JP6903277B2 - Large-capacity capacitor device and secondary battery - Google Patents

Description

The present invention relates to an improvement of a large-capacity capacitor device in which a current collector layer is provided at a boundary surface between the first and second electrodes and a dielectric layer, and a secondary battery using the improved capacitor device.

There are the following patent documents as the prior art of the large-capacity capacitor device as described above.

Japanese Patent No. 5394987

By the way, in the above-mentioned large-capacity capacitor device, the large-capacity is a universal issue. An object of the present invention is to provide a large-capacity capacitor device provided with a current collector layer having a new configuration in order to solve this problem.

The present invention according to claim 1, wherein the dielectric layer is sandwiched between the first and second electrodes, and a current collecting layer is provided at the interface between the first and second electrodes and the dielectric layer. In, the current collecting layer has a structure in which micro to pico-sized conductive fine particles in which ceramic fine particles are coated with a metal are three-dimensionally interconnected by fusion, and gaps are formed between the conductive fine particles. It is a large-capacity capacitor device characterized by being present.
Further, the present invention according to claim 2 has a large capacity in which a dielectric layer is sandwiched between the first and second electrodes and a current collecting layer is provided at a boundary surface between the first and second electrodes and the dielectric layer. In the capacitor device, the current collecting layer has a structure in which micro to pico-sized conductive fine particles in which plastic fine particles are coated with metal are three-dimensionally interconnected by fusion, and gaps are formed between the conductive fine particles. It is a large-capacity capacitor device characterized by being.

Further, the present invention is a secondary battery configured to include the capacitor device and a charge / discharge control circuit.

The present invention can provide a large capacity capacitor device.

(A) is a basic configuration diagram of one embodiment, and (b) is a schematic cross-sectional view of a current collector layer. Both (a) and (b) are schematic cross-sectional views of other examples of the current collector layer. Is a basic configuration diagram of another example of the embodiment. (A) is a basic configuration diagram of a capacitor unit, and (b) is a basic configuration diagram of a secondary battery. It is a basic circuit diagram of a secondary battery. It is a charge / discharge characteristic diagram of a secondary battery.

FIG. 1A is a basic configuration diagram of an embodiment of the present invention.
In the capacitor device A of this embodiment, the dielectric layer 3 is sandwiched between the first and second electrodes 1 and 1, and a current collector layer is formed at the boundary surface between the first and second electrodes 1 and 2 and the dielectric layer 3. It is a basic configuration provided with 2 and 2, and is formed on one side of the insulating sheet base material 4. In the current collector layers 2 and 2, micro to pico-sized conductive fine particles 2a are three-dimensionally interconnected, and the space between the conductive fine particles 2a is 2d. The gap 2d is filled with a predetermined gas. Further, the first and second electrodes 1 and 1 and the conductive fine particles 2a of the current collector layers 2 and 2 are electrically connected. The dielectric layer 3 is made of a ceramic such as barium titanate.
The wording of micro size to pico size referred to here means that the maximum value of the three-way dimensions of the conductive fine particles 2a is less than 1 millimeter and 1 nanometer or more.
Further, the gas may be air or a specific gas used in the manufacturing process of the current collector layers 2 and 2. In short, the gaps between the conductive fine particles 2a may be filled with some kind of gas instead of solid or liquid.
Further, the first and second electrodes 1 and 1 are made of a metal such as copper or nickel or an alloy thereof, and are connected to the output lead wires 5 and 5.

FIG. 1B is a schematic cross-sectional view of the current collector layer.
As shown in this figure, the current collector layer 2 has a three-dimensional network-like structure in which micro to pico-sized conductive fine particles 2a are three-dimensionally interconnected, and the gap 2d between the conductive fine particles 2a is a predetermined gas. be satisfied. Further, the conductive fine particles 2a in this example are solid metal fine particles. The metal forming the fine particles is not particularly limited, and may be the same as or different from the metal forming the first and second electrodes 1, 1. However, it is desirable that the metal has electrical conductivity equal to or higher than that of the first and second electrodes 1, 1.
The current collector layers 2 and 2 using such metal fine particles can be formed by sputtering. That is, by rapidly solidifying the metal vapor on the base material (for example, a dielectric layer) in the form of fine particles, it is possible to form the current collector layers 2 and 2 as a sputtering forming layer, that is, a form laminated on the base material.
Alternatively, the kneaded product of the metal fine particles and the binder resin is made into a sheet by pressing or extrusion (green sheet), and this is heat-treated to near the melting point of the metal to eliminate the binder resin and fuse the metal fine particles to each other. It is possible to form sheet-shaped current collecting layers 2 and 2.
To supplement the manufacturing method of the capacitor device A, the first and second electrodes 1, 1 and the dielectric layers 2 and 2 can all be in the form of sheets prepared in advance, and can be obtained by sputtering or the like. It is also possible to form on the substrate in a predetermined order.

