JP7250391B1 - Sheet capacitor and battery - Google Patents

Abstract

A sheet capacitor, a battery, and a method for manufacturing a sheet capacitor are provided, which can reduce manufacturing costs. A sheet capacitor (A) includes a first electrode sheet (10), a second electrode sheet (20), and a dielectric sheet (30), which are superimposed on each other and adhered with an adhesive. On each surface of the first electrode sheet 10 and the second electrode sheet 20, current collection layers 11 and 21 are formed, respectively, to increase the effective area of the electrodes. The current-collecting layer-constituting member 1111 of the current-collecting layer 11 is metal microparticles adsorbed to the porous ceramic 111, and the particles of the porous ceramic 111 are placed on the surface of the first electrode sheet 10 together with the conductive adhesive 112. It is applied and fixed. The same applies to the current collection layer 21 . [Selection drawing] Fig. 2

Description

TECHNICAL FIELD The present invention relates to a sheet capacitor and a battery that can be widely used as a battery for electronic equipment and the like.

Capacitors can be said to have a smaller electrical capacity than secondary batteries that involve chemical reactions, such as lithium-ion batteries. are doing. As one technique for increasing the electric capacity of such a capacitor, there is a proposal to form a collection layer on the electrode surface of the capacitor to increase the electrode effective area (see Patent Documents 1 to 3).

Japanese Patent No. 6903276 Japanese Patent No. 6903277 Utility Model Registration No. 3216923

However, according to the above conventional example, it is necessary to use a large-scale semiconductor manufacturing apparatus to manufacture the capacitor, which makes it difficult to reduce manufacturing costs. Capacitors with large electric capacity are expected to be developed by combining various technologies, but it can be said that it is very difficult to reduce manufacturing costs. Also, unless such problems are solved, it is believed that capacitors will not be widely used as batteries.

SUMMARY OF THE INVENTION The present invention was created under the above background, and an object of the present invention is to provide a sheet capacitor and a battery that can be manufactured at a low cost.

A sheet capacitor according to the present invention is a capacitor having first and second electrodes and a dielectric sandwiched between the first and second electrodes, wherein the first electrode as the first electrode An electrode sheet, a dielectric sheet as the dielectric, and a second electrode sheet as a second electrode are superimposed on each other and adhered with an adhesive. Collecting layers are respectively formed on the interface with the dielectric sheet, and the current collecting layers are formed by combining the first and second electrode sheets with a conductive adhesive or a metal-containing binder. The current-collecting layer-constituting member is a metal fine particle adsorbed to a porous insulator, and the particles of the porous insulator are combined with the conductive adhesive or the metal-containing binder together with the first, They are each applied and fixed on the surface of the second electrode sheet.

In the case of the sheet capacitor having the above structure, since the electrode sheet and the dielectric sheet are bonded together with an adhesive, it is possible to manufacture easily by exclusively using the printing machine technology. In addition, unlike the prior art, it is not necessary to use a large-scale semiconductor manufacturing apparatus, and in this respect, it is possible to reduce manufacturing costs.

In addition, since the current collecting layers are formed on the first and second electrode sheets, the effective area on the electrode surface is increased, and accordingly the electric capacity is increased. Therefore, it is possible to improve the performance and reduce the cost of the capacitor.

Furthermore, since the current collection layer can be formed exclusively by using the printing machine technology, it is possible to further reduce the manufacturing cost in this respect. Therefore, it becomes possible to further improve the performance and reduce the cost of the capacitor, and eventually the capacitor will be widely used as a battery.

In particular, since a large number of fine metal particles are three-dimensionally and spaced widely over the surfaces of the first and second electrode sheets, the effective area on the electrode surface is further increased. , the electric capacity becomes larger. Moreover, it is still easy to prepare the current collecting layer. Therefore, it is possible to further improve the performance and reduce the cost of the capacitor.

A battery according to the present invention includes the sheet capacitor described above, and first and second external terminals electrically connected to the first and second electrode sheets of the capacitor, respectively.

In the case of the battery with the above configuration, since it is configured using the above sheet capacitor, it is possible to increase the capacity of the battery, reduce the cost, and reduce the size and weight, thereby expanding the range of use. .

