JP2013065674A - Electric energy storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric energy storage device having a compact size and high capacity, from which large electric energy can be obtained.SOLUTION: In an electric energy storage device 1 including a first electrode 4, a dielectric layer 6 and a second electrode 7, a fine particulate layer 5 comprising metal fine particles 5a is formed between the first electrode 4 and the dielectric layer 6 and between the second electrode 7 and the dielectric layer 6. Furthermore, the dielectric layer 6 is configured of lamination of fine particles having sizes of about 40 nm or lower, or an alternate lamination of a thin film and a fine particle.

Description

  The present invention relates to an electrical energy storage device.

In recent years, as electric energy storage devices, lithium-ion batteries have increased in capacity due to the need for large-capacity batteries represented by electric vehicles, and electric double-layer capacitor batteries with expanded electrolytic capacitors have been actively developed.
Among them, there are development examples using magnetic materials (for example, see Patent Documents 1 to 3).
The invention described in Patent Document 1 relates to “an apparatus for storing electric energy”, and “a first magnetic unit having a first magnetic section and a second magnetic section, a third magnetic section, and a fourth magnetic section. A second magnetic unit having a plurality of magnetic sections, and a dielectric section disposed between the first magnetic unit and the second magnetic unit, wherein the dielectric section stores electrical energy, and a dipole is provided. The first magnetic section, the second magnetic section, the third magnetic section, and the fourth magnetic section having the current leakage prevention prevent current leakage. "
The invention described in Patent Document 2 relates to an “apparatus for storing electrical energy”, and includes “a first magnetic section, a second magnetic section, and a first magnetic section and a second magnetic section. A dielectric section disposed on the substrate, storing electrical energy by the dielectric section, and preventing current leakage by the first and second magnetic sections each having a dipole.
The invention described in Patent Document 3 relates to an “apparatus for storing electrical energy”, and includes “a first magnetic section, a second magnetic section, and a first magnetic section and a second magnetic section. A diode barrier formed by a junction surface between the semiconductor section and the first magnetic section and the second magnetic section, from the first magnetic section to the second magnetic section. Prevent current flow and store electrical energy. "

JP 2008-177535 A JP 2008-177536 A JP 2009-049351 A

In the technologies described in Patent Documents 1 to 3, although the development progress of large-capacity lithium ion batteries is large, there are problems of overcharge, ignition during an accident, deterioration due to charge / discharge, or a long charge time. At the same time, depletion of lithium resources becomes a problem.
For this reason, electric double layer large-capacity capacitors that have a long battery life and shortened charging time have been developed, and electric double layer capacitor batteries with large-scale capacitance have been realized. It is said that about one-twentieth of the capacity is the limit, and there are significant development issues for application to automobiles.
In the past, increasing the surface area of the electrode material has been the main development item in order to increase the capacitance. For lithium ion secondary batteries, the selection of an ionic substance with high storage efficiency or the nanocarbon electrode material for an electric double layer capacitor Has been focused on development.
On the other hand, the multilayer ceramic capacitor has been miniaturized as a high-voltage noise filter member for mounting on a substrate as much as possible. Therefore, the problem is to increase the capacitance per unit volume.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electrical energy storage device that is small in size and can obtain a large amount of electrical energy.

  In order to solve the above-mentioned problem, the invention described in claim 1 includes a first electrode formed of a conductive material, a second electrode positioned to face the first electrode, and the first electrode. An electrical energy storage device comprising a dielectric layer formed so as to be sandwiched between one electrode and the second electrode, and between the first electrode and the dielectric layer and the second layer Metal, metal complex or conductive ceramic fine particles are formed as an electrode fine particle surface area expanding layer between the electrode and the dielectric layer.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the fine particle layer is formed by a nanotechnology forming layer as a nanofiber, a quantum dot or a quantum protrusion layer.

  The invention described in claim 3 is the invention described in claim 1, characterized in that a plurality of the nanotechnology-forming layers are formed.

  The invention described in claim 4 is the invention described in claim 1, characterized in that the nanotechnology forming layer is formed singly or in a plurality of layers, and a thin film metal is incorporated between the layers.

  The invention described in claim 5 is characterized in that, in the invention described in claim 1, the nanotechnology forming layer is formed of a magnetic material.

