Battery

Abstract

To suppress inflation and shrinkage of negative active material particles during charging and discharging when silicone is used as the negative active material particles.SOLUTION: In order to suppress inflation and shrinkage of negative active material particles due to charging and discharging, a negative active martial particle or a plurality of negative active martial particles is constrained or fixed by a graphene compound. In an all-solid-state secondary battery, a boundary between a solid electrolyte and a negative electrode or between the solid electrolyte and a positive electrode has the highest resistance. In order to reduce the interface resistance, at least the negative active material particles are coated with the graphene compound to increase the conductivity, or the cathode active material particles are coated with the graphene compound to increase the conductivity. Since graphene compounds allow carrier ions such as lithium ions pass therethrough, transport of lithium ions between the positive electrode and the negative electrode is not inhibited during charging and discharging.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] One aspect of the present invention relates to an object, a method, or a manufacturing method. Alternatively, the present invention relates to a process, a machine, a manufacture, or a composition of matter. One aspect of the present invention relates to a semiconductor device, a display device, a light-emitting device, a power storage device, a lighting device, or an electronic device, or a manufacturing method thereof. In particular, the present invention relates to an electronic device and an operating system thereof.

[0002] In this specification, the term "electronic device" refers to any device having a power storage device, and includes electro-optical devices having a power storage device, information terminal devices having a power storage device, and the like. [Background technology]

[0003] 2. Description of the Related Art Electronic devices that are carried by users or worn by users have been actively developed.

[0004] Electronic devices carried by users or worn by users operate using primary or secondary batteries, which are examples of power storage devices, as their power source. It is desirable for electronic devices carried by users to be used for long periods of time, and for this reason, large-capacity secondary batteries are used. However, incorporating a large-capacity secondary battery into an electronic device poses the problem of its large size and weight. Therefore, development is underway to develop small or thin, large-capacity secondary batteries that can be incorporated into portable electronic devices.

[0005] Lithium-ion secondary batteries, which use liquids such as organic solvents as a medium for transporting lithium ions, the carrier ions, are widely used. However, secondary batteries using liquids have problems such as electrolyte decomposition reactions depending on the operating temperature range and operating potential, as well as leakage to the outside of the secondary battery. Furthermore, secondary batteries using liquid electrolytes have the risk of fire due to leakage.

[0006] Fuel cells are a type of secondary battery that does not use liquid, but they are devices that use precious metals for the electrodes and the solid electrolyte material is also expensive.

[0007] Furthermore, a power storage device called a solid-state battery that uses a solid electrolyte as a secondary battery that does not use a liquid is known. For example, Patent Document 1 and Patent Document 2 disclose such a device. Patent Document 3 describes using one of a solvent, a gel, or a solid electrolyte as the electrolyte of a lithium-ion secondary battery.

[0008] Patent Document 4 discloses an example in which graphene oxide is used in the positive electrode active material layer of a solid-state battery.

[0009] Furthermore, Patent Document 5 and the like have also been disclosed as solid-state batteries using graphene. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-230889 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-023032 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-229308 [Patent Document 4] Japanese Patent Application Laid-Open No. 2013-229315 [Patent Document 5] JP 2018-98200 A Summary of the Invention [Problem to be solved by the invention]

[0011] To provide an all-solid-state secondary battery that is safer than conventional lithium-ion secondary batteries.

[0012] By using all-solid-state secondary batteries, problems that were previously associated with secondary batteries that used electrolytes, such as electrolyte leakage and deterioration due to changes in the electrolyte, have been resolved, but other problems remain.

[0013] Furthermore, when silicon is used as the negative electrode active material particles of an all-solid-state secondary battery, there is a problem in that the negative electrode active material particles expand and contract due to charging and discharging.

[0014] It has also been found that all-solid-state secondary batteries have the problem of minute short circuits (hereinafter referred to as micro-short circuits). Therefore, one of the challenges is to suppress the occurrence of short circuits or micro-short circuits between the positive and negative electrodes in all-solid-state secondary batteries. [Means for solving the problem]

[0015] In order to solve the above problem, a graphene compound is used to bind or fix a negative electrode active material particle or a plurality of negative electrode active material particles in order to suppress expansion or contraction of the negative electrode active material particles caused by charge and discharge.

[0016] In all-solid-state secondary batteries, the interface between the solid electrolyte and the negative electrode or the interface between the solid electrolyte and the positive electrode has the highest resistance. To reduce this interfacial resistance, at least the negative electrode active material particles are wrapped in a graphene compound to increase conductivity. Alternatively, the positive electrode active material particles are wrapped in a graphene compound to increase conductivity. Because graphene compounds allow carrier ions, such as lithium ions, to pass through, they do not impede the movement of lithium ions between the positive and negative electrodes during charging or discharging.

[0017] Furthermore, by binding or fixing a negative electrode active material particle or a plurality of negative electrode active material particles using a graphene compound, it is possible to inhibit the generation of by-products (precipitates, etc.) and suppress the occurrence of micro-short circuits.

[0018] A micro-short circuit refers to a tiny short circuit inside a secondary battery that does not short the positive and negative electrodes of the secondary battery to the point that charging and discharging is impossible, but rather refers to a phenomenon in which a small amount of short-circuit current flows at the tiny short-circuited part for a period of 10 nanoseconds to less than 1 microsecond. Micro-short circuits are caused by multiple charge and discharge cycles, which result in localized current concentration in parts of the positive electrode and negative electrode due to uneven distribution of positive electrode active material particles, causing parts of the separator to stop functioning or by the generation of by-products (such as precipitates).

[0019] Furthermore, repeated occurrence of micro-short circuits can lead to serious accidents such as abnormal heat generation and fire in the secondary battery.

[0020] Therefore, to prevent local current concentration in a part of the negative electrode and a part of the positive electrode, the surface or inside of the negative electrode is wrapped and fixed with a graphene compound, thereby increasing the conductivity.

[0021] One configuration disclosed in this specification is an all-solid-state battery that includes at least positive electrode active material particles containing carrier ions, a plurality of negative electrode active material particles, a plurality of solid electrolyte particles, and a graphene compound, in which the graphene compound fixes the negative electrode active material particles, and carrier ions pass through the graphene and are taken up into the negative electrode active material particles during charging.

[0022] Another aspect of the present invention is an all-solid-state battery having a plurality of positive electrode active material particles containing carrier ions, a plurality of negative electrode active material particles, a plurality of solid electrolyte particles, and a plurality of graphene compounds, in which one or more negative electrode active material particles are fixed with one or more graphene compounds.

[0023] In this specification, graphene has a carbon hexagonal lattice structure and includes single-layer graphene and multi-layer graphene having 2 to 100 layers. 2A graphene compound refers to a single atomic layer of carbon molecular sheets with bonds. The term "multiple graphenes" refers to multi-layer graphene or multiple single-layer graphenes. Graphene is not limited to being composed solely of carbon; some of the graphene may be bonded to oxygen, hydrogen, or functional groups, making it a graphene compound. Graphene compounds include graphene quantum dots. Graphene compounds can have excellent electrical properties, such as high conductivity, and excellent physical properties, such as high flexibility and high mechanical strength. Graphene compounds also have a planar shape. Graphene compounds enable surface contact with low contact resistance. Even thin graphene compounds can have very high conductivity, allowing efficient formation of conductive paths within the active material layer with a small amount. A spray-drying device can be used to form a graphene compound coating covering the entire surface of the active material. Here, graphene, multi-graphene, graphene quantum dots, or RGO are particularly preferred. RGO refers to a compound obtained by reducing graphene oxide (GO), for example.

[0024] Another aspect of the present invention is an all-solid-state battery having a plurality of positive electrode active material particles containing carrier ions, a plurality of negative electrode active material particles, a plurality of solid electrolyte particles, and a plurality of graphene compounds, in which one or more positive electrode active material particles are fixed with one or more graphene compounds.

