Current collector for secondary batteries

Abstract

To provide a novel electrode, a novel power storage device, an electrode of a large capacity, a power storage device having a large energy density, a power storage device having flexibility, a power storage device having a long life, a highly reliable power storage device, or a power storage device which is small in the worsening in characteristic when an external force is applied thereto repeatedly.SOLUTION: A collector hereof comprises a conductor having a sheet-like shape, of which the thickness is 800 nm or more and 2 0 μm or less, and the area is 25 mm2 or more and 10 m2 or less, in which the conductor has carbon and oxygen; the concentration of the carbon in the conductor is larger than 80 atomic%, and the concentration of the oxygen in the conductor is 2 atomic% or more and 20 atomic% or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an object, a method, or a manufacturing method. Alternatively, the present invention relates to a process, a machi ne, a manufacture, or a composition of matter. In parti cular, one embodiment of the present invention relates to a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, a driving method thereof, or a manufacturing method thereof. In particular, one embodiment of the present invention relates to a power storage device an d a manufacturing method thereof. In particular, one embodiment of the present invention relates to a power storage device an d a method for fabricating the same.

[0002] Note that in this specification, a power storage device refers to all elements and devices having a power storage functio n.

Background Art

[0003] In recent years, various power storage devices such as secondary batteries including lithium-ion secondary batteries, lithium-ion capacitors, and air batteries have been actively developed. In particular, lithium-ion secondary batteries with high output and high energy density have been rapidly spreading along with the development of the semiconductor industry, for use in portable information terminals such as mobile phones, smartphones, and notebook personal computers, electronic devices such as portable music players and digital cameras, or medical equipment, next-generation clean energy vehicles such as hybrid vehicles (HEVs), electric vehicles (EVs), and plug-in hybrid vehicles (PHEVs), and the like, and have become indispensable to the modern information society as a supply source of rechargeable energy. Various power storage devices such as secondary batteries including lithium-ion secondary batteries, lithium-ion capacitors, and air batteries have been actively developed. In particular, lithium-ion secondary batteries with high output and high energy density have been rapidly spreading along with the development of the semiconductor industry, for use in portable information terminals such as mobile phones, smartphones, and notebook personal computers, electronic devices such as portable music players and digital cameras, or medical equipment, next-generation clean energy vehicles such as hybrid vehicles (HEVs), electric vehicles (EVs), and plug-in hybrid vehicles (PHEVs), and the like, and have become indispensable to the modern information society as a supply source of rechargeable energy. Lithium-ion secondary batteries with high output and high energy density have been rapidly spreading along with the development of the semiconductor industry, for use in portable information terminals such as mobile phones, smartphones, and notebook personal computers, electronic devices such as portable music players and digital cameras, or medical equipment, next-generation clean energy vehicles such as hybrid vehicles (HEVs), electric vehicles (EVs), and plug-in hybrid vehicles (PHEVs), and the like, and have become indispensable to the modern information society as a supply source of rechargeable energy. Portable information terminals such as mobile phones, smartphones, and notebook personal computers, electronic devices such as portable music players and digital cameras, or medical equipment , hybrid vehicles (HEVs), electric vehicles (EVs), or plug-in hybrid vehicles (P HEV) and other next-generation clean energy vehicles, the demand for which has expanded rapidly along with the development of the semiconductor industry, and they have become indispensable to the modern information society as a supply source of rechargeable energy. The demand has expanded, and they have become indispensable to the modern information society as a supply source of rechargeable energy. have become indispensable.

[0004] In addition, graphene has attracted significant attention due to its excellent electrical conductivity and the like, and large-scale productio n methods and the like are being explored. As shown in Non-Patent Document 1, graphene oxide (grap The compound obtained by reducing hene oxide (GO) is reduced GO(r It is sometimes referred to as GO, and its physical properties are attracting attention.

[0005] The need for increased capacity in energy storage devices is increasing year by year, and as shown in Patent Document 1, for example, energy storage devices Development is underway to improve the capacity by modifying the position of the electrodes. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2012-009414 [Non-patent literature]

[0007] [Non-Patent Document 1] A. Bagri et al., “Structural evolution during the reduction of chemically derived graphene oxide”, NATURE CHEMISTRY, vol.2, 2010, pp.581-587. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] One aspect of the present invention aims to provide a novel electrode. Or, one aspect of the present invention One of the objectives of this embodiment is to provide a novel energy storage device.

[0009] Alternatively, one aspect of the present invention aims to provide an electrode with a large capacity. One aspect of the present invention aims to provide an energy storage device with high energy density. .

[0010] Alternatively, one aspect of the present invention aims to provide a flexible energy storage device. Alternatively, one aspect of the present invention aims to provide a long-life energy storage device. Furthermore, one aspect of the present invention aims to provide a highly reliable energy storage device. One aspect of the present invention provides an energy storage device that exhibits minimal degradation in characteristics when subjected to repeated external forces. One of the challenges is to provide it.

[0011] Furthermore, the description of these problems does not preclude the existence of other problems. One approach does not necessarily need to solve all of these problems. The title will become clear from the description in the specification, drawings, claims, etc. It is possible to extract other issues from the descriptions in the drawings, claims, etc. [Means for solving the problem]

[0012] One aspect of the present invention has a sheet-like shape and a thickness of 800 nm or more and 20 μm or less. The area is 25mm 2 More than 10m 2 The following is the case, and it contains carbon and oxygen, and the concentration of carbon is , greater than 80 atomic%, and oxygen concentration of 2 atomic% or more at 20 at It is a conductor having a portion that is less than omic%.

[0013] Furthermore, in the above configuration, the conductor has an electrical conductivity of 0.1 S / cm or more. 7 S / c It is preferable that the portion has a value of m or less.

[0014] Furthermore, in the above configuration, it is preferable that the conductor has an aggregate of graphene. Having a graphene aggregate means, for example, having multiple graphenes. Alternatively, it may have multiple graphene compounds.

[0015] Furthermore, in the above configuration, the conductor has multiple layers of graphene ranging from 2 to 100 layers. The longitudinal length of the graphene is preferably between 50 nm and 100 μm. Furthermore, in the above configuration, the interlayer distance of graphene is between 0.335 nm and 0.7 nm. It is preferable to have one.

[0016] Furthermore, in the above configuration, the oxygen concentration of the conductor is measured by X-ray photoelectron spectroscopy. It is preferable that the conductor has a bond between carbon and oxygen. This is preferable.

[0017] Furthermore, in the above configuration, the conductor consists of an epoxy group, a carbonyl group, and a hydroxyl group bonded to carbon. It is preferable to have at least one of the following.

[0018] Furthermore, in the above configuration, the conductor preferably contains 10 ppm to 5% sulfur. It seems so.

[0019] Alternatively, one aspect of the present invention has a positive electrode and a negative electrode, and either the positive electrode or the negative electrode is The device comprises one of the above conductors and a layer having an active material, wherein the layer is at least the conductor. It is an energy storage device that is in contact with one side.

[0020] Alternatively, one aspect of the present invention comprises a positive electrode and a negative electrode, wherein the positive electrode is one of the above. It is an energy storage device that has a conductive material on it.

[0021] Alternatively, one aspect of the present invention comprises a positive electrode and a negative electrode, wherein the positive electrode is one of the above. It has a conductor and a layer, the layer is in contact with at least one surface of the conductor, and the layer is a positive electrode active It is an energy storage device that contains material.

[0022] Furthermore, in the above-mentioned energy storage device, it is preferable that the conductor is laminated with the separator. The electric body is preferably wound up.

[0023] Alternatively, one aspect of the present invention is an electronic device having the energy storage device described above.

[0024] Furthermore, in one aspect of the present invention, a conductor comprises a plurality of graphene compounds arranged so as to partially overlap. It can be fabricated by layering. Here, multiple graphene compounds partially overlap. When these compounds are formed into a single sheet, they are sometimes referred to as graphene compound sheets.

[0025] For example, in one aspect of the present invention, a conductor is constructed by laminating multiple layers of graphene oxide so that they partially overlap. This results in a thickness of 50 nm or more and an area of ​​1 mm². 2 The above sheet was prepared, and the sheet It can be manufactured by performing a reduction treatment. Furthermore, in the conductor, the concentration of carbon The degree of oxygenation is preferably greater than 80 atomic%, and the oxygen concentration is 2 atomic% or higher. Preferably, the atomicity is 20% or less, and the interlayer distance is 0.335 nm or more and 0.7 nm or more. It is preferable that it is less than or equal to m.

[0026] Alternatively, one aspect of the present invention involves stacking multiple graphene oxides so that they partially overlap. This results in a thickness of 50 nm or more and an area of ​​1 mm². 2 The above sheet was prepared, and the sheet This is a method for producing a conductor by performing a reduction treatment. Furthermore, in this conductor, the carbon concentration is 80 Preferably, the oxygen concentration is greater than atomic%, and the oxygen concentration is 2 atomic% or more. Preferably, the tomic percentage is 0.335 nm or less, and the interlayer distance is 0.335 nm or more and 0.7 nm or less. It is preferable that this be the case. [Effects of the Invention]

[0027] According to one aspect of the present invention, a novel electrode can be provided. This allows us to provide more novel energy storage devices.

[0028] Furthermore, according to one aspect of the present invention, an electrode with a large capacity can be provided. In one manifestation, a high-energy-density energy storage device can be provided.

[0029] Furthermore, according to one aspect of the present invention, a flexible energy storage device can be provided. According to one aspect of the present invention, a long-life energy storage device can be provided. In one embodiment, a highly reliable energy storage device can be provided. Furthermore, in one embodiment of the present invention... This makes it possible to provide an energy storage device that exhibits less degradation in characteristics when external forces are repeatedly applied. Cut.

[0030] Furthermore, the description of these effects does not preclude the existence of other effects. One embodiment does not necessarily have to possess all of these effects. Furthermore, other effects may be considered. This will become clear from the description in the specification, drawings, claims, etc., and the specification, drawings It is possible to extract effects other than those mentioned above from the descriptions in the surfaces, claims, etc. [Brief explanation of the drawing]

[0031] [Figure 1] A diagram illustrating a part of a conductor according to one embodiment of the present invention. [Figure 2] A diagram illustrating a conductor according to one embodiment of the present invention. [Figure 3] A diagram illustrating graphene compounds. [Figure 4] A diagram illustrating a part of a conductor according to one embodiment of the present invention. [Figure 5] A diagram illustrating a spray drying device. [Figure 6] A diagram illustrating a portion of the cross-section of an energy storage device. [Figure 7] A diagram illustrating a portion of the cross-section of an energy storage device. [Figure 8] A diagram illustrating a portion of the cross-section of an energy storage device. [Figure 9] A diagram illustrating a portion of the cross-section of an energy storage device. [Figure 10] A diagram illustrating a particle according to one embodiment of the present invention. [Figure 11] A diagram illustrating a portion of the electrode's cross-section. [Figure 12] A diagram illustrating an energy storage device. [Figure 13] A diagram illustrating the method for manufacturing an energy storage device. [Figure 14] A diagram illustrating the method for manufacturing an energy storage device. [Figure 15] A diagram illustrating an energy storage device and a method for manufacturing it. [Figure 16] A diagram illustrating an energy storage device. [Figure 17] A diagram illustrating an energy storage device. [Figure 18] A diagram illustrating a cross-section of an energy storage device. [Figure 19] A diagram illustrating an energy storage device. [Figure 20] A diagram illustrating an energy storage device. [Figure 21] A diagram illustrating a portion of the cross-section of an energy storage device. [Figure 22] A diagram illustrating a portion of the cross-section of an energy storage device. [Figure 23] A diagram illustrating a portion of the cross-section of an energy storage device. [Figure 24] A diagram illustrating an energy storage device. [Figure 25] A diagram illustrating the radius of curvature of a surface. [Figure 26] A diagram illustrating the radius of curvature of film. [Figure 27] A diagram illustrating an example of an energy storage system. [Figure 28] A diagram illustrating an example of an energy storage system. [Figure 29] A diagram illustrating an example of an energy storage system. [Figure 30] A diagram illustrating an example of an electronic device. [Figure 31] A diagram illustrating an example of an electronic device. [Figure 32] A diagram illustrating an example of an electronic device. [Figure 33] A diagram illustrating an example of an electronic device. [Figure 34] A block diagram illustrating one aspect of the present invention. [Figure 35] A conceptual diagram illustrating one aspect of the present invention. [Figure 36] A circuit diagram illustrating one aspect of the present invention. [Figure 37] A circuit diagram illustrating one aspect of the present invention. [Figure 38] A conceptual diagram illustrating one aspect of the present invention. [Figure 39] A block diagram illustrating one aspect of the present invention. [Figure 40] A flowchart illustrating one aspect of the present invention. [Figure 41] A photograph illustrating one aspect of the present invention. [Figure 42] A photograph illustrating one aspect of the present invention. [Figure 43] A photograph illustrating one aspect of the present invention. [Figure 44] A figure showing the XRD evaluation results. [Figure 45] A figure showing the XPS evaluation results. [Figure 46] A figure showing the XPS evaluation results. [Figure 47] A figure showing the XPS evaluation results. [Figure 48] A figure showing the XPS evaluation results. [Figure 49] A figure showing the XRD evaluation results. [Figure 50]A figure showing the FT-IR evaluation results. [Figure 51] A diagram showing the charge and discharge characteristics. [Figure 52] A diagram showing the charge and discharge characteristics. [Figure 53] Optical microscope image. [Figure 54] Optical microscope images and SEM observation results. [Figure 55] Optical microscope image. [Figure 56] SEM observation results. [Figure 57] Cross-sectional TEM observation results. [Figure 58] Cross-sectional TEM observation results. [Figure 59] A photograph showing the experimental results. [Figure 60] A figure showing the XPS evaluation results. [Figure 61] A top view showing one aspect of the present invention. [Modes for carrying out the invention]

[0032] Embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention Not limited to these descriptions, the form and details can be varied in various ways, as any person skilled in the art would know. This is easily understood. Therefore, the present invention is interpreted to be limited to the contents of the embodiments described below. It is not something that should be done.

[0033] In addition, in each figure described herein, the size of each element such as film, layer, substrate, and region is not shown. Thickness and other specifications may be exaggerated for the sake of clarity in individual descriptions. Therefore, they may not necessarily reflect the actual quantities. The size of the constituent elements is not limited to their own size, nor is it limited to the relative size between each constituent element. stomach.

[0034] In this specification, the ordinal numbers such as "1st," "2nd," etc., are used for convenience. This does not indicate the order of processes or the order of layering. For example, "1 The word "no" can be replaced with "the second" or "the third" as appropriate in the explanation. Ordinal numbers described in the specification, etc., and ordinal numbers used to specify one aspect of the present invention They may not match.

[0035] Furthermore, in the configuration of the present invention described herein, etc., the same part or similar function The same reference numerals are used consistently across different drawings for certain parts, and explanations of their repetition are omitted. Furthermore, when referring to parts with similar functions, the hatch pattern is the same, and a special designation is given. There are cases where this does not happen.

[0036] In this specification, both the positive and negative electrodes for an energy storage device are collectively referred to as electrodes. However, in this case, the electrodes shall indicate at least one of the positive and negative electrodes. ru.

[0037] Here, we will explain the charging and discharging rates of an energy storage device. For example, capacity X[ When charging a secondary battery with a constant current, a charging rate of 1C means that charging will be completed in exactly one hour. This refers to the current value I[A] at which charging is complete, and a charging rate of 0.2C is I / 5[A] (that is, This refers to the current value at which charging is completed in exactly 5 hours. Similarly, the discharge rate is 1C and This refers to the current value I[A] at which discharge ends in exactly one hour, and the discharge rate is 0.2C. This refers to I / 5[A] (i.e., the current value at which discharge ends in exactly 5 hours). .

[0038] (Embodiment 1) In this embodiment, a graphene compound according to one aspect of the present invention and a graphene compound according to one aspect of the present invention Conductors containing compound ions will be described.

[0039] Graphene is a material in which carbon atoms are arranged in a single atomic layer and have π bonds between the carbon atoms. A material in which two to 100 layers of graphene are stacked is sometimes called multigraphene. Graphene and multigraphene, for example, along the longitudinal direction or the long axis in a plane. The length is 50 nm to 100 μm or 800 nm to 50 μm.

[0040] In this specification, etc., compounds having graphene or multigraphene as a basic framework The substance is called "graphene compound". It is also called "nd"). Graphene compounds include graphene and multigraphene. nothing.

[0041] The following provides a detailed explanation of graphene compounds.

[0042] Graphene compounds, for example, include graphene or multigraphene, which contain atoms other than carbon. Alternatively, it is a compound modified with an atomic group containing atoms other than carbon. Also, graphene or Multigraphene is modified with carbon-based atomic groups such as alkyl groups and alkylene groups. It may also be a compound. Furthermore, the atomic group that modifies graphene or multigraphene is These may be referred to as substituents, functional groups, or characteristic groups. Hereinafter, modifications are used in this specification. This refers to the formation of graphene, multigraphene, through substitution, addition, or other reactions. Graphene compounds, or graphene oxide (described later), containing atoms other than carbon, or other than carbon. This refers to introducing an atomic group containing atoms of a certain type.

[0043] Furthermore, the front and back surfaces of graphene are modified by different atoms or groups of atoms. This is also good. In addition, in multigraphene, each layer is modified with different atoms or groups of atoms. It's fine if it is done.

[0044] As an example of graphene modified with the above-mentioned atoms or groups of atoms, oxygen or oxygen Examples include graphene or multigraphene modified with functional groups containing oxygen. Examples of functional groups it contains include epoxy groups, carbonyl groups such as carboxyl groups, hydroxyl groups, and Examples include lactol groups. Graphs modified with oxygen or oxygen-containing functional groups. The compound is sometimes called graphene oxide. In this specification, graphene oxide is used. This shall also include multilayer graphene oxide.

[0045] Next, an example of a method for producing graphene oxide will be described. Graphene oxide is produced by the above graph It can be obtained by oxidizing graphene or multigraphene. Alternatively, graphene oxide can be obtained by acid It can be obtained by separating the interlayers of graphite oxide. Graphite oxide is obtained by separating the interlayers of graphite. It can be obtained by oxidation. Here, graphene oxide is further oxidized with the aforementioned atoms or atoms You may modify the word "group".

[0046] Methods for producing graphene oxide include, for example, the Hummers method and Modified Various synthesis methods can be used, such as the Hummers process or the oxidation of graphites.

[0047] For example, the Hummers method and the Modified Hummers method are used for scaly grafts. This is a method of forming graphite oxide by oxidizing graphite such as phyto. In graphite oxide, the carbonyl groups are formed when the graphite is oxidized in places. These are compounds to which functional groups such as carboxyl groups, hydroxyl groups, and lactol groups are attached, as shown in the graph. The crystallinity of the fiber is impaired, and the interlayer distances are increased. Therefore, ultrasonic treatment, etc. This allows for easy separation of the layers, thereby obtaining graphene oxide.

[0048] Here, we will describe an example of a method for producing graphene oxide using the Modified Hummers method. To clarify, add a sulfuric acid solution of potassium permanganate to graphite powder and perform an oxidation reaction. It forms a mixture containing graphite oxide. Graphite oxide is composed of the carbon atoms of graphite. Through oxidation, it acquires functional groups such as epoxy groups, carbonyl groups, carboxyl groups, and hydroxyl groups. Therefore, the interlayer distance of graphene oxide is longer compared to graphite. Next, oxidation By applying ultrasonic vibrations to a mixture containing graphite, the interlayer distance of graphite oxide is increased. The material can be cleaved and graphene oxide separated, and the dispersion containing graphene oxide can also be separated. It can form a liquid.

[0049] By using the above Modified Hummers method to produce graphene oxide, For example, the resulting graphene oxide may contain elements such as sulfur and nitrogen.

[0050] The sulfur concentration in the graphene compound according to one embodiment of the present invention is preferably 5% or less. 3% or less is preferable.

[0051] The graphene compound according to one aspect of the present invention is, for example, 10 ppm or more and 5% or less, or 10 It may contain sulfur in concentrations of 0 ppm to 3%, or 0.1% to 3%.

[0052] The sulfur concentration in the graphene compound can be evaluated using, for example, elemental analysis such as XPS. It can be valued.

[0053] Furthermore, the graphene compound according to one embodiment of the present invention contains, for example, 0.1% to 3% nitrogen. It may happen.

[0054] The compound obtained by reducing graphene oxide is called "RGO (Reduced Graph)". It is sometimes called "ene Oxide". Here, RGO is as shown in Non-Patent Document 1. It is sometimes written as "rGO". Note that RGO is the oxygen contained in graphene oxide. In cases where not all of the oxygen is eliminated, and some oxygen or oxygen-containing atomic groups remain bonded, Yes, there are. For example, RGO is an epoxy group, a carbonyl group such as a carboxyl group, or a hydroxyl group. It may have functional groups such as the following.

[0055] Graphene compounds are formed in the form of a single sheet, with multiple graphene compounds partially overlapping. It may be as follows. Such graphene compounds are sometimes called graphene compound sheets. There is a compatibility. For example, graphene compound sheets have a thickness of 0.33 nm to 10 mm. Preferably, the region is greater than 0.34 nm and less than or equal to 10 μm. Graphene compound A group of atoms other than carbon, a group of atoms containing atoms other than carbon, or a group of atoms such as alkyl groups containing carbon It may be modified with a main group of atoms, etc. Also, the graphene compound sheet has Each of the multiple layers may be modified with different atoms or groups of atoms.

[0056] Graphene compounds include not only six-membered rings composed of carbon, but also five-membered rings composed of carbon, and carbon It may have multi-membered rings of seven or more members composed of elements. Here, in the vicinity of a multi-membered ring of seven or more members This can create regions through which ions can pass. Here, lithium ions are an example of such ions. One example is the on. Alternatively, it is used as an ion of alkali metals other than lithium, or as an electrolyte. Examples include anions and cations, anions and cations present in the electrolyte, and so on. .

[0057] Alternatively, for example, multiple graphene compounds may be aggregated to form a sheet-like structure. Graphene compounds have a planar shape, which allows for surface contact.

[0058] Graphene compounds can have high conductivity even when thin, and graphene formation occurs through surface contact. This can increase the contact area between the compounds, or between the graphene compound and the active material. Therefore, a conductive path can be efficiently formed even with a small amount per unit volume.

[0059] Furthermore, graphene compounds can also be used as insulators. For example, graphene compounds The sheet can be used as a sheet-like insulator. Here, for example, graphene oxide is It may have higher insulating properties compared to unoxidized graphene compounds. Also, the atomic group Modified graphene compounds can have enhanced insulating properties depending on the type of atomic group being modified. It is sometimes possible.

[0060] Figure 3(A) is a schematic diagram illustrating a single layer of graphene. Figure 3(B) shows graphene. Examples of cases where functional groups such as epoxy groups, carboxyl groups, and hydroxyl groups are added are shown. Figure 3(B) is an example, and graphene with added functional groups is not limited to this.

