Lithium-ion rechargeable battery

Abstract

To provide a power storage device whose decrease in capacity along with a charge-discharge cycle is small, a power storage device with a long life, or a power storage device with high reliability.SOLUTION: A power storage device includes a positive electrode, a negative electrode, and an electrolyte solution. The negative electrode includes a first element and carbon. The first element is any of silicon, tin, gallium, aluminum, germanium, lead, antimony, bismuth, silver, zinc, cadmium, and indium. The negative electrode includes an active material, and a first layer in contact with a surface of the active material. The first layer has a thickness of 10 nm or more and 1000 nm or less. The electrolyte solution includes a first cation and a second cation. The first cation is one or more selected from a lithium ion, a sodium ion, a calcium ion, and a magnesium ion. The second cation is an imidazolium cation or a tertiary sulfonium cation.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a product, method, or method of manufacture. Or, the present invention relates to a process, machine Relating to a manufacturer or composition of matter. In one aspect of the present invention, semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, and the The present invention relates to a method for driving or a method for manufacturing the same. In particular, one aspect of the present invention relates to an energy storage device Regarding the method of making it.

[0002] In this specification, the term "energy storage device" refers to all elements and devices that have an energy storage function. That is the case. [Background technology]

[0003] In recent years, secondary batteries such as lithium-ion secondary batteries, lithium-ion capacitors, air batteries, etc. The development of various energy storage devices is actively underway. In particular, high output and high energy density are being pursued. Lithium-ion rechargeable batteries are used in mobile phones, smartphones, and notebook personal computers. Electronic devices such as portable information terminals, portable music players, digital cameras, or medical devices. , hybrid electric vehicle (HEV), electric vehicle (EV), or plug-in hybrid vehicle (P With the development of the semiconductor industry, next-generation clean energy vehicles such as HEVs are rapidly increasing. Demand is expanding, and it is becoming indispensable to modern information society as a source of rechargeable energy. It is.

[0004] In rechargeable batteries that use carrier ion reactions, such as lithium-ion batteries, charging and discharging The volume of the active material may change during the process of electricity generation. For example, as described in Non-Patent Document 1 Furthermore, it is known that the interlayer distance of graphite increases from 0.336 nm to 0.370 nm. (See Non-Patent Document 1, pp. 333-334).

[0005] Furthermore, as described in Patent Document 1, for example, in alloy materials such as silicon, charging and discharging Repeating this process may change its shape and volume. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2013-214501 [Non-patent literature]

[0007] [Non-Patent Document 1] Masaki Yoshio et al., “Lithium-Ion Batteries Science and Technologies”, Springer, chapter 16, pp. 333-334. [Overview of the project] [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 provides an energy storage device that exhibits minimal capacity degradation associated with charge-discharge cycles. One of the objectives is to provide a long-life energy storage device. Alternatively, one aspect of the present invention provides a long-life energy storage device. One of the challenges is to provide a highly reliable energy storage device. This will be one of the challenges.

[0010] 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. Alternatively, one aspect of the present invention relates to an energy storage device that exhibits minimal degradation in characteristics when subjected to repeated external forces. One of the objectives is to provide a device.

[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 comprises a positive electrode, a negative electrode, and an electrolyte, wherein the negative electrode comprises a first element and carbon It has the following elements, and the first element is silicon, tin, gallium, aluminum, germanium, It is one of the following: lead, antimony, bismuth, silver, zinc, cadmium, or indium. The negative electrode has an active material and a first layer in contact with the surface of the active material, and the first layer has a thickness of 1 It has a portion between 0 nm and 1000 nm, and the electrolyte contains a first cation and a second cation. It has ions, and the first cation is lithium ion, sodium ion, calcium ion One or more ions are selected from ions or magnesium ions, and the second cation is imidazolium cationic acid. It is a battery that is either ON or a tertiary sulfonium cation.

[0013] Alternatively, one aspect of the present invention comprises a positive electrode, a negative electrode, and an electrolyte, wherein the negative electrode is a first element It has carbon and, the first element is silicon, tin, gallium, aluminum, germanium any of the following: nium, lead, antimony, bismuth, silver, zinc, cadmium, or indium The negative electrode consists of a first region, a second region in contact with the surface of the first region, and the second region It has a third region in contact with the surface of and the second and third regions have a layered shape. Furthermore, the thickness of the second region is between 10 nm and 500 nm, and the thickness of the third region is 10 nm The wavelength is between m and 1000 nm, and the atomic ratio of carbon to the first element in the first region is carbon Let the ratio of elements be x1:y1, and the atomic ratio of carbon to element 1 in the second region be Let carbon:first element = x²:y², and the atomic ratio of carbon to the first element in the third region. Let the ratio be carbon:first element = x3:y3, where x1 / y1 is less than or equal to 3, and x2 / y2 is 0.1 The above is less than 10, x3 / y3 is 5 or more, and the electrolyte is a first cation and a second It has a cation, and the first cation is a lithium ion, a sodium ion, and a calcium ion. One or more ions selected from mu ions or magnesium ions, and the second cation is imidazoliu It is a storage battery that contains a mucation or a tertiary sulfonium cation.

[0014] Furthermore, in the above configuration, the second cation may be an aromatic cation, an aliphatic onium cation, etc. Thione, etc. can be used. As aromatic cations, pyridinium cations, etc. Imidazolium cations can be used. As an aliphatic onium cation, four quaternary ammonium cations, tertiary sulfonium cations, and quaternary phosphonium cations The above can be used. In addition, in the above configuration, the second cation can be the chemical described later. It is preferable to use any of the cations shown in chemical formula (1) to chemical formula (17).

[0015] Furthermore, in the above configuration, the anions are monovalent amide anions and monovalent methide anions. Anions, fluorosulfonate anions, perfluoroalkyl sulfonate anions, te Trafluoroborate anions, perfluoroalkylborate anions, hexafluoro Use a phosphate anion or a perfluoroalkyl phosphate anion, etc. It is possible.

[0016] Alternatively, one aspect of the present invention is an electronic device having a storage battery as described above. Furthermore, it is preferable that the electronic device has a display device. Also, the electronic device has input / output terminals. Preferably, the input / output terminal has the function of performing wireless communication.

[0017] Alternatively, one aspect of the present invention is a battery control unit having a storage battery as described above. That is the case. [Effects of the Invention]

[0018] According to one aspect of the present invention, a novel electrode can be provided. This allows us to provide more novel energy storage devices.

[0019] Furthermore, according to one aspect of the present invention, an energy storage device is provided that exhibits minimal capacity reduction associated with charge-discharge cycles. It can be provided. Furthermore, according to one aspect of the present invention, a long-life energy storage device can be provided. This is possible. Furthermore, according to one aspect of the present invention, a highly reliable energy storage device can be provided. .

[0020] Furthermore, according to one aspect of the present invention, an electrode with a large capacity can be provided. In one aspect, a high-energy-density energy storage device can be provided. In one embodiment, a power storage device is provided that exhibits minimal degradation in performance when subjected to repeated external forces. It is possible.

[0021] 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]

[0022] [Figure 1] A diagram illustrating the components of an electrolyte solution. [Figure 2] A diagram illustrating a particle according to one embodiment of the present invention. [Figure 3] A diagram illustrating a portion of the electrode's cross-section. [Figure 4] A diagram explaining storage batteries. [Figure 5] A diagram illustrating a cross-section of a battery. [Figure 6] A diagram illustrating the method for manufacturing a rechargeable battery. [Figure 7] A diagram illustrating the method for manufacturing a rechargeable battery. [Figure 8] A diagram explaining storage batteries. [Figure 9] A diagram illustrating the method for manufacturing a rechargeable battery. [Figure 10] A diagram illustrating the method for manufacturing a rechargeable battery. [Figure 11] A diagram illustrating the method for manufacturing a rechargeable battery. [Figure 12] A diagram illustrating the method for manufacturing a rechargeable battery. [Figure 13] A diagram illustrating the radius of curvature of a surface. [Figure 14] A diagram illustrating the radius of curvature of film. [Figure 15]A diagram illustrating a coin-type rechargeable battery. [Figure 16] A diagram illustrating a cylindrical storage battery. [Figure 17] A diagram illustrating a portion of the cross-section of a battery. [Figure 18] A diagram illustrating a portion of the cross-section of a battery. [Figure 19] A diagram illustrating a portion of the cross-section of a battery. [Figure 20] A diagram showing an example of a storage battery. [Figure 21] A diagram showing an example of a storage battery. [Figure 22] A diagram illustrating an example of an energy storage system. [Figure 23] A diagram illustrating an example of an energy storage system. [Figure 24] A diagram illustrating an example of an energy storage system. [Figure 25] A diagram illustrating an example of an electronic device. [Figure 26] A diagram illustrating an example of an electronic device. [Figure 27] A diagram illustrating an example of an electronic device. [Figure 28] A diagram illustrating an example of an electronic device. [Figure 29] A block diagram illustrating one aspect of the present invention. [Figure 30] A conceptual diagram illustrating one aspect of the present invention. [Figure 31] A circuit diagram illustrating one aspect of the present invention. [Figure 32] A circuit diagram illustrating one aspect of the present invention. [Figure 33] A conceptual diagram illustrating one aspect of the present invention. [Figure 34] A block diagram illustrating one aspect of the present invention. [Figure 35] A flowchart illustrating one aspect of the present invention. [Figure 36] CV measurement results. [Figure 37] CV measurement results. [Figure 38] CV measurement results. [Figure 39] CV measurement results. [Figure 40] CV measurement results. [Figure 41] CV measurement results. [Figure 42] A diagram showing the charge and discharge characteristics. [Figure 43] A diagram showing the cycle characteristics. [Figure 44] XPS analysis results. [Figure 45] XPS analysis results. [Figure 46] XPS analysis results. [Figure 47] Cross-sectional TEM observation results. [Figure 48] Cross-sectional TEM observation results. [Figure 49] Cross-sectional observation image and EDX analysis results. [Figure 50] Cross-sectional observation image and EDX analysis results. [Figure 51] EDX analysis results. [Figure 52] Cross-sectional observation images and EELS analysis results. [Figure 53] Cross-sectional observation images and EELS analysis results. [Figure 54] A diagram illustrating a negative electrode according to one embodiment of the present invention. [Modes for carrying out the invention]

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] (Embodiment 1) This embodiment describes a storage battery according to one aspect of the present invention.

[0029] A storage battery according to one aspect of the present invention comprises a positive electrode, a negative electrode, and an electrolyte.

[0030] In one embodiment of the present invention, the electrolyte of the storage battery is preferably an ionic liquid. A storage battery according to one aspect of the present invention has a first cation in addition to the ions constituting the ionic liquid. It is preferable to do so. For example, alkali metal ions and alkalis may be used as the first cation. Alkali metal ions and alkaline earth metal ions can be used. When "ON," it functions as a carrier ion for the battery.

[0031] Examples of alkali metals include lithium, sodium, and potassium. Potassium earth metals include calcium, strontium, barium, beryllium, and ma Examples include magnesium.

[0032] When lithium is used as a carrier ion, for example, LiPF6, Li ClO4, LiAsF6, LiBF4, LiAlCl4, LiSCN, LiBr, LiI Li2SO4, Li2B 10 Cl 10 Li2B 12 Cl 12 , LiCF3SO3, L iC4F9SO3, LiC(CF3SO2)3, LiC(C2F5SO2)3, LiN( CF3SO2)2, LiN(C4F9SO2)(CF3SO2), LiN(C2F5SO 2) One type of lithium salt, or any combination and ratio of two or more of these. It can be dissolved by a certain percentage.

[0033] Here, the carrier ion concentration is higher than 0.1 mol / L and less than 3 mol / L. It is preferable that the concentration is 0.3 mol / L or higher and more preferably 2.5 mol / L or lower. It's nice.

[0034] The electrolyte may also contain a solvent other than an ionic liquid. For example, an aprotic organic solvent. It may have a non-protic organic solvent such as ethylene carbonate (EC). , propylene carbonate (PC), butylene carbonate, chloroethylene carbonate T, vinylene carbonate, γ-butyrolactone, γ-valerolactone, dimethyl carbonate Diethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EM) C) Methyl formate, methyl acetate, methyl butyrate, 1,3-dioxane, 1,4-dioxane , dimethoxyethane (DME), dimethyl sulfoxide, diethyl ether, methyl dig Lime, acetonitrile, benzonitrile, tetrahydrofuran, sulfolane, sultone One of these, or two or more of these, can be used in any combination and ratio. Cut.

[0035] During the charging and discharging of a rechargeable battery, a decomposition reaction of the electrolyte may occur. The solution is mainly generated by electrical reactions near the surface of the electrode.

[0036] Battery using alkali metal ions and alkaline earth metal ions as carrier ions In some cases, for example, the reaction potential of the negative electrode is low, making it easy for the electrolyte to decompose. Now consider the case where the electrolyte decomposes due to a reduction reaction near the surface of the negative electrode. If the solution is an irreversible reaction, the irreversible capacity may increase. Here, the irreversible capacity and This is the difference between the charging capacity and the discharging capacity. An increase in irreversible capacity reduces the capacity of the storage battery.