[0025] In the above-mentioned configuration, the positive electrode active material particles are preferably an oxide containing lithium and cobalt. The positive electrode active material particles more preferably have a crystal structure represented by the space group R-3m. The positive electrode active material particles preferably have a pseudospinel structure, as described below, particularly when the depth of charge is deep.

[0026] Furthermore, it is preferable that the concentration of halogen such as fluorine in the surface layer of the positive electrode active material particle is higher than the average concentration in the whole particle. The presence of halogen in the surface layer, which is the region in contact with the electrolyte, can effectively improve corrosion resistance against hydrofluoric acid.

[0027] In this way, the surface layer of the positive electrode active material particle preferably has a higher fluorine concentration than the interior and a different composition from the interior. Furthermore, it is preferable that the composition has a stable crystal structure at room temperature. Therefore, the surface layer may have a different crystal structure from the interior. For example, at least a portion of the surface layer of the positive electrode active material particle may have a rock salt crystal structure. Furthermore, when the surface layer and the interior have different crystal structures, it is preferable that the crystal orientations of the surface layer and the interior are roughly the same.

[0028] The surface layer of the positive electrode active material particles must contain at least element M, and in a discharged state, must also contain element A, and must have a path for insertion and desorption of element A. Element A is a metal that serves as a carrier ion. Element A can be, for example, an alkali metal such as lithium, sodium, or potassium, or a Group 2 element such as calcium, beryllium, or magnesium. When sodium is selected, the carrier ion is a sodium ion.

[0029] The element M is, for example, a transition metal. For example, at least one of cobalt, manganese, and nickel can be used as the transition metal. A positive electrode material according to one embodiment of the present invention preferably contains, for example, one or more of cobalt, nickel, and manganese as the element M, and particularly preferably contains cobalt. Furthermore, the position of the element M may contain an element such as aluminum that does not change valence and can have the same valence as the element M, more specifically, a trivalent typical element, for example.

[0030] Alternatively, both the positive electrode active material particles and the negative electrode active material particles may be wrapped in the respective graphene compounds. In this configuration, a plurality of positive electrode active material particles containing carrier ions and a plurality of first solid electrolyte particles are both at least partially or entirely wrapped in the first graphene compound, a plurality of negative electrode active material particles and a plurality of second solid electrolyte particles are both at least partially or entirely wrapped in the second graphene compound, and a third solid electrolyte particle is disposed between the second graphene compound overlapping with the first graphene compound, resulting in an all-solid-state battery.

[0031] Another aspect of the present invention is an all-solid-state battery having a plurality of groups, each group including a plurality of positive electrode active material particles containing carrier ions and a plurality of first solid electrolyte particles wrapped with a first graphene compound, adjacent to each other; a plurality of negative electrode active material particles and a plurality of second solid electrolyte particles wrapped with a second graphene compound; and third solid electrolyte particles between the second graphene compounds overlapping with the groups of first graphene compounds.

[0032] In each of the above configurations, the first, second, and third solid electrolyte particles have the same components. When materials having the same components are used, the manufacturing costs can be reduced because a common material is used. Alternatively, the first, second, and third solid electrolyte particles may each be made of different materials. When different materials are used, a material that is compatible with the positive electrode active material particles is used for the first solid electrolyte particles, and a material that is compatible with the negative electrode active material particles is used for the second solid electrolyte particles. "Compatible" refers to the absence of unwanted by-products when the particles are in contact with each other and are charged and discharged.

[0033] By adopting the above-mentioned configurations, it is possible to prevent the generation of by-products (precipitates, etc.) on the negative electrode, and to suppress the occurrence of micro-short circuits.

[0034] All-solid-state batteries do not use flammable organic solvents inside the battery, which simplifies safety devices and makes them superior in terms of manufacturing costs and productivity.

[0035] Furthermore, graphene or a graphene compound is formed by subjecting graphene oxide to reduction treatment or the like.

[0036] Graphene oxide contains epoxy groups, carbonyl groups, carboxyl groups, hydroxyl groups, etc. In polar solutions, different graphene oxides are less likely to aggregate together because the oxygen in the functional groups is negatively charged. Therefore, graphene oxide is more likely to be uniformly dispersed in polar liquids.

[0037] In each of the above configurations, the solid electrolyte particles may be a sulfide-based solid electrolyte or an oxide-based solid electrolyte.

[0038] Examples of sulfide-based solid electrolytes include lithium composite sulfide materials such as Li2S-SiS2-Li3PO4, Li2S-P2S5, Li2S-SiS2-Ga2S3, LiI-Li2S-P2S5, LiI-Li2S-B2S3, LiI-Li2S-SiS2, Li3PO4-Li2S-SiS2, and Li4SiO4-Li2S-SiS2.

[0039] In addition, oxide-based solid electrolytes include LiPON, Li2O, Li2CO3, Li2MoO4, Li3PO4, Li3VO4, Li4SiO4, LLT(La 2 / 3-x Li 3x TiO3), LLZ(Li7La3Zr2O 12 ) and other lithium composite oxides and lithium oxide materials.

[0040] LLZ is a garnet-type oxide containing Li, La, and Zr, and may be a compound containing Al, Ga, or Ta.

[0041] Alternatively, a polymer solid electrolyte such as PEO (polyethylene oxide) formed by a coating method may be used. Furthermore, a composite solid electrolyte containing the above-mentioned inorganic solid electrolyte and polymer solid electrolyte may be used.

[0042] In this specification, the surface layer of particles of active material or the like refers to the region from the surface to a depth of about 10 nm. Surfaces formed by cracks or fissures may also be considered the surface. The region deeper than the surface layer is called the interior.

[0043] In this specification, the layered rock-salt type crystal structure of a composite oxide containing lithium and a transition metal refers to a crystal structure having a rock-salt type ion arrangement in which cations and anions are alternately arranged, and in which the transition metal and lithium are regularly arranged to form a two-dimensional plane, allowing two-dimensional diffusion of lithium. Defects such as cation or anion deficiencies may also be present. Furthermore, strictly speaking, the layered rock-salt type crystal structure may have a distorted rock-salt type crystal lattice structure.

[0044] In this specification and the like, the rock salt type crystal structure refers to a structure in which cations and anions are arranged alternately, and it is also possible for there to be a deficiency of cations or anions.

[0045] In this specification and the like, the pseudospinel crystal structure of a composite oxide containing lithium and a transition metal refers to a crystal structure that has the space group R-3m and is not a spinel crystal structure, but in which ions of cobalt, magnesium, etc. occupy hexacoordinated oxygen positions and the arrangement of cations has a symmetry similar to that of a spinel structure. Note that in the pseudospinel crystal structure, light elements such as lithium may occupy tetracoordinated oxygen positions, and in this case, the arrangement of ions also has a symmetry similar to that of a spinel structure.

[0046] It can also be said that the pseudospinel crystal structure is similar to the CdCl2 crystal structure, although it has random Li between the layers. This CdCl2-like crystal structure was observed when lithium nickel oxide was charged to a depth of charge of 0.94 (Li 0.06 The crystal structure is similar to that of lithium cobalt oxide (NiO2), but it is known that pure lithium cobaltate or layered rock salt type positive electrode active material particles containing a large amount of cobalt do not usually have this crystal structure.

