Electrode and power storage device

Abstract

To provide a novel electrode. To provide a novel electricity storage device. To provide an electrode with little deterioration. To provide an electrode with large capacity. To provide an electricity storage device with a long life. To provide an electricity storage device with little deterioration. To provide an electricity storage device with high energy density. To provide an electricity storage device with high reliability. [Solution] An electrode includes an active material and a graphene compound having a graphene layer and a substituted or unsubstituted chain group, wherein the graphene layer is bonded to the chain group via a silicon-containing substituent. The active material is particulate, the graphene compound has a region in contact with the active material, and the active material includes an element A and an element M, wherein the element A is at least one element selected from Group 1 elements and Group 2 elements, the element M is at least one element selected from manganese and nickel, and the chain group is at least one group selected from a carbonyl group, an ester group, a carboxyl group, an ether group, and an epoxy group.

Description

[Technical field]

[0001] The present invention relates to an article, a method, or a manufacturing method. The present invention relates to a method, manufacture, or composition of matter. One embodiment of the present invention is a power storage device, a storage battery, an electrode, a positive electrode, a semiconductor device, a display device, a light-emitting device, In particular, the present invention relates to a device, a storage device, a driving method thereof, or a manufacturing method thereof. One aspect relates to an electrode and a method for making the same.

[0002] In this specification, the term "electricity storage device" refers to elements and devices in general that have an electricity storage function. That is why. [Background technology]

[0003] In recent years, various types of batteries, such as lithium-ion batteries, lithium-ion capacitors, and air batteries, have become available. The development of high-output, high-energy-density lithium-ion batteries is particularly popular. Ion batteries are used in mobile phones, smartphones, notebook personal computers, and other portable information devices. Electronic devices such as information terminals, portable music players, digital cameras, medical devices, hybrid Hybrid electric vehicle (HEV), electric vehicle (EV), plug-in hybrid vehicle (PHEV), etc. Demand is expanding rapidly with the development of the semiconductor industry, including the next generation of clean energy vehicles. As a source of rechargeable energy, it has become indispensable in today's information society. .

[0004] When a lithium-ion battery is charged and discharged, elements contained in the active material may leach into the electrolyte. This dissolution may result in a decrease in the capacity of the electricity storage device. The dissolution of ions into the electrolyte is described. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-192428 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of one embodiment of the present invention is to provide a novel electrode. An object of one embodiment is to provide a novel power storage device.

[0007] Another object of one embodiment of the present invention is to provide an electrode that is less susceptible to deterioration. An object of one embodiment of the present invention is to provide an electrode having a large capacity. An object of one embodiment of the present invention is to provide a power storage device with a long lifetime. An object of one embodiment of the present invention is to provide a power storage device that is less susceptible to deterioration. An object of one embodiment is to provide a power storage device with high energy density. An object of one embodiment of the present invention is to provide a highly reliable power storage device.

[0008] The description of these problems does not preclude the existence of other problems. It is not necessary for one embodiment to solve all of these problems. The subject matter will be self-evident from the description, drawings, claims, etc. Other issues can be extracted from the drawings, claims, etc. [Means for solving the problem]

[0009] One embodiment of the present invention includes an active material and a graphene compound. The graphene layer has a substituted or unsubstituted chain group, and the graphene layer has silicon. The graphene compound is bonded to a chain-like group via a substituent, and the active material is in the form of particles. The active material has an area contacting the active material, and the active material has an element A and an element M, and the element A is a group 1 element and one or more elements of Group 2, and element M is manganese and nickel The chain group has one or more selected from the group consisting of a carbonyl group, an ester group, a carboxyl group, The electrode has one or more groups selected from an ether group and an epoxy group.

[0010] Alternatively, one embodiment of the present invention includes an active material and a graphene compound, The graphene compound has a region in contact with a surface of the active material, and the active material is , and element M, and element A is at least one selected from the group 1 elements and the group 2 elements. The element M is at least one selected from manganese and nickel, is an electrode having a structure represented by the following formula (G1).

[0011] [ka] (In the general formula (G1), G layer represents a graphene layer, R 1 Is replaced or absent represents a substituted alkylene group, R 2 represents hydrogen or a substituted or unsubstituted alkyl group. )

[0012] Alternatively, one embodiment of the present invention includes an active material and a graphene compound, The graphene compound has a region in contact with a surface of the active material, and the active material is , and element M, and element A is at least one selected from the group 1 elements and the group 2 elements. The element M is at least one selected from manganese and nickel, is an electrode having a structure represented by the following formula (G2).

[0013] [ka] (In the general formula (G2), G layer represents a graphene layer, R 1 Is replaced or absent represents a substituted alkylene group, R 2 represents hydrogen or a substituted or unsubstituted alkyl group. )

[0014] Alternatively, one embodiment of the present invention includes an active material and a graphene compound, The graphene compound has a region in contact with a surface of the active material, and the active material is , and element M, and element A is at least one selected from the group 1 elements and the group 2 elements. The element M is at least one selected from manganese and nickel, is an electrode having a structure represented by the following formula (G3).

[0015] [ka] (In the general formula (G3), G layer represents a graphene layer, R 3 At least It represents a substituted or unsubstituted chain group having two or more ether bonds.

[0016] In the above embodiment, the graphene compound has a function of trapping the element M. is preferred.

[0017] Alternatively, one aspect of the present invention is a battery comprising the electrode according to any one of the above, an outer casing, and an electrolyte solution The power storage device includes a separator and a negative electrode. Effect of the Invention

[0018] According to one embodiment of the present invention, a novel electrode can be provided. Thus, a novel power storage device can be provided.

[0019] According to one embodiment of the present invention, an electrode that is less susceptible to deterioration can be provided. According to one embodiment of the present invention, an electrode having a large capacity can be provided. In addition, according to one embodiment of the present invention, a power storage device having a long lifetime can be provided. In addition, according to one embodiment of the present invention, a power storage device with low energy density can be provided. In addition, according to one embodiment of the present invention, a highly reliable power storage device can be provided. It is possible to provide a power storage device.

[0020] The description of these effects does not preclude the existence of other effects. An embodiment does not necessarily have to have all of these effects. The above will become apparent from the description in the specification, drawings, claims, etc. It is possible to extract other effects from the descriptions in the claims, etc. [Brief description of the drawings]

[0021] [Figure 1] 1A and 1B are a cross-section of an electrode according to one embodiment of the present invention and a partial region of the cross-section of the electrode; [Diagram 2] FIG. 2 is a diagram illustrating a partial cross-sectional area of ​​an electrode according to one embodiment of the present invention. [Diagram 3] 5A to 5C are diagrams illustrating the operation of a power storage device. [Figure 4] 5A to 5C are diagrams illustrating the operation of a power storage device. [Diagram 5] FIG. [Figure 6] FIG. 4 is a diagram illustrating a part of a cross section of an electrode. [Figure 7] FIG. [Figure 8] FIG. 1 is a cross-sectional view of a storage battery. [Figure 9] 1A to 1C are diagrams illustrating a method for manufacturing a storage battery. [Figure 10] 1A to 1C are diagrams illustrating a method for manufacturing a storage battery. [Figure 11] FIG. [Figure 12] FIG. 4 is a diagram for explaining the radius of curvature of a surface. [Figure 13] FIG. 2 is a diagram for explaining the radius of curvature of a film. [Figure 14] FIG. 1 is a diagram illustrating a coin-type storage battery. [Figure 15] FIG. 1 is a diagram illustrating a cylindrical storage battery. [Figure 16] FIG. 2 is a cross-sectional view illustrating a portion of a storage battery. [Figure 17] FIG. 2 is a cross-sectional view illustrating a portion of a storage battery. [Figure 18] FIG. 2 is a cross-sectional view illustrating a portion of a storage battery. [Figure 19] FIG. 1 shows an example of a storage battery. [Figure 20] FIG. 1 shows an example of a storage battery. [Figure 21] 1A and 1B are diagrams for explaining examples of power storage systems. [Figure 22] 1A and 1B are diagrams for explaining examples of power storage systems. [Figure 23] 1A and 1B are diagrams for explaining examples of power storage systems. [Figure 24] 1A to 1C are diagrams illustrating examples of electronic devices. [Diagram 25] 1A to 1C are diagrams illustrating examples of electronic devices. [Figure 26] 1A to 1C are diagrams illustrating examples of electronic devices. [Figure 27] 1A to 1C are diagrams illustrating examples of electronic devices. [Figure 28] FIG. 4 is a diagram showing cycle characteristics of a storage battery. [Figure 29] FIG. 4 is a diagram showing cycle characteristics of a storage battery. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The present invention will be described in detail below with reference to the accompanying drawings. The present invention is not limited to these descriptions, and various modifications in form and details are possible by those skilled in the art. Therefore, the present invention should not be construed as being limited to the description of the following embodiments. It is not something that is done.

[0023] In each figure described in this specification, the size and other details of each element such as a film, layer, substrate, region, etc. The thicknesses and the like may be exaggerated for clarity of explanation. The components are not limited by their size, nor are they limited by the relative size between each other. stomach.

[0024] In this specification, ordinal numbers such as 1st, 2nd, etc. are used for convenience. It does not indicate the order of processes or the order of layers. "The" can be appropriately replaced with "the second" or "the third" etc. Ordinal numbers described in the specification and the like and ordinal numbers used to specify one aspect of the present invention may not match.

[0025] In the configuration of the present invention described in this specification, etc., The same reference numerals are used for the same parts in different drawings, and the repeated explanations are omitted. In addition, when referring to parts having similar functions, the same hatch pattern is used and special symbols are attached. This may not be the case.

[0026] In this specification, both the positive and negative electrodes for a power storage device are collectively referred to as electrodes. In this case, the electrode refers to at least one of the positive electrode and the negative electrode. do.

[0027] Here, the charging and discharging rates of the storage device will be described. For example, When charging a secondary battery (Ah) at a constant current, a charge rate of 1C means that charging will finish in exactly one hour. The current value I [A] at which the charge ends is 0.2C, and a charge rate of 0.2C is I / 5 [A] (i.e. (That is, the current value at which charging is completed in exactly 5 hours.) Similarly, a discharge rate of 1C is is the current value I [A] at which the discharge ends in exactly one hour, and the discharge rate is 0.2C. This is I / 5[A] (i.e., the current value at which the discharge ends in exactly 5 hours). .

[0028] (Embodiment 1) A power storage device of one embodiment of the present invention includes a layer including a graphene compound, a positive electrode, and a negative electrode. The positive electrode and the negative electrode each have an active material. By providing the layer in the device, for example, metals released from the active material can be captured in the layer. The layer can be provided in the vicinity of the active material, for example, so that a part of the layer is in contact with the active material. It is preferable that

[0029] <Structure example> FIG. 1A illustrates an example of a cross-section of an electrode according to one embodiment of the present invention. 2 and a layer 213 on the active material layer 212.

[0030] The active material layer 212 contains an active material 221. The active material 221 contains an element M. The element M is ma. Zn, Nickel, Cobalt, Chromium, Aluminum, Iron, Molybdenum, Zinc, Indium One or more selected from the group consisting of aluminum, gallium, copper, titanium, niobium, and vanadium, in particular manganese or Nickel is preferred.

[0031] In addition to the element M, the active material 221 also contains the element A that functions as a carrier ion. The element A is preferably one or more selected from the group 1 elements and the group 2 elements. The first group element is, for example, an alkali metal such as lithium, sodium, or potassium. In addition, the second group elements, for example, calcium, beryllium, magnesium, etc. can be used.

[0032] The active material 221 may be either a positive electrode active material or a negative electrode active material.

[0033] The layer 213 includes a graphene compound. The graphene compound may be substituted or unsubstituted for the graphene layer. or an unsubstituted chain group, and the graphene layer has, for example, a silicon-containing substituent. It is bonded to the chain group via a

[0034] Here, the graphene compound has, for example, a highly polar functional group as a chain group. This may improve the function of the graphene compound to trap the cations 252. Examples of the aryl group include a carbonyl group, an ester group, a carboxyl group, an ether group, and an epoxy group. and the like, and is preferably an ester group or a carboxy group. is more preferable.

[0035] Here, when the graphene compound has low electronic conductivity, it functions as a separator. Since the graphene compound has a chain-like group, when it comes into contact with the negative electrode, Reduction at potential may be suppressed.

[0036] Also, the layer 213 is, for example, a graphene compound sheet.

[0037] The longitudinal direction of the graphene and multi-graphene that constitute the graphene compound, or The length of the major axis on the surface is 50 nm to 100 μm, or 800 nm to 50 μm Graphene compounds, graphene compound sheets, graphene and multigraphene The details of the graphene will be described later. Also, graphene and multi-graphene are small. There are cases where this is preferable.

[0038] The electrode 210 may also have a current collector 211, and the active material layer 212 may be disposed on the current collector 211. It is preferable that the above-mentioned

[0039] The layer 213 is provided on the active material layer 212. The layer 213 is an active material of the active material layer 212. It has an area bordering on the substance 221.

[0040] FIG. 1B is an enlarged view of the region 230 shown in FIG. 1A. In the example shown in FIG. A plurality of particles of the active material 221 contact the layer 213. The layer 213 contacts the active material 221. In other words, it has a plurality of regions.

[0041] In FIG. 1B, layer 213 is depicted as a continuous layer or sheet. As shown in FIG. 1(C), the layer 213 may be composed of multiple sheets. 3 may penetrate into the inside of the active material layer 212 .

[0042] FIG. 2 shows an example of multiple overlapping sheets as layer 213. The overlapping sheets are partially in contact with each other. It is preferable to do so.

[0043] <Operation of the power storage device> Next, the operation of the power storage device of one embodiment of the present invention will be described with reference to FIGS. Here, the electrode 210 functions as a positive electrode, and the active material 221 is a positive electrode active material. explain.

[0044] The power storage device of one embodiment of the present invention includes an electrode 210 functioning as a positive electrode and an electrode 211 functioning as a negative electrode. The ions of element A are cations 251 and the ions of element M are cations 2 The number is 52.

[0045] First, charging will be described with reference to FIG. Element A is cationized from substance 221, releasing cation 251 and electron 253. The ions 251 reach the negative electrode 220 and are reduced. In this case, the active material 221 is not shown.

[0046] During charging, cations 252 may be released from the active material 221. The release of cation 252 is sometimes referred to as the dissolution of element M. If the cation 252 does not react easily with the negative electrode active material, the reduction In some cases, element M may form a precipitate 254 as a result of the reaction. Alternatively, element M may form a precipitate 254 as a result of the reaction with cation 252 and negative If the reaction with the electrode active material is not reversible, element M may be difficult to ionize during discharge. be.

[0047] If the reaction potential of the negative electrode is lower than the potential at which the electrolyte decomposes, This type of film is formed by an irreversible reaction and may result in a decrease in capacity. When a precipitate 254 of element M is formed on the surface of the electrode 220 during charging, the precipitate A film may tend to build up on the deposits 254, causing a more pronounced loss of capacitance.

[0048] In addition, when the cation 252 is released from the active material 221 during charging (i.e., when the element M is If the active material 221 is dissolved, the crystal structure of the active material 221 may change and become unstable.

[0049] Next, the discharge will be described with reference to FIG. Thione 251 is released and reaches electrode 210 where it is reduced.

[0050] On the other hand, the ionic radius of the cation 252 is larger than the ionic radius of the cation 251 . Furthermore, the release of the cations 252 may cause a change in the crystal structure of the active material 221. In addition, the cations 252 that are desorbed from the active material 221 during charging are re-adsorbed into the active material 221 during discharging. It's difficult to get into 221.

