electrode

Abstract

To provide a negative electrode with minimal degradation. Or, to provide a novel negative electrode. Or, degradation is To provide a small number of energy storage devices, or to provide a novel energy storage device. [Solution] A silicon compound comprising silicon, graphite, and graphene compound, with a particle size of 1 μm or less. The particles adhere to graphite particles that are more than 10 times the size of silicon particles, and the graphene compound adheres to silicon This electrode is in contact with the graphite particles, covering the condensate particles.

Description

[Technical Field]

[0001] This relates to electrodes and methods for manufacturing them, or to active materials contained in electrodes and methods for manufacturing them. Or, it relates to secondary batteries and methods for manufacturing them, or it includes vehicles, etc., that have secondary batteries. This relates to mobile devices, as well as portable information terminals, electronic devices, etc.

[0002] One aspect of the present invention relates to a product, a method, or a method of manufacture; or, the present invention relates to a process , relating to machines, manufacturers, or compositions of matter One aspect of the present invention relates to semiconductor devices, display devices, light-emitting devices, energy storage devices, lighting devices, and electronic devices. , or relating to methods for manufacturing them.

[0003] In this specification, "electronic equipment" refers to all devices that have an energy storage device. Electro-optical devices and information terminal devices with energy storage devices are all electronic devices.

[0004] In this specification, "energy storage device" refers to all elements and devices that have an energy storage function. For example, energy storage devices such as lithium-ion secondary batteries (also called secondary batteries), This includes lithium-ion capacitors and electric double-layer capacitors. [Background technology]

[0005] In recent years, various energy storage technologies have emerged, such as lithium-ion secondary batteries, lithium-ion capacitors, and air batteries. The development of such devices is thriving, particularly lithium-ion batteries with high power output and high energy density. Rechargeable batteries are used in mobile devices such as mobile phones, smartphones, and laptop computers. In addition, portable music players, digital cameras, medical equipment, or hybrid vehicles (HV), electric Next-generation clean energy vehicles such as electric vehicles (EVs) or plug-in hybrid vehicles (PHVs), etc., have seen a rapid expansion in demand along with the development of the semiconductor industry and have become indispensable in modern information-based societies as an energy source capable of repeated charging. With the development of the semiconductor industry, the demand for such next-generation clean energy vehicles as electric vehicles (EVs), plug-in hybrid vehicles (PHVs), etc., has rapidly expanded and they have become indispensable in modern information-based societies as an energy source capable of repeated charging. As an energy source that can be repeatedly charged, it has become an essential part of modern information-based society.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] Secondary batteries used in mobile bodies such as electric vehicles and hybrid vehicles need to have increased capacity to extend the driving range. Therefore, it is necessary to increase the capacity.

[0008] In addition, in portable terminals and the like, power consumption is increasing with the increase in functionality. Also, secondary batteries used in portable terminals and the like are required to be miniaturized and lightweight. Therefore, there is also a demand for higher capacity in secondary batteries used in portable terminals. For secondary batteries used in portable terminals, miniaturization and weight reduction are required. Therefore, there is also a demand for higher capacity in secondary batteries used in portable terminals. Even for secondary batteries used in portable terminals, there is a requirement for higher capacity.

[0009] In addition to its stability, it is important for a secondary battery to have a high capacity. Alloy-based materials such as silicon-based materials have a high capacity and are promising as active materials for secondary batteries. However, alloy-based materials with a high charge-discharge capacity <000^098>have problems such as pulverization and shedding of the active material due to volume changes during charge and discharge, and sufficient cycle characteristics have not been obtained. With high charge-discharge capacity alloy-based materials, problems such as pulverization and shedding of the active material occur due to volume changes during charge and discharge, and sufficient cycle characteristics have not been obtained. As a result, sufficient cycle characteristics have not been achieved.

[0010] To improve the problems of alloy-based materials as described above, an alloy-based material and graphite or a carbonaceous material Compounding with other materials is being considered. Patent Document 1 describes the bonding of silicon-containing particles and carbon-containing particles. A composite material is described in which a coating layer made of carbon is formed on the surface of a porous particle nucleus composed of a combination of particles. Patent Document 2 describes a composite material containing silicon (Si), lithium fluoride (LiF), and carbon material. Particles are described. However, in all of the above literature, the combined charge and discharge To adequately resolve the problems of pulverization and detachment of active material due to the expansion of gold-based materials It's not there yet.

[0011] The electrodes of a secondary battery are composed of materials such as active material, conductive agent, and binder. The higher the proportion of materials that contribute to capacity, such as the active material, the greater the capacity of the secondary battery. This is possible. By having a conductive agent in the electrode, the conductivity of the electrode is enhanced, resulting in excellent output characteristics. This can be obtained. Also, in the charging and discharging of secondary batteries, the active material repeatedly expands and contracts. As a result, peeling of the active material, interruption of the conductive path, etc. may occur in the electrode. In such cases, the presence of a conductive agent and binder in the electrode can lead to the peeling and conduction of the active material. The interruption of the electric path can be suppressed. On the other hand, by using a conductive agent and a binder, As a result, the proportion of active material decreases, which may reduce the capacity of the secondary battery.

[0012] One aspect of the present invention aims to provide an electrode having excellent properties. One aspect of the invention aims to provide an active material having excellent properties. One aspect of the invention aims to provide a novel electrode.

[0013] Alternatively, one aspect of the present invention aims to provide a mechanically robust negative electrode. One aspect of the present invention aims to provide a mechanically robust positive electrode. Alternatively, the present invention One aspect of the present invention aims to provide a high-capacity negative electrode. Alternatively, one aspect of the present invention is The objective is to provide a positive electrode with high capacity. Alternatively, one aspect of the present invention provides a positive electrode with less degradation. The objective is to provide a negative electrode. Alternatively, one aspect of the present invention provides a positive electrode that exhibits less degradation. The task is to accomplish this.

[0014] Alternatively, one aspect of the present invention aims to provide a secondary battery that undergoes less degradation. One aspect of the present invention aims to provide a highly safe secondary battery. One aspect of the invention aims to provide a secondary battery with high energy density. Or, One aspect of the present invention aims to provide a novel secondary battery.

[0015] Furthermore, the description of these problems does not preclude the existence of other problems. One embodiment does not need to solve all of these problems. It is possible to extract other problems from the description of the claims. [Means for solving the problem]

[0016] An electrode according to one aspect of the present invention has a material having a particle and a sheet-like shape, wherein the particles are The material having one particle and a second particle, the first particle and the sheet-like shape The material having a particle size larger than that of the second particle and a sheet-like shape with respect to the first particle, The material has a region in which the second particle is located between the first particle and the material having a sheet-like shape. It has a region where the material and the object come into contact.

[0017] Furthermore, an electrode according to one aspect of the present invention comprises a material having a particle and sheet-like shape, and the particle The child has a first particle and a second particle, and the first particle and the sheet-like shape The material has a particle size larger than the second particle and has a sheet-like shape. The second particle, located on the surface of the particle, is covered, wrapped around, or clings to. It has a region that is in contact with the first particle.

[0018] A sheet-like material has a first region, and the first region is terminated by hydrogen atoms. It is preferable that the ends are connected. The first region is, for example, one atom that can bond with hydrogen, and the atom This is a region composed of hydrogen atoms bonded to and . Alternatively, the first region is, for example, This is a region containing multiple atoms that can bond with hydrogen.

[0019] The hydrogen atoms in the first region and the functional groups terminating the surface of the first or second particle The oxygen atoms present can form hydrogen bonds.

[0020] The sheet-like material is curved by intermolecular forces to approach the particles, and hydrogen Through bonding, the sheet-like material can adhere to the particles. The sheet-like material has multiple regions terminated by hydrogen atoms on the sheet surface. It is preferable to have it.

[0021] Alternatively, the first region may be terminated by a functional group having oxygen. Examples of functional groups include hydroxyl groups, epoxy groups, carboxyl groups, and so on. Hydrogen atoms in droxy groups and carboxyl groups, etc., have functional groups that terminate the particles. It can form hydrogen bonds with oxygen atoms. Also, hydroxyl groups, epoxy groups and The oxygen atom of the carboxyl group forms a hydrogen bond with the hydrogen atom of the functional group terminating the particle. It can form a combination.

[0022] Furthermore, the sheet-like material has a second region terminated by fluorine atoms. In this case, the fluorine atom in the second region and the hydrogen atom in the functional group terminating the particle However, hydrogen bonds can be formed. This allows the sheet-like material to This makes the particles more likely to stick to each other.

[0023] Furthermore, the first region may have holes formed on the sheet surface, and the holes may be, for example, annular. It is composed of multiple atoms bonded together and an atom terminating those multiple atoms. These multiple atoms may be terminated by functional groups.

[0024] The particles in the electrode according to one aspect of the present invention preferably function as an active material, for example. In one aspect of the present invention, a material that functions as an active material can be used as the particles in the electrode. It can. Or, the particles of the electrode according to one aspect of the present invention may be, for example, a material that functions as an active material. It is preferable to have the following. Furthermore, the electrode of one aspect of the present invention has a sheet-like shape. The material is preferably one that functions as a conductive agent, for example. In one embodiment of the present invention, hydrogen The bonding allows the conductive agent to adhere to the active material, thus enabling the creation of highly conductive electrodes. It is possible.

[0025] Furthermore, the first particle in the electrode according to one aspect of the present invention is a first active material, and the second particle is It is preferable that the first particle functions as a second active material. It is preferable that the active material undergoes little change and has a particle size at least 10 times that of the second particle. Preferably, the sheet-shaped material of the electrode in one aspect of the present invention may be, for example, If so, it is preferable that it functions as a conductive agent. In one embodiment of the present invention, a sheet-like shape is The material having such a structure encloses the second particle located on the surface of the first particle. Because it can come into contact with the first particle, or cling to it, it has high conductivity Electrodes can be realized.

[0026] Furthermore, the sheet-like material adheres to the active material, thus affecting the electrode. This prevents the peeling of the active material. Furthermore, a sheet-like material can contain multiple active materials. It can also cling to the material over a wide area. As an active material, it undergoes large volume changes during charging and discharging. When using materials such as silicon, repeated charging and discharging can cause the active material and conductive agent to react. The adhesion between multiple active materials may gradually weaken, potentially leading to the peeling of the active material from the electrode. In one embodiment of the present invention, when silicon is used as the second particle, the volume change associated with charging and discharging The second particle, which is located on the surface of the first particle with a smaller particle size, is covered, or enclosed, Because it can come into contact with the first particle in a clinging manner, during repeated charging and discharging Even when exposed to air, the peeling of the active material from the electrode is suppressed, resulting in a stable and highly reliable electrode. This is possible. Silicon has a very high theoretical capacity of 4000mAh / g or more, and secondary The energy density of the battery can be increased. Charge / discharge as a first particle in one aspect of the present invention. An active material with minimal volume change is used, and a material containing silicon as the second particle is used. This results in a high energy density and stable characteristics even after repeated charging and discharging. This makes it possible to create highly reliable rechargeable batteries.

[0027] A second particle in one aspect of the present invention has a silicon atom terminated by a hydroxyl group. Alternatively, particles according to one aspect of the present invention have silicon and at least a portion of their surface is hydroxyl Terminated by a cy group. Alternatively, particles according to one embodiment of the present invention have at least a portion of their surface hyd It is a silicon compound terminated by a roxy group. Alternatively, the particles according to one embodiment of the present invention are shown in the table. This is a silicon in which at least a portion of the surface is terminated with hydroxyl groups.

[0028] Alternatively, in one aspect of the present invention, the first particle has a first material, and the second particle has a second material It is preferable that it has

[0029] Furthermore, in the above configuration, the first material is graphite, easily graphitizable carbon, poorly graphitizable carbon, and kar It is one or more selected from von nanotubes, carbon black, and graphene. preferable.

[0030] Furthermore, in the above configuration, the second material is silicon, tin, gallium, aluminum, and Selected from luminum, lead, antimony, bismuth, silver, zinc, cadmium, and indium. It is preferable that the metal or compound has one or more elements.

[0031] It is preferable to use a graphene compound as the material having a sheet-like shape. For example, as a phen compound, carbon atoms within the sheet surface may be other atoms or functional groups. It is preferable to use graphene terminated by [a specific method / method].

[0032] Graphene has a structure in which its edges are terminated by hydrogen. The material has a two-dimensional structure formed of a six-membered carbon ring, and the two-dimensional structure has defects or pores. When a defect is formed, carbon atoms near the defect, or carbon atoms constituting the pore, can form various functional groups. Alternatively, the molecule may be terminated by atoms such as hydrogen or fluorine atoms.

[0033] In one embodiment of the present invention, defects or pores are formed in graphene, and carbon atoms near the defects, Alternatively, the carbon atoms constituting the pores may be hydrogen atoms, fluorine atoms, hydrogen atoms, or fluorine atoms By terminating with functional groups, oxygen-containing functional groups, etc., the particles of the electrode Graphene can be made to cling to it. However, defects or The pores are preferably in an amount that does not significantly impair the overall conductivity of the graphene. In this context, "forming a pore" refers to, for example, atoms at the periphery of the opening, atoms at the end of the opening, etc.

[0034] One embodiment of the present invention is a graphene compound comprising a 7-membered ring or more composed of carbon, preferably 18 It has a hole composed of a multi-membered ring of 15 or more members, more preferably 22 or more members. One of the carbon atoms in the multi-membered ring is terminated by a hydrogen atom. In one embodiment of the present invention, One carbon atom in the multi-membered ring is terminated by a hydrogen atom, and the other is terminated by a fluorine atom. Furthermore, in one embodiment of the present invention, the carbon atoms of the multi-membered ring are terminated with fluorine. The number of carbon atoms is less than 40% of the number of carbon atoms terminated by hydrogen atoms.

[0035] A graphene compound according to one aspect of the present invention has pores, the pores being a plurality of carbon atoms bonded in a ring. It is composed of multiple atoms or functional groups terminating the carbon atoms, etc., and bonded in a cyclic manner. One or more of the carbon atoms are from Group 13, such as boron, or from Group 15, such as nitrogen. It may also be substituted with a Group 16 element such as oxygen.

[0036] In one embodiment of the present invention, the graphene compound has carbon atoms other than the edge atoms that are hydrogen atoms, fluorine atoms Terminated by a functional group having a hydrogen atom or a fluorine atom, a functional group having oxygen, etc. It is preferable that the graphene compound of one aspect of the present invention is, for example, graphene Near the center of the surface, carbon atoms are surrounded by hydrogen atoms, fluorine atoms, hydrogen atoms, or fluorine atoms. It is preferable that the molecule be terminated by a functional group having a molecule, a functional group having oxygen, etc.

[0037] One aspect of the present invention comprises a first active material, a second active material, and a graphene compound. The first active material has silicon with a particle size of 1 μm or less, and the second active material has larger particles than the first active material. The graphene compound has a yellow graphite, the first active material is located on the surface of the second active material, and the graphene compound is These are electrodes that come into contact with the first active material and the second active material.

[0038] In the electrode described in any one of the above, the graphene compound covers the first active material. It is preferable that the sea urchin comes into contact with the second active material.

[0039] In the electrode described in any one of the above, the graphene compound is bound to the first active material It is preferable that the second active material comes into contact with the first active material in a way that it adheres to it.

[0040] In the electrode described in any one of the above, the first active material is a second active material and graphene It is preferable that it be located between the compounds.

[0041] In the electrode described in any one of the above, the size of the second active material is the same as the size of the first active material. It is preferable that the size is 10 times or more the size of the substance.

[0042] In the electrode described in any one of the above, the silicon has amorphous silicon. It is preferable.

[0043] In the electrode described in any one of the above, the graphene compound has pores and a plurality of carbon atoms. It has a carbon atom and one or more hydrogen atoms, and each of the one or more hydrogen atoms is a carbon atom of multiple carbon atoms One of the atoms is terminated, and a pore is formed by multiple carbon atoms and one or more hydrogen atoms. This is preferable.

[0044] Alternatively, one aspect of the present invention provides a two-way electrode having the electrode and electrolyte described in any one of the above descriptions. Next is the battery.

[0045] Alternatively, one aspect of the present invention is a mobile body having a secondary battery as described in any one of the above. .

[0046] Alternatively, one aspect of the present invention is an electronic device having a secondary battery as described in any one of the above. ru.

[0047] Furthermore, one aspect of the present invention involves mixing silicon and a solvent to produce a first mixture. Step 1 involves mixing the first mixture with graphite to produce the second mixture. A third mixture is prepared by mixing the first mixture with the second mixture and the graphene compound. Step 4 involves mixing the third mixture with the polyimide precursor and solvent to prepare the fourth mixture. The fourth step is to coat the metal foil with the fourth mixture, and the fifth step is to mix the fourth mixture The sixth step is to dry the material, and the seventh step is to heat the fourth mixture to make electrodes. The heating is performed under reduced pressure, and the graphene compound is reduced by heating. This is a method for fabricating electrodes for lithium-ion secondary batteries by imidizing a polyimide precursor.

[0048] Furthermore, in the above configuration, it is preferable that the graphene compound has graphene oxide. Preferably, the graphite is 10 times or more the size of the silicon. [Effects of the Invention]

[0049] According to one aspect of the present invention, an electrode having excellent properties can be provided. Alternatively, this According to one aspect of the invention, a novel electrode can be provided.

[0050] Furthermore, according to one aspect of the present invention, a mechanically robust negative electrode can be provided. According to one aspect of the invention, a robust positive electrode can be provided. Also, according to one aspect of the invention, This makes it possible to provide a negative electrode with less degradation. Furthermore, according to one aspect of the present invention, degradation is reduced. A positive electrode can be provided. Furthermore, according to one aspect of the present invention, a negative electrode with less degradation can be provided. This is possible. Furthermore, according to one aspect of the present invention, a positive electrode with less degradation can be provided. .

[0051] Furthermore, according to one aspect of the present invention, a secondary battery with less degradation can be provided. According to one aspect of the present invention, a highly safe secondary battery can be provided. In one embodiment, a secondary battery with high energy density can be provided. In one embodiment, a novel secondary battery can be provided.