[0047] The anions in layered rock salt crystals and rock salt crystals have a cubic close-packed structure (face-centered cubic lattice structure). It is presumed that the anions in pseudospinel crystals also have a cubic close-packed structure. When these crystals contact, there are crystal planes where the cubic close-packed structures formed by the anions are aligned. However, the space group of layered rock salt crystals and pseudospinel crystals is R-3m, which is different from the space groups of rock salt crystals, Fm-3m (the space group of general rock salt crystals) and Fd-3m (the space group of rock salt crystals with the simplest symmetry). Therefore, the Miller indices of the crystal planes that satisfy the above conditions are different between layered rock salt crystals and pseudospinel crystals and rock salt crystals. In this specification, when the cubic close-packed structures formed by the anions are aligned in layered rock salt crystals, pseudospinel crystals, and rock salt crystals, the crystal orientations may be said to be approximately aligned.

[0048] The general alignment of the crystal orientations of the two regions can be determined from TEM (transmission electron microscope), STEM (scanning transmission electron microscope), HAADF-STEM (high-angle annular dark-field scanning transmission electron microscope), and ABF-STEM (annular bright-field scanning transmission electron microscope) images. X-ray diffraction (XRD), electron diffraction, and neutron diffraction can also be used. In TEM images, the arrangement of cations and anions can be observed as repeated bright and dark lines. When the orientation of the cubic close-packed structure of the layered rock salt crystal and the rock salt crystal is aligned, the angle between the repeated bright and dark lines between the crystals can be observed to be less than 5 degrees, and more preferably less than 2.5 degrees. Light elements such as oxygen and fluorine may not be clearly visible in TEM images, but in such cases, the alignment of the orientations can be determined from the arrangement of metal elements.

[0049] In this specification, the theoretical capacity of a positive electrode active material refers to the amount of electricity when all of the intercalable lithium contained in the positive electrode active material is deintercalated. For example, the theoretical capacity of LiCoO2 is 274 mAh / g, the theoretical capacity of LiNiO2 is 274 mAh / g, and the theoretical capacity of LiMn2O4 is 148 mAh / g.

[0050] In this specification and the like, the depth of charge when all intercalable and deintercalable lithium is intercalated is defined as 0, and the depth of charge when all intercalable and deintercalable lithium contained in the positive electrode active material is deintercalated is defined as 1.

[0051] In this specification, charging refers to the transfer of lithium ions from the positive electrode to the negative electrode within a battery and the transfer of electrons from the negative electrode to the positive electrode in an external circuit. Regarding a positive electrode active material, charging refers to the removal of lithium ions. A positive electrode active material with a charge depth of 0.7 to 0.9 is sometimes referred to as a positive electrode active material charged at a high voltage.

[0052] Similarly, discharging refers to the transfer of lithium ions from the negative electrode to the positive electrode within the battery and the transfer of electrons from the positive electrode to the negative electrode in an external circuit. For positive electrode active materials, discharging refers to the insertion of lithium ions. A fully discharged positive electrode active material is defined as a positive electrode active material with a charge depth of 0.06 or less, or a positive electrode active material that has been discharged to 90% or more of its charge capacity from a high-voltage charged state. [Effects of the Invention]

[0053] By using a graphene compound to wrap and fix negative electrode active material particles or positive electrode active material particles, stress caused by expansion or contraction of the negative electrode active material particles or positive electrode active material particles can be alleviated, thereby preventing deterioration of characteristics caused by expansion or contraction of the negative electrode active material particles or positive electrode active material particles during charge or discharge. [Brief explanation of the drawings]

[0054] [Figure 1] FIG. 1 is an example of a schematic cross-sectional view of a secondary battery showing one embodiment of the present invention. [Figure 2] FIG. 2 illustrates an example of a negative electrode according to one embodiment of the present invention. [Figure 3] FIG. 3 illustrates an example of a negative electrode according to one embodiment of the present invention. [Figure 4] FIG. 4 illustrates an example of a negative electrode according to one embodiment of the present invention. [Figure 5] FIG. 5A is a perspective view of an all-solid-state battery, and FIG. 5B is a cross-sectional view thereof. [Figure 6] 6A, 6B, 6C, and 6D are perspective views of all-solid-state batteries. [Figure 7] 7A and 7B are perspective views of an all-solid-state battery. [Figure 8] 8A, 8B, and 8C show examples of a vehicle. [Figure 9] 9A, 9B, 9C, 9D, and 9E are perspective views showing examples of electronic devices. [Figure 10] FIG. 10 is a perspective view illustrating an example of a power storage device. [Figure 11] FIG. 11 is a diagram illustrating an example of a method for producing a positive electrode active material. DETAILED DESCRIPTION OF THE INVENTION

[0055] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various modifications can be made to the embodiments and details. Furthermore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0056] (Embodiment 1) This embodiment describes an example of manufacturing an all-solid-state secondary battery that includes a positive electrode, an oxide solid electrolyte, and a negative electrode, and that has reduced graphene oxide attached to and fixed on a surface of the negative electrode, thereby suppressing expansion and contraction due to charge and discharge and improving ionic conductivity.

[0057] FIG. 1 is a conceptual diagram showing the cross-sectional structure of a solid-state battery.

[0058] A plurality of solid electrolyte particles 105 are disposed between a positive electrode current collector 111 and a negative electrode current collector 110. The positive electrode current collector and the negative electrode current collector can be made of a known metal material that can be used in all-solid-state batteries, and are current collectors containing one or more metals selected from Cu, Ni, Al, V, Au, Pt, Mg, Fe, Ti, Cr, Zn, Ge, and In.

[0059] There are two types of solid-state batteries: thin-film all-solid-state batteries and bulk all-solid-state batteries. Thin-film all-solid-state batteries are obtained by stacking thin films, while bulk all-solid-state batteries are obtained by stacking fine particles. Figure 1 shows an example of a bulk all-solid-state battery.

[0060] As shown in FIG. 1, positive electrode active material particles 104 are located near a positive electrode current collector 111, and negative electrode active material particles 103 are located near a negative electrode current collector 110, with solid electrolyte particles 105 arranged to fill the gaps between them.

[0061] The negative electrode active material particles can be made of elements capable of undergoing charge-discharge reactions through alloying and dealloying reactions with lithium. For example, materials containing at least one of silicon, tin, gallium, aluminum, germanium, lead, antimony, bismuth, silver, zinc, cadmium, and indium can be used. These elements have a higher capacity than carbon, and silicon, in particular, has a high theoretical capacity of 4200 mAh / g. For this reason, silicon is preferred for the negative electrode active material particles. Compounds containing these elements may also be used. Examples include SiO, Mg2Si, Mg2Ge, SnO, SnO2, Mg2Sn, SnS2, V2Sn3, FeSn2, CoSn2, Ni3Sn2, Cu6Sn5, Ag3Sn, Ag3Sb, Ni2MnSb, CeSb3, LaSn3, La3Co2Sn7, CoSb3, InSb, and SbSn. Here, elements that can undergo charge-discharge reactions by alloying / dealloying reactions with lithium, and compounds containing such elements, are sometimes called alloy-based materials.

[0062] In this specification and the like, SiO refers to, for example, silicon monoxide. Alternatively, SiO refers to SiO x Here, 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.

[0063] In addition, the negative electrode active material particles are titanium dioxide (TiO2), lithium titanium oxide (Li4Ti5O 12 ), lithium-graphite intercalation compound (Li x C6), niobium pentoxide (Nb2O5), tungsten oxide (WO2), molybdenum oxide (MoO2), and other oxides can be used.

[0064] Furthermore, the first graphene compound 101 is provided so as to wrap around the negative electrode current collector 110 and the plurality of negative electrode active material particles 103. The first graphene compound 101 is used to fix the negative electrode active material particle or the plurality of negative electrode active material particles to the negative electrode current collector 110. Furthermore, by using the first graphene compound 101 to bind or fix the negative electrode active material particle or the plurality of negative electrode active material particles, it is possible to inhibit the generation of by-products (such as precipitates) and suppress the occurrence of micro-short circuits.

[0065] The first graphene compound 101 also encases a plurality of solid electrolyte particles together with a plurality of negative electrode active material particles 103.