[0051] FIG. 4 shows an example of an electrode 210 having a layer 213. The layer 213 may be, for example, a cation 252 It has the function of trapping.

[0052] When element M is cationized during charging, cation 252 and electron 253 are generated. Since the layer 213 has a function of trapping the cations 252, the electrode 2 On the other hand, cations 251 can diffuse through layer 213 to reach the electrode 20. It is preferable to reach 220.

[0053] When cation 252 is present in the electrolyte and its concentration reaches equilibrium, the dissolution of element M occurs. (cationization) is suppressed. The cations 252 are captured in the layer 213, and the active In the porous layer 212, the concentration of cations 252 is high near the interface with the layer 213. The high concentration of cations 252 suppresses the release of cations 252 from the surface of the active material layer 212. That is, by providing the layer 213, it is possible to suppress the elution of the element M. can.

[0054] In addition, the graphene compound of one embodiment of the present invention has electrical conductivity due to the chain group. By providing the layer 213, the amount of element A on the surface of the electrode 220 may be reduced. Even when the active material 221 of the electrode 210 is precipitated, the active material 221 and the current collector 211 are not precipitated. This is preferable since short-circuiting with the element A deposited on the surface of the electrode 220 may be suppressed.

[0055] After charging, for example, layer 213 contains element M.

[0056] <How to make electrodes> A method for manufacturing an electrode according to one embodiment of the present invention will be described.

[0057] The electrode 210 includes an active material and a graphene compound. It is preferable that the positive electrode active material be included as a material.

[0058] First, the active material layer 212 is prepared. The active material layer 212 has an active material. 12 preferably contains a binder and a conductive assistant. The binder and the conductive assistant are as follows: This will be explained in the embodiment described later.

[0059] The active material, other components, for example, a binder and a conductive additive, and a solvent are mixed. The solvent used to prepare the slurry is preferably a polar solvent. For example, water, methanol, ethanol, acetone, tetrahydrofuran (THF) , dimethylformamide (DMF), N-methylpyrrolidone (NMP) and dimethylsulfate Any one or a mixture of two or more of these compounds can be used.

[0060] Next, the slurry is applied onto a current collector. The current collector will be described in the following embodiment. .

[0061] Next, a heat treatment is performed to volatilize the solvent from the slurry applied to the current collector. A test may also be performed.

[0062] Through the above steps, the active material layer 212 is formed on the current collector.

[0063] Next, the layer 213 is prepared. First, a graphene compound is dispersed in a solvent. Examples of suitable solvents include water, methanol, ethanol, acetone, tetrahydrofuran (THF), dichloromethane, and ethanol. Methylformamide (DMF), 1-methyl-2-pyrrolidone (NMP) and dimethyl Sulfoxide (DMSO), ethylene glycol, diethylene glycol, glycerin, Any one or a mixture of two or more of the above can be used.

[0064] Next, the prepared dispersion liquid is dropped onto the active material layer 212. Alternatively, the active material layer 212 is It may also be impregnated in a dispersion liquid.

[0065] Next, a heat treatment is performed to volatilize the solvent from the dispersion liquid. The treatment is performed in a reduced pressure atmosphere. This makes the solvent more likely to volatilize.

[0066] Through the above steps, the layer 213 is formed on the active material layer 212. The amount of the phenanthrene compound supported is, for example, 0.2 mg / cm 2 More than 10mg / cm 2 The following, or For example, 0.5 mg / cm 2 More than 3mg / cm 2 The following is the result.

[0067] <Cathode active material> As an example of the active material 221, a positive electrode active material containing an element M will be described.

[0068] The positive electrode active material is a material with a spinel-type crystal structure represented by the general formula LiM2O4. Here, the element M is preferably a metal, for example manganese. The element M may be two or more metals selected from a plurality of metals. For example, The metal may be one or more selected from manganese and metals other than manganese. Examples of metals include nickel, cobalt, aluminum, iron, and vanadium. For example, by having nickel as a metal other than manganese in element M, the discharge voltage can be improved. This is preferable because it can improve the energy density. A small amount of lithium nickel oxide is added to a lithium-containing material having a spinel-type crystal structure such as 2O4. (LiNiO2 and Li x Ni (1-x) XO2) may be mixed. Here, element X is For example, cobalt, aluminum, etc. can be used.

[0069] As the positive electrode active material, for example, a layered rock salt type crystal structure or a spinel type crystal structure is used. In addition, a composite oxide having a high conductivity can be used as the positive electrode active material. The following positive electrode materials can be used. As a polyanion-based positive electrode material, for example, olivine type Examples of such materials include materials having a crystal structure of the formula (I) and Nasicon-type materials.

[0070] Various composite oxides can be used as the positive electrode active material. For example, LiFeO2, LiCoO2, LiNiO2, LiMn2O4, V2O5, Cr2O5, MnO2, etc. A mixture of these can be used.

[0071] As an example of a material with a layered rock salt type crystal structure, the composite oxide represented by LiMO2 is The element M is at least one selected from cobalt and nickel. LiCoO2 is preferred because it has a large capacity, is stable in air, and is thermally stable. In addition, the element M is preferably cobalt or nickel. In addition to one or more selected from the group consisting of aluminum and manganese, For example, LiCo x Mn y Ni z O w (x, y, z and w are, for example, x =y=z=1 / 3 or nearby, w=2 or nearby) can be used.

[0072] The neighborhood is, for example, a value greater than 0.9 times and less than 1.1 times the value.

[0073] In addition, a solid solution of a combination of multiple composite oxides can be used as the positive electrode active material. For example, LiCo 1 / 3 Mn 1 / 3 Ni 1 / 3 A solid solution of O2 and Li2MnO3 It can be used as a positive electrode active material.

[0074] An example of a material having a spinel-type crystal structure is the composite oxide represented by LiM2O4. It is preferable to have manganese as element M. For example, LiM n2O4 can be used. In addition to manganese, nickel is also included as the element M. This may improve the discharge voltage of the secondary battery and improve the energy density, which is preferable. In addition, lithium ions having a spinel crystal structure containing manganese, such as LiMn2O4, The material contains a small amount of lithium nickel oxide (LiNiO2 or LiNi 1-x M x O2(M= By mixing Co, Al, etc., the characteristics of the secondary battery can be improved, which is preferable. stomach.

[0075] For example, the average particle size of the primary particles of the positive electrode active material is 5 nm or more and 100 μm or less. Preferably, the thickness is 50 nm or more and 50 μm or less, more preferably, 100 nm or more and 50 It is more preferable that the specific surface area is 5m 2 / g or more 15m 2 / g or less It is preferable that the average particle size of the secondary particles is 5 μm or more and 50 μm or less. The average particle size is preferably measured by observation using a SEM (scanning electron microscope) or a TEM. The particle size distribution can be measured by a particle size distribution meter using a laser diffraction / scattering method. The specific surface area can be measured by a gas adsorption method.

[0076] A conductive material such as a carbon layer may be provided on the surface of the positive electrode active material. For example, the positive electrode active material may be provided with carbon. The layer coating is formed by mixing carbohydrates such as glucose during the firing of the positive electrode active material. This can be done.

[0077] For example, a polyanion-based positive electrode material may be prepared by mixing oxygen, element X, metal A, and metal M. The metal M can be iron, manganese, cobalt, etc. Metal A is one or more of lithium, sodium, zinc, nickel, titanium, vanadium, and niobium. element X is one or more of sulfur, phosphorus, molybdenum, tungsten, Arsenic, silicon or more.

[0078] In addition, the composite material (general formula LiMPO4 (where M is Fe(II), Mn(II), Co(I) Representative examples of the general formula LiMPO4 include: Examples include LiFePO4, LiNiPO4, LiCoPO4, LiMnPO4, and LiFe a Ni b PO4, LiFe a Co b PO4, LiFe a Mn b PO4, LiNi a Co b PO4, LiNi a Mn b PO4(a+b is less than 1, 0 <a<1、0<b<1)、LiF e c Ni d Co e PO4, LiFe c Ni d Mn e PO4, LiNi c Co d Mn e PO 4(c+d+e is less than 1, 0 <c<1、0<d<1、0<e<1)、LiFe f Ni g C o h Mn i PO4(f+g+h+i is less than 1, 0 <f<1、0<g<1、0<h<1、0 Lithium compounds such as <i<1) can be used.

[0079] In particular, LiFePO4 satisfies well the requirements for the cathode active material, such as safety, stability, high capacity density, and the presence of lithium ions that can be extracted during initial oxidation (charging). Therefore, it is preferable.

[0080] Also, composite materials such as the general formula Li (2-j) MSiO4 (M is one or more of Fe(II), Mn(II), Co( II), Ni(II), 0 ≦ j ≦ 2) can be used. Generally Formula Li (2-j) Typical examples of MSiO4 include Li (2-j) FeSiO4, Li (2 -j) NiSiO4, Li (2-j) CoSiO4, Li (2-j) MnSiO4, Li (2-j) Fe k Ni l SiO4, Li (2-j) Fe k Co l SiO4, Li (2-j ) Fe k Mn l SiO4, Li (2-j) Ni k Co l SiO4, Li (2-j) Ni k Mn l SiO4 (k + l is 1 or less, 0 < k < 1, 0 < l < 1), Li (2-j) Fe m N i n Co q SiO4, Li (2-j) Fe m Ni n Mn q SiO4, Li (2-j) Ni m Con Mn q SiO4 (where m + n + q is 1 or less, 0 < m < 1, 0 < n < 1, 0 < q < 1) , Li (2-j) Fe r Ni s Co t Mn u SiO4 (where r + s + t + u is 1 or less, 0 < r < 1, 0 < s < 1, 0 < t < 1, 0 < u < 1), etc. Lithium compounds can be used as materials in this way.

[0081] Also, x A M2(XO4)3 (A = Li, Na, Mg, M = Fe, Mn, Ti, V, N b, X = S, P, Mo, W, As, Si) Nasicon-type compounds represented by the general formula can be used in this way. Examples of Nasicon-type compounds include Fe2(MnO4)3, Fe2(SO4)3 , Li3Fe2(PO4)3, etc. Also, as the positive electrode active material, compounds represented by the general formula Li2MPO4F, L i2MP2O7, Li5MO4 (M = Fe, Mn) can be used in this way.

[0082] Also, polyanion-based positive electrode materials containing V can be used. Representative examples include α- LiVOPO4, β-LiVOPO4, α1-LiVOPO4, LiVPO4F, LiV PO4O, LiVP2O7, LiVOSO4, Li2VOSiO4, LiVMoO6, etc can be mentioned.

[0083] Also, as the positive electrode active material, perovskite-type fluorides such as NaFeF3, FeF3, etc., T iS2, MoS2, etc. metal chalcogenides (sulfides, selenides, tellurides), LiM VO4, etc. oxides having an inverse spinel-type crystal structure, vanadium oxide-based (V2O5, V 6O 13Materials such as manganese oxides and organic sulfur compounds can be used. can.

[0084] In addition, the positive electrode active material is a lithium-ion battery having the general formula LiMBO3 (where M is Fe(II), Mn(II), A borate-based positive electrode material represented by Co(II) can be used.

[0085] In addition, the positive electrode active material is Li a Mn b M c O d Lithium ion can be expressed as In this case, the element M is any element other than lithium or manganese. It is preferable to use a metal element selected from the group consisting of silicon and phosphorus, and nickel is preferably used. It is more preferable to measure the entire particle of the lithium manganese composite oxide. When the voltage is applied <a / (b+c)<2、かつc>, the value is 0.0 and 0.26≦(b+c) / d<0.5. In order to realize high capacity, it is preferable that the crystal structure is The lithium manganese composite oxide has regions with different crystal orientations or oxygen contents. In order to obtain such a lithium manganese composite oxide, it is preferable that, for example, 1.6≦ It is preferable that a≦1.848, 0.19≦c / b≦0.935, and 2.5≦d≦3. In addition, Li 1.68 Mn 0.8062 Ni 0.318 The formula for the compound is O3. It is particularly preferable to use lithium manganese composite oxide. 1. 68 Mn 0.8062 Ni 0.318 Lithium manganese composite with the formula O3 The oxide is the ratio (molar ratio) of the amount of raw materials, Li2CO3:MnCO3:NiO=0​ Lithium manganese oxide composite formed by mixing 0.84:0.8062:0.318 Therefore, the lithium manganese composite oxide has the composition formula Li 1.68 Mn 0.80 62 Ni 0.318 It is represented by O3, but the composition can deviate from this.

[0086] The composition of metals, silicon, phosphorus, etc. of the entire lithium manganese composite oxide particle is, for example, For example, it can be measured using an ICP-MS (inductively coupled plasma mass spectrometer). The oxygen composition of the entire lithium manganese oxide particle was measured using, for example, EDX (energy dispersion It can also be measured using ICP-MS analysis. This can be determined by using valence evaluation from melt gas analysis and XAFS (X-ray absorption fine structure) analysis. The lithium manganese composite oxide is a material that contains at least lithium and manganese. It 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:

[0087] Lithium manganese composite oxide having regions with different crystal structures, crystal orientations or oxygen contents An example of a cross-section of a particle of an object is shown in Figure 5.

[0088] As shown in FIG. 5(A), the crystal structure, crystal orientation, or oxygen content of the region is different. The lithium manganese composite oxide has a region 331, a region 332, and a region 333. Preferably, the region 332 contacts at least a part of the outside of the region 331. The region 333 is closer to the surface of the particle. It is preferred to have a region coincident with the surface of the grain that has a silicide.

[0089] Also, as shown in FIG. 5B, the region 331 has an area that is not covered by the region 332. Also, the region 332 may have an area that is not covered by the region 333. For example, the region 331 may be adjacent to the region 333. 2 and region 333.

[0090] Region 332 preferably has a different composition than region 331 .

[0091] For example, the composition of region 331 and region 332 are measured separately, and region 331 contains lithium and manganese. 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: The atomic ratio of lithium, manganese, element M, and oxygen in region 332 is represented as c1:d1. The case where area 331 and area 332 are expressed as a2:b2:c2:d2 will be described. The composition of each of the 32 can be determined by, for example, EDX (energy dispersive x-ray diffraction) using a TEM (transmission electron microscope). The measurement using EDX can measure the composition of lithium. Therefore, in the following, we will focus on the difference in composition between region 331 and region 332. The following describes elements other than lithium. Here, d1 / (b1+c1) is 2.2 or more. is preferable, more preferably 2.3 or more, and even more preferably 2.35 or more and 3 or less. It is more preferable that d2 / (b2+c2) is less than 2.2. It is more preferable that the ratio is less than 1.1, and further more preferable that the ratio is 1.1 or more and 1.9 or less. Even in this case, the entire lithium manganese composite oxide particle including the regions 331 and 332 The composition preferably satisfies the above-mentioned condition 0.26≦(b+c) / d<0.5.

[0092] In addition, the manganese in region 332 has a different valence than the manganese in region 331. In addition, the element M in the region 332 may have a different valence from the element M in the region 331. The number may be any number.

[0093] More specifically, the region 331 is a lithium manganese composite having a layered rock salt type crystal structure. The region 332 is preferably a lithium oxide having a spinel type crystal structure. It is preferable that the metal oxide is a manganese-manganese composite oxide.

[0094] Here, when there is a spatial distribution in the composition of each region or the valence of an element, for example, The composition and valence of each area are evaluated, and the average value is calculated. good.