[0061] <Conductor> Figure 2 shows an external view of a conductor 201 according to one embodiment of the present invention. The conductor 201 is preferably in a sheet-like shape.

[0062] The conductor 201 preferably contains a graphene compound.

[0063] Here, the thickness of the conductor 201 is, for example, 0.33 nm to 100 μm, or 50 nm to 100 μm, or 800 nm to 20 μm.

[0064] Further, the area of the conductor 201 is, for example, 1 mm 2 to 100 m 2 , 25 mm 2 to 10 m 2 , 100 mm 2 to 3 m 2 .

[0065] The conductor 201 is described in more detail below. A region 202 indicated by a broken line in Figure 2 shows a part of the cross section of the con ductor 201. Figure 1(A) is an enlarged view of the region 202. Further, Figure 1 (B) is an enlarged view of a region 202a shown in Figure 1(A). The region 202a preferably contains a plurality of gra phene compounds 211, and the plurality of graphene compounds 211 preferably partially overlap . A structure in which a plurality of graphene compounds partially overlap to form a single sheet may be referred to as a graphene compound sheet. It is preferable to use the graphene compound sheet as the conductor 201.

[0066] Here, the length of one side of the graphene compound (also referred to as flake size) is 50 nm to 100 μm, preferably 800 nm to 20 μm.

[0067] ​​​ A graphene compound sheet in which multiple graphene compounds are superimposed, for example, adjacent graphs In some cases, regions where ions can pass through may be created between the ion compounds. Therefore, the graph Graphene compound sheets may have excellent ionic conductivity. Alternatively, graphene compound sheets To may be prone to adsorbing ions.

[0068] Furthermore, graphene compound sheets, in which multiple graphene compounds are layered, are stacked in a planar manner. The graphene compounds can deform when an external force is applied by sliding against each other. It is thought that cracks and other damage may be less likely to occur.

[0069] Here, an example of a top view showing a part of the conductor 201 is shown in Figure 61. Multiple graphenes An example of how compound 211 overlaps is shown. Therefore, the surface of the conductor 201 is graphite. There may be a step corresponding to the thickness of the compound. Also, the surface of the conductor 201 may have a step. There may be an area that is roughly enclosed by the gradient and is flatter than the step, and the area of ​​this region is the graph This may correspond to the area of ​​the compound.

[0070] Furthermore, an example of a different region 202a from that shown in Figure 1(B) is shown in Figures 4(A) and 4(B). .

[0071] The presence of a graphene compound in the conductor 201 makes the conductor 201 flexible and deformable. It can be made into an easy configuration. Also, the conductor 201 has a graphene compound. In some cases, this can increase the mechanical strength of the conductor 201.

[0072] Furthermore, the conductor 201 may contain graphene or multigraphene as a graphene compound. By having this, the conductivity of the conductor 201 can be increased.

[0073] The electrical conductivity of the conductor 201 in one aspect of the present invention is preferably 0.1 S / cm or more. 7 S / cm or less, more preferably 1S / cm or more 10 6 S / cm or less, more preferably 10 S / cm or more 10 6 It is less than or equal to S / cm. Here, the electrical conductivity of conductor 201 is, for example, If the electric body 201 is in sheet form, the terminals are placed against the sheet surface and the measurement is performed using the four-terminal method. It is possible.

[0074] An example of the interlayer distance of the graphene compound 211 in the conductor 201 is shown. The interlayer distance of compound 211 is, for example, between 0.335 nm and 0.7 nm, or 0.34 There are those that are greater than nm and less than or equal to 0.6 nm, or greater than 0.34 nm and less than or equal to 0.5 nm. The wavelength should be greater than 0.34 nm and less than 0.44 nm. Here, the graphene compound... Methods for calculating the interlayer distance in 211 include XRD and TEM.

[0075] In TEM observation, however, it is possible to observe minute areas, for example, areas ranging from a few nanometers to a few micrometers square. To make an inference. In comparison, XRD evaluation assesses a wider range of average information. It is sometimes possible.

[0076] Next, the oxygen content of the conductor 201 can be determined, for example, by XPS (X-ray photoelectron spectroscopy) or ED. It can be evaluated using X, etc. The oxygen content of the conductor 201 is measured by XPS. In that case, preferably 2 to 20 atomic percent of the total conductor 201. The amount is between 2 atomic% and 11 atomic%, more preferably 3 atomic% or more. It is less than 10 atomic%. Also, when conductor 201 was measured by XPS, the carbon content was By analyzing the spectrum of the binding energy corresponding to C1s by waveform separation, C1 For the entire spectrum of s, sp 2 The proportion of the area occupied by the peak suggesting this can be expressed as an area ratio. It can be accumulated. Here, in the conductor 201, sp 2 The proportion of C1s is the total It is preferable that the amount is between 50% and 90% of the spectrum.

[0077] Furthermore, the proportion of carbon in conductor 201 is 80% or more of the total conductor 201. A larger size is preferable. The carbon content should be evaluated using methods such as XPS or EDX. It is possible.

[0078] The oxygen content of the graphene compound 211 in the conductor 201 was measured by XPS. 2 to 20 atomic percent of the total conductor 201, preferably 2 at omic% to 11atomic%, more preferably 3atomic% to 10at It is less than 0. Also, regarding the carbon bonding of graphene compound 211, two carbons The proportion of double bonds is preferably, for example, 50% to 90%. For example, when measured by XPS, the spectrum of the binding energy corresponding to carbon C1s is By separating the waveforms and analyzing them, the sp spectrum of the entire C1s spectrum is obtained. 2 This shows In some cases, the proportion occupied by the inciting peak can be estimated as an area ratio. Alternatively, N With MR 13 When evaluating the spectrum of C, for example, if the chemical shift is between 130 ppm and 14 ppm A peak suggesting a carbon double bond can be observed between 0 ppm and near 0 ppm. It is possible. Also, for example, COC bonds can be found between 50 ppm and 60 ppm, or near that level. The carbon-hydroxyl group bond is maintained between 70 ppm and 80 ppm, or near that level. A peak suggesting this can be observed. 2 Peaks suggesting this include, for example, carbon observed in NMR. The ratio of the area of ​​the peak suggesting a carbon double bond to the area of ​​all peaks indicating a primary bond. It may also be calculated as a sum. For example, all peaks in the range of -50 ppm to 250 ppm. It can also be determined as the ratio of the area of ​​the peak suggesting a carbon double bond to the area of ​​the surrounding area.

[0079] Furthermore, the proportion of carbon in the graphene compound 211 of the conductor 201 is It is preferable that the carbon content is greater than, for example, 80% of the total. The carbon content is, for example, XPS, E It can be evaluated using DX (Digital Transformation), etc.

[0080] <Interlayer compound> Alternatively, the conductor 201 may have molecules or ions between its layers as a graphene compound. Intercalation compounds may be used. If the graphene compound is an intercalation compound, the intercalation Electrical conductivity can change depending on the type of molecule or ion. For example, graphene compounds In some cases, the electrical conductivity of a material can be increased. Also, the size of the molecules and ions between the layers, Depending on the content, the interlayer distance may increase.

[0081] <Method for fabricating conductive materials> As an example, a method for producing a conductor 201 having a graphene compound 211 is described below. ru.

[0082] First, a graphene compound sheet 222 is prepared. The graphene compound sheet 222 is It is manufactured using graphene compounds as raw materials, employing methods such as spray drying and coating. This can be done. Here, as an example, graphene oxide dispersion is used as the raw material, and spray dryer A graphene compound sheet 222 containing graphene oxide is prepared by method I. At least a portion of the graphene oxide in the graphene oxide dispersion is multilayered graphene oxide It's fine to use "en".

[0083] Using graphene oxide dispersion as a raw material, multiple oxides are applied to a plate using the spray-drying method. A graphene film is formed to obtain a graphene compound sheet 222 having graphene oxide. Oh, the spray drying method can be obtained by adjusting, for example, the film formation time and the concentration of the dispersion. In some cases, the film thickness of the graphene compound sheet can be controlled, and in one aspect of the present invention, It is suitable for the production of graphene compound sheets. The obtained graphene compound sheet can be peeled off the plate. It is sufficient if the solvent used in the graphene oxide dispersion is preferably a polar solvent. For example, water or NMP can be used.

[0084] A schematic diagram of the spray drying apparatus 280 is shown in Figure 5(A). The spray drying apparatus 280 is It has a chamber 281 and a nozzle 282. The nozzle 282 has a tube 283. Then the dispersion 284 is supplied. The dispersion 284 is sprayed from the nozzle 282 into the chamber 281. It is supplied in a mist form and dried in the chamber 281. The nozzle 282 is connected to the heater 285. It may be heated further. Here, the heater 285 heats the nozzle out of the chamber 281. The region close to 282, for example, the region enclosed by the dashed line shown in Figure 5(A), is also heated. When graphene oxide dispersion is used as the powder 284, the supply from the graphene oxide dispersion A portion of the graphene oxide is recovered as a powder in the recovery container 286 via the chamber 281. A portion of it is then deposited as a graphene compound sheet 222 on the wall surface of the chamber 281. Here, the atmosphere inside chamber 281 is influenced by the path shown by arrow 288, such as the aspirator. It may be attracted by suction.

[0085] Alternatively, a substrate may be placed inside the chamber 281, and a graphene compound sheet may be placed on the substrate. A film may be formed. The substrate may be flat or curved. Also, the substrate may be in the direction of the nozzle 282. They may be installed parallel to each other, or they may be installed at a certain angle. For example, nozzle 282 It may also be installed vertically. In Figure 5(B), the substrate 287 is installed vertically on the nozzle 282, and the substrate An example of depositing a graphene compound sheet 222 is shown above. Here, for example, the nozzle 282 is to the left When film deposition is performed while moving to the right, the uniformity of the film thickness within the plane can be improved. Alternatively, the substrate 287 may be moved left or right. Alternatively, the nozzle 282 and substrate 2 You can also run both 87s.

[0086] The resulting graphene compound sheet 222, for example, when evaluated by XRD, shows a reading of 7° It is preferable to have a peak in the range of 10° or less. Here, a peak is, for example... This is the maximum value. Alternatively, a peak is, for example, a local maximum value.

[0087] Here, the interlayer distance of the graphene compound sheet 222 is, for example, greater than 0.8 nm. The size is less than or equal to nm, or between 0.85 nm and 1.3 nm.

[0088] In TEM observation, however, it is possible to observe minute areas, for example, areas ranging from a few nanometers to a few micrometers square. To make an assessment. In contrast, XRD evaluation uses, for example, a wider range of average information. It can be evaluated.

[0089] The interlayer distance observed by TEM is smaller than the interlayer distance calculated from XRD evaluation. In some cases, this may occur. For example, in graphene compound sheet 222, observation by TEM was The interlayer distance may be less than 0.5 nm.

[0090] Next, the graphene compound sheet 222 is subjected to a reduction treatment to obtain the conductor 201. Conductor 201 can also be called a graphene compound sheet. Graphene compound sheet 2 By reducing 22, the graphene oxide contained in the graphene compound sheet 222 is It can be reduced and its conductivity can be increased. Therefore, conductor 201 is a graphene compound. It has higher conductivity than 222. Through the above process, a sheet-like conductor 201 is obtained. Example For example, the sheet-like conductor 201 may be processed by cutting or other means to form a strip-shaped conductor 201.

[0091] Reduction treatment methods include chemical reduction, which utilizes a reaction with a reducing agent, and heat treatment. Thermal reduction and other methods can be used.

[0092] Let's explain chemical reduction. Examples of reducing agents include ascorbic acid, hydrazine, and dimethyl Hydrazine, hydroquinone, sodium borohydride (NaBH4), aluminum hydride Lithium (LiAlH4), N,N-diethylhydroxylamine, or their derivatives The body can be used. For example, ascorbic acid and hydroquinone can be used with hydrazine and Compared to sodium borohydride, it has weaker reducing power, making it safer and easier to use industrially. It is preferable in that context.

[0093] A polar solvent can be used as the solvent, as long as it can dissolve the reducing agent. However, it is not limited to materials. For example, water, methanol, ethanol, acetone, tetrahydrogen Lofran (THF), Dimethylformamide (DMF), 1-Methyl-2-pyrrolidone ( NMP) and dimethyl sulfoxide (DMSO), ethylene glycol, diethylene glycol One or more of lycolin or glycerin, or a mixture of two or more, can be used.

[0094] A reducing solution containing a reducing agent and solvent is a mixture of ethanol and ascorbic acid. Alternatively, a mixture of water, ascorbic acid, and lithium hydroxide can be used.

[0095] Graphene oxide undergoes protonation by ascorbic acid. Subsequently, H2O is removed. By separating them, graphene oxide is reduced.

[0096] The reduction temperature for chemical reduction is, for example, above room temperature and below 100°C, more preferably between 40°C and 70°C. The following applies. Furthermore, the processing time can be between 3 minutes and 10 hours.

[0097] Washing may be performed after the reduction treatment. Washing can be performed using, for example, a solvent included in the reducing solution. It is best to use a solution. Alternatively, the solvent contained in the reducing solution may be the same solution. Different solutions may be used. After washing, drying may be performed.

[0098] Next, we will explain thermal reduction. The thermal reduction process is, for example, between 50°C and 500°C, Preferably, the process should be carried out at a temperature of 120°C to 400°C for 1 hour to 48 hours. The process may be carried out under reduced pressure (vacuum) or a reducing atmosphere, or at atmospheric pressure. As the gas, air may be used, or nitrogen or other inert gases may be used.

[0099] Here, the conductor 201 obtained after reduction, for example, when evaluated by XRD, yields a value of 21° It is preferable that the peak is present in the range of 27° or less.

[0100] (Embodiment 2) This embodiment shows an example in which a conductor 201 according to one aspect of the present invention is applied to an electrode. Conductor Compound 201 contains graphene compound 211.

[0101] In one embodiment of the present invention, it is preferable that the conductor 201 functions as an active material for an electrode. In other words, it is preferable that the conductor 201 contributes to charging and discharging reactions. For example, in the present invention By using the conductor 201 of one embodiment as an electrode in an energy storage device, the conductor 201 is reduced to It may contribute to the original reaction. Here, a redox reaction refers, for example, to the transfer of electrons. As a concrete example, a redox reaction is a reaction between ions, such as anions or cations. This refers to the transfer of electrons through a reaction.

[0102] Alternatively, the conductor 201 according to one aspect of the present invention may have an electrical double layer formed on its surface. Therefore, it may be possible to use it as an electrode for a capacitor. Conductor according to one aspect of the present invention For example, it may have a larger surface area compared to graphite, etc. Electrodes with a large surface area By using this method, the capacity of the energy storage device can be increased.

[0103] Furthermore, the conductor 201 may be used as a current collector for the electrode. For example, in one embodiment of the present invention The electrode may have a conductor 201 and an active material other than the conductor 201. By using it as a current collector, it becomes possible to make the current collector thinner and lighter the electrodes. It may be possible in some cases. Also, the electrodes may be prone to deformation.

[0104] An example of an electrode is described below.

[0105] <Example of electrodes 1> The inventors have found that when the conductor 201 according to one aspect of the present invention is used as an electrode in an energy storage device, high We found that a large capacity could be obtained. As will be described in detail in later examples, the conductor 201 When used as an electrode, it is possible to obtain a discharge capacity of approximately 100 mAh / g. Understood. Here, the discharge capacity of the conductor 201 is, for example, preferably 10 mAh / g or more. Preferably, it is 40mAh / g or higher.

[0106] An example of using a conductor 201 according to one aspect of the present invention as an electrode in an energy storage device is shown. The conductor 201 is G It contains graphene compound 211. Regarding graphene compound 211, the previous embodiment is It can be referenced.

[0107] The energy storage device 100 shown in Figure 6(A) consists of a conductor 201, a separator 107, and an electrode 15 It has 1 and . The separator 107 is sandwiched between the conductor 201 and the electrode 151. The electrical device 100 preferably has an electrolyte (not shown) between the conductor 201 and the electrode 151. It seems so. Also, as shown in Figure 6(B), the energy storage device 100 has a separator 107 in between. There may be multiple pairs of opposing electrodes 151 and conductors 201. For example, the electrodes 151 are It comprises a current collector and a first layer on the current collector. Here, the first layer has an active material. This is preferable. Details of the components of electrode 151 will be described later.

[0108] The energy storage device 100 shown in Figure 7(A) comprises a conductor 201, an electrolyte 158, and an electrode 151. , has. The electrolyte 158 is sandwiched between the conductor 201 and the electrode 151. Electrolyte 158 and For example, it is preferable to use a solid electrolyte. The electrolyte 158 consists of a conductor 201 and an electrode 1 It is in contact with both sides of 51. Also, as shown in Figure 7(B), the energy storage device 100 has an electrolyte 158 There may be multiple sets of electrodes 151 and conductors 201 facing each other across the electrode.

[0109] Here, by using a graphene compound sheet as the conductor 201, the current collector and active It can serve as both a material and an active material. Therefore, compared to the case where an active material is placed on a current collector such as metal foil, This allows for an increase in the capacity of the energy storage device.

[0110] <Method for fabricating conductive materials> Here, for example, a sheet-shaped or strip-shaped separator is used as the separator 107, The conductive body 201 may be formed on at least one of the surfaces of the separator 107. For example, methods such as spray drying and coating can be used to form 201. The application method will be described later.

[0111] The electrolyte and separator will be described in detail in a later embodiment. You should use "ta".

[0112] <Example of electrodes 2> Next, an electric having a conductor 201 according to one aspect of the present invention and an active material different from the conductor 201. shows an example of an electrode. An electrode 101 shown in FIG. 8 includes a conductor 201 and a layer 102. The layer 102 contains an active material 103. The layer 102 is preferably provided on at least one surface of the conductor 201. In FIG. 8(A), the layer 102 is provided on one surface of the conductor 201. In FIG. 8(B), the layer 102 is provided on both surfaces of the conductor 201.

[0113] A power storage device 100 shown in FIG. 9(A) includes an electrode 101, an electrode 151, and a separator 107 . As shown in FIG. 9(B), the power storage device 100 may include a plurality of pairs of the electrode 101 and the electrode 151 that face each other with the separator 107 interposed therebetween. The power storage device 100 shown in FIG. 9 preferably has an electrolytic solution (not shown) between the electrode 101 and the electrode 151. Alternatively, the power storage device 100 may include an electrolyte 158 between the electrode 101 and the electrode 151. The layer 102 may further contain a conductive aid, a binder, or the like.

[0114] When the electrode 101 is a positive electrode, the layer 102 preferably contains a positive electrode active material as the active material 103.

[0115] When the electrode 101 is a negative electrode, the layer 102 preferably contains a negative electrode active material as the active material 103. When the electrode 101 is a positive electrode, the electrode 151 preferably contains a negative electrode active material as its active material, and when the electrode 101 is a negative electrode, the electrode 151 preferably contains a positive electrode active material as its active material. The electrode 151 includes, for example, a current collector and a first layer over the current collector.

[0116] Here, the first layer preferably contains an active material. The first layer may further contain a conductive aid, a binder, or the like.

[0117] ​​​​good.

[0118] The current collector of electrode 151 may be stainless steel, gold, platinum, aluminum, titanium, etc. Highly conductive materials such as metals and their alloys can be used. When used as the positive electrode, it is preferable that it does not dissolve at the positive electrode potential. Also, when the current collector is used as the negative electrode... If present, it is preferable that it does not form an alloy with carrier ions such as lithium. Elements that improve heat resistance, such as condensate, titanium, neodymium, scandium, and molybdenum, are added. The added aluminum alloy can be used. Furthermore, it reacts with silicon to form silicide. It may be formed with a metallic element that reacts with silicon to form silicides. The materials used are zirconium, titanium, hafnium, vanadium, niobium, tantalum, and chlorofluorocarbon. Examples include molybdenum, tungsten, cobalt, nickel, etc. Current collectors are foil-shaped, plate-shaped ( Appropriate shapes such as sheet, mesh, perforated metal, and expanded metal can be used. This can be done. It is best to use a current collector with a thickness of 5 μm to 30 μm. Also, A conductor 201 may be used as the current collector of pole 151.

[0119] For example, the positive electrode active material may have an olivine-type crystal structure, a layered rock salt-type crystal structure, or a spi A composite oxide having a Nell-type crystal structure can be used.

[0120] As positive electrode active materials, LiFeO2, LiCoO2, LiNiO2, LiMn2O4, V Compounds such as 2O5, Cr2O5, and MnO2 can be used. In particular, LiCoO2 It has a large capacity, is more stable in the atmosphere than LiNiO2, and is more stable than LiNiO2. It is preferable because it has advantages such as being thermally stable. Also, LiMn2O4 and other materials A lithium-containing material having a spinel-type crystal structure containing cinnabar, with a small amount of lithium nickelate added. Um (LiNiO2 and LiNi 1-x M x When O2 (M=Co, Al, etc.) is mixed, This is preferable because it can improve the characteristics of secondary batteries using this method.

[0121] For example, the positive electrode active material has an average particle diameter of primary particles that is between 5 nm and 50 μm. Preferably, the specific surface area is 100 nm or more and more preferably 500 nm or less. m 2 / g or more 15m 2 It is preferable that it be less than or equal to / g. Also, the average particle size of the secondary particles is The particle size is preferably between 5 μm and 50 μm. The average particle size is measured using SEM (Scanning Electron Microscope). Observation by microscope or TEM, or by particle size distribution analyzer using laser diffraction / scattering, etc. It can be measured in this way. Furthermore, the specific surface area can be measured by the gas adsorption method.

[0122] Furthermore, as a positive electrode active material, the composition formula is Li a Mn b M c O d Lithium A manganese composite oxide can be used. Here, element M is other than lithium or manganese. It is preferable to use a selected metal element, or silicon, phosphorus, or nickel. This is even more preferable. Also, when measuring the entire particle of lithium manganese composite oxide, When the voltage <a / (b+c)<2、かつc>is 0, and 0.26≦(b+c) / d<0.5 It is preferable to satisfy this condition. Furthermore, in order to achieve high capacity, the crystal structure in the surface and the center is ​, a lithium-manganese composite oxide having regions differing in crystal orientation or oxygen content is preferable. In order to obtain such a lithium-manganese composite oxide, for example, it is preferable that 1.6≦ a≦1.848, 0.19≦c / b≦0.935, and 2.5≦d≦3 . Furthermore, Li 1.68 Mn 0.8062 Ni 0.318 It is particularly preferable to use a lithium-manganese composite oxide represented by the composition formula of O3. In this specification and the like, Li It is particularly preferable to use a lithium-manganese composite oxide represented by the composition formula of O3. In this specification and the like, Li 1. 68 Mn 0.8062 Ni 0.318 The lithium-manganese composite represented by the composition formula of O3 The oxide refers to a lithium-manganese composite oxide formed by setting the molar ratio of the raw materials to Li2CO3:MnCO3:NiO=0 .84:0.8062:0.318 Therefore, the lithium-manganese composite oxide is represented by the composition formula Li 1.68 Mn 0.80 62 Ni 0.318 O3, but the composition may deviate from this range.