[0066] FIG. 1 shows an example in which a layer made of a plurality of solid electrolyte particles 105 is provided between a positive electrode current collector 111 and a negative electrode current collector 110, and the solid electrolyte particles 105 and the solid electrolyte particles wrapped in a first graphene compound 101 are made of the same material.

[0067] Furthermore, a structure including at least the positive electrode current collector 111 and the positive electrode active material particles 104 functions as a positive electrode, and this positive electrode is wrapped with the second graphene compound 102.

[0068] 1 shows an example in which a material having the same components as the solid electrolyte particles 105 and the solid electrolyte particles wrapped by the second graphene compound 102 is used. The distance between the first graphene compound 101 and the second graphene compound 102 is 0.1 μm or more and 1 mm or less, preferably 1 μm or more and 100 μm or less, depending on the material of the solid electrolyte particle 105.

[0069] 2 shows a schematic cross-sectional view of the first graphene compound 101 after wrapping the solid electrolyte particles, the negative electrode active material particles 103, and the negative electrode current collector 110. After obtaining the state shown in FIG. 2, a firing step or a pressing step may be performed.

[0070] After disposing the negative electrode active material particles 103 and the solid electrolyte particles on the negative electrode current collector 110, reduced graphene oxide (RGO) is attached so as to surround the negative electrode current collector 110, the solid electrolyte particles, and the negative electrode active material particles 103.

[0071] A compound obtained by reducing graphene oxide is sometimes called "Reduced Graphene Oxide (RGO)." Note that in RGO, some oxygen or oxygen-containing atomic groups may remain bonded to carbon, rather than all of the oxygen contained in graphene oxide being released. For example, RGO may have functional groups such as epoxy groups, carbonyl groups such as carboxyl groups, or hydroxyl groups. In this specification and elsewhere, a graphene compound may have a graphene precursor. A graphene precursor refers to a substance used to produce graphene, and graphene precursors may include, for example, the aforementioned graphene oxide or graphite oxide. Note that graphene containing alkali metals or graphene containing elements other than carbon, such as oxygen, may be referred to as graphene analogs. In this specification and elsewhere, graphene compounds also include graphene analogs. Graphene compounds include graphene quantum dots.

[0072] Then, the solid electrolyte particles, the positive electrode active material particles 104, and the positive electrode current collector 111 are wrapped in the second graphene compound 102, and then a plurality of solid electrolyte particles 105 are sandwiched between the first graphene compound 101 and the second graphene compound 102 and stacked to produce a solid battery. Therefore, the solid electrolyte particles are added at different times during production. Depending on the negative electrode active material, positive electrode active material, and production process used, even if the same material is used for the solid electrolyte particles, some of them may be altered. In Figure 1, each solid electrolyte particle is illustrated as being identical.

[0073] In practice, a plurality of types of particles may be filled between the positive electrode current collector 111 and the negative electrode current collector 110 by pressing to eliminate voids as much as possible.

[0074] At this stage, the laminate shown in Figure 1 is obtained. To bond the laminate, heat treatment and pressing are performed on the laminate to improve density. Heating may also be performed simultaneously with the pressing process.

[0075] The resulting laminate is then housed in an exterior body such as a laminate film or a metal can, thereby completing the production of an all-solid-state battery.

[0076] (Embodiment 2) In this embodiment, an example that is partially different from the first embodiment will be described below with reference to FIG.

[0077] 3 shows an example in which the current collector is not wrapped with a graphene compound. In FIG. 3, the solid electrolyte particles and the negative electrode active material particles 103 are wrapped with the first graphene compound 101 so as to surround them.

[0078] By combining and stacking the positive electrode shown in Embodiment 1, an all-solid-state battery can be manufactured.

[0079] Alternatively, a positive electrode may be formed without wrapping a positive electrode current collector with the second graphene compound 102, and then stacked on the negative electrode shown in FIG. 2 to form an all-solid-state battery.

[0080] This embodiment mode can be freely combined with Embodiment Mode 1.

[0081] (Embodiment 3) In this embodiment, an example that is partially different from the first embodiment will be described below with reference to FIG.

[0082] 4 shows a configuration in which a plurality of groups wrapped with the first graphene, specifically, solid electrolyte particles and negative electrode active material particles 103, are wrapped with the first graphene compound 101. Seven groups are shown in FIG. 4. Solid electrolyte particles are disposed in the gaps between the groups.

[0083] The negative electrode shown in FIG. 4 and the positive electrode shown in Embodiment 1 are combined and stacked to form an all-solid-state battery.

[0084] Furthermore, similarly to the negative electrode shown in FIG. 4, a positive electrode may be formed by constituting a plurality of groups of the second graphene compound 102, and then stacked on the negative electrode shown in FIG. 4 to fabricate an all-solid-state battery.

[0085] Alternatively, a positive electrode may be formed without wrapping a positive electrode current collector with the second graphene compound 102, and then stacked on the negative electrode shown in FIG. 4 to form an all-solid-state battery.

[0086] This embodiment mode can be freely combined with Embodiment Mode 1 or 2.

[0087] For example, an all-solid-state battery may be fabricated by combining the positive electrode wrapped using the graphene compound shown in FIG. 3 with the negative electrode shown in FIG. 4 of this embodiment.

[0088] (Fourth embodiment) In this embodiment, an example of a method for manufacturing a positive electrode will be described.

[0089] An example of a method for manufacturing a positive electrode active material will be described with reference to FIG.

[0090] As shown in step S11 of Figure 11, first, lithium fluoride, which is a fluorine source, and magnesium fluoride, which is a magnesium source, are prepared as materials for the mixture 902. Among these, lithium fluoride is preferable because it has a relatively low melting point of 848°C and is easily melted in the annealing step described below. Lithium fluoride can be used as both a lithium source and a fluorine source. Magnesium fluoride can also be used as both a fluorine source and a magnesium source.

[0091] In this embodiment, lithium fluoride LiF is prepared as the fluorine source and lithium source, and magnesium fluoride MgF2 is prepared as the fluorine source and magnesium source (Step S11 in FIG. 11). The molar ratio of lithium fluoride LiF to magnesium fluoride MgF2 is preferably LiF:MgF2=x:1 (0≦x≦1.9), more preferably LiF:MgF2=x:1 (0.1≦x≦0.5), and even more preferably LiF:MgF2=x:1 (x=nearly 0.33).

[0092] If the subsequent mixing and grinding steps are performed wet, a solvent is prepared. Examples of solvents that can be used include ketones such as acetone, alcohols such as ethanol and isopropanol, ether, dioxane, acetonitrile, and N-methyl-2-pyrrolidone (NMP). It is more preferable to use an aprotic solvent that is less likely to react with lithium. In this embodiment, acetone is used (see step S11 in FIG. 11).

[0093] Next, the materials for the mixture 902 are mixed and pulverized (step S12 in FIG. 11). Mixing can be performed by either a dry or wet method, but a wet method is preferred because it allows for finer pulverization. For example, a ball mill, a bead mill, or the like can be used for mixing. When using a ball mill, it is preferable to use zirconia balls as the medium. It is preferable to thoroughly perform this mixing and pulverization process to finely pulverize the mixture 902.

[0094] The mixed and crushed materials are collected (step S13 in FIG. 11) to obtain a mixture 902 (step S14 in FIG. 11).

[0095] The D50 of the mixture 902 is preferably, for example, 600 nm or more and 20 μm or less, and more preferably 1 μm or more and 10 μm or less. Such a finely pulverized mixture 902 facilitates uniform adhesion of the mixture 902 to the surface of the composite oxide particles when mixed with a composite oxide containing lithium, a transition metal, and oxygen in a subsequent process. Uniform adhesion of the mixture 902 to the surface of the composite oxide particles is preferable because it facilitates thorough distribution of halogen and magnesium throughout the surface layer of the composite oxide particles after heating. If there are regions in the surface layer that do not contain halogen and magnesium, it may be difficult to form the pseudospinel crystal structure described above in a charged state.