[0095] A transition layer may be provided between the region 332 and the region 331. For example, a transition layer is a region where the composition changes continuously or stepwise. A transition layer is a region where the structure changes continuously or stepwise. A region where the constant changes continuously or stepwise. Or, region 332 and region 331 A mixed layer may be provided between the two layers. Here, the mixed layer is, for example, a layer having two layers with different crystal orientations. The mixed layer refers to a mixture of the above crystals. Alternatively, the mixed layer may be a layer of crystals having different crystal structures. Alternatively, a mixed layer may refer to a mixture of two or more crystals having different compositions, e.g. This refers to the case where two or more crystals are mixed together.

[0096] Region 333 can be made of carbon or a metal compound, where the metal is For example, cobalt, aluminum, nickel, iron, manganese, titanium, zinc, lithium, etc. Examples of metal compounds include oxides and fluorides of these metals. can be.

[0097] Of the above, it is particularly preferable that the region 333 contains carbon. Carbon has high electrical conductivity. Therefore, by using carbon-coated particles in the electrodes of a power storage device, the resistance of the electrodes can be reduced, for example. In addition, the region 333 preferably includes a graphene compound. By using a graphene compound in the region 333, the particles of lithium manganese composite oxide The graphene compound will be described later. More specifically, 33 may include graphene or graphene oxide. In addition, graphene obtained by reducing graphene oxide is used as the graphene. Graphene has excellent electrical properties, such as high electrical conductivity, and high flexibility. The region 333 has excellent physical properties, such as high mechanical strength and oxidation. By using laphene to perform reduction, the region 332 adjacent to the region 333 may be oxidized. be.

[0098] The region 333 has a graphene compound, so that the lithium manganese composite oxide can be used as a positive electrode. The cycle characteristics of a secondary battery using this material can be improved.

[0099] The thickness of the carbon-containing layer is preferably 0.4 nm or more and 40 nm or less.

[0100] In addition, the carrier ion may be an alkali metal ion or an alkaline earth ion other than the lithium ion. In the case of metal ions, instead of lithium, an alkali metal (e.g., sodium) is used as the positive electrode active material. thorium, potassium, etc.), alkaline earth metals (e.g. calcium, strontium, barium, etc.), For example, a layered oxide containing sodium may be used. Things can be used.

[0101] Examples of materials containing sodium include NaFeO2 and Na 2 / 3 [Fe 1 / 2 Mn 1 / 2 ]O2, Na 2 / 3 [Ni 1 / 3 Mn 2 / 3 ]O2, Na2Fe2(SO4)3, Na3V2(PO4)3, Na2FePO4F, NaVPO4F, NaMPO4 (M is Fe(II), Mn(II), Co(II), Ni(II)), Na2FePO4F, N A sodium-containing oxide such as a4Co3(PO4)2P2O7 is used as the positive electrode active material. It is possible.

[0102] In addition, lithium-containing metal sulfides can be used as the positive electrode active material. For example, L Examples include i2TiS3 and Li3NbS4.

[0103] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0104] (Embodiment 2) In this embodiment, a graphene compound of one embodiment of the present invention will be described.

[0105] <Graphene compounds> First, graphene and graphene compounds will be described.

[0106] Graphene is a material in which the carbon atoms are sp 2 It is a sheet of one atomic layer bonded by hybrid orbitals, The carbon atoms are arranged in a hexagonal lattice structure on a flat surface. The bonds between the carbon atoms are stronger than those in diamond. It is a material with strong bonding and extremely high resistance to deformation and tension. It is highly conductive and does not allow lithium ions to pass through it well.

[0107] Graphene with one atomic layer of carbon atoms is sometimes called single-layer graphene. A graphene that has 2 to 100 layers is called multi-graphene. Graphene and multi-graphene are, for example, The thickness is 50 nm or more and 100 μm or less, or 800 nm or more and 50 μm or less. In the specification, graphene includes single-layer graphene and multi-graphene.

[0108] However, in general, graphene may have various types of defects. The carbon atoms that form the rings may be missing, and the lattice may contain five- or seven-membered rings in addition to six-membered rings. Also, it may have functional groups that contain carbon or elements other than carbon. By utilizing these defect sites, atoms or atomic groups can be attached to graphene to impart desired properties. It can be expressed.

[0109] In the present specification and the like, a compound having graphene as a basic skeleton is referred to as a graphene compound ( In this specification, the term "single-layer graphene compound" is used. Laphenes and multigraphenes are both included in graphene compounds.

[0110] The graphene compound will be described in detail below.

[0111] Graphene compounds include, for example, graphene having atoms other than carbon or having atoms other than carbon. In addition, graphene is a compound chemically modified with an alkyl group, an alkylene group, etc. The compound may be chemically modified with an atomic group mainly composed of carbon, such as a graphene group. The atomic group that chemically modifies a compound may be called a chemical modifying group, a modifying group, a substituent, a functional group, or a characteristic group. In this specification and the like, chemical modification refers to a substitution reaction, an addition reaction, or other By the reaction of This refers to the introduction of an atomic group into (described below).

[0112] Chemical modification does not only involve the introduction of one type of atom or atomic group, but also involves the introduction of multiple types of chemical modifications. Chemical modification also refers to the introduction of multiple types of atoms or atomic groups. This also includes reactions that add halogen atoms, hydrocarbon groups, aromatic hydrocarbon groups, and heterocyclic groups. In addition, reactions for introducing atomic groups into graphene include addition reactions and substitution reactions. In addition, the Friedel-Crafts reaction, Bingel reaction, A radical addition reaction may be carried out on graphene. Alternatively, a ring may be formed between the graphene and the atomic group by a cycloaddition reaction.

[0113] The front and back surfaces of graphene are chemically modified with different atoms or atomic groups. In multi-graphene, each layer may be composed of different atoms or atomic groups. It may be chemically modified.

[0114] Examples of graphene compounds chemically modified with the above-mentioned atoms or atomic groups include oxygen or Graphene chemically modified with oxygen-containing functional groups is an example. The graphene compound chemically modified with the group was called graphene oxide (GO). In this specification, graphene oxide refers to a multi-layered oxide. The term "graphene oxide" is intended to include graphene oxide.

[0115] An example of graphene oxide is shown in structural formula (300). In structural formula (300), a graphene layer ( G layer) has epoxy groups, hydroxyl groups, and carboxyl groups. The type and number of functional groups contained in the oxidized graphene are not limited thereto.

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[0117] A simplified structure of graphene oxide is shown in general formula (G3). In general formula (G3), G layer stands for graphene layer. Graphene layers are formed by bonding carbon atoms. The graphene layer is a sheet-like layer, and the number of layers may be one or more. Hereinafter, graphene oxide will be described using the general formula (G3). Although the general formula (G3) shows two hydroxyl groups, in the present invention, The type and number of functional groups contained in the layer are not limited to those mentioned above.

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[0119] Next, an example of a method for producing graphene oxide will be described. Alternatively, the graphene oxide can be obtained by oxidizing graphene or multi-graphene. Graphite oxide can be obtained by oxidizing graphite. Here, the above-mentioned atoms or atomic groups can be further chemically modified in the graphene oxide. It can also be decorated.

[0120] The compound obtained by reducing graphene oxide is called RGO (Reduced Graphene Oxide). RGO is sometimes called graphene oxide. Not all of the atoms are eliminated, and some oxygen or atomic groups containing oxygen remain bonded to carbon. There may be cases where this occurs.

[0121] Graphene compounds are composed of multiple graphene compounds that overlap partially to form a single sheet. Such a graphene compound may be called a graphene compound sheet. The graphene compound sheet may have a thickness of, for example, 0.33 nm or more and 10 mm or less. More preferably, the graphene compound has a region larger than 0.34 nm and smaller than 10 μm. A group is a group consisting of an atom other than carbon, an atomic group containing an atom other than carbon, or a group mainly composed of carbon such as an alkyl group. The graphene compound sheet may be chemically modified with an atomic group such as Each of the layers may be chemically modified with a different atom or atomic group. .

[0122] Graphene compounds are composed of not only six-membered rings made of carbon, but also five-membered rings made of carbon and In this case, the vicinity of the seven-membered or more ring may be In this case, there may be an area through which lithium ions can pass.

[0123] For example, graphene compounds are formed by assembling multiple graphene compounds into a sheet-like shape. The shape may be the same as above.

[0124] The graphene compound has a planar shape, which allows for surface contact.

[0125] <Chemically modified graphene compounds> Next, the chemically modified graphene compound will be described.

[0126] The graphene compound according to one embodiment of the present invention may be chemically modified to have a carbonyl group, an ester group, or the like. Contains one or more groups selected from the group consisting of a tertyl group, a carboxyl group, an ether group, an epoxy group, and the like. The graphene compound preferably has a functional group, such as an ester group or a carboxyl group. More preferably, the modifying agent is a graphene compound having an ester group or a carboxyl group. The molecular weight of the modifier increases due to the increase in the number of carboxyl groups, and the graphene compound In the process of synthesizing the above, when chemically modifying graphene or graphene oxide, the modifying agent is Therefore, chemical modification of graphene or graphene oxide may cause the graphene to become difficult to dissolve in the solvent. In addition, if there are too many ester groups, hydrolysis may occur. Therefore, the number of ester groups or carboxyl groups in the modifying agent is preferably 1 to 10. The following is preferred:

[0127] The graphene compound according to one embodiment of the present invention is, for example, polyethylene oxide (PE O), the heat resistance is high. In particular, the internal If damage to the structure causes unexpected reactions, it may develop into a major accident such as a fire or explosion. Therefore, high heat resistance is important.

[0128] The graphene compound according to one embodiment of the present invention may, for example, include a graphene layer and a substituted or unsubstituted chain. and a chain-like group, and the graphene layer is bonded to the chain-like group via a substituent having Si. Here, as shown in the general formula (G1), the substituent having Si is, for example, a substituent having Si and O. The graphene compound of one embodiment of the present invention is, for example, a silico compound represented by General Formula (G1). and oxygen bonded to the silicon, the silicon being a chain having an ester group. The group is bonded to the

[0129] One embodiment of the present invention is a graphene compound represented by the following general formula (G1) or general formula (G2). It is an object.

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[0132] In the general formula (G1) and the general formula (G2), G layer represents a graphene layer. .

[0133] The graphene compound according to one embodiment of the present invention has a structure represented by general formula (G1) and general formula (G2). By doing so, the reduction resistance may be improved compared to GO.

[0134] In the general formula (G1) and the general formula (G2), R 1 is a substituted or unsubstituted alkylene group R 1may be branched. Also, R 2 is hydrogen, or a substituted or unsubstituted alkane. R represents the alkyl group. 2 The general formula (G1) may be a branched one. In general formula (G2), R 2 When is an alkyl group Since the general formula (G2) has an ester group, it is classified as an ester. ) in R 2 When is hydrogen, general formula (G2) has a carboxyl group, so It is classified as a carboxylic acid.

[0135] The substitution in the above general formula (G1) or the above general formula (G2) is preferably methyl. group, ethyl group, n-propyl group, iso-propyl group, sec-butyl group, tert-butyl group an alkyl group having 1 to 6 carbon atoms, such as an n-ethyl group, an n-pentyl group, or an n-hexyl group; , phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 1-naphthyl group, 2-naphthyl group It represents substitution by a substituent such as an aryl group having 6 to 10 carbon atoms, such as an aryl group. It also represents substitution by a substituent such as fluorine or trifluoromethane.

[0136] Also preferably, R 1 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms. Also preferably, R 2 is hydrogen, or a substituted or unsubstituted C1 to C2 0 alkyl group. Compared to graphene or graphene oxide, the chemically modified graphene In some cases, the interlayer distance of the phenyl compound is large. The larger the interlayer distance, the lower the electronic conductivity. R is adjusted so that the interlayer distance provides the desired electronic conductivity. 1 and R 2 If you select appropriately good.

[0137] By reducing the electronic conductivity of the graphene compound, for example, the electrode 210 can be In some cases, the electric field on the surface of the electrode 210 may be reduced by having

[0138] Also preferably, R 1 is a substituted or unsubstituted alkylene group having 1 to 11 carbon atoms. Also preferably, R 2 is a substituted or unsubstituted alkyl group having 1 to 11 carbon atoms; For example, from the viewpoint of dispersibility in a solvent, this number of carbon atoms is preferable.

[0139] The graphene of the graphene compound according to one embodiment of the present invention has a molecular weight or structure that is unique. The present invention is not limited to the above-mentioned size, and graphene of any size can be used. It is difficult to specify in detail the molecular structure of the graphene compound according to one embodiment and to fully express it. Therefore, the chemically modified graphene compound according to one embodiment of the present invention is Substituted or unsubstituted groups containing at least one ester group, or carboxyl group A graphene compound chemically modified with a silicon compound having a substituted or unsubstituted group; In some cases, it may be more practical to specify the product by expressing its manufacturing process, etc. In addition, the graphene layer and the silicon may be In some cases, the compound is fixed to the graphene layer by two Si-O bonds as shown in the above formula, but It may be fixed by one or three Si-O bonds. The immobilization is not limited to the above bond, and may be performed by other bonds. Silicon that is not bonded to the laphene layer has hydroxyl or alkoxy groups bonded to it. There are cases like this.

[0140] Alternatively, the chemically modified graphene compound according to one embodiment of the present invention is represented by the following general formula (G3 ) is a graphene compound represented by the formula:

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[0142] In the general formula (G3), G layer represents a graphene layer. ) in R 3 is a substituted or unsubstituted linear alkyl group having at least two ether bonds. represents a group, R 3 The G layer and Si can be branched. In some cases, the Si-O bond is fixed to the G layer. In some cases, the bond is fixed by one or three of these. Also, the bond is not limited to Si-O bonds. The immobilization may be achieved by other bonds, not just by bonding with the antibody.

[0143] The graphene compound according to one embodiment of the present invention has a structure represented by general formula (G3), and thus, In some cases, the reduction resistance is improved compared to

[0144] <Chemical modification> Next, the graphene or graphene oxide is chemically modified to obtain a chemically modified graphene. The method for producing the compound is shown in the following synthesis scheme (A-1) and synthesis scheme (A-2). This will be explained using:

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[0147] In the synthetic schemes (A-1) and (A-2), the G layer is a gra Represents the fen layer.

[0148] As shown in the synthesis scheme (A-1) and the synthesis scheme (A-2), graphene or an acid The oxidized graphene is treated with one or more ester or carboxyl groups in the presence of a Lewis base. By reacting a silicon compound containing the compound, a chemically modified target compound can be obtained. This type of reaction is sometimes called silylation.

[0149] Silylation refers to the reaction of a hydroxyl group, an amino group, a carboxyl group, an amide group, or a mercapto group with a silyl group. This indicates that the hydrogen atoms of groups, etc. are replaced with silicon atoms. The compound may be referred to as a silylating agent.

[0150] As the Lewis base, an alkylamine or a heterocyclic aromatic compound may be used. These include butylamine, pentylamine, hexylamine, diethylamine, dipropylamine, amine, dibutylamine, triethylamine, tripropylamine, pyridine One or more may be used.

[0151] Also, the reaction may be carried out in an atmosphere of a gas inert to the reaction, for example, nitrogen or a rare gas such as argon. It is preferable to carry out the reaction under nitrogen or argon atmosphere. The reaction atmosphere is preferably nitrogen or The gas is not limited to argon, but may be, for example, air.

[0152] In the synthetic scheme (A-1) and the synthetic scheme (A-2), R 1 is substituted or unsubstituted R represents an alkylene group. 1 may be branched. R 2 is hydrogen, or a substituted or unsubstituted R represents a substituted alkyl group; 2 may be branched.

[0153] Also preferably, R 1 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms. Also preferably, R 2 is hydrogen, or a substituted or unsubstituted C1 to C2 0 alkyl group.