  The invention described in claim 6 is characterized in that, in the invention described in claim 5, the nanotechnology forming layer is magnetized.

  The invention according to claim 7 is a first electrode formed of a conductive material, a second electrode positioned to face the first electrode, the first electrode, and the second electrode. A dielectric layer formed by a quantum protrusion layer including a thin film, a fine particle, or a quantum dot in an electrical energy storage device comprising a dielectric layer formed between the electrodes It is characterized by comprising an improvement layer.

  The invention according to claim 8 is characterized in that the dielectric layer is formed of a composite of a quantum protrusion layer including any one of a thin film, fine particles, and quantum dots.

  ADVANTAGE OF THE INVENTION According to this invention, provision of the electrical energy storage apparatus which can obtain a small-sized and large capacity | capacitance electrical energy is realizable.

1 is an example of a cross-sectional view schematically showing an electrical energy storage device according to the present invention.

(First embodiment)
Next, a first embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a cross-sectional view schematically showing an electrical energy storage device according to a first embodiment of the present invention.
An electrical energy storage device 1 shown in FIG. 1 includes a support substrate 2, a buffer layer 3, a first electrode 4, a fine particle layer 5, a dielectric layer 6, a second electrode 7, terminals 8, 9, It has.

The support substrate 2 is not particularly limited, but for example, a silicon single crystal, a SiGe single crystal, a GaAs single crystal, an InP single crystal, an SrTiO ₃ single crystal, an MgO single crystal, an LaAlO ₃ single crystal, a ZrO ₂ single crystal, or MgAl ₂ O ₄ single crystal, NdGaO ₃ single crystal, NdAlO ₃ single crystal, LaGaO ₃ single crystal, or the like. Among these, a silicon single crystal is most preferable because of its low cost. Further, the thickness of the support substrate 2 is not particularly limited as long as the mechanical strength of the entire electric energy storage device 1 can be secured, and may be set to about 10 to 1000 μm, for example.

The buffer layer 3 is formed as an upper layer of the support substrate 2 and serves as a barrier layer that prevents the reaction between the support substrate 2 and the electrode thin film constituting the first electrode 4. A material for forming the buffer layer 3 can be formed of, for example, ZrO ₂ , ReO ₂ , ReO ₂ —ZrO ₂ , MgAlO ₄ , γ-Al ₂ O ₃ , SrTiO ₃ , LaAlO _3, or the like. Specifically, a material having excellent lattice matching with the support substrate 2 and a thermal expansion coefficient between the support substrate 2 and the thin film material constituting the dielectric layer 6 is selected from these, and the buffer is selected. Layer 3 is preferably formed. The buffer layer 3 may have a single layer structure or a multilayer structure. The thickness of the buffer layer 3 is not particularly limited as long as the function as a barrier layer for preventing the reaction between the support substrate 2 and the electrode thin film constituting the first electrode 4 can be secured, and for example, 1 to 1000 nm. What is necessary is just to set to a grade.

  The buffer layer 3 may not be provided. When the buffer layer 3 is not provided, the first electrode 4 is formed on the surface of the support substrate 2.

  The first electrode 4 is formed as a thin film on the upper layer of the buffer layer 3. For example, platinum (Pt), ruthenium (Ru), rhodium (Rh), palladium (Pd), iridium (Ir), gold (Au), silver It can be formed of a conductive metal such as (Ag), copper (Cu), or nickel (Ni). Specifically, it is preferable to select and form a material excellent in lattice matching with the support substrate 2 or the buffer layer 3 from these materials. Further, the thickness of the electrode thin film of the first electrode 4 is not particularly limited as long as it can function as one electrode of the thin film capacitor, and may be set to about 500 to 1000 nm, for example.