[0096] Next, a lithium source is prepared as shown in step S25. In step S25, a composite oxide containing lithium, a transition metal, and oxygen that has been synthesized in advance is used.

[0097] For example, lithium cobalt oxide particles (product name: Cellseed C-10N) manufactured by Nippon Chemical Industry Co., Ltd. can be used as pre-synthesized lithium cobalt oxide. This lithium cobalt oxide has an average particle size (D50) of approximately 12 μm, and impurity analysis by glow discharge mass spectrometry (GD-MS) shows that the magnesium and fluorine concentrations are 50 ppm wt or less, the calcium, aluminum, and silicon concentrations are 100 ppm wt or less, the nickel concentration is 150 ppm wt or less, the sulfur concentration is 500 ppm wt or less, the arsenic concentration is 1100 ppm wt or less, and the concentrations of other elements other than lithium, cobalt, and oxygen are 150 ppm wt or less.

[0098] The composite oxide containing lithium, a transition metal, and oxygen in step S25 preferably has a layered rock-salt crystal structure with few defects and strain. Therefore, a composite oxide with few impurities is preferred. If the composite oxide containing lithium, a transition metal, and oxygen contains a large amount of impurities, it is likely to have a crystal structure with many defects or strains.

[0099] Next, the mixture 902 is mixed with a composite oxide containing lithium, a transition metal, and oxygen (step S31 in FIG. 11). The ratio of the number of transition metal atoms TM in the composite oxide containing lithium, a transition metal, and oxygen to the number of magnesium atoms MgMix1 in the mixture 902 is preferably TM:MgMix1=1:y (0.005≦y≦0.05), more preferably TM:MgMix1=1:y (0.007≦y≦0.04), and even more preferably about TM:MgMix1=1:0.02.

[0100] The mixing conditions in step S31 are preferably milder than those in step S12 so as not to destroy the composite oxide particles. For example, the mixing conditions are preferably lower in rotation speed or shorter in time than those in step S12. It can also be said that dry mixing conditions are milder than wet mixing. For example, a ball mill, bead mill, etc. can be used for mixing. When using a ball mill, it is preferable to use zirconia balls as the media.

[0101] The mixed materials are collected (step S32 in FIG. 11) to obtain a mixture 903 (step S33 in FIG. 11).

[0102] Next, the mixture 903 is heated. This step is sometimes called annealing or second heating to distinguish it from the previous heating step.

[0103] The annealing is preferably performed at an appropriate temperature and time. The appropriate temperature and time vary depending on conditions such as the size and composition of the composite oxide particles containing lithium, transition metal, and oxygen in step S25. If the particles are small, a lower temperature or shorter time may be more preferable than if the particles are large.

[0104] For example, when the average particle size (D50) of the particles in step S25 is about 12 μm, the annealing temperature is preferably, for example, 600° C. or more and 950° C. or less. The annealing time is, for example, preferably 3 hours or more, more preferably 10 hours or more, and even more preferably 60 hours or more.

[0105] On the other hand, when the average particle size (D50) of the particles in step S25 is about 5 μm, the annealing temperature is preferably, for example, 600° C. to 950° C. The annealing time is preferably, for example, 1 hour to 10 hours, more preferably about 2 hours.

[0106] The temperature drop time after annealing is preferably, for example, 10 hours or more and 50 hours or less.

[0107] When the mixture 903 is annealed, it is believed that the material with the lowest melting point (e.g., lithium fluoride, melting point 848°C) melts first and distributes to the surface layer of the composite oxide particles. Next, the presence of this molten material lowers the melting points of the other materials, which then melts them. For example, magnesium fluoride (melting point 1263°C) melts and distributes to the surface layer of the composite oxide particles.

[0108] The diffusion of elements contained in this mixture 903 is faster in the surface layer and near the grain boundaries than inside the composite oxide particles. Therefore, magnesium and halogens are concentrated at higher concentrations in the surface layer and near the grain boundaries than inside. As will be described later, a high magnesium concentration in the surface layer and near the grain boundaries can more effectively suppress changes in the crystal structure.

[0109] The annealed material is collected (step S35 in FIG. 11) to obtain a mixture 904 (step S36 in FIG. 11).

[0110] Next, as shown in step S50, the mixture 904 and the finely powdered nickel hydroxide are mixed. Then, the mixed material is recovered (step S51). The finely powdered nickel hydroxide is previously subjected to step S15 in which nickel hydroxide is mixed with acetone and step S16 in which it is recovered. By step S16, finely powdered nickel hydroxide is obtained (step S17).

[0111] The materials mixed in step S50 are collected in step S51 to obtain a mixture 905 (step S52 in FIG. 11).

[0112] Next, through steps S53 to S55, the metal Z is added to the positive electrode active material. The metal Z can be added by, for example, a liquid phase method such as a sol-gel method, a solid phase method, a sputtering method, a vapor deposition method, a CVD (chemical vapor deposition) method, a PLD (pulsed laser deposition) method, or the like.

[0113] As shown in FIG. 11 , first, in step S52, a metal source is prepared. Furthermore, when a sol-gel method is used, a solvent to be used in the sol-gel method is prepared. Examples of the metal source that can be used include metal alkoxides, metal hydroxides, and metal oxides. When the metal Z is aluminum, for example, the number of cobalt atoms in the lithium cobalt oxide is 1, and the aluminum concentration in the metal source is 0.001 to 0.02 times. When the metal Z is nickel, for example, the number of cobalt atoms in the lithium cobalt oxide is 1, and the nickel concentration in the metal source is 0.001 to 0.02 times. When the metal Z is aluminum and nickel, for example, the number of cobalt atoms in the lithium cobalt oxide is 1, and the aluminum concentration in the metal source is 0.001 to 0.02 times, and the nickel concentration in the metal source is 0.001 to 0.02 times.

[0114] Here, as an example, a sol-gel method is applied, and an example is shown in which aluminum isopropoxide is used as the metal source and isopropanol is used as the solvent.

[0115] Next, aluminum alkoxide is dissolved in alcohol, and lithium cobalt oxide particles are further mixed therein (Step S53 in FIG. 11).

[0116] The amount of metal alkoxide required varies depending on the particle size of the lithium cobalt oxide. For example, when aluminum isopropoxide is used and the particle size (D50) of the lithium cobalt oxide is about 20 μm, it is preferable to add aluminum isopropoxide so that the concentration of aluminum in the lithium cobalt oxide is 0.001 to 0.02 times the number of cobalt atoms in the lithium cobalt oxide.

[0117] Next, the mixture of the alcohol solution of the metal alkoxide and the lithium cobalt oxide particles is stirred in an atmosphere containing water vapor. Stirring can be performed, for example, using a magnetic stirrer. The stirring time is sufficient to cause hydrolysis and polycondensation reactions between the water and metal alkoxide in the atmosphere, and can be performed, for example, for 4 hours at 25°C and 90% RH (relative humidity). Stirring can also be performed in an atmosphere without humidity or temperature control, such as in the air inside a draft chamber. In such cases, a longer stirring time is preferable, for example, 12 hours or more at room temperature.

[0118] By reacting water vapor in the atmosphere with metal alkoxide, the sol-gel reaction can proceed more slowly than when liquid water is added. Also, by reacting metal alkoxide with water at room temperature, the sol-gel reaction can proceed more slowly than when, for example, heating is performed at a temperature above the boiling point of the solvent alcohol. By proceeding with the sol-gel reaction slowly, a high-quality coating layer with a uniform thickness can be formed.