[0154] Also preferably, R 1 is a substituted or unsubstituted alkylene group having 1 to 11 carbon atoms. Also preferably, R 2 is a substituted or unsubstituted alkyl group having 1 to 11 carbon atoms; It is.

[0155] In the synthetic scheme (A-1) and the synthetic scheme (A-2), usable As the isobase, butylamine, pentylamine, hexylamine, diethylamine, Dipropylamine, dibutylamine, triethylamine, tripropylamine, pyridine However, the Lewis bases that can be used are not limited to these. It is not something that can be done.

[0156] Solvents that can be used in the synthesis schemes (A-1) and (A-2) The solvents are aromatic hydrocarbons such as toluene, xylene, and mesitylene, as well as hexane, hepta, and the like. Examples of such ethers include hydrocarbons such as ethylene glycol dimethyl ether and the like. However, the solvents that can be used are not limited to these. In particular, Lewis salts A more preferred combination is a primary amine group and an aromatic hydrocarbon solvent.

[0157] In addition to the silicon compounds shown in the synthetic schemes (A-1) and (A-2), Those having an alkoxysilyl group may also be used. However, they are not limited to these. do not have.

[0158] <Example> Next, examples of chain silicon compounds having one or more ester groups or carboxyl groups are given below. The silicon compounds are shown below. By using these silicon compounds, one or more ester groups or carboxyl groups can be formed. It was possible to prepare a graphene compound chemically modified with a chain-like group having a carboxyl group. Compounds 100 to 149 and compounds 156 to 161 are Compounds 150 to 155 are classified as esters because they have an ester group. It has an aryl group and is classified as a carboxylic acid.

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[0164] By using the silicon compound as described above, at least one ester group or It is possible to produce a graphene compound having a chain-like group containing a carboxyl group. The graphene compound according to one embodiment of the present invention is prepared using the silicon compound described above. The present invention is not limited to the above.

[0165] Next, examples of silylating agents containing a chain group having two or more ether bonds are described below. By using these silylating agents, chemical modification can be achieved by the chain-like group having an ether bond. It is possible to prepare a graphene compound having a decorated structure.

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[0172] Note that one embodiment of the present invention has been described in this embodiment. In the following, one embodiment of the present invention will be described. However, the embodiment of the present invention is not limited to these. For example, in one embodiment of the present invention, at least one ester group or carboxyl group is Although an example of a graphene compound having a chain group including a xyl group has been described, one embodiment of the present invention is This is not limited to the above.

[0173] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0174] (Embodiment 3) In this embodiment, an active material, a binder, a conductive material, and a conductive material that are preferably contained in the electrode of one embodiment of the present invention will be described. The electric auxiliary and the current collector will now be described.

[0175] The electrode of one embodiment of the present invention includes an active material. The positive electrode of one embodiment of the present invention may include a conductive assistant.

[0176] When the electrode of one embodiment of the present invention is a positive electrode, the electrode contains a positive electrode active material as an active material. As for the active material, it is preferable to use the positive electrode active material described in the above embodiment.

[0177] For example, when the electrode 210 described in the previous embodiment is a positive electrode, the electrode 220 is a negative electrode. It is preferable that

[0178] When the electrode of one embodiment of the present invention is a negative electrode, the electrode contains a negative electrode active material as an active material.

[0179] <Negative electrode active material> As the negative electrode active material of the electrode, for example, a carbon-based material or an alloy-based material can be used. do.

[0180] Carbon-based materials include graphite, graphitizable carbon (soft carbon), and non-graphitizable carbon (hard carbon). Carbon nanotubes, graphene, carbon black, etc. stomach.

[0181] Examples of graphite include artificial graphite and natural graphite. Examples of artificial graphite include meso graphite. Examples include carbon microbeads (MCMB), coke-based artificial graphite, and pitch-based artificial graphite. Here, as the artificial graphite, spherical graphite having a spherical shape can be used. For example, the MCMB may have a spherical shape, which is preferred. It is relatively easy to reduce the product, which may be preferable. , flake graphite, and spherical natural graphite.

[0182] Graphite is formed when lithium ions are inserted into graphite (lithium-graphite intercalation compound is formed) It shows a low potential similar to that of lithium metal (0.05 to 0.3 V vs. Li / L i + This allows the lithium-ion secondary battery to exhibit a high operating voltage. In addition, graphite has a relatively high capacitance per unit volume, a relatively small volume expansion, and is inexpensive. However, lithium ions are preferred because they have the advantage of being safer than metallic lithium.

[0183] When lithium ions are inserted into graphite, for example, the interlayer distance of the graphite is 0. It is known that the interlayer distance increases from 3354 nm to 0.370 nm. Increased by 11%.

[0184] As a negative electrode active material, it can carry out charge and discharge reactions by alloying and dealloying reactions with lithium. Any possible element can be used, for example silicon, tin, gallium, aluminum, Germanium, lead, antimony, bismuth, silver, zinc, cadmium, indium, etc. Materials containing at least one of these elements can be used. These elements have a low capacity compared to carbon. Silicon has a high theoretical capacity of 4200mAh / g. It is preferable to use silicon, and compounds containing these elements may also be used. For example, SiO, Mg2Si, Mg2Ge, SnO, SnO2, Mg2Sn, SnS2, V2Sn3, FeSn2, CoSn2, Ni3Sn2, Cu6Sn5, Ag3Sn, Ag 3Sb, Ni2MnSb, CeSb3, LaSn3, La3Co2Sn7, CoSb3, InSb, SbSn, etc. Here, charging and discharging are performed by alloying and dealloying reactions with lithium. Elements capable of undergoing a reaction and compounds containing such elements are sometimes called alloy materials. be.

[0185] In this specification and the like, SiO refers to, for example, silicon monoxide. Alternatively, SiO refers to, It can also be expressed as SiOx, where x preferably has a value close to 1. For example, x is preferably 0.2 or more and 1.5 or less, and more preferably 0.3 or more and 1.2 or less.

[0186] In addition, the negative electrode active material of one embodiment of the present invention may contain silicon, lithium, and oxygen. For example, silicon and lithium silicon oxide positioned outside the silicon may be It may have.

[0187] In addition, titanium dioxide (TiO2) and lithium titanium oxide (Li4 Ti5O 12 ), lithium-graphite intercalation compound (Li x C6), niobium pentoxide (Nb2O5 ), tungsten oxide (WO2), molybdenum oxide (MoO2), etc. can be done.

[0188] In addition, the negative electrode active material is a composite nitride of lithium and transition metals, which has a Li3N structure. Li (3-x) M x N (M=Co, Ni, Cu) can be used. For example, Li 2.6 Co 0.4 N3 has a large charge / discharge capacity (900mAh / g, 1890mAh / cm 3 ) and is preferred.

[0189] When a composite nitride of lithium and transition metals is used, the negative electrode active material contains lithium ions, In addition, materials that do not contain lithium ions, such as V2O5 and Cr3O8, are used as the positive electrode active material. In addition, when a material containing lithium ions is used as the positive electrode active material, However, by first removing the lithium ions contained in the positive electrode active material, As the lithium-transition metal nitride, a complex nitride of lithium and a transition metal can be used.

[0190] In addition, a material that undergoes a conversion reaction can be used as the negative electrode active material. For example, lithium oxide such as cobalt oxide (CoO), nickel oxide (NiO), and iron oxide (FeO) A transition metal oxide that does not form an alloy with the metal may be used as the negative electrode active material. Further materials that cause this include Fe2O3, CuO, Cu2O, RuO2, and Cr2O3. Oxides such as CoS 0.89 , NiS, CuS and other sulfides, Zn3N2, Cu3N, Ge Nitrides such as 3N4, phosphides such as NiP2, FeP2, CoP3, FeF3, BiF3, etc. This also occurs with fluoride.

[0191] The negative electrode active material is preferably such that the lower the reaction potential is, the higher the voltage of the power storage device can be increased. On the other hand, when the potential is low, the power to reduce the electrolyte is also strong. The range of potentials within which the electrolyte does not decompose is called the potential window. The negative electrode is essentially a potential window where the electrode potential is equal to that of the electrolyte. It is preferable that the potential is within the potential window. For example, in a lithium ion secondary battery or a lithium ion capacitor, Many of the active materials used in the negative electrode of a capacitor have potentials that exceed the potential window of almost all electrolytes. In particular, materials with low reaction potential such as graphite and silicon can increase the voltage of the storage device. While there are advantages, there is a problem in that the electrolyte is more susceptible to reductive decomposition.

[0192] <Binding agent> The binders in the electrodes are styrene-butadiene rubber (SBR) and styrene-isopropanol. Acrylonitrile-Butadiene Rubber, Ethylene-Styrene Rubber, Acrylonitrile-Butadiene Rubber, Butadiene Rubber, Ethylene- It is preferable to use a diene rubber material such as a propylene-diene copolymer. As the adhesive, fluororubber can be used.

[0193] As the binder, it is preferable to use, for example, a water-soluble polymer. As the molecule, for example, polysaccharides can be used. CMC, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose Cellulose derivatives such as cellulose, diacetyl cellulose, regenerated cellulose, and starch These water-soluble polymers can be used in combination with the above-mentioned rubber materials. It is even better if there is a

[0194] Alternatively, the binder may be polystyrene, polymethyl acrylate, or polymethyl methacrylate. Polyvinyl chloride (Polymethyl methacrylate (PMMA)), Sodium polyacrylate, Polyvinyl chloride Polyvinyl alcohol (PVA), polyethylene oxide (PEO), polypropylene oxide, Polyimide, polyvinyl chloride, polytetrafluoroethylene, polyethylene, polypropylene Polyethylene, polyisobutylene, polyethylene terephthalate, nylon, polyvinylidene fluoride Polyvinyl chloride (PVdF), polyacrylonitrile (PAN), ethylene propylene diene polymer It is preferable to use materials such as polyvinyl acetate and nitrocellulose.

[0195] Two or more of the above binders may be used in combination.

[0196] The content of the binder relative to the total amount of the active material layer 102 is preferably 1 wt % or more and 10 wt % or less. Preferably, the content is 2 wt% or more and 8 wt% or less, more preferably, 3 wt% or more and 5 wt% or less. The content of the conductive assistant with respect to the total amount of the active material layer 102 is preferably 1 wt % or more and 10 wt % or less. t% or less is preferable, and 1 wt% or more and 5 wt% or less is more preferable.

[0197] <Conductive assistant>

[0198] The conductive assistant of the electrode may be, for example, a carbon material, a metal material, or a conductive ceramic material. In addition, a fibrous material may be used as the conductive assistant. The content of the conductive assistant with respect to the total amount of the layer is preferably 1 wt% or more and 10 wt% or less. % or more and 5 wt % or less is more preferable.

[0199] The conductive additive can form an electrically conductive network in the electrode. This allows the positive electrode active material layer to maintain an electrical conduction path between the positive electrode active materials. By adding an auxiliary, an active material layer having high electrical conductivity can be realized.

[0200] Examples of the conductive assistant include natural graphite, artificial graphite such as mesocarbon microbeads, carbon Examples of carbon fibers include mesophase pitch carbon fibers. Carbon fibers such as isotropic pitch-based carbon fibers can be used. Carbon nanofibers, carbon nanotubes, etc. can be used. The nanotubes can be produced, for example, by a vapor phase growth method. For example, carbon black (acetylene black (AB) etc.), graphite particles Carbon materials such as graphene and fullerene can be used. Metal powders and fibers such as nickel, aluminum, silver, and gold, as well as conductive ceramic materials, etc. can be used.

[0201] A graphene compound may be used as the conductive assistant.

[0202] Graphene compounds have excellent electrical properties, including high electrical conductivity, as well as high flexibility and In addition, the graphene may have excellent physical properties such as high mechanical strength. Graphene compounds have a planar shape. Graphene compounds enable surface contact with low contact resistance. In addition, even if the material is thin, it can have very high conductivity, and a small amount can be used efficiently in the active material layer. A conductive path can be formed. Therefore, graphene compounds are used as conductive additives. This is preferable because it is possible to increase the contact area between the active material and the conductive assistant. In addition, it is preferable because it may be possible to reduce electrical resistance. For example, it is particularly preferred to use graphene or multi-graphene or RGO.

[0203] When using an active material with a small particle size, for example, 1 μm or less, the specific surface area of ​​the active material In such a case, the active material is required to have a large number of conductive paths. The use of a graphene compound that can efficiently form a conductive path even in a small amount is particularly advantageous. Preferred.

[0204] In the following, as an example, a graphene compound is used as a conductive assistant in the active material layer 102. An example of the cross-sectional configuration in this case will be described.

[0205] 6A shows a vertical cross-sectional view of the active material layer 102. The active material layer 102 is made of granular active material 1 03, a graphene compound 321 as a conductive assistant, and a binder 104. For example, graphene or multi-graphene may be used as the graphene compound 321. Here, the graphene compound 321 preferably has a sheet shape. The graphene compound 321 may be a multi-graphene or / and a plurality of graphenes. may be partially overlapped to form a sheet.

[0206] In the vertical cross section of the active material layer 102, as shown in FIG. 6(A), In FIG. 6(A), the sheet-like graphene compound 321 is dispersed almost uniformly. The graphene compound 321 is shown in bold in the figure, but in reality it is a single layer of carbon molecules or The graphene compounds 321 are thin films having a thickness of multiple layers. The active material 103 is wrapped or covered, or is attached to the surface of a plurality of active material particles 103. Since the electrodes are formed so as to be spaced apart from each other, they are in surface contact with each other.

[0207] Here, a plurality of graphene compounds are bonded to each other to form a mesh-like graphene compound. The graphene compound is then bonded to a graphene sheet (hereinafter referred to as a graphene compound net or a graphene net). When the active material is covered with a graphene net, the graphene net can Therefore, the amount of binder can be reduced. Since it is possible to use or not use the active material in the electrode volume and weight, The ratio of the power storage capacity to the power consumption can be improved. In other words, the capacity of the power storage device can be increased. do.

[0208] Here, graphene oxide is used as the graphene compound 321, and is mixed with an active material to form an active material. After the layer that will become the graphene layer 102 is formed, it is preferable to reduce the layer. In addition, by using graphene oxide, which has extremely high dispersibility in polar solvents, The compound 321 can be dispersed approximately uniformly inside the active material layer 102. The solvent is removed by evaporation from the dispersion medium containing the graphene oxide dispersed in the solution, and the graphene oxide is reduced. Therefore, the graphene compound 321 remaining on the active material layer 102 partially overlaps with each other. By dispersing the particles so that they come into surface contact with each other, a three-dimensional conductive path can be formed. The reduction of graphene oxide may be performed, for example, by heat treatment or by using a reducing agent. You may go.

[0209] Therefore, unlike granular conductive additives such as acetylene black, which come into point contact with the active material, Since the phenyl compound 321 enables surface contact with low contact resistance, it is not a conventional conductive additive. Improves electrical conductivity between the granular active material 103 and the graphene compound 321 with a smaller amount than that of Therefore, the ratio of the active material 103 in the active material layer 102 can be increased. This makes it possible to increase the discharge capacity of the power storage device.

[0210] FIG. 6B shows an enlarged view of the area surrounded by the dashed line in FIG. 6A. The binder 104 is The graphene compound 321 may be present in a layer form on the surface of the active material 103. It is preferable that the binder 104 has a region in contact with the surface of the active material 103. , and is located between the graphene compound 321. In addition, it is preferable that a binder is provided on the active material 103. A graphene compound 321 is provided on the binder 104 .