[0052] Furthermore, the description of these effects does not preclude the existence of other effects. One embodiment does not necessarily have to possess all of these effects. Furthermore, other effects may be considered. This will become clear from the description in the specification, drawings, claims, etc., and the specification, drawings It is possible to extract effects other than those mentioned above from the descriptions in the surfaces, claims, etc. [Brief explanation of the drawing]

[0053] [Figure 1] Figures 1A and 1B show examples of cross-sections of electrodes. Figure 1C shows a perspective view of a particle. [Figure 2] Figures 2A and 2B show the changes in particle shape during charging and discharging. [Figure 3] Figures 3A and 3B show examples of graphene compound models. [Figure 4] Figure 4 shows an example of a method for manufacturing an electrode according to one aspect of the present invention. [Figure 5] Figure 5 illustrates the crystal structure of the positive electrode active material. [Figure 6] Figure 6 illustrates the crystal structure of the positive electrode active material. [Figure 7] Figure 7 shows an example of a cross-section of a secondary battery. [Figure 8] Figure 8A is an exploded perspective view of a coin-type rechargeable battery, Figure 8B is a perspective view of a coin-type rechargeable battery, and Figure 8C is a cross-sectional perspective view thereof. [Figure 9] Figures 9A and 9B show examples of cylindrical secondary batteries, Figure 9C shows examples of multiple cylindrical secondary batteries, and Figure 9D shows examples of energy storage systems having multiple cylindrical secondary batteries. [Figure 10] Figures 10A and 10B illustrate examples of secondary batteries, while Figure 10C shows the inside of a secondary battery. [Figure 11] Figures 11A, 11B, and 11C illustrate examples of secondary batteries. [Figure 12]Figures 12A and 12B show the external appearance of a secondary battery. [Figure 13] Figures 13A, 13B, and 13C illustrate the method for manufacturing a secondary battery. [Figure 14] Figure 14A is a perspective view showing the battery pack, Figure 14B is a block diagram of the battery pack, and Figure 14C is a block diagram of a vehicle with a motor. [Figure 15] Figures 15A to 15D illustrate an example of a transport vehicle. [Figure 16] Figures 16A and 16B illustrate the energy storage device. [Figure 17] Figures 17A to 17D illustrate an example of an electronic device. [Figure 18] Figures 18A and 18B are SEM images. [Figure 19] Figures 19A and 19B are SEM images. [Figure 20] Figures 20A and 20B are SEM images. [Figure 21] Figures 21A and 21B are SEM images. [Figure 22] Figures 22A and 22B show the cycle characteristics. [Figure 23] Figure 23 shows the relationship between electrode composition ratio and cycle characteristics. [Modes for carrying out the invention]

[0054] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention This is not limited to the description below, and its form and details can be changed in various ways, as is the case for those skilled in the art. This will be easily understood. Furthermore, the present invention shall be interpreted as being limited to the contents of the embodiments described below. It is not something that should be done.

[0055] Furthermore, in the drawings, the size, layer thickness, or area may be exaggerated for clarity. This may be the case. Therefore, it is not necessarily limited to that scale.

[0056] Furthermore, the ordinal numbers used in this specification, etc., as "1st," "2nd," etc., are used for convenience only. It does not indicate the order of processes or stacking order. Therefore, for example, "the first" should be written as "the second". This can be explained by appropriately replacing it with "of" or "the third of," etc. The ordinal numbers described herein do not correspond to the ordinal numbers used to specify one aspect of the present invention. There are cases where this is the case.

[0057] (Embodiment 1) This embodiment describes an electrode, active material, conductive agent, etc., according to one aspect of the present invention.

[0058] <Example of an electrode> Figure 1A is a schematic cross-sectional view showing an electrode according to one embodiment of the present invention. The electrode 570 shown in Figure 1A is It can be applied to the positive and / or negative electrodes of a secondary battery. Electrode 570 collects current. It includes at least the body 571 and the active material layer 572 formed in contact with the current collector 571.

[0059] Figure 1B is an enlarged view of the area enclosed by the dashed line in Figure 1A. As shown in Figure 1B, The material layer 572 consists of a first particle 581, a second particle 582, a graphene compound 583, The electrolyte 584 is present, and the graphene compound 583 has a sheet-like shape. Figure 1C The graphene compound 583 is located on the surface of the second particle 582 which is located on the surface of the first particle 581. The way in which it comes into contact with the first particle 581 is such that it covers, envelops, or clings to it. This is a schematic diagram illustrating the function of the first particle 581 and the second particle 582 as active material. Materials can be used. Alternatively, at least the second particle 582 may be an active material. It is preferable to have a material that functions in this way. Also, the graphene compound 5 of the electrode 570 83 is preferably used as a conductive agent. In one embodiment of the present invention, as a conductive material When graphene compound 583 is used, it can cling to the active material by hydrogen bonding. Therefore, it is possible to realize electrodes with high conductivity.

[0060] Various materials can be used as the first particle 581 and the second particle 582. When particles according to one embodiment of the present invention are used as particle 1 581 and particle 2 582, see Figure 1B And as shown in Figure 1C, the first particle 581 and the second particle 582 and graphene compound 5 The affinity with 83 is improved, and as shown in Figures 1B and 1C, graphene compound 583, The second particle 582 located on the surface of the first particle 581 is covered, encased, The particles can come into contact with the first particle 581 in a clinging manner. For example, particles having oxygen-containing functional groups or fluorine in the surface layer, or acid on the surface. Particles having a functional group containing an element or a region terminated by a fluorine atom can be used. The graphene compound 583 binds to the first particle 581 and the second particle 582. Because it can adhere, it is possible to realize electrodes with high conductivity. The state of being in contact with something can also be described as being in close contact rather than just touching at a point. It can also be rephrased as being in contact along the surface of the particles. It can also be said that they are in contact. Let the first particle 581 and the second particle 582 The materials that can be used will be described later.

[0061] Regarding the case where an active material with a large volume change during charging and discharging is used as the second particle 582, Next, we will explain using Figure 2. The first particle 581 and the second particle 582, and the sheet-like shape The material has graphene compound 583 and, and graphene compound 583 is the first The second particle 582 located on the surface of particle 581 is covered, encased, or Figure 2A shows how the second particle 582 comes into contact with the first particle 581 in a clinging manner. It is located between the first particle 581 and the graphene compound 583, and graphene Compound 583 is in contact with the first particle 581 and the second particle 582. It is also possible. The volume of the second particle 582 shown in Figure 2A increases due to charging or discharging. Figure 2B shows the case where the graphene compound 583 is located on the surface of the first particle 581. The first particle covers, envelops, or clings to the second particle 582. Because it is in contact with particle 581, the volume of the second particle 582 increases due to charging or discharging. Even if this occurs, the electrical contact between the second particle 582 and the first particle 581 is maintained. This can be achieved. Furthermore, it can suppress the peeling of the active material from the electrodes.

[0062] The graphene compound 583 is attached to the active material such as the first particle 581 and the second particle 582. When the materials come into close contact, the contact area between the graphene compound 583 and the active material increases. Furthermore, the conductivity of electrons moving through graphene compound 583 is improved. Also, during charging and discharging... When the volume of the active material changes significantly, graphene compound 583 clings to the active material. By making contact in such a way, it is possible to effectively prevent the active material from falling off, and these The effect can be even more pronounced when the materials are in close, clinging contact. Here, graphene compound 583 has pores large enough to pass Li ions, and the number of pores is Graphene It is desirable to have a sufficient amount of phen compound 583 without interfering with its electronic conductivity.

[0063] In this example, graphene compound 583 is used as the sheet-like material. Although an example was given, the material having a sheet-like shape is limited to graphene compound 583. Alternatively, other highly electronically conductive materials in a sheet-like shape may be used.

[0064] The active material layer 572, in addition to the graphene compound 583, contains carbon black, graphite, and carbon It can contain carbon-based materials such as fibers and fullerenes. For example, carbon black. Acetylene black (AB), etc., can be used as graphite. For example, natural graphite, Artificial graphite such as carbon microbeads can be used. These carbon-based materials These have high conductivity and can function as conductive agents in the active material layer. The carbon-based material may function as an active material.

[0065] Examples of carbon fibers include mesophase pitch carbon fibers and isotropic pitch carbon fibers. Carbon fibers can be used. In addition, carbon nanofibers or Carbon nanotubes can be used, for example, in the gas phase. It can be produced using growth methods, etc.

[0066] Furthermore, the active material layer contains metal powders such as copper, nickel, aluminum, silver, and gold as conductive agents. Alternatively, it may contain metal fibers, conductive ceramic materials, etc.

[0067] The content of the conductive additive relative to the total amount of solids in the active material layer is 0.5 wt% to 10 wt%. The lower limit is preferable, and 0.5 wt% to 5 wt% is more preferable.

[0068] Unlike granular conductive materials such as carbon black that make point contact with the active material, graphene compound 5 Since 83 enables surface contact with low contact resistance, it can be used in smaller quantities than ordinary conductive materials. The electrical conductivity between the active material and graphene compound 583 can be improved. This allows for an increase in the ratio of active material to the active material layer. This improves the discharge rate of secondary batteries. The electrical capacity can be increased.

[0069] Furthermore, since graphene compound 583 according to one aspect of the present invention has excellent lithium permeability, This will increase the charge and discharge rate of the next battery.

[0070] Particulate carbon-containing compounds such as carbon black and graphite, and carbon nanotubes Fibrous carbon-containing compounds such as these can easily enter tiny spaces. These tiny spaces are, for example, multiple spaces. This refers to the regions between active materials. Carbon-containing compounds that easily enter minute spaces and multiple particles By combining sheet-like carbon-containing compounds such as graphene, which can impart conductivity, By using it in this way, the electrode density can be increased, and a superior conductive path can be formed. Furthermore, by having an electrolyte according to one aspect of the present invention, the stability of the operation of the secondary battery is improved. It can be improved. That is, a secondary battery according to one aspect of the present invention has a high energy density and It can combine stability and other qualities, making it effective as a secondary battery for vehicles. Number of secondary batteries As the weight of the vehicle increases, the energy required to move it also increases. The driving range will also be shorter. By using high-density rechargeable batteries, the weight of the rechargeable batteries installed in the vehicle will be reduced. Even if the same, that is, even if the total weight of the vehicle is the same, it is possible to increase the driving range. can.

[0071] Furthermore, as the capacity of a vehicle's secondary battery increases, more power is required for charging, so for a short time... It is desirable to end the charging process at that point. Also, when the vehicle brakes are applied, power is temporarily generated. Then, in so-called regenerative charging, charging is performed under high-rate charging conditions. Therefore, good rate characteristics are required for secondary batteries used in vehicles.

[0072] By using the electrolyte according to one aspect of the present invention, a secondary battery for automotive applications having a wide operating temperature range is available. You can obtain a battery.

[0073] Furthermore, a secondary battery according to one aspect of the present invention can be miniaturized due to its high energy density. Because of its high conductivity, rapid charging is also possible. Therefore, the configuration of a secondary battery according to one embodiment of the present invention is portable It is also effective on mobile information terminals.

[0074] The active material layer 572 preferably has a binder (not shown). The binder is, for example The binder binds or fixes the electrolyte and the active material. The binder also binds the electrolyte and carbon-based material and the active material. The ability to bind or fix together materials and carbon-based materials, multiple active materials, multiple carbon-based materials, etc. can.

[0075] As a binder, polystyrene, methyl polyacrylate, polymethyl methacrylate ( Methyl methacrylate (PMMA), sodium polyacrylate, polyvinyl alcohol Polyethylene oxide (PVA), polyethylene oxide (PEO), polypropylene oxide, polyimide Polyvinyl chloride, polytetrafluoroethylene, polyethylene, polypropylene, poly Isobutylene, polyethylene terephthalate, nylon, polyvinylidene fluoride (PVD) F) Polyacrylonitrile (PAN), ethylene propylene diene polymer, polyacetic acid It is preferable to use materials such as vinyl or nitrocellulose.

[0076] Polyimides possess excellent thermal, mechanical, and chemical stability. When polyimide is used as the additive, a dehydration reaction and a cyclization (imidization) reaction are carried out. These reactions can be carried out, for example, by heat treatment. In an electrode according to one embodiment of the present invention... , graphene having an oxygen-containing functional group as a graphene compound, and poly as a binder When using mid, the heat treatment can also reduce the graphene compound. This allows for simplification of the process. Furthermore, due to its excellent heat resistance, it can withstand heating temperatures above 200°C, for example. Heat treatment can be performed at a temperature of 200°C or higher. This allows for a more complete reduction reaction of the graphene compound, thereby improving the conductivity of the electrode. It is possible.

[0077] Fluorine-containing polymer materials, specifically polyvinylidene fluoride ( Materials such as PVDF can be used. PVDF has a melting point in the range of 134°C to 169°C. It is a resin with excellent thermal stability.

[0078] Also, as a binder, styrene-butadiene rubber (SBR), styrene-isoprene- Styrene rubber, acrylonitrile-butadiene rubber, butadiene rubber, ethylene-propion It is preferable to use rubber materials such as lendiene copolymers. Also, as a binder, Fluorocarbon rubber can be used.

[0079] Furthermore, it is preferable to use a water-soluble polymer as the binder. As molecules, for example, polysaccharides can be used. As for polysaccharides, carboxymethyl Cholecellulose (CMC), methylcellulose, ethylcellulose, hydroxypropyl Cellulose derivatives such as cellulose, diacetylcellulose, and regenerated cellulose, or syrup Powders and other forms can be used. Furthermore, these water-soluble polymers can be used in combination with the aforementioned rubber materials. It is even preferable to use it in this way.

[0080] You may use a combination of several of the binders mentioned above.

[0081] Furthermore, the graphene compound 583 is flexible and pliable, and the second particle 58 2. It can cling to things like natto. Also, for example, the second particle 582 can be attached to soybeans. The graphene compound 583 can be likened to a viscous component, such as polyglutamic acid. This is possible. The graphene compound 583 is an electrolyte in the active material layer 572, and the second particle 582 By arranging multiple active materials, multiple carbon-based materials, etc., between them, In addition to forming good conductive paths within the active material layer 572, the graphene compound 583 is used These materials can be bound or fixed together. Also, for example, multiple graphenes Composition 583 creates a three-dimensional network structure, a structure in which polygons are arranged, for example, a matrix of hexagons. It forms a honeycomb structure with a spiky arrangement, and the network contains an electrolyte, multiple active materials, and multiple carbon-based materials. By arranging materials such as these, the graphene compound 583 forms a three-dimensional conductive path. Furthermore, it is possible to suppress the loss of electrolyte from the current collector. Also, the polygon is In the arranged structure, polygons with different numbers of sides may be mixed together. Therefore, graphene compound 583 functions as a conductive agent in the active material layer 572. It can also function as a binder.

[0082] The first particle 581 and the second particle 582 have rounded shapes, angular shapes, etc. It can have various shapes. Also, in the cross-section of the electrode, the first particle 581 and The second particle 582 has various cross-sectional shapes, such as circles, ellipses, curved figures, polygons, etc. This is possible. For example, Figures 1B and 1C show, as an example, the first particle 581 of particle 582. The first particle 581 and the second particle have a rounded cross-section, and the second The cross-section of particle 582 may have corners. Alternatively, it may have a portion that is rounded and a portion that has corners. stomach.

[0083] <Graphene compound> In this specification, graphene compounds refer to graphene, multilayer graphene, and multi-gra Fen, graphene oxide, multilayer graphene oxide, multi-graphene oxide, reduced oxide Graphene, reduced multilayer graphene oxide, reduced multilayer graphene oxide, graph Includes graphene quantum dots, etc. Graphene compounds are compounds that have carbon atoms and are formed in flat, sheet-like, or other shapes. It refers to a structure that has a shape and is formed by a two-dimensional structure made of a six-membered carbon ring. The resulting two-dimensional structure can be described as a carbon sheet. The graphene compound has an oxygen-containing functional. It may have groups. Furthermore, the graphene compound preferably has a bent shape. Graphene compounds can be rolled up and form carbon nanofibers.

[0084] In this specification, graphene oxide refers to, for example, a material having carbon and oxygen, and in a sheet-like form. It refers to a substance that has functional groups, particularly epoxy groups, carboxyl groups, or hydroxyl groups. .

[0085] In this specification, reduced graphene oxide refers to, for example, a substance having carbon and oxygen, and This refers to a structure that has a T-shape and a two-dimensional structure formed from a six-membered carbon ring. It could be said that a single reduced graphene oxide sheet functions, but multiple sheets are stacked together. It may be reduced graphene oxide has a carbon concentration greater than 80 atomic%. The material has a portion where the oxygen concentration is between 2 atomic% and 15 atomic%. This is preferable. By using such carbon and oxygen concentrations, a small amount of conductive material can be used. It can function as an electrical material. Furthermore, reduced graphene oxide exhibits a Raman spectrum. It is preferable that the intensity ratio of the G band to the D band, G / D, is 1 or greater. Reduced graphene oxide, with such a strength ratio, can be used as a highly conductive material even in small quantities. It is possible.

[0086] By reducing graphene oxide, pores can be created in the reduced graphene oxide. It is sometimes possible.

[0087] Furthermore, as a graphene compound, a material in which the ends of graphene are terminated with fluorine is used. That's good too.

[0088] In the longitudinal section of the active material layer, a sheet-like gradient is found in the internal region of the active material layer, which is roughly uniform. The graphene compounds are dispersed. Multiple graphene compounds partially cover multiple granular active materials. Because they are formed to adhere to the surface of a sea urchin or multiple granular active materials, they It is in surface contact with it.

[0089] Here, multiple graphene compounds bond together to form a network of graphene compounds. Forming a material sheet (hereinafter referred to as graphene compound net or graphene net) This is possible. When the active material is covered with a graphene net, the graphene net interacts with the active material. It can also function as a binder to combine them. Therefore, the amount of binder can be reduced. Because it is possible or not to use, the active ingredients in the electrode volume and electrode weight The ratio of quality can be improved. In other words, the charge and discharge capacity of the secondary battery can be increased. It is possible.

[0090] Here, graphene oxide is used as the graphene compound and mixed with the active material to form an active material layer. It is preferable to reduce the graphene oxide after forming the layer. In other words, the completed active material layer It is preferable that the active material has reduced graphene oxide. By using graphene oxide, which has extremely high dispersibility in polar solvents, when forming the layer... This allows the graphene compound to be dispersed approximately uniformly within the internal region of the active material layer. .

[0091] A dispersion in which graphene oxide is dispersed in a solvent in a generally uniform manner is applied to the current collector, and the solvent is vaporized. In the active material layer produced by removing and then reducing graphene oxide, the active material The graphene compounds in the layers partially overlap. In this way, reduced graphene oxide The fen are dispersed to the extent that they are in surface contact with each other, forming a three-dimensional conductive path. This can be done. Furthermore, the reduction of graphene oxide may be carried out, for example, by heat treatment, or by... It may also be done using the original agent.

[0092] Furthermore, by pre-covering the surface of the active material with a graphene compound, a conductive coating is formed on the surface of the active material. By forming it on a surface and further electrically connecting the active materials with a graphene compound, a conductive path is created. It can also be formed.

[0093] In one embodiment of the present invention, the graphene compound preferably has pores in a portion of the carbon sheet. In a graphene compound according to one aspect of the present invention, lithium ions and the like are present in a part of the carbon sheet. By providing pores through which carrier ions can pass, the graphene compound is covered On the surface of the active material, insertion and removal of carrier ions becomes easier, improving the rate characteristics of the secondary battery. This can improve the performance. The holes provided in a part of the carbon sheet are voids, defects, or air pockets. They may be called upon.