[0119] A precipitate is recovered from the mixed solution after the above treatment (step S54 in FIG. 11). Recovery methods that can be used include filtration, centrifugation, and evaporation to dryness. The precipitate can be washed with the same alcohol as the solvent in which the metal alkoxide was dissolved. When evaporation to dryness is used, it is not necessary to separate the solvent and the precipitate in this step; for example, the precipitate can be recovered in the drying process of the next step (step S54).

[0120] Next, the collected residue is dried to obtain a mixture (Step S54 in FIG. 11). The drying step can be performed, for example, by vacuum or forced air drying at 80° C. for 1 hour to 4 hours.

[0121] Next, the resulting mixture is heated (step S55 in FIG. 11).

[0122] The heating time is preferably set to a holding time within the heating temperature range of 1 hour to 80 hours.

[0123] The heating temperature is less than 1000°C, preferably 700°C or higher and 950°C or lower, and more preferably about 850°C.

[0124] The heating is preferably carried out in an atmosphere containing oxygen.

[0125] In this embodiment, the heating temperature is set to 850° C. and is maintained for two hours, the temperature is increased at 200° C. / h, and the oxygen flow rate is set to 10 L / min.

[0126] The heating temperature in step S55 is preferably lower than the heating temperature in step S34.

[0127] <Steps S56 and S57> Next, the cooled particles are collected (Step S56 in FIG. 11). Furthermore, it is preferable to sieve the particles. Through the above process, a mixture 906 that can be used as a positive electrode active material can be produced (Step S57 in FIG. 11).

[0128] Any of the mixtures 902, 903, 904, 905, and 906 obtained by the above manufacturing process can be used as a positive electrode active material.

[0129] The mixture 902 is a positive electrode active material having a lithium component, a magnesium component, and a fluorine component, and the mixtures 903 and 904 are positive electrode active materials having a lithium component, a cobalt component, a magnesium component, and a fluorine component.

[0130] Furthermore, mixture 905 is a positive electrode active material having a lithium component, a cobalt component, a magnesium component, a nickel component, and a fluorine component, and mixture 906 is a positive electrode active material having a lithium component, a cobalt component, a magnesium component, a nickel component, an aluminum component, and a fluorine component.

[0131] A slurry is prepared by dispersing graphene oxide in a solvent, and a plurality of positive electrode active material particles prepared using any one of the mixtures 902, 903, 904, 905, and 906 are placed on a positive electrode current collector. The slurry is applied to cover the positive electrode active material particles and dried. After that, reduction treatment is performed to attach graphene to the surface of the positive electrode active material.

[0132] This embodiment mode can be freely combined with other embodiment modes.

[0133] For example, by combining this with the first embodiment, a solid-state battery can be produced.

[0134] (Embodiment 5) 1 shown in Embodiment 1 is a conceptual diagram illustrating a cross-sectional structure of a solid-state battery, in which solid electrolyte particles 105 are disposed between a positive electrode current collector 111 and a negative electrode current collector 110. The wrapping method of the first graphene compound 101 can be selected from any one of FIGS. 2, 3, and 4.

[0135] As a sealing container for the all-solid-state battery, it is preferable to use a package with excellent airtightness, such as a ceramic package or a resin package. Furthermore, when sealing, it is preferable to block the outside air and perform the sealing in a sealed atmosphere, for example, in a glove box.

[0136] 5A shows a perspective view of an all-solid-state secondary battery that has external electrodes 71 and 72 and is sealed in a package member. Such an all-solid-state secondary battery can be directly mounted on a circuit board or the like.

[0137] 5B shows an example of a cross section taken along the dotted line in FIG. 5A. The stack is surrounded and sealed by package member 70a, which is a flat plate with electrode layer 73a, frame-shaped package member 70b, and package member 70c, which is a flat plate with electrode layer 73b. Package members 70a, 70b, and 70c can be made of an insulating material, such as a resin material or ceramic.

[0138] The external electrode 71 is electrically connected to the positive electrode layer 50a via the electrode layer 73a and functions as a positive electrode, while the external electrode 72 is electrically connected to the negative electrode layer 50c via the electrode layer 73b and functions as a negative electrode.

[0139] Although FIG. 5B shows an example in which the positive electrode layer 50a, the solid electrolyte layer 50b, and the negative electrode layer 50c are stacked as one set, a plurality of sets may be stacked.

[0140] 6A, 6B, 6C, and 6D show examples of fabricating laminated secondary batteries using a packaging method different from that shown in FIG. 5A.

[0141] FIG. 6A shows an external view of a positive electrode 503 and a negative electrode 506. The positive electrode 503 has a positive electrode current collector 501, and a positive electrode active material layer 502 is formed on the surface of the positive electrode current collector 501. The positive electrode 503 also has a region where the positive electrode current collector 501 is partially exposed (hereinafter referred to as a tab region). The negative electrode 506 has a negative electrode current collector 504, and a negative electrode active material layer 505 is formed on the surface of the negative electrode current collector 504. The negative electrode 506 also has a region where the negative electrode current collector 504 is partially exposed, i.e., a tab region. The area and shape of the tab regions of the positive electrode and negative electrode are not limited to the example shown in FIG. 6A.

[0142] First, the negative electrode 506, the solid electrolyte layer 507, and the positive electrode 503 are stacked. FIG. 6B shows the stacked negative electrode 506, the solid electrolyte layer 507, and the positive electrode 503. Here, an example is shown in which five pairs of negative electrodes and four pairs of positive electrodes are used. Next, the tab regions of the positive electrodes 503 are joined together, and a positive electrode lead electrode 510 is joined to the tab region of the outermost positive electrode. For example, ultrasonic welding or the like may be used for joining. Similarly, the tab regions of the negative electrode 506 are joined together, and a negative electrode lead electrode 511 is joined to the tab region of the outermost negative electrode.

[0143] Next, the negative electrode 506, the solid electrolyte layer 507, and the positive electrode 503 are disposed on the outer casing 509. The solid electrolyte layer 507 may be any material layer (such as ceramic) containing a solid component capable of conducting lithium ions. For example, the solid electrolyte layer 507 may be formed by forming a sheet from a slurry of ceramic powder or glass powder. Ceramics are defined as inorganic compounds, such as oxides, carbides, nitrides, and borides, regardless of whether they are metallic or nonmetallic. Glass is defined as an amorphous material exhibiting a glass transition phenomenon, but microcrystalline glass is sometimes called ceramic glass. Because ceramic glass has crystallinity, it can be confirmed by X-ray diffraction. Examples of solid electrolytes that can be used include oxide solid electrolytes and sulfide solid electrolytes. The positive electrode active material layer 502 and the negative electrode active material layer 505 also contain a solid electrolyte and may also contain a conductive additive. The conductive additive may be any material with electronic conductivity, such as a carbon material or a metal material.

[0144] Examples of oxide solid electrolytes that can be used as positive electrode active material particles include Li3PO4, Li3BO3, Li4SiO4, Li4GeO4, LiNbO3, LiVO2, LiTiO3, and LiZrO3. Composite compounds of these can also be used, such as Li3BO3-Li4SiO4. The surface of the solid electrolyte can be at least partially covered with a coating layer having a thickness of 1 nm to 20 nm, and the coating layer can be made of a Li-ion conductive oxide.

[0145] The oxide solid electrolytes used as negative electrode active material particles include Nb2O5, Li4Ti5O 12 In this specification, SiO refers to, for example, silicon monoxide. Alternatively, SiO refers to a material having a higher silicon content than SiO2, and SiO x Here, 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.

[0146] The sulfide solid electrolyte used as the positive electrode active material particles is a material containing Li and S, specifically Li7P3S 11 , Li2S-SiS2, Li2S-P2S5, etc.