[0211] <Current collector> The current collector 101 is made of metals such as stainless steel, gold, platinum, aluminum, titanium, and the like, and A material with high electrical conductivity, such as an alloy of these materials, can be used. In the case where the current collector 101 is used as a negative electrode, it is preferable that the current collector 101 does not dissolve at the potential of the positive electrode. In this case, it is preferable that the silicon oxide is not alloyed with carrier ions such as lithium ions. Elements that improve heat resistance, such as titanium, neodymium, scandium, and molybdenum, are added. Aluminum alloys that react with silicon to form silicide can be used. The metal element may be a metal element that reacts with silicon to form a silicide. These include zirconium, titanium, hafnium, vanadium, niobium, tantalum, and chromium. , molybdenum, tungsten, cobalt, nickel, etc. The current collector 101 may be in the form of a foil, a plate, Shapes such as sheet, mesh, punched metal, and expanded metal are used as appropriate. The current collector 101 may preferably have a thickness of 5 μm or more and 30 μm or less. .

[0212] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0213] (Embodiment 4) In this embodiment, a power storage device to which the electrode of one embodiment of the present invention can be applied will be described. Reveal.

[0214] As an example of a power storage device of one embodiment of the present invention, a lithium-ion battery or the like that uses an electrochemical reaction secondary batteries, electric double layer capacitors, redox capacitors and other electrochemical capacitors, Examples of the battery include a gas battery and a fuel cell.

[0215] <Thin storage battery> FIG. 7 shows a thin storage battery as an example of a power storage device. If the structure has the above, when the device is mounted on an electronic device having at least a part having flexibility, This allows the battery to bend in accordance with the deformation of the electronic device.

[0216] FIG. 7 shows an external view of a storage battery 500, which is a thin storage battery. In addition, FIG. 8(A) and FIG. 8 7B shows a cross section taken along the line A1-A2 and a cross section taken along the line B1-B2 shown in FIG. 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 504 and a negative electrode 506 having a negative electrode active material layer 505, a separator 507, and an electrolyte 5 The battery has a positive electrode 503 and a negative electrode 508 provided in the exterior body 509. A separator 507 is provided between the battery 501 and the battery 6. The exterior body 509 contains an electrolyte 508. is filled with.

[0217] The solvent of the electrolytic solution 508 is preferably an aprotic organic solvent, for example, ethylene carbonate. Carbonate (EC), Propylene Carbonate (PC), Butylene Carbonate, Chloro Ethylene carbonate, vinylene carbonate, gamma-butyrolactone, gamma-valerolactone Dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl Carbonate (EMC), methyl formate, methyl acetate, methyl butyrate, 1,3-dioxane, 1,4-dioxane, dimethoxyethane (DME), dimethyl sulfoxide, diethyl ethane ether, methyl diglyme, acetonitrile, benzonitrile, tetrahydrofuran, One of these, ruforan, sultone, etc., or any combination and ratio of two or more of these It can be used at a rate.

[0218] In addition, by using a polymer material that gels as a solvent for the electrolyte, the resistance to leakage, etc. Safety is improved. In addition, it is possible to make the secondary battery thinner and lighter. Representative examples of materials include silicone gel, acrylic gel, acrylonitrile gel, and poly Ethylene oxide gel, polypropylene oxide gel, fluorine polymer gel etc.

[0219] In addition, a flame-retardant and non-volatile ionic liquid (room-temperature molten salt) is used as the solvent for the electrolyte. By using one or more, the internal temperature of the storage device can be increased due to an internal short circuit or overcharging. Even if the battery is heated, it can prevent the battery from bursting or catching fire. The electrolyte solution is made of cations and anions. Ammonium cations, tertiary sulfonium cations, and quaternary phosphonium cations Aliphatic onium cations such as imidazolium cations and pyridinium cations The aromatic cations are also used as anions in the electrolyte. Anions, monovalent methide anions, fluorosulfonate anions, perfluoroalkyl sulfonic acid anion, tetrafluoroborate anion, perfluoroalkyl borate anion phosphate anion, hexafluorophosphate anion, or perfluoroalkyl phosphat ate anion, etc.

[0220] In addition, when lithium ions are used as a carrier for the electrolyte dissolved in the above-mentioned solvent, For example, LiPF6, LiClO4, LiAsF6, LiBF4, LiAlCl4, L iSCN, LiBr, LiI, Li2SO4, Li2B 10 Cl 10 , Li2B 12 Cl 12 , LiCF3SO3, LiC4F9SO3, LiC(CF3SO2)3, LiC(C 2F5SO2)3, LiN(CF3SO2)2, LiN(C4F9SO2)(CF3SO 2) One or more lithium salts such as LiN(C2F5SO2)2 can be used in any combination and ratio.

[0221] The electrolyte used in the electricity storage device is free of granular waste and elements other than the constituent elements of the electrolyte (hereinafter simply referred to as " It is preferable to use a highly purified electrolyte solution having a low content of impurities. Specifically, the weight ratio of impurities to the electrolyte is 1% or less, preferably 0.1% or less, more preferably 1% or less. It is preferably 0.01% or less.

[0222] In addition, the electrolyte contains vinylene carbonate, propane sultone (PS), and tert-butyl Addition of benzene (TBB), fluoroethylene carbonate (FEC), LiBOB, etc. The concentration of the additive may be, for example, 0.1 weight % or more relative to the total solvent. The upper limit should be 5 weight % or less.

[0223] Alternatively, a polymer gel electrolyte may be used in which a polymer is swollen with an electrolytic solution.

[0224] The polymer may be, for example, a polyalkylene oxide such as polyethylene oxide (PEO). Polymers with side structures, PVDF, polyacrylonitrile, etc., and their For example, a copolymer containing PVDF and hexafluoropropylene ( PVDF-HFP, a copolymer of PVDF and HFP, can be used. The polymer may have a porous shape.

[0225] In addition, instead of the electrolyte solution, a solid electrolyte having an inorganic material such as a sulfide or oxide is used. It is possible to use a solid electrolyte containing a polymer material such as PEO (polyethylene oxide). When a solid electrolyte is used, the installation of a separator or spacer becomes unnecessary. Since the entire battery can be made solid, there is no risk of leakage, and safety is dramatically improved.

[0226] The separator 507 may be made of, for example, paper, nonwoven fabric, glass fiber, ceramics, or Nylon (polyamide), Vinylon (polyvinyl alcohol fiber), polyester, a Use synthetic fibers such as acrylic, polyolefin, and polyurethane. This can be done.

[0227] The separator 507 is processed into a bag shape and encases either the positive electrode 503 or the negative electrode 506. For example, as shown in FIG. 9(A), the positive electrode 503 is sandwiched between the positive electrode 503 and the positive electrode 504. The separator 507 is folded in half as shown in FIG. 1, and the sealing portion 51 is formed on the outer side of the area overlapping with the positive electrode 503. By sealing with 4, the positive electrode 503 can be reliably supported within the separator 507. Then, as shown in FIG. 9(B), the positive electrode 503 and the negative electrode 505 wrapped in a separator 507 are 06 are alternately stacked and placed in an exterior body 509 to form a storage battery 500. It would be good to do so.

[0228] Next, aging after the storage battery is manufactured will be described. It is preferable to carry out aging. An example of the aging conditions is described below. The charging rate is between 0.001C and 0.2C. The temperature is, for example, above room temperature and 50 Here, if the reaction potential of the positive electrode or the negative electrode exceeds the range of the potential window of the electrolyte 508, In this case, the electrolyte may decompose due to charging and discharging of the battery. If gas is generated, it accumulates in the cell and the electrolyte comes into contact with the electrode surface. In other words, the effective reaction area of ​​the electrode is reduced, and the effective This corresponds to a higher resistance.

[0229] In addition, if the resistance becomes too high, the negative electrode potential will drop, causing lithium intercalation into the graphite. At the same time as the lithium penetration occurs, lithium deposition on the graphite surface also occurs. For example, after lithium is deposited, a film may grow on the surface, causing a decrease in the amount of lithium. If the lithium is removed, the lithium deposited on the surface cannot be re-eluted, and the amount of lithium that does not contribute to the capacity increases. In addition, if the deposited lithium physically collapses and loses electrical continuity with the electrode, However, lithium that does not contribute to the capacity is generated. Therefore, the potential of the negative electrode is the charging voltage It is preferable to degas before the potential rises to the lithium potential.

[0230] After degassing, the mixture is heated to a temperature higher than room temperature, preferably 30° C. to 60° C. More preferably, the temperature is 35° C. or higher and 50° C. or lower, for example, 1 hour or higher and 100 hours or lower. During the first charge, the electrolyte decomposed on the surface is transferred to the graphite surface. For example, by keeping the temperature higher than room temperature after degassing, In some cases, the formed coating may become dense.

[0231] FIG. 10 shows an example of welding a current collector to a lead electrode. As shown in FIG. 10(A), The positive electrode 503 wrapped in the separator 507 and the negative electrode 506 are stacked alternately. The current collector 501 is connected to a positive electrode lead electrode 510, the negative electrode current collector 504 is connected to a negative electrode lead electrode 511, An example in which a positive electrode current collector 501 is welded to a positive electrode lead electrode 510 is shown in FIG. The positive electrode current collector 501 is welded to the positive electrode lead electrode 512 at a welding area 512 by ultrasonic welding or the like. The positive electrode current collector 501 is welded to the curved portion 510 shown in FIG. By doing so, it is possible to reduce stress caused by the application of external force after the storage battery 500 is manufactured. This makes it possible to improve the reliability of the storage battery 500.

[0232] In the storage battery 500 shown in FIG. 7 and FIG. 8, the positive electrode lead electrode 510 has a positive electrode 503. The positive electrode current collector 501 is connected to the negative electrode lead electrode 511, and the negative electrode current collector 504 is connected to the negative electrode 506. The positive electrode serves as a terminal for electrical contact with the outside. The negative electrode current collector 501 and the negative electrode current collector 504 can also serve as the same. In that case, a lead electrode is not used. The positive electrode current collector 501 and the negative electrode current collector 504 are partially exposed to the outside from the exterior body 509. The components may be arranged so that

[0233] In addition, in FIG. 7, the positive electrode lead electrode 510 and the negative electrode lead electrode 511 are arranged on the same side. However, as shown in FIG. 11, the positive electrode lead electrode 510 and the negative electrode lead electrode 511 are arranged on different sides. In this way, the storage battery according to one embodiment of the present invention allows the lead electrodes to be freely arranged. Therefore, the design freedom is high. In addition, the productivity of a product using the storage battery according to one embodiment of the present invention can be improved. can be increased.

[0234] In the storage battery 500, the exterior body 509 is made of, for example, polyethylene, polypropylene, Aluminium, steel, etc. are applied to a membrane made of a material such as polycarbonate, ionomer or polyamide. A thin metal film made of stainless steel, copper, nickel, or other material with excellent flexibility is applied, and then an exterior is applied to the thin metal film. The outer surface of the body is covered with an insulating synthetic resin film made of polyamide resin, polyester resin, etc. A layered film may be used.

[0235] In FIG. 8, as an example, the number of pairs of facing positive electrode active material layers and negative electrode active material layers is set to five. However, the number of electrode pairs is not limited to five, and may be more or less. When the number of electrode layers is large, the storage battery can have a larger capacity. When the number of layers is small, the storage battery can be made thin and has excellent flexibility.

[0236] In the above configuration, the exterior body 509 of the secondary battery has a minimum curvature radius of, for example, 3 mm or more. The deformation can be made to be 30 mm or less, and more preferably, 3 mm to 10 mm. The film that is the exterior body of the secondary battery is made up of one or two sheets, and has a laminated structure. In the case of a secondary battery, the cross-sectional structure of the curved battery is the two curves of the film that is the exterior body. The structure is sandwiched between the two.

[0237] The radius of curvature of a surface will be described with reference to FIG. 12. In FIG. 12(A), a curved surface 170 A part of a curve 1702 included in a surface 1700 is cut into a plane 1701 that cuts through 0. Approximate the arc and set the radius of the circle as the radius of curvature 1703 and the center of the circle as the center of curvature 1704. FIG. 12B shows a top view of the curved surface 1700. FIG. 12C shows the curved surface 1700 on a flat surface 1701. The cross-sectional view of 1700 is shown. When cutting a curved surface with a plane, the angle of the plane to the curved surface is The radius of curvature of the curve that appears in the cross section will differ depending on the cutting position and the cutting angle. The smallest radius of curvature is taken as the radius of curvature of the surface.

[0238] The secondary battery, which sandwiches electrodes and electrolyte (1805) between two films as the exterior body, is curved. 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 is smaller than the radius of curvature 1804 of the film 1803 on the side farther from the center of curvature 1800 ( FIG. 13(A). When a secondary battery is curved to have an arc-shaped cross section, the center of curvature is 1800°. The surface of the film is subjected to compressive stress, and the surface of the film far from the center of curvature 1800 is subjected to tension stress. Tensile stress is applied (Figure 13(B)). The pattern formed on the surface of the exterior body is a concave or convex pattern. When this is formed, even if compressive or tensile stress is applied, the effects of strain are not observed. Therefore, the secondary battery can be prevented from being damaged by the external casing on the side 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 or less. It can be modified so that it is less than m.

[0239] The cross-sectional shape of the secondary battery is not limited to a simple arc shape, and may be a shape that includes a partial arc. For example, the shape shown in FIG. 13(C), a wavy shape (FIG. 13(D)), an S-shape, etc. In the case where the curved surface of the secondary battery has a shape having a plurality of centers of curvature, Among the radii of curvature at each of the centers of curvature, the surface with the smallest radius of curvature is 2 For example, the minimum radius of curvature of the outer casing closest to the center of curvature of one outer casing is 3 mm or more and 30 mm or less. The deformation can be more preferably within the range of 3 mm to 10 mm.

[0240] Next, various examples of lamination of the positive electrode, the negative electrode and the separator are shown.

[0241] FIG. 16A shows an example in which six layers of positive electrodes 111 and six layers of negative electrodes 115 are stacked. A positive electrode active material layer 122 is provided on one surface of a positive electrode current collector 121 of the electrode 111. The negative electrode 115 has a negative electrode current collector 125 on one surface of which a negative electrode active material layer 126 is provided.

[0242] In the configuration shown in FIG. 16(A), the positive electrode 111 does not have a positive electrode active material layer 122. The positive electrode 115 is placed on the positive electrode 11 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 laminated in this order. The surfaces of the negative electrodes 115 that do not have the negative electrode active material layer 122 are called the surfaces of the negative electrodes 115 that do not have the negative electrode active material layer 126. The contact surface between the metals can be created by the active material and the separator. The coefficient of friction can be reduced compared to the contact surface of the other surface.

[0243] Therefore, when the secondary battery is curved, the surface of the positive electrode 111 not having the positive electrode active material layer 122 is flat. In addition, the surfaces of the negative electrodes 115 that do not have the negative electrode active material layer 126 slide against each other, so that the inner and outer diameters of the curve The stress caused by the difference in the curvature can be released. When bending the battery 500, the battery 500 is located on the inside of the bending portion of the exterior body 509. This refers to the radius of curvature of the surface. Therefore, deterioration of the storage battery 500 can be suppressed. In addition, the storage battery 500 can be made highly reliable.

[0244] FIG. 16(B) shows an example of lamination of a positive electrode 111 and a negative electrode 115 different from that shown in FIG. 16(A). In the configuration shown in FIG. 16(B), a positive electrode active material layer 122 is provided on both sides of a positive electrode current collector 121. As shown in FIG. 16(B), the positive electrode current collector By providing the positive electrode active material layer 122 on both sides of the positive electrode active material layer 121, the capacity per unit volume of the storage battery 500 is The amount can be increased.