Another battery according to the present invention comprises a capacitor having first and second electrodes and a dielectric sandwiched between the first and second electrodes, and charges and discharges power to and from the capacitor. On the surfaces of the first and second electrodes, current collecting layers are respectively formed on the interfaces with the dielectric, and the current collecting layers are formed by conductive adhesion of the current collecting layer-constituting members. It is fixed on the surface of each of the first and second electrodes by an agent or a metal-containing binder, and the current-collecting layer-constituting member is a metal fine particle adsorbed to a porous insulator, and the porous insulator Particles are coated and fixed on the surfaces of the first and second electrodes together with the conductive adhesive or metal-containing binder.

In the case of the battery having the above configuration, since it has a current collecting layer, the effective area on the electrode surface is increased, and accordingly the electric capacity is increased. Moreover, since the current collecting layer can be formed by exclusively using the printing machine technology, it is possible to reduce the manufacturing cost in this respect. Therefore, it is possible to improve the performance of the battery and reduce the cost.

In addition, since a large number of conductive fine particles are three-dimensionally and spaced widely over the surfaces of the first and second electrode sheets, the effective area on the electrode surface is further increased. , the electrical capacity is even greater. Moreover, it is still easy to prepare the current collecting layer. Therefore, it is possible to further improve the performance and reduce the cost of the battery.

1 is a schematic perspective view of a sheet capacitor or the like according to an embodiment of the present invention, and also shows an exploded perspective view thereof; FIG. (a) is a schematic cross-sectional view taken along the line CC in FIG. 1, (b) is a schematic enlarged view of a portion D in FIG. 2(a), and (c) is a schematic view showing particles of a porous ceramic. 1 is a diagram for explaining a method of manufacturing a sheet capacitor according to an embodiment of the present invention, and is a schematic configuration diagram showing a front stage of a sheet capacitor manufacturing apparatus; FIG. FIG. 2 is a schematic configuration diagram showing a middle section of the sheet capacitor manufacturing apparatus; FIG. 2 is a schematic diagram showing a rear stage of the sheet capacitor manufacturing apparatus; FIG. 4 is a perspective view of a sheet capacitor according to a modification of the invention; 1 is a schematic configuration diagram of a battery according to an embodiment of the invention; FIG. FIG. 5 is a schematic side view of a battery according to a modification of the invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the sheet capacitor A according to this embodiment includes a first electrode sheet 10 (referred to as a first electrode in other inventions below) and a second electrode sheet. 20 (referred to as a second electrode in the other inventions below) and a dielectric sheet 30 (referred to as a dielectric in the other inventions below) sandwiched between the first and second electrode sheets 10 and 20 . ) is a film capacitor. The first electrode sheet 10, the dielectric sheet 30, and the second electrode sheet 20 are superimposed on each other and adhered with an adhesive. Also, on the surfaces of the first and second electrode sheets 10 and 20, the first and second exterior films 40 and 50 are respectively superimposed and adhered with an adhesive. Each part will be described in detail below.

For convenience of explanation, the portion of the sheet capacitor A excluding the first and second exterior films 40 and 50 will be referred to as capacitor A1.

For the first electrode sheet 10, a metal foil (for example, copper foil, nickel foil, etc.) having a thickness suitable for the capacitance of the capacitor is used. On the surface of the first electrode sheet 10, a collector layer 11 is formed on the interface with the dielectric sheet 30 as shown in FIG. Note that the thicknesses of the first and second electrode sheets 10, 20, etc. in FIG. 2 are not shown accurately due to the convenience of drawing.

The collector layer 11 is formed using a well-known technique (see, for example, Patent Documents 1 to 3) for enlarging the electrode effective area of a capacitor to increase its electric capacity. In this example, the current-collecting layer-constituting member 1111 is metal fine particles adsorbed to the porous ceramic 111, and is uniformly applied and fixed to the surface of the first electrode sheet 10 by the conductive adhesive 112. .