[0094] A graphene compound according to one aspect of the present invention comprises a plurality of carbon atoms and one or more fluorine atoms. It is preferable that the pores are provided. Furthermore, the plurality of carbon atoms are bonded in a ring. Preferably, one or more of the cyclically bonded carbon atoms are terminated by the fluorine. It is preferable. Fluorine has high electronegativity and easily becomes negatively charged. When lithium ions approach, an interaction occurs, the energy stabilizes, and lithium ions The barrier energy required for the ions to pass through the pores can be lowered. Therefore, graphene compounds Because the pores contain fluorine, lithium ions can easily pass through even small pores. Furthermore, graphene compounds with excellent conductivity can be realized. One or more of the carbon atoms that combine may be terminated by hydrogen.

[0095] Figures 3A and 3B show an example of the structure of a graphene compound with pores.

[0096] The structure shown in Figure 3A has a 22-membered ring, and of the carbon atoms constituting the 22-membered ring, 8 carbon atoms are Each is terminated by hydrogen. In addition, in graphene, two linked 6-membered rings are taken It can also be said that it has a structure in which the carbon atom that was bonded to the removed 6-membered ring is terminated with hydrogen. ru.

[0097] The structure shown in Figure 3B has a 22-membered ring, and of the carbon atoms constituting the 22-membered ring, 8 carbon capsules Furthermore, six carbon atoms are terminated by hydrogen atoms, and two carbon atoms are terminated by fluorine atoms. In Raffen, two linked 6-membered rings are removed, and the removed 6-membered rings are bonded to each other. It can also be said that it has a structure in which carbon is terminated with hydrogen or fluorine.

[0098] Hydroxyl-terminated silicon has hydrogen from the hydroxyl group on the silicon surface, Between the hydrogen atoms or fluorine atoms of the graphene compound Because hydrogen bonds are formed, silicon terminated with a hydroxyl group has pores. It is thought to have a strong interaction with phen compounds.

[0099] Graphene compounds have fluorine in addition to hydrogen, which affects the oxygen atom of the hydroxyl group. In addition to hydrogen bonding between the hydrogen atoms of the graphene compound and the hydrogen atoms of the hydroxyl group, Hydrogen bonds are also formed between the fluorine atoms of the rhaffen compound, and the particles containing silicon and graph It is possible that the interaction with the ene compound becomes stronger and more stable.

[0100] If graphene has pores, for example, Raman spectroscopy mapping measurements can be used to determine the location of the pores. It may be possible to observe spectra based on the characteristics caused by them. Also, the bonds and tubes that make up the pores It may be possible to observe active groups, etc., using ToF-SIMS. In addition, TEM observation may reveal the pores. It may be possible to analyze the vicinity, the area around the hole, etc.

[0101] <An example of a negative electrode active material> When electrode 570 is the negative electrode, a particle having a negative electrode active material is used as the second particle 582. It can be used as a negative electrode active material, a material that can react with carrier ions in a secondary battery. Materials capable of inserting and removing carrier ions, and alloying with metals that serve as carrier ions. Using materials capable of reaction, materials capable of dissolving and precipitating metals that act as carrier ions, etc. It is preferable to do so.

[0102] An example of a negative electrode active material is described below.

[0103] Silicon can be used as the negative electrode active material. Electrode 570 is the second particle 582 It is preferable to use silicon-containing particles.

[0104] Furthermore, the negative electrode active material of the second particle 582 is tin, gallium, aluminum, Choose from germanium, lead, antimony, bismuth, silver, zinc, cadmium, and indium. A metal or compound having one or more elements can be used. Examples of alloying compounds used include Mg2Si, Mg2Ge, Mg2Sn, and SnS2. , V2Sn3, FeSn2, CoSn2, Ni3Sn2, Cu6Sn5, Ag3Sn, A g3Sb, Ni2MnSb, CeSb3, LaSn3, La3Co2Sn7, CoSb3 Examples include InSb and SbSn.

[0105] Furthermore, silicon contains impurity elements such as phosphorus, arsenic, boron, aluminum, and gallium. Materials with added and reduced resistance may be used. Alternatively, lithium-predoped silicon materials may be used. You may use a different material. Pre-doping methods include lithium fluoride, lithium carbonate, etc. and silicon Methods such as mixing and annealing, mechanical alloying of lithium metal and silicon, etc. There is a method for this. Furthermore, after forming the electrodes, they can be combined with electrodes made of lithium metal or other materials for charging and discharging. The electrode is doped with lithium, and then the doped electrode is used to form the counter electrode (for example) Alternatively, a secondary battery may be manufactured by combining a pre-doped negative electrode with a positive electrode.

[0106] For example, nanosilicon particles can be used as the second particle 582. The average diameter of the particles is preferably 5 nm or more and less than 1 μm, more preferably 10 nm or less. The wavelength is 300 nm or less, and more preferably 10 nm to 100 nm.

[0107] The nanosilicon particles may have a spherical shape or a flattened spherical shape. Often, they may also have a rectangular prism shape with rounded corners. The size of the nanosilicon particles is, for example, For example, the D50 for laser diffraction particle size distribution measurement is preferably 5 nm or more and less than 1 μm. Preferably 10 nm to 300 nm, even more preferably 10 nm to 100 nm Below. Here, D50 refers to the cumulative amount in the cumulative particle amount curve of the particle size distribution measurement results. The median particle size is the particle size when it accounts for 50% of the total particle size. Particle size is measured by laser. Not limited to laser diffraction particle size distribution measurements, but also in cases below the lower limit of measurement for laser diffraction particle size distribution measurements. In some cases, the major axis of the particle cross-section may be measured by analysis such as SEM or TEM.

[0108] It is preferable that the nanosilicon particles have amorphous silicon. It is preferable that the nanosilicon particles have polycrystalline silicon. It is preferable that it has crystalline silicon. Also, the nanosilicon particles have a crystalline region, It may have amorphous regions.

[0109] For example, a material containing silicon is SiO x (x is preferably less than 2, and more preferably Materials with a ratio of 0.5 to 1.6 can be used.

[0110] For example, a silicon-containing material can be used in which multiple crystal grains are present within a single particle. This is possible. For example, a form in which one particle contains one or more silicon crystal grains. It can be used. In addition, one particle has silicon oxide surrounding the silicon crystal grains. It may have a silicon oxide. The silicon oxide may also be amorphous. These may be particles coated with a graphene compound.

[0111] Furthermore, silicon-containing compounds include, for example, Li2SiO3 and Li4SiO4. Li2SiO3 and Li4SiO4 may each be crystalline. It may also be amorphous.

[0112] Analysis of silicon-containing compounds can be performed using NMR, XRD, Raman spectroscopy, SEM, TEM, and E This can be done using DX (Digital Transformation), etc.

[0113] The first particle 581 of the electrode 570 preferably has graphite.

[0114] The first particle 581 preferably functions as a negative electrode active material, and its volume changes with charging and discharging. It is even more preferable that the material has low chemical activity.

[0115] As a volume change of the first particle 581 associated with charging or discharging, the most during charging or discharging When the smallest volume is considered to be 1, it is preferable that the maximum volume during charging or discharging is 2 or less. It is more preferable that it be 1.5 or less, and even more preferable that it be 1.1 or less. .

[0116] It is desirable that the particle size of the first particle 581 be larger than the particle size of the second particle 582.

[0117] For example, in laser diffraction particle size distribution measurement, the D50 of the first particle 581 is the second The D50 of particle 582 is preferably 1.5 times or more but less than 1000 times, and 2 times or more but 500 times or less. More preferably, a ratio of 10 times or more and 100 times or less is even more preferable. Here, D50 refers to the particle size distribution measurement. In the cumulative particle amount curve of the result, the particle size when the cumulative amount accounts for 50% is, i.e. It is the median. Note that particle size measurement is limited to laser diffraction particle size distribution measurement. Alternatively, the diameter of the particle cross-section may be measured by analysis such as SEM or TEM.

[0118] Furthermore, as the first particle 581, for example, graphite, which undergoes small volume changes during charging and discharging, and is easily graphitized, may be used. Graphite carbon, non-graphitizable carbon, carbon nanotubes, carbon black, and graphene-forming carbon. Carbon-based materials such as compounds can be used.

[0119] In addition, as the first particle 581, for example, oxides having one or more elements selected from titanium, niobium, tungsten, and molybdenum can be used.

[0120] As the first particle 581, a plurality of combinations of the metals, materials, compounds, etc. shown above can be used. This is possible.

[0121] As the first particle 581, for example, SnO, SnO2, 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. <​​​​​​​​​​​​​​​​​​​​​​​​FIG. 4 is a flowchart showing an example of a method for manufacturing an electrode according to an aspect of the present invention.

[0124] First, in step S61, as the second particles 582, particles containing silicon are prepared. As the particles containing silicon, for example, the particles described as the second particles 582 above can be used.

[0125] In step S62, a solvent is prepared. As the solvent, for example, any one of water, methanol, ethanol, acetone, tetrahydrofuran (THF), dimethylformamide (DMF), N-methylpyrrolidone (NMP), and dimethyl sulfoxide (DMSO), or a mixture of two or more thereof can be used.

[0126] Next, in step S63, the particles containing silicon prepared in step S61 and the solvent prepared in step S62 are mixed, and in step S64, the mixture is recovered, and in step S65, mixture E-1 is obtained. For mixing, a kneader or the like can be used. As the kneader, for example, a planetary mixer or the like can be used.

[0127] Next, in step S72, as the first particles 581, particles containing graphite are prepared. As the particles containing graphite, for example, the particles described as the first particles 581 above can be used.

[0128] Next, in step S73, mixture E-1 and the particles containing graphite prepared in step S72 are mixed, and in step S74, the mixture is recovered, and in step S75, mixture E-2 is obtained. For mixing, a kneader or the like can be used. As the kneader, for example, a planetary mixer or the like can be used. A rotary-revolving mixer or similar device can be used.

[0129] Next, in step S80, the graphene compound is prepared.

[0130] Next, in step S81, the mixture E-2 and the graph prepared in step S80 are used. The mixture is mixed with the ethanol compound, and the mixture is recovered in step S82. The recovered mixture is A high viscosity is preferable. The high viscosity of the mixture allows for the next step S to proceed. In 83, solid kneading (kneading at high viscosity) can be performed.

[0131] Next, in step S83, the mixture is kneaded to a firm consistency. The mixture is kneaded to a firm consistency using, for example, a spatula. This can be done by kneading, which produces silicon-containing particles and graphite The graphene compound and the other compounds are well mixed, forming a mixture with excellent dispersibility. It is possible.

[0132] Next, in step S84, the solid mixture is mixed. For example, the mixing is carried out by mixing A kneading machine or similar equipment can be used. The mixed mixture is recovered in step S85.

[0133] The mixture recovered in step S85 is subjected to the process from steps S83 to 85. It is preferable to repeat the process n times. n is, for example, a natural number between 2 and 10. Furthermore, in step S83, if the mixture is dry, add the solvent. It is preferable to do so. On the other hand, if too much solvent is added, the viscosity will decrease and the effect of solid kneading will be reduced. To lower.

[0134] After repeating steps S83 to S85 n times, obtain mixture E-3 (step (P S86).

[0135] Next, in step S87, a binder is prepared. As the binder, the materials described above can be used, and it is particularly preferable to use polyimide. In step S8 7, it may be necessary to prepare a precursor of the material used as the binder. For example, a poly imide precursor is prepared.

[0136] Next, in step S88, mixture E-3 and the binder prepared in step S87 are mixed. Next, in step S89, the viscosity is adjusted. Specifically, for example , a solvent of the same type as the solvent prepared in step S62 is prepared and added to the mixture obtained in step S88 . By adjusting the viscosity, for example, the thickness, density, etc. of the electrode obtained in step S97 may be adjusted.

[0137] Next, the mixture whose viscosity was adjusted in step S89 is mixed in step S90 and recovered in step S91 to obtain mixture E-4 (step S92). The mixture E-4 obtained in step S92 is, for example, called a slurry.

[0138] Next, in step S93, a current collector is prepared.

[0139] Next, in step S94, mixture E-4 is coated on the current collector prepared in step S93​​​​​​​​ The first heating is performed at a temperature of 40°C to 200°C, preferably 50°C to 150°C. It is best to do this within a specified range. Note that the first heating step is sometimes referred to as drying.

[0141] The first heating method involves, for example, heating to a temperature of 30°C or higher and 70°C or lower for 10 minutes or more in an atmospheric environment. The heat treatment is performed on a plate, and then, for example, at room temperature or above 100°C for at least 1 hour. The heat treatment should be performed under reduced pressure conditions for a specified time or less.

[0142] Alternatively, heat treatment may be performed using a drying oven or the like. When using a drying oven, for example Heat treatment should be performed at a temperature between 30°C and 120°C for between 30 seconds and 2 hours.

[0143] Alternatively, the temperature may be increased in stages. For example, a heat treatment at 60°C or below for 10 minutes or less. After this, further heating at a temperature of 65°C or higher for at least one minute may be performed.

[0144] Next, in step S96, a second heating is performed. Polyimide is used as the binder. In this case, it is preferable that a cycloaddition reaction of the polyimide occurs by the second heating. Furthermore, a dehydration reaction of the polyimide may occur due to the second heating. Alternatively, the first heating Heat can cause a dehydration reaction of polyimide. Also, in the first heating, polyimide A cyclization reaction of mid may occur. In addition, during the second heating, a reduction reaction of the graphene compound may occur. It is preferable that a response occurs. The second heating process is referred to as imidization heat treatment, reduction heat treatment, It is sometimes called thermal reduction treatment.

[0145] The second heating is performed at a temperature of 150°C to 500°C, preferably 200°C to 450°C. It is best to do this within a certain range.

[0146] The second heating is performed, for example, under conditions of 200°C to 450°C for 1 to 10 hours. Heat treatment under reduced pressure below 0 Pa, or under an inert atmosphere such as nitrogen or argon. Just do what is right.

[0147] In step S97, an electrode is obtained in which an active material layer is provided on the current collector.

[0148] The thickness of the active material layer formed in this way is preferably, for example, 5 μm to 300 μm. More preferably, the thickness should be between 10 μm and 150 μm. Also, the active material of the active material layer The load amount is preferably, for example, 2 mg / cm³. 2 More than 50mg / cm 2 The following is acceptable.

[0149] The active material layer may be formed on both sides of the current collector, or on only one side. Alternatively, it may partially have regions where active material layers are formed on both sides.

[0150] After the solvent has evaporated from the active material layer, a compression method such as a roll press or a flat plate press is applied. Further pressing may be performed. Heat may be applied during the pressing process.

[0151] <An example of a positive electrode active material> For example, the positive electrode active material may have an olivine-type crystal structure, a layered rock salt-type crystal structure, or spin Examples include lithium-containing composite oxides having a crystalline structure of the type 1.

[0152] One aspect of the present invention involves using a positive electrode active material having a layered crystalline structure as the positive electrode active material. preferable.

[0153] An example of a layered crystal structure is the layered rock salt type crystal structure. As a lithium-containing composite oxide having a structure, for example, LiM x O y (where x > 0 and y > 0, more specifically, for example, y = 2 and 0.8 < x < 1.2), a lithium-containing composite oxide represented by can be used. Here, M is a metal element, preferably one or more selected from cobalt, manganese, nickel, and iron. Alternatively, M is, for example, two or more selected from cobalt, manganese , nickel, iron, aluminum, titanium, zirconium, lanthanum, copper, and zinc.

[0154] LiM x O y As a lithium-containing composite oxide represented by, for example, LiCoO2, LiN iO2, LiMnO_{2}, etc. can be mentioned. Also, LiNi x Co 1-x O2(0 < x < 1) As a NiCo-based lithium-containing composite oxide represented by, for example, LiM x O y As a lithium-containing composite oxide represented by, for example, LiNi x [[ID=​​​​​​​​​​​​​​​​​​​​​It is preferable to satisfy x:y:z = 5:2:3 or values in the vicinity thereof. Or as an example and, x, y, and z preferably satisfy x:y:z = 8:1:1 or values in the vicinity thereof. Or as an example, x, y, and z preferably satisfy x:y:z = 6:2:2 or values in the vicinity thereof. Or as an example, x, y, and z preferably satisfy x:y:z = 1: <00​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​b M c O d Lithium A manganese composite oxide can be used. Here, element M is other than lithium or manganese. It is preferable to use a selected metal element, or silicon, phosphorus, or nickel. This is even more preferable. Also, when measuring the entire particle of lithium manganese composite oxide, When the voltage <a / (b+c)<2、かつc>is 0, and 0.26≦(b+c) / d<0.5 It is preferable that the conditions are met. Furthermore, the metal and silicon of the entire lithium manganese composite oxide particle. The composition of phosphorus, etc., can be measured, for example, using ICP-MS (Inductively Coupled Plasma Mass Spectrometer). It is possible. Also, the oxygen composition of the entire lithium manganese composite oxide particle is, for example, E Measurement is possible using DX (energy-dispersive X-ray spectroscopy). Additionally, ICP (Integrated Cryptography) can be used. In conjunction with MS analysis, valence evaluation using molten gas analysis and XAFS (X-ray absorption fine structure) analysis is employed. It can be determined by having it. Furthermore, lithium manganese composite oxide is at least Li This refers to oxides containing thium and manganese, as well as chromium, cobalt, aluminum, nickel, Iron, magnesium, molybdenum, zinc, indium, gallium, copper, titanium, niobium, cyanoacrylate It may contain at least one element selected from the group consisting of lycon and phosphorus. stomach.

[0160] [Structure of the positive electrode active material] Materials with a layered rock salt-type crystalline structure, such as lithium cobalt oxide (LiCoO2), emit It is known to have high electrical capacity and is excellent as a positive electrode active material for secondary batteries. Examples of materials having a crystalline structure include composite oxides represented by LiMO2. ​M contains the metal Me1. Metal Me1 is one or more metals, including cobalt. Group M may include metal X in addition to metal Me1. Metal X is magnesium. Calcium, zirconium, lanthanum, barium, copper, potassium, sodium, zinc It is one or more metals selected from among them.

[0161] The Jahn-Teller effect in transition metal compounds depends on the number of electrons in the d orbitals of the transition metal. It is known that the strength of their effects varies.

[0162] In nickel-containing compounds, distortion is likely to occur due to the Jahn-Teller effect. Therefore, when charging LiNiO2 at high voltage, distortion occurs. There is a concern that the crystal structure may collapse. In LiCoO2, the Jahn-Teller effect is present. It is suggested that the resonance is low, and it may be preferable that it has better tolerance for charging at high voltages. .

[0163] The positive electrode active material will be explained using Figures 5 and 6.