[0245] FIG. 16(C) shows an example of lamination of a positive electrode 111 and a negative electrode 115 different from that shown in FIG. 16(B). In the configuration shown in FIG. 16(C), a negative electrode active material layer 126 is provided on both sides of a negative electrode current collector 125. As shown in FIG. 16(C), the negative electrode current collector By providing the negative electrode active material layer 126 on both sides of the negative electrode active material layer 125, the capacity per unit volume of the storage battery 500 is increased. The amount can be increased further.

[0246] In the configuration shown in FIG. 16, the separator 123 wraps the positive electrode 111 in a bag shape. However, the present invention is not limited to this. An example having a separator 123 with a different structure is shown. In the structure shown in FIG. 17(A), the positive electrode active A sheet-like separator 123 is provided between each of the material layers 122 and the negative electrode active material layers 126. The configuration shown in FIG. 17(A) differs from the configuration shown in FIG. Six layers of electrodes 111 and six layers of negative electrodes 115 are laminated, and six layers of separators 123 are provided.

[0247] FIG. 17B shows an example in which a separator 123 different from that in FIG. 17A is provided. In the configuration shown in FIG. 17(B), one separator 123 is provided between the positive electrode active material layer 122 and the negative electrode active material layer 123. The point where the layer 126 is folded back multiple times so as to be sandwiched between the layers 126 is shown in FIG. The structure shown in FIG. 17(B) is different from the structure shown in FIG. 17(A). It can also be said that the layer is connected by extending the connector 123. In the configuration, six layers of positive electrodes 111 and six layers of negative electrodes 115 are laminated, and a small number of separators 123 are used. It is preferable that the separator 123 is folded at least five times. 2 and the negative electrode active material layer 126, but also extends to multiple positive electrodes 1 11 and the negative electrode 115 may be bound together.

[0248] Alternatively, the positive electrode, the negative electrode, and the separator may be laminated as shown in FIG. FIG. 18(A) is a cross-sectional view of the first electrode assembly 130, and FIG. 18(B) is a cross-sectional view of the second electrode assembly 131. 18(C) is a cross-sectional view taken along dashed line A1-A2 in FIG. For clarity of illustration, the first electrode assembly 130, the second electrode assembly 131 and the separator An excerpt from data 123 is shown below.

[0249] As shown in FIG. 18(C), the storage battery 500 includes a plurality of first electrode assemblies 130 and a plurality of The second electrode assembly 131 has a number of second electrode assemblies 131.

[0250] As shown in FIG. 18(A), in the first electrode assembly 130, the positive electrode current collector 121 has a A positive electrode 111a having a positive electrode active material layer 122, a separator 123, and both sides of a negative electrode current collector 125 The negative electrode 115a having the negative electrode active material layer 126 on both sides of the separator 123 and the positive electrode current collector 121 The positive electrode 111a having the positive electrode active material layer 122 on the surface is laminated in this order. As shown in FIG. 1B, in the second electrode assembly 131, a negative electrode active material is provided on both sides of the negative electrode current collector 125. A layer 126 is formed on both sides of the negative electrode 115a, the separator 123, and the positive electrode current collector 121. A positive electrode 111a having a porous layer 122, a separator 123, and a negative electrode current collector 125 are provided on both sides thereof. A negative electrode 115a having a material layer 126 is laminated in this order.

[0251] Further, as shown in FIG. 18(C), a plurality of first electrode assemblies 130 and a plurality of second The electrode assembly 131 is covered by a wound separator 123 .

[0252] [Coin-type battery] Next, as an example of the power storage device, an example of a coin-type storage battery will be described with reference to FIG. FIG. 14(A) is an external view of a coin-type (single-layer flat) storage battery, and FIG. 14(B) is , its cross-sectional view.

[0253] The coin-type storage battery 300 has a positive electrode can 301 that also serves as a positive electrode terminal and a negative electrode can 302 that also serves as a negative electrode terminal. 302 is insulated and sealed by a gasket 303 made of polypropylene or the like. The positive electrode 304 is composed of a positive electrode current collector 305 and a positive electrode active material layer 306 provided in contact with the positive electrode current collector 305. It is formed by:

[0254] The negative electrode 307 is made up of a negative electrode current collector 308 and a negative electrode active material It is formed by layer 309 .

[0255] The positive electrode 304 may be the same as that described for the positive electrode 503. The positive electrode active material layer 306 is For the negative electrode 307, see negative electrode 506. The layer 309 may be described with reference to the negative electrode active material layer 505. For the electrolyte, see the description of electrolyte 508.

[0256] The positive electrode 304 and the negative electrode 307 used in the coin-type storage battery 300 are each an active material. The barrier layer need only be formed on one side.

[0257] The positive electrode can 301 and the negative electrode can 302 are made of nickel or aluminum, which are resistant to corrosion by the electrolyte. Metals such as titanium, or their alloys or alloys of these with other metals (e.g. stainless steel In order to prevent corrosion by the electrolyte, nickel or aluminum can be used. The positive electrode can 301 is for covering the positive electrode 304, and the negative electrode can 302 is for covering the negative electrode 305. 07 and electrically connect to each other.

[0258] The negative electrode 307, the positive electrode 304 and the separator 310 are impregnated with an electrolyte, and the negative electrode 307, the positive electrode 304 and the separator 310 are impregnated with an electrolyte. As shown in Fig. 2B, the positive electrode can 301 is placed downward, and the positive electrode 304, the separator 310, and the negative electrode 307 are placed in the same position. The positive electrode can 301 and the negative electrode can 302 are stacked in this order, and the positive electrode can 301 and the negative electrode can 302 are secured together with a gasket 303. The coin-shaped storage battery 300 is manufactured by crimping the wires through a wire cutout.

[0259] [Cylindrical storage battery] Next, a cylindrical storage battery will be shown as an example of a power storage device. The cylindrical storage battery 600 has a positive electrode on the upper surface as shown in FIG. It has a cap (battery cover) 601 and a battery can (outer can) 602 on the side and bottom. The positive electrode cap and the battery can (outer can) 602 are connected with a gasket (insulating packing) 602. It is insulated by 10.

[0260] FIG. 15(B) is a schematic diagram showing a cross section of a cylindrical storage battery. Inside the can 602, a strip-shaped positive electrode 604 and a negative electrode 606 are sandwiched between a separator 605. A wound battery element is provided. Although not shown, the battery element is wound around a center pin. The battery can 602 is closed at one end and open at the other end. The material is nickel, aluminum, titanium, or other metals that are resistant to corrosion by the electrolyte. These and their alloys with other metals (e.g., stainless steel, etc.) can be used. In addition, in order to prevent corrosion by the electrolyte, it is preferable to coat the electrode with nickel, aluminum, or the like. A battery element in which a positive electrode, a negative electrode, and a separator are wound inside a battery can 602. The battery element is sandwiched between a pair of opposing insulating plates 608 and 609. A non-aqueous electrolyte (not shown) is poured into the battery can 602. A coin-type storage battery or the like can be used.

[0261] The positive electrode 604 may be referred to as the positive electrode 503. The negative electrode 606 may be referred to as the negative electrode 506. The positive electrode 604 and the negative electrode 606 may be formed by the method for preparing the electrodes shown in, for example, Embodiment 1. The positive and negative electrodes used in cylindrical storage batteries are wound, It is preferable to form an active material on both sides of the current collector. A negative electrode terminal (negative electrode current collecting lead) 607 is connected to the negative electrode 606. The positive electrode terminal 603 and the negative electrode terminal 607 are both made of a metal material such as aluminum. The positive terminal 603 is connected to a safety valve mechanism 612, and the negative terminal 607 is connected to a battery can 602. The safety valve mechanism 612 is a positive temperature coefficient (PTC) element. Temperature Coefficient) 611 via the positive electrode cap 601 The safety valve mechanism 612 is electrically connected to the battery when the internal pressure of the battery exceeds a predetermined threshold. In this case, the electrical connection between the positive electrode cap 601 and the positive electrode 604 is cut off. The PTC element 611 is a thermal resistance element whose resistance increases when the temperature increases. The PTC element is made of titanium oxide. Barium (BaTiO3) based semiconductor ceramics and the like can be used.

[0262] When winding electrodes in a cylindrical storage battery as shown in Figure 15, large amounts of In addition, when the electrode winding body is housed in a housing, the electrode always has a winding shaft. Even if a large stress acts on the electrode, the active material This can prevent the material from cleaving.

[0263] In this embodiment, the storage battery is a coin type, a cylindrical type, and a thin type. However, other types of batteries, such as sealed batteries and rectangular batteries, can be used. In addition, a structure in which a positive electrode, a negative electrode, and a separator are laminated in multiple layers, For example, other examples of the storage battery are shown in Figs. vinegar.

[0264] [Example of a thin storage battery configuration] 19 and 20 show an example of the configuration of a thin storage battery. The battery 3 has a negative electrode 994 , a positive electrode 995 , and a separator 996 .

[0265] The wound body 993 has a negative electrode 994 and a positive electrode 995 overlapped with a separator 996 sandwiched therebetween. The laminated sheet is then wound. The wound body 993 is placed in a rectangular sealed container or the like. A square secondary battery is produced by covering the battery with a material such as a plastic.

[0266] The number of layers of the negative electrode 994, the positive electrode 995, and the separator 996 may be as large as necessary. The negative electrode 994 is connected to the lead electrode 997 and the The positive electrode 995 is connected to a negative electrode collector (not shown) via one of the leads 998. The other of the electrode 997 and the lead electrode 998 is connected to a positive electrode collector (not shown). .

[0267] The storage battery 990 shown in FIG. 19(B) and FIG. 19(C) is a film 981 that serves as an exterior body. The film 982 having the recess is bonded to the film 982 by thermocompression or the like to form a space. The winding body 993 includes a lead electrode 997 and a lead The film 981 and the film 982 having the recesses are electrically connected to each other. It is impregnated with liquid.

[0268] The film 981 and the film 982 having the recesses are made of a metal material such as aluminum. The film 981 and the film 982 having the recesses can be made of a metal or resin material. If a resin material is used as the material for the recess 981, when an external force is applied, the recess 981 and the film 982 are The film 982 having the above structure can be deformed to produce a flexible storage battery. can be done.

[0269] In addition, although Fig. 19(B) and Fig. 19(C) show examples using two films, A space is formed by folding one sheet of film, and the above-mentioned wound body 9 is inserted into the space. 93 may also be accommodated.

[0270] In addition, the exterior body of the power storage device and the sealing container are made of a resin material, etc., so that the device has flexibility. However, when the exterior body or the sealing container is made of a resin material, The parts that are connected to the outside are made of conductive material.

[0271] For example, another example of a thin storage battery having flexibility is shown in FIG. 20. The wound body 9 in FIG. 93 is the same as that shown in FIG. 19(A), so detailed description will be omitted. .

[0272] The storage battery 990 shown in FIG. 20(B) and FIG. 20(C) has the above-described The winding body 993 includes a lead electrode 997 and a lead The electrode 998 is impregnated with an electrolyte inside the exterior bodies 991 and 992. The outer casing 992 can be made of a metal material such as aluminum or a resin material. If resin material is used as the material of 991 and 992, the exterior body 9 91, 992 can be deformed to produce a thin storage battery having flexibility. do.

[0273] By using an electrode including an active material according to one embodiment of the present invention in a flexible thin storage battery, This means that even if stress is applied to the electrodes by repeatedly bending a thin storage battery, the battery will remain active. This can prevent the material from being cleaved.

[0274] As a result, the active material having at least a part of the cleavage plane covered with graphene can be used for an electrode. As a result, it is possible to suppress a decrease in the battery voltage and a decrease in the discharge capacity. The cycle characteristics of the battery during charging and discharging can be improved.

[0275] [Example of energy storage system structure] A structural example of the power storage system will be described with reference to Figs. 21 to 23. The power system refers to, for example, a device equipped with a power storage device.

[0276] 21(A) and 21(B) are diagrams showing the external appearance of the power storage system. The system includes a circuit board 900 and a storage battery 913. The storage battery 913 is provided with a label 91. 21B, the power storage system has a terminal 951 and , a terminal 952 , an antenna 914 , and an antenna 915 .

[0277] The circuit board 900 has a terminal 911 and a circuit 912. The terminal 911 is connected to the terminal 95. 1, terminal 952, antenna 914, antenna 915, and circuit 912. A plurality of terminals 911 are provided, and each of the plurality of terminals 911 is connected to a control signal input terminal, a power supply terminal, It may also be a terminal.

[0278] The circuit 912 may be provided on the back surface of the circuit board 900. The antenna 915 is not limited to a coil shape, but may be, for example, a wire or plate shape. Planar antennas, aperture antennas, traveling wave antennas, EH antennas, magnetic field antennas, induction Alternatively, an antenna such as an electric antenna may be used. 5 may be a flat conductor. This flat conductor functions as one of the conductors for electric field coupling. In other words, one of the two conductors of the capacitor is The antenna 914 or the antenna 915 may be activated. Not only that, but it is also possible to exchange power using an electric field.

[0279] The line width of antenna 914 is preferably larger than the line width of antenna 915. This allows the amount of power received by the antenna 914 to be increased.

[0280] The storage system includes a layer 9 between the antenna 914 and the antenna 915 and the storage battery 913. The layer 916 has a function of shielding the electromagnetic field caused by the battery 913, for example. The layer 916 may be made of, for example, a magnetic material.

[0281] The structure of the power storage system is not limited to the structure shown in FIG.

[0282] For example, as shown in Figs. 22(A-1) and 22(A-2), In the storage battery 913 shown in FIG. 21(B), an antenna is provided on each of a pair of opposing surfaces. FIG. 22(A-1) is an external view seen from one side of the pair of faces. 2(A-2) is an external view seen from the other side of the pair of surfaces. 21(A) and 21(B) are the same as those in the storage system shown in FIG. The explanation of the power storage system shown in FIG. 1(B) can be used as appropriate.

[0283] As shown in FIG. 22(A-1), a layer 916 is sandwiched between one of a pair of surfaces of a storage battery 913. As shown in FIG. 22(A-2), an antenna 914 is provided on one side of the storage battery 913, and the other side of the storage battery 913 is provided on the other side of the storage battery 913. An antenna 915 is provided on the opposite side of the layer 917. The layer 917 is, for example, a storage battery 913. The layer 917 has a function of blocking electromagnetic fields caused by the electromagnetic waves. There can be.

[0284] By adopting the above structure, the size of both antenna 914 and antenna 915 can be increased. It can be heard.

[0285] Or, as shown in FIG. 22(B-1) and FIG. 22(B-2), In the storage battery 913 shown in FIG. 21(B), a separate antenna is attached to each of a pair of opposing surfaces. FIG. 22(B-1) is an external view of the pair of surfaces as viewed from one side, FIG. 22(B-2) is an external view seen from the other side of the pair of faces. The same parts as those in the storage system shown in FIG. 21(A) and FIG. 21(B) are shown in FIG. The description of the power storage system shown in FIG. 21B can be used as appropriate.

[0286] As shown in FIG. 22(B-1), a layer 916 is sandwiched between one of the pair of surfaces of a storage battery 913. An antenna 914 and an antenna 915 are provided, and as shown in FIG. An antenna 918 is provided on the other of the pair of surfaces of the antenna 913 with a layer 917 sandwiched therebetween. The antenna 91 has a function of performing data communication with an external device, for example. 8, for example, an antenna having a shape applicable to antenna 914 and antenna 915 is applied. As a communication method between the power storage system and other devices via the antenna 918, The system applies a response method such as NFC that can be used between the energy storage system and other devices. It is possible.

