Capacitor secondary battery having conductive fine particle-deposited current collector layer

Abstract

To provide a large-capacity capacitor device having a collector layer formed by depositing conductor fine particles.SOLUTION: Nanoparticles of a conductive material are laminated on the surface of titanium of an electrode material. As an example, nano-carbon is laminated. To solve the problem that, when a ceramic dielectric is laminated in the middle, an electrode material is laminated on the other side, and nano carbon particles are laminated between the ceramic dielectric and the electrode material, and they are combined, if they are pressed or bent for commercialization, dispersion is generated in the laminated fine particles, and characteristics are deteriorated, and as a countermeasure, coating by ceramic is performed to prepare a stable laminated structure. Further, in order to greatly improve the electrostatic capacity, nano-carbon fibers are compounded. According to the present invention, it is possible to greatly improve the electrostatic capacitance and to stably perform product manufacturing and mass production.SELECTED DRAWING: Figure 1

Description

Detailed Description of the Invention [Technical Field]

[0001] The present invention relates to an improvement in a large-capacity capacitor device in which a current collecting layer is provided on the boundary surface between the first and second electrodes and the dielectric layer, and to a secondary battery using the improved capacitor device. [Background technology]

[0002] The following patent documents are examples of prior art for such large-capacity capacitor devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5394987 Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of such a large-capacity capacitor device, increasing the capacitance is a universal issue. In response to this issue, an object of the present invention is to provide a large-capacity capacitor device having a current collecting layer with a novel configuration. [Means for solving the problem]

[0005] The present invention described in claim 1 is a large-capacity capacitor device having a dielectric layer sandwiched between first and second electrodes and a current collecting layer provided at the interface between the first and second electrodes and the dielectric layer, characterized in that the current collecting layer has a structure in which micro-sized conductive particles and nano-carbon fibers are interconnected in three dimensions by fusion, and the structure is coated and encapsulated in ceramic. Also, the large-capacity capacitor device is characterized in that the dielectric material is selected from ceramics, a mixture of ceramic fine powder and plastics, or plastics, depending on the application.

[0006] The present invention also provides a secondary battery comprising the capacitor device and a charge / discharge control circuit. [Effects of the Invention]

[0007] The present invention can provide a large-capacitor device. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1(a) is a basic configuration diagram of one embodiment, and FIG. 1(b) is a schematic cross-sectional view of a current collecting layer. [Figure 1A] 1(a) and 1(b) are schematic cross-sectional views of other examples of the current collecting layer. [Figure 2] 1 is a basic configuration diagram of another example of an embodiment in which nanocarbon fibers are mixed. [Figure 3] (a) is a basic configuration diagram of a capacitor unit, and (b) is a basic configuration diagram of a secondary battery. [Figure 4] FIG. 1 is a basic circuit diagram of a secondary battery. [Figure 5] FIG. 2 is a diagram showing charge and discharge characteristics of a secondary battery. DETAILED DESCRIPTION OF THE INVENTION

[0009] FIG. 1(a) is a basic configuration diagram of one embodiment of the present invention. The capacitor device A of this embodiment has a basic configuration in which a dielectric layer 3 is sandwiched between first and second electrodes 1, 1, and current collecting layers 2, 2 are provided at the interface between the first and second electrodes 1, 2 and the dielectric layer 3, and are formed on one side of an insulating sheet substrate 4. The current collecting layers 2, 2 are made of micro- and pico-sized conductive particles 2a that are interconnected in three dimensions, including nano- and pico-sized carbon fibers, and the conductive particles 2a are interconnected to form voids 2d between them. These voids 2d are filled with a specified gas. The first and second electrodes 1, 1 and the conductive particles 2a of the current collecting layers 2, 2 are electrically connected. The dielectric layer 3 is made of a ceramic such as barium titanate, or a mixture of ceramic powder and plastic, or made of plastic alone. The terms "micro-size" and "pico-size" used herein mean that the maximum values ​​of the three dimensions of the conductive fine particles 2a are less than 1 millimeter and not less than 1 nanometer. The gas may be air or a specific gas used in the manufacturing process of the current collecting layers 2, 2. In short, it is sufficient that the gaps between the conductive particles 2a are filled with some kind of gas, not with a solid or liquid. The first and second electrodes 1, 1 are made of a metal such as titanium, copper, nickel, or an alloy thereof, and are connected to output lead wires 5, 5.