The present invention focuses on the current collector layers 2 and 2 having a peculiar structure as described above, and has the following effects. Further, the present invention does not limit any of the current collecting layers 2 and 2, that is, the first and second electrodes 1, 1 and the dielectric layer, and has electrodes and dielectric layers having various configurations. It can be widely applied to various capacitor devices.
According to the present invention, the three-dimensional network-like structure formed in the current collector layers 2 and 2 is a continuum of micro to pico-sized fine metal pieces and thin films, and therefore has a huge surface area in terms of volume ratio. If a metal having such a three-dimensional network structure is electrically connected to the first and second electrodes 1, 1, the surface of the first and second electrodes 1, 1 will be dramatically expanded. As a result, the capacitor device A has a large capacity.

1A and 1B are schematic cross-sectional views of another example of the current collector layer.
In the current collector layer 2 shown in FIG. 1A (a), the conductive fine particles 2a are formed by coating predetermined ceramic fine particles 2b with metal. The type of ceramic is not particularly limited.
The current collecting layer 2 using such conductive fine particles 2a can be formed by forming a kneaded product of a metal-coated ceramic fine particles 2b and a binder resin into a sheet and heat-treating the kneaded material to near the melting point of the metal. ..
The effect of this example is that the shape of the three-dimensional network structure can be freely controlled by appropriately selecting the shape, size, and amount of the ceramic fine particles 2b.
In the current collector layer 2 shown in FIG. 1A (b), the conductive fine particles 2a are formed by coating predetermined plastic fine particles 2c with metal. The type of plastic is not particularly limited. The current collector layer 2 of this example can also be formed by forming a sheet of a kneaded product of fine particles coated with a metal and a binder resin and heat-treating the kneaded product to near the melting point of the metal in the same manner as described above. The plastic portion of the plastic fine particles 2c may remain after the heat treatment or may disappear. The effect of this example is similar to the above.

FIG. 2 is a basic configuration diagram of another example of the embodiment.
In this embodiment, the capacitor devices A of the above embodiment are stacked in multiple layers and parallelized. Each of the parallelized capacitor devices A is the same as the above-described embodiment. The capacity of the capacitor device A can be further increased by parallelization by such multiple stacking.

3A and 3B are basic configuration diagrams of a capacitor unit and a secondary battery, respectively. Further, FIG. 4 is a basic circuit diagram of the secondary battery, and FIG. 5 is a charge / discharge characteristic diagram of the secondary battery.
This capacitor unit has a configuration in which the capacitor device A shown in FIG. 1A is wound in multiple cylinders. With such a configuration, a large-capacity and small-sized capacitor unit can be obtained.
The secondary battery B includes two or more capacitor devices A and a charge / discharge control circuit C. The charge / discharge control circuit C is a device that makes rapid charging and rapid discharging, which are general characteristics of a capacitor, gentle like a general secondary battery, and can be configured by a DC-DC converter or the like. Such a secondary battery B can replace a conventional lead, NiCd storage battery, lithium ion storage battery, or the like.
The secondary battery B may be formed by combining the capacitor device A shown in FIG. 2 and the charge / discharge control circuit C as described above.

Further, according to the present invention, the metal used for the current collector layer 2 is magnetized or superconducted, that is, the electron fluidity of the current collector layer 2 is increased, so that the capacitor device A and the secondary battery B are further enhanced. Performance improvement can be expected.

Further, according to the present invention, the ceramic fine particles 2b and the plastic fine particles 2c forming the conductive fine particles 2a are spherical, skeleton-shaped, tetrapod-shaped, long-fiber or short-fiber, or a combination thereof. Has. Further improvement in performance of the capacitor device A and the secondary battery B can be expected by any one of these shapes or a combination thereof.

A Capacitor device B Secondary battery C Charge / discharge control circuit 1 Electrode 2 Current collecting layer 2a Conductive fine particles 2b Ceramic fine particles 2c Plastic fine particles 3 Dielectric layer 4 Insulating sheet base material

Claims (5)

In a large-capacity capacitor device in which a dielectric layer is sandwiched between the first and second electrodes and a current collector layer is provided at a boundary surface between the first and second electrodes and the dielectric layer.
The current collector layer has a structure in which micro to pico-sized conductive fine particles in which ceramic fine particles are coated with metal are three-dimensionally interconnected by fusion , and there are voids between the conductive fine particles. A large-capacity capacitor device characterized by. In a large-capacity capacitor device in which a dielectric layer is sandwiched between the first and second electrodes and a current collector layer is provided at a boundary surface between the first and second electrodes and the dielectric layer.
The current collector layer has a structure in which micro to pico-sized conductive fine particles in which plastic fine particles are coated with metal are three-dimensionally interconnected by fusion , and there are voids between the conductive fine particles. A large-capacity capacitor device characterized by. In claim 1 or 2,
The large-capacity capacitor device is characterized in that it is formed on one surface of an insulating sheet base material and is wound in multiple cylinders to form a cylindrical capacitor unit. In claim 1 or 2,
The large-capacity capacitor device is a large-capacity capacitor device that is laminated in multiple layers and connected in parallel. A secondary battery configured to include the large-capacity capacitor device according to any one of claims 1 to 4 and a charge / discharge control circuit.

Images