Large-capacity capacitor device

Abstract

Provided is a large-capacity capacitor device excellent in terms of cost and performance. A multilayer capacitor comprises: a first electrode 1a formed from a conductive material; a second electrode 1b formed from a conductive material; a ferroelectric layer 3 formed to be sandwiched between the first electrode 1a and the second electrode 1b; and collector layers 2 formed respectively on the boundary surface between the first electrode 1a and the ferroelectric layer 3 and on the boundary surface between the second electrode 1b and the ferroelectric layer 3. The multilayer capacitor is characterized in that the ferroelectric layer 3 is formed as a ferroelectric containing a barium titanate-based ceramic material, the collector layers 2 are each formed from a particulate form base material made from a metal-based conductive substance, and the particulate form base material has nano-level outer dimensions and further has any one of a spherical shape, a hemispherical shape, and a semicylindrical shape, or a shape obtained by combination thereof, each having a diameter of 5 nm or more.

Description

Large-capacity capacitor device

[0001] The present invention relates to a large-capacity capacitor device provided with a current collector layer at the interface between a first electrode, a second electrode, and a dielectric layer.

[0002] Conventionally, the technology development of large-capacity capacitor devices and secondary batteries using the same has been carried out. As a conventional technology for storing electrical energy between electrodes facing each other with a dielectric interposed therebetween, there is the following Patent Document 1.

[0003] Utility Model Registration No. 3235703

[0004] In Patent Document 1, in order to increase the capacity of the capacitor device, efforts have been made to increase the surface area of the current collector layer, that is, to make it multilayered including small particles and focus on increasing the surface area. However, there are problems in terms of manufacturing methods and costs.

[0005] An object of the present invention is to provide a large-capacity capacitor device excellent in terms of cost and performance.

[0006] In order to achieve the above object, the large-capacity capacitor device according to the first invention includes a first electrode formed of a conductive material, a second electrode formed of a conductive material positioned to face the first electrode, a ferroelectric layer formed so as to be sandwiched between the first electrode and the second electrode, and a current collector layer formed at the interface between the first electrode and the ferroelectric layer and at the interface between the second electrode and the ferroelectric layer. In the multilayer capacitor, the ferroelectric layer is formed as a dielectric containing a barium titanate-based ceramic material, and the current collector layer is formed of a fine particle-shaped base material made of a metal-based conductive substance. The fine particle-shaped base material has an outer dimension at the nanometer level and further has a diameter of 5 nm or more, and has any one of a spherical shape, a hemispherical shape, or a kamaboko shape, or a combined shape thereof.

[0007] That is, by using a fine particle-shaped base material having a diameter of 5 nm or more for the current collector layer, the surface area of the current collector layer can be increased, and it becomes possible to accumulate a large amount of electrical energy between the electrodes. Furthermore, it is expected that the problems of the manufacturing method can be solved, and advantages can be ensured in terms of cost and performance.

[0008] The large-capacity capacitor device according to the second invention is characterized in that, in the first invention, the ferroelectric layer is formed by including one or more conductive materials selected from carbon, graphite, or conductive organic compounds as additives, and further, the ferroelectric layer is formed by uniformly aligning the conductive materials contained in the ferroelectric layer by applying mechanical vibration to the ferroelectric layer that takes frequency characteristics into account, or by applying an alternating magnetic field or alternating current to the ferroelectric layer.

[0009] The large-capacity capacitor device according to the third invention is characterized in that, in the first invention, the current collector layer is formed by including one or more conductive materials selected from carbon, graphite, or conductive organic compounds as additives, and further, the current collector layer is formed by uniformly aligning the conductive materials contained in the current collector layer by applying mechanical vibration to the current collector layer with respect to frequency characteristics, or by applying an alternating magnetic field or alternating current to the current collector layer.

[0010] The large-capacity capacitor device according to the fourth invention is characterized in that, in the first invention, the first electrode and the current collector layer are formed integrally, and the second electrode and the current collector layer are formed integrally.