[0287] 23(A), the storage battery 91 shown in FIG. 21(A) and FIG. 21(B) A display device 920 may be provided on the input side of the input terminal 911 via a terminal 919. The label 910 is electrically connected to the display device 920. It is not necessary to use the same parts as those in the power storage system shown in FIG. 21(A) and FIG. 21(B). For this purpose, the description of the power storage system shown in FIG. 21(A) and FIG. 21(B) can be used as appropriate.

[0288] The display device 920 displays, for example, an image indicating whether charging is in progress, an image indicating the amount of stored power, etc. The display device 920 may be, for example, an electronic paper, a liquid crystal display device, an electronic For example, electroluminescence (EL) display devices can be used. By using the polarizer, the power consumption of the display device 920 can be reduced.

[0289] 23(B), the storage battery 91 shown in FIG. 21(A) and FIG. 21(B) A sensor 921 may be provided on the terminal 911 via a terminal 922. Note that the same parts as the power storage system shown in FIG. 21(A) and FIG. 21(B) are used. For this part, the explanation of the power storage system shown in FIG. 21(A) and FIG. 21(B) can be used as appropriate. Cut.

[0290] The sensor 921 may be, for example, a force, a displacement, a position, a velocity, an acceleration, an angular velocity, a rotation speed, a distance Distance, light, liquid, magnetic, temperature, chemicals, sound, time, hardness, electric field, current, voltage, power, radiation Use devices that include the function of measuring line, flow rate, humidity, gradient, vibration, odor, or infrared rays. By providing the sensor 921, for example, Data indicative of the temperature can be detected and stored in the memory of the circuit 912. .

[0291] The battery and the power storage system described in this embodiment include an electrode according to one embodiment of the present invention. This allows the capacity of storage batteries and power storage systems to be increased. It is possible to increase the energy density. It is also possible to improve reliability. It is also possible to extend the life. It can be made easier.

[0292] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0293] (Embodiment 5) In this embodiment, a flexible electrode according to one embodiment of the present invention can be used. An example in which a storage battery having the above structure is mounted in an electronic device will be described.

[0294] FIG. 24 shows an example in which the flexible storage battery described in the fourth embodiment is mounted in an electronic device. As an example of an electronic device to which a flexible power storage device is applied, a television set is Television sets (also called televisions or television receivers), computer monitors, digital digital cameras, digital video cameras, digital photo frames, mobile phones (mobile phones, (also called mobile telephone devices), portable game machines, personal digital assistants, audio playback devices, pachinko machines, etc. Examples include large game consoles.

[0295] In addition, the flexible energy storage device can be attached to the inner or outer walls of a house or building, or to an automobile. It can also be incorporated into curved interior or exterior surfaces of a vehicle.

[0296] FIG. 24A shows an example of a mobile phone. A mobile phone 7400 includes a housing 740. In addition to the display unit 7402 incorporated in the 1, the operation buttons 7403, the external connection port 7404, The mobile phone 7400 includes a speaker 7405, a microphone 7406, and the like. The device has an electrical device 7407.

[0297] FIG. 24B shows the mobile phone 7400 in a curved state. When the 00 is deformed by an external force and curved, the storage battery installed inside The storage device 7407 is also bent. At this time, the bent state of the storage device 7407 is shown in FIG. The power storage device 7407 is a thin storage battery. The power storage device 7407 is fixed in a resistor connected electrically to the current collector 7409. For example, the current collector 7409 is made of copper foil, some of which is made of gallium. The adhesion between the current collector 7409 and the active material layer in contact therewith is improved by alloying the current collector 7409 and the active material layer in contact therewith. This structure is highly reliable even when the cable is bent.

[0298] FIG. 24D shows an example of a bangle-type display device. The portable display device 7100 is 7101, a display unit 7102, operation buttons 7103, and a power storage device 7104. FIG. 24E shows the bent state of the power storage device 7104. When the device is bent and worn on the user's arm, the housing may deform and cause a part of the power storage device 7104 or The total curvature changes. The degree of curvature at any point on the curve is expressed as the radius of the corresponding circle. The value expressed as the radius of curvature is called the curvature, and the reciprocal of the radius of curvature is called the curvature. A part of the main surface of the housing or the power storage device 7104 within a range of 40 mm to 150 mm in diameter Or the entire surface of the power storage device 7104 changes. High reliability can be maintained if the deviation is within the range of 0 mm or less.

[0299] FIG. 24F shows an example of a wristwatch-type portable information terminal. The housing 7201, the display unit 7202, the band 7203, the buckle 7204, the operation button 7 205, an input / output terminal 7206, etc.

[0300] The portable information terminal 7200 is capable of carrying out mobile phone calls, e-mails, viewing and creating documents, playing music, and internet connections. It can run various applications such as internet communication and computer games. Cut.

[0301] The display unit 7202 has a curved display surface, and displays information along the curved display surface. The display unit 7202 is equipped with a touch sensor, and the screen can be operated by touching it with a finger or a stylus. For example, the icon 7 displayed on the display unit 7202 can be operated by touching the By touching 207, the application can be launched.

[0302] The operation button 7205 is used to set the time, turn the power on and off, and turn wireless communication on and off. It supports various functions such as auto-start, silent mode and power saving mode. For example, an operating system built into the portable information terminal 7200 can be Depending on the system, the functions of the operation buttons 7205 can be freely set.

[0303] In addition, the mobile information terminal 7200 is capable of performing short-distance wireless communication according to a communication standard. For example, by communicating with a wireless headset, a hands-free You can also make calls.

[0304] The portable information terminal 7200 also includes an input / output terminal 7206 and is connected to other information terminals via a connector. Data can be exchanged directly through the input / output terminal 7206. The charging operation can be performed by wireless power supply without going through the input / output terminal 7206. You may go.

[0305] The display portion 7202 of the portable information terminal 7200 includes an electrode according to one embodiment of the present invention. For example, the power storage device 7104 shown in FIG. It can be installed in a curved state or in a curved state inside the band 7203. do.

[0306] The portable information terminal 7200 preferably has a sensor. For example, a fingerprint sensor may be used as the sensor. Human body sensors such as sensors for measuring body temperature, touch sensors, pressure sensors, and acceleration sensors. It is preferable that the sensor, etc. be mounted.

[0307] FIG. 24G shows an example of a wristband-type display device. The display device 7300 has a display unit The display device 7300 includes a power storage device of one embodiment of the present invention. The display portion 7304 may be provided with a touch sensor, and may function as a portable information terminal. It is also possible.

[0308] The display surface of the display unit 7304 is curved, and the display is performed along the curved display surface. In addition, the display device 7300 can display the image by short-distance wireless communication according to a communication standard. You can change the situation.

[0309] The display device 7300 also has an input / output terminal, and can directly connect to other information terminals via a connector. It is possible to exchange data. It is also possible to charge the device via the input / output terminal. The charging operation may be performed by wireless power supply without using the input / output terminals.

[0310] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0311] (Embodiment 6) In this embodiment, an example of an electronic device in which a power storage device can be mounted will be described.

[0312] FIG. 25(A) and FIG. 25(B) show an example of a tablet terminal that can be folded in two. The tablet terminal 9600 shown in FIG. 25(A) and FIG. 25(B) includes a housing 9630a, A housing 9630b, a movable part 9640 connecting the housings 9630a and 9630b, and a display unit 9 A display unit 9631 having a display unit 9631a and a display unit 9631b, a display mode changeover switch 96 26, power switch 9627, power saving mode switch 9625, fastener 9629 25(A) shows the tablet terminal 9600 in an open state. 25(A) shows a state in which the tablet terminal 9600 is opened, and FIG. 25(B) shows a state in which the tablet terminal 9600 is closed.

[0313] The tablet terminal 9600 also includes a housing 9630a and a housing 9630b. The power storage unit 9635 is connected to the housing 9630a through the movable portion 9640. It is provided across the body 9630b.

[0314] A part of the display unit 9631a can be used as a touch panel area 9632a. By touching the operation keys 9638 displayed on the display unit 96, data can be input. In 31a, as an example, half of the area has a display function only, and the other half The display unit 96 has a touch panel function, but is not limited to this. The entire area of ​​the display unit 931a may have a touch panel function. The entire surface of 631a is made to display keyboard buttons to serve as a touch panel, and the display section 9631b is made to display It can be used as a display screen.

[0315] In addition, in the display unit 9631b, as in the display unit 9631a, The part of the touch panel can be the area 9632b of the touch panel. Touch the area where the mode display switch button 9639 is displayed with your finger or a stylus. A keyboard button can be displayed on the display portion 9631b.

[0316] In addition, the touch panel area 9632a and the touch panel area 9632b are simultaneously You can also use touch input.

[0317] A display mode changeover switch 9626 is used to change the display orientation, such as vertical or horizontal. You can choose between black and white and color display. The switch 9625 detects the usage of the light detected by the light sensor built into the tablet terminal 9600. The display brightness can be optimized according to the amount of external light at the time. In addition to optical sensors, other sensors such as gyros and acceleration sensors that detect tilt are also used. An ejection device may be built in.

[0318] FIG. 25A shows an example in which the display area of ​​the display portion 9631b is the same as that of the display portion 9631a. However, there is no particular limitation, and one size may be different from the other size. The quality of the display may also be different. For example, one display panel may provide a higher resolution display than the other. It may also be used as a rule.

[0319] FIG. 25(B) shows the tablet terminal in a closed state. The tablet terminal includes a housing 9630 and a solar cell 9 633, a charge / discharge control circuit 9634 including a DCDC converter 9636. The power storage unit according to one embodiment of the present invention is used as the power storage unit 9635.

[0320] In addition, since the tablet terminal 9600 can be folded in two, when not in use, The housing 9630b can be folded so that the housing 9630b and the housing 9630b overlap each other. Since the display units 9631a and 9631b can be protected, the tablet terminal 9600 The durability can be improved. In addition, the power storage unit 9635 using the power storage unit of one embodiment of the present invention It has flexibility and the charge / discharge capacity does not decrease easily even if it is repeatedly bent and stretched. Therefore, it has high reliability. It can provide an excellent tablet device.

[0321] In addition, the tablet terminals shown in Fig. 25(A) and Fig. 25(B) are used in various Functions that display useful information (still images, videos, text images, etc.), calendars, dates, or times A function to display the information on the display unit, and a function to input or edit the information displayed on the display unit. It has a function to input data, a function to control processing by various software (programs), etc. It is possible.

[0322] The solar cell 9633 attached to the surface of the tablet device supplies power to the touch panel. The solar cell 9633 can supply the solar cell 9633 with the following components: The battery 9635 can be efficiently charged by providing the battery on one or both sides of the housing 9630. The power storage unit 9635 may be a lithium-ion battery. This has the advantage of being compact.

[0323] The configuration and operation of the charge / discharge control circuit 9634 shown in FIG. A block diagram is shown in FIG. 25C. A solar cell 9633 and a power storage unit 96 35, DC-DC converter 9636, converter 9637, switches SW1 to SW3, The display unit 9631 is shown, along with a storage battery 9635, a DC-DC converter 9636, and a The inverter 9637 and the switches SW1 to SW3 are connected to the charge / discharge control circuit 9 This corresponds to 634.

[0324] First, an example of operation in which power is generated by the solar cell 9633 using external light will be described. The power generated by the solar cell is converted to a voltage to charge the storage battery 9635. The converter 9636 increases or decreases the voltage. When power from the battery 9633 is used, the switch SW1 is turned on, and the converter 963 7, the voltage is increased or decreased to a voltage required for the display unit 9631. When not displaying in 1, turn SW1 off and SW2 on to turn on the power storage unit 9635. It is sufficient to configure the device so as to perform charging.

[0325] The solar cell 9633 is shown as an example of a power generating means, but is not limited thereto. Storage by other power generation means such as piezoelectric elements and thermoelectric conversion elements For example, the power may be transmitted and received wirelessly (contactlessly). The configuration is a non-contact power transmission module that charges the battery by connecting the battery to the battery, or by combining it with other charging means. You may do so.

[0326] Another example of electronic equipment is shown in FIG. 26. In FIG. 26, a display device 8000 is a display device according to the present invention. 8 is an example of an electronic device including a power storage device 8004 according to one embodiment. 8000 corresponds to a display device for receiving TV broadcasts, and includes a housing 8001, a display unit 8002, a speaker, The power storage device 8004 according to one embodiment of the present invention includes: The display device 8000 is provided inside a housing 8001. The display device 8000 is supplied with power from a commercial power source. It is also possible to use the power stored in the power storage device 8004. Therefore, even when power cannot be supplied from a commercial power source due to a power outage or the like, the present invention according to one aspect of the present invention can be used. The display device 8000 can be used by using the power storage device 8004 as an uninterruptible power supply. become.

[0327] The display unit 8002 is a display device having a light emitting element such as a liquid crystal display device or an organic EL element in each pixel. Optical devices, electrophoretic displays, DMD (Digital Micromirror Devices) ice), PDP (Plasma Display Panel), FED (Field A semiconductor display device such as a 3D Emission Display can be used.

[0328] In addition, display devices are used for TV broadcast reception, personal computers, advertising displays, etc. This includes all display devices for displaying information, such as

[0329] In FIG. 26, a stationary lighting device 8100 includes a power storage device 8 according to one embodiment of the present invention. 8101 is an example of an electronic device using the lighting device 8100. The light source 8102 and the power storage device 8103 are included. In FIG. For example, the light source 101 and the light source 8102 are installed inside a ceiling 8104. 8, the power storage device 8103 may be provided inside the housing 8101. The device 8100 can receive power from a commercial power source, or can store power in a power storage device 8103. The stored power can also be used. Therefore, in the event of a power outage, the supply of power from the commercial power source can be reduced. Even when power cannot be received, the power storage device 8103 of one embodiment of the present invention can be used as an uninterruptible power source. This enables the lighting device 8100 to be used.

[0330] In addition, FIG. 26 illustrates a lighting device 8100 that is installed on a ceiling 8104. However, in the power storage device of one embodiment of the present invention, in addition to the ceiling 8104, for example, the side wall 8105, the floor The present invention can be applied to a lighting device installed in a fixed position such as a desk 8106 or a window 8107. It can also be used in upper lighting devices.

[0331] In addition, the light source 8102 can be an artificial light source that artificially obtains light using electricity. Specifically, this applies to incandescent lamps, discharge lamps such as fluorescent lamps, and light-emitting diodes and organic electroluminescence (EL) elements. An example of the artificial light source is a light element.

[0332] In FIG. 26, an air conditioner having an indoor unit 8200 and an outdoor unit 8204 is 8 is an example of an electronic device including a power storage device 8203 according to one embodiment of the present invention. The indoor unit 8200 includes a housing 8201, an air outlet 8202, a power storage device 8203, and the like. In the example shown in FIG. 1, the power storage device 8203 is provided in the indoor unit 8200. The electric device 8203 may be provided in an outdoor unit 8204. The power storage device 8203 may be provided in both the outdoor units 8204. The power supply can be supplied from a commercial power source, or the power stored in the power storage device 8203 can be used. In particular, both the indoor unit 8200 and the outdoor unit 8204 are provided with a power storage device 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 power storage device 8203 of one embodiment of the present invention as an uninterruptible power supply, The use of conditioners will be possible.

[0333] In addition, in Figure 26, a separate type air conditioner consisting of an indoor unit and an outdoor unit is shown. However, an integrated air conditioner that has both the indoor and outdoor functions in a single housing is also shown. The power storage device of one embodiment of the present invention can also be used for the conditioner.