[0123] The composition of metals, silicon, phosphorus and the like in the entire particles of the lithium-manganese composite oxide can be measured using, for example, ICP-MS (inductively coupled plasma mass spectrometer). Also The composition of metals, silicon, phosphorus and the like in the entire particles of the lithium-manganese composite oxide can be measured using, for example, ICP-MS (inductively coupled plasma mass spectrometer). Also The oxygen composition in the entire particles of the lithium-manganese composite oxide can be measured using, for example, EDX (energy dispersive X-ray analysis method). In addition, by using valence evaluation of fusion gas analysis and XAFS (X-ray absorption fine structure) analysis in combination with ICP-MS analysis The oxygen composition in the entire particles of the lithium-manganese composite oxide can be measured using, for example, EDX (energy dispersive X-ray analysis method). In addition, by using valence evaluation of fusion gas analysis and XAFS (X-ray absorption fine structure) analysis in combination with ICP-MS analysis It can be determined. Note that the lithium-manganese composite oxide means an oxide containing at least lithium and manganese It can be determined. Note that the lithium-manganese composite oxide means an oxide containing at least lithium and manganese This refers to oxides containing chromium, cobalt, aluminum, nickel, iron, magnesium, Molybdenum, zinc, indium, gallium, copper, titanium, niobium, silicon, and phosphorus It may contain at least one element selected from the group consisting of the following:

[0124] Lithium manganese composite oxide having regions with different crystal structure, crystal orientation, or oxygen content An example of a cross-sectional view of a particle is shown in Figure 10.

[0125] As shown in Figure 10(A), it has regions with different crystal structures, crystal orientations, or oxygen content. The lithium manganese composite oxide has region 331, region 332, and region 333. This is preferable. Region 332 is in contact with at least a portion of the outside of region 331. Here, outside The side indicates that it is closer to the surface of the particle. Also, region 333 is lithium manganese composite It is preferable that the particles having oxides have a region that coincides with the surface.

[0126] Furthermore, as shown in Figure 10(B), region 331 has an area that is not covered by region 332. This is also possible. Furthermore, region 332 may have regions not covered by region 333. Also, for example... For example, region 331 may have a region adjacent to region 333. Also, region 331 may have a region adjacent to region 3 There may be regions that are not covered by either region 32 or region 333.

[0127] Region 332 preferably has a different composition from region 331.

[0128] For example, the composition of region 331 and region 332 can be measured separately, and region 331 can be found to be lithium, man. Region 332 contains lithium, manganese, element M, and oxygen. The atomic ratio of lithium, manganese, element M, and oxygen in region 331 is a1:b1: Represented as c1:d1, this is the atomic ratio of lithium, manganese, element M, and oxygen in region 332. This section explains the case where the region is represented as a2:b2:c2:d2. Note that region 331 and region 3 Each of the 32 compositions was determined, for example, by EDX (energy) analysis using TEM (transmission electron microscope). - It can be measured by dispersive X-ray spectroscopy. In measurements using EDX, lithium compounds Measurement of composition can be difficult. Therefore, the difference in composition between region 331 and region 332 is described below. Next, we will discuss elements other than lithium. Here, d1 / (b1+c1) is 2.2 or greater. Preferably, it is 2.3 or higher, more preferably 2.35 or higher and 3 or lower. Furthermore, it is preferable that d2 / (b2+c2) is less than 2.2, and 2.1 It is more preferable that it be less than 1.1, and even more preferable that it be between 1.1 and 1.9. Even in this case, the entire lithium manganese composite oxide particle including regions 331 and 332 The composition is preferably such that the aforementioned 0.26 ≤ (b+c) / d < 0.5 is satisfied.

[0129] Furthermore, the manganese in region 332 has a different valency than the manganese in region 331. It is also possible to do so. Furthermore, the element M present in region 332 has a different value than the element M present in region 331. It may have a number.

[0130] More specifically, region 331 is a lithium manganese composite having a layered rock salt-type crystalline structure. It is preferable that it be an oxide. Also, region 332 is lithium having a spinel-type crystal structure It is preferable that it be a manganese composite oxide.

[0131] Here, if there is a spatial distribution of the composition of each region or the valence of elements, for example, multiple locations The composition and valency of each region are evaluated, their average values ​​are calculated, and the composition and valency of that region are also evaluated. good.

[0132] Furthermore, a transition layer may be present between region 332 and region 331. Here, the transition layer is: For example, a region in which the composition changes continuously or stepwise. Alternatively, a transition layer is a crystal A transition layer is a region in which the structure changes continuously or stepwise. This is a region where the constant changes continuously or stepwise. Or, the second region and the first region. A mixed layer may be present between them. Here, the mixed layer is, for example, two layers having different crystal orientations. This refers to the case where the above crystals are mixed. Alternatively, a mixed layer may be, for example, a layer having different crystal structures. This refers to a case where two or more crystals are mixed. Alternatively, a mixed layer is, for example, a layer having different compositions. This refers to a case where two or more crystals are mixed.

[0133] Region 333 can be made of carbon or a metallic compound. Here, as a metallic compound, For example, cobalt, aluminum, nickel, iron, manganese, titanium, zinc, lithium, etc. Examples of metal compounds include oxides and fluorides of these metals. They may have, etc.

[0134] Region 333 is particularly preferably composed of carbon, as carbon has high conductivity. Therefore, by using carbon-coated particles as electrodes in an energy storage device, for example, the resistance of the electrodes can be reduced. It can be made lower. Furthermore, region 333 preferably contains a graphene compound. By using a graphene compound in region 333, lithium manganese composite oxide particles It can be efficiently coated. Graphene compounds will be discussed later. Also, region 3 More specifically, 33 may have graphene, or it may have graphene oxide. Furthermore, graphene obtained by reducing graphene oxide is used as the graphene. This is preferable. Graphene has excellent electrical properties, such as high conductivity, and high flexibility. It also possesses excellent physical properties, including high mechanical strength. Region 333 contains oxide When reduction is performed using lafen, the region 332 adjacent to region 333 is oxidized. be.

[0135] Region 333 contains a graphene compound, which allows the lithium manganese composite oxide to be used as the cathode. The cycle characteristics of the secondary battery using this material can be improved.

[0136] The film thickness in region 333 is preferably 0.4 nm or more and 40 nm or less.

[0137] Furthermore, lithium manganese composite oxides, for example, have an average particle diameter of 5 nm or more for primary particles. It is preferable that the wavelength is 50 μm or less, and more preferably between 100 nm and 500 nm. It seems so. Also, the specific surface area is 5m². 2 / g or more 15m 2 It is preferable that it be less than or equal to / g. The average particle size of the secondary particles is preferably between 5 μm and 50 μm.

[0138] For example, carbon-based materials or alloy-based materials can be used as the negative electrode active material.

[0139] Examples of carbon-based materials include graphite, easily graphitizable carbon (soft carbon), and poorly graphitizable carbon (hard carbon). Using carbon fiber, carbon nanotubes, graphene, carbon black, etc. stomach.

[0140] Examples of graphite include artificial graphite and natural graphite. For example, meso Examples include carbon microbeads (MCMB), coke-based artificial graphite, and pitch-based artificial graphite. Here, spheroidal graphite, which has a spherical shape, can be used as artificial graphite. For example, MCMB may have a spherical shape, which is preferable. Also, the surface of MCMB Reducing the product is relatively easy and sometimes preferable. Examples of natural graphite include Examples include flaky graphite and spheroidized natural graphite.

[0141] Graphite is formed when lithium ions are inserted into graphite (during the formation of lithium-graphite intercalation compounds). It exhibits a potential as low as lithium metal (0.1V to 0.3V vs. Li / Li + This allows lithium-ion secondary batteries to exhibit a high operating voltage. Furthermore, Graphite has a relatively high capacity per unit volume, relatively small volume expansion, and is inexpensive. It is preferable because it has advantages such as higher safety compared to lithium metal.

[0142] As a negative electrode active material, the charge-discharge reaction is carried out by alloying and dealloying reactions with lithium. Any possible element can be used. For example, silicon, tin, gallium, aluminum, Germanium, lead, antimony, bismuth, silver, zinc, cadmium, indium, etc. Materials containing at least one of these elements can be used. Such elements have a capacity compared to carbon. Larger, and especially silicon, has a high theoretical capacity of 4200 mAh / g. Therefore, the negative electrode active material Silicon is preferred. Compounds containing these elements may also be used. For example, SiO, Mg2Si, Mg2Ge, SnO, SnO2, Mg2Sn, SnS2, V2Sn3, FeSn2, CoSn2, Ni3Sn2, Cu6Sn5, Ag3Sn, Ag 3Sb, Ni2MnSb, CeSb3, LaSn3, La3Co2Sn7, CoSb3, Examples include InSb and SbSn. Here, charging and discharging occur through alloying and dealloying reactions with lithium. In some cases, elements capable of carrying out reactions, and compounds containing such elements, are referred to as alloying materials. be.

[0143] Furthermore, in this specification, SiO refers to, for example, silicon monoxide. Or SiO refers to, It can also be expressed as SiOx. Here, it is preferable that x has a value in one neighborhood. For example, x Preferably, it is between 0.2 and 1.5, and more preferably between 0.3 and 1.2.

[0144] Furthermore, titanium dioxide (TiO2) and lithium titanium oxide (Li4) are used as negative electrode active materials. Ti5O 12 ), lithium-graphite intercalation compound (Li x C6), niobium pentoxide (Nb2O5) ), use oxides such as tungsten oxide (WO2) and molybdenum oxide (MoO2). It is possible.

[0145] Furthermore, as the negative electrode active material, a Li3N type structure, which is a lithium and transition metal binitride, is also used. TsuLi 3-x M x N (M = Co, Ni, Cu) can be used. For example, Li 2. 6Co 0.4 The N3 has a large charge / discharge capacity (900mAh / g, 1890mAh / cm²). 3 )of This is preferable.

[0146] When using a lithium-transition metal binitride, lithium ions are included in the negative electrode active material. In combination with materials such as V2O5 and Cr3O8 that do not contain lithium ions as the positive electrode active material. It is preferable that this be done. Furthermore, when using a material containing lithium ions as the positive electrode active material, Also, by pre-desorbing the lithium ions contained in the positive electrode active material, the negative electrode active material and Therefore, a lithium-transition metal composite can be used.

[0147] Furthermore, materials that undergo a conversion reaction can also be used as the negative electrode active material. For example For example, lithium, such as cobalt oxide (CoO), nickel oxide (NiO), and iron oxide (FeO). Transition metal oxides that do not form alloys with mu may be used as the negative electrode active material. Conversion reaction Materials that produce this include Fe2O3, CuO, Cu2O, RuO2, and Cr2O3. Oxides such as CoS 0.89 , sulfides such as NiS and CuS, Zn3N2, Cu3N, Ge Nitrides such as 3N4, phosphides such as NiP2, FeP2, CoP3, FeF3, BiF3, etc. This also occurs with fluorides.

[0148] The negative electrode active material is preferable because a lower reaction potential allows for a higher voltage in the energy storage device. On the other hand, when the potential is low, the reducing power of the electrolyte also increases, so for example, when used in the electrolyte... Organic solvents may be reduced and decomposed. A potential window is defined as the range of potentials within which the electrolyte does not undergo electrolysis. This is called the potential window. Originally, the negative electrode's electrode potential is the same as that of the electrolyte. It needs to be within the potential window, for example, lithium-ion secondary batteries and lithium-ion capacitors Many of the active materials used in the negative electrode of a device have a potential that exceeds the potential window of almost all electrolytes. In particular, materials with low reaction potentials, such as graphite and silicon, offer the advantage of being able to increase the voltage of energy storage devices. On the other hand, there is the problem that the electrolyte is more prone to reductive decomposition.

[0149] Furthermore, the negative electrode active material is pre-loaded with carrier ions such as lithium. That's good too.

[0150] Furthermore, electrodes 101 and 151 may have a conductive additive. Examples of conductive additives include For example, carbon materials, metallic materials, or conductive ceramic materials can be used. A fibrous material may be used as a conductive additive. Content of the conductive additive relative to the total amount of the active material layer. Preferably, the amount is 1 wt% to 10 wt%, and more preferably 1 wt% to 5 wt%. .

[0151] Conductive additives can be used to form an electrical conduction network within electrodes. This allows the electrical conduction pathway between the positive electrode active materials to be maintained. By adding auxiliary agents, it is possible to create an active material layer with high electrical conductivity.

[0152] Examples of conductive additives include natural graphite, artificial graphite such as mesocarbon microbeads, and carbon. Fibers can be used. For example, mesophase pitch carbon fibers can be used. Carbon fibers such as fiber and isotropic pitch carbon fibers can be used. Carbon nanofibers and carbon nanotubes can be used. Notubes can be fabricated, for example, by vapor phase growth. Also, as a conductive additive, For example, carbon black (acetylene black (AB), etc.), graphite particles. Carbon materials such as ions, graphene, and fullerenes can be used. Also, for example, copper, Metal powders and fibers such as nickel, aluminum, silver, and gold, and conductive ceramic materials, etc. You can use it.

[0153] Furthermore, graphene compounds may be used as conductive additives.

[0154] Graphene compounds possess excellent electrical properties, including high conductivity, and high flexibility. It may possess excellent physical properties such as high mechanical strength. The compound has a planar shape. The graphene compound enables surface contact with low contact resistance. Furthermore, even thin materials can have very high conductivity, allowing for efficient use within the active material layer in small quantities. A conductive path can be formed. Therefore, graphene compounds are used as conductive additives. This is preferable because it increases the contact area between the active material and the conductive additive. Furthermore, it is preferable because it can reduce electrical resistance. Here, as a graphene compound For example, it is particularly preferable to use graphene, multigraphene, or RGO.

[0155] When using active materials with a small average particle size, for example, active materials with a particle size of 1 μm or less, the specific table of the active material The surface area is large, and more conductive paths are needed to connect the active materials. In such cases, Using graphene compounds that can efficiently form conductive paths even in small quantities is possible. , particularly preferable.

[0156] The following is an example of the case where a graphene compound is used as a conductive additive in layer 102. An example of surface configuration will be explained.

[0157] Figure 11(A) shows a longitudinal cross-section of layer 102. Layer 102 consists of granular active material 103 and a guide It contains graphene compound 321 as an electrolytic agent and binder 104. Here, graphene For example, graphene or multigraphene can be used as compound 321. Preferably, the graphene compound 321 has a sheet-like shape. Compound 321 is a combination of multiple multigraphenes, or / or multiple graphenes that are partially composed of multiple graphenes. It may be in the form of overlapping sheets. Figure 11(B) shows the same as in Figure 11(A) enclosed by a dashed line. This shows an enlarged view of the region.

[0158] In the longitudinal section of layer 102, as shown in Figure 11(A), the interior of layer 102 is roughly The graphene compound 321 is dispersed almost uniformly in a sheet-like form. In Figure 11(A), the graph Compound 321 is schematically represented by a thick line, but in reality, the thickness of the single or multilayer carbon molecules is different. It is a thin film having multiple graphene compounds 321 and multiple granular active materials 103. In a manner that envelops, covers, or adheres to the surface of multiple granular active materials 103 Because they are formed, they are in surface contact with each other.

[0159] Here, multiple graphene compounds bond together to form a network of graphene compounds. Forming a material sheet (hereinafter referred to as graphene compound net or graphene net) This is possible. When the active material is covered with a graphene net, the graphene net interacts with the active material. It can also function as a binder to hold them together. Therefore, the amount of binder can be reduced. Because it is possible or not to use, the active ingredients in the electrode volume and electrode weight The ratio of quality can be improved. In other words, the capacity of the energy storage device can be increased. ru.

[0160] Here, graphene oxide is used as graphene compound 321 and mixed with the active material to form layer 1 It is preferable to form a layer that becomes O2 and then reduce it. By using graphene oxide, which has extremely high dispersibility in a solvent, graphene compounds 321 can be dispersed approximately uniformly within layer 102. To remove the solvent from the dispersion medium containing graphene oxide and reduce the graphene oxide, The graphene compound 321 remaining in layer 102 partially overlaps and is in surface contact with each other to an extent that The dispersion allows for the formation of three-dimensional conductive paths. The reduction of the ferrite may be carried out, for example, by heat treatment or by using a reducing agent.

[0161] Therefore, unlike granular conductive additives such as acetylene black that make point contact with the active material, the graph Since compound 321 enables surface contact with low contact resistance, it is not a typical conductive additive. This method improves the electrical conductivity between granular active material 103 and graphene compound 321 using a smaller amount. This is possible. Therefore, the ratio of the active material 103 in layer 102 can be increased. This allows for an increase in the discharge capacity of the energy storage device.

[0162] Furthermore, electrodes 101 and 151 may have a binder. For example, a binder may be s Thiene-butadiene rubber (SBR), styrene-isoprene-styrene rubber, acrylon Tolyl-butadiene rubber, butadiene rubber, ethylene-propylene-diene copolymer, etc. It is preferable to use a rubber material. Furthermore, fluororubber can be used as a binder. ru.

[0163] Furthermore, it is preferable to use a water-soluble polymer as the binder. For example, polysaccharides can be used as the derivative. Cellulose (CMC), methylcellulose, ethylcellulose, hydroxypropylcellulose Cellulose derivatives such as lurose, diacetylcellulose, and regenerated cellulose, as well as starch, etc. These can be used. Furthermore, these water-soluble polymers can be used in combination with the aforementioned rubber materials. It would be even better if they were there.

[0164] Alternatively, as a binder, polystyrene, polymethyl acrylate, polymethacrylate Chill (PMMA), sodium polyacrylate, polyvinyl alcohol (PVA), poly Ethylene oxide (PEO), polypropylene oxide, polyimide, polyvinyl chloride, Polytetrafluoroethylene, polyethylene, polypropylene, isobutylene, polyethylene Lenterephthalate, nylon, polyvinylidene fluoride (PVdF), polyacrylonite Lyl (PAN), polyvinyl chloride, ethylene propylene diene polymer, polyacetic acid It is preferable to use materials such as vinyl or nitrocellulose.

[0165] Multiple binding agents may be used in combination from the above options.

[0166] For example, a material with particularly excellent viscosity-modifying properties may be used in combination with other materials. For example, rubber materials have excellent adhesive and elastic properties, but when mixed with a solvent, it is difficult to adjust their viscosity. In such cases, for example, mixing with a material that has particularly excellent viscosity-modifying effects may be necessary. This is preferable. As a material with particularly excellent viscosity adjustment effect, for example, a water-soluble polymer can be used. Good. Also, as water-soluble polymers that are particularly excellent in viscosity adjustment, the aforementioned polysaccharides, for example, Boxymethylcellulose (CMC), methylcellulose, ethylcellulose, hydrox Cellulose inducers such as cypropylcellulose, diacetylcellulose, and regenerated cellulose Conductors and starch can be used.

[0167] Furthermore, cellulose derivatives such as carboxymethylcellulose are, for example, carboxymethyl Solubility increases when cellulose is converted into salts such as sodium salts or ammonium salts. This makes it easier for the viscosity modifier to exert its effect. The increased solubility makes it easier for the electrode slurry to When preparing the Lee, it is also possible to improve the dispersibility of the active material and other components. In this regard, cellulose and cellulose derivatives used as electrode binders are , and those salts shall also be included.

[0168] Water-soluble polymers stabilize viscosity by dissolving in water and can also be used as active materials or binders. Other materials to be combined with it, such as styrene-butadiene rubber, are stably separated in an aqueous solution. It can be dispersed. Furthermore, because it has functional groups, it is easily and stably adsorbed onto the surface of the active material. This is expected. Also, cellulose derivatives such as carboxymethylcellulose, For example, many materials have functional groups such as hydroxyl groups and carboxyl groups, and because they have functional groups, It is expected that the molecules will interact with each other and exist to broadly cover the surface of the active material.

[0169] When a binder covering or in contact with the surface of the active material forms a film, a passivation film is formed. It is also expected to play a role in suppressing the decomposition of the electrolyte. Here, the passivation membrane is , a film that does not conduct electrons, or a film with extremely low electrical conductivity, for example, the surface of an active material When a passivation film is formed, it suppresses the decomposition of the electrolyte at the battery reaction potential. This is possible. In addition, the passivation film suppresses electrical conductivity, and lithium ions conduct through it. It would be even better if it could be done.

[0170] <Method for fabricating electrodes> An example of an electrode fabrication method is shown. First, prepare the conductor 201. Here, a sheet is used as an example. A conductive material 201 is used. For the method of manufacturing the conductive material 201, refer to the previous embodiment. ru.

[0171] Next, the active material 103 and the solvent are mixed to prepare the first mixture. Here, the conductive additive Alternatively, a binder may be added and mixed. A polar solvent can be used as the solvent. Example For example, water, methanol, ethanol, acetone, tetrahydrofuran (THF), dimethyl Dimethylformamide (DMF), N-methylpyrrolidone (NMP), and dimethyl sulfoxide One or more of the following (DMSO) can be used: When using rubber material and a water-soluble polymer as a second material, water is used as the solvent. It is preferable.

[0172] Next, the first mixture prepared is applied onto the conductor 201. After that, heat treatment, etc. The solvent in the first mixture is evaporated to prepare layer 102.

[0173] (Embodiment 3) This embodiment describes an energy storage device according to one aspect of the present invention.

[0174] As an example of an energy storage device according to one aspect of the present invention, using an electrochemical reaction such as that of a lithium-ion battery Secondary batteries, electric double-layer capacitors, redox capacitors and other electrochemical capacitors, air Examples include gas batteries and fuel cells.

[0175] <Wound-type storage battery> As an example of an energy storage device, a wound-type battery will be described. Figure 12 shows a wound-type battery. Here is an example.

[0176] The energy storage device 980 shown in Figure 12 has a winding body 993 and an outer casing 983. 993 has an electrode 101, an electrode 151, and a separator 996. Also, the outer casing An electrolyte solution is injected into 983. Furthermore, the energy storage device 980 is connected to the conductor 201. It is preferable to have a lead electrode 997 and a lead electrode 998 connected to electrode 151. For electrodes 101 and 151, refer to the previous embodiment.

[0177] Here, as electrode 101, an electrode is used in which a layer 102 is fabricated on a strip-shaped conductor 201. Let's explain an example. Here, layer 102 is a lithium manganese composite oxide as the active material. This shows an example of possessing an object.

[0178] Here, the area of ​​the conductor 201 is, for example, 1 mm². 2 Over 100m 2 Below, 25mm 2 The above 1 0m 2 Below, 100mm 2 More than 3m 2 The following is acceptable.

[0179] In this case, the electrode 101 is an electrode in which a layer 102 is fabricated on a strip-shaped conductor 201. Although we have explained the examples of use, Figure 12 shows the energy storage device even when layer 102 is not present. 980 can be applied.