2B and 2C schematically show particles of the porous ceramic 111. FIG. The porous ceramic 111 uses silica (SiO ₂ ) having a large number of nano-order micropores on its outer surface (see Japanese Patent No. 5978479, etc. for a method of manufacturing porous silica). The current collecting layer-constituting member 1111 is metal fine particles of the same material as the first electrode sheet 10, and has a particle diameter of about 200 to 2000 nm. In this example, the micropores existing on the surface of the porous ceramic 111 are adsorbed by a well-known vacuum adsorption method or the like. Particles obtained by pulverizing the solid of the porous ceramic 111 are mixed in the conductive adhesive 112 and uniformly applied on the surface of the first electrode sheet 10 to be fixed. As a result, a large number of current-collecting layer-constituting members 1111 are three-dimensionally arranged widely over the surface of the first electrode sheet 10 in a state in which intervals between adjacent fine particles are secured. The current collection layer 11 is composed of the above-described current collection layer-constituting member 1111 and the like. The amount of the current-collecting layer-constituting member 1111 mixed in the current-collecting layer 11 , the material of the conductive adhesive 112 , and the like should be determined according to the electrical characteristics required for the current-collecting layer 11 .

The conductive adhesive 112 is used to facilitate the application and adhesion of the current-collecting layer-constituting member 1111 and the like, and to provide electrical connection between the current-collecting layer-constituting member 1111 and the first electrode sheet 10. It is used. It is often difficult to obtain low-cost materials that are suitable for such applications. In that case, it is better to use a metal mixed binder instead of the conductive adhesive. The metal-mixed binder is a binder in which the necessary amount of metal fine particles is mixed in order to obtain a predetermined conductivity. It is conceivable to use a binder containing resin or the like as a main component mixed with fine metal particles of the same material as the first electrode sheet 10 . In that case, unlike the conductive adhesive, it becomes easy to match the material of the metal fine particles to be mixed in the binder with the first electrode sheet 10 .

A method for forming such a current collecting layer 11 will be described in a method for manufacturing the sheet capacitor A, which will be described later.

The second electrode sheet 20 and the collector layer 21 formed thereon have the same configuration as the first electrode sheet 10 and the collector layer 11, and thus the description thereof will be omitted.

As for the dielectric sheet 30, as shown in FIG. 2, it is a dielectric sheet having a thickness corresponding to the withstand voltage of the capacitor. In this embodiment, a half-sheet 31 having the same material as the dielectric sheet 30 and having a thickness of about half and a half-sheet 32 having the same thickness are overlapped and adhered with an adhesive. is a commercially available barium titanate sheet. As for the adhesive material for bonding the half-sheets together, it is preferable to use an adhesive material having electrical properties close to the dielectric constant of the material of the dielectric sheet 30 . As for the adhesive for bonding the half sheet 31 and the current collecting layer 11, it is preferable to use a material suitable for the material to be bonded.

The first exterior film 40 is an insulating sheet having a thickness suitable for the intended use. In this embodiment, a commercially available resin sheet is used. As for the adhesive for adhering the surfaces of the first exterior film 40 and the first electrode sheet 10, it is preferable to use an adhesive suitable for the material to be adhered.

Since the second exterior film 50 has the same configuration as the first exterior film 40, the description thereof will be omitted.

The sheet capacitor A having such a structure is manufactured using the sheet capacitor manufacturing apparatus shown in FIGS. A method for manufacturing the sheet capacitor A will be described below.

Reference numeral 100 in FIG. 3 denotes the base material of the first electrode sheet 10 wound into a roll with a predetermined length. The base material of the electrode sheet 20 is shown as 100' in the drawing. Reference numeral 300 in the figure indicates the base material of the half sheet 31 wound into a roll with a predetermined length. The base material of the half sheet 32 is shown as 300' in the figure.

In FIG. 3, α indicates the conductive adhesive 112 in which the particles of the porous ceramic 111 are evenly mixed, before curing, and is supplied to the roll coater 1 as the adhesive α. In the figure, β indicates an adhesive before curing for adhering the first electrode sheet 10 (or the second electrode sheet 20) and the half sheet 31 (or the half sheet 32). , is supplied to the adhesive roll 3 as the adhesive β.