[0037] To suppress the decrease in battery capacity, irreversible reactions of the electrolyte near the electrode surface must be controlled. It is preferable to suppress this. For example, among the components of the electrolyte, the main carrier ions It promotes the reaction of certain alkali metal ions and alkaline earth metal ions, and also promotes the reaction of other components. It is preferable to suppress the reaction of elements, such as cations and anions of ionic liquids.

[0038] Figure 1(A) is a model showing the components of the electrolyte on the surface of the negative electrode active material 671 of the storage battery. This is a diagram. The electrolyte has a first cation 681 and an ionic liquid. It has cation 682 and anion 683. For example, the first cation 681 Lithium ion as cation 682, 1-ethyl-3-methylimi Dazolium (EMI) can be used.

[0039] Lithium has an extremely low oxidation-reduction potential, which is -3.045V relative to the standard electrode potential. It has the ability to increase the voltage of the energy storage device as the reaction potential of the negative electrode active material decreases. This is preferable. On the other hand, when the potential is low, the reducing force on the electrolyte also increases, for example, electrolysis Organic solvents used in the solution may be subject to reductive decomposition. Compared to the oxidation-reduction potential of lithium. When the reaction potential at the negative electrode of a lithium-ion battery is equivalent to or slightly higher than that of the other battery. This is preferable because it can increase the voltage of the energy storage device. On the other hand, the solvent of the electrolyte, here For example, the reaction potential of cations in ionic liquids is higher compared to the redox potential of lithium. There are many matches.

[0040] As the battery charges, the potential of the negative electrode active material 671 decreases. The potential of the negative electrode active material 671 is Potential at which the reaction of the first cation 681, cation 682, and anion 683 is significantly observed. Before reaching this point, charge accumulates at the negative electrode. As this charge accumulates, as shown in Figure 1(B) Thus, the first cation 681 forms an electric double layer on the surface of the negative electrode active material 671. Preferably, the surface of the electrical double layer formed by the first cation 681 may contain, for example, an anio 683 is arranged. In Figure 1(B), the surface of the negative electrode active material 671 of cation 682. Reaching that destination is suppressed.

[0041] If the reaction potential of cation 682 is higher than the reaction potential of the first cation 681, then negative As the electrode potential decreases to the reaction potential of cation 682, the reaction of cation 682 becomes apparent. This occurs. However, as shown in Figure 1(B), cation 682 does not reach the negative electrode surface. If this is suppressed, the reaction potential of the first cation 681 will not be reached until cation 6 It can suppress reaction 82.

[0042] Next, when the potential of the negative electrode drops to a potential at which the reaction of the first cation 681 occurs significantly... Consider this. The reduction reaction of the first cation 681 consumes the first cation 681. . With the reduction of the first cation 681, for example, the first cation 681 and the negative electrode active material 671 It may form a compound. Alternatively, the first cation 681 may be deionized by reduction. This can lead to the formation of a precipitate layer 681b on the surface of the negative electrode active material 671.

[0043] Here, as the first cation 681 is consumed, it forms on the surface of the negative electrode active material 671. The formed electric double layer disappears, and new cations reach the surface of the negative electrode active material 671. Therefore, when cation 682 reaches the surface of the negative electrode active material 671, the Reversible reactions, such as reductive decomposition, may occur, forming reactant 684. Reactant 68 4 may accumulate and form a coating 685 on the surface of the negative electrode active material 671.

[0044] Therefore, the first cation 681 reaches the surface of the negative electrode active material 671 faster than cation 682. It is preferable to reach the first ka in the electrolyte as shown in Figure 1(D). If the diffusion rate of thion 681 is faster than that of cation 682, then the reaction of cation 682 This suppresses the reaction of the primary carrier ion, cation 681, and promotes the reaction of the primary carrier ion, cation 681. Cut.

[0045] Now, let's consider the case where an aprotic organic solvent is used as the solvent for the electrolyte. Thione 681 is coordinated (solvated) by the solvent. Here, the main carrier ion is The first cation 681 moves to the vicinity of the negative electrode surface and forms an electrical double layer, Since the medium is neutral, it moves to the vicinity of the negative electrode surface in a solvated state, and the first cation 68 1 may inhibit the formation of an electrical double layer.

[0046] On the other hand, when an ionic liquid is used as the solvent for the electrolyte, the first cation 681 contains A It is thought that nion 683 coordinates. The first cation 681 moves to the vicinity of the negative electrode surface. Furthermore, when forming the electric double layer, anion 683 has a negative charge, so from the negative electrode surface It is subjected to an electric field in the direction of repulsion. Therefore, as the first cation 681 approaches the negative electrode surface... Therefore, the coordinating force of anion 683 weakens, and it is thought to detach. Thus, the solvent of the electrolyte... Compared to using an aprotic organic solvent, the electrical double layer of the first cation 681 It is thought to be easily formed.

[0047] [Diffusion rate of cations] In the electrolyte of a storage battery according to one aspect of the present invention, the diffusion rate of the first cation 681 is It is preferable that the diffusion rate is faster than that of thione-682. The diffusion rate of a cation depends on its molecular weight and electrical charge. It is determined by factors such as the uneven distribution of the load and its three-dimensional structure.

[0048] For example, if the molecular weight of cation 682 is large, the diffusion rate of cation 682 will be small. However, this leads to an increase in the viscosity of the electrolyte. As the viscosity of the electrolyte increases, the main carrier ions... The diffusion rate of a certain first cation 681 also decreases. As the temperature decreases, the output characteristics of the storage battery deteriorate.

[0049] For cation 682, aromatic cations, aliphatic onium cations, etc., can be used. Yes, it is possible. Aromatic cations include pyridinium cations and imidazolium cations. The following can be used. As an aliphatic onium cation, a quaternary ammonium cation, Tertiary sulfonium cations and quaternary phosphonium cations can be used.

[0050] For example, an ionic liquid containing an imidazolium cation is represented by the following general formula (G1). An ionic liquid can be used. In general formula (G1), R 1 is a carbon-numbered The above represents an alkyl group of 4 or less, R 2 ~R 4 Each of these is independently a hydrogen atom or a carbon atom. R5 represents an alkyl group with a number between 1 and 4, and R5 can be an alkyl group, or C, O, Si, N It represents a main chain composed of two or more atoms selected from S and P. Also, R 5 Place on the main chain Substituents may be introduced. Examples of substituents that can be introduced include alkyl groups and aldehyde groups. Examples include the coxy group.

[0051] [ka]

[0052] As the ionic liquid having a tertiary sulfonium cation, for example, an ionic liquid represented by the following general formula (G2) can be used. In the general formula (G2), R to R 25 to R 27 each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl [[ID=l0]]group. Alternatively, as R 25 to R 27 a main chain composed of two or more selected from the atoms of C, O, Si, N, S, and P may be used.

[0053]

Chemical formula

[0054] As the ionic liquid having a quaternary ammonium cation, for example, ionic liquids represented by the following general formulas (G4), ( G5) and (G6) can be used.

[0055]

Chemical formula

[0056] In general formula (G4), R 12 to R 17 each independently represents an alkyl group having 1 to 20 carbon atoms, a methoxy group, a methoxymethyl group, a methoxyethyl group, or any one of hydrogen atoms.

[0057]

Chemical formula

[0058] In general formula (G5), R 18 to R 24 each independently represents an alkyl group having 1 to 20 carbon atoms, Alkyl group, methoxy group, methoxymethyl group, methoxyethyl group, or hydrogen atom It represents one of them.

[0059] [ka]

[0060] In the general formula (G6), n and m are between 1 and 3. α is between 0 and 6, and n is 1. In case α is between 0 and 4, when n is 2, α is between 0 and 5, when n is 3, α is It is between 0 and 6. β is between 0 and 6, and when m is 1, β is between 0 and 4, and m When m is 2, β is between 0 and 5, and when m is 3, β is between 0 and 6. When β is 0, it means there is no substitution. Also, when both α and β are 0, substitution is not performed. X or Y shall be a linear or side-chain substituent with 1 to 4 carbon atoms. an alkyl group, a linear or side-chain alkoxy group having 1 to 4 carbon atoms, or carbon This represents a linear or side-chain alkoxyalkyl group with a number between 1 and 4.

[0061] For example, an ionic liquid having a pyridinium cation is represented by the following general formula (G3): An ionic liquid may also be used. In general formula (G3), R 6 is an alkyl group, or R represents a main chain composed of two or more atoms selected from C, O, Si, N, S, and P. 7 ~R 11 Each of these independently contains a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. To represent. Also, R 6 A substituent may be introduced into the main chain. Possible substituents to be introduced are: Examples include alkyl groups and alkoxy groups.

[0062] [ka]

[0063] A- as shown in general formulas (G1) to (G6) can be used in anion 683. You should refer to the anion.

[0064] When using a pyridinium cation with a molecular weight of 150 or less as cation 682, The cation 682 diffuses rapidly into the electrolyte, reaching the negative electrode surface and causing a decomposition reaction. In some cases, this is likely to occur. On the other hand, tertiary sulfonyl cation 682 has a molecular weight of 110 or more. Imidazolium cations, imidazolium cations with a molecular weight of 100 or more, and imidazolium cations with a molecular weight of 130 or more By using the above quaternary ammonium cation, compared to the first cation 681, It is preferable that the diffusion rate of thion-682 can be reduced. Here, the molecular weight is 220 or less. The following tertiary sulfonium cations, and a molecular weight of 250 or less, more preferably 175 or less. By using imidazolium cations, the increase in the viscosity of the electrolyte is kept to a minimum. This may be possible, and is preferable.

[0065] An ionic liquid according to one aspect of the present invention is an ionic liquid represented by general formulas (G1) to (G6). It is preferable to use ionic liquids represented by general formulas (G1) and (G2). It is more preferable to use an ionic liquid represented by the general formula (G1). stomach.

[0066] Anion 683 includes monovalent amide anions, monovalent methide anions, and fluoro Sulfonate anions, perfluoroalkyl sulfonate anions, tetrafluorovole Toanions, perfluoroalkylborate anions, hexafluorophosphate anions On (PF6 - ), or the use of perfluoroalkyl phosphate anions, etc. can.

[0067] Examples of anion 683 include monovalent amide anions, monovalent methide anions, and Luorosulfonate anion (SO3F - ), fluoroalkyl sulfonate anions, etc. It is preferable to use it.

[0068] As for monovalent amide anions, (C n F 2n+1 SO2)2N - (n=0 or more and 3 or more (Below) As a monovalent cyclic amide anion, (CF2SO2)2N - These include: 1 As for methyl anions of value, (C n F 2n+1 SO2)3C - (n=0 or more and 3 or less) As a monovalent cyclic methide anion, (CF2SO2)2C - (CF3SO2) There are others. As for fluoroalkyl sulfonate anions, (C m F 2m+1 SO3) - Examples include (m=0 or greater and 4 or less). Examples of fluoroalkylborate anions include {BF n (C m H k F 2m+1-k ) 4-n} - (n=0 to 3, m=1 to 4, k= Examples include {PF (0 to 2m) and others. Fluoroalkyl phosphate anions include {PF n (C m H k F 2m+1-k )6-n} - (n=0 to 5, m=1 to 4, k= These include (0 to 2m). These anions are the first cation 681, and cation The interaction with 682 may be small, which is preferable. The first cation 681 and anion 68 If the interaction with 3 is small, the diffusion rate of the first cation 681 can be increased. In some cases, this may occur. Also, if the interaction between cation 682 and anion 683 is small, In some cases, it is possible to lower the melting point of the ionic liquid contained in the electrolyte.

[0069] For example, a monovalent amide anion is the bis(fluorosulfonyl)amide anion. The bis(trifluoromethanesulfonyl)amide anion can also be used.

[0070] Also, as anion 683, there is the tetrafluoroborate anion (BF4 - ), Fluo Even when using a fluoroalkylborate anion or a fluoroalkylphosphate anion good.

[0071] The compound used in the energy storage device according to one aspect of the present invention is a compound represented by the general formula (G7). It has an on state and an anion corresponding to a cation.

[0072] [ka]

[0073] In the formula, R 1 R represents an alkyl group with 1 to 4 carbon atoms. 2 ~R 4 These are, Independently, each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Also, in the formula, A 1 No To A4 Each of these independently represents either a methylene group or an oxygen atom, and A 1 Or A 4 at least Another one is the oxygen atom.

[0074] A substituent introduced to the nitrogen of the imidazolium cation (A in general formula (G7)) 1 Or A 4 Having substituents (including ) sterically increases the bulk of the cation species in the ionic liquid, thereby increasing the electrical charge Side reactions inside the pond (cation insertion and decomposition into graphite during charging, and the resulting gas generation) It can suppress (raw, etc.). However, A 1 Or A 4 As the number of carbon atoms increases, io The viscosity of the liquid also tends to increase, therefore, depending on the desired charge / discharge efficiency and desired viscosity It is preferable to control it as appropriate.