[0164] A positive electrode active material produced according to one aspect of the present invention undergoes repeated high-voltage charging and discharging. This allows for a reduction in the displacement of the CoO2 layer. Furthermore, it allows for a reduction in volume changes. Yes, it is possible. Therefore, the compound can achieve excellent cycle characteristics. The compound can adopt a stable crystalline structure under high voltage charge conditions. Therefore, the compound is high When the voltage charge state is maintained, short circuits are less likely to occur. In such cases, safety is further improved, which is preferable.

[0165] In this compound, the crystal structure in a fully discharged state and in a high-voltage charged state is The change and the difference in volume when compared per the same number of transition metal atoms are small.

[0166] The positive electrode active material is preferably represented by a layered rock salt type structure, and this region is represented by space R-3m. The positive electrode active material is a region containing lithium, metal Me1, oxygen, and metal X. An example of the crystal structure of the positive electrode active material before and after charging and discharging is shown in Figure 5. Furthermore, the surface layer of the positive electrode active material is In addition to the region represented by the layered salt rock structure explained in Figure 5 below, or alternatively, It contains tannins, magnesium, and oxygen, and has crystals that are represented by a structure different from that of layered rock salt. For example, it may have titanium, magnesium, and oxygen and be represented in a spinel structure. It may have crystals.

[0167] The crystal structure of the charge depth 0 (discharge state) in Figure 5 is R-3m(O3), the same as in Figure 6. On the other hand, the positive electrode active material shown in Figure 5, when fully charged to a depth of charge (e.g., 0.8), has H1 It has a crystal structure different from the -3 type crystal structure. This structure has a space group R-3m, and the spirometry Although it does not have a Nell-type crystal structure, ions such as cobalt and magnesium are located at the oxygen 6-coordinate position. Furthermore, the arrangement of cations in this structure exhibits symmetry similar to that of a spinel. The properties are the same as the O3 type. Therefore, in this specification, this structure is referred to as the O3' type crystal structure, and This is called a pseudo-spinel type crystal structure. Therefore, the O3' type crystal structure and the pseudo-spinel type The crystal structure of and can be used interchangeably. Note that the pseudo-spinel type shown in Figure 5 In the crystal structure diagram, to explain the symmetry of the cobalt atom and the oxygen atom, Although the indication of thium is omitted, in reality, between the CoO2 layers, there is, for example, 20 ions relative to cobalt. Lithium is present in amounts less than 1%. Furthermore, O3-type and pseudo-spinel-type crystal structures exist. In both cases, a dilute amount of magnesium is present between the CoO2 layers, i.e., at the lithium sites. It is preferable to have a halogen such as fluorine randomly and dilutely present at the oxygen site. It's okay for it to exist.

[0168] Furthermore, in pseudo-spinel crystal structures, light elements such as lithium occupy the oxygen 4-coordinate position. In this case as well, the arrangement of ions has a symmetry similar to that of the spinel type.

[0169] Furthermore, the pseudo-spinel type crystal structure has Li randomly placed between the layers, but it is CdCl2 type. It can also be said that it has a crystal structure similar to that of CdCl2. The crystal structure is when lithium nickelate is charged to a depth of charge of 0.94 (Li 0.06 N The crystal structure is similar to that of iO2, but it consists of pure lithium cobalt oxide or layers rich in cobalt. It is known that rock salt-type cathode active materials do not usually adopt this crystal structure.

[0170] Layered rock salt crystals, and the anions of rock salt crystals, have a cubic close-packed structure (face-centered cubic lattice structure). ) takes this form. It is also presumed that pseudo-spinel crystals adopt a cubic close-packed structure for anions. When they come into contact, there exists a crystal plane in which the orientation of the cubic close-packed structure composed of anions is aligned. However, the space group of layered rock salt crystals and pseudo-spinel crystals is R-3m, and rock salt The space groups of type crystals are Fm-3m (the space group of a typical rock salt type crystal) and Fd-3m (the simplest). Because it is different from the space group of rock salt crystals that have symmetry, the crystal planes that satisfy the above conditions The Lars index differs between layered rock salt crystals, pseudo-spinel crystals, and rock salt crystals. In layered rock salt crystals, pseudo-spinel crystals, and rock salt crystals, anions When the orientations of the cubic close-packed structures that are formed are aligned, we say that the crystal orientations are roughly the same. There is.

[0171] In the positive electrode active material shown in Figure 5, the crystal structure when a large amount of lithium is released during high-voltage charging is observed. The structural changes are more suppressed than in the comparative example described later. For example, as shown by the dashed line in Figure 5. In these crystal structures, there is almost no displacement of the CoO2 layer.

[0172] To explain in more detail, the positive electrode active material shown in Figure 5 maintains structural stability even at high charging voltages. It has high properties. For example, in the comparative example, the charging voltage that results in an H1-3 type crystal structure is, for example, lithium Even at a voltage of approximately 4.6V, using the potential of the metal as a reference, the crystal structure of R-3m(O3) is observed. There is a range of charging voltages that can be maintained, and there is also a range where the charging voltage can be increased further, for example, lithium metal Even at voltages of approximately 4.65V to 4.7V with the potential as a reference, the pseudo-spinel type crystal structure There is a region where formation is possible. Furthermore, when the charging voltage is increased, H1-3 type crystals can finally be observed. It may be measured. Furthermore, in secondary batteries, for example, when graphite is used as the negative electrode active material... For example, even when the voltage of the secondary battery is between 4.3V and 4.5V, R-3m(O3) There is a region of charging voltage in which the crystal structure can be maintained, and there is also a region where the charging voltage is further increased, for example, Even when the potential of thium metal is between 4.35V and 4.55V, the pseudo-spinel type There is a region where a crystalline structure can be adopted.

[0173] Therefore, in the positive electrode active material shown in Figure 5, even if high-voltage charging and discharging are repeated The crystal structure is less likely to collapse.

[0174] In the pseudo-spinel type crystal structure, the coordinates of cobalt and oxygen in the unit cell are Co It can be shown that the coordinates are (0,0,0.5), O(0,0,x), and within the range 0.20≦x≦0.25. can.

[0175] Magnesium, which is randomly and dilutely present between the CoO2 layers, that is, at the lithium sites, When charged at high voltage, it has the effect of suppressing the displacement of the CoO2 layer. The presence of magnesium tends to lead to a pseudo-spinel crystal structure.

[0176] However, if the heat treatment temperature is too high, cation mixing occurs and magnesium The likelihood of magnesium entering cobaltite increases. The magnesium present in cobaltite is It does not have the effect of maintaining the structure of R-3m under high voltage charging conditions. Furthermore, the heating temperature is high If too much is used, the cobalt will be reduced to a divalent state, and the lithium will evaporate or sublimate. All of these negative consequences are a concern.

[0177] Therefore, prior to the heat treatment to distribute magnesium throughout the surface layer of the particles, It is preferable to add halogen compounds such as fluorine compounds to lithium cobalt oxide. Adding a chlorogenic compound causes a decrease in the melting point of lithium cobalt oxide. Therefore, at a temperature where cation mixing is unlikely to occur, magnesium is distributed throughout the surface layer of the particles. It becomes easier to apply. Furthermore, if a fluorine compound is present, the electrolyte will decompose and produce This is expected to improve corrosion resistance to hydrofluoric acid.

[0178] Furthermore, increasing the magnesium concentration beyond the desired value reduces its effect on stabilizing the crystal structure. In some cases, this can occur. Magnesium, in addition to lithium sites, also contains cobalt sites. This is thought to be because it will also fit into the toe box. The number of magnesium atoms in it is between 0.001 and 0.1 times the number of cobalt atoms. Preferably, greater than 0.01 and more preferably less than 0.04, and even more preferably around 0.02. The magnesium concentration shown here is, for example, determined by measuring the particle size of the positive electrode active material using ICP-MS. This could be the value obtained from elemental analysis of the entire material, or the value obtained from the raw materials during the process of manufacturing the positive electrode active material. It may also be based on the blending values.

[0179] The number of nickel atoms in the positive electrode active material is preferably 7.5% or less of the number of cobalt atoms. Preferably, the concentration is 0.05% to 4%, and more preferably 0.1% to 2%. The nickel concentration can be determined, for example, by elemental analysis of the entire particle of the positive electrode active material using ICP-MS. It may be a value obtained by the process, or it may be based on the values ​​of the raw material composition during the manufacturing process of the positive electrode active material. That's good too.

[0180] <Particle size> If the particle size of the positive electrode active material is too large, lithium diffusion becomes difficult, and when it is coated onto the current collector... This can lead to problems such as the surface of the active material layer becoming too rough. On the other hand, if it is too small, it can affect the current collector. Problems arise during coating, such as difficulty in supporting the active material layer and excessive reaction with the electrolyte. Therefore, the average particle diameter (D50: also called the median diameter) is between 1 μm and 100 μm. It is preferable that the particle size is less than or equal to m, more preferably between 2 μm and 40 μm, and more preferably between 5 μm and 30 μm. A size of μm or less is even more preferable.

[0181] <Analysis method> When a certain positive electrode active material is charged at a high voltage, it forms a pseudo-spinel type (also called an O3' structure). Whether or not a crystal structure is observed can be determined by XRD, electron diffraction, neutron diffraction, and other methods used to analyze a positive electrode charged with high voltage. This can be determined by analyzing using electron spin resonance (ESR), nuclear magnetic resonance (NMR), etc. In particular, XRD can analyze the symmetry of transition metals such as cobalt in the positive electrode active material with high resolution. It allows for comparison of crystallinity and crystal orientation, as well as periodic strain of the lattice and crystallite size. It is possible to analyze the noise, and even by directly measuring the positive electrode obtained by disassembling a secondary battery, sufficient accuracy can be obtained. It is preferable in that it allows for such things.

[0182] As previously described, the crystal structure of the positive electrode active material changes between the high-voltage charged state and the discharged state. It is characterized by minimal change. When charged at high voltage, the change from the discharged state is large. Materials in which the crystalline structure accounts for 50 wt% or more are undesirable because they cannot withstand high-voltage charging and discharging. No. And simply adding impurity elements may not result in the desired crystal structure. Caution is necessary. For example, lithium cobalt oxide containing magnesium and fluorine, Even if they share the same characteristics, when charged at high voltage, the pseudo-spinel type crystal structure is less than 60 wt% There are cases where it is on top, and cases where the H1-3 type crystal structure accounts for 50 wt% or more. At a predetermined voltage, the pseudo-spinel crystal structure becomes approximately 100 wt%, and furthermore, at the predetermined voltage... Increasing the voltage can sometimes result in the formation of an H1-3 type crystal structure. Therefore, the positive electrode active material is XRD It is preferable to analyze the crystal structure using methods such as XRD. This allows for a more detailed analysis.

[0183] However, when the positive electrode active material is in a high-voltage charged or discharged state, its crystalline structure changes when exposed to the air. Changes in structure can occur. For example, from a pseudo-spinel type crystal structure to an H1-3 type crystal structure. It may change. Therefore, all samples should be kept in an inert atmosphere such as an argon-containing atmosphere. It is preferable to handle it with your mind.

[0184] The positive electrode active material shown in Figure 6 is lithium cobalt oxide (LiCoO2) without the addition of metal X. As shown in Figure 6, the crystal structure of lithium cobalt oxide changes depending on the depth of charge.

[0185] As shown in Figure 6, lithium cobalt oxide at charge depth 0 (discharge state) has space group R- It has a region with a 3m crystal structure, and there are three CoO2 layers in the unit cell. Therefore, this crystal structure is sometimes called the O3 type crystal structure. Note that the CoO2 layer is cobalt This refers to an octahedral structure in which oxygen atoms are coordinated in six positions, and which is continuous on a plane in a state of shared edges. .

[0186] Furthermore, when the charging depth is 1, it has a crystal structure of space group P-3m1, and the unit cell contains Co One O2 layer is present. Therefore, this crystal structure is sometimes called an O1 type crystal structure.

[0187] Furthermore, lithium cobalt oxide at a charge depth of approximately 0.8 has a crystal structure of space group R-3m. It has a structure like CoO2, such as P-3m1(O1), and R-3m(O3 It can also be described as a structure in which the LiCoO2 structure, like the one shown above, is alternately stacked. The crystal structure is sometimes called the H1-3 type crystal structure. However, in reality, the H1-3 type crystal structure is The number of cobalt atoms per unit cell is twice that of other structures. However, see Figure 6. Initially, in this specification, to facilitate comparison with other structures, the c-axis of the H1-3 type crystal structure is considered unified. This will be shown using a diagram that is half the size of a net cell.

[0188] As an example, the H1-3 type crystal structure uses the coordinates of cobalt and oxygen in the unit cell, C o(0, 0, 0.42150±0.00016), O1(0, 0, 0.27671±0. It can be expressed as 00045) and O2(0,0,0.11535±0.00045). O1 and O2 are oxygen atoms, respectively. Thus, the H1-3 type crystal structure is one It is represented by a unit cell using Balt and two oxygen atoms. On the other hand, as will be described later, A pseudo-spinel crystal structure according to one aspect of the present invention is preferably composed of one cobalt and one acid It is represented by a unit cell using elements. This is the case for the pseudo-spinel structure and the H1-3 type. In the case of structure, the symmetry between cobalt and oxygen is different, and the pseudo-spinel structure is H1- This shows that the change from the structure of O3 is small compared to the type 3 structure. The choice of which unit cell to use to represent the structure can be determined, for example, by Rietveld analysis of XRD. This can be used to make a judgment. In this case, the GOF (goodness of fit) value... We should adopt smaller unit cells.

[0189] High-voltage charging such that the charging voltage is 4.6V or higher based on the oxidation-reduction potential of lithium metal. If you repeatedly charge to a deep depth of 0.8 or more, and then discharge the battery, Lithium cobalt oxide has an H1-3 type crystal structure and a R-3m(O3) structure in its discharged state. During this process, the crystal structure undergoes repeated changes (i.e., non-equilibrium phase transitions).

[0190] However, these two crystal structures have a large displacement of the CoO2 layer. (See dotted line in Figure 6) As indicated by the arrows, in the H1-3 type crystal structure, the CoO2 layer is large from R-3m(O3) It is collapsing. Such dynamic structural changes negatively affect the stability of the crystal structure. Eur.

[0191] Furthermore, the volume difference is also large. When comparing per the same number of cobalt atoms, H1-3 type crystal The difference in volume between the structure and the O3-type crystal structure in the discharged state is 3.0% or more.

[0192] In addition, the H1-3 type crystal structure has a continuous CoO2 layer, such as P-3m1(O1). The resulting structure is likely to be unstable.

[0193] Therefore, repeated high-voltage charging and discharging disrupts the crystalline structure of lithium cobalt oxide. This is because the breakdown of the crystal structure causes a deterioration in cycle characteristics. This reduces the number of sites where lithium can exist stably, and also makes lithium insertion and removal more difficult. This is thought to be because it will become more difficult.

[0194] <Electrolyte> When using a liquid electrolyte layer in a secondary battery, for example, ethylene carbonate is used as the electrolyte layer. T (EC), propylene carbonate (PC), butylene carbonate, chloroethylene Carbonate, vinylene carbonate, γ-butyrolactone, γ-valerolactone, dimethyl Diethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate Ethyl acetate (EMC), methyl formate, methyl acetate, ethyl acetate, methyl propionate, propio Ethyl phosphate, propyl propionate, methyl butyrate, 1,3-dioxane, 1,4-dioxane San, dimethoxyethane (DME), dimethyl sulfoxide, diethyl ether, methyl Diglyceride, acetonitrile, benzonitrile, tetrahydrofuran, sulfolane, sul One of the following types of tons, or two or more of these types in any combination and ratio: It is possible.

[0195] Furthermore, as the solvent for the electrolyte, an ionic liquid (a room-temperature molten salt) that is flame-retardant and non-volatile is used. By using one or more of these, the internal temperature of the secondary battery may be affected by short circuits or overcharging. Even if the temperature rises, it can prevent secondary batteries from rupturing or catching fire. Ionic liquids are... It consists of thiones and anions, and contains organic cations and anions. As organic cations, four quaternary ammonium cations, tertiary sulfonium cations, and quaternary phosphonium cations Aliphatic onium cations such as, as well as imidazolium cations and pyridinium cations. Examples include aromatic cations such as thiones. Also, monovalent amide anions are used as anions. N, monovalent methide anions, fluorosulfonic acid anions, perfluoroalkylsulfonic acid anions Honate anions, tetrafluoroborate anions, perfluoroalkylborate anions On, hexafluorophosphate anion, or perfluoroalkyl phosphate Examples include anions.

[0196] A secondary battery according to one aspect of the present invention is, for example, an alkaline battery such as sodium ions or potassium ions. Metal ions, as well as calcium ions, strontium ions, barium ions, and Lilium ions and any one of the alkaline earth metal ions such as magnesium ions It has two or more carrier ions.

[0197] When lithium ions are used as carrier ions, for example, the electrolyte is a lithium salt. Includes lithium salts such as LiPF6, LiClO4, LiAsF6, and LiBF4. , LiAlCl4, LiSCN, LiBr, LiI, Li2SO4, Li2B 10 Cl1 0, Li2B 12 Cl 12 , LiCF3SO3, LiC4F9SO3, LiC(CF3S O2)3, LiC(C2F5SO2)3, LiN(CF3SO2)2, LiN(C4F9 SO2)(CF3SO2), LiN(C2F5SO2)2, etc. can be used.

[0198] Furthermore, the electrolyte preferably contains fluorine. For example, a fluorine-containing electrolyte is fluorine An electrolyte comprising one or more cyclic carbonates and lithium ions is used. It is possible. Fluorinated cyclic carbonates improve flammability and lithium ion secondary This can improve battery safety.

[0199] As a fluorinated cyclic carbonate, fluorinated ethylene carbonate, for example, monofluorinated ethylene carbonate, Fluoroethylene carbonate (fluoroethylene carbonate, FEC, F1EC), difluoroethylene Lentinum carbonate (DFEC, F2EC), trifluoroethylene carbonate (F3E C) Tetrafluoroethylene carbonate (F4EC), etc., can be used. Oh, DFEC has isomers such as cis-4,5 and trans-4,5. , lithium ions are solvated using one or more fluorinated cyclic carbonates. Therefore, transporting the electrolyte within the electrodes during charging and discharging is important for operation at low temperatures. Therefore, fluorinated cyclic carbonate is not used as a small amount of additive, but rather during the charging and discharging of lithium. By contributing to ion transport, operation at low temperatures becomes possible. Lithium ions in secondary batteries ON moves in clusters of several to several dozen units.

