TWI639269B - Flexible battery - Google Patents

Abstract

The invention provides a flexible battery, which is provided with a stress reinforcing material on the outer surface of at least one collector layer to improve the structural stress of the collector layer, so that the collector layer is not easy to be bent after repeated bending. Produces wrinkles or unrecoverable deformation.

Description

Flexible battery

The present invention relates to a flexible battery, and more particularly to a flexible battery having a stress reinforcing material on a collector layer.

In recent years, with the development of technology, various electronic devices, such as portable mobile phones, watches, cameras, cameras, tablets, notebook computers, etc., have become 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 power supplies. Electronic devices with unique shapes often require flexible batteries. Conventional batteries are often too rigid to conform to the shape of these electronic devices, even if the battery is barely installed in the electronic device. It may also cause the packaging of electronic equipment to be unsatisfactory. Therefore, it can be set in a non-planar flexible battery to solve this problem.

However, in the process of the battery being subjected to repeated bending, it is necessary to consider the problems that may occur after the collector layer is subjected to stress. At present, in order to make the battery more flexible, the collector layer tends to be lighter and thinner to increase the bendability. However, when the collector layer is bent by force, it is easy to be squeezed by the pole layer. Produces an acute angle. Furthermore, the collector layer usually uses a metal material. When the metal material is subjected to an external force exceeding the elastic range, a crystal slip may occur, or a problem of crystal dislocations may occur, so that the surface of the collector layer may not be generated. The deformation of the recovery.

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

In view of the above problems, an object of the present invention is to provide a flexible battery which is provided with stress on the collector layer without impeding the bending ability of the battery. Strong material to improve the structural stress of the collector layer and avoid the above problems in the collector layer.

In order to achieve the above object, the present invention provides a flexible battery comprising: a positive electrode collector layer having a first outer surface and a first inner surface; a negative electrode collector layer having a second outer surface and a second inner surface; a frame sandwiched between the first inner surface and the second inner surface to form a sealing area; an electrochemical system layer disposed in the enclosed area; and a stress reinforcing material disposed on the first outer surface and/or the second On the outer surface.

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

In addition, the stress reinforcing material of the present invention has certain structural strength and ductility, and the stress reinforcing material should select a material whose Young's modulus is similar to the Young's modulus of the collector layer, and the thickness of the stress reinforcing material is smaller than the collector layer. By providing a stress reinforcing material on the positive electrode current collecting layer and the negative electrode current collecting layer, the surface strength of the current collecting layer is increased, the current collecting layer is provided with a certain structural stress, and the unrecoverable deformation is less likely to occur at the time of bending.

The purpose, technical contents, features and effects achieved by the present invention will be more readily understood by the detailed description of the embodiments.

10‧‧‧Flexible battery

12‧‧‧ positive current 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‧‧‧Electrical system layer

202‧‧‧positive active material layer

204‧‧‧Negative active material layer

206‧‧‧Electrical insulation

22‧‧‧Adhesive layer

1A to 1C are schematic views showing the structure of an embodiment of the present invention.

Figure 2 is a schematic view showing the structure of another embodiment of the present invention.

In order to make the content of the present invention easier to understand, it should be noted that the terms used in the present specification should not be limited to the general meaning or the meaning of the dictionary, but should allow the inventor to properly define the term for the best interpretation. Based on the meanings and concepts that are consistent with the technical aspects of the present invention, it is explained. Based on the above, the following uses the terms used in the specification:

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

2. "Collector" means the area where electrons are collected and released, usually by gold. The genus is composed of a metal which does not react with the active material. The collector layer described in the present invention means a positive electrode collector layer and/or a negative electrode collector layer.

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

4. Electrical insulation in "electrical insulation" means the flow of isolated electrons. That is to say, the electrically insulating layer refers to the area where the flow of electrons can be isolated but does not affect the flow of ions. Usually, it is sandwiched between the positive electrode and the negative electrode. In the present invention, the electron flow between the positive electrode active material layer and the negative electrode active material layer is isolated, and is selected from the group consisting of liquid, solid, colloidal, and/or combinations thereof.

5. "Enclosed area" means an area that is isolated from the external environment. In the present invention, the enclosing area is surrounded by the collector layer and the plastic frame, and the electrochemical system layer is disposed in the enclosing area. In other words, the electrochemical system layer of the present invention is provided by the collector layer. The enclosure with the plastic frame is isolated from the outside world.