[0180] First, prepare electrodes 101 and 151. Here, the strip-shaped electrode 151 is a strip-shaped cluster The device can be fabricated by forming an active material layer on at least one of its surfaces. Here is an example. For example, copper is used as the current collector, and graphite is used as the active material in the active material layer. Next, Figure 1 As shown in 3(A), the lead electrode 997 is attached to the conductive material 201 of electrode 101, and electrode 1 The lead electrode 998 is joined to the current collector of 51. For example, ultrasonic is used to join the lead electrode. Wave welding or similar techniques can be used.

[0181] Next, as shown in Figure 13(B), from the bottom, we have electrode 101, separator 996, and electrode 151. The electrodes are then stacked in the order of separator 996. After that, the stacked electrodes are arranged as shown in Figure 14(A). The 101, electrode 151, and separator 996 are wound together to produce a wound body 993. In that case, you may use a core to wind it up.

[0182] Next, as shown in Figure 14(B), the winding body 993 is connected to the outer casing 983a and outer casing 983 It is wrapped by b. Then, the outer casing 983a and outer casing 983b are joined together. Here, the joining The outer casing is called the outer casing 983. The outer casing 983 is used to inject electrolyte into the outer casing. It is best to leave a portion where 983a and the outer casing 983b are not joined. It is sometimes called the injection port. The electrolyte is injected through the injection port. After that, the injection port is joined and the energy is stored. Device 980 will be manufactured.

[0183] Here, for example, a conductive material 201 is formed on one side of a strip-shaped separator 996, and then the conductive material is formed. A layer 102 may be formed on the body 201. That is, a conductor 201 on the separator 996 After laminating layer 102 and fixing separator 996, conductor 201 and layer 102, The electrode 151 and separator 996 may be laminated together.

[0184] When using an aprotic organic solvent as the solvent for the electrolyte, for example, ethylene Carbonate (EC), propylene carbonate (PC), butylene carbonate, chlorofluorocarbon ethylene carbonate, vinylene carbonate, γ-butyrolactone, γ-valerolactone Ton, Dimethyl carbonate (DMC), Diethyl carbonate (DEC), Ethylmeth Calcium carbonate (EMC), methyl formate, methyl acetate, methyl butyrate, 1,3-dioxane 1,4-Dioxane, Dimethoxyethane (DME), Dimethyl Sulfoxide, Diethyl Ether, methyl diglyme, acetonitrile, benzonitrile, tetrahydrofuran, One of the following: sulfolane, sultone, or any combination of two or more of these. It can be used in ratios.

[0185] Furthermore, by using a polymer material that gels as the solvent for the electrolyte, leakage properties can be addressed. Safety is enhanced. Furthermore, it becomes possible to make secondary batteries thinner and lighter. The high-molecular-weight components that are gelled... Typical examples of these materials include silicone gel, acrylic gel, acrylonitrile gel, and poly Ethylene oxide gels, polypropylene oxide gels, fluorine polymer gels These include:

[0186] Furthermore, as the solvent for the electrolyte, an ionic liquid (a room-temperature molten salt) that is flame-retardant and non-volatile is used. By using one or more of these devices, the internal temperature of the energy storage device may rise due to internal short circuits or overcharging. However, this can prevent the rupture or ignition of the energy storage device. Ionic liquids are composed of cations and anions. It consists of and contains organic cations and anions. As organic cations used in the electrolyte, four quaternary ammonium cations, tertiary sulfonium cations, and quaternary phosphonium cations Aliphatic onium cations such as imidazolium cations and pyridinium cations, etc. Aromatic cations are an example. In addition, monovalent amides are used as anions in the electrolyte. Anions, monovalent methide anions, fluorosulfonate anions, perfluoroalkyl Anions of tetrafluoroborate, perfluoroalkyl volate Toanions, hexafluorophosphate anions, or perfluoroalkyl phosphates Examples include ether anions.

[0187] When using lithium ions as the carrier in the electrolyte, for example, LiPF6 , LiClO4, LiAsF6, LiBF4, LiAlCl4, LiSCN, LiBr, LiI, Li2SO4, Li2B 10 Cl 10 Li2B 12 Cl 12 LiCF3SO 3, LiC4F9SO3, LiC(CF3SO2)3, LiC(C2F5SO2)3, L iN(CF3SO2)2, LiN(C4F9SO2)(CF3SO2), LiN(C2F One type of lithium salt such as 5SO2)2, or any combination of two or more of these. It can be used in proportion to the given value.

[0188] Furthermore, the electrolyte used in the energy storage device may contain particulate debris and elements other than the constituent elements of the electrolyte (hereinafter, It is preferable to use a highly purified electrolyte with a low content of impurities (also simply called "impurities"). Specifically, the amount of impurities in the electrolyte should be 1 weight% or less, preferably 0.1 weight%. It is preferable that the weight percentage be 8% or less, and more preferably 0.01 weight% or less.

[0189] Furthermore, the electrolyte contains vinylene carbonate, propanesultone (PS), and tert-butyl. Addition of benzene (TBB), fluoroethylene carbonate (FEC), LiBOB, etc. Additives may be added. The concentration of the additive should be, for example, 0.1 weight% or less of the total solvent. The upper 5 weight percentage should be less than or equal to 5.

[0190] Alternatively, a polymer gel electrolyte, obtained by swelling a polymer with an electrolyte solution, may be used.

[0191] Examples of polymers include polyalkylene oxides such as polyethylene oxide (PEO). Polymers having a side structure, PVDF, polyacrylonitrile, etc., and those Copolymers containing the above can be used. For example, PVDF and hexafluoropropylene ( PVDF-HFP, a copolymer of HFP, can be used. The rimer may have a porous structure.

[0192] In addition, instead of an electrolyte, a solid electrolyte containing inorganic materials such as sulfide-based or oxide-based materials may be used. Solid electrolytes containing polymer materials such as PEO (polyethylene oxide) can be used. It is possible. When using a solid electrolyte, the installation of separators and spacers becomes unnecessary. Also, Because the entire battery can be made solid, the risk of leakage is eliminated, dramatically improving safety.

[0193] For example, the separator 996 may be paper, nonwoven fabric, glass fiber, ceramics, or Nylon (polyamide), Vinylon (polyvinyl alcohol-based fiber), polyester, A This product uses synthetic fibers made from acrylic, polyolefin, polyurethane, etc. It is possible.

[0194] The storage battery 990 shown in Figure 15(A) has an outer casing 991 and outer casing that have a different shape from those in Figure 12. It has a body 992. Figure 15(B) shows the components of the storage battery 990. Inside the outer casing 991 The aforementioned coiled body 993 is housed in the section.

[0195] Outer casings 983, 991, and 992 are made of metal materials such as aluminum, for example. Resin materials can be used. If resin materials are used as the material for the exterior body, external forces can be applied. The ability to deform the outer casing when pressure is applied allows for the creation of a flexible storage battery. Yes, it is possible. For the outer casing, for example, polyethylene, polypropylene, polycarbonate, ion Aluminum, stainless steel, copper, nickel on a film made of materials such as nomer and polyamide. A highly flexible metal thin film is provided, and further, polyamide is used as the outer surface of the exterior body on the metal thin film. Using a three-layer film structure with an insulating synthetic resin film such as a chlorine resin or polyester resin. It is possible.

[0196] For example, if electrode 101 is used as the positive electrode, then electrode 151 can be used as the negative electrode. If electrode 101 is used as the negative electrode, then electrode 151 should be used as the positive electrode.

[0197] Specifically, for example, electrode 101 is used as the positive electrode, and the active material 103 of electrode 101 and The positive electrode active material shown in Embodiment 2 is used. For example, Li is used as the active material 103. a Mn b M c O d A lithium manganese composite oxide represented by [formula] is used. Also, electrode 151 is used as the negative electrode. The electrode 151 has the negative electrode active material shown in Embodiment 2.

[0198] Examples of various types of storage batteries are shown below. In the storage batteries shown below, as shown in Figure 13, etc. It is possible to refer to the descriptions of electrodes 101 and 151. For example, the positive electrode shown in Figure 17. 503 refers to the description of electrode 101 in Figure 13, and 506 refers to the negative electrode 151 in Figure 13. You can refer to the information regarding this matter.

[0199] As another example of wound-type storage batteries, Figure 16 shows a cylindrical storage battery. As shown in Figure 16(A), the battery 600 has a positive electrode cap (battery cover) 601 on its top surface. The battery can (outer casing) 602 is located on the side and bottom. These positive electrode cap and battery can ( The outer container (602) is insulated by a gasket (insulating packing) (610).

[0200] Figure 16(B) is a schematic diagram showing a cross-section of a cylindrical storage battery. Inside can 602, a strip-shaped positive electrode 604 and a negative electrode 606 are separated by a separator 605. A wound battery element is provided. Although not shown in the diagram, the battery element is centered around the center pin. It is wound up. Battery can 602 is closed at one end and open at the other end. This is a metal such as nickel, aluminum, or titanium that is corrosion-resistant to the electrolyte, or this These alloys or alloys of these with other metals (for example, stainless steel) can be used. Furthermore, to prevent corrosion from the electrolyte, it is preferable to coat the components with nickel, aluminum, etc. Inside the battery can 602, the positive electrode, negative electrode, and separator are wound together to form a battery element. It is sandwiched between a pair of opposing insulating plates 608 and 609. Furthermore, a battery element is provided. The inside of the battery can 602 is filled with a non-aqueous electrolyte (not shown). The non-aqueous electrolyte is A battery similar to a coin-type rechargeable battery can be used.

[0201] Since the positive and negative electrodes used in cylindrical storage batteries are wound, active material is formed on both sides of the current collector. It is preferable to do so. The positive electrode 604 is connected to the positive electrode terminal (positive electrode current collector lead) 603, and the negative The negative terminal (negative current collector lead) 607 is connected to pole 606. The positive terminal 603 and the negative Both electrode terminals 607 can be made of metal materials such as aluminum. Positive electrode terminal 6 Terminal 03 is resistance-welded to the safety valve mechanism 612, and the negative terminal 607 is resistance-welded to the bottom of the battery can 602. The safety valve mechanism 612 uses a PTC element (Positive Temperature C It is electrically connected to the positive electrode cap 601 via the efficient)611. The safety valve mechanism 612 activates the positive electrode cap 601 when the internal pressure of the battery rises above a predetermined threshold. This disconnects the electrical connection between the positive electrode 604 and the positive electrode 611. Also, the PTC element 611 is at a certain temperature. This is a thermal resistance element whose resistance increases when the temperature rises, and the increase in resistance limits the amount of current. This prevents abnormal heat generation. The PTC element uses barium titanate (BaTiO3) Semiconductor ceramics and the like can be used.

[0202] When winding electrodes, such as in a cylindrical storage battery as shown in Figure 16, large stresses are placed on the electrodes during winding. Large stresses act upon it. Also, when the electrode winding is housed in the casing, the electrode is always subjected to the winding axis. A stress acts outward. Even if a large stress acts on the electrode in this way, the active material This prevents the material from cleaving.

[0203] <Slim battery> As an example of an energy storage device, Figure 17 shows a thin battery. The thin battery is flexible. If this configuration is adopted, then when implemented in electronic equipment having at least a part of a flexible component, The battery can also be bent to match the deformation of the sub-device.

[0204] Figure 17 shows an external view of the thin battery 500. Also see Figures 18(A) and 18(B). Figure 17 shows the A1-A2 and B1-B2 cross-sections, indicated by dashed lines. This is a thin battery. 500 has a positive electrode 503 having a positive electrode current collector 501 and a positive electrode active material layer 502, and a negative electrode current collector A negative electrode 506 having a body 504 and a negative electrode active material layer 505, a separator 507, and an electrolyte It has 508 and an outer casing 509. A positive electrode 503 and a negative electrode 5 are provided inside the outer casing 509. A separator 507 is installed between 06 and 06. Also, inside the outer casing 509 is electrolyte 50 It is filled with 8.

[0205] The separator 507 is processed into a bag shape and encloses either the positive electrode 503 or the negative electrode 506. It is preferable to arrange them in such a way. For example, as shown in Figure 19(A), the positive electrode 503 is sandwiched between them. The separator 507 is folded in half, and the sealing portion 5 is formed outside the area that overlaps with the positive electrode 503. By sealing with 14, the positive electrode 503 can be securely supported within the separator 507. And, as shown in Figure 19(B), the positive electrode 503 enclosed in the separator 507 and the negative electrode By alternately stacking poles 506 and 509 and arranging them inside the outer casing 509, a thin storage battery 50 It is good to form 0.

[0206] Furthermore, in Figure 17, the positive lead electrode 510 and the negative lead electrode 511 are arranged on the same side. However, as shown in Figure 20, the positive lead electrode 510 and the negative lead electrode 511 are on different sides. They may be arranged as follows. Thus, in one aspect of the present invention, the storage battery allows the lead electrodes to be freely arranged. Because it allows for a high degree of design freedom, products using a storage battery according to one embodiment of the present invention This increases the design flexibility. Furthermore, it allows for the production of products using a battery according to one aspect of the present invention. It can enhance sexual performance.

[0207] The materials and structure of the outer casing 509 can be found in reference to outer casing 983, etc.

[0208] Figure 18 also shows, as an example, the number of pairs of opposing positive electrode active material layers and negative electrode active material layers is set to 5. However, of course, the number of electrode active material layers is not limited to five; there can be more or fewer. This is also good. When there are many electrode active material layers, it is possible to create a storage battery with a larger capacity. It is possible. Also, when the number of electrode active material layers is small, it is possible to make it thinner and create a rechargeable battery with excellent flexibility. It is possible.

[0209] Here, for example, the positive electrode 503 shown in Figure 17 is made up of a conductor 201 and a layer 102 on the conductor 201. Let's consider the case where layer 102 has positive electrode active material. In Figure 18, the storage battery 500 has Multiple positive electrodes 503 are stacked. Here, the area of ​​the conductor 201 of the positive electrode 503 is, for example... 1mm 2 1 meter or more 2 Below, 25mm 2 1 meter or more 2 Below, 100mm 2 Above 0.1m 2 Below The bottom is fine.

[0210] Next, various examples of stacking of positive, negative, and separator electrodes are shown.

[0211] Figure 21(A) shows an example in which six layers each of the positive electrode 111 and the negative electrode 115 are stacked. A positive electrode active material layer 122 is provided on one side of the positive electrode current collector 121 of electrode 111. A negative electrode active material layer 126 is provided on one side of the negative electrode current collector 125 of the negative electrode 115.

[0212] Furthermore, in the configuration shown in Figure 21(A), the positive electrode 111 does not have a positive electrode active material layer 122. The positive electrode 11 is in contact with the negative electrode 115, so that the surfaces of the negative electrode 115 that do not have the negative electrode active material layer 126 are in contact with each other. 1 and the negative electrode 115 are stacked. By stacking them in this order, the positive electrode active material of the positive electrode 111 The surfaces that do not have the material layer 122, and the surfaces that do not have the negative electrode active material layer 126 of the negative electrode 115 This allows for the creation of metal-to-metal contact surfaces. These metal-to-metal contact surfaces are formed between the active material and the separator. The coefficient of friction can be reduced compared to the contact surface.

[0213] Therefore, when the secondary battery 10 is bent, the positive electrode 111 does not have a positive electrode active material layer 122. The surfaces that do not have the negative electrode active material layer 126 of the negative electrode 115 slide against each other, thereby reducing the inner diameter of the curve. The stress caused by the difference in outer diameter can be relieved. Here, the inner diameter of the curve is, for example, that of a thin... When the storage battery 500 is curved, the outer casing 509 of the thin storage battery 500, This refers to the radius of curvature of the surface located on the inside. Therefore, it suppresses the degradation of the thin 500 battery. It can be controlled. Furthermore, it can be made into a highly reliable, slim 500-cell battery.

[0214] Furthermore, Figure 21(B) shows an example of stacking of positive electrode 111 and negative electrode 115 that differs from that shown in Figure 21(A). In the configuration shown in Figure 21(B), positive electrode active material layers 122 are provided on both sides of the positive electrode current collector 121. In this respect, it differs from the configuration shown in Figure 21(A). As shown in Figure 21(B), the positive electrode current collector By providing positive electrode active material layers 122 on both sides of 121, the unit volume of the thin storage battery 500 The capacity can be increased.

[0215] Furthermore, Figure 21(C) shows an example of stacking of positive electrode 111 and negative electrode 115 that differs from that shown in Figure 21(B). In the configuration shown in Figure 13(C), a negative electrode active material layer 126 is provided on both sides of the negative electrode current collector 125. In this respect, it differs from the configuration shown in Figure 13(B). As shown in Figure 13(C), the negative electrode current collector By providing negative electrode active material layers 126 on both sides of 125, the unit volume of the thin storage battery 500 The capacity can be further increased.

[0216] Furthermore, in the configuration shown in Figure 21, the separator 123 encloses the positive electrode 111 in a bag-like manner. Although the present invention has been configured in this way, it is not limited thereto. Here, in Figure 22(A), An example is shown of a separator 123 with a different configuration from 21(A). The configuration is shown in Figure 22(A). Next, a sheet-like separator 123 is placed between the positive electrode active material layer 122 and the negative electrode active material layer 126. This differs from the configuration shown in Figure 21(A) in that each sheet is provided individually. In this configuration, six layers each of positive electrode 111 and negative electrode 115 are stacked, and six layers of separator 123 are stacked. It is established.

[0217] Figure 22(B) also shows an example in which a different separator 123 is provided than in Figure 22(A). In the configuration shown in 22(B), one separator 123 separates the positive electrode active material layer 122 and the negative electrode active material In the point where it is folded back multiple times so as to be sandwiched between layers 126, as shown in Figure 22(A) The configuration is different. Also, the configuration in Figure 22(B) is different from the configuration in Figure 22(A) in terms of the separation of each layer. It can also be described as a configuration where Ta123 is extended and the layers are connected. This is shown in Figure 22(B). In this configuration, six layers each of the positive electrode 111 and the negative electrode 115 are stacked, and the separator 123 is used in small quantities. It is folded back at least five times. Also, the separator 123 is connected to the positive electrode active material layer 122 and the negative electrode In addition to being positioned between the active material layers 126, it is also extended to connect multiple positive electrodes 111 and negative electrodes. You may also bundle the 115 pieces together.

[0218] Alternatively, the positive electrode, negative electrode, and separator may be stacked as shown in Figure 23. Figure 23(A) Figure 23(B) shows a cross-sectional view of the first electrode assembly 130, and Figure 23(B) shows a cross-sectional view of the second electrode assembly 131. Figure 23(C) is a cross-sectional view along the dashed line A1-A2 in Figure 1(A). Note that Figure 23( In C), to make the diagram clearer, the first electrode assembly 130, electrode assembly 131 and separator are shown. Here is an excerpt from DATA 123.

[0219] As shown in Figure 23(C), the thin storage battery 500 has multiple first electrode assemblies 130 It has multiple electrode assemblies 131.

[0220] As shown in Figure 23(A), in the first electrode assembly 130, both sides of the positive electrode current collector 121 Positive electrode 111a having positive electrode active material layer 122, separator 123, and both sides of negative electrode current collector 125 Both the negative electrode 115a having a negative electrode active material layer 126, the separator 123, and the positive electrode current collector 121 The positive electrode 111a, which has a positive electrode active material layer 122 on its surface, is stacked in this order. Also, Figure 23( As shown in B), in the second electrode assembly 131, negative electrode active material is present on both sides of the negative electrode current collector 125. The negative electrode 115a has a layer 126, the separator 123, and positive electrode active material is present on both sides of the positive electrode current collector 121. Positive electrode 111a having a solid layer 122, separator 123, negative electrode current collector 125, both sides of which have a negative electrode active The negative electrode 115a, which has a material layer 126, is stacked in this order.

[0221] Furthermore, as shown in Figure 23(C), there are multiple first electrode assemblies 130 and multiple electrode sets The three-dimensional object 131 is covered by a wound separator 123.

[0222] <Coin-type rechargeable battery> An example of a coin-type rechargeable battery will be explained with reference to Figure 24. Figure 24(A) shows a coin. This is an external view of a single-layer flat-type storage battery, and Figure 24(B) is a cross-sectional view thereof. In this type of rechargeable battery, a positive electrode casing and a negative electrode casing are used as the outer casing.

[0223] The coin-type rechargeable battery 300 consists of a positive electrode can 301 which also serves as the positive terminal and a negative electrode can which also serves as the negative terminal. 302 is insulated and sealed by a gasket 303 made of polypropylene or the like. The positive electrode 304 consists of a positive electrode current collector 305 and a positive electrode active material layer 306 provided in contact with it. It is formed by

[0224] Furthermore, the negative electrode 307 consists of a negative electrode current collector 308 and a negative electrode active material provided in contact with it. It is formed by layer 309.

[0225] Furthermore, the positive electrode 304 and negative electrode 307 used in the coin-type storage battery 300 are each live metal The layers only need to be formed on one side.

[0226] The positive electrode can 301 and negative electrode can 302 contain nickel and aluminum, which are corrosion-resistant to the electrolyte. Metals such as titanium, or alloys of these or alloys of these with other metals (for example, stainless steel) Steel, etc. can be used. In addition, nickel or aluminum can be used to prevent corrosion by the electrolyte. It is preferable to coat with aluminum or the like. Positive electrode can 301 is positive electrode 304, and negative electrode can 302 is negative electrode 3 Connect each of them electrically to 07.

[0227] These negative electrode 307, positive electrode 304 and separator 310 are impregnated with the electrolyte, as shown in Figure 24. As shown in B), with the positive electrode can 301 at the bottom, the positive electrode 304, separator 310, and negative electrode 307... The negative electrode can 302 is stacked in this order, and the positive electrode can 301 and the negative electrode can 302 are connected by a gasket 303. The coin-shaped rechargeable battery 300 is manufactured by crimping the components together.

[0228] <Curvature of the exterior> The outer casing of the energy storage device has a minimum radius of curvature of, for example, 3 mm or more and 30 mm or less, more preferably. It can be deformed to be between 3mm and 10mm. It is the outer casing of the energy storage device. The film consists of one or two layers, and the curved cross-sectional structure of the battery is within the casing. It has a structure that is sandwiched between two curves of a film.

[0229] The radius of curvature of a surface will be explained using Figure 25. In Figure 25(A), the curved surface 170 In the plane 1701 that cuts through 0, a portion of the curve 1702 contained in the curved surface 1700 is a circle Approximating it as an arc, let the radius of the circle be the radius of curvature 1703, and the center of the circle be the center of curvature 1704. Figure 25(B) shows a top view of the curved surface 1700. Figure 25(C) shows the curved surface on plane 1701. The cross-sectional view of 1700 is shown. When a curved surface is cut by a plane, the angle of the plane relative to the curved surface... The radius of curvature of the curve appearing in the cross-section will differ depending on the cutting position, but in this specification, etc. The smallest radius of curvature is defined as the radius of curvature of the surface.