The fine particle layer 5 as the metal fine particle layer, which is an electrode fine particle surface area expansion layer, controls the particle diameter on the surface (upper layer) of the first electrode 4 by sputtering the metal fine particles 5a (see FIG. 1). While molding. The particle size is set at about 20 to 2000 nm, and the number of layers is, for example, about 5 layers, which are combined and laminated to a thickness of about 100 nm to 1 μm (FIG. 1 is an example of 2 layers). The material of the fine particles 5a has a function of enhancing the dielectric effect on the dielectric by electrically bonding or covalently bonding to the first and second electrodes to increase the surface area of the electrodes and thereby increase the current collecting effect. . As a nonmagnetic material, conductive ceramics or organometallic complexes may be used in addition to materials conforming to electrode materials such as Au, Pt, etc., silicon, and copper alloys. As the magnetic material, a soft magnetic material such as iron-cobalt alloy or a material having extremely high magnetic resistance at room temperature due to the Colossal effect (supergiant magnetoresistance effect) such as manganese oxide is selected.
Further, as the material of the fine particles 5a, the same material as the first electrode 4, that is, a conductive metal that is not a magnetic material may be used. In the case of the same material as the first electrode 4 as the material of the fine particles 5a, the surface area of the electrode can be increased by 100 to 500 times. In addition, when a magnetic material is used, the amount of electric energy stored can be further increased by 50 to 100 times due to the magnetic field collecting effect.

In addition, as a form, a nanofiber, a hollow particle, a quantum dot, a micro diameter protrusion structure may be sufficient, and the alternately laminated body of them and a thin film may be sufficient.
Here, the hollow particles refer to particles having microfoam communication holes such as zeolite. The microprojection structure is a structure in which nano-level peaks such as quantum dots are arranged, and can be produced by local corrosion.
Here, a layer formed using nanotechnology is referred to as a nanotechnology formation layer.

  The dielectric layer 6 is composed of nano-level fine particles on the fine particle layer 5 laminated on the first electrode 4. The material of the dielectric layer 6 is made of a material having a high dielectric constant, such as barium titanate. As a form, a hollow particle, a quantum dot, and a micro diameter protrusion structure may be sufficient, and the alternately laminated body of them and a thin film may be sufficient. The dielectric layer 6 is formed by, for example, vacuum deposition, sputtering, pulsed laser deposition (PLD), metal-organic chemical vapor deposition (MOCVD), metal-organic decomposition (metal-organic decomposition). : MOD) and various thin film forming methods such as a liquid phase method (CSD method) such as a sol-gel method. In particular, when the dielectric layer 6 needs to be formed at a low temperature, it is preferable to use plasma CVD, photo CVD, laser CVD, photo CSD, or laser CSD. As shown in FIG. 1, the dielectric layer 6 is formed of a thin film so that each layer is formed as a thin film (the fine particle layer 5 is formed as a fine particle) and is sequentially laminated.

  The fine particle layer 5 is formed on the surface (upper layer) of the dielectric layer 6 while controlling the particle diameter by sputtering or the like, similarly to the first electrode 4. The particle system is set at about 200 to 2000 nm, the number of layers is about 5 and the layers are combined and laminated to a thickness of about 100 nm to 1 μm.

  The second electrode 7 is formed as a thin film in the upper layer of the fine particle layer 5 formed in the upper layer of the dielectric layer 6. The second electrode 7 is not particularly limited as long as it has conductivity, and can be formed of the same material as that of the first electrode 4, but it is not necessary to consider lattice matching, Since it can be formed at room temperature, it can also be formed using a base metal such as iron (Fe) or nickel (Ni) or an alloy such as WSi or MoSi. Further, the thickness of the electrode thin film of the second electrode 7 is not particularly limited as long as it can function as the other electrode of the thin film capacitor, and may be set to about 100 to 10,000 nm, for example.

  The terminal 8 is drawn out from the first electrode 4 and is one terminal for connecting to an input / output circuit (not shown). The first electrode 4 is exposed and partially exposed by masking to draw out the terminal 8. ing. The terminal 9 is drawn from the second electrode 7 and is the other terminal for connecting to an input / output circuit (not shown).

  By forming as described above, the fine particle layer 5 is formed between the first electrode 4 and the dielectric layer 6 and between the second electrode 7 and the dielectric layer 6.

  The electric energy storage device 1 described above charges (stores) electric charges (electric energy) by connecting terminals 8 and 9 to a power supply device (not shown). At this time, if the fine particles 5a of the fine particle layer 5 are made of a magnetic material, current leakage can be prevented by the (super) giant magnetoresistance effect, and more charges can be accumulated in the dielectric layer 6. Then, by changing the terminals 8 and 9 from the power supply device to a load (not shown), the charged electric charge can be discharged and electric energy can be supplied to the load for operation. Therefore, this electrical energy storage device 1 operates as a thin film capacitor.

