least one of the stress reinforcing members 18 is provided with an adhesive layer 22 . FIG. 2 only shows that the first outer surface 122 of the positive electrode current collector layer 12 and the second outer surface 142 of the negative electrode current collector layer 14 are provided with adhesive layers. 22 and the stress reinforcement material 18, of course, when the adhesive layer 22 may only exist between at least one of the positive electrode current collector layer 12 and the stress reinforcement material 18, the negative electrode current collection layer 14 and the stress reinforcement material 18, the actual situation Depending on the location of the stress reinforcement material 18 , for example, when the stress reinforcement material 18 is only provided on the first outer surface 122 , the adhesive layer 22 is also only provided between the first outer surface 122 and the stress reinforcement material 18 .

Then, the adhesive layer is composed of adhesive, and the adhesive can be composed of polyurethane, acrylic, epoxy, silicone, etc., and the thickness is not more than 5 μm.

As mentioned in point 5 of the glossary explanation, the electrochemical system layer is isolated from the outside world through the enclosure between the current collector layer and the plastic frame, so the enclosed area is sealed and not in contact with the external environment. That is to say, the plastic frame needs to have the function of blocking water vapor, and at the same time, it needs to have flexibility. Therefore, the material of the plastic frame of the present invention is selected from silica gel (silicone). still flexible. In addition, the plastic frame at least partially overlaps the positive electrode collector layer and the negative electrode collector layer in the orthographic direction, that is, the plastic frame does not need to completely overlap the positive electrode collector layer and the negative electrode collector layer in the orthographic direction.

Flexible batteries on the market use aluminum-plastic films as battery packaging materials to accommodate cathodes, anodes, separators, and electrolytes. Different from the present invention, the present invention uses the collector layer and the plastic frame as the package, that is to say, the collector layer not only collects and releases electrons, but also isolates the electrochemical system layer from the outside together with the plastic frame. The flexible battery on the top isolates the collector layer and the electrochemical system layer from the outside world with an aluminum-plastic film. Therefore, the present invention is completely different from the general flexible battery structure using aluminum plastic film.

To sum up, in the present invention, a stress reinforcing material is arranged on the collector layer to improve the surface strength of the collector layer. When the collector layer has a certain structural stress, it is not easy to produce wrinkles, sharp angles, or Unrecoverable deformation, so that the flexible battery can maintain good capacity and battery life even after repeated bending.

However, the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of implementation of the present invention. Therefore, all equivalent changes or modifications according to the claims of the present invention should be included in the protection scope of the present invention.

Claims (9)

1. A flexible battery, comprising:

a positive collector layer having a first outer surface and a first inner surface;

a negative collector layer having a second outer surface and a second inner surface;

a plastic frame sandwiched between the first inner surface and the second inner surface to form an enclosed region, wherein the positive current collecting layer, the negative current collecting layer and the plastic frame are packaging materials of the flexible battery; and

an electrochemical system layer arranged in the enclosed area and adjacent to the side surface of the rubber frame;

wherein, at least one of the first outer surface and the second outer surface is provided with a stress reinforcing material, and the Young modulus of the stress reinforcing material is similar to that of the material of the current collecting layer; the current collecting layer comprises the positive current collecting layer and/or the negative current collecting layer; the thickness ratio of the stress reinforcing material to the positive electrode current collecting layer or the negative electrode current collecting layer is between 0.25 and 6; the material of the rubber frame and the stress reinforcement material is silica gel.

2. A flexible battery according to claim 1, wherein said electrochemical system layer includes a positive active material layer, a negative active material layer and an electrically insulating layer sandwiched between said positive active material layer and said negative active material layer, said positive active material layer being adjacent to said first inner surface and said negative active material layer being adjacent to said second inner surface.

3. A flexible battery according to claim 1, wherein said positive current collector layer has a thickness in the range of 5 μm to 40 μm.

4. A flexible battery according to claim 1, wherein said negative current collector layer has a thickness in the range of 2 μm to 20 μm.

5. A flexible battery according to claim 1, wherein said stress reinforcement has a thickness of 10 μm to 30 μm.

6. The flexible battery of claim 1, further comprising an adhesive layer between the stress reinforcement and at least one of the first outer surface, the stress reinforcement, and the second outer surface.

7. A flexible battery according to claim 6, wherein said adhesive layer has a thickness of not more than 5 μm.

8. The flexible battery of claim 6, wherein the adhesive layer is selected from the group consisting of polyurethane, acrylic, epoxy, silicone, and combinations thereof.

9. The flexible battery of claim 1, wherein the enclosed region is hermetically sealed.

Images