[0200] By using fluorinated cyclic carbonates as the electrolyte, the solvent within the electrolyte contained in the electrode The energy required for desolvation when the lithium ions in the mixture enter the active material particles is reduced. This desolvation energy can be reduced, allowing lithium to be used even in the low-temperature range. The ON ions become easier to insert into or detach from the active material particles. Note that lithium ions are in a solvated state. While they may move in their original state, a hopping phenomenon occurs where the coordinating solvent molecules are replaced. In some cases, lithium ions become more easily desolvated, and their movement due to the hopping phenomenon occurs. This can make it cheaper and easier for lithium ions to move. The decomposition products of the electrolyte adhere to the surface of the active material, causing degradation of the secondary battery. There is a concern about this. However, if the electrolyte contains fluorine, the electrolyte will be fluid. Therefore, the decomposition products of the electrolyte become less likely to adhere to the surface of the active material. This reduces the degradation of the secondary battery. It can be suppressed.

[0201] Solvated lithium ions form clusters in the electrolyte, and in the negative electrode, positive It may move between the polarity and the negative polarity, within the positive polarity, etc.

[0202] An example of a fluorinated cyclic carbonate is shown below.

[0203] Monofluoroethylene carbonate (FEC) is represented by the following formula (1).

[0204] [ka]

[0205] Tetrafluoroethylene carbonate (F4EC) is represented by the following formula (2).

[0206] [ka]

[0207] Difluoroethylene carbonate (DFEC) is represented by the following formula (3).

[0208] [ka]

[0209] In this specification, the electrolyte refers to a solid electrolyte, a liquid electrolyte solution, or a semi-solid gel electrolyte. This is a general term that includes things like the above.

[0210] Degradation is likely to occur at interfaces within secondary batteries, such as the interface between the active material and the electrolyte. In one embodiment of a secondary battery, by having an electrolyte containing fluorine, the active material and the electrolyte To prevent degradation that can occur at the interface with the substance, typically the alteration of the electrolyte or the increase in the viscosity of the electrolyte. This can be done. In addition, for electrolytes containing fluorine, a binder or graphene compound can be used. The configuration may be such that it clings to or holds the material. By using this configuration, electrolysis It is possible to maintain a state in which the viscosity of the substance is reduced, or in other words, to maintain a fluid state of the electrolyte. This can improve the reliability of secondary batteries. DFEC with two fluorine atoms F4EC, which has four fluorine bonds, has lower viscosity compared to FEC, which has one fluorine bond. Furthermore, it is very fluid, and the coordination bond with lithium weakens. Therefore, the active material particles have high viscosity. This reduces the adhesion of decomposition products to the active material particles. If this happens, or if it clings to the active material particles, lithium ions will have difficulty moving at the interface of the active material particles. When an electrolyte containing ions is solvated, it causes a reaction on the surface of the active material (positive electrode active material or negative electrode active material). The formation of decomposition products is mitigated. Furthermore, by using an electrolyte containing fluorine, the decomposition process is reduced. By preventing substances from adhering to the surface, the formation and growth of dendrites can be prevented.

[0211] Another characteristic is that it uses electrolytes containing fluorine as its main component. The electrolyte content is 5% by volume or more, 10% by volume or more, preferably 30% by volume or more, up to 100 volumes. It should be less than or equal to %.

[0212] In this specification, the main component of the electrolyte is defined as 5% or more by volume of the total electrolyte of the secondary battery. This refers to the fact that... Also, the term "more than 5 volume percent of the total electrolyte of the secondary battery" here refers to the secondary battery... This refers to the proportion of the total electrolyte measured during manufacturing. It also refers to the proportion of the electrolyte after the secondary battery is manufactured. When decomposing the electrolyte, quantify the proportion of each type of electrolyte present. It is difficult to determine whether a particular organic compound makes up 5% or more of the total electrolyte by volume. It can be determined.

[0213] By using an electrolyte containing fluorine, a wide temperature range is achieved, specifically, from -40°C upwards to 15°C. It is possible to realize a secondary battery that can operate at temperatures below 0°C, preferably between -40°C and 85°C. Cut.

[0214] Furthermore, the electrolytes include vinylene carbonate, propanesultone (PS), and tert-butyl. Benzene (TBB), lithium bis(oxalate)borate (LiBOB), and also sucrose Additives such as dinitrile compounds like cinonitrile and adiponitrile may be added. The concentration of the additive should be, for example, 0.1% by volume or more and less than 5% by volume relative to the total electrolyte.

[0215] In addition to the above, electrolytes include γ-butyrolactone, acetonitrile, dimethoxyethane, It may contain one or more aprotic organic solvents such as tetrahydrofuran.

[0216] Furthermore, the presence of a polymer material in which the electrolyte gels enhances safety against leakage, etc. Okay. Typical examples of polymer materials that gel include silicone gel, acrylic gel, and acrylic gel. Lilonitrile gel, polyethylene oxide gel, polypropylene oxide gel, Examples include gels made from fluorine-based polymers.

[0217] Examples of polymer materials include polyalkylenes such as polyethylene oxide (PEO). Polymers having an oxide structure, PVDF, and polyacrylonitrile, etc., and the Copolymers containing these can be used. For example, PVDF and hexafluoropropylene PVDF-HFP, a copolymer of (HFP), can be used. The polymer may have a porous structure.

[0218] Furthermore, the above configuration is an example of a secondary battery using a liquid electrolyte, but it is not particularly limited to such batteries. For example, it is also possible to fabricate semi-solid-state batteries and all-solid-state batteries.

[0219] In this specification, the positive electrode applies to both secondary batteries using a liquid electrolyte and semi-solid batteries. The layer placed between the negative electrode and the negative electrode will be called the electrolyte layer. The electrolyte layer of a semi-solid battery is formed by film deposition. This can be described as a formed layer, and can be distinguished from a liquid electrolyte layer.

[0220] Furthermore, in this specification, a semi-solid battery means that at least one of the electrolyte layer, positive electrode, and negative electrode is This refers to a battery containing semi-solid materials. Here, "semi-solid" means that the ratio of solid material to solid material is 50%. That is not what it means. A semi-solid is a solid that possesses the properties of a solid, such as having little volume change, but is flexible. This means that it also possesses some properties similar to those of a liquid, such as being liquid. For example, a single material or multiple materials can be used. It may also be a substance that has been impregnated into the body material.

[0221] Furthermore, in this specification, a polymer electrolyte secondary battery is defined as having an electrolyte layer between the positive and negative electrodes. This refers to a secondary battery containing a polymer. Polymer electrolyte secondary batteries are dry (or intrinsic) polymer batteries. This includes polymer electrolyte batteries and polymer gel electrolyte batteries. Also includes polymer electrolyte secondary batteries. This could also be called a semi-solid battery.

[0222] When a semi-solid battery is made using the negative electrode according to one aspect of the present invention, the semi-solid battery has a charge / discharge capacity. It can be used to create a large secondary battery. Furthermore, it can be used to create a semi-solid battery with a high charge / discharge voltage. This makes it possible to realize safe or reliable semi-solid batteries.

[0223] Here, using Figure 7, we show an example of how to fabricate a semi-solid battery.

[0224] Figure 7 is a schematic cross-sectional view of a secondary battery according to one embodiment of the present invention. The secondary battery according to one embodiment of the present invention is negative It has an electrode 570a and a positive electrode 570b. The negative electrode 570a is a negative electrode current collector 571a and a negative electrode It includes at least a negative electrode active material layer 572a formed in contact with the current collector 571a, and a positive electrode 570 b is the positive electrode current collector 571b and the positive electrode active material layer 57 formed in contact with the positive electrode current collector 571b. It contains at least 2b. The secondary battery also contains electrolyte 57 between the negative electrode 570a and the positive electrode 570b. It has 6.

[0225] Electrolyte 576 comprises a lithium-ion conductive polymer and a lithium salt.

[0226] In this specification, a lithium-ion conductive polymer refers to a cation conductive polymer such as lithium. It is a polymer that has properties. More specifically, it is a polymer having polar groups to which cations can coordinate. It is a compound. Polar groups include ether groups, ester groups, nitrile groups, and carbonyl groups. It is preferable that the material contains siloxanes, etc.

[0227] Examples of lithium-ion conductive polymers include polyethylene oxide (PEO), Derivatives having polyethylene oxide as the main chain, polypropylene oxide, polyacrylic Polymethacrylates, polysyl esters, polysiloxanes, polyphosphazenes, etc. are used. It is possible to be there.

[0228] The lithium-ion conductive polymer may be branched or crosslinked. It may also be a polymer. The molecular weight is preferably, for example, 10,000 or more, and preferably 100,000 or more. It is preferable to have a certain state.

[0229] Lithium-ion conductive polymers exhibit partial motion (also called segmental motion) of polymer chains. Lithium ions move while changing the polar groups with which they interact. For example, PEO Then, the lithium ions change the oxygen they interact with through the segmental motion of the ether chain. It moves. The temperature is close to the melting or softening point of the lithium-ion conductive polymer, or When the temperature is high, the crystalline region dissolves and the amorphous region increases, and the movement of the ether chains becomes more active. Therefore, the ionic conductivity increases. For this reason, PEO is used as a lithium ion conductive polymer. When using this product, it is preferable to perform charging and discharging at temperatures above 60°C.

[0230] Shannon's ionic radius (Shannon et al., Acta A 32(19) According to 76) 751.), the radius of a monovalent lithium ion is 0.590 Å when it is four-coordinate. The Å length is 0.76 Å for 6-coordinate systems and 0.92 Å for 8-coordinate systems. Also, half of a divalent oxygen ion The diameter is 1.35 Å for 2-coordinate, 1.36 Å for 3-coordinate, 1.38 Å for 4-coordinate, and 6 The conductivity is 1.40 Å for coordinated lithium ions and 1.42 Å for 8-coordinate lithium ions. The distance between polar groups in a polymer chain is determined by the lithium ionic radius while maintaining the ionic radius as described above. It is preferable that the distance is greater than the distance at which the ions and anions of the polar groups can exist stably. Furthermore, it is preferable that the distance is such that sufficient interaction occurs between the lithium ion and the polar group. However, as mentioned above, segmented motion occurs, so it is not always necessary to maintain a constant distance. No. It just needs to be an appropriate distance for the lithium ions to pass through.

[0231] Furthermore, lithium salts include, for example, lithium along with phosphorus, fluorine, nitrogen, sulfur, oxygen, Having at least one of chlorine, arsenic, boron, aluminum, bromine, and iodine. Compounds can be used. For example, LiPF6, LiN(FSO2)2(lithium bicarbonate). Su(fluorosulfonyl)imide, LiFSI, LiClO4, LiAsF6, LiB F4, LiAlCl4, LiSCN, LiBr, LiI, Li2SO4, Li2B 10 C l 10 Li2B 12 Cl 12 , LiCF3SO3, LiC4F9SO3, LiC(CF 3SO2)3, LiC(C2F5SO2)3, LiN(CF3SO2)2, LiN(C4 F9SO2)(CF3SO2), LiN(C2F5SO2)2, Lithium Bis(Oxal) We entrust the handling of one or more lithium salts such as (LiBOB) borate. It can be used in combinations and ratios of intent.

[0232] In particular, using LiFSI is preferable because it provides good low-temperature characteristics. TFSA is less reactive with water compared to LiPF6, etc. Therefore, LiFSI is used in electrolysis. This facilitates control of the dew point when fabricating the electrode and electrolyte layers. For example, by minimizing moisture content. In addition to dry rooms with inert atmospheres such as argon and controlled dew points, as well as ordinary large It can be handled even in an air-filled environment. Therefore, productivity is improved, which is desirable. Also, LiFSI Furthermore, using a highly dissociative and plasticizing Li salt such as LiTFSA is preferable to using ether. When using lithium conduction that utilizes the segmental motion of the chain, it can be used over a wide temperature range. It is particularly preferable.

[0233] Furthermore, in this specification, a binder is used to bind active material, conductive material, etc., onto a current collector. This refers to polymer compounds that are mixed together. For example, polyvinylidene fluoride (PVDF), styrene Wyn-butadiene rubber (SBR), styrene-isoprene-styrene rubber, butadiene rubber Rubber materials such as ethylene-propylene-diene copolymers, fluororubber, and polystyrene Polyvinyl chloride, polytetrafluoroethylene, polyethylene, polypropylene, poly This refers to materials such as isobutylene and ethylene propylene diene polymers.

[0234] Since lithium-ion conductive polymers are polymer compounds, they must be thoroughly mixed before being used in the active material layer. This makes it possible to bond the active material and conductive material onto the current collector. Electrodes can be fabricated without using binders. Binders are materials that do not contribute to the charge-discharge reaction. Therefore, the less binder there is, the more materials that contribute to charging and discharging, such as active materials and electrolytes. Yes, it is possible. Therefore, it is possible to create a secondary battery with improved discharge capacity or cycle characteristics. ru.

[0235] By having little to no organic solvents, it is possible to create a secondary battery that is less likely to ignite or burn. This is preferable as it improves safety. Also, the electrolyte layer 576 is free of organic solvents or very If the electrolyte layer is small, it will have sufficient strength even without a separator, and the positive and negative electrodes will be electrically charged. It is possible to insulate it by gas. Since a separator is not required, it is a highly productive secondary power supply. It can be made into a pond. If the electrolyte 576 is an electrolyte layer having an inorganic filler, Furthermore, the strength is increased, making it possible to create a rechargeable battery with higher safety.

[0236] To make electrolyte 576 an electrolyte layer with little or no organic solvent, It is preferable that it be dried. In this specification, it is preferable that it be dried under reduced pressure at 90°C for 1 hour. If the weight change of the electrolyte layer is within 5%, it is considered to be sufficiently dried. ru.

[0237] Furthermore, the lithium-ion conductive polymer, lithium salt, binder and the secondary battery contain Nuclear magnetic resonance (NMR), for example, can be used to identify materials such as additives. Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), time-of-flight secondary ion mass spectrometry Methods of analysis (TOF-SIMS), gas chromatography-mass spectrometry (GC / MS), pyrolysis gas Chromatography-mass spectrometry (Py-GC / MS), liquid chromatography-mass spectrometry ( The results of analyses such as LC / MS may also be used as a basis for judgment. The active material layer is suspended in a solvent and It is preferable to separate the substance from other materials before subjecting them to analysis such as NMR.

[0238] Furthermore, in each of the above configurations, a solid electrolyte material is added to the negative electrode to improve flame retardancy. It is also possible to do so. It is preferable to use an oxide-based solid electrolyte as the solid electrolyte material.

[0239] Examples of oxide-based solid electrolytes include LiPON, Li2O, Li2CO3, and Li2MoO4. , Li3PO4, Li3VO4, Li4SiO4, LLT(La 2 / 3-x Li 3x Ti O3), LLZ(Li7La3Zr2O 12 ) and lithium complex oxides and lithium oxides The materials mentioned are:

[0240] LLZ is a garnet-type oxide containing Li, La, and Zr, as well as Al, Ga, and This may be a compound containing Ta.

[0241] Furthermore, polymer-based solid electrolytic materials such as PEO (polyethylene oxide) formed by coating methods, etc., are also used. A quality may be used. Such polymeric solid electrolytes can also function as binders. Therefore, when using polymer-based solid electrolytes, the number of electrode components can be reduced, and manufacturing costs can be lowered. It can also be reduced.

[0242] This embodiment can be used in appropriate combination with other embodiments.

[0243] (Embodiment 2) This embodiment describes an example of a secondary battery according to one aspect of the present invention.

[0244] <Example of a secondary battery configuration> The following explanation uses a secondary battery, in which the positive electrode, negative electrode, and electrolyte are enclosed in an outer casing, as an example. do.

[0245] [Negative electrode] As the negative electrode, the negative electrode shown in the previous embodiment can be used.

[0246] [Current collector] The positive electrode current collector and negative electrode current collector can be made from stainless steel, gold, platinum, zinc, iron, copper, or aluminum. Metals such as um, titanium, and their alloys, which have high conductivity and are carriers such as lithium Materials that do not alloy with ions can be used. Also, silicon, titanium, neodymium, and s Aluminum alloys to which elements that improve heat resistance, such as candium and molybdenum, have been added. It can be used. Furthermore, it can be formed with a metallic element that reacts with silicon to form a silicide. It may also be the case that, as a metallic element that reacts with silicon to form a silicide, zirconium, Titanium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten Examples include cellulose, cobalt, and nickel. Current collectors come in sheet, mesh, perforated metal, and other forms. Shapes such as bonded metal can be used as appropriate. The current collector has a thickness of 10 μm or more. It is best to use particles with a size of 30 μm or less.

[0247] Furthermore, it is preferable to use a material for the negative electrode current collector that does not alloy with carrier ions such as lithium. It seems so.

[0248] As a current collector, a titanium compound may be provided by laminating it on the metal element shown above. Titanium As the compound, for example, titanium nitride, titanium oxide, titanium nitride in which part of nitrogen is substituted with oxygen, titanium oxide in which part of oxygen is substituted with nitrogen, and titanium oxynitride (TiO x N y , where 0 < x < 2 and 0 < y < 1), can be selected singly or two or more of them can be mixed or laminated and used. Among them, titanium nitride is particularly preferable because it has high conductivity and a high function of suppressing oxidation. By providing the titanium compound on the surface of the current collector, for example, the reaction between the material and the metal in the active material layer formed on the current collector is suppressed. When the active material layer contains a compound having oxygen, the oxidation reaction between the metal element and oxygen can be suppressed. For example, when aluminum is used as the current collector and the active material layer is formed using graphene oxide described later, there is concern about the oxidation reaction between the oxygen in graphene oxide and aluminum. In such a case, by providing a titanium compound on aluminum, the oxidation reaction between the current collector and graphene oxide can be suppressed.

[0249] 〔Positive electrode〕 The positive electrode has a positive electrode active material layer and a positive electrode current collector. The positive electrode active material layer has a positive electrode active material and may have a conductive material and a binder. As the positive electrode active material, the positive electrode active material shown in the previous embodiment can be used.

[0250] As the conductive material and binder that the positive electrode active material layer can have, the same materials as the conductive material and binder that the negative electrode active material layer can have can be used.

[0251] 〔Separator〕 A separator is placed between the positive and negative electrodes. Examples of separators include paper. Fibers, nonwoven fabrics, glass fibers, ceramics, or nylon (polycellulose) containing cellulose. Riamide, Vinylon (polyvinyl alcohol-based fiber), Polyester, Acrylic, Poly Synthetic fibers made from olefins, polyurethanes, etc., can be used. The separator is processed into a bag shape and positioned to enclose either the positive or negative electrode. preferable.

[0252] The separator has pores with a diameter of approximately 20 nm, preferably with a diameter of 6.5 nm or larger. It is a porous material having pores, more preferably pores with a diameter of at least 2 nm. In the case of semi-solid secondary batteries, the separator can be omitted.