First, as shown in FIG. 3, the surface of a base material 100 is uniformly coated with an adhesive .alpha. by a roll coater 1, and the coated surface is heated by a heating device 2 such as a heater. Then, the particles of the porous ceramic 111 are fixed together with the conductive adhesive 112 on the surface of the substrate 100 . The current collecting layer 11 is thus formed on the surface of the first electrode sheet 10 . As for the heating device 2, it is preferable to set the heating temperature to be suitable for reducing the electric resistance and the like by removing the excess conductive adhesive 112 applied on the surface of the base material 100. FIG. In the case of using the above-described metal mixed binder instead of the conductive adhesive, it is the same as the above.

Thereafter, the adhesive β is uniformly applied on the surface of the base material 100 by the adhesive roll 3, and the surfaces of the base material 100 and the base material 300 are overlapped by the pressure roller 4 and adhered with the adhesive β. The substrate 400 is obtained by winding this into a roll.

That is, the base material 400 has the half sheet 31 adhered to the surface of the first electrode sheet 10 and has a predetermined length. Also, the base material 400' has the half sheet 32 adhered to the surface of the second electrode sheet 20 and has a predetermined length.

Substrate 400 ′ is also fabricated in the same manner as substrate 400 . That is, the base material 400' is prepared by fixing the particles of the porous ceramic 111 together with the conductive adhesive 112 on the surface of the base material 100' and then attaching the base material 300'. 1, the half sheets 31 and 32 of the dielectric sheet 30 are overlaid on the surfaces of the second electrode sheets 10 and 20 and adhered with the adhesive β).

The substrates 400, 400' are heated in an annealing furnace to crystallize the materials of the half sheets 31, 32 and increase their dielectric constant.

In FIG. 4, γ is an adhesive for adhering the half sheet 31 on the surface of the first electrode sheet 10 and the half sheet 32 on the surface of the second electrode sheet 20, and is adhered to the adhesive roll 5. supplied as agent γ.

A base material 500 is produced using the base material 400 and the base material 400' produced as described above. That is, as shown in FIG. 4, the surface of the base material 400′ (corresponding to the surface of the half sheet 32) is uniformly coated with the adhesive γ by the adhesive roll 5, and the surface of the base material 400′ is coated by the pressure roller 6. (corresponding to the surface of the half sheet 32) and the surface of the base material 400 (corresponding to the surface of the half sheet 31) are overlapped and adhered with an adhesive γ (thereby connecting the first electrode sheet 10 and the second electrode sheet 10). A dielectric sheet 30 is arranged between the electrode sheet 20). The substrate 500 is obtained by winding this into a roll. The base material of the capacitor A1 is formed in this manner and wound into a roll.

Reference numeral 600 in FIG. 5 indicates the base material of the first exterior film 40 wound into a roll with a predetermined length. Reference numeral 700 in the figure denotes the base material of the second exterior film 50 wound into a roll with a predetermined length.

In FIG. 5, ε is an adhesive for adhering the first exterior film 40 to one surface of the capacitor A1 and the second exterior film 50 to the other surface of the capacitor A1. Each is supplied as an adhesive ε.

A base material 800 is produced using the base material 500 produced as described above and the base materials 600 and 700 prepared separately. That is, as shown in FIG. 5, the adhesive ε is uniformly applied to each surface of the base material 500 by the adhesive rolls 7 and 8, and the pressure roller 9 is used to bond the base material 500 and the base materials 600 and 700 together. While aligning the respective surfaces of , they are overlapped with each other and adhered with an adhesive ε. The substrate 800 is obtained by winding this into a roll. This becomes the base material of the sheet capacitor A wound into a roll with a predetermined length.

The sheet capacitor A shown in FIG. 1 is obtained by cutting the base material 800 produced in the above flow into a predetermined length using a cutting device (not shown). When such a sheet capacitor A is used as a battery, which is a secondary battery, it is necessary to electrically connect positive and negative external terminals to the first and second electrode sheets 10 and 20, respectively. However, since the surfaces of the first and second electrode sheets 10 and 20 are covered with the first and second exterior films 40 and 50, respectively, the configuration of electrical connection up to the external terminals becomes complicated. easy. A sheet capacitor A' according to a modified example in which this point is improved will be described with reference to FIG.