[0011] The large-capacity capacitor device according to the fifth invention is characterized in that, in the first invention, a plurality of the multilayer capacitors are stacked in multiple layers, and the circuit configuration has a plurality of these multilayer capacitors connected in parallel.

[0012] The secondary battery according to the sixth invention is characterized by comprising a large-capacity capacitor device described in any of the first to fifth inventions, and a charge / discharge control circuit.

[0013] According to the present invention, by using a microparticle substrate with a diameter of 5 nm or more in the current collector layer, the surface area of ​​the current collector layer can be increased, making it possible to store a large amount of electrical energy between the electrodes and providing a large-capacity capacitor device. Furthermore, it is expected that the challenges of the manufacturing method will be overcome and advantages in terms of cost and performance will be secured.

[0014] This is a basic configuration diagram of a large-capacity capacitor device according to an embodiment of the present invention. This is a schematic cross-sectional view the current collector layer in a large-capacity capacitor device according to an embodiment of the present invention. This shows an example of a configuration diagram in which multiple multilayer capacitors are stacked in multiple layers and connected in parallel in a large-capacity capacitor device according to an embodiment of the present invention. This shows an example of a single capacitor prototyped based on the configuration diagram shown in Figure 4. This shows an example of a large-capacity capacitor device formed by integrating multiple single capacitors as shown in Figure 5. This shows a basic connection configuration as an example of when a large-capacity capacitor device is mounted on a vehicle.

[0015] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. It should be noted that the embodiments described below are merely examples provided to facilitate understanding of the present invention and do not limit it. That is, the present invention can be implemented with various modifications without departing from its core principles.

[0016] Figure 1 shows an example of a basic configuration diagram of a large-capacity capacitor device according to an embodiment of the present invention.

[0017] As shown in Figure 1, the large-capacity capacitor device is formed on one side of an insulating sheet substrate 4 as a laminated capacitor, comprising a first electrode 1a made of a conductive material, a second electrode 1b made of a conductive material positioned opposite the first electrode, a ferroelectric layer 3 formed between the first electrode 1a and the second electrode 1b, and a current collector layer 2 formed at the interface between the first electrode 1a and the ferroelectric layer 3 and the interface between the second electrode 1b and the ferroelectric layer 3.

[0018] The ferroelectric layer 3 is formed as a dielectric containing a barium titanate-based ceramic material. The current collector layer 2 is formed from a fine particle substrate made of a metallic conductive material. This fine particle substrate has nanoscale external dimensions and a diameter of 5 nm or more, and is spherical, hemispherical, or semi-circular in shape, or a combination thereof. Output lead wires 5 are led out from the first electrode 1a and the second electrode 1b.

[0019] Figure 2 shows an example of a schematic cross-sectional view of a large-capacity capacitor device according to an embodiment of the present invention, and Figures 2(a), (b), and (c) will be described in detail below. Hereinafter, the ferroelectric layer 3 is formed by planar printing, 3D printing, etching, lithography, stamping, deposition equipment, sputtering equipment, laser ablation, coating, spraying, and other printing methods.

[0020] Furthermore, the ferroelectric layer 3 is formed by including one or more conductive materials, selected from carbon, graphite, or conductive organic compounds, as additives. In addition, the ferroelectric layer 3 is formed by applying mechanical vibrations that take frequency characteristics into account to the ferroelectric layer 3, or by applying an alternating magnetic field or alternating current to the ferroelectric layer 3, thereby uniformly aligning the conductive materials contained in the ferroelectric layer 3. This makes it possible to efficiently store a large amount of electrical energy between the electrodes, thereby enabling the realization of a large-capacity capacitor device.

[0021] Figure 2(a) shows an example in which a current collector layer 2 having a spherical or hemispherical shape is formed at the interface between the first electrode 1a and the ferroelectric layer 3, and at the interface between the second electrode 1b and the ferroelectric layer 3. The current collector layer 2 is formed from a fine particle substrate made of a metallic conductive material, and this fine particle substrate has a spherical or hemispherical nanoscale external dimension. Furthermore, the diameter of the spherical or hemispherical shape is 5 nm or larger.