6. The position, size, range, and the like of each component shown in the drawings of the present invention may not represent actual positions, sizes, ranges, and the like. The invention is not limited to the disclosure in the drawings.

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

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

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

Next, in accordance with the spirit of the present invention described above, it will be described in more detail as follows:

Please refer to FIG. 1A to FIG. 1C simultaneously, 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 collector layer 12, a negative electrode current collector layer 14, a plastic frame 16, a stress reinforcement material 18, and an electrochemical system layer 20, wherein the stress reinforcement material 18 is disposed on the first electrode of the positive electrode current collector layer 12. On the surface 122, as shown in FIG. 1A, or the stress reinforcing material 18 is disposed on the second outer surface 142 of the negative electrode collector layer 14, as shown in FIG. 1B, and the stress reinforcing material 18 is disposed. On the first outer surface 122 of the positive electrode collector layer 12 and the second outer surface 142 of the negative electrode collector layer 14, as shown in FIG. 1C. Referring to FIG. 1C , the positive electrode collector layer 12 , the negative electrode collector layer 14 and the bezel 16 form a sealing area, and the electrochemical system layer 20 is disposed in the enclosing 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 current collecting 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 electrically insulating layer 206 is interposed between the positive electrode active material layer 202 and the negative active material layer 204.

In the continuation, the Young's modulus of the stress reinforcement material is similar to the Young's modulus of the collector layer, and the thickness of the stress reinforcement material and the collector layer is in a certain range, because the stress is strengthened. The Young's modulus of the material is too different from the Young's modulus of the collector layer, and the thickness of the stress reinforcement is too different from that of the collector layer, and the stress may be different when subjected to stress. When the difference between the shape variable of the reinforcing material and the shape variable of the collector layer is too large, it will be affected by the surface deformation of each other, and the structure with smaller deformation will not be deformed with the adjacent layer structure, and the generation of the texture will occur. Or even a break. Therefore, the stress reinforcing material selects a material whose Young's modulus is similar to the Young's modulus of the collector layer, and the thickness ratio of the stress reinforcing material to the collector layer is between 0.25 and 6.

For example, if the positive electrode collector layer is made of stainless steel, the thickness may be between 5 μm and 15 μm. If aluminum is selected as the material, the thickness may be between 25 μm and 40 μm, and if the negative electrode collector layer is stainless steel. For the material, the thickness may be between 5 μm and 15 μm. If copper is selected as the material, the thickness may be between 2 μm and 20 μm. According to the above, since different materials have different material rigidity, the substrates of different materials are used. The thickness range is not the same. For the stress reinforcing material, the preferred thickness is not more than 30 μm, otherwise the excessively thick stress reinforcing material may become difficult to bend due to its own thickness, but for a thin thickness of the stress reinforcing material, for example, less than 10 μm, it is difficult to provide the purpose of strengthening the structural strength. For the stress reinforcing material, the thickness of the preferred stress reinforcing material is between 10 μm and 12 μm, which can exert a better effect, and in terms of the material of the stress reinforcing material, Common and optional materials such as, but not limited to, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyethylene Aceene (PE), polypropylene (PC), polystyrene (PS), polyimide, nylon, polyethylene terephthalate, polyurethane, pressure Materials such as acrylic, epoxy, silicone, etc., but the actual application is not limited to the above types of materials.

In addition, the thickness of the collector layer is not larger than the active material layer because the active material layer is applied to the inner side of the collector layer, and since the active material layer is composed of its own material, its bending ductility is rather low, if active If the thickness of the material layer is too thick, the problem of brittle cracking of the active material layer may occur, and the active material layer may pierce the collector layer, or the collector layer may excessively pull the active material layer to cause the collector layer to be broken. .

In addition, the stress reinforcing material is disposed on the collector layer by coating, spraying, printing, or the like, or an adhesive layer may be added between the stress reinforcing material and the collector layer to Adhesive stress reinforcement and collector layer.