[0075] Furthermore, the anion in the above ionic liquid is composed of an imidazolium cation and an imidazolium cation. It is a monovalent anion. Examples of such anions include monovalent amide anions. Monovalent methide anions, fluorosulfonate anions (SO3F - ), fluoroalkyl Sulfonic acid anion, tetrafluoroborate anion (BF4 - ), fluoroalkyl Luborate anion, hexafluorophosphate anion (PF6) - ) or fluoro Examples include alkyl phosphate anions. And, monovalent amide anions... is, (C n F 2n+1 SO2)2N - (n=0 to 3), monovalent cyclic amide-based ani As for ON, (CF2SO2)2N - These include: Monovalent methide anions include: (C n F 2n+1 SO2)3C - (n=0 to 3), monovalent cyclic methide anions For example, (CF2SO2)2C - Examples include (CF3SO2). As a folic acid anion, (C m F 2m+1 SO3) - Examples include (m = 0 or greater, 4 or less). As for fluoroalkylborate anions, {BF n (C m H k F 2m+1-k )4 -n} - Examples include (n=0 to 3, m=1 to 4, k=0 to 2m). Examples of luoroalkyl phosphate anions include {PF n (C m H k F 2m+1-k )6 -n} - Examples include (n=0 to 5, m=1 to 4, k=0 to 2m). Oh, the anions in question are not limited to these.

[0076] Furthermore, the anion in the above ionic liquid is a monovalent amide anion, bis(full It is preferable that it be an orosulfonyl)amide anion. Ionic liquids using a combination of mid-anions and cations have high conductivity and relatively low It has a high viscosity. An energy storage device using this ionic liquid and graphite as the negative electrode is capable of charging and discharging. be.

[0077] Furthermore, the compound used in the energy storage device according to one aspect of the present invention is represented by the general formula (G8). It has a cation and an anion corresponding to the cation.

[0078] [Chemical]

[0079] In the formula, R 1 represents an alkyl group having 1 to 4 carbon atoms, and R 2 to R 4 each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0080] Also, the anion in the ionic liquid is a monovalent anion that constitutes the imidazolium cation and the ionic liquid. Examples of the anion include a monovalent amide-based anion, a monovalent methide-based anion, a fluorosulfonic acid anion (SO3F - ), a fluoroalkylsulfonic acid anion, a tetrafluoroborate anion (BF4 - ), a fluoroalkylborate anion, a hexafluorophosphate anion (PF6 - ), or a fluoroalkylphosphate anion, etc. And examples of the monovalent amide-based anion include n (C 2n+1 F - SO2)2N - (n = 0 to 3), and examples of the monovalent cyclic amide-based anion include (CF2SO2)2N n F 2n+1 SO2)2N - (n = 0 to 3), and examples of the monovalent cyclic amide-based anion include (CF2SO2)2N - and the like. Examples of the monovalent methide-based anion include (C n F 2n+1 SO2)3C - (n = 0 to 3), and examples of the monovalent cyclic methide-based anion include (CF2SO2)2C - (CF3SO2) and the like. Examples of the fluoroalkylsulfonic acid anion include (C m F 2m+1 SO3) -Examples include (m = 0 or greater, 4 or less). As for fluoroalkylborate anions, {BF n (C m H k F 2m+1-k )4 -n} - Examples include (n=0 to 3, m=1 to 4, k=0 to 2m). Examples of luoroalkyl phosphate anions include {PF n (C m H k F 2m+1-k )6 -n} - Examples include (n=0 to 5, m=1 to 4, k=0 to 2m). Oh, the anions in question are not limited to these.

[0081] Furthermore, the anions in the above ionic liquid are preferably monovalent amide anions. It's nice.

[0082] Furthermore, the compound used in the energy storage device according to one aspect of the present invention is represented by the general formula (G9). It has a cation and an anion corresponding to the cation.

[0083] [ka]

[0084] In the formula, R 1 R represents an alkyl group with 1 to 4 carbon atoms. 2 ~R 4 These are, Independently, each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0085] Furthermore, the anion in the above ionic liquid is composed of an imidazolium cation and an imidazolium cation. It is a monovalent anion. Examples of such anions include monovalent amide anions. Monovalent methide anions, fluorosulfonic acid anions (SO3F - ), fluoroalkyl sulfonic acid anions, tetrafluoroborate anions (BF4 - ), fluoroalkyl borate anions, hexafluorophosphate anions (PF6 - ) or fluoro alkyl phosphate anions and the like can be mentioned. And, as the monovalent amide anions there are, (C n F 2n+1 SO2)2N - (n = 0 or more and 3 or less), as the monovalent cyclic amide anions there are, (CF2SO2)2N - and the like. As the monovalent methide anions there are, (C n F 2n+1 SO2)3C - (n = 0 or more and 3 or less), as the monovalent cyclic methide anions there are, (CF2SO2)2C - (CF3SO2) and the like. As the fluoroalkylsulf onic acid anions there are, (C m F[[ID=​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​Oh, the anion is not limited to these.

[0086] In addition, the anion in the ionic liquid is preferably a monovalent amide-based anion. Preferably.

[0087] In addition, the alkyl group of the ionic liquid represented by the general formula (G7) to the general formula (G9) may be either linear or branched. For example, an ethyl group or a tert-butyl group. It is. Also, the ionic liquid represented by the general formula (G7) has an oxygen-oxygen bond to A 1 to A 4 (peroxide) is preferably not present. The single bond between oxygen atoms is very fragile <​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

[0094] [Chemical formula]

[0095] [Chemical formula]

[0096] Further, as specific examples of the cation of the above general formula (G2), for example, structural formulas (201) to structural formula (215) can be mentioned.

[0097] [Chemical formula]

[0098] [Negative electrode active material] When using a negative electrode active material as the active material, for example, an alloy-based material, a carbon-based material, etc. can be used. It is possible.

[0099] As the negative electrode active material, an element capable of performing a charge-discharge reaction by an alloying / dealloying reaction with lithium can be used. For example, silicon, tin, gallium, aluminum, germanium, lead, antimony, bismuth, silver, zinc, cadmium, indium, etc. Among them, a material containing at least one can be used. Such elements have a larger capacity compared to carbon, and especially silicon has a high theoretical capacity of 4200 mAh / g. Therefore, it is preferable to use silicon as the negative electrode active material. Also, a compound having these elements may be used. For example, SiO, Mg2Si, Mg2Ge, SnO, SnO2, Mg2Sn, SnS2, V2Sn3, FeSn2, CoSn2, Ni3Sn2, Cu6Sn5, Ag3Sn, Ag 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.

[0100] As described in Patent Document 1, for example, alloy materials such as silicon are involved in the alloying reaction of lithium. It is known that the volume expands further. Also, the expanded volume is due to dealloying with lithium. It contracts due to the reaction. The negative electrode active material expands and contracts as the battery charges and discharges. .

[0101] When the negative electrode active material is in an expanded state, a coating 685 is formed on the surface of the negative electrode active material. Afterward, the negative electrode active material shrinks with the coating 685 formed on its surface. During shrinkage, for example, the negative Stress is generated from the coating 685 on the electrode active material, causing cracks and other damage to form in the negative electrode active material. It is thought that the number will decrease. Also, during shrinkage, the coating 685 will get caught in the cracks, and Possible causes include cracks forming in the negative electrode active material, or the active material becoming pulverized. The surface has a mixed region of finely powdered negative electrode active material and a coating that is trapped between the negative electrode active materials. A pulverized negative electrode active material may lose its electrical conductivity. Losing this can prevent the charging and discharging reaction from occurring, potentially leading to a decrease in the battery's capacity. Therefore, it is preferable to suppress cracking and pulverization of the negative electrode active material.

[0102] In this specification, SiO refers to silicon monoxide, for example. Alternatively, SiO refers to Si It can also be expressed as Ox. Here, it is preferable that x has one neighboring value. For example, x is A value of 0.2 to 1.5 is preferred, and 0.3 to 1.2 is preferred.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] Here, when lithium ions are inserted into graphite, for example, the interlayer distance of the graphite becomes 0. It is known that the wavelength increases from 336 nm to 0.370 nm (Non-Patent Literature 1, p. 33). (See 3-334). In other words, the interlayer distance increases by approximately 11%.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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 CoS0.89 , 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.

[0111] [Pre-dope] Furthermore, irreversible reactions occur when a film is formed during the initial charge and discharge. For example, positive If the irreversible reaction at either the electrode or the negative electrode is greater than the charge-discharge balance, the balance between charge and discharge will be disrupted. This can lead to a decrease in the battery's capacity. After charging and discharging using the counter electrode, the electrodes are rearranged. In some cases, the decrease in capacity can be suppressed by performing this action. For example, by associating the positive electrode with the negative electrode. After charging or discharging, remove the positive electrode used for charging or discharging. By removing the old positive electrode and combining it with a new one to create a new battery, the reduction in battery capacity can be suppressed. It can sometimes be controlled. This method is sometimes called pre-doping or pre-aging.

[0112] By suppressing the formation of the coating 685 on the surface of the negative electrode active material, cracks in the negative electrode active material are prevented. , and in some cases, pulverization can be suppressed.

[0113] In one embodiment of the present invention, the negative electrode preferably comprises a first element and carbon. Here, The first element is silicon, tin, gallium, aluminum, germanium, lead, antimony It is preferable that it be one of the following: bismuth, silver, zinc, cadmium, or indium. stomach.

[0114] [The layer present in the negative electrode] A negative electrode according to one aspect of the present invention comprises a negative electrode active material and a first layer on the surface of the negative electrode active material. Here, the first layer is sometimes referred to as a coating. The thickness of the first layer is between 10 nm and 1000 nm. The lower range is preferable, 50 nm to 200 nm is more preferable, and 50 nm to 100 nm is preferable. The bottom one is even better.

[0115] Alternatively, the negative electrode in one aspect of the present invention comprises a first region and a second region in contact with the surface of the first region. It has a region and a third region in contact with the surface of the second region. It has a layered shape. The thickness of the second region is preferably 10 nm to 500 nm. More preferably between 50nm and 200nm, and even more preferably between 50nm and 100nm. The thickness of the third region is preferably 10 nm to 1000 nm, and 50 nm to 20 0 nm or less is more preferable, and 50 nm to 100 nm is even more preferable. First region Let x1:y1 be the atomic ratio of carbon to the first element in the second region. Let the atomic ratio of element 1 be x2:y2, and the atoms of carbon and element 1 in the third region. Let the ratio be x3:y3. x1 / y1 is preferably 3 or less, and more preferably 1.5 or less. x2 / y2 is preferably 0.1 or more and less than 10, and more preferably 0.3 or more and 5 or less. x3 / y3 is preferably 5 or greater, more preferably 10 or greater, and even more preferably 20 or greater.

[0116] The intensity ratio of carbon to the first element in the first region obtained by EDX analysis is x1:y Let the intensity ratio of carbon to the first element in the second region be 1, and let the intensity ratio of carbon to the first element in the third region be x2:y2. Let x3:y3 be the intensity ratio of carbon to the first element present in the material. x1 / y1 should ideally be 0.3 or less. It is preferable that x2 / y2 is between 0.1 and 5, and more preferably between 0.3 and 3. x3 / y3 is preferably 2 or greater, more preferably 5 or greater, and even more preferably 10 or greater.

[0117] The intensity ratio of carbon to the first element in the first region obtained by EELS analysis is x1: Let y1 be the intensity ratio of carbon to the first element in the second region, and let x2:y2 be the intensity ratio of carbon to the first element in the third region Let x3:y3 be the intensity ratio of carbon to the first element in the region. x1 / y1 is 0.3 or less. Preferably, x2 / y2 is between 0.1 and 5, and more preferably between 0.3 and 3. x3 / y3 is preferably 2 or greater, more preferably 5 or greater, and even more preferably 10 or greater.

[0118] Figure 54(A) shows the negative electrode in the first region 551, the second region 552, and the third region 553. An example having the above is shown. Also, as shown in Figure 54(B), the second region 552 is the first region It may be a mixed region of the material that makes up region 551 and the material that makes up the third region 553. Here, for example, the first region 551 is the negative electrode active material, and the third region 553 is the electrolyte. It is a coating formed by the accumulation of dissolved materials. The negative electrode active material has a first element, for example, silicon. If the decomposition products of the electrolyte contain carbon, then the first region 551 is carbon compared to silicon. The third region 553 has less of the carbon, and the third region 553 has more carbon compared to silicon. Compared to x1 / y1, x3 / y3 has a larger value.

[0119] Furthermore, the negative electrode in one embodiment of the present invention exhibits a 168 eV emission in the S2p spectrum of XPS analysis. The spectral intensity in the vicinity is, for example, more than twice the spectral intensity in the vicinity of 163 eV, or It is more than three times, or more than four times.

[0120] The current collectors for the positive and negative electrodes can be stainless steel, gold, platinum, aluminum, or titanium. Highly conductive materials such as metals and their alloys can be used. When the body is 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 When used in this context, it is preferable that it does not form alloys with carrier ions such as lithium. Elements that improve heat resistance, such as silicon, titanium, neodymium, scandium, and molybdenum. Aluminum alloys to which silicon is added can be used. In addition, silicon reacts with silicon to form silisa It may be formed from a metallic element that forms a silicide. Gold reacts with silicon to form a silicide. The group elements include zirconium, titanium, hafnium, vanadium, niobium, tantalum, Examples include chromium, molybdenum, tungsten, cobalt, and nickel. Current collectors come in foil or plate form. Appropriate shapes such as sheet, mesh, perforated metal, and expanded metal are used. This is possible. It is preferable to use a current collector with a thickness of 5 μm to 30 μm.