[0253] The separator may have a multilayer structure. For example, an organic material such as polypropylene or polyethylene. The material film contains ceramic-based materials, fluorine-based materials, polyamide-based materials, or a combination thereof. Mixtures and other materials can be coated onto it. Examples of ceramic materials include aluminum oxide. Aluminum particles, silicon oxide particles, etc. can be used. Examples of fluorine-based materials include PVDF, polytetrafluoroethylene, etc. can be used. Polyamide materials and For example, nylon, aramid (meta-aramid, para-aramid), etc. can be used. It is possible.

[0254] Coating with ceramic materials improves oxidation resistance, thus preventing separation during high-voltage charging and discharging. This can suppress the degradation of the data and improve the reliability of secondary batteries. Furthermore, fluorine-based materials... Coating the electrode makes it easier for the separator and electrode to adhere to each other, which can improve the output characteristics. Coating with polyamide materials, especially aramid, improves heat resistance, thus improving the heat resistance of secondary batteries. Safety can be improved.

[0255] For example, a mixture of aluminum oxide and aramid material is applied to both sides of a polypropylene film. It may also be done by applying aluminum oxide to the surface of the polypropylene film that is in contact with the positive electrode. A mixed material of um and aramid may be coated, and a fluorine-based material may be coated on the surface in contact with the negative electrode. .

[0256] Using a multilayer separator ensures the safety of secondary batteries even with a thin overall separator. Because this can be maintained, the capacity per unit volume of the secondary battery can be increased.

[0257] [Exterior] The outer casing of a secondary battery can be made of, for example, metal materials such as aluminum and resin materials. A film-like outer covering can be used. For example, polyethylene, polypropylene, polycarbonate, ionomer, polya On a film made of materials such as mid, aluminum, stainless steel, copper, nickel, etc., which have excellent flexibility A thin metal film is provided, and a polyamide resin is used as the outer surface of the exterior body on top of the thin metal film. A three-layer film with an insulating synthetic resin film, such as an ester resin, can be used. Furthermore, it is preferable to use a fluororesin film as the film. Mu has high stability against acids, alkalis, organic solvents, etc., and is not associated with side effects from reactions in secondary batteries, etc. By suppressing corrosion and other issues, a superior secondary battery can be realized. Fluororesin film and PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkaldehyde) (a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether), FE P(perfluoroethylenepropene copolymer: tetrafluoroethylene and hexafluoroethylene) Polypropylene copolymer, ETFE (ethylene tetrafluoroethylene copolymer: tetrafluoroethylene copolymer) Examples include copolymers of trafluoroethylene and ethylene.

[0258] This embodiment can be used in appropriate combination with other embodiments.

[0259] (Embodiment 3) In this embodiment, the positive electrode or the positive electrode manufactured by the manufacturing method described in the previous embodiment is used. This section describes examples of various shapes of secondary batteries that have a negative electrode.

[0260] [Coin-type rechargeable battery] An example of a coin-type rechargeable battery is described below. Figure 8A shows a coin-type (single-layer flattened) rechargeable battery. Figure 8B is an external view of the battery, and Figure 8C is a cross-sectional view thereof. Type N rechargeable batteries are mainly used in small electronic devices.

[0261] In Figure 8A, the overlapping of the components (up / down relationship and positional relationship) is shown for clarity. The diagrams are schematic representations. Therefore, Figure 8A and Figure 8B are not intended to be perfectly identical corresponding diagrams. stomach.

[0262] Figure 8A shows the positive electrode 304, separator 310, negative electrode 307, spacer 322, and washer. -312 is stacked. These are sealed with negative electrode container 302 and positive electrode container 301. In 8A, the gasket for sealing is not shown. Spacer 322, washer 312 protects the inside or position within the can when crimping the positive electrode can 301 and the negative electrode can 302. They are used for fixing. Spacer 322 and washer 312 are made of stainless steel or Use insulating materials.

[0263] The positive electrode 304 is a laminated structure in which a positive electrode active material layer 306 is formed on a positive electrode current collector 305. ru.

[0264] To prevent a short circuit between the positive and negative electrodes, a separator 310 and a ring-shaped insulator 313 are connected to the positive electrode 30 They are positioned to cover the sides and top of 4, respectively. Separator 310 is positioned from positive electrode 304 It also has a large floor area.

[0265] Figure 8B is a perspective view of the completed coin-type rechargeable battery.

[0266] The coin-type rechargeable battery 300 consists of a positive electrode casing 301 which also serves as the positive electrode terminal and a negative electrode casing which also serves as the negative electrode terminal. The can 302 is insulated and sealed with a gasket 303 made of polypropylene or the like. The positive electrode 304 consists of a positive electrode current collector 305 and a positive electrode active material layer 30 provided in contact with it. It is formed by 6. The negative electrode 307 is provided with the negative electrode current collector 308 and is set to be in contact with it. It is formed by the negative electrode active material layer 309. Furthermore, the negative electrode 307 is not limited to a laminated structure. Alternatively, lithium metal foil or a lithium-aluminum alloy foil may be used.

[0267] Furthermore, the positive electrode 304 and negative electrode 307 used in the coin-type secondary battery 300 are each active The material layer only needs to be formed on one side.

[0268] The positive electrode can 301 and negative electrode can 302 contain nickel and aluminum, which are corrosion-resistant to the electrolyte. Metals such as titanium, or alloys thereof, or alloys of these with other metals (for example, steel Stainless steel, etc. can be used. In addition, nickel and to prevent corrosion by electrolytes, It is preferable to coat it with aluminum or the like. The positive electrode can 301 is a positive electrode 304 and a negative electrode can 30 Terminal 2 is electrically connected to the negative electrode 307.

[0269] These negative electrode 307, positive electrode 304, and separator 310 are immersed in the electrolyte, as shown in Figure 8C. As shown, with the positive electrode can 301 at the bottom, the positive electrode 304, separator 310, negative electrode 307, and negative electrode can 3 The 02 components are stacked in this order, and the positive electrode can 301 and the negative electrode can 302 are crimped together via the gasket 303. This process is used to manufacture coin-type rechargeable batteries 300.

[0270] By using a rechargeable battery, it achieves high capacity, high charge / discharge capacity, and excellent cycle characteristics. This can be a coin-type rechargeable battery 300.

[0271] [Cylindrical rechargeable battery] An example of a cylindrical secondary battery will be explained with reference to Figure 9A. The cylindrical secondary battery 616 is As shown in Figure 9A, the top surface has a positive electrode cap (battery cover) 601, and the sides and bottom have an electric electrode It has a battery container (outer container) 602. The battery container (outer container) 602 is made of a metal material and is transparent. It has excellent water barrier and gas barrier properties. These positive electrode cap 601 and battery can (outer The container (602) is insulated by the gasket (insulating packing) 610.

[0272] Figure 9B is a schematic diagram showing a cross-section of a cylindrical secondary battery. The rechargeable battery has a positive electrode cap (battery cover) 601 on the top surface, and a battery case (outer) on the sides and bottom. It has a battery can (outer can) 602. These positive electrode caps and battery can (outer can) 602 are separated by a gasket. It is insulated by a 610 (insulating packing).

[0273] Inside the hollow cylindrical battery can 602, there is a separator between the strip-shaped positive electrode 604 and the negative electrode 606. A battery element is provided, wound with a 605 in between. Although not shown in the diagram, the battery element is It is wound around the center pin. The battery can 602 is closed at one end and open at the other end. The battery can 602 contains nickel, aluminum, and titanium, which are corrosion-resistant to the electrolyte. Metals such as stainless steel, or alloys thereof, and alloys of these with other metals (for example, stainless steel) (etc.) can be used. In addition, nickel and aluminum can be used to prevent corrosion by electrolytes. It is preferable to coat the battery can 602 with nium or the like. Inside the battery can 602, the positive electrode The battery element, in which the negative electrode and separator are wound, is surrounded by a pair of opposing insulating plates 608, 609 It is sandwiched between them. Also, the inside of the battery can 602 in which the battery element is provided contains an electrolyte (shown in the figure). (It is not injected.) The electrolyte can be the same as that used in coin-type rechargeable batteries. Cut.

[0274] Since the positive and negative electrodes used in cylindrical storage batteries are wound, active material is formed on both sides of the current collector. It is preferable to do so.

[0275] By using the negative electrode obtained in Embodiment 1, a high capacity and high charge / discharge capacity are achieved, This allows for a cylindrical secondary battery 616 with excellent cycle characteristics.

[0276] The positive terminal (positive current collector lead) 603 is connected to the positive terminal 604, and the negative terminal 606 is connected to the negative terminal The child (negative current collector lead) 607 is connected. The positive terminal 603 and the negative terminal 607 are, Metal materials such as aluminum can be used. The positive terminal 603 is connected to the safety valve mechanism 6 13. The negative terminals 607 are resistance-welded to the bottom of the battery can 602. Safety valve mechanism 61 3 is a PTC element (Positive Temperature Coefficient). The positive electrode cap 601 is electrically connected via t)611. The safety valve mechanism 613 is When the internal pressure of the battery rises above a predetermined threshold, the electrical current between the positive electrode cap 601 and the positive electrode 604 This disconnects the gas connection. Furthermore, the PTC element 611 has resistance when the temperature rises. This is a thermal resistance element with increased resistance, which limits the current flow and prevents abnormal heat generation. The PTC element uses barium titanate (BaTiO3) semiconductor ceramics. The following can be used.

[0277] Figure 9C shows an example of an energy storage system 615. The energy storage system 615 consists of multiple secondary batteries 61 It has 6. The positive electrode of each secondary battery is in contact with a conductor 624 separated by an insulator 625. They are in contact and electrically connected. Conductor 624 is connected to control circuit 620 via wiring 623. They are electrically connected. Furthermore, the negative terminal of each secondary battery is controlled via wiring 626. It is electrically connected to circuit 620. The control circuit 620 performs charging and discharging operations. A control circuit and a protection circuit to prevent overcharging and / or over-discharging can be applied. Cut.

[0278] Figure 9D shows an example of the energy storage system 615. The energy storage system 615 consists of multiple secondary batteries 6 Having 16, multiple secondary batteries 616 are sandwiched between conductive plates 628 and 614. Multiple secondary batteries 616 are electrically connected to conductive plates 628 and 614 by wiring 627. It is connected to the following. Multiple secondary batteries 616 may be connected in parallel or in series. They may be connected in parallel and then in series. Multiple secondary batteries By configuring a power storage system 615 having 616, a large amount of power can be extracted. ru.

[0279] Multiple secondary batteries 616 may be connected in parallel and then further connected in series.

[0280] A temperature control device may be provided between multiple secondary batteries 616. When this occurs, the temperature control device cools the battery, and if the secondary battery 616 is too cold, the temperature control device will turn off. The control device can heat the system. Therefore, the performance of the energy storage system 615 is affected by the ambient temperature. It becomes less susceptible to resonance.

[0281] Furthermore, in Figure 9D, the energy storage system 615 has wiring 621 and wiring 6 connected to the control circuit 620. It is electrically connected via 22. Wiring 621 is connected to multiple secondary power via conductive plate 628. The wiring 622 is connected to the positive terminal of the battery 616, and via the conductive plate 614 to the negative terminals of multiple secondary batteries 616. They are electrically connected to each other.

[0282] [Other structural examples of secondary batteries] Examples of secondary battery structures will be explained using Figures 10 and 11.

[0283] The secondary battery 913 shown in Figure 10A has terminals 951 and 952 inside the housing 930. It has a wound body 950. The wound body 950 is immersed in an electrolyte inside the housing 930. Terminal 952 is in contact with the housing 930, and terminal 951 is in contact with the housing by using an insulating material or the like. It is not in contact with 930. Note that in Figure 10A, for convenience, the housing 930 is shown separately. However, in reality, the wound body 950 is covered by the housing 930, and terminals 951 and 952 are covered by the housing. It extends outside the body 930. The housing 930 is made of a metal material (for example, aluminum). ) or resin materials can be used.

[0284] Furthermore, as shown in Figure 10B, the housing 930 shown in Figure 10A is formed from multiple materials. This is also acceptable. For example, the secondary battery 913 shown in Figure 10B has housings 930a and 930b attached to it. The components are joined together, and the winding body 950 is provided in the area enclosed by the housing 930a and housing 930b. It is being done.

[0285] For the enclosure 930a, insulating materials such as organic resins can be used. In particular, the antenna By using a material such as organic resin on the surface where the na is formed, the electric field produced by the secondary battery 913 is created. This can suppress shielding. If the shielding of the electric field by the housing 930a is small, the housing 930a An antenna may be installed inside. For the housing 930b, for example, a metal material may be used. It is possible.

[0286] Furthermore, the structure of the wound body 950 is shown in Figure 10C. The wound body 950 is connected to the negative electrode 931 and It has a positive electrode 932 and a separator 933. The wound body 950 has a separator 933. The negative electrode 931 and the positive electrode 932 are stacked on top of each other, and the stacked sheet is rolled up. It is a rotating body. Furthermore, the stacking of the negative electrode 931, the positive electrode 932, and the separator 933 is further You can stack multiple of them.

[0287] Alternatively, the secondary battery 913 may have a wound body 950a as shown in Figure 11. Figure 1 The wound body 950a shown in 1A has a negative electrode 931, a positive electrode 932, and a separator 933. The negative electrode 931 has a negative electrode active material layer 931a. The positive electrode 932 has a positive electrode active material layer 932a. It holds.

[0288] By using a fluorine-containing electrolyte in the negative electrode 931, the charge / discharge capacity is high, and cycling This allows for the creation of a secondary battery 913 with excellent performance characteristics.

[0289] The separator 933 has a wider width than the negative electrode active material layer 931a and the positive electrode active material layer 932a. It has and is wound so as to overlap with the negative electrode active material layer 931a and the positive electrode active material layer 932a. It is. Also, the fact that the negative electrode active material layer 931a is wider than the positive electrode active material layer 932a is a safety feature. It is preferable in this respect. Furthermore, a coiled body 950a of this shape is preferable because it is safe and productive. stomach.

[0290] As shown in Figures 11A and 11B, the negative electrode 931 is electrically connected to terminal 951. Terminal 951 is electrically connected to terminal 911a. Also, the positive terminal 932 is electrically connected to terminal 952. It is connected to terminal 952. Terminal 952 is electrically connected to terminal 911b.

[0291] As shown in Figure 11C, the coiled body 950a and the electrolyte are covered by the housing 930, secondary This becomes the battery 913. It is preferable to provide a safety valve, overcurrent protection element, etc., in the housing 930. The safety valve opens when the internal pressure of the housing 930 reaches a predetermined level, in order to prevent the battery from rupturing. It is a valve that does so.

[0292] As shown in Figure 11B, the secondary battery 913 may have multiple windings 950a. By using a larger number of wound bodies 950a, a secondary battery 913 with a larger charge / discharge capacity can be obtained. This is possible. Other elements of the secondary battery 913 shown in Figures 11A and 11B are shown in Figures 10A to 11B. The description of secondary battery 913 shown in 10C can be taken into consideration.

[0293] <Laminated rechargeable battery> Next, regarding an example of a laminate-type secondary battery, an example of its external appearance is shown in Figures 12A and 12B. Figures 12A and 12B show the positive electrode 503, negative electrode 506, separator 507, and outer casing 5. 09, It has a positive lead electrode 510 and a negative lead electrode 511.

[0294] Figure 13A shows the external view of the positive electrode 503 and the negative electrode 506. The positive electrode 503 is the positive electrode current collector 501 The positive electrode has a positive electrode active material layer 502 which is formed on the surface of the positive electrode current collector 501. 03 has a region where the positive electrode current collector 501 is partially exposed (hereinafter referred to as the tab region). Negative electrode 5 06 has a negative electrode current collector 504, and the negative electrode active material layer 505 is formed on the surface of the negative electrode current collector 504. Furthermore, the negative electrode 506 is the region where the negative electrode current collector 504 is partially exposed, i.e., the tab region. It has the following characteristics. The area and shape of the tab regions of the positive and negative electrodes are not limited to the example shown in Figure 13A. I can't.

[0295] <Method for manufacturing laminated rechargeable batteries> Here, an example of a method for manufacturing a laminate-type secondary battery, as shown in Figure 12A, is presented. This will be explained using Figures 13B and 13C.

[0296] First, the negative electrode 506, separator 507, and positive electrode 503 are stacked. They are stacked as shown in Figure 13B. The negative electrode 506, separator 507, and positive electrode 503 are shown. Here, there are 5 sets of negative electrodes and 4 sets of positive electrodes. An example of its use in combination is shown. It can also be called a laminate consisting of a negative electrode, a separator, and a positive electrode. Next, positive electrode 5 Bonding of tab regions 03 and bonding of positive lead electrode 510 to the tab region of the outermost positive electrode. Perform the following. For joining, ultrasonic welding, for example, may be used. Similarly, the tab area of ​​the negative electrode 506. The components are joined together, and the negative electrode lead electrode 511 is joined to the tab region of the outermost negative electrode.

[0297] Next, the negative electrode 506, separator 507, and positive electrode 503 are placed on the outer casing 509.

[0298] Next, as shown in Figure 13C, fold the outer casing 509 at the part indicated by the dashed line. The outer periphery of the exterior body 509 is joined. For joining, for example, heat compression bonding may be used. At this time, To allow for the later insertion of electrolyte 508, a portion (or one side) of the outer casing 509 is attached. A non-contact area (hereinafter referred to as the inlet) is provided. The outer casing 509 has water permeability barrier properties and gas It is preferable to use a film that has excellent barrier properties. Also, the outer casing 509 is By using a laminated structure and making one of the intermediate layers a metal foil (for example, aluminum foil), high transparency is achieved. It can achieve both water barrier and gas barrier properties.

[0299] Next, the electrolyte 508 (not shown) is introduced through the inlet provided in the outer casing 509 into the outer casing Introduce into the inside of 509. Introduce electrolyte 508 under reduced pressure or inert atmosphere. It is preferable to do so. And finally, the inlet is joined. In this way, the laminate It is possible to manufacture a secondary battery of type 500.

[0300] The negative electrode structure obtained in Embodiment 1, i.e., the graphene compound is a particle having silicon, A material that has been mixed and heated with a halogen-containing material, an oxygen-containing material, and a carbon-containing material is tightly coated By using the attached electrode as the negative electrode 506, high capacity and high charge / discharge capacity are achieved, This allows for the creation of a secondary battery 500 with excellent cycle characteristics.

[0301] This embodiment can be used in appropriate combination with other embodiments.

[0302] (Embodiment 4) This embodiment is a different example from Figure 9D, which is a cylindrical secondary battery. Using Figure 14C... This section shows an example of its application to electric vehicles (EVs).

[0303] Electric vehicles have a first battery 1301a, 130 as the main secondary battery for propulsion. 1b and a second battery that supplies power to inverter 1312 for starting motor 1304 Battery 1311 is installed. The second battery 1311 is the cranking battery (starter) Also called a secondary battery. The second battery 1311 is high output and In that case, a large capacity is not so necessary, and the capacity of the second battery 1311 is the same as the first battery It is smaller compared to Ri1301a and 1301b.