[0230] A curved energy storage device was constructed using two films as an outer casing, sandwiching the electrodes, electrolyte, and other components of the 1805. In this case, the radius of curvature 1802 of the film 1801 on the side closer to the center of curvature 1800 of the energy storage device. This is smaller than the radius of curvature 1804 of film 1803 on the side farther from the center of curvature 1800. Figure 26(A)). If the energy storage device is curved to make the cross-section arc-shaped, the center of curvature is close to 1800. Compressive stress is applied to the surface of the film, and tension is present on the surface of the film far from the center of curvature of 1800. Tension stress is applied (Figure 26(B)). Patterns are formed on the surface of the exterior body by recesses or protrusions. Once formed, even if compressive or tensile stresses are applied, the effects of strain remain. This can be kept within an acceptable range. Therefore, the energy storage device is located on the outer casing closer to the center of curvature. The minimum radius of curvature is, for example, 3 mm or more and 30 mm or less, more preferably 3 mm or more and 10 mm. It can be transformed so that it is less than or equal to m.

[0231] Furthermore, the cross-sectional shape of the energy storage device is not limited to a simple arc shape, but may have a shape in which part of it is an arc. It is possible to create shapes such as the one shown in Figure 26(C), a wavy shape (Figure 26(D)), or an S-shape. It is also possible to do so. When the radius of curvature changes due to the application of an external force to the energy storage device, The radius of curvature can be in the range of, for example, 3 mm to 30 mm. In the most curved state, i.e., the state with the smallest radius of curvature, the radius of curvature is preferable. The diameter is 3 mm to 10 mm, more preferably 3 mm to 6 mm. Here, the energy is stored. The radius of curvature of the device is such that if the curved surface of the energy storage device has a shape with multiple centers of curvature, In the surface with the smallest radius of curvature among the radii of curvature at each center of curvature, two It should be the smallest radius of curvature of the outer casing closest to the center of curvature of the outer casing.

[0232] <Curvature of conductors> Furthermore, a conductor according to one aspect of the present invention has a sheet-like shape, and its minimum radius of curvature is, for example, Deformed to be between 3mm and 30mm, more preferably between 3mm and 10mm. Therefore, a conductor according to one aspect of the present invention can be made to not crack or break down when wound or bent. It is difficult to wind. Therefore, it is suitable for wound-type energy storage devices. Furthermore, the conductor of one aspect of the present invention is suitable for energy storage. The device can deform as it is deformed by an external force. Therefore, in one aspect of the present invention By using a conductor in a flexible energy storage device, the reliability of the energy storage device can be improved. It is possible.

[0233] <Example of an energy storage system structure> Furthermore, an example of the structure of an energy storage system will be explained using Figures 27 to 29. An electrical system refers to, for example, equipment equipped with an energy storage device.

[0234] Figures 27(A) and 27(B) show external views of the energy storage system. The system comprises a circuit board 900 and a storage battery 913. The storage battery 913 has a label 91 A 0 is attached. Furthermore, as shown in Figure 27(B), the energy storage system has terminal 951 and It has terminal 952, antenna 914, and antenna 915.

[0235] The circuit board 900 has terminal 911 and circuit 912. Terminal 911 is connected to terminal 95 1. It is connected to terminal 952, antenna 914, antenna 915, and circuit 912. Oh, multiple terminals 911 are provided, and each of the multiple terminals 911 is a control signal input terminal, a power supply terminal, etc. It can also be used as a terminal, etc.

[0236] Circuit 912 may be provided on the back surface of circuit board 900. Note that antenna 914 And the antenna 915 is not limited to a coil shape, but may be, for example, linear or plate-shaped. Planar antenna, aperture antenna, traveling wave antenna, EH antenna, magnetic field antenna, induction An antenna such as an electrostatic antenna may be used. Alternatively, antenna 914 or antenna 91 5 may be a flat conductor. This flat conductor functions as one of the conductors for electric field coupling. This is possible. In other words, as one of the two conductors of the capacitor, Antenna 914 or antenna 915 may be activated. This will generate an electromagnetic field and a magnetic field. Furthermore, it is also possible to exchange power using an electric field.

[0237] The line width of antenna 914 is preferably larger than the line width of antenna 915. This allows for a greater amount of power to be received by antenna 914.

[0238] The energy storage system has a layer 9 between antennas 914 and 915 and the battery 913. It has 16. Layer 916 can shield electromagnetic fields, for example, from a storage battery 913. It has the ability to perform this function. For example, a magnetic material can be used as layer 916.

[0239] Note that the structure of the energy storage system is not limited to the structure shown in Figure 27.

[0240] For example, as shown in Figures 28(A-1) and 28(A-2), Figure 27(A) and In the battery 913 shown in Figure 27(B), antennas are provided on each of the two opposing sides. This is also acceptable. Figure 28(A-1) is an external view of the pair of surfaces as seen from one side, and Figure 2 8(A-2) is an external view of the pair of surfaces as seen from the other side. Note that Figure 27(A) And for the same parts as the energy storage system shown in Figure 27(B), see Figures 27(A) and 2 The explanation of the energy storage system shown in 7(B) can be used as appropriate.

[0241] As shown in Figure 28(A-1), a layer 916 is sandwiched between one of the pair of surfaces of the storage battery 913. An incubator 914 is provided, and as shown in Figure 28(A-2), on the other side of the battery 913 An antenna 915 is provided on one side, with layer 917 in between. Layer 917 is, for example, connected to a storage battery 913. It has the function of shielding electromagnetic fields. For layer 917, for example, a magnetic material is used. It is possible to be there.

[0242] By adopting the above structure, the size of both antenna 914 and antenna 915 can be increased. It is possible to hear.

[0243] Alternatively, as shown in Figures 28(B-1) and 28(B-2), Figure 27(A) and Of the storage battery 913 shown in Figure 27(B), a separate antenna is attached to each of the two opposing sides. It may be provided. Figure 28(B-1) is an external view of the pair of surfaces as seen from one side. Figure 28(B-2) is an external view of the pair of surfaces as seen from the other side. Note that Figure 27( For the same parts as the energy storage system shown in A) and Figure 27(B), see Figure 27(A) and The explanation of the energy storage system shown in Figure 27(B) can be used as appropriate.

[0244] As shown in Figure 28(B-1), a layer 916 is sandwiched between one of the pair of surfaces of the storage battery 913. An antenna 914 and an antenna 915 are provided, and as shown in Figure 28(B-2), the storage battery An antenna 918 is provided on the other side of the pair of faces of 913, with layer 917 in between. Antenna 91 8, for example, has the function of being able to communicate data with external devices. Antenna 91 For example, antennas with shapes applicable to antennas 914 and 915 can be applied to 8. This is possible. It is a communication method between the energy storage system and other devices via antenna 918. This involves applying response methods that can be used between the energy storage system and other devices, such as NFC. It is possible.

[0245] Alternatively, as shown in Figure 29(A), the storage battery 91 shown in Figures 27(A) and 27(B) A display device 920 may be provided at 3. The display device 920 is connected to terminal 911 via terminal 919. It is electrically connected to the display device 920. It is not necessary. Furthermore, the same parts as the energy storage system shown in Figures 27(A) and 27(B) In this regard, the explanation of the energy storage system shown in Figures 27(A) and 27(B) can be appropriately referenced.

[0246] The display device 920 may display, for example, an image indicating whether or not it is charging, an image indicating the amount of stored power, etc. It may be displayed. The display device 920 may be, for example, electronic paper, liquid crystal display device, etc. A trollescent (also known as EL) display device can be used. For example, an electronic paper By using a supercharger, the power consumption of the display device 920 can be reduced.

[0247] Alternatively, as shown in Figure 29(B), the storage battery 91 shown in Figures 27(A) and 27(B) A sensor 921 may be provided at 3. The sensor 921 receives power from terminal 911 via terminal 922. It is electrically connected. Note that it is the same part as the energy storage system shown in Figures 27(A) and 27(B). For details, please refer to the explanation of the energy storage system shown in Figures 27(A) and 27(B) as appropriate. Cut.

[0248] Examples of sensors 921 include force, displacement, position, velocity, acceleration, angular velocity, rotational speed, and distance. Separation, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, electric current, voltage, power, radiation Use a device that includes functions for measuring radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation. This is possible. By providing the sensor 921, for example, the environment in which the energy storage system is located can be detected. It is also possible to detect data indicating this (such as temperature) and store it in the memory within circuit 912. .

[0249] The battery and energy storage system shown in this embodiment use electrodes according to one aspect of the present invention. Therefore, the capacity of batteries and energy storage systems can be increased. Energy density can be increased. Reliability can be improved. Furthermore, lifespan can be extended. It can be done.

[0250] This embodiment can be implemented in appropriate combination with other embodiments.

[0251] (Embodiment 4) This embodiment describes an example of mounting a flexible energy storage device in an electronic device. .

[0252] Figure 30 shows an example of mounting the flexible energy storage device described in Embodiment 2 onto an electronic device. Electronic devices that utilize energy storage devices with flexible shapes include, for example, televisions. Devices (also called televisions or television receivers), monitors for computers, etc. Digital cameras, digital video cameras, digital photo frames, mobile phones (mobile phones, (Also called mobile phone devices), portable game consoles, personal information terminals, sound playback devices, pachinko machines, etc. Examples include large game consoles.

[0253] Furthermore, energy storage devices with flexible shapes can be installed in the interior or exterior walls of houses and buildings, or in automatic It can also be integrated to conform to the curved surfaces of the car's interior or exterior.

[0254] Figure 30(A) shows an example of a mobile phone. The mobile phone 7400 has a housing 740 In addition to the display unit 7402 incorporated into 1, there are also operation buttons 7403, an external connection port 7404, It is equipped with speaker 7405, microphone 7406, etc. Note that the mobile phone 7400 is a storage It has an electrical device 7407.

[0255] Figure 30(B) shows the mobile phone 7400 in a curved state. When 00 is deformed by an external force and the whole thing is bent, the power storage device located inside it The 7407 is also bent. Figure 30 shows the state of the bent energy storage device 7407 at that time. As shown in C), the energy storage device 7407 is a thin battery. The energy storage device 7407 is bent. It is fixed in place. Furthermore, the energy storage device 7407 is electrically connected to the current collector 7409. It has a copper electrode 7408. For example, the current collector 7409 is copper foil, and partly gallium By alloying, the adhesion between the current collector 7409 and the active material layer in contact with it is improved, and the energy storage device 7407 This configuration offers high reliability even when bent.

[0256] Figure 30(D) shows an example of a bangle-type display device. The portable display device 7100 is It comprises a housing 7101, a display unit 7102, operation buttons 7103, and a power storage device 7104. Figure 30(E) also shows the state of the bent energy storage device 7104. The energy storage device 7104 is When worn on the user's arm in a bent state, the casing deforms, causing part of the power storage device 7104 to be damaged. The curvature of the curve changes across the entire curve. Note that the degree of curvature at any point in the curve is the radius of the corresponding circle. The value expressed as is the radius of curvature, and the reciprocal of the radius of curvature is called the curvature. Specifically, the half of the radius of curvature A portion of the main surface of the housing or energy storage device 7104, within the range of 40 mm to 150 mm in diameter Or the whole thing changes. The radius of curvature on the main surface of the energy storage device 7104 is 40 mm or more 15 High reliability can be maintained within a range of 0 mm or less.

[0257] Figure 30(F) shows an example of a wristwatch-type personal information terminal. Personal information terminal 7200 The components are: housing 7201, display unit 7202, band 7203, buckle 7204, and operation button 7 It is equipped with terminals 205 and input / output terminals 7206, etc.

[0258] The 7200 mobile information terminal offers mobile phone calls, email, document viewing and creation, music playback, and more. It can run various applications such as internet communication and computer games. Cut.

[0259] The display unit 7202 has a curved display surface, and displays information along the curved surface. It is possible to do so. In addition, the display unit 7202 is equipped with a touch sensor, and the screen can be touched with a finger or stylus. It can be operated by touching it. For example, icon 7 displayed on the display unit 7202 Touching 207 will launch the application.

[0260] The 7205 control button is used for time setting, as well as power on / off, wireless communication on, and more. Various functions such as operation, activation and deactivation of silent mode, and activation and deactivation of power saving mode. It can be made to hold. For example, the operating system built into the personal digital assistant 7200 The system also allows you to freely configure the function of the control button 7205.

[0261] Furthermore, the 7200 portable information terminal is capable of performing standardized short-range wireless communication. For example, by communicating with a wireless headset, hands-free operation is possible. You can also make calls.

[0262] Furthermore, the portable information terminal 7200 is equipped with an input / output terminal 7206, and can connect to other information terminals. Data can be exchanged directly via this. Also, charging is possible via input / output terminal 7206. It can also perform electrical operations. Note that charging is done wirelessly without using input / output terminal 7206. You may go.

[0263] The display unit 7202 of the portable information terminal 7200 is equipped with an electrode member according to one aspect of the present invention for energy storage. It has a device. For example, the energy storage device 7104 shown in Figure 30(E) is housed in a casing 7201. It can be incorporated in a curved state internally, or in a state that allows it to be curved internally within the band 7203. can.

[0264] The personal information terminal 7200 preferably has a sensor. For example, a fingerprint sensor. Human body sensors such as pulse sensors and body temperature sensors, as well as touch sensors, pressure sensors, and accelerometers. It is preferable that sensors, etc., be installed.

[0265] Figure 30(G) shows an example of an armband-type display device. The display device 7300 is a display unit The device has 7304 and has an energy storage device according to one aspect of the present invention. Furthermore, the display device 7300 is The display unit 7304 can also be equipped with a touch sensor, and it can also function as a portable information terminal. It is also possible to do so.

[0266] The display unit 7304 has a curved display surface, and displays are performed along the curved display surface. This is possible. In addition, the display device 7300 can display information via standardized short-range wireless communication. The situation can be changed.

[0267] Furthermore, the display device 7300 is equipped with input / output terminals and can be directly connected to other information terminals via connectors. It can exchange data. It can also be charged via its input / output terminals. Furthermore, charging may be performed wirelessly without using input / output terminals.

[0268] This embodiment can be implemented in appropriate combination with other embodiments.

[0269] (Embodiment 5) This embodiment shows an example of an electronic device that can be equipped with an energy storage device.

[0270] Figures 31(A) and 31(B) show an example of a foldable tablet device. The tablet terminal 9600 shown in Figures 31(A) and 31(B) has a housing 9630a, Housing 9630b, movable part 9640 connecting housing 9630a and housing 9630b, display unit 9 Display unit 9631 having 631a and display unit 9631b, display mode switching switch 96 26. Power switch 9627, power saving mode switch 9625, fastener 9629 It has an operating switch 9628. Figure 31(A) shows the tablet terminal 9600 opened. Figure 31(B) shows the state in which the tablet terminal 9600 is closed.

[0271] Furthermore, the tablet terminal 9600 stores inside the housings 9630a and 9630b. It has an electric body 9635. The electric body 9635 passes through the movable part 9640 and the housing 9630a and the housing It is provided across body 9630b.

[0272] The display unit 9631a can be partially designated as a touch panel area 9632a, and the display will Data can be entered by touching the operation key 9638. Note that the display unit 96 In 31a, as an example, one half of the area has a display-only function, and the other half of the area The area indicates a configuration having touch panel functionality, but is not limited to this configuration. Display unit 96 The entire area of ​​31a may also be configured to have touch panel functionality. For example, the display unit 9 The entire surface of 631a is used as a touch panel with keyboard buttons, and the display unit 9631b is displayed It can be used as a display screen.

[0273] In addition, in the display unit 9631b, similar to the display unit 9631a, one of the display units 9631b The area can be designated as the touch panel area 9632b. Also, the touch panel keyboard Touch the location where the display toggle button 9639 is displayed using your finger or stylus. This allows keyboard buttons to be displayed on the display unit 9631b.

[0274] Furthermore, simultaneously with respect to the touch panel area 9632a and the touch panel area 9632b You can also use touch input.

[0275] Additionally, the display mode switch 9626 changes the display orientation, such as portrait or landscape. You can switch between modes, such as switching between black and white and color displays. Power saving mode switching... The switch 9625 is used by the light sensor built into the tablet terminal 9600. The display brightness can be optimized according to the amount of ambient light at the time. (Tablet device) In addition to optical sensors, other sensors such as gyroscopes and accelerometers that detect tilt are also used. An output device may be built into the device.

[0276] Furthermore, Figure 31(A) shows an example where the display area of ​​display unit 9631b and display unit 9631a are the same. However, this is not particularly limited, and one size may be different from the other. The quality of the display may also differ. For example, one display panel can provide a higher resolution display than the other. You can also use "ru".

[0277] Figure 31(B) shows the closed state, and the tablet terminal consists of a housing 9630 and a solar cell 9 633, it has a charge / discharge control circuit 9634 including a DC-DC converter 9636. As body 9635, a power storage body according to one aspect of the present invention is used.

[0278] Furthermore, since the tablet device 9600 is foldable, the casing 9630a can be folded in half when not in use. The casing 9630b can be folded so that it overlaps with the other casing. Therefore, the display unit 9631a and the display unit 9631b can be protected, thus the tablet terminal 9600 Durability can be increased. Furthermore, the energy storage body 9635 using the energy storage body according to one aspect of the present invention is It is flexible and its charge / discharge capacity does not easily decrease even after repeated bending and stretching. Therefore, reliability We can provide excellent tablet devices.

[0279] In addition, there are various other tablet devices, as shown in Figures 31(A) and 31(B). Features that display information (still images, videos, text images, etc.), calendar, date or time. Functions that display such information on the display unit, and touch input operations or editing of the information displayed on the display unit. It has features such as input functionality and the ability to control processing through various software (programs). It is possible.

[0280] The touch panel is powered by a solar cell 9633 mounted on the surface of the tablet device. It can be supplied to the display unit or the video signal processing unit, etc. The solar cell 9633 is It can be installed on one or both sides of the housing 9630, and efficiently charges the energy storage unit 9635. This configuration can be achieved. Furthermore, if a lithium-ion battery is used as the energy storage element 9635, This offers advantages such as the ability to miniaturize the device.

[0281] Furthermore, the configuration and operation of the charge / discharge control circuit 9634 shown in Figure 31(B) are shown in Figure 31. (C) shows a block diagram and provides an explanation. Figure 31(C) shows a solar cell 9633 and a power storage unit 96 35. DC-DC converter 9636, converter 9637, switch SW1 to SW3, The display unit 9631 is shown, along with the energy storage unit 9635, the DC-DC converter 9636, and Converter 9637, switches SW1 to SW3, and the charge / discharge control circuit 9 shown in Figure 31(B) This corresponds to section 634.

[0282] First, let's explain an example of how the solar cell 9633 operates when generating electricity using ambient light. The electricity generated by the solar cells is converted into a DC-DC converter to provide the voltage necessary to charge the 9635 energy storage unit. The converter 9636 performs voltage boosting or bucking. Then, the solar power is used to control the operation of the display unit 9631. When power from pond 9633 is used, switch SW1 is turned ON, and converter 963 In step 7, the voltage is increased or decreased to the required voltage for the display unit 9631. Also, the display unit 963 If you do not want to display in step 1, turn SW1 off and turn SW2 on to enable the storage unit 9635. The configuration should include charging capabilities.

[0283] While solar cell 9633 is shown as an example of a power generation method, it is not particularly limited to this method. Storage using other power generation methods such as piezoelectric elements (piezo elements) and thermoelectric elements (Peltier elements) The configuration may also involve charging the battery 9635. For example, power may be transmitted and received wirelessly (contactlessly). This includes contactless power transmission modules that charge via this method, as well as configurations that combine this with other charging methods. You may do so.

[0284] Figure 32 shows an example of another electronic device. In Figure 32, the display device 8000 is the present invention. This is an example of an electronic device using a power storage device 8004 according to one embodiment. Specifically, the display device 80 00 corresponds to a display device for receiving TV broadcasts, and consists of a housing 8001, a display unit 8002, and a speaker. It has part 8003, a power storage device 8004, etc. A power storage device 8004 according to one aspect of the present invention is It is located inside the enclosure 8001. The display device 8000 receives power from the commercial power supply. You can receive power from it, or you can use the power stored in the energy storage device 8004. Therefore, even when power cannot be supplied from the commercial power source due to a power outage or the like, according to one aspect of the present invention By using the energy storage device 8004 as an uninterruptible power supply, the display device 8000 can be used. Yes.

[0285] The display unit 8002 has light-emitting elements such as liquid crystal display devices and organic EL elements in each pixel. Optical devices, electrophoresis display devices, DMDs (Digital Micromirror Dev ice), PDP (Plasma Display Panel), FED (Field Semiconductor display devices such as Emission Displays can be used.

[0286] In addition to being used for receiving TV broadcasts, the display devices are also used for personal computers and for displaying advertisements. This includes all information display devices.

[0287] In Figure 32, the fixed lighting device 8100 is a power storage device 8 according to one aspect of the present invention. This is an example of an electronic device using 103. Specifically, the lighting device 8100 has a housing 8101, It has a light source 8102, a power storage device 8103, etc. In Figure 32, the power storage device 8103 is located in the housing 8 For example, consider the case where 101 and the light source 8102 are installed inside the ceiling 8104. Although shown, the energy storage device 8103 may be located inside the housing 8101. The device 8100 can receive power from the commercial power supply, or from the energy storage device 8103. It is also possible to use stored power. Therefore, in the event of a power outage, etc., power supply from commercial power source Even when it is not possible to receive a power supply, the energy storage device 8103 according to one aspect of the present invention can be used as an uninterruptible power supply. This makes it possible to use the lighting device 8100.

[0288] In Figure 32, a fixed lighting device 8100 installed on the ceiling 8104 is shown as an example. However, in one aspect of the present invention, the energy storage device can be used not only on the ceiling 8104, but also on the side walls 8105, floor, etc. It can also be used in fixed lighting devices installed in windows such as 8106 and 8107, and also in tables It can also be used in overhead lighting fixtures and other applications.

[0289] Furthermore, the light source 8102 can use an artificial light source that artificially obtains light using electricity. Yes, it is possible. Specifically, this includes discharge lamps such as incandescent light bulbs and fluorescent lamps, and LEDs and organic EL elements. Optical elements are an example of the artificial light sources mentioned above.

[0290] In Figure 32, the air conditioner having an indoor unit 8200 and an outdoor unit 8204 is This is an example of an electronic device using the energy storage device 8203 according to one aspect of the present invention. Specifically, the room The internal unit 8200 includes a housing 8201, an air outlet 8202, a power storage device 8203, etc. (Figure 32) The example given is that the energy storage device 8203 is installed in the indoor unit 8200, The electrical device 8203 may be installed on the outdoor unit 8204. Alternatively, it may be installed on the indoor unit 8200 and the room Both outdoor units 8204 may be equipped with energy storage devices 8203. - It can receive power from the commercial power supply, or stored in the energy storage device 8203 Electricity can also be used. In particular, both the indoor unit 8200 and the outdoor unit 8204 are equipped with energy storage devices 8 If 203 is installed, when power cannot be supplied from the commercial power source due to a power outage, etc. However, by using the energy storage device 8203 according to one aspect of the present invention as an uninterruptible power supply, Conditioner can be used.