[0121] 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.

[0122] 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 When MxO2 (M=Co, Al, etc.) is mixed, This is preferable because it can improve the characteristics of secondary batteries using this method.

[0123] 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 using a microscope or TEM (transmission electron microscope), or using laser diffraction / scattering methods. It can be measured using a particle size distribution analyzer, etc. Furthermore, the specific surface area can be measured by the gas adsorption method. It can be determined.

[0124] 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 This involves using a lithium manganese composite oxide having regions with different crystal orientations or oxygen content. This is preferable. In order to obtain such a lithium manganese composite oxide, for example, 1.6 ≤ It is preferable to set a ≤ 1.848, 0.19 ≤ c / b ≤ 0.935, and 2.5 ≤ d ≤ 3. Furthermore, Li 1.68 Mn 0.8062 Ni 0.318 ​The chemical formula for O3 is It is particularly preferable to use thium manganese composite oxide. In this specification, Li 1. 68 Mn 0.8062 Ni 0.318 Lithium manganese composite represented by the chemical formula O3 Oxides are defined as a mixture where the ratio (molar ratio) of the raw materials is Li2CO3:MnCO3:NiO=0 Lithium manganese composite oxide formed by 0.84:0.8062:0.318 It refers to a substance. Therefore, the lithium manganese composite oxide has the compositional formula Li 1.68 Mn 0.80 62 Ni 0.318 It is represented as O3, but the composition may deviate from this.

[0125] The composition of the entire lithium manganese composite oxide particle, including metal, silicon, phosphorus, etc., is as follows: For example, it can be measured using ICP-MS (Inductively Coupled Plasma Mass Spectrometer). The oxygen composition of the entire particle of lithium manganese composite oxide is, for example, EDX (energy dispersion). It is possible to measure using (type X-ray spectroscopy). Furthermore, it can be used in combination with ICP-MS analysis. This can be determined by using valence evaluation from molten gas analysis and XAFS (X-ray absorption fine structure) analysis. This can be done. Furthermore, lithium manganese composite oxide is defined as 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:

[0126] 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 2.

[0127] As shown in Figure 2(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, the outside This indicates that it is closer to the surface of the particle. Also, region 333 is lithium manganese complex acid It is preferable that the particles containing the phosphate have a region that coincides with the surface.

[0128] Furthermore, as shown in Figure 2(B), region 331 has an area that is not covered by region 332. This is also fine. Furthermore, region 332 may have regions that are not covered by region 333. Also, for example Region 331 may have a region adjacent to region 333. Also, region 331 may have a region adjacent to region 333. It may have regions that are not covered by either region 2 or region 333.

[0129] Region 332 preferably has a different composition from region 331.

[0130] 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 The composition of each of the 32 can be measured, for example, by EDX using TEM. Measurements using this method may make it difficult to measure the lithium composition. Therefore, in the following, The differences in composition between region 331 and region 332 are described with respect to elements other than lithium. Here, d 1 / (b1+c1) is preferably 2.2 or greater, more preferably 2.3 or greater, and 2 It is even more preferable that it be between 0.35 and 3. Also, d² / (b²+c²) is 2.2. It is preferable that it is full, more preferably less than 2.1, and 1.1 or more and 1.9 or less. It is even more preferable that this is the case. Also in this case, the lithium including region 331 and region 332 The overall composition of the manganese composite oxide particles satisfies the aforementioned condition 0.26 ≤ (b+c) / d < 0.5. It is preferable to add it.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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. Alternatively, it refers to regions 332 and 331. 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.

[0135] 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. .

[0136] 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.

[0137] 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.

[0138] The film thickness in region 333 is preferably 0.4 nm or more and 40 nm or less.

[0139] 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.

[0140] Furthermore, the positive and negative electrodes may have conductive additives. Examples of conductive additives include carbon materials. Metal materials or conductive ceramic materials can be used. In addition, conductive additives can be used. Fibrous materials may be used. The content of the conductive additive relative to the total amount of the active material layer shall be 1 wt% or less. Preferably, the content is 10 wt% or less, and more preferably 1 wt% to 5 wt%.

[0141] 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.

[0142] 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.

[0143] Furthermore, graphene compounds may be used as conductive additives.

[0144] 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, graphene or multigraphene or reduced graphene It is particularly preferable to use an oxide (hereinafter referred to as RGO). Here, RGO is, for example, an acid. This refers to compounds obtained by reducing graphene oxide (GO). .

[0145] When using active materials with small particle sizes, for example, active materials with a particle size of 1 μm or less, the specific surface area of ​​the active material The size is large, and more conductive paths are needed to connect the active materials. In such cases, fewer Using a graphene compound that can efficiently form conductive paths even in small quantities is particularly advantageous. It is preferable.

[0146] The following is an example of the case where a graphene compound is used as a conductive additive in the active material layer. An example of surface configuration will be explained.

[0147] Figure 3(A) shows a longitudinal cross-sectional view of the active material layer. The active material layer consists of granular active material 103 and conductive The material contains graphene compound 321 as an auxiliary agent and a binder (not shown). Here, For example, graphene or multigraphene can be used as the phen compound 321. Therefore, it is preferable that the graphene compound 321 has a sheet-like shape. The graphene compound 321 is composed of multiple multigraphenes, or / or multiple graphenes. They may overlap in sections to form a sheet-like structure.

[0148] In the longitudinal section of the active material layer, as shown in Figure 3(A), the interior of the active material layer is roughly The graphene compound 321 is uniformly dispersed in a sheet-like form. In Figure 3(A), graphene Compound 321 is schematically represented by a thick line, but in reality, the thickness of the single or multilayer carbon molecules is... It is a thin film having multiple graphene compounds 321 that surround multiple granular active materials 103. Formed to cover or adhere to the surface of multiple granular active materials 103. Therefore, they are in surface contact with each other.

[0149] 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.

[0150] Here, graphene oxide is used as graphene compound 321 and mixed with the active material to produce the active material It is preferable to reduce the material after forming the layer that will become the matrix. By using graphene oxide, which has extremely high dispersibility in a solvent, graphene compounds 321 can be dispersed approximately uniformly within the active material layer. To remove the solvent from the dispersion medium containing graphene oxide and reduce the graphene oxide, The graphene compound 321 remaining in the active material layer 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.

[0151] 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 allows us to increase the ratio of active material 103 in the active material layer. This allows for an increase in the discharge capacity of the energy storage device.

[0152] Furthermore, the positive and negative electrodes may contain a binder. For example, styrene-buta Diene rubber (SBR), styrene-isoprene-styrene rubber, acrylonitrile-porcine rubber Rubber materials such as diene rubber, butadiene rubber, and ethylene-propylene-diene copolymers It is preferable to use it. Furthermore, fluororubber can be used as a binder.

[0153] 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.

[0154] 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, polyisobutylene, poly Ethylene terephthalate, nylon, polyvinylidene fluoride (PVdF), polyacrylo Nitrile (PAN), ethylene propylene diene polymer, polyvinyl acetate, nitrocellulose It is preferable to use ingredients such as loin.

[0155] Multiple binding agents may be used in combination from the above options.

[0156] 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.

[0157] 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.

[0158] 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 polymers will interact with each other and exist to broadly cover the surface of the active material.

[0159] 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.

[0160] [Method for fabricating electrodes] As an example of a method for manufacturing the negative electrode and positive electrode, a slurry is prepared and the slurry is applied. Electrodes can be fabricated by this method. An example of a method for preparing the slurry used for electrode fabrication is described below. Bell.

[0161] Here, the solvent used to prepare the slurry is preferably a polar solvent. For example, water methanol, ethanol, acetone, tetrahydrofuran (THF), dimethylform Amides (DMF), N-methylpyrrolidone (NMP), and dimethyl sulfoxide (DMS) One or more of the following solutions (O) can be used.

[0162] First, the active material, conductive additive, and binder are mixed to prepare mixture A (Step S1). 10). Next, the solvent is added to mixture A, and kneading (kneading at high viscosity) is performed, and the mixture Prepare B (step S120). Here, the mixture B is, for example, in the form of a paste. Preferably. Here, if a second binder is added in the later step S141, In the case of TEP S110, it may not be necessary to add the first binder.

[0163] Next, the solvent is added to mixture B and kneaded to produce mixture C (Step S130) ).

[0164] Next, if a second binder is used, the second binder is added to prepare mixture D. Step S141). At this time, a solvent may be added. Also, if a second binder is not used. To prepare mixture E, add a solvent as needed (step S142).

[0165] Next, for example, mixture D or mixture E prepared under reduced pressure is kneaded to prepare mixture F. (Step S150). At this time, a solvent may be added. Here, steps S110 to In the mixing and kneading process of step S150, for example, a kneader can be used. .

[0166] Next, measure the viscosity of mixture F (step S160). Then, if necessary, add the solvent. The mixture is added and the viscosity is adjusted. Through the above steps, a slurry for coating the active material layer is obtained. ru.

[0167] Here, for example, in steps S130 to S160, mixture C to mixture The higher the viscosity of F, the better the dispersibility of the active material, binder, and conductive additive within the mixture. In some cases, one component may be superior (they mix well with each other). Therefore, for example, the viscosity of mixture F may be higher. It is preferable that the viscosity of the mixture F is too high, for example, the coating speed of the electrode This can sometimes be lower, which can be undesirable from a productivity standpoint.

[0168] Next, we will explain a method for creating an active material layer on a current collector using the prepared slurry. ru.

[0169] First, apply the slurry to the current collector. Before applying the slurry, apply the slurry to the current collector. Surface treatment may be performed. Examples of surface treatments include corona discharge treatment, plasma treatment, Examples include undercoating. Here, undercoating refers to applying slurry to the current collector. Before coating, the purpose is to reduce the interfacial resistance between the active material layer and the current collector, and the interaction between the active material layer and the current collector. This refers to a film formed on a current collector to improve adhesion. Note that the term "undercoat" does not necessarily mean "undercoat." It does not need to be in the form of a membrane; it may be formed in the form of islands. Also, the undercoat is the active material and It is acceptable to express capacity in this way. For the undercoat, for example, a carbon material can be used. This can be done. Examples of carbon materials include graphite, acetylene black, and Ketjenblack. Carbon black, carbon nanotubes, etc. (registered trademark) can be used.

[0170] Slurry application can be done using slot die methods, gravure methods, blade methods, and combinations thereof. A combination of methods can be used. Furthermore, a continuous coating machine may be used for application.

[0171] Next, by volatilizing the solvent in the slurry, an active material layer can be formed.

[0172] The solvent volatilization step of the slurry is performed at a temperature of 50°C to 200°C, preferably 60°C to 150°C. It is best to perform the procedure within a temperature range of °C or below.

[0173] For example, under conditions of 30°C to 70°C for 10 minutes or more, using a hot plate in an atmospheric environment After heat treatment, for example, a period of 1 to 10 hours at room temperature or above 100°C. The solution is to perform heat treatment under reduced pressure.

[0174] Alternatively, heat treatment may be performed using a drying oven or the like. When using a drying oven, for example Heat treatment should be performed at a temperature between 30°C and 120°C for between 30 seconds and 20 minutes.

[0175] Alternatively, the temperature may be increased in stages. For example, a heat treatment at 60°C or below for 10 minutes or less. After this, further heating at a temperature of 65°C or higher for at least one minute may be performed.

[0176] The thickness of the active material layer formed in this way is preferably, for example, 5 μm to 300 μm. More preferably, the thickness should be between 10 μm and 150 μm. Also, the active material of the active material layer The load amount is preferably, for example, 2 mg / cm³. 2 More than 50mg / cm 2 The following is acceptable.

[0177] The active material layer may be formed on both sides of the current collector, or on only one side. Alternatively, it may have regions where active material layers are formed on both sides in part.

[0178] After the solvent is evaporated from the active material layer, compression is performed using methods such as roll pressing or flat plate pressing. Pressing may be performed. Heat may be applied when pressing.

[0179] Furthermore, pre-doping may be performed on the active material layer. The method for pre-doping the active material layer is particularly important. This is not limited to, but can be done electrochemically, for example, before battery assembly. Using lithium metal as the counter electrode, lithium is added to the active material layer in the electrolyte solution described later. It can be redodoped. Alternatively, a positive electrode can be prepared for pre-doping, with the counter electrode being the negative electrode. Pre-doping may be performed, and then the positive electrode used for pre-doping may be removed. By doing so, it is possible to suppress the decrease in charge / discharge efficiency, especially during the initial charge and discharge, and increase the capacity of the storage battery. Cut.

[0180] This embodiment can be implemented in appropriate combination with other embodiments.

[0181] (Embodiment 2) This embodiment describes an energy storage device according to one aspect of the present invention.

[0182] 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.

[0183] <Thin-type rechargeable battery> Figure 4 shows a thin battery as an example of an energy storage device. The thin battery is flexible. If the configuration is such that it can be mounted on an electronic device having at least a part of a flexible component, Furthermore, the battery can be bent to match the deformation of the electronic device.