[0010] FIG. 1(b) is a schematic cross-sectional view of the current collecting layer. As shown in this figure, the current collecting layer 2 has a three-dimensional network structure in which micro- and pico-sized conductive particles and fibers 2a are interconnected three-dimensionally, and the gaps 2d between the conductive particles and fibers 2a are filled with a predetermined gas. In addition, the conductive particles 2a in this example are solid carbon or The carbon and metal forming the particles are not particularly limited, and they 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 greater than that of the first and second electrodes 1, 1. The current collecting layers 2, 2 using such carbon and metal fine particles can be formed by sputtering. That is, by rapidly solidifying metal vapor into fine particles on a substrate (e.g., a dielectric layer), the current collecting layers 2, 2 can be formed in a form laminated on the substrate, i.e., as sputtered layers. Alternatively, a mixture of carbon and metal fine particles and a fibrous base material with a binder resin can be formed into a sheet (green sheet) by pressing or extrusion, and this can be heated to near the melting point of the metal, thereby eliminating the binder resin and fusing the metal fine particles together to form sheet-like current collecting layers 2, 2. To add a little more information about the manufacturing method of the capacitor device A, the first and second electrodes 1, 1 and the dielectric layers 2, 2 can all be prepared in sheet form, or they can be formed in a predetermined order on a substrate by lamination or the like.

[0011] The present invention focuses on the current collecting layers 2, 2 having the above-described unique structure, and has the following effects: Furthermore, the present invention does not impose any restrictions on components other than the current collecting layers 2, 2, i.e., the first and second electrodes 1, 1, dielectric layers, etc., and can be widely applied to various capacitor devices having electrodes and dielectric layers of various configurations. According to the present invention, the three-dimensional mesh structure formed on the current collecting layers 2, 2 is a continuous body of micro- and pico-sized fine carbon and metal pieces and thin films, and therefore has a large surface area relative to its volume. By electrically connecting such a three-dimensional mesh structure of carbon and metal to the first and second electrodes 1, 1, the surfaces of the first and second electrodes 1, 1 are dramatically expanded, thereby increasing the capacitance of the capacitor device A.

[0012] FIG. 2 is a basic structural diagram of another embodiment in which nanocarbon fibers are mixed. In this embodiment, the capacitor device A of the above embodiment is stacked in multiple layers and connected in parallel. Each of the paralleled capacitor devices A is the same as that of the above embodiment. By paralleling the capacitor devices A through such multi-layer stacking, the capacitance of the capacitor device A can be further increased.

[0013] Figures 3(a) and 3(b) are diagrams showing the basic configuration of a capacitor unit and a secondary battery, respectively. Figure 4 is a basic circuit diagram of a secondary battery, and Figure 5 is a diagram showing the charge and discharge characteristics of a secondary battery. This capacitor unit has a structure in which the capacitor device A shown in Fig. 1(a) is wound in a multiple cylindrical shape. With this structure, a large-capacity, small-sized capacitor unit can be obtained. The secondary battery B is composed of two or more capacitor devices A and a charge / discharge control circuit C. The charge / discharge control circuit C is a device that converts the rapid charging and rapid discharging characteristics of capacitors into a gentler state similar to that of general secondary batteries, and can be composed of a DC-DC converter or the like. Such a secondary battery B can replace conventional lead, nickel-cadmium, and lithium-ion batteries. The secondary battery B may be constructed by combining the capacitor device A shown in FIG. 2 with the charge / discharge control circuit C as described above.

[0014] Furthermore, according to the present invention, by magnetizing or superconducting the metal used in the current collecting layer 2, that is, by increasing the electron fluidity of the current collecting layer 2, further improvements in the performance of the capacitor device A and the secondary battery B can be expected. [Explanation of symbols]

[0015] A capacitor device B Secondary battery C Charge / discharge control circuit 1 electrode 2. Current collecting layer 2a Conductive fine particles 2b Nano-Pico Carbon Fiber 2c ceramic coating 3 Dielectric Layer 4. Insulating sheet substrate

Claims

1. A large-capacity capacitor device having a dielectric layer sandwiched between first and second electrodes and a current collecting layer disposed on the interface between the first and second electrodes and the dielectric layer, Regarding the conductive nanoparticle lamination of the current collector, the conductive nanoparticle lamination structure is covered with a non-conductive material coating such as ceramic to prevent disturbance and dispersion of the conductive nanoparticle lamination structure due to pressure compression and bending processing. The current collecting layer is a large-capacity capacitor device characterized in that nanocarbon particles and nano-sized carbon fibers are laminated on the surface of a titanium electrode, and are three-dimensionally interconnected by ceramic coating and fusion, with gaps between the conductive particles.

2. In a large-capacity capacitor device in which a dielectric layer is sandwiched between first and second electrodes and a current collecting layer is placed at the interface between the first and second electrodes and the dielectric layer, nano and pico carbon fibers are combined with the conductive material nanoparticle laminate of the current collector to significantly increase the capacitance. The dielectric material is selected from ceramic, a mixture of ceramic fine powder and plastic, or plastic alone.

3. In claim 1 or 2, The large-capacity capacitor device is characterized in that the large-capacity capacitor device is formed on one surface of an insulating sheet substrate and is wound in multiple cylindrical coils to form a cylindrical capacitor unit.

4. In claim 1 or 2, The large-capacity capacitor device is a large-capacity capacitor device in which multiple capacitors are stacked and connected in parallel.

5. A secondary battery comprising the large-capacity capacitor device according to any one of claims 1 to 4 and a charge / discharge control circuit.

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