[0147] Next, as shown in FIG. 6C, exterior body 509 is folded at the portion indicated by the dashed line. Thereafter, the outer periphery of exterior body 509 is joined. Exterior body 509 is a laminate film formed by laminating a metal foil and an organic resin film, such as aluminum foil or stainless steel foil, and joining can be performed by, for example, thermocompression bonding. In this manner, laminate-type secondary battery 500 shown in FIG. 6D can be produced. Also, although an example in which one laminate film is used for joining is shown here, a configuration in which two laminate films are overlapped and sealed by adhering their peripheral edges may also be used.

[0148] A plurality of laminated secondary batteries 500 can be mounted as one battery module in an electric vehicle or the like.

[0149] 7A is a perspective view showing how three laminated secondary batteries 500 are sandwiched and fixed between a first plate 521 and a second plate 524. As shown in FIG. 7B, the three secondary batteries 500 can be pressurized by fixing the distance between the first plate 521 and the second plate 524 using fixing fixtures 525a and 525b.

[0150] 7A and 7B show an example in which three laminated secondary batteries 500 are used, but this is not particularly limited, and four or more secondary batteries 500 can be used. If ten or more secondary batteries are used, the battery can be used as a power source for a small vehicle, and if 100 or more secondary batteries are used, the battery can be used as a large in-vehicle power source. Furthermore, a protection circuit to prevent overcharging and a temperature sensor to monitor temperature rise may be provided in the laminated secondary battery 500. The shape of the secondary battery is not limited to the laminated type, and may be a coin type, a cylindrical type, a square type, or the like.

[0151] In an all-solid-state battery, applying a predetermined pressure in the stacking direction of the stacked positive and negative electrodes can maintain good contact at the internal interfaces. Applying a predetermined pressure in the stacking direction of the positive and negative electrodes can suppress expansion in the stacking direction due to charging and discharging of the all-solid-state battery, thereby improving the reliability of the all-solid-state battery.

[0152] (Embodiment 6) In this embodiment, an example in which an all-solid-state secondary battery according to one embodiment of the present invention is mounted on a vehicle, such as an automobile, a motorcycle, or a bicycle, is described.

[0153] By installing all-solid-state secondary batteries in vehicles, next-generation clean energy vehicles such as hybrid electric vehicles (HEVs), electric vehicles (EVs), and plug-in hybrid electric vehicles (PHEVs) can be realized.

[0154] FIG. 8 illustrates an example of a vehicle using an all-solid-state secondary battery according to one embodiment of the present invention. An automobile 8400 shown in FIG. 8A is an electric automobile using an electric motor as a power source for traveling. Alternatively, it is a hybrid automobile that can appropriately select and use an electric motor or an engine as a power source for traveling. The automobile 8400 includes a power storage system including an all-solid-state secondary battery 8404. The all-solid-state secondary battery 8404 not only drives the electric motor 8406 but also supplies power to light-emitting devices such as headlights 8401 and interior lights (not shown). To prevent hazard lights from turning off due to a power supply stop caused by an abnormality in the all-solid-state secondary battery 8404, the vehicle preferably includes a secondary battery separate from the one used for driving the vehicle.

[0155] The all-solid-state secondary battery 8404 can also supply power to display devices such as a speedometer and a tachometer included in the automobile 8400. The all-solid-state secondary battery 8404 can also supply power to a navigation system included in the automobile 8400.

[0156] The automobile 8500 shown in FIG. 8B can charge the all-solid-state secondary battery of the automobile 8500 by receiving power supply from an external charging facility using a plug-in system, a contactless power supply system, or the like. FIG. 8B shows a state in which an all-solid-state secondary battery 8024 mounted on the automobile 8500 is being charged via a cable 8022 from a ground-mounted charging device 8021. The charging method and connector specifications may be appropriately determined using a predetermined system such as CHAdeMO (registered trademark) or Combo. The charging device 8021 may be a charging station installed in a commercial facility or a household power source. For example, plug-in technology can be used to charge the all-solid-state secondary battery 8024 mounted on the automobile 8500 using external power supply. Charging can be performed by converting AC power to DC power via a converter such as an AC-DC converter. The all-solid-state secondary battery described in Embodiment 2 is used as the all-solid-state secondary battery 8024.

[0157] Furthermore, although not shown, a power receiving device can be mounted on a vehicle and power can be supplied contactlessly from a ground power transmitting device to charge the vehicle. In the case of this contactless power supply method, by incorporating a power transmitting device into a road or an exterior wall, charging can be performed not only while the vehicle is stopped but also while the vehicle is moving. This contactless power supply method can also be used to transmit and receive power between vehicles. Furthermore, solar cells can be installed on the exterior of the vehicle to charge the all-solid-state secondary battery while the vehicle is stopped or moving. For such contactless power supply, an electromagnetic induction method or a magnetic field resonance method can be used.

[0158] 8C shows an example of a two-wheeled vehicle using an all-solid-state secondary battery of one embodiment of the present invention. A scooter 8600 shown in FIG. 8C includes an all-solid-state secondary battery 8602, a side mirror 8601, and a turn signal light 8603. The all-solid-state secondary battery 8602 can supply electricity to the turn signal light 8603.

[0159] 8C can store an all-solid-state secondary battery 8602 in under-seat storage 8604. The all-solid-state secondary battery 8602 can be stored in under-seat storage 8604 even if under-seat storage 8604 is small.

[0160] This embodiment mode can be combined with the descriptions of other embodiment modes as appropriate.

[0161] (Embodiment 7) In this embodiment, an example in which the solid-state battery described in the previous embodiment is mounted in an electronic device will be described with reference to FIGS.

[0162] First, an example in which a solid-state battery according to one embodiment of the present invention is mounted on a small electronic device will be described with reference to FIGS. 9A to 9C.

[0163] 9A shows an example of a mobile phone. Mobile phone 2100 includes a display unit 2102 built into housing 2101, as well as operation buttons 2103, an external connection port 2104, a speaker 2105, a microphone 2106, and the like. Mobile phone 2100 also includes solid-state battery 2107. Solid-state battery 2107 is manufactured by combining any of the above-described embodiments 1 to 5, and is a highly reliable solid-state battery that suppresses the occurrence of micro-short circuits.

[0164] The mobile phone 2100 can execute various applications such as mobile phone calls, e-mail, document browsing and creation, music playback, internet communication, and computer games.

[0165] The operation button 2103 can be provided with various functions, such as time setting, power on / off operation, wireless communication on / off operation, silent mode activation / deactivation, power saving mode activation / deactivation, etc. For example, the functions of the operation button 2103 can be freely set by an operating system built into the mobile phone 2100.

[0166] The mobile phone 2100 is also capable of performing standardized short-range wireless communication, and can also make hands-free calls by communicating with a wirelessly enabled headset, for example.

[0167] The mobile phone 2100 also has an external connection port 2104, which allows direct data exchange with other information terminals via a connector. Charging can also be performed via the external connection port 2104. Charging may also be performed by wireless power supply without using the external connection port 2104.

[0168] The mobile phone 2100 preferably has a sensor, such as a fingerprint sensor, a pulse sensor, a body temperature sensor, or other human body sensor, a touch sensor, a pressure sensor, or an acceleration sensor.

[0169] FIG. 9B is a perspective view of a device also known as a tobacco-containing smoking device (electronic cigarette). In FIG. 9B, electronic cigarette 2200 includes heating element 2201 and solid-state battery 2204 that supplies power to heating element 2201. When stick 2202 is inserted into electronic cigarette 2200, stick 2202 is heated by heating element 2201. To enhance safety, a protection circuit that prevents overcharging and over-discharging of the solid-state battery may be electrically connected to solid-state battery 2204. Solid-state battery 2204 shown in FIG. 9B has external terminals that allow connection to a charging device. Because solid-state battery 2204 forms the tip when held, it is desirable that the total length be short and the weight be light. Because the solid-state battery of one embodiment of the present invention is highly safe, it is possible to provide a compact and lightweight electronic cigarette 2200 that can be used safely for long periods of time.