[0022] Figure 2(b) shows an example in which a current collector layer 2 having a semi-circular shape is formed at the interface between the first electrode 1a and the ferroelectric layer 3, and at the interface between the second electrode 1b and the ferroelectric layer 3. The current collector layer 2 is formed from a fine particle substrate made of a metallic conductive material, and this fine particle substrate has a semi-circular shape at the nanoscale. Furthermore, the diameter of the semi-circular shape is 5 nm or larger.

[0023] As shown in Figures 2(a) and 2(b), by using a microparticle substrate with a diameter of 5 nm or more in the current collector layer 2, and by making its shape spherical, hemispherical, or semi-circular, the surface area of ​​the current collector layer 2 can be increased, making it possible to store a large amount of electrical energy between the electrodes.

[0024] Furthermore, conventionally, in order to increase the surface area of ​​the current collector layer 2, the focus has been on increasing the surface area by creating multiple layers including smaller particles. However, from the perspective of manufacturing methods and costs, it has been verified that increasing the surface area with particles of approximately 5 nm or larger is the optimal method.

[0025] Figure 2(c) shows an example in which the first electrode 1a and the current collector layer 2 are formed as a single unit, and the second electrode 1b and the current collector layer 2 are formed as a single unit. This configuration is expected to offer advantages in terms of manufacturing process and cost.

[0026] Figure 3 shows an example of a schematic cross-sectional view of the current collector layer 2 in a large-capacity capacitor device according to an embodiment of the present invention. In the example in Figure 3(a), the current collector layer 2 is formed in the shape of multiple spherical or hemispherical shapes, and the diameter of each spherical or hemispherical shape is 5 nm or larger. In the example in Figure 3(b), the current collector layer 2 is formed in the shape of multiple semi-circular shapes, and the diameter of each semi-circular shape is 5 nm or larger.

[0027] Furthermore, the current collector layer 2 is formed from a conductive material, and as an example, the conductive material is manufactured by conventional planar printing, 3D printing, etching, lithography, stamping, deposition equipment, sputtering equipment, laser ablation, coating, spraying, or other printing methods.

[0028] Furthermore, the current collector layer 2 is formed by adding one or more conductive materials, selected from carbon, graphite, or conductive organic compounds, as additives. In addition, the current collector layer 2 is formed by applying mechanical vibration to the current collector layer 2, taking into account frequency characteristics, or by applying an alternating magnetic field or alternating current to the current collector layer 2, thereby uniformly aligning the conductive materials contained in the current collector layer 2. This makes it possible to efficiently store a large amount of electrical energy between the electrodes, thereby enabling the realization of a large-capacity capacitor device.

[0029] Figure 4 shows an example of a configuration diagram in which multiple multilayer capacitors are stacked in multiple layers and connected in parallel in a large-capacity capacitor device according to an embodiment of the present invention. By adopting such a configuration, it becomes possible to store a large amount of electrical energy between electrodes, thereby realizing a large-capacity capacitor device.

[0030] Figure 5 shows an example of a standalone capacitor prototyped based on the configuration diagram shown in Figure 4.

[0031] Figure 6 shows an example of a large-capacity capacitor device formed by integrating multiple individual capacitors as shown in Figure 5, and it can be mounted on vehicles such as automobiles and motorcycles.

[0032] Furthermore, it is possible to construct a secondary battery by combining the large-capacity capacitor described above with a charge / discharge control circuit. Examples of the use of this secondary battery are described below.

[0033] Figure 7 shows a basic connection configuration as an example of a large-capacity capacitor device mounted on a vehicle. As shown in Figure 7, the vehicle is equipped with a large-capacity capacitor unit 101, a charge / discharge control unit 102, a motor control unit 103, and a motor unit 104.