[0291] Figure 32 shows a separate-type air conditioner consisting of an indoor unit and an outdoor unit. The example shown is an integrated air conditioner that has both the indoor and outdoor unit functions in a single housing. A power storage device according to one aspect of the present invention can also be used as the conditioner.

[0292] In Figure 32, the electric refrigerator 8300 is a power storage device 8304 according to one aspect of the present invention. This is an example of an electronic device using [a specific component]. Specifically, the electric refrigerator 8300 has a casing 8301, It has a refrigerator door 8302, a freezer door 8303, an energy storage device 8304, etc. In Figure 32, The energy storage device 8304 is located inside the casing 8301. The electric refrigerator 8300 is It can also receive power from the commercial power supply, or the power stored in the energy storage device 8304 It is also possible to use this. Therefore, if power cannot be supplied from the commercial power source due to a power outage, etc. Even at times, by using the energy storage device 8304 according to one aspect of the present invention as an uninterruptible power supply, The 8300 refrigerator / freezer will become available for use.

[0293] Of the electronic devices mentioned above, high-frequency heating devices such as microwave ovens and electric rice cookers are included. Sub-devices require high power for short periods. Therefore, they need to supplement the power that cannot be supplied by the commercial power supply. By using an energy storage device according to one aspect of the present invention as an auxiliary power source to assist, electronic equipment This prevents the commercial power circuit breaker from tripping when using it.

[0294] Furthermore, during periods when electronic devices are not in use, especially the total amount of electricity that can be supplied by the commercial power source... Of these, during the time periods when the proportion of electricity actually used (called the electricity usage rate) is low, storage By storing electricity in the electrical equipment, the rate of electricity use outside of the above-mentioned time period can be suppressed. It is possible. For example, in the case of the electric refrigerator 8300, when the temperature is low, the refrigerator door 83 02. At night when the freezer door 8303 is not opened or closed, power is supplied to the energy storage device 8304. Store. Then, as the temperature rises, the refrigerator door 8302 and the freezer door 8303 are opened and closed. During the daytime, by using the energy storage device 8304 as an auxiliary power source, daytime electricity usage The rate can be kept low.

[0295] This embodiment can be implemented in appropriate combination with other embodiments.

[0296] (Embodiment 6) This embodiment shows an example in which a power storage device is installed in a vehicle.

[0297] Furthermore, when a battery storage device is installed in a vehicle, hybrid electric vehicles (HEVs) and electric vehicles (EVs) or next-generation clean energy vehicles such as plug-in hybrid vehicles (PHEVs) It can be expressed.

[0298] Figure 33 illustrates a vehicle using one embodiment of the present invention. The automobile shown in Figure 33(A) The 8400 is an electric vehicle that uses an electric motor as its power source for propulsion. It is possible to appropriately select and use an electric motor and an engine as the power source for propulsion. This is a hybrid vehicle. By using one aspect of the present invention, a vehicle with a long driving range can be realized. It is possible. Furthermore, the automobile 8400 has a power storage device. The power storage device is an electric motor In addition to driving the 8406, it also powers the headlights 8401 and interior lights (not shown), etc. It can supply power to the light-emitting device.

[0299] Furthermore, the energy storage device is used for the speedometer, tachometer, and other displays of the 8400 automobile. It can supply power to the display device. In addition, the energy storage device is the navigation system of the automobile 8400. It can supply power to semiconductor devices such as gate systems.

[0300] The automobile 8500 shown in Figure 33(B) plugs into the energy storage device of the automobile 8500. It can be charged by receiving power from an external charging facility using methods such as contactless power supply. It can be done. Figure 33(B) shows the ground-mounted charging device 8021 being mounted on the automobile 8500. This shows the state in which the energy storage device 8024 is being charged via cable 8022. Therefore, charging methods and connector specifications are subject to the standards of CHAdeMO (registered trademark) and Combo, etc. This can be done as appropriate. The charging device 8021 is a charging station installed in a commercial facility. However, it is also fine to use a household power supply. For example, plug-in technology allows external power to be supplied. The power supply can be used to charge the energy storage device 8024 installed in the automobile 8500. Charging is performed by converting AC power to DC power via a conversion device such as an AC / DC converter. It is possible.

[0301] Although not shown in the diagram, a power receiving device is mounted on the vehicle, and power is supplied wirelessly from a ground-based power transmission device. It can also be charged by supplying power. In this contactless power supply method, the power transmission equipment is installed on the road or exterior wall. By incorporating this, charging can be performed not only when the vehicle is stopped but also while it is in motion. The electric system may be used to transmit and receive power between vehicles. Furthermore, the exterior of the vehicle Solar panels may be installed to charge the energy storage device when the vehicle is stopped or in motion. Electromagnetic induction and magnetic resonance methods can be used to supply power in this environment.

[0302] According to one aspect of the present invention, the cycle characteristics of the energy storage device are improved, and its reliability is enhanced. It is possible to do so. Furthermore, according to one aspect of the present invention, the characteristics of the energy storage device can be improved. Therefore, the energy storage device itself can be made smaller and lighter. This contributes to reducing the vehicle's weight, thus improving its driving range. The installed energy storage device can also be used as a power source other than the vehicle. In this case, the power demand This allows us to avoid using commercial power during peak hours.

[0303] This embodiment can be implemented in appropriate combination with other embodiments.

[0304] (Embodiment 7) A battery that can be used in combination with a battery cell containing the materials described in the above embodiment. Control unit (Battery Management Unit: BMU), and the power For transistors suitable for the circuits constituting the pond control unit, refer to Figures 34 to 40. This will be explained. In this embodiment, in particular, the power of a storage device having battery cells connected in series Let me explain the pond control unit.

[0305] When multiple battery cells connected in series are repeatedly charged and discharged, the characteristics between the battery cells change. The capacity (output voltage) will vary depending on the variation in properties. The total discharge capacity depends on the battery cells with the smallest capacity. If there is variation in capacity... The capacity during discharge will be smaller. Also, if charging is performed using a battery cell with a smaller capacity as the baseline, There is a risk of insufficient power. Also, if charging is performed based on a larger capacity battery cell, overcharging may occur. There is a risk that this will happen.

[0306] Therefore, the battery control unit of an energy storage device having battery cells connected in series is unable to charge. It has a function to equalize the capacity variations between battery cells, which can cause problems such as overcharging. Circuit configurations to equalize the capacitance variations between components include resistor methods, capacitor methods, or inverter methods. There are duct-type methods, but here we use a transistor with a small off-current to handle capacitance variations. I will explain by giving an example of a circuit configuration that can provide these features.

[0307] As a transistor with a low off-current, a transistor having an oxide semiconductor in the channel formation region is... A transistor (OS transistor) is preferred. An OS transistor with a small off-current is used for energy storage. By using it in the circuit configuration of the device's battery control unit, the amount of charge leaking from the battery is reduced. This can suppress the decrease in capacity over time.

[0308] The oxide semiconductor used in the channel formation region is In-M-Zn oxide (where M is Ga, Sn (Y, Zr, La, Ce, or Nd) are used. Used to form oxide semiconductor films. In the target, the atomic ratio of the metal elements is In:M:Zn = x1:y1:z1. and 、 x1 / y1 is between 1 / 3 and 6, and moreover, between 1 and 6, and z1 / y1 is It is preferable that z1 / y1 is between 1 / 3 and 6, and more preferably between 1 and 6. By setting the value to 6 or less, the CAAC-OS film is more easily formed as an oxide semiconductor film. .

[0309] Now, let's discuss the CAAC-OS membrane.

[0310] CAAC-OS film is an oxide semiconductor film having multiple c-axis oriented crystalline regions. .

[0311] Transmission Electron Microscope (TEM) A composite image of the bright-field image and diffraction pattern of the CAAC-OS film was obtained using an optical scope. By observing (also known as high-resolution TEM images), multiple crystalline regions can be identified. On the other hand, high-resolution TEM images also clearly show the boundaries between crystal parts, i.e., grain boundaries. It is not possible to confirm the boundary (also called the boundary). Therefore, the CAAC-OS membrane is This means that a decrease in electron mobility due to grain boundaries is less likely to occur.

[0312] When observing a high-resolution TEM image of the cross-section of the CAAC-OS film from a direction approximately parallel to the sample surface, In the crystalline region, it can be confirmed that the metal atoms are arranged in layers. Each layer of metal atoms is This reflects the unevenness of the surface (also called the surface to be formed) or the upper surface of the CAAC-OS film. It has a specific shape and is arranged parallel to the surface or top surface of the CAAC-OS film to be formed.

[0313] On the other hand, a high-resolution TEM image of the CAAC-OS film plane was observed from a direction approximately perpendicular to the sample surface. Then, it was confirmed that the metal atoms in the crystalline region are arranged in a triangular or hexagonal shape. Yes, it is possible. However, no regularity is observed in the arrangement of metal atoms between different crystalline regions.

[0314] X-ray diffraction (XRD) of CAAC-OS film When structural analysis is performed using the instrument, for example, CAAC-OS having InGaZnO4 crystals is found. Out-of-plane analysis of the film showed a peak at a diffraction angle (2θ) of around 31°. This peak may appear. This peak is attributed to the (009) plane of the InGaZnO4 crystal. Therefore, the crystals of the CAAC-OS film have c-axis orientation, and the c-axis is on the surface to be formed or on the upper surface. It can be confirmed that it is facing in a nearly vertical direction.

[0315] Furthermore, the out-of-plane CAAC-OS film having InGaZnO4 crystals Analysis using this method revealed that in addition to the peak near 2θ = 31°, there is also a peak near 2θ = 36°. In some cases, this may occur. Peaks near 2θ of 36° indicate c-axis orientation in a portion of the CAAC-OS film. This indicates the presence of crystals that do not possess properties. The CAAC-OS film has a 2θ of approximately 31°. It is preferable that a peak is shown and that no peak is shown near 36° for 2θ.

[0316] CAAC-OS films are oxide semiconductor films with low impurity concentrations. The impurities include hydrogen and carbon. These are elements other than the main components of oxide semiconductor films, such as silicon and transition metal elements. In particular, silicon Elements such as condensate, which have a stronger bonding force with oxygen than the metal elements that make up oxide semiconductor films, are acidic. By removing oxygen from the oxide semiconductor film, the atomic arrangement of the oxide semiconductor film is disrupted, reducing its crystallinity. This is a contributing factor. Also, heavy metals such as iron and nickel, argon, and carbon dioxide have a high atomic ratio. Because of its large diameter (or molecular radius), when it is contained within an oxide semiconductor film, the oxide semiconductor film This disrupts the atomic arrangement and reduces crystallinity. Pure substances can act as carrier traps or carrier sources.

[0317] Furthermore, CAAC-OS films are oxide semiconductor films with a low defect level density. For example, oxidation Oxygen vacancies in semiconductor films can act as carrier traps or capture hydrogen. This can sometimes become a source of carrier transmission.

[0318] A low impurity concentration and low defect level density (few oxygen vacancies) are referred to as high-purity intrinsic or This is essentially called high-purity intrinsic. Oxide semiconductors that are high-purity intrinsic or substantially high-purity intrinsic. Because membranes have fewer carrier sources, they can have lower carrier densities. Therefore The transistor using the oxide semiconductor film exhibits electrical characteristics such as a negative threshold voltage. It rarely becomes (also called normally-on). Also, it is of high purity and is essentially high purity. Intrinsically pure oxide semiconductor films have few carrier traps. Therefore, the oxide semiconductor film Transistors using conductive films exhibit less variation in electrical characteristics and are highly reliable. Yes. Furthermore, the charge trapped in the carrier trap of the oxide semiconductor film requires time to be released. This can last for a long time, sometimes behaving as if it were a fixed charge. Therefore, the impurity concentration Transistors using oxide semiconductor films with high defect level density have unstable electrical properties. This can sometimes happen.

[0319] Furthermore, transistors using CAAC-OS films exhibit electrical properties when irradiated with visible light or ultraviolet light. Sexual variation is small.

[0320] OS transistors are transistors that have silicon in the channel formation region (Si Because it has a larger band gap compared to a transistor, dielectric breakdown when a high voltage is applied is It is unlikely to occur. When battery cells are connected in series, a voltage of several hundred volts will be generated, The circuit configuration of the battery control unit of the energy storage device applied to such battery cells includes the aforementioned O It is suitable to construct it using S-transistors.

[0321] Figure 34 shows an example of a block diagram of an energy storage device. The energy storage device BT00 shown in Figure 34 is Terminal pair BT01, terminal pair BT02, switching control circuit BT03, switching circuit BT 04, switching circuit BT05, transformer control circuit BT06, transformer circuit BT07, in series It has a battery section BT08 which includes a plurality of connected battery cells BT09.

[0322] Furthermore, in the energy storage device BT00 shown in Figure 34, terminal pair BT01 and terminal pair BT02 are connected. Switching control circuit BT03, switching circuit BT04, switching circuit BT05, and transformer control The part consisting of the control circuit BT06 and the transformer circuit BT07 is called the battery control unit. It can be done.

[0323] The switching control circuit BT03 controls the operation of switching circuits BT04 and BT05. It controls the following. Specifically, the switching control circuit BT03 measures each battery cell BT09 and Based on the voltage, the battery cells to be discharged (discharge battery cell group) and the battery cells to be charged (charge battery cell group) are selected. Determine the battery cell group.

[0324] Furthermore, the switching control circuit BT03 controls the determined group of discharged battery cells and the rechargeable battery cells. Based on the group, control signals S1 and S2 are output. Control signal S1 is a switching signal. The signal is output to circuit BT04. This control signal S1 connects terminal pair BT01 and the group of discharge battery cells. This is a signal that controls the switching circuit BT04 to connect. Also, the control signal S2 is, The signal is output to the switching circuit BT05. This control signal S2 is connected to the terminal pair BT02 and the rechargeable battery. This is a signal that controls the switching circuit BT05 to connect the group of elements.

[0325] Furthermore, the switching control circuit BT03 is connected to the switching circuit BT04, the switching circuit BT05, And based on the configuration of the transformer circuit BT07, between the terminal pair BT01 and the group of discharge battery cells, The terminals of the BT02 and the group of rechargeable battery cells are controlled to connect terminals of the same polarity. The system generates the official signal S1 and the control signal S2.

[0326] This section describes the operation of the switching control circuit BT03 in detail.

[0327] First, the switching control circuit BT03 measures the voltage of each of the multiple battery cells BT09. Then, the switching control circuit BT03, for example, switches the battery cell BT09 with a voltage above a predetermined threshold. High-voltage battery cells (high-voltage cells), BT09 battery cells with a voltage below a predetermined threshold, and low-voltage It is determined to be a battery cell (low-voltage cell).

[0328] Furthermore, various methods are used to determine whether a cell is high-voltage or low-voltage. This is possible. For example, the switching control circuit BT03 is the most important among the multiple battery cells BT09. Each battery cell BT09 is measured using the voltage of the highest or lowest voltage battery cell as a reference. 09 may also be used to determine whether it is a high-voltage cell or a low-voltage cell. In this case, the switching control circuit BT0 Step 3 determines whether the voltage of each battery cell BT09 is above a predetermined percentage of the reference voltage. By doing so, it is possible to determine whether each battery cell BT09 is a high-voltage cell or a low-voltage cell. Then, based on this determination, the switching control circuit BT03 switches between the discharge battery cell group and the charging battery group. Determine the battery cell group.

[0329] Note that within multiple BT09 battery cells, high-voltage and low-voltage cells are mixed in various states. It is possible. For example, the switching control circuit BT03 is used when high-voltage cells and low-voltage cells are mixed together. The portion where the most high-voltage cells are connected in series is designated as the discharge battery cell group. The switching control circuit BT03 charges the portion where the most low-voltage cells are connected in series. This is a group of battery cells. Furthermore, the switching control circuit BT03 is used for batteries that are close to being overcharged or over-discharged. Cell BT09 is preferentially selected as either a discharge battery cell group or a recharge battery cell group. That's good too.

[0330] Here, an example of the operation of the switching control circuit BT03 in this embodiment will be explained using Figure 35. To clarify, Figure 35 is a diagram illustrating an example of the operation of the switching control circuit BT03. For the sake of explanation, Figure 35 shows an example where four BT09 battery cells are connected in series. explain.

[0331] First, in the example shown in Figure 35(A), the voltages of battery cells a through d are defined as voltages Va through Vd. This shows the case where Va=Vb=Vc>Vd. In other words, three consecutive high Voltage cells a through c and one low-voltage cell d are connected in series. In this case, switching The control circuit BT03 determines three consecutive high-voltage cells a to c as a discharge battery cell group. The switching control circuit BT03 also determines the low-voltage cell d as part of the rechargeable battery cell group. ru.

[0332] Next, the example in Figure 35(B) shows the case where Vc > Va = Vb >> Vd. In other words, two consecutive low-voltage cells a and b, one high-voltage cell c, and one over-discharge A nearby low-voltage cell d is connected in series. In this case, the switching control circuit BT03 The high-voltage cell c is determined to be the discharge battery cell group. Furthermore, the switching control circuit BT03 is... Because low-voltage cell d is close to over-discharge, instead of using the two consecutive low-voltage cells a and b, Voltage cell d is given priority as the group of rechargeable battery cells.

[0333] Finally, the example in Figure 35(C) shows the case where Va > Vb = Vc = Vd. In other words, one high-voltage cell a is connected in series with three consecutive low-voltage cells b through d. In this case, the switching control circuit BT03 switches the high-voltage cell a to the discharge battery cell group. The decision is made. Furthermore, the switching control circuit BT03 charges three consecutive low-voltage cells b through d. This will be determined as a group of battery cells.

[0334] The switching control circuit BT03 is determined as shown in the examples in Figures 35(A) to (C) above. Based on the results, information indicating the group of discharge battery cells to which the switching circuit BT04 is connected is set. The signal control S1 and information indicating the group of rechargeable battery cells to which the switching circuit BT05 is connected The set control signal S2 is sent to switching circuits BT04 and BT05. Output each separately.

[0335] The above is a detailed explanation of the operation of the switching control circuit BT03.

[0336] The switching circuit BT04 responds to the control signal S1 output from the switching control circuit BT03. Then, the destination of the terminal pair BT01 is determined by the switching control circuit BT03, which is the discharge battery. Set it to a group of cells.

[0337] Terminal pair BT01 is composed of the paired terminals A1 and A2. Switching circuit BT0 4. Of these terminals A1 and A2, one is the upstream (high) of the group of discharged battery cells. Connect the positive terminal of battery cell BT09 located on the potential side, and the other end within the group of discharge battery cells. By connecting to the negative terminal of the battery cell BT09, which is located furthest downstream (low potential side), the terminal Set the connection destination for the child BT01. Note that the switching circuit BT04 is set to control signal S1. The location of the discharge battery cells can be recognized using the collected information.

[0338] The switching circuit BT05 responds to the control signal S2 output from the switching control circuit BT03. Then, the connection destination of terminal pair BT02 is determined by the switching control circuit BT03 to the rechargeable battery. Set it to a group of cells.

[0339] Terminal pair BT02 consists of the paired terminals B1 and B2. Switching circuit BT0 5. Of these terminals B1 and B2, one is the upstream (high) of the rechargeable battery cell group. Connect the positive terminal of battery cell BT09 located on the potential side, and the other end within the group of rechargeable battery cells. By connecting to the negative terminal of the battery cell BT09, which is located furthest downstream (low potential side), the terminal Set the connection destination for the child BT02. Note that the switching circuit BT05 is set to control signal S2. The information obtained can be used to recognize the location of the battery cell group.

[0340] Figures 36 and 36 show circuit diagrams illustrating example configurations of switching circuits BT04 and BT05. This is shown in 37.

[0341] In Figure 36, the switching circuit BT04 consists of multiple transistors BT10 and bus BT11 It also has BT12. Bus BT11 is connected to terminal A1. Terminal 12 is connected to terminal A2. Multiple transistors BT10 are either source or drain. One of them is connected to buses BT11 and BT12 alternately, one after the other. Furthermore, the source or drain of each of the multiple transistors BT10 is connected to two adjacent ones. It is connected between the BT09 battery cells.

[0342] Of the multiple transistors BT10, the transistor BT10 located at the very top The other end of the source or drain is the positive terminal of battery cell BT09, which is located at the uppermost part of battery section BT08. It is connected to the polarity terminal. Also, it is located at the downstream end of the multiple transistors BT10. The source or drain of transistor BT10 is located at the furthest downstream end of the battery section BT08. It is connected to the negative terminal of the BT09 battery cell.

[0343] The switching circuit BT04 provides control signals S1 to the gates of multiple transistors BT10. Accordingly, one of the multiple transistors BT10 connected to bus BT11, and bus One of the multiple transistors BT10 connected to BT12 is set to conduction. This connects the discharge battery cell group and the terminal pair BT01. The positive terminal of battery cell BT09, which is located in the uppermost part of the cell group, is terminal A1 of the terminal pair or It is connected to either of the A2 cells. It is also the battery located at the downstream end of the discharge battery cell group. The negative terminal of cell BT09 is the other terminal of the terminal pair, either A1 or A2, i.e., the positive terminal. It connects to the terminal that is not connected to the child.

[0344] It is preferable to use an OS transistor for transistor BT10. Because the off-current is small, the amount of charge leaking from battery cells that do not belong to the discharge battery cell group is small. This reduces the amount of power required, thus suppressing the decrease in capacity over time. Furthermore, OS transistors... Dielectric breakdown is less likely to occur when high voltage is applied. Therefore, the output voltage of the discharge battery cell group is high. Even if you hear it, the transistor BT10, which is in a non-conductive state, is connected to the battery cell BT09 and terminals. It is possible to isolate it from BT01.

[0345] Furthermore, in Figure 36, the switching circuit BT05 consists of multiple transistors BT13 and a current control It has a switch BT14, a bus BT15, and a bus BT16. Buses BT15 and B T16 is positioned between multiple transistors BT13 and the current control switch BT14. The source or drain of each of the multiple transistors BT13 is alternated every other one. They are connected to buses BT15 and BT16. Also, multiple transistors BT13 The source or drain of the other is connected between two adjacent battery cells BT09, respectively. It is being done.

[0346] Of the multiple transistors BT13, the transistor BT13 located at the very top The other end of the source or drain is the positive terminal of battery cell BT09, which is located at the uppermost part of battery section BT08. It is connected to the polarity terminal. Also, it is located at the downstream end of the multiple transistors BT13. The source or drain of transistor BT13 is located at the furthest downstream end of the battery section BT08. It is connected to the negative terminal of the BT09 battery cell.