[0184] Figure 4 shows an external view of the thin battery, battery 500. Also, see Figures 5(A) and 5 (B) shows the A1-A2 and B1-B2 cross-sections, indicated by the dashed lines in Figure 4. Battery 5 00 is 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 504 and a negative electrode active material layer 505, a separator 507, and an electrolyte 5 It has 08 and an outer casing 509. A positive electrode 503 and a negative electrode 50 are provided inside the outer casing 509. A separator 507 is installed between 6 and 6. Also, the inside of the outer casing 509 contains electrolyte 508. It is filled with it.

[0185] The electrolyte used in the energy storage device contains particulate matter and elements other than the constituent elements of the electrolyte (hereinafter simply referred to as " It is preferable to use a highly purified electrolyte with a low content of impurities (also called "foulings"). Specifically, the weight ratio of impurities to the electrolyte is 1% or less, preferably 0.1% or less. Preferably, the amount is 0.01% or less.

[0186] 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 percentages should be less than or equal to 5.

[0187] Alternatively, a polymer gel electrolyte, obtained by swelling a polymer with an electrolyte solution, may be used.

[0188] 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.

[0189] 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.

[0190] For example, the separator 507 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.

[0191] 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 6(A), the positive electrode 503 is sandwiched between them. The sea urchin separator 507 is folded in half, and the sealing portion 51 is formed outside the area that overlaps with the positive electrode 503. By sealing with 4, the positive electrode 503 can be securely supported within the separator 507. Then, as shown in Figure 6(B), the positive electrode 503 and negative electrode 5 are enclosed in the separator 507. By alternately stacking 06 and these and arranging them inside the outer casing 509, a storage battery 500 is formed. It would be good to do so.

[0192] Next, we will explain the aging process after the battery has been manufactured. It is preferable to perform aging. An example of aging conditions is described below. First, Charge at a rate of 0.001C to 0.2C. The temperature should be, for example, above room temperature, 50°C. The temperature should be below °C. Here, the reaction potential of the positive or negative electrode exceeds the range of the potential window of electrolyte 508. In some cases, the electrolyte may decompose due to the charging and discharging of the battery. If more gas is generated, and that gas accumulates inside the cell, the electrolyte will come into contact with the electrode surface. This results in areas where this cannot be done. In other words, the effective reaction area of ​​the electrode decreases, and the effective reaction area This corresponds to an increase in resistance.

[0193] Furthermore, if the resistance becomes excessively high, the negative electrode potential decreases, causing lithium to penetrate the graphite. Simultaneously with the ingress, lithium deposition occurs on the graphite surface. This lithium deposition is This can lead to a decrease in quantity. For example, after lithium is deposited, a film or other substance may grow on the surface. As a result, lithium precipitated on the surface cannot be re-dissolved, and the amount of lithium that does not contribute to the volume increases. This can happen. Also, if the deposited lithium physically collapses and loses conductivity with the electrode, As a result, lithium that does not contribute to the capacity is produced. Therefore, the potential of the negative electrode increases the charging voltage. It is preferable to release the gas before reaching the lithium potential.

[0194] Furthermore, after degassing, the temperature should be higher than room temperature, preferably between 30°C and 60°C. More preferably, at a temperature of 35°C to 50°C, for example, for 1 hour to 100 hours. It may be held in an electrically charged state. During the initial charging, the electrolyte that decomposed on the surface is returned to the surface of the graphite. A coating is formed. Therefore, for example, by holding it at a temperature higher than room temperature after degassing, It is also possible that the formed coating may become denser.

[0195] Figure 7 shows an example of welding a current collector to a lead electrode. As shown in Figure 7(A), Separ The positive electrode 503 and negative electrode 506, encased in -507, are stacked alternately. Next, the positive electrode current collector... 501 is connected to the positive lead electrode 510, and the negative current collector 504 is connected to the negative lead electrode 511, respectively Welding is performed. An example of welding the positive electrode current collector 501 to the positive electrode lead electrode 510 is shown in Figure 7(B). The positive electrode current collector 501 is welded in a welding area 512 using ultrasonic welding or the like to form the positive electrode lead electrode 510 It is welded to it. In addition, the positive electrode current collector 501 has a curved portion 513 as shown in Figure 7(B). This allows for the mitigation of stress caused by external forces applied to the battery 500 after its manufacture. This can improve the reliability of the 500 battery.

[0196] In the battery 500 shown in Figures 4 and 5, the positive lead electrode 510 has a positive electrode 503 The positive electrode current collector 501 and the negative electrode lead electrode 511 are connected to the negative electrode current collector 504 of the negative electrode 506. Each is then ultrasonically bonded. Furthermore, the positive electrode acts as a terminal for obtaining electrical contact with the outside, collecting current. The body 501 and the negative electrode current collector 504 can also serve this purpose. In that case, lead electrodes are used. Without doing so, a portion of the positive electrode current collector 501 and the negative electrode current collector 504 are exposed to the outside from the outer casing 509. You can arrange them in this way.

[0197] Furthermore, in Figure 4, the positive lead electrode 510 and the negative lead electrode 511 are arranged on the same side. However, as shown in Figure 8, the positive lead electrode 510 and the negative lead electrode 511 are arranged on different sides. They may be placed there. Thus, in one aspect of the present invention, the storage battery allows the lead electrodes to be freely arranged. Because this is possible, the design flexibility is high. The degree of freedom in calculations can be increased. Furthermore, the productivity of products using a storage battery according to one embodiment of the present invention can be increased. It can be improved.

[0198] In the battery 500, the outer casing 509 is made of, for example, polyethylene, polypropylene, and Aluminum, S A highly flexible metal thin film such as stainless steel, copper, or nickel is provided, and an outer covering is further applied to the metal thin film. The outer surface of the body is provided with an insulating synthetic resin film such as polyamide resin or polyester resin. A layered film can be used.

[0199] Also, in Figure 5, 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; it can be more or fewer. Good. When the number of electrode active material layers is large, it is possible to create a storage battery with a larger capacity. Furthermore, when the number of electrode active material layers is small, the battery can be made thinner and have excellent flexibility. It is possible.

[0200] [Pre-dope] Here, we show an example of pre-doping the negative electrode 506 of the battery 500. Figure 9 (A) shows the top surface of a laminate in which the positive electrode, negative electrode and separator are stacked, and Figure 9(B) shows Figure 9 A perspective view of (A) is shown. Separator 507i is stacked on the negative electrode 506, and separator 507 A pre-doped positive electrode 503i is stacked on i, and a separator 507 is stacked on top of the positive electrode 503i. Then, the positive electrode 503 is stacked on the separator 507. Here, the separator 507i is a separator You can refer to the description of electrode 507. Also, positive electrode 503i is positive electrode active material It has a solid layer 502i and a positive electrode current collector 501i. Positive electrode 503i, positive electrode active material layer 502i The positive electrode current collector 501i consists of a positive electrode 503, a positive electrode active material layer 502, and a positive electrode current collector, respectively. You can refer to the description of body 501. Also, positive electrode 503 and positive electrode 503i are Different positive electrode active materials may be used.

[0201] Next, the laminates shown in Figures 9(A) and (B) are shown in the perspective view of Figure 10(A). It is then sandwiched between sheets 509a, which form the outer casing.

[0202] Next, as shown in the top view of Figure 10(B), three sides of sheet 509a are sealed by heat or other means. Then the outer casing 509 is formed, and a thin storage battery, the storage battery 500, is manufactured. Figure 10(B) Figure 11(A) shows a cross-sectional view of the battery shown in the direction of the dashed line B1-B2.

[0203] Next, pre-doping is performed using the negative electrode 506 and positive electrode 503i of the fabricated battery 500. Pre-doping may, for example, involve only charging, or it may involve both charging and discharging.

[0204] After pre-doping, one side of the outer casing 509 is cut and opened. Then, as shown in Figure 11(B As shown in the cross-sectional view of the opened outer casing 509, the positive electrode 503i and separator 5 Remove 07i. At this time, remove separator 507, not separator 507i. Alternatively, the separator 507i may be left in the battery 500 without being removed.

[0205] Subsequently, as shown in the cross-sectional view in Figure 11(C), the opened side of the outer casing 509 is sealed. The above process allows for pre-doping.

[0206] In Figures 9 to 11, the opposing positive electrode active material layer and negative electrode active material layer form a single field. Although an example of a combination was shown, when pre-doping is performed, the positive electrode active material layer and negative electrode active material layer are not a single set. It is not necessary. Figure 12 shows an example where three sets of positive electrode active material layers and negative electrode active material layers face each other. Figure 12 In (A), the positive electrode 503i is positioned between the opposing positive electrode 503 and negative electrode 506. First, pre-doping is performed using the positive electrode 503i and the negative electrode 506. Then, Figure 12(B) As shown, remove the positive electrode 503i, and as shown in Figure 12(C), remove the positive electrode active material layer and the negative electrode. This battery consists of three sets of polar active material layers facing each other.

[0207] In the above configuration, the battery casing 509 has a minimum radius of curvature of, for example, 3 mm or more. It can be deformed to be 0 mm or less, more preferably 3 mm to 10 mm or less. The film that forms the outer casing of the secondary battery consists of one or two layers, and has a laminated structure. In the case of a battery, the curved cross-sectional structure of the battery is sandwiched between two curves of the outer film. It will have a unique structure.

[0208] The radius of curvature of a surface will be explained using Figure 13. In Figure 13(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 13(B) shows a top view of the curved surface 1700. Figure 13(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.

[0209] A curved secondary battery was constructed using two films as an outer casing, sandwiching the electrodes, electrolyte, and other components of the 1805 battery. In this case, the radius of curvature 1802 of the film 1801 on the side closer to the center of curvature 1800 of the secondary battery. This is smaller than the radius of curvature 1804 of film 1803 on the side farther from the center of curvature 1800. Figure 14(A)). When the secondary battery 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 14(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 secondary battery has an outer casing that is 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.

[0210] Furthermore, the cross-sectional shape of a secondary battery is not limited to a simple arc shape, but can also have a shape in which part of it is an arc. It is possible to create shapes such as the one shown in Figure 14(C), or wavy (Figure 14(D)), or S-shaped. It is also possible to do so. If the curved surface of the secondary battery has a shape with multiple centers of curvature, Among the radii of curvature at each of the number of curvature centers, in the surface with the smallest radius of curvature, 2 For example, the smallest radius of curvature of the outer casing closest to the center of curvature of the individual casings is between 3 mm and 30 mm. The material can be deformed to be more preferably 3 mm or more and 10 mm or less.

[0211] Next, various examples of stacking of positive, negative, and separator electrodes are shown.

[0212] Figure 17(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.

[0213] Furthermore, in the configuration shown in Figure 17(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.

[0214] Therefore, when the storage battery 500 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 storage battery. When 500 is curved, the outer casing 509 of the battery 500 is located inside the curved portion. This refers to the radius of curvature of the surface. Therefore, it can suppress the degradation of the battery 500. Furthermore, it can be used as a highly reliable battery 500.

[0215] Furthermore, Figure 17(B) shows an example of stacking of positive electrode 111 and negative electrode 115 that differs from that shown in Figure 17(A). In the configuration shown in Figure 17(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 17(A). As shown in Figure 17(B), the positive electrode current collector By providing positive electrode active material layers 122 on both sides of 121, the capacity per unit volume of the storage battery 500 The quantity can be increased.

[0216] Furthermore, Figure 17(C) shows an example of stacking of positive electrode 111 and negative electrode 115 that differs from that shown in Figure 17(B). In the configuration shown in Figure 17(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 17(B). As shown in Figure 17(C), the negative electrode current collector By providing negative electrode active material layers 126 on both sides of 125, the capacity per unit volume of the storage battery 500 The quantity can be increased even further.

[0217] Furthermore, in the configuration shown in Figure 17, the separator 123 encloses the positive electrode 111 in a bag-like manner. However, the present invention is not limited thereto. Here, Figure 18(A) is shown, and Figure 17(A) is shown. Examples of separators 123 with different configurations are shown. In the configuration shown in Figure 18(A), the positive electrode is active A sheet-like separator 123 is provided between the material layer 122 and the negative electrode active material layer 126. In this respect, it differs from the configuration shown in Figure 17(A). In the configuration shown in Figure 18(A), The electrodes 111 and negative electrodes 115 are stacked in six layers each, and six layers of separators 123 are provided.

[0218] Figure 18(B) also shows an example in which a different separator 123 is provided compared to Figure 18(A). In the configuration shown in 18(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 multiple times so as to be sandwiched between layers 126, as shown in Figure 18(A) The configuration is different. Also, the configuration in Figure 18(B) is different from the configuration in Figure 18(A) in terms of the separation of each layer. It can also be described as a configuration where Ta 123 is extended and the layers are connected. This is shown in Figure 18(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 necessary to fold it back at least five times. Also, the separator 123 is connected to the positive electrode active material layer 122. In addition to being positioned between the negative electrode active material layers 126, it is also extended to accommodate multiple positive electrodes 111 The negative electrode 115 may be bundled together with the other electrodes.