[0304] The internal structure of the first battery 1301a may be the wound type shown in Figure 10A, The stacked type shown in Figures 12A and 12B may also be used.

[0305] In this embodiment, the first batteries 1301a and 1301b are connected in parallel. The example shown is that three or more can be connected in parallel. Also, the first battery 1301a If sufficient power can be stored, the first battery 1301b is not necessary. By configuring a battery pack that includes a secondary battery, it is possible to extract a large amount of power. Multiple rechargeable batteries may be connected in parallel, in series, or in parallel. After being connected, they may be further connected in series. Multiple rechargeable batteries are also called a battery pack.

[0306] Furthermore, in the case of a rechargeable battery installed in a vehicle, a tool is used to interrupt the power supply from multiple rechargeable batteries. It has a service plug or circuit breaker that can shut off high voltage without being used, It is provided in battery 1301a.

[0307] Furthermore, the power from the first batteries 1301a and 1301b is mainly used to rotate the motor 1304. It is used to power 42V automotive components (electric power) via the DC-DC circuit 1306. It supplies power to the steering wheel (1307, heater 1308, defogger 1309, etc.). Even when the rear motor 1317 is present, the first battery 1301a is connected to the rear motor 13 It is used to rotate 17.

[0308] Furthermore, the second battery 1311 is connected to 14V automotive components via the DC-DC circuit 1310. (Supplies power to audio 1313, power windows 1314, lights 1315, etc.) To give.

[0309] Furthermore, the first battery 1301a will be explained using Figure 14A.

[0310] Figure 14A shows an example where nine rectangular rechargeable batteries 1300 are combined into a single battery pack 1415. It also shows that nine rectangular rechargeable batteries 1300 are connected in series, with one electrode separated from the insulator. The first electrode is fixed with a fixing part 1413, and the second electrode is fixed with a fixing part 1414 made of an insulator. In this embodiment, an example is shown in which the battery is fixed with fixing parts 1413 and 1414. It may also be configured to house the vehicle in a container (also called an enclosure). Since it is expected that vibration or shaking will be applied, the fixing parts 1413, 1414 Furthermore, it is preferable to secure multiple secondary batteries in a battery housing box or the like. The electrodes are electrically connected to the control circuit unit 1320 by wiring 1421. One electrode is electrically connected to the control circuit unit 1320 by wiring 1422.

[0311] Furthermore, the control circuit unit 1320 includes a memory circuit that includes a transistor using an oxide semiconductor. It may be used. A charge control circuit having a memory circuit including an oxide semiconductor transistor. A road or battery control system is called a BTOS (Battery operating system). In places where it is called tem, or Battery oxide semiconductor There is a match.

[0312] The control circuit unit 1320 detects the terminal voltage of the secondary battery and manages the charging and discharging state of the secondary battery. For example, to prevent overcharging, both the output transistor and the cutoff switch of the charging circuit are They can be turned off almost simultaneously.

[0313] Furthermore, Figure 14B shows an example of a block diagram of the battery pack 1415 shown in Figure 14A.

[0314] The control circuit unit 1320 includes at least a switch to prevent overcharging and a switch to prevent over-discharging. A switch unit 1324 including a switch, and a control circuit 1322 that controls the switch unit 1324. The control circuit unit 1320 has a voltage measuring unit for the first battery 1301a. The secondary battery has upper and lower voltage limits set, and the upper and lower limits of the external input current are also set. The upper limit of the output current to the unit is set. Within the range between the lower limit voltage and the upper limit voltage of the secondary battery. The enclosed area is within the recommended voltage range for use, and outside this range, the switch section 132 4 is activated and functions as a protection circuit. Also, the control circuit unit 1320 is connected to the switch unit 132 It can also be called a protection circuit because it controls 4 to prevent over-discharge and / or over-charge. When the control circuit 1322 detects a voltage that is likely to cause overcharging, the switch unit 1324 switches The current is interrupted by turning the switch to the OFF state. Furthermore, a PTC element is provided in the charge / discharge path. A function to interrupt the current in response to the rise in temperature may be provided. Also, the control circuit unit 1320 It has external terminals 1325 (+IN) and 1326 (-IN).

[0315] The switch section 1324 uses an n-channel transistor and a p-channel transistor. It can be constructed by combining the components. The switch section 1324 uses single-crystal silicon. Switches are not limited to those having Si transistors, but for example, those using Ge (germanium), S iGe (silicon germanium), GaAs (gallium arsenide), GaAlAs (gallium Aluminum arsenic, InP (indium phosphide), SiC (silicon carbide), Z nSe (zinc selenide), GaN (gallium nitride), GaOx (gallium oxide; x is 0) The switch section 1324 may be formed using a power transistor having a large real number (or similar). Furthermore, memory elements using OS transistors can be placed on circuits using Si transistors, etc. Because it can be freely arranged by stacking, integration can be easily achieved. Transistors can be manufactured using the same manufacturing equipment as Si transistors. Therefore, it can be manufactured at low cost. That is, an OS transistor is used on the switch section 1324. The control circuit unit 1320 can be stacked and integrated into a single chip. Since the volume occupied by the circuit section 1320 can be reduced, miniaturization becomes possible.

[0316] The first batteries, 1301a and 1301b, are primarily used to power 42V (high-voltage) in-vehicle equipment. The second battery 1311 supplies power to 14V (low-voltage) in-vehicle equipment. The second battery, 1311, is often a lead-acid battery because it is more cost-effective.

[0317] In this embodiment, both the first battery 1301a and the second battery 1311 are supplied with lithium An example using a um-ion secondary battery is shown. The second battery 1311 is a lead-acid battery, an all-solid-state battery. A pond or an electric double-layer capacitor may be used.

[0318] Furthermore, the regenerative energy from the rotation of the tire 1316 is transmitted to the motor 1 via the gear 1305. It is sent to 304, and the motor controller 1303 and battery controller 1302 The second battery 1311 is then charged via the control circuit unit 1321. The controller 1302 charges the first battery 1301a via the control circuit unit 1320. Alternatively, the first is transmitted from the battery controller 1302 via the control circuit unit 1320. The battery 1301b is charged. In order to efficiently charge the regenerative energy, the first It is desirable that batteries 1301a and 1301b are capable of rapid charging.

[0319] The battery controller 1302 controls the charging voltage of the first batteries 1301a and 1301b. The charging current and other parameters can be set. The battery controller 1302 uses By setting charging conditions according to the charging characteristics of the secondary battery, rapid charging can be achieved.

[0320] Also, although not shown in the diagram, when connecting to an external charger, the charger's outlet or The charger's connection cable is electrically connected to the battery controller 1302. Power supplied from the charger is sent to the first battery via the battery controller 1302. Charges 1301a and 1301b. Also, some chargers have a control circuit. Although the functions of the battery controller 1302 may not be used, to prevent overcharging... It is preferable to charge the first batteries 1301a and 1301b via the control circuit unit 1320. It seems so. Also, if the connection cable or the charger's connection cable has a control circuit. Yes, it exists. The control circuit unit 1320 is an ECU (Electronic Control Unit). It is sometimes called t). ECU is a control unit installed in electric vehicles. It connects to the ER Area Network. CAN is used as the in-vehicle LAN. It is one of the serial communication standards. Furthermore, an ECU includes a microcomputer. The ECU uses a CPU and a GPU.

[0321] Next, we will describe an example in which a secondary battery, which is one aspect of the present invention, is implemented in a vehicle, typically a transport vehicle. I will explain.

[0322] Furthermore, if the secondary battery shown in either Figure 9D or Figure 14A is installed in the vehicle, the hybrid Next, hybrid vehicles (HV), electric vehicles (EV), or plug-in hybrid vehicles (PHV), etc. This will enable the realization of next-generation clean energy vehicles, including agricultural machinery and electric-assist bicycles. Mopeds, motorcycles, electric wheelchairs, electric carts, small or large vessels, submarines, Aircraft such as fixed-wing aircraft or rotary-wing aircraft, rockets, artificial satellites, space probes, planetary probes, and more. Alternatively, secondary batteries can be installed in transport vehicles such as spacecraft. One aspect of the present invention The next battery can be a high-capacity secondary battery. Therefore, a secondary battery according to one embodiment of the present invention is It is suitable for miniaturization and weight reduction, and can be suitably used in transport vehicles.

[0323] Figures 15A to 15D illustrate a transport vehicle using one embodiment of the present invention. The automobile 2001 shown in 5A is an electric vehicle that uses an electric motor as a power source for driving. Alternatively, an electric motor and an engine can be appropriately selected and used as the power source for propulsion. It is a hybrid vehicle that is capable of doing so. When a secondary battery is installed in the vehicle, the secondary battery is Install in one or more locations. The automobile 2001 shown in Figure 15A has a battery pack 2200 The battery pack has a secondary battery module which connects multiple secondary batteries. It is preferable to have a charge control device that is electrically connected to the secondary battery module.

[0324] Furthermore, the automobile 2001 has a secondary battery that is plug-in or non It can be charged by receiving power from an external charging facility using a contact power supply method, etc. Regarding power supply, charging methods and connector specifications are based on CHAdeMO® or CHAdeMO®. This can be done appropriately using the prescribed method, such as a battery charger. It can be an external power source, or a household power source. For example, by using plug-in technology, external The power supply from this source can charge the battery storage device installed in the vehicle 2001. Electricity is generated by converting alternating current (AC) power to direct current (DC) power via a conversion device such as an AC / DC converter. It is possible.

[0325] Although not shown in the diagram, a power receiving device is mounted on the vehicle, and power is supplied wirelessly from a ground-based power transmission device. It can also be charged by supplying power. In this contactless power supply method, power transmission equipment is installed on the road or exterior wall. By incorporating this, charging can be performed not only when the vehicle is stopped but also while it is in motion. Power can be transmitted and received between two vehicles using a contact-to-power method. Solar panels may be installed on both exterior parts to charge the secondary battery while the vehicle is stopped and in motion. For contactless power supply like this, electromagnetic induction or magnetic resonance methods can be used. Cut.

[0326] Figure 15B shows a large transport vehicle equipped with an electrically controlled motor, as an example of a transport vehicle. This indicates 2002. The secondary battery module of the transport vehicle 2002 is, for example, 3.5V or higher. Four rechargeable batteries with a voltage of 0.7V or less are used as cell units, and 48 cells are connected in series to produce a maximum voltage of 170V. The voltage will be high. The number of secondary batteries that make up the secondary battery module of the battery pack 2201, etc. Aside from the differences, it has the same functions as Figure 15A, so I will omit the explanation.

[0327] Figure 15C shows, as an example, a large transport vehicle 2003 equipped with an electrically controlled motor. This indicates that the secondary battery module of the transport vehicle 2003 is, for example, 3.5V to 4.7V. The maximum voltage of 600V is obtained by connecting more than 100 of the secondary batteries shown below in series. Therefore, characteristic variation A secondary battery with a small power consumption is needed. This battery uses a structure in which a fluorine-containing electrolyte is contained within the negative electrode. By using secondary batteries, it is possible to manufacture secondary batteries with stable battery characteristics, From a storage perspective, it is possible to mass-produce at low cost. Also, the secondary power of the battery pack 2202 Aside from differences in the number of secondary batteries that make up the battery module, it has the same functions as Figure 15A. Since there are others, I will omit the explanation.

[0328] Figure 15D shows, as an example, an aircraft 2004 with a fuel-burning engine. The aircraft 2004 shown in Figure 15D is a type of transport vehicle because it has wheels for takeoff and landing. However, by connecting multiple rechargeable batteries, a rechargeable battery module is constructed, and the rechargeable battery module It has a battery pack 2203 that includes a battery and a charging control device.

[0329] The secondary battery module for the aircraft 2004, for example, consists of eight 4V secondary batteries connected in series. The maximum voltage is 32V. The secondary batteries that make up the secondary battery module of battery pack 2203. Aside from differences in the number of elements, it has the same functions as Figure 15A, so the explanation will be omitted.

[0330] This embodiment can be used in appropriate combination with other embodiments.

[0331] (Embodiment 5) In this embodiment, Figure 1 shows an example of implementing a secondary battery, which is one aspect of the present invention, in a building. This will be explained using 6A and Figure 16B.

[0332] The house shown in Figure 16A is an energy storage device 2612 having a secondary battery, which is one embodiment of the present invention. It has a solar panel 2610. The energy storage device 2612 is connected to the solar panel 2610 and wiring It is electrically connected via 2611, etc. Also, the energy storage device 2612 and the ground-mounted charging Device 2604 may be electrically connected. The power obtained from the solar panel 2610 is The energy storage device 2612 can be charged. Furthermore, the power stored in the energy storage device 2612 is... The secondary battery of the vehicle 2603 can be charged via the charging device 2604. The device 2612 is preferably installed in the underfloor space. This allows for more effective use of the space above the floor. Alternatively, the energy storage device 2612 is above the floor. It can also be installed in [location].

[0333] The electricity stored in the energy storage device 2612 is used to power other electronic devices in the house. This is possible. Therefore, even when power cannot be supplied from the commercial power source due to a power outage, this power By using the energy storage device 2612 according to one embodiment of the invention as an uninterruptible power supply, the use of electronic equipment is It becomes possible.

[0334] Figure 16B shows an example of an energy storage device 700 according to one aspect of the present invention. In the underfloor space 796 of the building 799, an energy storage device 791 according to one aspect of the present invention is installed. It is being done.

[0335] The energy storage device 791 is equipped with a control device 790, and the control device 790 is connected by wiring That is, the distribution board 703, the energy storage controller 705 (also called the control unit), and the display unit 706. It is electrically connected to router 709.

[0336] Power is supplied from the commercial power supply 701 to the distribution panel 703 via the service drop connection section 710. Furthermore, power is supplied to the distribution board 703 from the energy storage device 791 and the commercial power supply 701. The distribution board 703 receives the power and, via outlets (not shown), loads the general load 707. It also supplies power to the energy storage system load 708.

[0337] General load 707 is, for example, electrical equipment such as televisions and personal computers. The energy storage load 708 is, for example, an electrical appliance such as a microwave oven, refrigerator, and air conditioner. be.

[0338] The energy storage controller 705 includes a measurement unit 711, a prediction unit 712, and a planning unit 713. The measurement unit 711 measures the general load 707 and the energy storage during a day (for example, from 0:00 to 24:00). It has a function to measure the amount of electricity consumed by the system load 708. In addition, the measurement unit 711 has a function to measure the amount of energy stored. It has the function of measuring the amount of electricity used by device 791 and the amount of electricity supplied from the commercial power supply 701. It is also acceptable to do so. In addition, the prediction unit 712 predicts the general load 707 and the energy storage system load 70 during the day. Based on the amount of electricity consumed in 8, the general load 707 and the energy storage system load 708 during the next day It has a function to predict the amount of electricity demanded to be consumed. In addition, the planning unit 713 has a function to predict the forecasting unit 712 It has the function of planning the charging and discharging of the energy storage device 791 based on the predicted amount of electricity demand. .

[0339] The electricity consumed by the general load 707 and the energy storage system load 708 as measured by the measurement unit 711 The power level can be checked by the display unit 706. Also, via the router 709, This can also be confirmed in electrical equipment such as Levi and personal computers. Furthermore, via Router 709, mobile electronic devices such as smartphones and tablets can access the network. It can also be confirmed by the display unit 706, electrical equipment, and portable electronic terminals. The forecasting unit 712 also checks the predicted electricity demand for each time period (or hourly). It is possible.

[0340] This embodiment can be used in appropriate combination with other embodiments.

[0341] (Embodiment 6) This embodiment describes an example of mounting a secondary battery, which is one aspect of the present invention, into an electronic device. To clarify, electronic devices that implement secondary batteries include, for example, television equipment (television, or Television receivers (also called television receivers), computer monitors, digital cameras, digital cameras Video cameras, digital photo frames, mobile phones (also known as mobile phones or mobile phone devices) (u) Portable game consoles, personal information terminals, sound playback devices, and large game machines such as pachinko machines. Examples include notebook personal computers and tablet computers. These include terminals, e-books, and mobile phones.

[0342] Figure 17A shows an example of a mobile phone. The mobile phone 2100 is housed in a casing 2101. In addition to the built-in display unit 2102, there are operation buttons 2103, an external connection port 2104, and a speaker. It is equipped with a microphone 2106, etc. Furthermore, the mobile phone 2100 is a secondary power supply. It has a battery 2107. A secondary battery using a structure in which a fluorine-containing electrolyte is contained in the negative electrode. The inclusion of the 2107 allows for high capacity, and contributes to space saving through the miniaturization of the enclosure. It is possible to realize a configuration that can accommodate this.

[0343] The mobile phone 2100 is a mobile phone that can make calls, send emails, read and create documents, play music, and interact with other devices. - It can run various applications such as network communication and computer games. ru.

[0344] The operation button 2103 controls time setting, power on / off, wireless communication on, and more. Various functions such as operation, activation and deactivation of silent mode, and activation and deactivation of power saving mode. It can be made to hold. For example, the operating system built into the mobile phone 2100 The stem also allows you to freely configure the function of the operation button 2103.

[0345] Furthermore, the mobile phone 2100 is capable of performing standardized short-range wireless communication. Yes, for example, by communicating with a wireless headset, hands-free operation is possible. You can also make phone calls.

[0346] Furthermore, the mobile phone 2100 is equipped with an external connection port 2104, and can connect to other information terminals. Data can be exchanged directly via this. Also, via external connection port 2104... It can also be charged wirelessly. Note that the charging operation is performed wirelessly without going through the external connection port 2104. It may also be done by electricity.

[0347] The mobile phone 2100 preferably has a sensor. For example, a fingerprint sensor. S, pulse sensors, body temperature sensors and other human body sensors, touch sensors, pressure sensors, and acceleration sensors. It is preferable that sensors or the like are installed.

[0348] Figure 17B shows an unmanned aerial vehicle 2300 having multiple rotors 2302. The 300 is sometimes called a drone. The unmanned aerial vehicle 2300 is one aspect of the present invention. It has a secondary battery 2301, a camera 2303, and an antenna (not shown). Unmanned aerial vehicle The 2300 can be remotely controlled via an antenna. Fluorine-containing electrolyte is placed inside the negative electrode. Secondary batteries using the structure described above have high energy density and high safety, and can be used for long periods of time. It can be used safely for extended periods and is suitable as a secondary battery for use in the Unmanned Aerial Vehicle 2300. be.

[0349] Figure 17C shows an example of a robot. The robot 6400 shown in Figure 17C is secondary Battery 6409, light sensor 6401, microphone 6402, upper camera 6403, Peeker 6404, display unit 6405, lower camera 6406 and obstacle sensor 6407, It is equipped with a dynamic mechanism 6408, a computing device, and the like.