[0347] Transistor BT13 uses an OS transistor, similar to transistor BT10. It is preferable that the OS transistor has a small off-current and therefore does not belong to the rechargeable battery cell group. This reduces the amount of charge leaking from the battery cell and suppresses the decrease in capacity over time. Yes, it is possible. Furthermore, OS transistors are less prone to dielectric breakdown when high voltage is applied. Therefore... Even if the voltage for charging the battery cells is high, transistor B will remain in a non-conductive state. T13 can be used to insulate the battery cell BT09 to which it is connected from the terminal pair BT02. .

[0348] The current control switch BT14 has a switch pair BT17 and a switch pair BT18. One end of the switch to BT17 is connected to terminal B1. Also, the switch to BT17 The other end is branched by two switches; one switch is connected to bus BT15, and the other... The switch is connected to bus BT16. One end of the switch to BT18 is connected to terminal B2. They are connected. Also, the other end of the switch to BT18 is branched by two switches, One switch is connected to bus BT15, and the other switch is connected to bus BT16. ru.

[0349] The switches in switch pair BT17 and switch pair BT18 are transistor BT1 Similar to transistor 0 and transistor BT13, it is preferable to use an OS transistor.

[0350] The switching circuit BT05 controls the transistor BT13 and the current control according to the control signal S2. By controlling the on / off state combination of the BT14 switch, the rechargeable battery cells Connect the group to the terminal pair BT02.

[0351] The switching circuit BT05, as an example, connects the rechargeable battery cell group and terminal pair BT as follows. Connect to 02.

[0352] The switching circuit BT05 provides control signals S2 to the gates of multiple transistors BT13. Accordingly, connect to the positive terminal of battery cell BT09, which is the most upstream battery cell in the rechargeable battery cell group. The transistor BT13 is made conductive. Also, the switching circuit BT05 is multiple In accordance with the control signal S2 applied to the gates of the transistors BT13, among the group of rechargeable battery cells Transistor BT1 is connected to the negative terminal of battery cell BT09, which is located furthest downstream. Connect 3 to a conductive state.

[0353] The polarity of the voltage applied to terminal pair BT02 is the same as that of the discharge battery cell connected to terminal pair BT01. This can vary depending on the group and the configuration of the BT07 transformer circuit. Also, the charging of the battery cell group To allow current to flow in one direction, terminals of the same polarity must be connected between the BT02 terminal pair and the group of rechargeable battery cells. They need to be connected. Therefore, the current control switch BT14 is controlled by the control signal S2. Depending on the polarity of the voltage applied to terminal pair BT02, switch pair BT17 and switch pair B The T18 is controlled to switch between different connection destinations.

[0354] As an example, a voltage is applied to terminal pair BT02 such that terminal B1 is positive and terminal B2 is negative. Let's explain by listing the conditions under which it is applied. At this time, the battery cell BT0, which is the downstream of the battery unit BT08 If 9 is a group of rechargeable battery cells, the switch to BT17 will, by the control signal S2, control the battery It is controlled to connect to the positive terminal of cell BT09, i.e., switch to BT17. The switch connected to bus BT16 is turned ON, and the switch is connected to bus BT17. The switch connected to 15 is turned off. Meanwhile, the switch to BT18 receives the control signal S. According to 2, it is controlled to connect to the negative terminal of the battery cell BT09. That is, The switch connected to the BT15 bus of the switch to BT18 is turned ON, and the switch to The switch connected to the BT16 bus of BT18 is turned off. In this way, the terminal Between the BT02 and the rechargeable battery cell group, terminals with the same polarity are connected. The direction of the current flowing from the terminal pair BT02 is controlled to charge the battery cells. To be controlled.

[0355] Furthermore, the current control switch BT14 is not the switching circuit BT05, but the switching circuit B It may be included in T04. In this case, the current control switch BT14 and the control signal S1 are in response to each other. By controlling the polarity of the voltage applied to terminal pair BT01, the voltage applied to terminal pair BT02 is controlled. It controls the polarity of the applied voltage. The current control switch BT14 controls the terminals of BT0 The direction of the current flowing from the battery cell group is controlled from point 2.

[0356] Figure 37 shows the configuration of switching circuits BT04 and BT05, which differs from that of Figure 36. This is a circuit diagram illustrating an example.

[0357] In Figure 37, the switching circuit BT04 consists of multiple transistor pairs BT21 and bus BT2 It has 4 and bus BT25. Bus BT24 is connected to terminal A1. BT25 is connected to terminal A2. One end of the multiple transistor pair BT21 is connected to... The signal branches off from transistors BT22 and BT23. Either the source or drain of the BT22 is connected to the BT24 bus. Either the source or drain of the converter BT23 is connected to the bus BT25. The other ends of each pair of transistors are connected between two adjacent battery cells BT09. It is done. Furthermore, among the multiple transistor pairs BT21, the transistor located at the very top The other end of the BT21 connector is the positive terminal of the battery cell BT09, which is located at the uppermost part of the battery section BT08. It is connected to the downstream transistor among the multiple transistor pairs BT21. The other end of the converter pair BT21 is connected to the negative terminal of battery cell BT09, which is located at the downstream end of the battery section BT08. It is connected to the terminal.

[0358] The switching circuit BT04 controls transistor BT22 and transistor BT22 in response to the control signal S1. By switching the conduction / non-conduction state of BT23, the relationship between the transistor and BT21 is Switch the connection destination to either terminal A1 or terminal A2. For details, see the transistor. If BT22 is conducting, transistor BT23 will be non-conducting, and its connection point is Terminal A1. On the other hand, if transistor BT23 is conducting, then transistor BT2 Terminal 2 becomes non-conductive, and its connection point is terminal A2. Transistor BT22 and Transistor Which of the BT23 resistors becomes conductive is determined by the control signal S1.

[0359] To connect terminal pair BT01 to the group of discharge battery cells, two transistor pairs BT21 are used. It is used. In detail, the connection of two transistors to BT21 is based on the control signal S1. Once the destinations are determined, the group of discharge battery cells and the terminal pair BT01 are connected. The connections of the two transistor pairs BT21 are such that one is to terminal A1 and the other is to terminal A1. It is controlled by the control signal S1 so that it becomes child A2.

[0360] The switching circuit BT05 consists of multiple transistor pairs BT31 and buses BT34 and B Bus BT34 has T35. Bus BT34 is connected to terminal B1. Bus BT35 is , connected to terminal B2. One end of each pair of transistors BT31 is connected to the transistor It branches off from transistor BT32 and transistor BT33. Transistor BT32 One of the branches is connected to bus BT34. Also, transistor BT33 One of the branched ends is connected to bus BT35. Also, multiple transistors are paired with BT35. The other end of 1 is connected between two adjacent battery cells BT09. Of the number of transistor pairs BT31, the other end of the upstream transistor pair BT31 is It is connected to the positive terminal of battery cell BT09, which is located at the uppermost part of the battery section BT08. Furthermore, among the multiple pairs of transistors BT31, the pair of transistors BT31 located at the furthest downstream The other end is connected to the negative terminal of battery cell BT09, which is located at the downstream end of battery section BT08. ru.

[0361] The switching circuit BT05 switches between transistors BT32 and transistors according to the control signal S2. By switching the conduction / non-conduction state of BT33, the relationship between the transistor and BT31 is Switch the connection destination to either terminal B1 or terminal B2. For details, see the transistor. If BT32 is conducting, transistor BT33 will be non-conducting, and its connection point is Terminal B1. Conversely, if transistor BT33 is conducting, then transistor BT3 Terminal 2 becomes non-conductive, and its connection point is terminal B2. Transistor BT32 and Transistor Which of the BT33 resistors becomes conductive is determined by the control signal S2.

[0362] To connect the terminal pair BT02 to the battery cell group, two transistor pairs BT31 are used. It is used. In detail, the connection of two transistors to BT31 is based on the control signal S2. Once the destinations are determined, the rechargeable battery cell group and the terminal pair BT02 are connected. The connections of the two transistor pairs BT31 are such that one is to terminal B1 and the other is to the terminal It is controlled by the control signal S2 to become child B2.

[0363] Furthermore, the connections of the two transistor pairs BT31 are applied to the terminal pair BT02. It is determined by the polarity of the applied voltage. Specifically, terminal B1 is the positive terminal and terminal B2 is the negative terminal. If such a voltage is applied to terminal pair BT02, then the upstream transistor pair BT31 This results in transistor BT32 becoming conductive and transistor BT33 becoming non-conductive. Thus, it is controlled by the control signal S2. On the other hand, the downstream transistor pair BT31 is The control is set such that transistor BT33 is in a conductive state and transistor BT32 is in a non-conductive state. It is controlled by signal S2. Also, terminal B1 is the negative terminal and terminal B2 is the positive terminal. When voltage is applied to terminal pair BT02, the upstream transistor pair BT31 is Transistor BT33 becomes conductive and transistor BT32 becomes non-conductive. It is controlled by the control signal S2. On the other hand, the downstream transistor pair BT31 is Control signal S such that transistor BT32 is in a conducting state and transistor BT33 is in a non-conducting state. Controlled by 2. In this way, between the terminal pair BT02 and the group of rechargeable battery cells, Terminals with opposite polarity are connected. Then, the direction of the current flowing from terminal to terminal BT02 is, The system is controlled to charge the battery cells.

[0364] The transformer control circuit BT06 controls the operation of the transformer circuit BT07. Transformer control circuit BT06 This refers to the number of BT09 battery cells included in the discharge battery cell group and the number of BT09 battery cells included in the recharge battery cell group. Based on the number of battery cells BT09, a transform signal S3 is generated to control the operation of the transformer circuit BT07. It is generated and output to the transformer circuit BT07.

[0365] Note that the number of BT09 battery cells included in the discharge battery cell group is the same as the number of BT09 battery cells included in the recharge battery cell group. If the number of battery cells exceeds the number of BT09 cells, the charging power will be excessively large for the battery cell group. It is necessary to prevent pressure from being applied. Therefore, the voltage transformer control circuit BT06 controls the charging power The transformer circuit BT07 reduces the discharge voltage (Vdis) to a level that allows the battery cells to be charged. It outputs a transform signal S3 to control the voltage.

[0366] Furthermore, the number of BT09 battery cells included in the discharge battery cell group is the same as the number of BT09 battery cells included in the recharge battery cell group. If the number of BT09 battery cells is less than or equal to the number of BT09 battery cells, the amount of charge required to charge the battery cell group will be used. It is necessary to ensure sufficient voltage. Therefore, the transformer control circuit BT06 overloads the battery cell group. Transformer circuit B is configured to increase the discharge voltage (Vdis) within a range where no excess charging voltage is applied. Outputs a transformer signal S3 to control T07.

[0367] Note that the voltage value that constitutes excessive charging voltage is the BT09 battery cell used in the BT08 battery unit. The specifications can be determined in consideration of the product specifications, etc. Furthermore, the BT07 transformer circuit can be used for both step-up and step-down voltage conversion. The applied voltage is then applied to the terminal pair BT02 as the charging voltage (Vcha).

[0368] Here, an example of the operation of the transformer control circuit BT06 in this embodiment is shown in Figures 38(A) to (C) This will be explained using Figures 35(A) to (C). This section describes an example of the operation of the BT06 transformer control circuit, which corresponds to a group of electric battery cells and a group of rechargeable battery cells. This is a conceptual diagram for the purpose of [doing something]. Figures 38(A) to (C) show the battery control unit BT41. As shown above, the battery control unit BT41 has terminal pair BT01 and terminal pair BT02, switching control circuit BT03, switching circuit BT04, and switching circuit BT It consists of 05, the transformer control circuit BT06, and the transformer circuit BT07.

[0369] In the example shown in Figure 38(A), as explained in Figure 35(A), three consecutive high-voltage Voltage cells a through c and one low-voltage cell d are connected in series. In this case, see Figure 35( As explained using A), the switching control circuit BT03 discharges high-voltage cells a to c. The battery cell group is determined, and the low-voltage cell d is determined to be the rechargeable battery cell group. Then, the voltage is transformed. The control circuit BT06 is based on the number of battery cells BT09 included in the discharge battery cell group. Based on the ratio of the number of BT09 battery cells included in the rechargeable battery cell group, the discharge voltage (Vd Calculate the conversion ratio N from is to charging voltage (Vcha).

[0370] Note that the number of BT09 battery cells included in the discharge battery cell group is the same as the number of BT09 battery cells included in the recharge battery cell group. If the number of battery cells exceeds the number of BT09 cells, the discharge voltage is not transformed and is applied to the terminal pair BT02. When applied as is, the battery cell BT09 included in the rechargeable battery cell group is transmitted via terminal pair BT02. This could result in an excessive voltage being applied. Therefore, in cases like the one shown in Figure 38(A) Next, we will reduce the charging voltage (Vcha) applied to the terminal pair BT02 to a level lower than the discharge voltage. It is necessary. Furthermore, in order to charge the battery cell group, the charging voltage is the battery cell group The total voltage of the BT09 battery cells included must be greater than that of the transformer control circuit. BT06 is based on the number of BT09 battery cells included in the discharge battery cell group, and the charge The conversion ratio N is set to be greater than the ratio of the number of BT09 battery cells included in the battery cell group.

[0371] The voltage transformer control circuit BT06 is based on the number of battery cells BT09 included in the discharge battery cell group. When this is done, the conversion ratio N is applied to the ratio of the number of BT09 battery cells included in the group of rechargeable battery cells. It is preferable to increase it by about 1 to 10%. At this time, the charging voltage should be different from the voltage of the battery cell group. Although the voltage will also increase, in reality the charging voltage will be equal to the voltage of the battery cell group. However, The voltage control circuit BT06 adjusts the voltage of the battery cell group to be equal to the charging voltage according to the conversion ratio N. This will supply current to charge the battery cells. This current is supplied by the BT06 transformer control circuit. The value set will be used.

[0372] In the example shown in Figure 38(A), the number of battery cells BT09 included in the discharge battery cell group is With 3 units, and since there is 1 BT09 battery cell in the rechargeable battery cell group, the voltage transformation control cycle For circuit BT06, the conversion ratio N is calculated to be slightly larger than 1 / 3. Then, the voltage transformation control cycle The circuit BT06 converts the discharge voltage into a charging voltage by stepping down the discharge voltage according to the conversion ratio N, and the resulting transform signal S The signal 3 is output to the transformer circuit BT07. Then, the transformer circuit BT07 responds to the transformer signal S3. The transformed charging voltage is applied to terminal pair BT02. The BT09 battery cell included in the rechargeable battery cell group is charged by the charging voltage.

[0373] Furthermore, in the examples shown in Figures 38(B) and 38(C), the conversion ratio is the same as in Figure 38(A). N is calculated. In the examples shown in Figures 38(B) and 38(C), the discharge battery cell group is The number of BT09 battery cells is less than or equal to the number of BT09 battery cells included in the rechargeable battery cell group. Therefore, the conversion ratio N will be 1 or greater. Thus, in this case, the voltage transformer control circuit BT06 is A transform signal S3 is output, which increases the discharge voltage and converts it into a charging voltage.

[0374] The transformer circuit BT07 applies a discharge voltage to the terminal pair BT01 based on the transformer signal S3. It converts the voltage to a charging voltage. Then, the transformer circuit BT07 converts the charged voltage to the terminals BT Apply to 02. Here, the transformer circuit BT07 is between terminal pair BT01 and terminal pair BT02. It is electrically isolated. As a result, the transformer circuit BT07 is the most in the group of discharge battery cells. The absolute voltage of the negative terminal of battery cell BT09 located downstream, and the lowest voltage among the group of rechargeable battery cells. This prevents short circuits caused by the difference in absolute voltage between the negative terminal of battery cell BT09 located in the current. Furthermore, as described above, the transformer circuit BT07 transforms the group of discharge battery cells based on the transformer signal S3. The discharge voltage, which is the total voltage, is converted to the charge voltage.

[0375] Furthermore, the BT07 transformer circuit is, for example, an isolated DC (Direct Current)-D transformer. A C converter or the like can be used. In this case, the transformer control circuit BT06 is an isolated DC converter. -The signal that controls the on / off ratio (duty cycle) of the DC converter is the transform signal S3. By outputting this signal, the charging voltage converted by the BT07 transformer circuit is controlled.

[0376] Isolated DC-DC converters include flyback, forward, and RCC types. (Ringing Choke Converter) method, push-pull method, half Bridge and full-bridge designs exist, but they depend on the desired output voltage level. The appropriate method will then be selected.

[0377] Figure 39 shows the configuration of the BT07 transformer circuit using an isolated DC-DC converter. The DC-DC converter BT51 has a switch section BT52 and a transformer section BT53. The BT52 switch unit switches the operation of the isolated DC-DC converter on and off. It is a switch, for example, a MOSFET (Metal-Oxide-Semiconductor) Field-effect transistors and bipolar transistors This is achieved using a switch, etc. Furthermore, the switch unit BT52 is connected to the transformer control circuit BT06. Based on the transform signal S3 that controls the on / off ratio, an isolated DC-DC converter is used. The ON and OFF states of BT51 are periodically switched. Note that the switch unit BT52 is... Various configurations are possible depending on the type of isolated DC-DC converter used. Part BT53 converts the discharge voltage applied from terminal pair BT01 into a charging voltage. The transformer section BT53 operates in conjunction with the on / off state of the switch section BT52, and The discharge voltage is converted to a charging voltage according to the on / off ratio. This charging voltage is used in the switch section BT. In a 52-period switching cycle, the longer the time spent in the ON state, the larger the value. The voltage is such that the ON state time is short during the switching cycle of the switch unit BT52. It becomes smaller. Note that when using an isolated DC-DC converter, the transformer section BT53 Within the structure, terminal pair BT01 and terminal pair BT02 can be isolated from each other.

[0378] The processing flow of the energy storage device BT00 in this embodiment will be explained using Figure 40. Figure 4 0 is a flowchart showing the processing flow of the energy storage device BT00.

[0379] First, the energy storage device BT00 acquires the voltage measured for each of the multiple battery cells BT09. Step S101). Then, the energy storage device BT00 equalizes the voltage of multiple battery cells BT09. It is determined whether the start condition for the operation is met (step S102). This start condition is, For example, the difference between the maximum and minimum voltage measured for each of the multiple battery cells BT09 is predetermined This can be determined by whether or not it is above a threshold, etc. If this starting condition is not met, (step S 102:NO), Since the voltage of each battery cell BT09 is balanced, storage The electrical device BT00 will not perform the subsequent processing. On the other hand, if the start condition is met (step S102:YES), the energy storage device BT00 performs a process to equalize the voltage of each battery cell BT09. The process is carried out. In this process, the energy storage device BT00 performs the following based on the measured voltage of each cell: It is determined whether each battery cell BT09 is a high-voltage cell or a low-voltage cell (step S103). Based on the determination result, the energy storage device BT00 determines the discharge battery cell group and the recharge battery cell group. Determine (step S104). Furthermore, the energy storage device BT00 determines the group of discharged battery cells. Control signal S1 sets the terminal pair BT01 as the connection destination, and the determined group of rechargeable battery cells is connected to the terminal A control signal S2 is generated to be set as the connection destination for the child BT02 (step S105). The BT00 unit receives the generated control signals S1 and S2 from the switching circuit BT04 and The output is sent to the switching circuit BT05. Then, the switching circuit BT04 sends the terminals The terminals BT01 and the group of discharge battery cells are connected, and the switching circuit BT05 switches the terminals BT0 2 is connected to the group of discharge battery cells (step S106). Also, the energy storage device BT00 is The number of BT09 battery cells included in the discharge battery cell group and the number of BT09 battery cells included in the recharge battery cell group Based on the number of BT09 units, a transform signal S3 is generated (step S107). Based on the voltage transformation signal S3, the energy storage device BT00 applies a discharge voltage to the terminal pair BT01. This is converted to a charging voltage and applied to the terminal pair BT02 (step S108). Charge is transferred from the group of battery cells to the group of rechargeable battery cells.

[0380] Also, in the flowchart of Figure 40, multiple steps are listed in order, but each step The execution order of the steps is not limited to the order in which they are listed.

[0381] As described above, according to this embodiment, when transferring charge from a group of discharge battery cells to a group of rechargeable battery cells Unlike the capacitor system, which temporarily stores charge from a group of discharge battery cells, the rechargeable battery cells... It does not require a configuration that releases to the group. This eliminates the charge transfer efficiency per unit time. The efficiency can be improved. Also, the switching circuits BT04 and BT05 Therefore, among the discharge battery cell group and the rechargeable battery cell group, the battery cells connected to the transformer circuit are individually selected. It can be switched to.

[0382] Furthermore, the transformer circuit BT07 controls the number of battery cells BT09 included in the discharge battery cell group. Based on the number of battery cells BT09 included in the rechargeable battery cell group, the terminal pair BT01 The applied discharge voltage is converted into a charging voltage and applied to the terminal pair BT02. This allows, Regardless of how the BT09 battery cells on the discharge and charge sides are selected, charge transfer proceeds without any problems. It can be achieved.

[0383] Furthermore, OS transistors are used for transistors BT10 and BT13. As a result, leakage occurs from battery cell BT09, which does not belong to the rechargeable battery cell group or the dischargeable battery cell group. This reduces the amount of charge that does not contribute to charging and discharging. The decrease in capacitance 9 can be suppressed. Also, OS transistors are Si transistors Compared to that, the variation in thermal properties is smaller. As a result, the temperature of the battery cell BT09 rises. However, normal operation such as switching between conductive and non-conductive states according to control signals S1 and S2 It can be made to work.

[0384] This embodiment can be implemented in appropriate combination with other embodiments. [Examples]

[0385] This embodiment describes an example of a method for producing a conductor as shown in Embodiment 1, and the physical properties of the obtained conductor. And its characteristics will be explained.

[0386] <Fabrication of conductive materials> A method for producing a conductor 201 according to one aspect of the present invention will be described.

[0387] First, prepare graphene oxide. Using scaly graphite as the raw material for graphene oxide, Mo Using the modified Hummers process, potassium permanganate and sulfur are used in the oxidation step. A material prepared using acid was used. After depositing silicon nitride on a silicon wafer... A solution of graphene oxide dispersed in water is applied, and the graphene oxide is observed using an optical microscope. From what I can gather, the flake size of graphene oxide is, for example, about 15 μm to 50 μm. Many of these were observed. Figures 53(A) to (C) show optical microscope images of graphene oxide. Here is an example.

[0388] Next, graphene oxide is dispersed in a solvent to prepare a graphene oxide dispersion. To 200 ml of a dispersion of ght% graphene oxide in water, add 600 ml of water. In addition, the mixture was stirred at 600 rpm for 12 hours to prepare dispersion A.

[0389] Next, using a graphene oxide dispersion as the raw material, graphene is processed by spray drying. A compound sheet (referred to as GO-1) is deposited. This is done in the chamber of the spray drying apparatus. GO-1 is deposited on the wall surface. Details are explained below.

[0390] A BUCHI B-290 mini spray dryer was used as the spray drying device. The inlet temperature was set to 160°C. The area near the nozzle was heated to a temperature of over 100°C. This is considered to be the case. Dispersion A is supplied to the nozzle of the spray dryer at a rate of approximately 65 ml / min. Dispersion A was then released from the nozzle along with nitrogen gas at a flow rate of 60 L / min into the chamber. It was supplied as a spray.