[0219] Alternatively, the positive electrode, negative electrode, and separator may be stacked as shown in Figure 19. Figure 19(A) Figure 19(B) is a cross-sectional view of the first electrode assembly 130, and Figure 19(B) is a cross-sectional view of the second electrode assembly 131. Figure 19(C) is a cross-sectional view along the dashed line A1-A2 in Figure 4. Note that in Figure 19(C) To clarify the diagram, the first electrode assembly 130, the second electrode assembly 131 and the separator are shown. Here is an excerpt from DATA 123.

[0220] As shown in Figure 19(C), the storage battery 500 has multiple first electrode assemblies 130 and multiple It has a second electrode assembly 131.

[0221] As shown in Figure 19(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 19( 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.

[0222] Furthermore, as shown in Figure 19(C), there are multiple first electrode assemblies 130 and multiple second The electrode assembly 131 is covered by a wound separator 123.

[0223] [Coin-type rechargeable battery] Next, as an example of an energy storage device, we will explain an example of a coin-type battery with reference to Figure 15. Figure 15(A) is an external view of a coin-type (single-layer flat-type) storage battery, and Figure 15(B) is This is a cross-section of it.

[0224] 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.

[0225] 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.

[0226] For positive electrode 304, refer to the description for positive electrode 503. For positive electrode active material layer 306, Refer to layer 502. For negative electrode 307, refer to negative electrode 506. Negative electrode active material For layer 309, refer to the description of negative electrode active material layer 505. Separator 310 is separate Refer to the description in -507. For the electrolyte, refer to the description in Electrolyte 508.

[0227] Furthermore, the positive electrode 304 and negative electrode 307 used in the coin-type storage battery 300 are each live metal The layer only needs to be formed on one side.

[0228] 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.

[0229] These negative electrode 307, positive electrode 304, and separator 310 are impregnated with the electrolyte, as shown in Figure 15. 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.

[0230] [Cylindrical storage battery] Next, as an example of an energy storage device, a cylindrical battery is shown. Figure 16 shows the cylindrical battery. Refer to the following for explanation. The cylindrical storage battery 600 has a positive electrode on its top surface, as shown in Figure 16(A). It has a cap (battery cover) 601 and battery cans (outer cans) 602 on the sides and bottom. These positive electrode caps 601 and battery can (outer can) 602 are connected by a gasket (insulating packing). It is insulated by (n)610.

[0231] 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. The 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.

[0232] Positive electrode 604 should refer to positive electrode 503. Similarly, negative electrode 606 should refer to negative electrode 506. This is sufficient. Furthermore, the positive electrode 604 and the negative electrode 606 can be manufactured as shown in the first embodiment. The method can be referenced. The positive and negative electrodes used in cylindrical storage batteries are wound, It is preferable to form the active material on both sides of the current collector. The positive electrode 604 has a positive electrode terminal (positive electrode current collector The negative terminal (negative current collector lead) 607 is connected to the negative terminal 606. The positive terminal 603 and the negative terminal 607 are both made of metal materials such as aluminum. The positive terminal 603 is connected to the safety valve mechanism 612, and the negative terminal 607 is connected to the battery can 602. The bottom of each is resistance welded. The safety valve mechanism 612 has a PTC element (Positive Positive electrode cap 601 via Temperature Coefficient 611 It is electrically connected to the battery. The safety valve mechanism 612 activates when the internal pressure of the battery exceeds a predetermined threshold. In some cases, this disconnects the electrical connection between the positive electrode cap 601 and the positive electrode 604. The PTC element 611 is a thermal resistance element whose resistance increases when the temperature rises, and the resistance is The increased current limits the amount of current and prevents abnormal heat generation. The PTC element contains titanate. Barium (BaTiO3)-based semiconductor ceramics can be used.

[0233] 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.

[0234] In this embodiment, coin-type, cylindrical, and thin-type rechargeable batteries are shown. However, various types of batteries, such as sealed batteries and prismatic batteries, can be used. Furthermore, a structure in which multiple positive electrodes, negative electrodes, and separators are stacked, positive electrodes, negative electrodes, and separators The structure may also be one in which the data is wound. For example, other examples of storage batteries are shown in Figures 20 to 24. vinegar.

[0235] [Example configuration of a slim battery storage system] Figures 20 and 21 show examples of the configuration of a thin storage battery. The wound body 99 shown in Figure 20(A) 3 has a negative electrode 994, a positive electrode 995, and a separator 996.

[0236] The wound body 993 has the negative electrode 994 and the positive electrode 995 overlapping with the separator 996 in between. The laminated sheets are stacked and then wound up. This wound body 993 is placed in a rectangular sealed container. By covering it with a material, a rectangular secondary battery is created.

[0237] The number of layers in the stack consisting of the negative electrode 994, positive electrode 995, and separator 996 is required. The design should be appropriate depending on the capacitance and element volume. The negative electrode 994 is connected to the lead electrode 997 and One end of electrode 998 is connected to a negative electrode current collector (not shown), and positive electrode 995 is connected to a lead The electrode 997 and the other lead electrode 998 are connected to a positive electrode current collector (not shown). .

[0238] The storage battery 990 shown in Figures 20(B) and 20(C) is enclosed by a film 981. The space formed by bonding the film 982 having a recess to the above by heat-pressing or the like This houses the wound body 993 described above. The wound body 993 contains the lead electrode 997 and It has a hard electrode 998 and electrolysis occurs inside the film 981 and the film 982 which has a recess. It is impregnated with liquid.

[0239] Film 981 and film 982 having a recess are made of a metal material such as aluminum. Materials and resins can be used. Film 981 and film 982 having recesses If a resin material is used as the material, when an external force is applied, the film 981 and the recess will be affected. The film 982 having the property can be deformed, and a flexible storage battery can be manufactured. It is possible.

[0240] Furthermore, Figures 20(B) and 20(C) show examples where two films are used. By folding a single film, a space is formed, and the aforementioned wound body 9 is placed in that space. You may store 93.

[0241] Furthermore, by making the outer casing and sealing container of the energy storage device from resin material, flexibility is achieved. It is possible to manufacture an energy storage device. However, if the outer casing or sealing container is made of resin material, The parts that connect to the outside will be made of conductive material.

[0242] For example, Figure 21 shows an example of another thin, flexible battery. Figure 21(A) shows the wound body 9 Since 93 is identical to the one shown in Figure 20(A), a detailed explanation will be omitted. .

[0243] The storage battery 990 shown in Figures 21(B) and 21(C) is located inside the outer casing 991 as described above. This houses the wound body 993. The wound body 993 contains the lead electrode 997 and lead It has an electrode 998 and is impregnated with an electrolyte inside the outer casings 991 and 992. Outer casing 991, 992 can be made of metal materials such as aluminum or resin materials. If resin material is used as the material for 991 and 992, when an external force is applied, the outer casing 9 By deforming 91 and 992, a flexible, thin storage battery can be fabricated. ru.

[0244] An electrode containing an active material according to one aspect of the present invention is used in a flexible, thin storage battery. Furthermore, even if stress is applied to the electrodes by repeatedly bending the thin battery, This prevents the material from cleaving.

[0245] Therefore, using an active material in which at least a portion of the cleavage surface is covered with graphene as an electrode... This makes it possible to suppress the drop in battery voltage and the decrease in discharge capacity. This can improve the battery's cycle characteristics during charging and discharging.

[0246] [Example of an energy storage system structure] Furthermore, an example of the structure of an energy storage system will be explained using Figures 22 to 24. An electrical system refers to, for example, equipment equipped with an energy storage device.

[0247] Figures 22(A) and 22(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 22(B), the energy storage system has terminal 951 and It has terminal 952, antenna 914, and antenna 915.

[0248] 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.

[0249] 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.

[0250] 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.

[0251] 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 do so. For layer 916, for example, a magnetic material can be used.

[0252] Note that the structure of the energy storage system is not limited to the structure shown in Figure 22.

[0253] For example, as shown in Figures 23(A-1) and 23(A-2), Figure 22(A) and In the battery 913 shown in Figure 22(B), antennas are provided on each of the two opposing sides. It is also possible. Figure 23(A-1) is an external view of the pair of surfaces as seen from one side, and Figure 2 3(A-2) is an external view of the pair of surfaces as seen from the other side. Note that Figure 22(A) And for the same parts as the energy storage system shown in Figure 22(B), see Figures 22(A) and 2 The explanation of the energy storage system shown in 2(B) can be used as appropriate.

[0254] As shown in Figure 23(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 23(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.

[0255] By adopting the above structure, the size of both antenna 914 and antenna 915 can be increased. It is possible to hear.

[0256] Alternatively, as shown in Figures 23(B-1) and 23(B-2), Figure 22(A) and Of the battery 913 shown in Figure 22(B), a separate antenna is attached to each of the two opposing sides. It may be provided. Figure 23(B-1) is an external view of the pair of surfaces as seen from one side. Figure 23(B-2) is an external view of the pair of surfaces as seen from the other side. Note that Figure 22( For the same parts as the energy storage system shown in A) and Figure 22(B), see Figure 22(A) and The explanation of the energy storage system shown in Figure 22(B) can be used as appropriate.

[0257] As shown in Figure 23(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 23(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.

[0258] Alternatively, as shown in Figure 24(A), the storage battery 91 shown in Figures 22(A) and 22(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. Note that the same parts as the energy storage system shown in Figures 22(A) and 22(B) In this regard, the explanation of the energy storage system shown in Figures 22(A) and 22(B) can be appropriately referenced.

[0259] 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.

[0260] Alternatively, as shown in Figure 24(B), the storage battery 91 shown in Figures 22(A) and 22(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 22(A) and 22(B). For details, please refer to the explanation of the energy storage system shown in Figures 22(A) and 22(B) as appropriate. Cut.

[0261] 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. .

[0262] 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.

[0263] This embodiment can be implemented in appropriate combination with other embodiments.

[0264] (Embodiment 3) This embodiment describes an example of mounting a flexible energy storage device in an electronic device. .

[0265] Figure 25 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.

[0266] Furthermore, energy storage devices with flexible shapes can be installed in the interior or exterior walls of houses and buildings, or in automated systems. It can also be integrated to conform to the curved surfaces of the car's interior or exterior.

[0267] Figure 25(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.

[0268] Figure 25(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 25 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.

[0269] Figure 25(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 25(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.

[0270] Figure 25(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.

[0271] 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.

[0272] 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.

[0273] 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.

[0274] 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.

[0275] 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.

[0276] The display unit 7202 of the portable information terminal 7200 is equipped with an energy storage device comprising electrodes according to one aspect of the present invention. It has, for example, the energy storage device 7104 shown in Figure 25(E) inside the housing 7201. It can be incorporated in a curved state, or in a flexible state inside the band 7203. ru.

[0277] 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.

[0278] Figure 25(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.

[0279] 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.

[0280] 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.

[0281] This embodiment can be implemented in appropriate combination with other embodiments.

[0282] (Embodiment 4) This embodiment shows an example of an electronic device that can be equipped with an energy storage device.

[0283] Figures 26(A) and 26(B) show an example of a foldable tablet device. The tablet terminal 9600 shown in Figures 26(A) and 26(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 26(A) shows the tablet terminal 9600 opened. Figure 26(B) shows the state in which the tablet terminal 9600 is closed.

[0284] 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.

[0285] 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.

[0286] 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.

[0287] Furthermore, simultaneously with respect to the touch panel area 9632a and the touch panel area 9632b You can also use touch input.

[0288] 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 unit.

[0289] Furthermore, Figure 26(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".

[0290] Figure 26(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 the power body 9635, a power storage body according to one aspect of the present invention is used.

[0291] 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.

[0292] In addition, there are various other tablet devices, as shown in Figures 26(A) and 26(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.

[0293] 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.

[0294] Furthermore, the configuration and operation of the charge / discharge control circuit 9634 shown in Figure 26(B) are shown in Figure 26. (C) shows a block diagram and provides an explanation. Figure 26(C) shows the solar cell 9633 and the energy 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 26(B) This corresponds to the section for 634.

[0295] 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.

[0296] 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.

[0297] Figure 27 shows an example of another electronic device. In Figure 27, 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.

[0298] 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.

[0299] 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.

[0300] In Figure 27, 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 27, 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.

[0301] Figure 27 illustrates a fixed lighting device 8100 installed on the ceiling 8104. 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.

[0302] 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.

[0303] In Figure 27, 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 27) 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.

[0304] Figure 27 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.

[0305] In Figure 27, 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 27, 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.

[0306] 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.

[0307] 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.

[0308] This embodiment can be implemented in appropriate combination with other embodiments.

[0309] (Embodiment 5) This embodiment shows an example in which a power storage device is installed in a vehicle.

[0310] 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.

[0311] Figure 28 illustrates a vehicle using one aspect of the present invention. The automobile shown in Figure 28(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.

[0312] 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.

[0313] The automobile 8500 shown in Figure 28(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 28(B) shows the power from the ground-mounted charging device 8021 to the vehicle 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.

[0314] 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.

[0315] 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.

[0316] This embodiment can be implemented in appropriate combination with other embodiments.

[0317] (Embodiment 6) 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 29 to 35. 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.