[0170] 9C shows an unmanned aerial vehicle 2300 having multiple rotors 2302. The unmanned aerial vehicle 2300 includes a solid-state battery 2301 according to one embodiment of the present invention, a camera 2303, and an antenna (not shown). The unmanned aerial vehicle 2300 can be remotely controlled via the antenna. The solid-state battery according to one embodiment of the present invention is highly safe and can be used safely for a long period of time, making it suitable as a solid-state battery to be mounted on the unmanned aerial vehicle 2300.

[0171] Next, an example in which the solid-state battery according to one embodiment of the present invention is mounted on a vehicle will be described with reference to FIGS. 9D and 9E.

[0172] 9D shows an electric motorcycle 2400 using a solid-state battery according to one embodiment of the present invention. The electric motorcycle 2400 includes a solid-state battery 2401 according to one embodiment of the present invention, a display unit 2402, and a handlebar 2403. The solid-state battery 2401 can supply electricity to a motor that serves as a power source. The display unit 2402 can display the remaining charge of the solid-state battery 2401, the speed of the electric motorcycle 2400, its horizontal state, and the like.

[0173] 9E shows an example of an electric bicycle using the solid-state battery of one embodiment of the present invention. The electric bicycle 2500 includes a battery pack 2502. The battery pack 2502 includes the solid-state battery of one embodiment of the present invention.

[0174] Battery pack 2502 can supply electricity to a motor that assists the rider. Battery pack 2502 can be detached from electric bicycle 2500 and carried around. Battery pack 2502 and electric bicycle 2500 may also have a display unit that can display the remaining battery power, etc.

[0175] 10 includes a power storage system 2612 including a solid-state battery which is one embodiment of the present invention, and a solar panel 2610. The power storage system 2612 is electrically connected to the solar panel 2610 via wiring 2611 or the like. The power storage system 2612 may also be electrically connected to a ground-mounted charging device 2604. The power obtained by the solar panel 2610 can be charged to the power storage system 2612. The power stored in the power storage system 2612 can be charged to a solid-state battery 2602 included in a vehicle 2603 via the charging device 2604.

[0176] The power stored in the power storage system 2612 can also be supplied to other electronic devices in the house. Therefore, even when power cannot be supplied from a commercial power source due to a power outage or the like, the power storage system 2612 of one embodiment of the present invention can be used as an uninterruptible power supply, enabling the use of electronic devices.

[0177] This embodiment mode can be implemented in appropriate combination with other embodiment modes. [Explanation of symbols]

[0178] 50a: positive electrode layer, 50b: solid electrolyte layer, 50c: negative electrode layer, 70a: packaging member, 70b: packaging member, 70c: packaging member, 71: external electrode, 72: external electrode, 73a: electrode layer, 73b: electrode layer, 101: first graphene compound, 102: second graphene compound, 103: negative electrode active material particles, 104: positive electrode active material particles, 105: solid electrolyte particles, 110: negative electrode current collector, 111: positive electrode current collector, 500: secondary 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: solid electrolyte layer, 509: exterior body, 510: positive electrode lead electrode, 511: negative electrode lead electrode, 521: plate, 524: plate, 525a: fixing device, 525b: fixing device, 902: mixture, 903: mixture, 904: mixture, 905: mixture, 906: mixture, 2100: mobile phone, 2101: housing, 2102: display unit, 2 103: operation button, 2104: external connection port, 2105: speaker, 2106: microphone, 2107: solid-state battery, 2200: electronic cigarette, 2201: heating element, 2202: stick, 2204: solid-state battery, 2300: unmanned aerial vehicle, 2301: solid-state battery, 2302: rotor, 2303: camera, 2400: electric two-wheeler, 2401: solid-state battery, 2402: display unit, 2403: handle, 2500: electric bicycle, 2502: battery pack, 2602 : Solid-state battery, 2603: Vehicle, 2604: Charging device, 2610: Solar panel, 2611: Wiring, 2612: Energy storage system, 8021: Charging device, 8022: Cable, 8024: All-solid-state secondary battery, 8400: Automobile, 8401: Headlight, 8404: All-solid-state secondary battery, 8406: Electric motor, 8500: Automobile, 8600: Scooter, 8601: Side mirror, 8602: All-solid-state secondary battery, 8603: Turn signal light, 8604: Under-seat storage

Claims

1. having a positive electrode and a negative electrode, the positive electrode includes a plurality of first groups each including a plurality of positive electrode active material particles, a plurality of first solid electrolyte particles, and a first graphene compound that wraps the plurality of positive electrode active material particles and the plurality of first solid electrolyte particles; the negative electrode includes a plurality of negative electrode active material particles, a plurality of second solid electrolyte particles, and a second graphene compound that wraps the plurality of negative electrode active material particles and the plurality of second solid electrolyte particles; The battery further comprises third solid electrolyte particles positioned between the positive electrode and the negative electrode.

2. having a positive electrode and a negative electrode, the positive electrode includes a plurality of first groups each including a plurality of positive electrode active material particles, a plurality of first solid electrolyte particles, and a first graphene compound that wraps the plurality of positive electrode active material particles and the plurality of first solid electrolyte particles; the negative electrode includes a plurality of second groups each including a plurality of negative electrode active material particles, a plurality of second solid electrolyte particles, and a second graphene compound that wraps around the plurality of negative electrode active material particles and the plurality of second solid electrolyte particles; The battery further comprises third solid electrolyte particles positioned between the positive electrode and the negative electrode.

3. having a positive electrode and a negative electrode, the positive electrode includes a plurality of positive electrode active material particles, a plurality of first solid electrolyte particles, and a first graphene compound that wraps the plurality of positive electrode active material particles and the plurality of first solid electrolyte particles; the negative electrode includes a plurality of second groups each including a plurality of negative electrode active material particles, a plurality of second solid electrolyte particles, and a second graphene compound that wraps around the plurality of negative electrode active material particles and the plurality of second solid electrolyte particles; The battery further comprises third solid electrolyte particles positioned between the positive electrode and the negative electrode.

4. having a positive electrode and a negative electrode, the positive electrode includes a positive electrode current collector, a plurality of positive electrode active material particles, a plurality of first solid electrolyte particles, and a first graphene compound that wraps around the positive electrode current collector, the plurality of positive electrode active material particles, and the plurality of first solid electrolyte particles; the negative electrode includes a plurality of second groups each including a plurality of negative electrode active material particles, a plurality of second solid electrolyte particles, and a second graphene compound that wraps around the plurality of negative electrode active material particles and the plurality of second solid electrolyte particles; The battery further comprises third solid electrolyte particles positioned between the positive electrode and the negative electrode.

5. having a positive electrode and a negative electrode, the negative electrode includes a plurality of second groups each including a plurality of negative electrode active material particles, a plurality of second solid electrolyte particles, and a second graphene compound that wraps around the plurality of negative electrode active material particles and the plurality of second solid electrolyte particles; The battery further comprises third solid electrolyte particles positioned between the positive electrode and the negative electrode.

6. 5. The battery according to claim 1, wherein the first solid electrolyte particles, the second solid electrolyte particles, and the third solid electrolyte particles have the same component.

7. A battery according to any one of claims 1 to 4, wherein the second solid electrolyte particles and the third solid electrolyte particles have the same components.

8. 8. The battery according to claim 1, wherein the positive electrode active material particles contain any one of cobalt, nickel, magnesium, and aluminum.

9. 9. The battery according to claim 1, wherein the negative electrode active material particles contain any one of silicon, titanium, and carbon.

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