[0391] Dispersion A, supplied into the chamber as a spray, partially consists of graphene oxide powder. The film is collected in a collection container, and a portion of it is deposited as GO-1 on the inner wall 281a of the cylindrical chamber. Figure 41 shows a photograph of GO-1 with a film deposited on its inner wall.

[0392] Next, GO-1 is peeled off from the inner wall of the chamber. GO-1 consists of multiple overlapping oxidation cells. It contains graphene. The average thickness of GO-1 was 8.6 μm. (Approximately 10 cm square area) Within the region, 10 measurements were taken and the average was calculated. The obtained GO-1 XRD evaluation was... Electrical conductivity measurements were performed. The results will be described later. An example of a photograph of GO-1 is shown in Figure 42. Furthermore, an optical microscope image of GO-1 is shown in Figure 54(A), and a SEM image is shown in Figure 54(B).

[0393] Next, GO-1 was subjected to a reduction treatment to obtain a conductor. Here, the reduction treatment was performed under three conditions. The test was conducted. Of the obtained conductors, those subjected only to thermal reduction at 250°C were RGO- 1A, RGO-1B is the result of thermal reduction only at 300°C, and 250°C is the result of chemical reduction followed by 250°C. The product that underwent thermal reduction at °C is designated as RGO-1C. An example of a photograph of RGO-1C is shown in Figure 43. Furthermore, Figures 55(A) and (B) show optical microscope images of RGO-1A and RGO-1C. This proves true. Also, Figures 56(A) and (B) show SEM images of RGO-1A and RGO-1C. Show the image.

[0394] The reduction treatment reduces the graphene oxide present in GO-1, decreasing its oxygen content. RGO-1A to RGO-1C contain graphene compounds. Also, RGO-1A RGO-1C is a graphene compound sheet.

[0395] The conditions for chemical reduction will be explained. Ascorbic acid will be used as the reducing agent, and as the solvent... An 80% ethanol aqueous solution was used. Asco A reducing solution was prepared by adding 0.3375g of rubic acid and 0.078g of lithium hydroxide.

[0396] The obtained GO-1 was placed in a reducing solution and treated at 60°C for 3 hours to reduce it. After that, ethanol The cleaning was performed using a cleaning solution.

[0397] The conditions for thermal reduction will be explained. The heat treatment conditions are 250°C under a reduced pressure atmosphere of 1 kPa. The process was carried out for 0 hours. Through the above process, sheet-like conductive materials RGO-1A to RGO-1 C was obtained.

[0398] <Evaluation of conductors, etc.> Next, we will discuss the evaluation results of the physical properties and characteristics of GO-1, RGO-1A to RGO-1C. explain.

[0399] The electrical conductivity of the obtained samples was measured. Mitsubishi Chemical Analytec was used for the measurement of electrical conductivity. A Loresta-GP (model number: MCP-T610) manufactured by [manufacturer name] was used. The probe was MCP-TP0 Measurements were taken using 6P at room temperature.

[0400] The electrical conductivity of GO-1, RGO-1A, and RGO-1C is 0.0021, 4, respectively. The values ​​were 0.2, 6.3, and 25 [S / cm].

[0401] Next, XRD evaluation was performed. XRD evaluation of GO-1, RGO-1A, and RGO-1B. The results are shown in Figures 44(A), (B), and (C), respectively. Here, RGO-1A and RGO For -1B, samples were prepared using two different lots, as shown in Figure 44(B). And shown in (C) with solid and dashed lines.

[0402] In Figures 44(A), (B), and (C), near 9°, 22°, and 23°, respectively, A groove was observed, with average interlayer distances of approximately 0.98 nm, 0.40 nm, and 0. It is suggested to be 0.39 nm. Here, "nearby" refers, for example, to "2θ" obtained by XRD evaluation. The angle should be within a range of ±0.7° or ±0.5°. In other words, close to 9° "Nearby" refers to, for example, the range of 8.3° to 9.7°, or 8.5° to 9.5°. It is within the range.

[0403] Next, we performed an XPS evaluation. First, we show the results for GO-1.

[0404] When the elemental quantitative values ​​of GO-1 were evaluated, carbon, oxygen, sulfur, and nitrogen were found to be... The values ​​were 63.7, 33.5, 2.3, and 0.6 (in atomic%), respectively.

[0405] The C1s spectrum of carbon is shown in Figure 45(A), and the O1s spectrum of oxygen is shown in Figure 45(B). The S2p spectrum of sulfur is shown in Figure 46(A), and the N1s spectrum of nitrogen is shown in Figure 46(B). These will be shown.

[0406] Next, the XPS evaluation results for RGO-1A and RGO-1C are shown.

[0407] When the elemental quantitative values ​​of RGO-1A were evaluated, carbon, oxygen, sulfur, and nitrogen were found to be present. The values ​​were 80.7, 15.8, 1.4, and 2.1 (in atomic%), respectively. .

[0408] When the elemental quantitative values ​​of RGO-1C were evaluated, carbon, oxygen, sulfur, and nitrogen were found to be present. The values ​​were 89.5, 9.2, 0.2, and 1.2 (in atomic%), respectively.

[0409] For RGO-1A and RGO-1C, the carbon c1s spectra are shown in Figure 47(A). The O1s spectrum of oxygen is shown in Figure 47(B), and the S2p spectrum of sulfur is shown in Figure 48(A). The N1s spectra of nitrogen are shown in Figure 48(B), respectively. [Examples]

[0410] This embodiment describes a method for producing a conductor according to one aspect of the present invention, as well as its physical properties and characteristics. I will reveal it.

[0411] <Processing using solvents> The graphene compound sheet GO-1 obtained in Example 1 was coated with a solvent. In practice, NMP is dropped onto GO-1, and then coated using a blade with a 100 μm gap. It was then laid. Afterwards, the solvent was evaporated (the graphene compound sheet obtained by solvent treatment was used). (This was referred to as GO-2). NMP was used as the solvent.

[0412] <Reduction> Next, a reduction treatment was performed on GO-2. The reduction treatment was performed under two conditions. 1 The second condition involves heat treatment at 250°C for 10 hours, resulting in RGO-2A. The material that has undergone heat treatment at 300°C for 10 hours is designated as RGO-2B.

[0413] <Evaluation of conductors, etc.> Next, we will discuss the evaluation results of the physical properties and characteristics of GO-2, RGO-2A, and RGO-2B. explain.

[0414] The electrical conductivity of RGO-2A and RGO-2B was 86 and 101 [S / cm], respectively. Furthermore, the electrical conductivity of GO-2 fell below the lower limit of measurement.

[0415] The XRD evaluation results for GO-2 and RGO-2A are shown in Figures 49(A) and (B).

[0416] In Figure 49(A), a peak was observed near 8°, and there was also a peak near 16°. A distinct peak is observed. The interlayer distance at the peak is approximately 1.1 nm and approximately 0.50 nm. This suggests something.

[0417] Furthermore, a peak was observed near 25° in Figure 49(B), and the average interlayer distance was approximately 0.3 It is suggested to be 6nm.

[0418] Here, regarding GO-1 prepared in Example 1 and GO-2 prepared in this example, FT - The results of the IR evaluation are shown in Figure 50(A). The dashed line shows the results for GO-1, and the solid line shows the results for GO-2. . The FT-IR method and measurement conditions are as follows: The measurement method is Attenuated Total Using reflection (total internal reflection measurement), the detector detects cadmium telluride mercury. It was used as a vessel.

[0419] As shown in Figure 50(A), GO-1 has CO bonds, C=C bonds and C=O bonds. The wave frequencies that each is thought to suggest are 1250 to 1000 cm. -1 , 1620-168 0cm -1 and 1750 to 1650 cm -1 A peak was observed in the range of [this range]. In contrast, In GO-2, changes were observed in the peak intensity ratio and position, and also at 1640 cm. -1 Nearby Stronger peaks have been observed. Also, GO-1 recorded 1045cm. -1 P A peak was observed. Possible attributions to this peak include, for example, the involvement of sulfur compounds. I believe so.

[0420] After applying NMP and drying, GO-2 showed, according to the FT-IR evaluation results, for example, CO bonding. This suggests that the types and concentrations of functional groups have changed, such as a decrease in the amount of compound. The distance between them may be increasing. Also, elements such as nitrogen may be located between the layers, forming interlayer compounds. This could potentially be achieved. Figure 50(B) shows GO-2 at 3000 cm -1 Expand the neighborhood The diagram below shows 2880cm. -1 Nearby and 2950cm -1 A peak is observed nearby, CH This suggests a binding relationship. For example, it is thought that H derived from NMP may be involved. It is. [Examples]

[0421] In this example, RGO-1A and RGO-1B prepared in Example 1 were used as electrodes. We manufactured a battery.

[0422] <Battery fabrication and evaluation> A rechargeable battery is fabricated using RGO-1A or RGO-1B as the electrode and lithium metal as the counter electrode. For evaluating the characteristics, a coin-shaped CR2032 type (20mm diameter, 3.2mm height) was used. A battery was used. Polypropylene was used as the separator. Ethylene carbohydrate was used as the electrolyte. Mix ionate (EC) and diethyl carbonate (DEC) in a volume ratio of 1:1. Dissolve lithium hexafluoride phosphate (LiPF6) at a concentration of 1 mole / liter in the mixed solution. The following was used. The positive electrode and negative electrode were made of stainless steel (SUS). I used that.

[0423] Next, the fabricated battery was charged and discharged. The measurement temperature was set to 25°C. Charging was performed as follows: Constant current charging was performed with a current density of 30 mA / g and an upper limit of 4.8 V. Furthermore, the discharge is performed using a constant current discharge with a current density of 30 mA / g per unit weight and a lower limit of 2V. went.

[0424] The charge and discharge characteristics of RGO-1A and RGO-1B are shown in Figures 51(A) and (B). The lines represent the samples shown as solid lines in Figures 44(B) and (C), and the dashed lines represent the samples shown as solid lines in Figure 44(B) and (C). In (C), the dashed lines correspond to the respective samples. Here, the vertical axis is voltage, and the horizontal axis is This indicates the volume per unit weight of RGO-1A or RGO-1B.

[0425] As shown in Figures 51(A) and (B), good charge and discharge characteristics were obtained.

[0426] Here, during charging and discharging, conductors such as RGO-1A and RGO-1B undergo a redox reaction. This is thought to contribute to the high capacity. As a result of charging and discharging the energy storage device, Insertion and detachment of anions and cations into the electrochemical body 201 may be occurring. The insertion and removal of anions and cations may cause oxidation-reduction reactions. The cations include lithium ions and ions other than lithium ions present in the electrolyte. For example, on the surface of the sheet-like conductor, a decomposition product of the electrolyte, such as L It is possible that i2CO3 and Li2O are precipitating, and an electrochemical reaction is occurring due to peroxide ions. I believe that there is. [Examples]

[0427] In this embodiment, the GO-1 manufactured in Example 1 is used as the current collector, and in Embodiment 2 An example of an electrode was fabricated.

[0428] <Synthesis of Lithium Manganese Composite Oxides> Using the active material shown in Embodiment 2 as raw materials, Li2CO3, MnCO3, and NiO are used. The ratios are Li2CO3:MnCO3:NiO = 0.84:0.8062:0.318. It was mixed with nickel. Then, it was calcined at 1000°C to produce a lithium manganese composite containing nickel. Sample A, which is an oxide, was prepared.

[0429] <Covering> Next, a dispersion of graphene oxide was prepared. Water was used as the solvent. The concentration of graphene oxide was I made it so that it would be 2weight%.

[0430] In a dispersion of graphene oxide, an amount is obtained in which the graphene oxide content is 6 g. 300g of sample A was added and mixed to obtain solution A. Then, solution A was subjected to 5°C under reduced pressure. Mixture B was obtained by heat treatment at 0°C.

[0431] Next, heat-treated mixture B is added to the reducing solution and heat-treated at 60°C for 3 hours to obtain solution C. Obtained. As the reducing solution, ascorbic acid was used as the reducing agent, and a solvent of 80% by volume was used. Using an aqueous ethanol solution, a concentration of 3.90 weight% of lithium hydroxide was used relative to sample A. M was added, and the concentration of ascorbic acid was set to 16.87 weight%t relative to sample A.

[0432] Next, solution C was recovered using a centrifuge to obtain mixture D. Then, mixture D was mortared. The mixture D was crushed, and the crushed mixture D was heat-treated at 170°C for 10 hours under reduced pressure, and sample E was prepared. Sample E has a lithium manganese composite oxide, and the lithium manganese composite oxide It contains nickel, and the surface of the lithium manganese composite oxide is coated with a graphene compound. It is being done.

[0433] <Electrode fabrication> Next, sample E, AB, and PVDF were mixed with NMP to prepare mixture F. The composition of F was set to sample E:AB:PVDF = 90:5:5 (weight%). Next, layer Mixture F, which results in 102, was applied to GO-1. Then, heat treatment was performed at 80°C for 30 minutes. The MP was vaporized. Then, the electrodes were pressed using a roll press machine. After that, Furthermore, a heat treatment is performed at 250°C for 10 hours, and a layer 102 is placed on the heat-treated GO-1. An electrode G was obtained. Here, for the heat-treated GO-1, the conductor shown as an example in Embodiment 1 Refer to the description of 201. The heat-treated GO-1 will henceforth be referred to as conductor 201. To include.

[0434] Furthermore, the mixture F is applied to the aluminum foil, and then the NMP is volatilized, pressed, and so The subsequent heat treatment was performed under the same conditions as for Electrode G, to fabricate Electrode H.

[0435] <TEM Observation> A TEM photograph of the cross-section of Electrode G is shown in Figure 57. Further, a photograph observed at a higher magnification is shown in Figure 5 8.

[0436] <Electrode Evaluation> A storage battery was fabricated using the obtained Electrode G and Electrode H. The counter electrode was lithium metal . For characteristic evaluation, a CR2032 type (diameter 20 mm, height 3.2 mm) coin-type storage battery was used. Polypropylene was used for the separator. For the electrolyte, ethylene carbo nate (EC) and diethyl carbonate (DEC) were mixed at a volume ratio of 1:1 Lithium hexafluorophosphate (LiPF6) was dissolved in the mixed solution at a concentration of 1 mol / liter was used. As the positive electrode can and negative electrode can, those formed of stainless steel (SUS) were used. Here, per unit area, the weight ratio of Sample E to Conductor 201 in Electrode G was approximately Sample E : Conductor 201 = 1 : 0.54.

[0437] Next, charging and discharging of the fabricated storage battery were performed. The measurement temperature was set to 25°C. For charging, the current density per weight of Sample E was set to 30 mA / g, and constant current charging was performed with an upper limit of 4.8 V . For discharging, constant current discharging was performed at 30 mA / g with a lower limit of 2 V.

[0438] The charge-discharge characteristics of the storage batteries using Electrode G and Electrode H are shown in Figure 52. Here, Electrode G is shown by a solid line and Electrode H by a dotted line, respectively. Figure 52(A) shows the charge and discharge cur ves of the first cycle, and Figure 52(B) shows the charge and discharge curves of the 10th cycle, respectively. This Here, the vertical axis represents voltage, and the horizontal axis represents capacitance normalized by the weight of sample E.

[0439] In Figure 52(B), the discharge capacities of electrode G and electrode H are approximately 322 mAh / g. The average was 259mAh / g. Conductor 201 (equivalent to RGO-1A) had a maximum capacity of 48mAh. It was / g. Therefore, the contribution of conductor 201 is a maximum of 48 × 0.54 = 30 [mAh / It can be estimated that the capacity of electrode G is 30 mAh / g compared to electrode H. It is estimated that it will be higher. However, in Figure 52(B), electrode G is compared to electrode H. This resulted in a larger capacity of 63mAh / g. Therefore, for example, with each charge-discharge cycle, The capacitance of conductor 201 may have increased. Alternatively, the capacitance of conductor 201 may have increased, as may the capacitance of samples E and AB. , or the reaction between PVDF and the NMP used during charging and discharging, or the reaction between PVDF and the NMP used during electrode G fabrication. It is possible that the reaction is contributing in some way.

[0440] Next, in order to investigate the reaction with the conductor 201 in layer 102, an undercoat was applied to the aluminum current collector. A layer 1102 was created by applying mixture F to a sheet 1103 that had been treated with a coating. GO-1 was placed on 1102 and heat-treated at 250°C. The heat-treated GO-1 was then... Let this be referred to as conductor 1201.

[0441] After that, the conductor 1201 was peeled off. The layers 1102 and conductor 1201 after peeling were A photograph is shown in Figure 59. The region where the conductor 1201 overlapped layer 1102 is called area 1. Let's call the area that did not overlap area 2.

[0442] Figure 60 shows the XPS measurement results for area1 and area2. Figure 60(A) shows sulfur Figure 60(B) shows the spectrum of S2P for , and Figure 60(B) shows the spectrum of Mn2p for manganese, respectively.

[0443] In the region overlapping with conductor 1201, peaks suggesting the presence of sulfur compounds were detected. The sulfur concentrations detected by XPS were 5.7 atomic% in area 1 and 2 in area 2. The atomic percentage was 0.

[0444] Furthermore, in the region overlapping with conductor 1201, there was a peak suggesting the presence of manganese. It was not detected. Therefore, in area 1, a layer containing sulfur was formed on layer 1102. This is a possibility. The manganese concentration detected by XPS was 0 atomic%, in area 1. Area 2 was 6.0 atomic%. The sulfur contained in GO-1 was in the same layer as layer 1102. It is possible that deposition occurred at the interface, and that a reaction took place between the conductor 1201 and layer 1102. This suggests the possibility. [Explanation of Symbols]

[0445] 100 Energy storage devices 101 Electrode 102 layers 103 Active material 107 Separator 111 Positive electrode 111a positive electrode 115 Negative electrode 115a negative electrode 121 Positive electrode current collector 122 Cathode active material layer 123 Separator 125 Negative electrode current collector 126 Negative electrode active material layer 130 Electrode assembly 131 Electrode assembly 151 Electrode 158 Electrolytes 201 Conductors 202 areas 202a area 211 Graphene compounds 222 Graphene Compound Sheet 280 Spray Drying Equipment 281 Chamber 282 nozzles 283 Tube 284 Dispersion 285 Heater 286 Collection containers 287 circuit boards 300 Battery 301 Positive electrode can 302 Negative electrode can 303 Gasket 304 Positive electrode 305 Positive electrode current collector 306 Positive electrode active material layer 307 Negative electrode 308 Negative electrode current collector 309 Negative electrode active material layer 310 Separator 321 Graphene compounds 331 areas 332 areas 333 areas 500 Battery 501 Positive electrode current collector 502 Positive electrode active material layer 503 Positive electrode 504 Negative electrode current collector 505 Negative electrode active material layer 506 negative electrode 507 Separator 508 Electrolyte 509 Exterior 510 Positive lead electrode 511 Negative lead electrode 514 Sealing part 600 Battery 601 Positive Cap 602 Battery Can 603 Positive terminal 604 Positive electrode 605 Separator 606 negative electrode 607 Negative terminal 608 Insulating board 609 Insulating board 611 PTC element 612 Safety valve mechanism 900 Circuit Boards 910 Labels 911 terminal 912 Circuit 913 Storage Battery 914 Antenna 915 Antenna 916 layers 917 layers 918 Antenna 919 terminal 920 Display device 921 Sensor 922 terminals 951 terminal 952 terminals 980 Energy Storage Device 983 Exterior 983a Exterior 983b Exterior body 990 Battery 991 Exterior 992 Exterior 993 Wound body 996 Separator 997 Lead Electrode 998 Lead Electrode 1102 layers 1201 Conductor 1700 curved surface 1701 Plane 1702 Curve 1703 Radius of curvature 1704 Center of curvature 1800 Center of curvature 1801 film 1802 radius of curvature 1803 film 1804 radius of curvature 7100 Portable Display Device 7101 enclosure 7102 Display section 7103 Operation Buttons 7104 Energy storage device 7200 Mobile Information Terminal 7201 enclosure 7202 Display section 7203 Band 7204 Buckle 7205 Operation Buttons 7206 Input / output terminal 7207 Icons 7300 display device 7304 Display section 7400 mobile phones 7401 enclosure 7402 Display section 7403 Operation Buttons 7404 External connection port 7405 Speaker 7406 Microphone 7407 Energy storage device 7408 Lead Electrode 7409 Current collector 8000 display device 8001 enclosure 8002 Display section 8003 Speaker section 8004 Energy Storage Device 8021 Charging device 8022 Cable 8024 Energy storage device 8100 Lighting device 8101 enclosure 8102 Light source 8103 Energy storage device 8104 Ceiling 8105 Side wall 8106 floor 8107 Window 8200 indoor unit 8201 enclosure 8202 Air outlet 8203 Energy Storage Device 8204 Outdoor unit 8300 Electric Refrigerator / Freezer 8301 enclosure 8302 Refrigerator door 8303 Freezer door 8304 Energy storage device 8400 automobiles 8401 Headlight 8406 Electric motor 8500 automobiles 9600 Tablet devices 9625 Switch 9626 Switch 9627 Power switch 9628 Operation switch 9629 Fastener 9630 cabinet 9630a enclosure 9630b enclosure 9631 Display section 9631a Display section 9631b Display section 9632a area 9632b area 9633 Solar Cell 9634 Charge / Discharge Control Circuit 9635 Energy Storage Unit 9636 DC-DC converter 9637 Converter 9638 Operation Keys 9639 button 9640 Moving parts

Claims

1. It has a graphene aggregate, a thickness of 800 nm to 20 μm, and an area of ​​25 mm². ２ 10m or more ２ The following is a current collector for a secondary battery: The current collector for the secondary battery is, It has a six-membered ring composed of carbon, A portion of the material has a carbon concentration greater than 80 atomic%, and an oxygen concentration of 2 atomic% or more and 20 atomic% or less, as measured by X-ray photoelectron spectroscopy (provided that the sum of the carbon and oxygen concentrations is 100 atomic%). Electrical conductivity of 0.1 S / cm or higher 10 ７ A current collector for a secondary battery having a portion with a current density of S / cm or less.

2. It has a graphene aggregate, a thickness of 800 nm to 20 μm, and an area of ​​25 mm². ２ 10m or more ２ The following is a current collector for a secondary battery: The current collector for the secondary battery is, It has a six-membered ring composed of carbon and a multi-membered ring of seven or more members composed of carbon, The multi-membered ring has a region in its vicinity through which lithium ions can pass, A portion of the material has a carbon concentration greater than 80 atomic%, and an oxygen concentration of 2 atomic% or more and 20 atomic% or less, as measured by X-ray photoelectron spectroscopy (provided that the sum of the carbon and oxygen concentrations is 100 atomic%). Electrical conductivity of 0.1 S / cm or higher 10 ７ A current collector for a secondary battery having a portion with a current density of S / cm or less.

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