[0318] When multiple battery cells connected in series are repeatedly charged and discharged, the space between the battery cells As a result, variations occur in charge and discharge characteristics, causing the capacity (output voltage) of each battery cell to differ. In a series connection of multiple battery cells, the total discharge capacity is reduced by the capacity of the smallest battery cell. It depends. If there is variation in the capacity of each battery cell, the overall capacity during discharge will be smaller. Furthermore, if charging is performed based on a battery cell with a smaller capacity, there is a risk of insufficient charging. Charging based on a large number of battery cells may lead to overcharging.

[0319] 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.

[0320] 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.

[0321] 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. .

[0322] Now, let's discuss the CAAC-OS membrane.

[0323] CAAC-OS film is an oxide semiconductor film having multiple c-axis oriented crystalline regions. .

[0324] 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.

[0325] 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.

[0326] 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.

[0327] 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.

[0328] 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.

[0329] 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.

[0330] 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.

[0331] 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 process 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.

[0332] Furthermore, transistors using CAAC-OS films exhibit electrical properties when irradiated with visible light or ultraviolet light. Sexual variation is small.

[0333] 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, In energy storage devices, the circuit configuration of the battery control unit applied to such battery cells includes the following: It is suitable to construct it using the OS transistors described above.

[0334] Figure 29 shows an example of a block diagram of an energy storage device. The energy storage device BT00 shown in Figure 29 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.

[0335] Furthermore, in the energy storage device BT00 shown in Figure 29, 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.

[0336] 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.

[0337] 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.

[0338] 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.

[0339] This section describes the operation of the switching control circuit BT03 in detail.

[0340] 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).

[0341] 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. It may also be possible to determine whether 09 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.

[0342] 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.

[0343] Here, an example of the operation of the switching control circuit BT03 in this embodiment will be explained using Figure 30. To clarify, Figure 30 is a diagram illustrating an example of the operation of the switching control circuit BT03. For the sake of explanation, Figure 30 shows an example where four BT09 battery cells are connected in series. explain.

[0344] First, in the example shown in Figure 30(A), the voltages of battery cells a to d are defined as voltages Va to 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.

[0345] Next, the example in Figure 30(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.

[0346] Finally, the example in Figure 30(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.

[0347] The switching control circuit BT03 is determined as shown in the examples in Figures 30(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.

[0348] The above is a detailed explanation of the operation of the switching control circuit BT03.

[0349] 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.

[0350] 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.

[0351] 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.

[0352] 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.

[0353] Figures 31 and 31 show circuit diagrams illustrating example configurations of switching circuits BT04 and BT05. This is shown in 32.

[0354] In Figure 31, 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.

[0355] 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.

[0356] 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 A2. 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.

[0357] 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 large. 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.

[0358] Furthermore, in Figure 31, 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.

[0359] 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.

[0360] 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. .

[0361] 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.

[0362] 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.

[0363] 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.

[0364] The switching circuit BT05, as an example, connects the rechargeable battery cell group and terminal pair BT as follows. Connect to 02.

[0365] 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.

[0366] 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.

[0367] 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.

[0368] Furthermore, the current control switch BT14 is not the switching circuit BT05, but the switching circuit B It may be included in T04.

[0369] Figure 32 shows the configuration of switching circuits BT04 and BT05, which differs from that of Figure 31. This is a circuit diagram illustrating an example.

[0370] In Figure 32, 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 end of each pair of transistors BT21 is connected to two adjacent battery cells BT09. It is connected in between. Of the multiple transistor pairs BT21, the one located at the uppermost position The other end of the transistor pair BT21 is connected to the battery cell BT09, which is located at the uppermost part of the battery section BT08. It is connected to the positive terminal. Also, it is located at the downstream end of the multiple transistor pairs BT21. The other end of the transistor pair BT21 is connected to the battery cell BT located at the downstream end of the battery section BT08. It is connected to the negative terminal of 09.

[0371] 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.

[0372] 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.

[0373] 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.

[0374] 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.

[0375] 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 cells are connected to the BT02 terminal pair. 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.

[0376] 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.

[0377] 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 generates the signal and outputs it to the transformer circuit BT07.

[0378] 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.

[0379] 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.

[0380] 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).

[0381] Here, an example of the operation of the transformer control circuit BT06 in this embodiment is shown in Figures 33(A) to (C) This will be explained using Figures 30(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 33(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.

[0382] In the example shown in Figure 33(A), as explained in Figure 30(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 30( 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).

[0383] 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 33(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.

[0384] 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 is 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.

[0385] In the example shown in Figure 33(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.

[0386] Furthermore, in the examples shown in Figures 33(B) and 33(C), the conversion ratio is the same as in Figure 33(A). N is calculated. In the examples shown in Figures 33(B) and 33(C), the discharge battery cell group is included 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.

[0387] 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.

[0388] 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.

[0389] 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.

[0390] Figure 34 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.

[0391] The processing flow of the energy storage device BT00 in this embodiment will be explained using Figure 35. Figure 3 Figure 5 is a flowchart showing the processing flow of the energy storage device BT00.

[0392] 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.

[0393] Also, although the flowchart in Figure 35 shows multiple steps in order, each step The execution order of the steps is not limited to the order in which they are listed.

[0394] 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.

[0395] 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, markings are made on the terminal pair BT01. The applied discharge voltage is converted into a charging voltage and applied to the terminal pair BT02. Regardless of how the BT09 battery cells on the charging and discharging sides are selected, charge transfer is performed without any problems. It can be expressed.

[0396] 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.

[0397] This embodiment can be implemented in appropriate combination with other embodiments. [Examples]

[0398] In this example, cyclic voltammetry (CV) measurement of the electrolyte was performed.

[0399] Four types of electrolytes are prepared: Electrolyte A-1, Electrolyte A-2, Electrolyte A-3, and Electrolyte A-4. It was prepared. All four types of electrolytes use EMI-FSA (1-ethyl-3-methylimi) as the solvent. Dazolium bis(fluorosulfonyl)amide was used. Electrolyte A-2, Electrolyte A-3 And in electrolyte A-4, LiFSA (lithium bis(fluorosulfone)) is used as the electrolyte. Nylamide was used. Electrolyte A-1 did not use an electrolyte. Electrolyte The concentrations are 1 mol / L in electrolyte A-2 and 0.1 mol / L in electrolyte A-3. The electrolyte A-4 was adjusted to 0.01 mol / L.

[0400] The reference electrode was lithium, the working electrode was copper, and the counter electrode was platinum. The area of ​​the working electrode was 0.02c². m 2 The electrolyte for the reference electrode was PP13-TFSA(N-methyl-N- Using propylpiperidinium bis(trifluoromethanesulfonyl)amide, LiTFSA (lithium bis(trifluoromethanesulfonyl)amide) is used as the basis. The electrolyte concentration in the electrolyte solution was set to 0.4 mol / L.

[0401] The scanning speed was set to 50 mV / sec., and the voltage range was set to 3 V to -0.5 V. Electrolyte A -1, Figure 36(A) shows the CV measurement results for electrolytes A-2, A-3, and A-4. (B), shown in Figures 37(A) and (B). The horizontal axis is Li / Li + Potential relative to, vertical axis This indicates the current density.

[0402] In electrolyte A-1, which does not use lithium salts, a reduction current of approximately 0.7V was observed, and EM The reduction reaction of I-FSA was suggested. In electrolyte A-2, the level observed in electrolyte A-1 was 0.7 The reduction current near V is suppressed, and the reduction current and oxidation current near 0V are observed, respectively. This was suggested to correspond to lithium deposition and lithium leaching. In electrolyte A-2, Lithium ions form an electrical double layer on the electrode surface, EMI cations, and FS It is thought that the reduction reaction of one or both of the A anions was suppressed.

[0403] In electrolyte A-3, no significant reduction current was observed near 0V, indicating suppression of EMI decomposition. Although suggested, no oxidation current indicating lithium deposition was observed. On the other hand, electrolysis In solution A-4, a reduction current was observed at a potential higher than 0V, and EMI cations and FS were detected. It was suggested that reduction reactions of one or both of the A anions occur.

[0404] Figures 38(A) and (B) show the second and third cycles in electrolyte A-4. The CV measurement results are shown. The waveforms of the CV measurements for the 2nd and 3rd cycles are lithium The waveform obtained from the CV measurement of electrolyte A-1, which does not use salt, was almost identical to that obtained from electrolyte A-4. In this case, the lithium salt concentration is low, and an electrical double layer cannot be sufficiently formed on the electrode surface, E It is thought that the concentration of lithium salt is insufficient to suppress the reduction reaction of MI cations, etc. ru.

[0405] Furthermore, in electrolyte A-4, the sweep rate was set to 0.5 mV / sec. and the voltage range to 3V. By performing CV measurements with the voltage set to -0.3V, it was found that the reduction reaction was suppressed. The results are shown in Figure 39.

[0406] Next, electrolytes A-5 and A-6 were prepared. In this study, EMI-TFSA was used as the solvent and LiTFSA as the electrolyte. The electrolyte concentration in the solution is 1 mol / L in electrolyte A-5 and 1 mol / L in electrolyte A-6. The concentration was adjusted to 2 mol / L.

[0407] Figure 40 shows that in electrolyte A-5, the insertion / withdrawal speed is 0.5 mV / s and the voltage range is from 3V - 0.15V, Figure 41(A) shows that in electrolyte A-6, the insertion / withdrawal speed is 0.5mV / s, and the voltage is... The range is 3V to 0V, and in Figure 41(B), the insertion / withdrawal speed is 0.1mV / The results for s and for voltage ranges from 3V to 0V are shown. The lithium salt concentration was 2 mol / In electrolyte A-6, defined as L, a peak suggesting lithium elution was observed and formed. It is possible that the reduction reaction of EMI cations and other substances was suppressed by the electric double layer. [Examples]

[0408] In this example, a rechargeable battery was fabricated and the charge-discharge cycle was measured.

[0409] First, electrolytes A-7 and AC-1 were prepared. In electrolyte A-7, B was used as the solvent. MI-FSA is used, LiFSA is used as the electrolyte, and the electrolyte concentration relative to the electrolyte solution is 1 The concentration was set to 0.5 mol / L. In the comparative electrolyte, electrolyte AC-1, EC and DEC were used as solvents. A solvent mixture with a volume ratio of EC:DEC = 3:7 was used, and LiPF6 was used as the electrolyte. The electrolyte concentration in the electrolyte solution was set to 1 mol / L.

[0410] [Electrode fabrication] Next, negative electrode E1, positive electrode E2, and positive electrode E3 were prepared.

[0411] The formulation and manufacturing method of the negative electrode E1 will be described. The active material is carbon-coated Si O was used as the binder, polyimide as the binder, and acetylene black as the conductive additive. The slurry composition for preparing the electrodes is SiO:acetylene black:polyimide = The ratio was set to 80:5:15 (by weight %).

[0412] First, acetylene black and the solvent NMP are mixed using a kneader to form the first mixture. I obtained a suitable product.

[0413] Next, an active material was added to the first mixture to obtain a second mixture.

[0414] Next, the NMP solution of polyimide was added to the second mixture and kneaded using a kneader. The slurry was prepared using the above process.

[0415] Next, the prepared slurry was applied to one side of a stainless steel current collector with a thickness of 10 μm. A continuous coating machine was used for application, with an application speed of 0.15 m / min. Afterwards, a drying oven was used. The material was then dried. The drying conditions were 40°C for 20 minutes.

[0416] Next, the fabricated electrodes were heat-treated and imidized. A muffle furnace was used for the heat treatment. The thermal conditions involved treatment at 400°C for 5 hours in a nitrogen atmosphere. Through the above process, the negative electrode was processed. I made it.

[0417] Next, positive electrodes E2 and E3 were prepared.

[0418] The formulation and manufacturing conditions for the positive electrode E2 will be described. The active material is Li with an average particle size of 10 μm. CoO2 is used, PVdF is used as a binder, and acetylene black is used as a conductive additive. The slurry mixture for preparing the electrodes was LiCoO2:Acetylene Black:P VdF = 90:5:5 (weight %)

[0419] The active material, binder, and conductive additive were mixed together to prepare a slurry. It was coated on one side of a 20 μm thick aluminum current collector. The solvent was then evaporated. Next, the positive electrode... The active material layer was pressed. The positive electrode E2 was fabricated through the above process.

[0420] The formulation and manufacturing conditions for the positive electrode E3 will be described. The active material has a specific surface area of ​​15.6 m². 2 / g LiFePO4 is used as the binder, PVdF as the binder, and acetylene bran as the conductive additive. A smear was used. The slurry formulation for preparing the electrodes was LiFePO4:acetylene Rack: PVdF = 85:8:7 (weight %).

[0421] First, acetylene black and the binder PVdF are mixed using a kneader, and the first A mixture was obtained.

[0422] Next, an active material was added to the first mixture to obtain a second mixture.

[0423] Next, NMP, a solvent, was added to the second mixture and kneaded using a kneader. A slurry was prepared according to the instructions.

[0424] Next, the mixture was kneaded using a large mixing machine.

[0425] Next, the prepared slurry is placed in a 20 μm thick aluminum slab that has been pre-coated with an undercoat. The coating was applied to one side of the current collector. A continuous coating machine was used for the coating, and the coating speed was 0.2 m / min. Then, the solvent was evaporated using a drying oven. The conditions for the drying oven were 70°C for 7.5 minutes. After the initial treatment, the sample was subjected to further treatment at 90°C for 7.5 minutes.