  According to the present embodiment, the fine particle layer 6 composed of the metal fine particles 5 a is formed between the first electrode 4 and the dielectric layer 6 and between the second electrode 7 and the dielectric layer 6. Therefore, the surface areas of the first electrode 4 and the second electrode 7 can be increased, and the electrical energy that can be stored can be increased. Further, since the fine particles 5a are made of metal, a large voltage and a large current can be taken out, and a large electric energy can be obtained.

  Further, since the fine particles 5a of the fine particle layer 6 are formed of a magnetic material, when a voltage is applied between the first electrode 4 and the second electrode 7, the current collection rate due to the magnetic performance of the fine particles 5a due to the electric field. Can be improved, and more electrical energy can be stored.

  When the fine particles 5a of the fine particle layer 6 described above are formed of a magnetic material, the fine particle layer 6 may be formed in a pre-magnetized state, or may be manufactured as the electric energy forming device 1 to form the electric energy. Before using the device 1, it may be magnetized by applying a magnetic field from the outside. If magnetized in advance, there is no need to magnetize later, and no circuit or device for that purpose is required.

here,
1) Capacitance: 20μF / mm ² can be achieved by making the electrode part into nanoparticles, 1mm height / 100 layers
The possibility of a capacitance of 2000 μF / mm ³ was considered.
This is a calculation of 2000F at 10 cm ³ .
The stored energy is 1/2 x 2000F x 60 ²
= 1KWh = 80Ah (12V conversion)
It becomes. That is, about five times the performance of the lithium battery was proved by the initial verification.
In other words, the dielectric constant can be increased by making the dielectric particles finer, which means that the capacitance is directly improved.
It should be noted that the electrostatic capacity can be further improved by about 5 to 10 times by making the dielectric fine particles, and the storage battery can be further downsized.

  Further, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

<Effect>
As described above, according to this embodiment, a metal fine particle layer composed of metal fine particles is formed between the first electrode and the dielectric layer and between the second electrode and the dielectric layer. As a result, the surface areas of the first electrode and the second electrode can be increased, and thus the electrical energy that can be stored can be increased.
In addition, according to the present embodiment, since the fine particles are formed of metal, a large voltage and a large current can be taken out, and a large electric energy can be obtained.
In addition, according to the present embodiment, the size of the device can be reduced by forming each electrode and the dielectric layer as a thin film and using fine particles having a nano-order particle size.

DESCRIPTION OF SYMBOLS 1 Electric energy storage device 2 Support substrate 3 Buffer layer 4 First electrode 5 Fine particle layer (electrode fine particle surface area expansion layer)
5a Fine particles 6 Dielectric layer 7 Second electrode 8, 9 Terminal

Claims (8)

Formed so as to be sandwiched between a first electrode formed of a conductive material, a second electrode positioned to face the first electrode, and the first electrode and the second electrode An electrical energy storage device comprising:
Between the first electrode and the dielectric layer and between the second electrode and the dielectric layer, fine particles of metal, metal complex or conductive ceramic are formed as an electrode fine particle surface area expanding layer. An electrical energy storage device characterized by.   The electrical energy storage device according to claim 1, wherein the fine particle layer is formed of a nanofiber, a quantum dot, or a nanotechnology forming layer as a quantum protrusion layer.   The electrical energy storage device according to claim 1, wherein a plurality of nanotechnology forming layers are formed.   The electrical energy storage device according to claim 1, wherein the nanotechnology forming layer is formed as a single layer or a plurality of layers, and a thin film metal is incorporated between the layers.   The electrical energy storage device according to claim 1, wherein the nanotechnology forming layer is formed of a magnetic material.   The electrical energy storage device according to claim 5, wherein the nanotechnology forming layer is magnetized. Formed so as to be sandwiched between a first electrode formed of a conductive material, a second electrode positioned to face the first electrode, and the first electrode and the second electrode An electrical energy storage device comprising:
An electrical energy storage device, wherein the dielectric layer is composed of a dielectric constant improving layer formed of a quantum protrusion layer including any one of a thin film, fine particles, and quantum dots.   An electrical energy storage device, wherein the dielectric layer is formed of a composite of a quantum protrusion layer including any one of a thin film, fine particles, and quantum dots.

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