The sheet capacitor A' has the same structure as the sheet capacitor A, except that openings 41 and 51 for exposing electrodes are formed on the surfaces of the first and second exterior films 40 and 50, respectively. ing. That is, the surfaces of the first and second electrode sheets 10 and 20 are partially exposed through the openings 41 and 51 .

An embodiment of a battery B suitable for such a sheet capacitor A' will be described with reference to FIG.

The battery B comprises a sheet capacitor A' arranged in a case, and external terminals arranged on the outer surface of the case and electrically connected to the first and second electrode sheets 10, 20 of the sheet capacitor A', respectively. 900, 900, and is configured to charge and discharge electric power to the sheet capacitor A'. The electrical connection between the sheet capacitor A' and the external terminals 900, 900 is provided by elastic contact pieces 910, 910 that make bias contact with the surfaces of the first and second electrode sheets 10, 20 of the sheet capacitor A'. through an outside lead.

Note that the sheet capacitor A' can also be applied to a form in which the capacitor A1 is multi-layered. In this case, a plurality of capacitors A1 are connected in series, which makes it easy to increase the voltage. On the other hand, when a plurality of capacitors A1 are connected in parallel to increase the capacity, it is preferable to use the following battery B'.

A battery B' according to a modification will be described with reference to FIG.

The battery B' consists of a plurality of sheet capacitors A arranged in an overlapping manner, and an insulating rectangular parallelepiped having a U-shaped cross section with one end open, and ends made of resin or the like attached to both ends of the sheet capacitor A. It comprises caps 1000 and 1000 and screw-like external terminals 1100 and 1100 fixed outwardly to the center of the other end surface of the end cap 1000 . Inside the end cap 1000, internal electrodes 1200, 1200 are provided that can contact the ends of the first and second electrode sheets 10, 20 with both ends of the sheet capacitor A attached. Electrical connection between each sheet capacitor A and the external terminal 1100 is made through an internal electrode 1200 and a connection line (not shown).

In the case of the sheet capacitor A (or A') configured as described above, since the current collection layers 11 and 21 are provided, the electric capacity is large, and in this respect, it is possible to improve the performance. In addition, cost reduction can be achieved in that the current collecting layers 11 and 21 can be easily manufactured by exclusively using the printing machine technology. Furthermore, the configuration is simple, and it is possible to reduce the size and weight of the device by thinning it. Therefore, when the sheet capacitor A or the like is used as a battery, there are advantages similar to those described above. Due to its characteristics, it is applied to, for example, backup batteries for personal computers, batteries for automobiles, bicycles, drones, etc., as well as batteries powered by renewable energy. In addition, it is expected to be applied to new applications because it is thin, small, and light. For example, it can be put into the cover of a personal computer, put the sheet capacitor into the case of an electronic device or the thickness of a solar panel housing, or put it into a rucksack, a bag, clothes, or the like.

The battery B (or B') is provided with a sheet capacitor A (or A'), and the first electrode sheet 10, the dielectric sheet 30, and the second electrode sheet 20 are superimposed with an adhesive. It may also be in the form of a battery with a capacitor that was attached but does not have such features. A battery according to another invention will be described with reference to FIGS. 1 and 2. FIG.

A capacitor A″ provided in the same battery has first and second electrodes 10 and 20 and a dielectric 30 sandwiched between the first and second electrodes 10 and 20. Collecting layers 11 and 21 are formed on the surfaces of the second electrodes 10 and 20, respectively, at the interface with the dielectric 30. The collecting layer 11 has a collecting layer-constituting member 1111 which is electrically conductively adhered. It is fixed on the surface of the first electrode 10 by an agent 112. The current-collecting layer-constituting member 1111 is metal fine particles adsorbed to the porous ceramic 111 as a porous insulator. is applied and fixed on the surface of the first electrode 10 together with a conductive adhesive 112. The porous ceramic 111 and the conductive adhesive 112 on the surfaces of the first and second electrodes 10 and 20 As for the coating method, it is preferable to use a coater roll or the like as in the case of the sheet capacitor A. The collector layer 21 has the same structure as the collector layer 11 .