[0426] Next, the positive electrode active material layer was compacted by pressing it using a roll press method. Then, the positive electrode E3 was fabricated.

[0427] [Battery manufacturing] Next, cut the negative electrode E1, positive electrode E2, and positive electrode E3, and insert the lead electrodes into the tab regions respectively. The parts were bonded by welding. The area of ​​the negative electrode E1 is 23.8 cm². 2 Area of ​​positive electrode E2 and positive electrode E3 20.5cm 2 That's what I decided.

[0428] Next, the negative electrode E1 and the positive electrode E2 are placed facing each other with a first separator in between, and A second separator was placed on the positive electrode E2, and the positive electrode E3 was placed on the second separator. Between the positive electrode E3 and the negative electrode E1, from the side closer to the positive electrode E3, there is a second separator and a positive electrode. E2 and the first separator are arranged. The separator is a 40 μm thick separator. I used a TF40 made by Lurose.

[0429] As a sheet to form the exterior, a sheet made of aluminum coated with resin on both sides was used. Prepared. Stacked negative electrode E1, first separator, positive electrode E2, second separator and positive A laminate consisting of pole E3 was wrapped in the sheet, which had been folded in half.

[0430] Next, two of the three sides of the folded sheet are sealed with heat to form the outer casing. The ends of the lead electrodes attached to each electrode were positioned outside the sheet. Then, it was dried at 80°C.

[0431] Next, under a reduced pressure atmosphere of -60kPa or less, electrolysis is performed from the unsealed side of the outer casing. The electrolyte was poured in. The amount of electrolyte poured was approximately 0.6 ml. A storage battery using electrolyte A-7 was then installed. Battery BA and a comparative battery using electrolyte AC-1 are designated as battery BC.

[0432] The loading amounts of the negative electrode E1, positive electrode E2, and positive electrode E3 used in the BA battery were 2.0 mg / cm³. 2 , 20 mg / cm³ 2 , and 9.3 mg / cm³ 2 The density was 0.55 g / cm³. c was approximately 2.2 g / cc and 1.0 g / cc.

[0433] The loading amounts of negative electrode E1, positive electrode E2, and positive electrode E3 used in battery BC were 2.0 mg / cm³. 2 , 20 mg / cm³ 2 and 9.4 mg / cm³ 2 The density was 0.63 g / cc. The concentrations were 2.1 g / cc and 1.1 g / cc. Here, the loading amount refers to the amount per unit area. This refers to the weight of the active material.

[0434] Next, the unsealed edges were sealed using heat. The battery was manufactured through these steps. .

[0435] [Pre-dope] Constant current charging was performed at 25°C, using positive electrode E2 as the positive electrode and negative electrode E1 as the negative electrode. The charging conditions are a current density of 17.9 mA / g (approximately 0.01 C relative to the negative electrode active material capacity). The battery was set to 600mAh / g and charged to that level. A 0.5-hour rest period was allowed after charging.

[0436] After charging, one side of the casing was cut. Then, from the cut side, the positive electrode E2 and The second separator was removed.

[0437] Next, electrolyte A-7 is added to battery BA, and electrolyte AC-1 is added to battery BC, each to 0 0.3 ml was injected.

[0438] Next, the cut and opened edges were sealed using heat.

[0439] [aging] Next, the aging process was performed. First, at 25°C, the positive electrode was set to positive electrode E3 and the negative electrode to negative electrode E As a first step, constant current charging was performed. The charging conditions were a current density of 1.7 mA / g (positive electrode active material capacity). The current was set to approximately 0.01C relative to the amount, and the upper voltage limit was set to 3.2V. The rest period after charging was set. We allocated two hours.

[0440] After charging, one side of the casing was cut to release the gas. Then, it was cut open. The edges were sealed with heat.

[0441] Next, the current density is set to 8.5 mA / g (equivalent to approximately 0.05 C), and the upper voltage limit is set to 4 V. Current charging was performed. Afterward, the current density was set to 34 mA / g (equivalent to approximately 0.2 C), and the lower limit voltage was set. Constant current discharge was performed with a voltage of 2V. A rest period of 2 hours was set after both charging and discharging. keta.

[0442] Next, two cycles of constant current charging and discharging were performed with a current density of 34 mA / g. The charge and discharge curves of the Kuru are shown in Figure 42. The solid line in the figure represents the first charge and discharge, and the dotted line represents the second charge and discharge. Figure 42(A) shows the charge-discharge cycle of battery BC, and Figure 42(B) shows the charge-discharge cycle of battery BA. These are shown below. The upper limit voltage for charging was set to 4V, and the lower limit voltage for discharging was set to 2V. After charging and discharging... Each step included a two-hour break. The above process constituted the aging process.

[0443] [Charge-discharge cycle] The charge-discharge cycle characteristics of batteries BA and BC that underwent the aging process were examined. The evaluation was conducted with a constant current, with a current density of 51 mA / g (equivalent to approximately 0.3 C) for charging and discharging. The test was conducted as follows: The upper limit voltage for charging was set to 4V, and the lower limit voltage for discharging was set to 2V. Each test included a 0.5-hour rest period. Figure 43 shows the charge-discharge cycle characteristics. The horizontal axis represents the charge cycle. The vertical axis represents the number of cycles, and the vertical axis represents the discharge capacity. For the BC battery, the discharge capacity is shown after 500 cycles. While the initial discharge capacity decreased to approximately 60%, the BA battery lasted for 500 cycles. The discharge capacity in this case is more than 80% of the initial discharge capacity, demonstrating excellent charge-discharge cycle characteristics. It was discovered that... [Examples]

[0444] Regarding the storage batteries BA and BC prepared in Example 2, after charging and discharging... XPS analysis was performed on the surface of the negative electrode.

[0445] After the charge-discharge cycle, batteries BA and BC were dismantled. Following dismantling, deuterium replacement was performed. Acetonitrile was added and mixed with the electrolyte remaining in the battery, and the mixture was extracted using a pipette. Then, the negative electrode was immersed in DMC placed in a petri dish and washed. The DMC was replaced twice, total Three washes were performed. Afterward, the solvent was evaporated under reduced pressure.

[0446] Next, XPS analysis was performed on the negative electrodes of battery BA and battery BC. C, O, Table 1 shows the atomic percentages of F, S, Li, P, N, Al, and Si.

[0447] [Table 1]

[0448] Figure 44(A) shows C1s, Figure 44(B) shows O1s, Figure 45(A) shows F1s, Figure 45 Figure (B) shows the spectrum of S2p, and Figure 46 shows the spectrum of Li1s.

[0449] A significant difference was observed at the S2p peak. At the negative electrode of the battery BA, S The Ox peak was more than three times greater than the metal-S peak. [Examples]

[0450] Regarding the storage batteries BA and BC prepared in Example 2, after charging and discharging... The cross-section of the negative electrode was observed.

[0451] After the charge-discharge cycle, batteries BA and BC were dismantled. Following dismantling, deuterium replacement was performed. Acetonitrile was added and mixed with the electrolyte remaining in the battery, and the mixture was extracted using a pipette. Then, the negative electrode was immersed in DMC placed in a petri dish and washed. The DMC was replaced twice, total Three washes were performed. Afterward, the solvent was evaporated under reduced pressure.

[0452] Next, to observe the cross-section of the negative electrode, thinning was performed using FIB. After that, TEM was used. The cross-section of the negative electrode was observed using [a specific method / tool]. Observation results of the negative electrodes of batteries BC and BA. This is shown in Figures 47 and 48.

[0453] Next, STEM observation of the negative electrode cross-section was performed, and elemental analysis was conducted using STEM-EDX line analysis. The analysis was performed on a total of six elements: carbon, oxygen, fluorine, silicon, phosphorus, and sulfur. Figure 49(A) shows the STEM image of the area where line analysis was performed on the battery BC. The spectra of the analysis are shown in Figures 49(B) and 51(A). For battery BA, the line segment Figure 50(A) shows the STEM image of the area where the analysis was performed, and Figure 50(A) shows the spectrum of the obtained line analysis. This is shown in Figure B) and Figure 51(B). Here, the vertical axis in Figures 49(B) and 50(B) represents the signal strength. The degree is shown. Also, the vertical axis in Figures 51(A) and 51(B) represents the abundance of each element in units. This is shown as atomic%.

[0454] In Figures 49(B) and 51(A), the region from the surface to approximately 0.2 μm is the third region. This region is defined as [region name]. Furthermore, the region from near 0.2 μm to near 0.45 μm is defined as the second region. Furthermore, the region deeper than approximately 0.45 μm is defined as the first region. The first region is mainly It is thought that components of SiO, the negative electrode active material, have been detected. The third region is mainly It is thought that components of the film formed by the decomposition of the electrolyte are being detected. The second region is This is considered to be a mixed region of the negative electrode active material and the coating. EDX analysis shown in Figure 49(B) The results show that the strength of carbon in the third region is more than 10 times that of silicon. In contrast, in the second region it is about 1x, and in the first region it is less than 1 / 6. Furthermore, in the EDX analysis results shown in Figure 51(A), the number of carbon atoms in the third region is silico While the number of atoms in the first region is more than 20 times, in the second region it is about 4 times, and in the first region it is about 4 times. In this domain, it is approximately 1x.

[0455] In Figures 50(B) and 51(B), the region from the surface to approximately 0.1 μm is the third region. This region is defined as [region 1]. Additionally, the region from near 0.1 μm to near 0.2 μm is defined as the second region. Furthermore, the region deeper than approximately 0.2 μm is defined as the first region. EDX shown in Figure 50(B) In the analysis results, the strength of carbon in the third region was more than 10 times that of silicon. In region 2, it is approximately 1x, and in region 1, it is less than 1 / 6. See also Figure 51. In the EDX analysis results shown in (B), the number of carbon atoms in the third region is equal to the number of silicon atoms. In contrast to the first domain, the second domain is about 20 times greater, while in the second domain it is about 3 times greater, compared to the first domain. In fact, it's about 1x.

[0456] Next, EELS line analysis was performed as elemental analysis. Line analysis was performed on the storage battery BC. Figure 52(A) shows the SEM image of the area, and Figure 52(B) shows the obtained line analysis spectrum. Figure 53(A) shows the SEM image of the area where line analysis was performed on the storage battery BA, and the obtained line segments. The spectral analysis is shown in Figure 53(B). Here, the vertical axis represents the signal intensity.

[0457] In Figure 52(B), the region from the surface to approximately 0.2 μm is defined as the third region. The region from approximately 0.2 μm to approximately 0.45 μm is defined as the second region. The region deeper than the vicinity of μm is defined as the first region. The EELS analysis results shown in Figure 52(B) Furthermore, the strength of carbon in the third region is more than 10 times that of silicon, In the second region, it is about half, and in the first region, it is less than one-tenth.

[0458] In Figure 53(B), the region from the surface to approximately 0.1 μm is defined as the third region. The region from approximately 0.1 μm to approximately 0.2 μm is defined as the second region. The region deeper than the neighboring region is defined as the first region. In the EELS analysis results shown in Figure 53(B) In the third region, the strength of carbon is more than 10 times that of silicon, and in the first region... That is approximately less than one-tenth.

[0459] From Figures 47 to 53, the negative electrode of battery BA is in the second region compared to the negative electrode of battery BC. The thinness of the material suggests that cracks and micronization of the active material surface are suppressed. [Explanation of symbols]

[0460] 103 Active material 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 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 501i positive electrode current collector 502 Positive electrode active material layer 502i positive electrode active material layer 503 Positive electrode 503i positive electrode 504 Negative electrode current collector 505 Negative electrode active material layer 506 negative electrode 507 Separator 507i Separator 508 Electrolyte 509 Exterior 551 First Domain 552 Second Domain 553 The Third Domain 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 671 Negative electrode active material 681 Cation 681b Precipitated layer 682 Cation 683 Anion 684 Reactants 685 Coating 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 981 film 982 film 990 Battery 991 Exterior 992 Exterior 993 Wound body 994 negative electrode 995 positive electrode 996 Separator 997 Lead Electrode 998 Lead Electrode 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 vent 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 positive electrode, a negative electrode, and an electrolyte. The negative electrode comprises a negative electrode active material which is carbon-coated SiO, and a conductive additive. The negative electrode has a first region, a second region in contact with the surface of the first region, and a third region in contact with the surface of the second region. The electrolyte has 1-ethyl-3-methylimidazolium(fluorosulfonyl)amide, The third region is the region from the surface down to 0.2 μm. The second region is the region from 0.2 μm to 0.45 μm. The first region is a region deeper than 0.45 μm, In line analysis of EELS, In the third region, the strength of carbon is more than 10 times that of silicon. In the second region, the strength of carbon is lower than that of silicon. The first region is a lithium-ion secondary battery in which the strength of carbon is one-tenth or less of the strength of silicon.

2. In claim 1, The negative electrode is a lithium-ion secondary battery in which, in the S2p spectrum of XPS analysis, the spectral intensity near 168 eV is at least twice as strong as the spectral intensity near 163 eV.

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