Please refer to FIG. 2 , which is a schematic structural view of a flexible battery incorporating an adhesive layer, which differs from FIG. 1A to FIG. 1C in that the flexible battery 10 has an adhesive layer 22 and the adhesive layer 22 is interposed. Between the first outer surface 122 and the stress reinforcing material 18 and/or between the second outer surface 142 and the stress reinforcing material 18, in other words, between the positive electrode current collecting layer 12 and the stress reinforcing material 18, and the negative electrode At least one of the collector layer 14 and the stress reinforcement 18 is provided with an adhesive layer 22, and FIG. 2 shows only the first outer surface 122 of the positive electrode collector layer 12 and the second outer surface of the negative electrode collector layer 14. The adhesive layer 22 and the stress reinforcing material 18 are provided on the 142. Of course, when the adhesive layer 22 is present, only the positive electrode current collector layer 12 and the stress reinforcing material 18, the negative electrode current collecting layer 14, and the stress reinforcing material 18 may be present at least. Between the two, the actual situation depends on the position where the stress reinforcement 18 is disposed. For example, when the stress reinforcement 18 is disposed only on the first outer surface 122, the adhesive layer 22 is also disposed only on the first outer surface 122 and the stress reinforcement. Between 18.

In the continuation, the adhesive layer is composed of an adhesive, and the adhesive system may be composed of polyurethane, Acrylic, epoxy, silicone, etc., and has a thickness of not more than 5 μm.

According to the vocabulary explanation point 5, the electrochemical system layer is isolated from the outside by the sealing of the 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 water blocking gas and needs to have flexibility. Therefore, the material of the plastic frame of the invention is selected from silicone, and the silicone can achieve the function of water blocking gas, and It still has flexibility after aging. In addition, the plastic frame is at least partially overlapped in the positive projection direction with the positive electrode collector layer and the negative electrode collector layer, that is, in the orthographic projection direction, the plastic frame does not need to completely overlap the positive electrode collector layer and the negative electrode collector layer. .

The flexible battery on the market uses an aluminum plastic film as a packaging material for the battery to accommodate a cathode, an anode, a separator, and an electrolyte. Different from the present invention, the present invention uses a collector layer and a plastic frame as a package, that is, the collector layer not only collects and releases electrons, but also isolates the electrochemical system layer from the outside world together with the plastic frame, and reflects the market. The flexible battery is isolated from the outside by the aluminum film. Therefore, the present invention is quite different from the flexible battery structure in which an aluminum plastic film is generally used.

In summary, the present invention provides a stress reinforcing material on the collector layer to improve the surface strength of the collector layer. When the collector layer has a certain structural stress, it is less likely to cause wrinkles and sharp angles when bent. Or unrecoverable deformation, so that even if the flexible battery is repeatedly bent, it can maintain good capacitance and battery life.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Therefore, any changes or modifications of the features and spirits of the present invention should be included in the scope of the present invention.

Claims (11)

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 frame sandwiched between the first inner surface and the second inner surface to form a surrounding area; and an electrochemical system layer disposed in the enclosed area and adjacent to the side of the frame a surface; wherein a stress reinforcement is disposed on at least one of the first outer surface and the second outer surface, and a thickness ratio of the stress reinforcement to the positive current collector layer or the negative current collector layer is 0.25 To 6. The flexible battery according to claim 1, wherein the electrochemical system layer comprises a positive active material layer, a negative active material layer and an electrical insulation sandwiched between the positive active material layer and the negative active material layer. a layer, the positive active material layer is adjacent to the first inner surface, and the negative active material layer is adjacent to the second inner surface. The flexible battery according to claim 1, wherein the positive electrode collector layer has a thickness of from 5 μm to 40 μm. The flexible battery according to claim 1, wherein the negative electrode collector layer has a thickness of from 2 μm to 20 μm. The flexible battery according to claim 1, wherein the stress reinforcing material has a thickness of from 10 μm to 30 μm. The flexible battery according to claim 1, wherein the stress reinforcing material is selected from the group consisting of polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PC), Polystyrene (PS), polyimide, nylon, polyethylene terephthalate, polyurethane, acrylic, epoxy (epoxy) ), silicone and combinations of the above. The flexible battery of claim 1, further comprising an adhesive layer between the stress reinforcement and the first outer surface, at least one of the stress reinforcement and the second outer surface. The flexible battery according to claim 7, wherein the adhesive layer has a thickness of not more than 5 μm. The flexible battery of claim 7, wherein the adhesive layer is selected from the group consisting of polyurethane, Acrylic, epoxy, silicone, and combinations thereof. The flexible battery according to claim 1, wherein the Young's modulus of the stress reinforcing material is similar to the Young's modulus of the positive electrode collector layer and the negative electrode collector layer. The flexible battery of claim 1, wherein the enclosed area is hermetic.