In the case of the battery with the above configuration, since the current collection layers 11 and 21 are formed on the surfaces of the first and second electrodes 10 and 20, the effective area on the electrode surfaces is increased. The electric capacity increases with the increase. Moreover, since the current collecting layers 11 and 21 can be formed exclusively by using the printing machine technology, it is possible to reduce the manufacturing cost in this respect. Therefore, it is possible to improve the performance of the battery and reduce the cost.

The sheet capacitor and battery according to the present invention are not limited to the above embodiments. For example, the electrode sheet may be made of any material, and may be made of a resin film having a metal coating on the outer surface. good. Regarding the dielectric sheet, there is no question about the material and the like. Moreover, the form which abbreviate|omits the exterior film may be used. As for the method of superimposing the first and second electrode sheets and the dielectric sheet on each other and adhering them with an adhesive, it is preferable to adopt a method according to the type of sheet. As for the adhesive material for bonding each sheet, it is preferable to use an adhesive material corresponding to the material of each sheet. Sheet capacitors can be used not only as batteries but also as capacitors, in which case they may have a cylindrical shape or the like.

As for the current collecting layer, the material of the current collecting layer-constituting member and the preparation method are not limited. For example, in addition to a form in which metal fine particles are adsorbed on a porous resin or the like and fixed on the surfaces of the first and second electrode sheets with a conductive adhesive or the like, the inner wall surface of the micropores on the surface of the porous insulator may be used. A form in which a metal film is formed as a member constituting the current collecting layer may be used. Also, it may be formed on the boundary surface on the surface of the dielectric sheet instead of the first and second electrode sheets. Also in this case, the current-collecting layer-constituting member and the first and second electrode sheets are electrically connected through a conductive adhesive or the like. Regardless of the material, the fine metal particles may be coated with a metal film only on the surface of the fine particles, or may be formed on the surfaces of the first and second electrode sheets by sputtering or the like.

The battery according to the present invention is not limited to the above embodiments, and the configuration of capacitors, the number and connection method, the presence or absence of an exterior film, the shape of external terminals, and the like are not limited. The design of the first and second electrodes and the collecting layers formed on the surfaces of the electrodes may be changed in the same manner as in the case of the sheet capacitor. Also, the shape and size may be in accordance with the standard of ordinary dry batteries.

A sheet capacitor 10: first electrode sheet 11: current collecting layer 111 porous ceramic
1111 Current collection layer constituent member 112 Conductive adhesive
20: Second electrode sheet 21: Current collecting layer
30: Dielectric sheet B Battery

Claims (3)

A capacitor having first and second electrodes and a dielectric sandwiched between the first and second electrodes, wherein a first electrode sheet as the first electrode and a dielectric as the dielectric and a second electrode sheet as a second electrode are superimposed on each other and adhered with an adhesive. On the surfaces of the first and second electrode sheets, the dielectric sheet current collecting layers are respectively formed on the interfaces between the current collecting layers, the current collecting layer constituent members are respectively fixed on the surfaces of the first and second electrode sheets with a conductive adhesive or a metal-containing binder, The current-collecting layer-constituting member is metal fine particles adsorbed to a porous insulator, and the particles of the porous insulator are placed on the surfaces of the first and second electrode sheets together with the conductive adhesive or the metal-containing binder. The sheet capacitors are each coated and fixed to the . A battery comprising: the sheet capacitor of claim 1; and first and second external terminals electrically connected to the first and second electrode sheets of said capacitor, respectively. A battery that includes a capacitor having first and second electrodes and a dielectric sandwiched between the first and second electrodes, and charges and discharges power to and from the capacitor, wherein the first and second electrodes current-collecting layers are respectively formed on the interface with the dielectric. The current-collecting layer-constituting member is a metal fine particle adsorbed to a porous insulator, and the particles of the porous insulator are the conductive adhesive or the metal-containing binder and a battery fixed by coating on the surfaces of the first and second electrodes respectively .

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