[0334] In FIG. 26 , an electric refrigerator-freezer 8300 includes a power storage device 8304 according to one embodiment of the present invention. Specifically, an electric refrigerator-freezer 8300 includes a housing 8301, The door for a refrigerator 8302, the door for a freezer 8303, a power storage device 8304, and the like are included. A power storage device 8304 is provided inside a housing 8301. The power supply can be received from a commercial power source, or the power stored in the power storage device 8304 can be used. Therefore, when power cannot be supplied from commercial power sources due to a power outage, etc. Even in such a case, the power storage device 8304 of one embodiment of the present invention can be used as an uninterruptible power supply. It will be possible to use 8300 refrigerators / freezers.

[0335] Among the above-mentioned electronic devices, high-frequency heating devices such as microwave ovens and electric rice cookers The child devices require high power for a short period of time. Therefore, the power that cannot be supplied by the commercial power supply is supplemented. By using a power storage device according to one embodiment of the present invention as an auxiliary power source for supporting This can prevent the commercial power breaker from tripping when using the device.

[0336] In addition, during periods when electronic devices are not in use, the total amount of power that can be supplied by commercial power suppliers is also During periods when the ratio of the amount of electricity actually used (called the electricity usage rate) is low, By storing electricity in the electrical equipment, it is possible to prevent the power usage rate from increasing outside the above-mentioned time periods. For example, in the case of the electric refrigerator-freezer 8300, when the temperature is low, the refrigerator compartment door 83 02, during the night when the freezer door 8303 is not opened or closed, power is supplied to the power storage device 8304. Then, as the temperature rises, the refrigerator door 8302 and the freezer door 8303 open and close. During the daytime, when the electricity is consumed, the power storage device 8304 is used as an auxiliary power source. The rate can be kept low.

[0337] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0338] (Embodiment 7) In this embodiment, an example in which a power storage device is mounted on a vehicle will be described.

[0339] In addition, by installing a power storage device in a vehicle, it can be used as a hybrid vehicle (HEV) or electric vehicle (EV). or next-generation clean energy vehicles such as plug-in hybrid vehicles (PHEVs) It can be realized.

[0340] 27A and 27B show examples of vehicles using one embodiment of the present invention. The 8400 is an electric vehicle that uses an electric motor as a power source for running. The vehicle can be powered by either an electric motor or an engine. A hybrid vehicle. By using one embodiment of the present invention, a vehicle with a long driving range can be realized. The automobile 8400 also has a power storage device. The power storage device can be an electric motor. It not only drives the 8406, but also the headlights 8401 and room lights (not shown). It is possible to supply power to the light emitting device.

[0341] In addition, the power storage device can be used to store information such as a speedometer and a tachometer of the automobile 8400. The power storage device can supply power to the navigation device of the automobile 8400. The present invention can provide power to semiconductor devices such as gating systems.

[0342] The automobile 8500 shown in FIG. 27B is a power storage device that is plugged in to the automobile 8500. It is possible to charge the battery by receiving power from an external charging facility using a contactless charging method or other methods. FIG. 27(B) shows a case where a charging device mounted on a vehicle 8500 is connected to a ground-mounted charging device 8021. The power storage device 8024 is shown being charged via a cable 8022. For charging methods and connector specifications, please refer to the specifications of CHAdeMO (registered trademark) and Combo. The charging device 8021 is a charging station installed in a commercial facility. For example, plug-in technology can be used to connect the power source to the outside. The power storage device 8024 mounted on the automobile 8500 can be charged by the power supply. Charging is performed by converting AC power to DC power via a converter such as an AC / DC converter. It is possible to do so.

[0343] Although not shown, a power receiving device is mounted on the vehicle and receives power from a ground power transmitting device in a non-contact manner. In this case, the power transmission device is installed on the road or on the exterior wall. By incorporating this, charging can be done not only when the vehicle is stopped but also while the vehicle is moving. In addition, the vehicle exterior may be provided with a power supply. A solar cell may be provided in the vehicle so that the power storage device can be charged when the vehicle is stopped or traveling. To supply power in the above, an electromagnetic induction method or a magnetic resonance method can be used.

[0344] According to one embodiment of the present invention, the cycle characteristics of a power storage device can be improved, and the reliability can be improved. Furthermore, according to one embodiment of the present invention, the characteristics of the power storage device can be improved, Therefore, the power storage device itself can be made smaller and lighter. This contributes to reducing the weight of the vehicle, which can improve the cruising distance. The on-board power storage device can also be used as a power supply source for something other than the vehicle. This allows avoiding the use of commercial power during peak hours.

[0345] This embodiment mode can be implemented in appropriate combination with other embodiment modes. EXAMPLES

[0346] In this example, a power storage device was charged and discharged using an electrode of one embodiment of the present invention. The characteristics will be explained.

[0347] As electrodes, an electrode M, an electrode N, and an electrode O were prepared.

[0348] <Synthesis of particles containing lithium manganese nickel oxide> Lithium manganese nickel oxide was synthesized. The raw materials were Li2CO3 and MnCO 3. NiO was used, and the molar ratio was Li2CO3:MnCO3:NiO=0.84. The mixture was weighed out to give a ratio of 0.8062:0.318.

[0349] Next, the weighed raw materials were mixed. After that, they were heated at 1000°C. Lithium manganese nickel oxide was then synthesized. The resulting lithium manganese nickel The oxide was subjected to a crushing treatment using a bead mill.

[0350] Next, the surface of the obtained lithium manganese nickel oxide was coated with a graphene compound. First, water was added to graphene oxide to prepare a dispersion. 160 ml was added to make the concentration of the graphene oxide dispersion 32.5 g / l.

[0351] Next, lithium manganese nickel oxide was added to the graphene oxide dispersion liquid. The graphene oxide dispersion was mixed with 260 g of lithium manganese. Nickel oxide was added. That is, 2% of the weight of the positive electrode active material was added. After that, heat treatment was performed at 50°C under reduced pressure to obtain lithium oxynitride coated with graphene. Sample A was obtained, which was manganese nickel oxide.

[0352] Next, to reduce the graphene oxide, 240 g of sample A and 40.5 g of ascorbic acid were added. acid, 9.36 g of lithium hydroxide monohydrate, 1029 ml of ethanol, and 9.3 6g of water was added and mixed. The resulting mixture was spray-dried to obtain a mixture. The powder was collected from the mixture and then heat-treated at 170°C under reduced pressure.

[0353] Through the above steps, particles B containing lithium manganese nickel oxide were produced.

[0354] <Formation of Active Material Layer 212> Next, a slurry was prepared. The prepared particles B, acetylene black (AB), and PV dF and Particle B:AB:PVdF = 90:5:5 (weight ratio) were mixed and used as a solvent. Then, NMP was added and kneading was performed. The solid content of the slurry was 47% by weight.

[0355] Next, the slurry was applied to one side of a current collector. The undercoated current collector was used. The solvent was then evaporated at 65°C, and the current collector was then heated at 75°C. The mixture was evaporated with .

[0356] Next, heat treatment was performed at 250°C under reduced pressure. The pressing was performed at a pressure of 1000 m. By the above steps, an electrode having an active material layer 212 on a current collector was obtained. Formed O.

[0357] <Synthesis of graphene compounds> Next, a graphene compound having the following structural formula (202) was synthesized.

[0358] [ka]

[0359] First, graphene oxide (manufactured by Nishina Materials Co., Ltd., product name: Rap dG Add 0.41 g of O(TQ-11)-1 and 5.6 g (77 mmol) of n-butylamine. This mixture was irradiated with ultrasonic waves for 5 minutes under a nitrogen stream and further stirred at 60°C for 1 hour. After stirring, the mixture was cooled to room temperature, 20 mL of toluene was added, and ultrasonic irradiation was performed for 5 minutes. After cooling the mixture to 0°C, 11 g (3 1 mmol) was added dropwise and stirred at 60°C for 5 hours. After stirring, toluene was added to the mixture. The solid was collected by suction filtration. The solid was then washed with ethanol. The solid was dried and the target black powder (sample 1) was extracted with 0. I got 52g.

[0360] <Formation of Layer 213> First, a method for producing the electrode M will be described. The electrode M is a graphene compound having a thickness of 100 nm and a thickness of 100 nm. First, a layer 213 having a graphene compound is formed on the active material layer 212. 13 was formed. First, a graphene compound and ethanol were mixed to prepare a dispersion. Next, the electrode O having the active material layer 212 on the current collector was placed on a hot plate at 70° C. The prepared dispersion liquid was dropped onto the active material layer 212. Further, a heat treatment was carried out at 70° C. under reduced pressure. Through the above steps, an electrode M having an active material layer 212 and a layer 213 on a current collector was obtained. It was made.

[0361] Next, a method for fabricating the electrode N will be described. The electrode N has graphene oxide on the electrode O. First, graphene oxide and ethanol are mixed to prepare a dispersion. Thereafter, the prepared dispersion liquid was dropped onto the active material layer 212, and a heat treatment was performed, followed by dissolving in ethanol. Through the above steps, the active material layer 212 and the graphene oxide layer were formed on the current collector. The total thickness of the active material layer 212 and the layer 213 was about 9 0 μm.

[0362] Next, the prepared electrodes were punched out to a size of 12 mmφ to form positive electrodes. Two positive electrodes (No. 1 and No. 2) were punched out from each of the plates. A separator is sandwiched between the positive and negative electrodes, and a CR2032 type is inserted. A coin-type storage battery was fabricated. Polypropylene was used as the separator. Ethylene carbonate (EC) and diethyl carbonate (DEC) were mixed in a volume ratio of 1:1. Lithium hexafluorophosphate (LiPF6) was added at 1 mol / L to the mixed solution. The solution was used at a concentration of 100 ml.

[0363] Electrode O, Electrode M and Electrode N Positive Electrode N The amount of the active material (A) and graphene oxide (GTA) on electrodes M and N The amount of the supported graphene compound (GO or GC) is shown in Table 1. The amount of the supported positive electrode active material is 18.6~19.5mg / cm 2 The amount of graphene oxide or graphene compound supported is 1.1~1.8mg / cm 2 It was.

[0364] [Table 1]

[0365] The battery was charged and discharged. The charging was performed at 30 mA / s with a maximum voltage of 4.8 V. The battery was charged at a constant current of 30mA / g (approximately 0.08C). The discharge was performed at a constant current of 30mA / g ( A constant current discharge of approximately 0.08 C was performed.

[0366] FIG. 28 shows the charge-discharge cycle of electrode M, FIG. 29(A) shows the charge-discharge cycle of electrode N, and FIG. 29(B) shows the charge-discharge cycle of electrode O. The characteristics are shown for each electrode condition. Two positive electrodes were punched out for each electrode condition. The results of the power cycle characteristics are shown two for each condition. The vertical axis is the capacity (Capacitance The horizontal axis is the number of cycles. Compared with the condition using electrode O, In the electrode N on which the graphene-containing layer was formed, the decrease in capacity was mitigated. In the electrode M on which a layer having a graphene compound according to one embodiment of the present invention is formed, The decrease in capacity due to the change was small, and good results were obtained. [Explanation of symbols]

[0367] 101 Current collector 102 Active material layer 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 210 electrode 211 Current collector 212 Active material layer 213 layers 220 electrode 221 Active material 230 areas 251 Cation 252 Cation 253 electronic 300 Battery 301 Positive electrode can 302 Anode can 303 Gasket 304 Positive electrode 305 Positive electrode current collector 306 Positive electrode active material layer 307 Negative electrode 308 Negative electrode current collector 309 Negative electrode active material layer 310 Separator 321 Graphene Compounds 331 areas 332 areas 333 areas 500 Battery 501 Positive electrode current collector 502 Positive electrode active material layer 503 Positive electrode 504 Negative electrode current collector 505 Negative electrode active material layer 506 negative electrode 507 Separator 508 Electrolyte 509 Exterior body 510 Positive lead electrode 511 Negative lead electrode 512 Welding Area 514 Sealing part 600 Battery 601 Positive electrode cap 602 Battery Can 603 Positive terminal 604 Positive electrode 605 Separator 606 negative electrode 607 Negative terminal 608 Insulating plate 609 Insulating plate 611 PTC element 612 Safety valve mechanism 900 Circuit Board 910 Label 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 Terminal 951 Terminal 952 Terminal 981 Film 982 Film 990 Battery 991 Exterior body 992 Exterior body 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 devices 7101 Case 7102 Display section 7103 Operation button 7104 Energy storage devices 7200 Portable Information Terminal 7201 Case 7202 Display section 7203 Band 7204 Buckle 7205 Operation button 7206 Input / output terminal 7207 Icon 7300 display device 7304 Display section 7400 Mobile Phone 7401 Case 7402 Display section 7403 Operation button 7404 External connection port 7405 Speaker 7406 Mike 7407 Energy storage devices 7408 Lead electrode 7409 Current collector 8000 display device 8001 Case 8002 Display section 8003 Speaker section 8004 Electricity storage device 8021 Charging device 8022 Cable 8024 Electricity storage device 8100 Lighting equipment 8101 Case 8102 Light source 8103 Energy storage devices 8104 Ceiling 8105 Side wall 8106 Bed 8107 Window 8200 indoor unit 8201 Case 8202 Ventilator 8203 Energy storage devices 8204 Outdoor unit 8300 Electric refrigerator-freezer 8301 Case 8302 Refrigerator door 8303 Freezer door 8304 Energy storage devices 8400 Automobiles 8401 Headlight 8406 Electric Motor 8500 Automobiles 9600 Tablet PC 9625 Switch 9626 Switch 9627 Power Switch 9628 Operation Switch 9629 Fastener 9630 Case 9630a Case 9630b Case 9631 Display section 9631a Display section 9631b Display section 9632a area 9632b area 9633 Solar Cells 9634 Charge / discharge control circuit 9635 Electric storage unit 9636 DC-DC Converter 9637 Converter 9638 Operation key 9639 Button 9640 Moving parts

Claims

1. An electrochemical device comprising: a plurality of active materials; and a graphene compound; the graphene compound has a region provided so as to be attached to surfaces of the plurality of active materials, The graphene compound has a structure represented by the following general formula (G1): 【Chemistry 1】 (In general formula (G1), G layer represents a graphene layer, R 1 represents a substituted or unsubstituted alkylene group, and R 2 represents hydrogen or a substituted or unsubstituted alkyl group.)

2. A plurality of active materials and a graphene compound, the graphene compound has a region provided so as to be attached to surfaces of the plurality of active materials, The graphene compound has a structure represented by the following general formula (G2): 【Chemistry 2】 (In general formula (G2), G layer represents a graphene layer, R 1 represents a substituted or unsubstituted alkylene group, and R 2 represents hydrogen or a substituted or unsubstituted alkyl group.)

3. An electrochemical device comprising: a plurality of active materials; and a graphene compound; the graphene compound has a region provided so as to be attached to surfaces of the plurality of active materials, The graphene compound has a structure represented by the following general formula (G3): 【Chemistry 3】 (In general formula (G3), G layer represents a graphene layer, and R 3 represents a substituted or unsubstituted chain group having at least two ether bonds.)

4. In any one of claims 1 to 3, Each of the active materials has an element A and an element M, The element A is at least one selected from the group 1 elements and the group 2 elements, The element M is at least one selected from manganese and nickel.

5. The battery includes an exterior body, an electrolyte, a separator, a positive electrode, and a negative electrode, An electricity storage device comprising the electrode according to claim 1 as the positive electrode.

6. The battery includes an exterior body, an electrolyte, a separator, a positive electrode, and a negative electrode, A power storage device comprising the electrode according to claim 1 as the negative electrode.

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