[0034] The large-capacity capacitor section 101 and the charge / discharge control unit 102 are combined to function as a secondary battery. There is a mechanism to slow down the rapid charging and rapid discharging that are typical characteristics of capacitors, and the charge / discharge control unit 102 can be configured as a DC-DC converter or the like.

[0035] When external power is input via the input line 20, the large-capacity capacitor section 101 is charged via the charge / discharge line 10 under the control of the charge / discharge control unit 102.

[0036] Next, when moving the vehicle, the charge / discharge control unit 102 extracts the necessary power from the large-capacity capacitor unit 101 via the charge / discharge line 10 and sends that power to the motor control unit 103 via the output line 11. The motor control unit 103 controls the drive of the motor unit 104 via the motor drive line 12 based on instructions from the operation control input line 21.

[0037] Furthermore, the charge / discharge control unit 102 has the function of outputting the power stored in the large-capacity capacitor unit 101 as a predetermined AC or DC via the output line 22.

[0038] Furthermore, when the motor unit 104 is rotated by an external force, it has a mechanism to generate regenerative power 15 when a negative load occurs, and this regenerative power 15 is sent to the charge / discharge control unit 102 via the motor control unit 103 and the transmission line 16. When the charge / discharge control unit 102 receives the regenerative power 15, it controls the system so that the large-capacity capacitor unit 101 is charged via the charge / discharge transmission line 10.

[0039] Furthermore, the charge / discharge control unit 102 has a function to charge the large-capacity capacitor unit 101 via the charge / discharge line 10 when power generated by a generator such as the solar panel generator 105 is input.

[0040] 1a First electrode 1b Second electrode 2 Current collector layer 3 Ferroelectric layer 4 Insulating sheet substrate 5 Output lead wire 10 Charge / discharge line 11 Output line 12 Motor drive line 15 Regenerative power 16 Line 20 External power input line 21 Operation control input line 22 External power output line 1a+2 First electrode and current collector layer integrated 1b+2 Second electrode and current collector layer integrated 101 Large capacity capacitor section 102 Charge / discharge control section 103 Motor control section 104 Motor section 105 Solar panel generator

Claims

1. A multilayer capacitor comprising: a first electrode formed of a conductive material; a second electrode formed of a conductive material positioned opposite the first electrode; a ferroelectric layer formed between the first electrode and the second electrode; and a current collector layer formed at the interface between the first electrode and the ferroelectric layer and the interface between the second electrode and the ferroelectric layer, wherein the ferroelectric layer is formed as a ferroelectric material containing a barium titanate-based ceramic material; and the current collector layer is formed from a fine particle substrate made of a metallic conductive material, the fine particle substrate having nanoscale external dimensions and a diameter of 5 nm or more, and having a shape that is spherical, hemispherical, or semi-circular, or a combination thereof.

2. A large-capacity capacitor device according to claim 1, wherein the ferroelectric layer is formed by adding one or more conductive materials selected from carbon, graphite, or conductive organic compounds as additives, and further, the ferroelectric layer is formed by uniformly aligning the conductive materials contained in the ferroelectric layer by applying mechanical vibration to the ferroelectric layer that takes frequency characteristics into account, or by applying an alternating magnetic field or alternating current to the ferroelectric layer.

3. A large-capacity capacitor device according to claim 1, wherein the current collector layer is formed by including one or more conductive materials selected from carbon, graphite, or conductive organic compounds as additives, and further, the current collector layer is formed by uniformly aligning the conductive materials contained in the current collector layer by applying mechanical vibration to the current collector layer that takes frequency characteristics into account, or by applying an alternating magnetic field or alternating current to the current collector layer.

4. A large-capacity capacitor device according to claim 1, characterized in that the first electrode and the current collector layer are formed integrally, and the second electrode and the current collector layer are formed integrally.

5. A large-capacity capacitor device according to claim 1, characterized in that a plurality of the multilayer capacitors are stacked in multiple layers, and the device has a circuit configuration in which these plurality of multilayer capacitors are connected in parallel.

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

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