[0350] Microphone 6402 has the function of detecting the user's voice and ambient sounds, etc. Furthermore, speaker 6404 has the function of emitting sound. Robot 6400 is microf To communicate with the user using the phone 6402 and speaker 6404. This is possible.

[0351] The display unit 6405 has the function of displaying various information. The robot 6400 is used It is possible to display the information desired by the user on the display unit 6405. The display unit 6405 is a touch It may also be equipped with a control panel. Furthermore, the display unit 6405 is a removable information terminal. It's also fine to install it in a fixed position on the robot 6400 for charging and data transfer. This makes it possible.

[0352] The upper camera 6403 and the lower camera 6406 image the area around the robot 6400. It has the function of. In addition, the obstacle sensor 6407 uses the moving mechanism 6408 to move the robot 64 Robot 6 can detect the presence or absence of obstacles in the direction of travel as 00 moves forward. The 400 uses an upper camera 6403, a lower camera 6406, and an obstacle sensor 6407. This allows them to perceive their surroundings and move safely.

[0353] The robot 6400 has a secondary battery 6409 according to one aspect of the present invention and a semiconductor in its internal region. It comprises a body device or electronic components. It uses a structure in which a fluorine-containing electrolyte is contained in the negative electrode. The next battery has high energy density and high safety, allowing for safe use over long periods of time. It can be used and is suitable as a secondary battery 6409 to be mounted on the robot 6400.

[0354] Figure 17D shows an example of a cleaning robot. The cleaning robot 6300 has a housing 630 1 Display unit 6302 located on the top surface, multiple cameras 6303 located on the side, brush 6 It has components 304, an operation button 6305, a secondary battery 6306, various sensors, etc. Although not present, the 6300 cleaning robot is equipped with wheels, a suction nozzle, etc. The Bot 6300 is self-propelled, detects debris 6310, and removes debris from the suction port located on its underside. It can be used for suction.

[0355] For example, the cleaning robot 6300 analyzes images captured by the camera 6303 to identify walls, furniture, etc. Alternatively, it can determine the presence or absence of obstacles such as steps. Furthermore, image analysis can determine wiring... If an object that may become entangled in brush 6304 is detected, the rotation of brush 6304 will be stopped. The cleaning robot 6300 has a secondary battery according to one aspect of the present invention in its internal region. 6306 comprises a semiconductor device or electronic component. It has a fluorine-containing electrolyte in the negative electrode. Secondary batteries using this structure have high energy density and high safety, and can be used for long periods of time. It allows for safe use over long periods and is suitable as the rechargeable battery 6306 for the cleaning robot 6300. It is suitable.

[0356] This embodiment can be implemented in appropriate combination with other embodiments.

[0357] (Notes regarding the descriptions in this specification, etc.) Furthermore, in this specification, crystal planes and directions are indicated by Miller indices. In crystallography, numbers are represented with a superscript bar, but in this specification, due to limitations on patent application notation, the numbers are represented as follows: Sometimes, instead of placing a bar above a letter, a minus sign (-) is placed before the number to represent it. Furthermore, the individual orientations indicating directions within a crystal are [ ], and the collective orientation showing all equivalent directions is < > represents individual crystal planes ( ), and sets of planes with equivalent symmetry are {}. They express each other.

[0358] In this specification, segregation refers to the process of a solid composed of multiple elements (e.g., A, B, C). This refers to the phenomenon in which a certain element (for example, B) is distributed non-uniformly in space.

[0359] In this specification, the surface layer of particles such as active material refers, for example, to within 50 nm from the surface. Preferably, the region is within 35 nm, and even more preferably, within 20 nm. Surfaces formed by cracks and fissures can also be considered surfaces. Furthermore, areas deeper than the surface layer are considered surfaces. It's called the interior.

[0360] In this specification, etc., layered rock salt-type crystals of composite oxides containing lithium and transition metals The structure has a rock salt-type ionic arrangement in which cations and anions are arranged alternately, and transition metals Because lithium is arranged in a regular pattern to form a two-dimensional plane, two-dimensional diffusion of lithium is possible. This refers to a crystal structure. It may also have defects such as vacancies in cations or anions. Strictly speaking, a layered rock salt crystal structure is a structure in which the lattice of rock salt crystals is distorted. There is.

[0361] Furthermore, in this specification and elsewhere, a rock salt-type crystal structure is defined as a structure in which cations and anions are arranged alternately. This refers to a structure that is characterized by the presence of a cation or anion. A deficiency in either a cation or anion is also acceptable.

[0362] Furthermore, in this specification, etc., the pseudo-spinel type of composite oxide containing lithium and a transition metal The crystal structure of cobalt is space group R-3m, and although it is not a spinel-type crystal structure, it is cobalt Magnesium and other ions occupy the 6-coordinate position of oxygen, and the arrangement of cations is similar to that of a spinel. This refers to a crystal structure that possesses symmetry.

[0363] The approximate agreement of the crystal orientation in the two regions can be seen in TEM (transmission electron microscope) images and STE (spherical spectroscopy) images. M (Scanning Transmission Electron Microscope) image, HAADF-STEM (High-angle scattering annular dark-field scanning transmission electron microscope) image. The determination should be made based on images from a microscope, ABF-STEM (annular bright-field scanning transmission electron microscope), etc. This can be done. X-ray diffraction (XRD), electron diffraction, neutron diffraction, etc. can also be used as criteria for judgment. Yes, it is possible. In TEM images, the arrangement of cations and anions can be observed as a repetition of bright and dark lines. It can be inferred. When the orientation of the cubic close-packed structure is aligned in layered rock salt crystals and rock salt crystals, the crystal In between, the angle between the repetition of bright and dark lines is 5 degrees or less, more preferably 2.5 degrees or less. The condition can be observed. Furthermore, light elements such as oxygen and fluorine are clearly visible in TEM images, etc. In some cases, it may not be possible to discern this, but in such cases, the alignment of the metal elements can be determined by their arrangement. ru.

[0364] Furthermore, in this specification, the theoretical capacity of the positive electrode active material refers to the insertion and removal capacity of the positive electrode active material. This refers to the amount of electricity that would be generated if all the lithium were to be desorbed. For example, the theoretical capacity of LiCoO2 is 27 The theoretical capacity of LiNiO2 is 274mAh / g, and the theoretical capacity of LiMn2O4 is 4mAh / g. The capacity is 148mAh / g.

[0365] Furthermore, in this specification, etc., the charging depth when all insertable and removable lithium is inserted. The degree is 0, and the charge depth when all the insertable and detachable lithium in the positive electrode active material has been detached is 1. Let's assume that's the case.

[0366] Furthermore, in this specification, charging means moving lithium ions from the positive electrode to the negative electrode within the battery. This refers to the movement of electrons, specifically from the positive electrode to the negative electrode in an external circuit. Therefore, the process of releasing lithium ions is called charging. Also, the charging depth is 0.7 or higher. Positive electrode active materials with a voltage of 0.9 or less are sometimes referred to as positive electrode active materials charged with high voltage.

[0367] Similarly, discharge is the movement of lithium ions from the negative electrode to the positive electrode within a battery, and externally... This refers to the movement of electrons from the negative electrode to the positive electrode in a circuit. The positive electrode active material is lithium. The insertion of ions is called discharge. Also, the positive electrode active material has a charge depth of 0.06 or less, The positive electrode active material, which has been discharged to more than 90% of its charge capacity from a state of being charged at high voltage, This refers to the positive electrode active material that has been discharged for a certain amount of time.

[0368] Furthermore, in this specification, a non-equilibrium phase change refers to a phenomenon that causes a nonlinear change in a physical quantity. Let's assume that this is the case. For example, it can be obtained by differentiating capacitance (Q) with respect to voltage (V) (dQ / dV). Around the peaks in the dQ / dV curve, non-equilibrium phase transitions occur, and the crystal structure changes significantly. It is thought that they understand.

[0369] A secondary battery has, for example, a positive electrode and a negative electrode. The positive electrode active material is a material that makes up the positive electrode. Yes. The positive electrode active material is, for example, a substance that performs a reaction that contributes to the charge and discharge capacity. The active material may include, in part, substances that do not contribute to the charge / discharge capacity. One of the materials is the negative electrode active material. The negative electrode active material performs reactions that contribute to the charge and discharge capacity, for example. It is a substance that does not contribute to the charge / discharge capacity. But that's fine.

[0370] In this specification, the positive electrode active material according to one aspect of the present invention is a positive electrode material or for secondary batteries. It may be expressed as positive electrode material, etc. Also, in this specification, etc., positive electrode activity of one aspect of the present invention The substance preferably contains a compound. Furthermore, in this specification, etc., the correctness of one aspect of the present invention The highly active material preferably has a composition. Furthermore, in this specification, etc., one aspect of the present invention The positive electrode active material preferably has a composite structure.

[0371] In this specification, the negative electrode active material according to one aspect of the present invention is a negative electrode material or for secondary batteries. It may be expressed as negative electrode material, etc. Also, in this specification, etc., negative electrode activity of one embodiment of the present invention The substance preferably contains a compound. Furthermore, in this specification, etc., the negative of one aspect of the present invention The highly active material preferably has a composition. Furthermore, in this specification, etc., one aspect of the present invention The negative electrode active material preferably has a composite structure.

[0372] The discharge rate is the relative ratio of the current during discharge to the battery capacity, and is expressed in units of C. In a battery with a rated capacity of X (Ah), the current equivalent to 1C is X (A). 2X( If the discharge is performed with the current A), it is said that the discharge was performed at 2C, and if the discharge is performed with a current of X / 5(A) In that case, it was discharged at 0.2C. The charging rate was also similar, 2X(A). If it is charged with a current of X / 5(A), it is said to have been charged at 2C, and if it is charged with a current of X / 5(A) In that case, it was charged at 0.2C.

[0373] Constant current charging refers to a method of charging where the charging rate is kept constant. For example, this refers to a method where, once the charging voltage reaches its upper limit, the voltage is kept constant and charging continues. Discharge refers to a method of performing a discharge while maintaining a constant discharge rate. [Examples]

[0374] In this embodiment, a negative electrode according to one aspect of the present invention was fabricated, and the fabricated negative electrode was evaluated.

[0375] <Fabrication of the negative electrode> The negative electrode was fabricated following the flow shown in Figure 4. As silicon-containing particles, ALDRI We used nanosilicon particles made of CH. For the graphite-containing particles, we used those manufactured by Nippon Graphite Industries Co., Ltd. Spheroidized graphite particles CGB-15 were used. Graphene oxide was used as the graphene compound. A polyimide precursor manufactured by Toray Industries, Inc. was used as the polyimide.

[0376] Electrodes GS1, GS2, GS3, and GS4 were fabricated as negative electrodes. Electrodes GS1 through GS4 were prepared using the same method, except for the electrode compounding ratios listed in Table 1. The electrode composition ratios shown in Table 1 are used in the fabrication of electrodes GS1 to GS4, as shown in Figure 4. This is the weight ratio of the materials prepared in steps S61, S72, S80, and S87. Details are explained below.

[0377] [Table 1]

[0378] Nanosilicon particles and a solvent were prepared and mixed (steps S61 and S62 in Figure 4). S63). NMP was used as the solvent. Mixing was done with a rotational mixer (Awatori Rentaro, TH). Mixing was performed at 2000 rpm for 3 minutes using INKY Co., Ltd., and the mixture was recovered to obtain mixture E-1 (Figure). Step 4 (S64, S65).

[0379] Next, spheroidized graphite particles were prepared and mixed with mixture E-1 (steps S72, S in Figure 4). 73) Mixing is performed using a rotary-orbit mixer at 2000 rpm for 3 minutes, then the mixture is collected and the mixture is prepared. E-2 was obtained (steps S74 and S75 in Figure 4).

[0380] Next, the mixture E-2 and the graphene compound are repeatedly mixed while adding solvent. As the graphene compound, graphene oxide was prepared, and the mixing was done using a rotational mixer. The mixture was mixed at 2000 rpm for 3 minutes and then collected (steps S80, S81, and S82 in Figure 4). Next Next, the recovered mixture is kneaded into a solid mass, NMP is added as needed, and then a rotational-orbital mixer is used. Mixed at 2000 rpm for 3 minutes and then collected (steps S83, S84, and S8 in Figure 4). 5) Steps S83 to S85 were repeated five times to obtain mixture E-3. (Step S86 in Figure 4).

[0381] Next, mixture E-3 was mixed with the polyimide precursor (step S88 in Figure 4). Mixing was performed using a rotation-orbit mixer at 2000 rpm for 3 minutes. After that, NMP was prepared. Prepare the mixture, add it to adjust the viscosity (step S89 in Figure 4), and then mix further. (Mixed twice at 2000 rpm for 3 minutes in a rotary-orbit mixer), collected and used as a slurry, then mixed. E-4 was obtained (steps S90, S91, S92 in Figure 4).

[0382] Next, the current collector was prepared and coated with mixture E-4 (steps S93 and S94 in Figure 4). ). Prepare copper foil with an undercoat as the current collector, and apply mixture E-3 to the gap thickness. Using a 100 μm doctor blade, mixture E-4 was coated onto the copper foil. The copper foil is 18 μm thick, and the current collector has a carbon-containing coating layer as an undercoat. This was used. AB was used as the raw material for the carbon-containing coating layer.

[0383] Next, the copper foil coated with mixture E-4 was subjected to a first heating at 50°C for 1 hour (Figure 4). Step S95). Then, a second heating is performed under reduced pressure at 400°C for 5 hours (Figure 4). Step S96) yielded an electrode. Heating reduced the graphene oxide, decreasing the amount of oxygen. do.

[0384] <sem> SEM observation was performed on the surface of the fabricated electrodes. The SEM observation was performed at the timing after the first heating. The experiment was conducted using a Hitachi High-Technologies SU8030 SEM. The acceleration voltage was 5 It was set to kV.

[0385] Figures 18A and 18B show observed images of the surface of electrode GS1, respectively. Figures 19B and 20A show the surface of electrode GS2, respectively. These are observation images of the surface of electrode GS3. Figures 21A and 21B show the surface of electrode G3, respectively. This is an observation image of the surface of S4. In the SEM image, the nanosilicon particles appear relatively bright. It shows a thrombolytic effect.

[0386] Figure 18B shows graphite particles with a particle size of approximately 10 μm to 20 μm present in electrode GS1. This is a magnified image of the surface. Nanosilicon particles, approximately 50 nm to 250 nm in size, are graphite particles. It exists on the surface and consists of regions covered with graphene oxide and regions not covered with graphene oxide. A region was observed.

[0387] Figure 19B shows graphite particles with a particle size of approximately 10 μm to 20 μm present in electrode GS2. This is a magnified view of the surface. Nanosilicon particles, approximately 50 nm to 250 nm in size, are graphite particles. It exists on the surface and consists of regions covered with graphene oxide and regions not covered with graphene oxide. A region was observed. In GS2, there was a larger area covered by graphene oxide than in GS1. There is a tendency for this to happen.

[0388] Figure 20B shows graphite particles with a particle size of approximately 10 μm to 20 μm present in electrode GS3. This is a magnified view of the surface. Nanosilicon particles, approximately 50 nm to 250 nm in size, are graphite particles. It exists on the surface and consists of regions covered with graphene oxide and regions not covered with graphene oxide. A region was observed. In GS3, the region was more covered with graphene oxide than in GS2. There is a tendency for this to be the case.

[0389] Figure 21B shows graphite particles with a particle size of approximately 10 μm to 20 μm present in electrode GS4. This is a magnified view of the surface. Nanosilicon particles, approximately 50 nm to 250 nm in size, are graphite particles. It exists on the surface and consists of regions covered with graphene oxide and regions not covered with graphene oxide. A region was observed. In GS4, the region was covered by graphene oxide even more than in GS3. There is a tendency for the region to be large, and most of the nanosilicon is covered by multiple layers of graphene oxide.

[0390] <Coin cell fabrication> Next, using the fabricated electrodes GS1 to GS4, a CR2032 type (20mm diameter) is used. A coin cell with a height of 3.2 mm was fabricated.

[0391] Lithium metal was used as the counter electrode. Lithium hexafluoride phosphate (LiPF) was used as the electrolyte. 6) However, ethylene carbonate (EC) and diethyl carbonate (DEC) are EC:DE A mixture of C=3:7 (volume ratio) versus a mixture with a concentration of 1 mol / L. I used it.

[0392] A 25 μm thick polypropylene separator was used for the separator.

[0393] The positive electrode and negative electrode cans were made of stainless steel (SUS).

[0394] <Charge / discharge characteristics> The charge and discharge characteristics were evaluated using the fabricated coin cell. During discharge, lithium is absorbed into the electrodes, and during charging, lithium is released from the electrodes. .

[0395] Discharge conditions (lithium storage) are constant current discharge (0.1C, lower limit voltage 0.01V) followed by constant current discharge. Voltage discharge (lower limit current density 0.01C) and charging conditions (lithium discharge) are constant current charging (0 The current was set to 0.1C (maximum voltage 1V). Discharging and charging were performed at 25°C. The change in capacity with respect to the number of cycles is shown in Figures 22A and 22B. Table 2 shows the maximum charging capacity and the charging capacity retention rate after 40 cycles.

[0396] [Table 2]

[0397] Regarding the electrode composition ratio and characteristics of electrodes GS1 to GS4, Figure 23 plots the GO / silicon ratio and the discharge capacity retention rate after 40 cycles. The following is shown. The electrode mixing ratio of graphene oxide and silicon in electrode fabrication is when the amount of silicon is 1 In this case, the ratio of the amount of graphene oxide is preferably 0.05 or higher, and preferably 0.10 or higher. It is found that a ratio of 0.30 or higher is preferable, and even more preferable. The electrode formulations shown in Table 2 are also relevant. The ratio is as follows in the fabrication of electrodes GS1 to GS4, in steps S61 and S72 of Figure 4. This is the weight ratio of the materials prepared in S80. [Explanation of symbols]

[0398] 300: Secondary battery, 301: Positive electrode can, 302: Negative electrode can, 303: Gasket, 304: Positive electrode, 305: positive electrode current collector, 306: positive electrode active material layer, 307: negative electrode, 308: negative electrode current collector, 309: Negative electrode active material layer, 310: Separator, 312: Washer, 313: Ring-shaped insulation Edge body, 322: Spacer, 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 : Separator, 508: Electrolyte, 509: Outer casing, 510: Positive lead electrode, 511: Negative Electrode lead, 570: electrode, 570a: negative electrode, 570b: positive electrode, 571: current collector, 57 1a: negative electrode current collector, 571b: positive electrode current collector, 572: active material layer, 572a: negative electrode active material layer 572b: positive electrode active material layer, 576: electrolyte, 581: first particle, 582: second particle , 583: Material having a sheet-like shape, 584: Electrolyte, 601: Positive electrode cap, 60 2: Battery can, 603: Positive terminal, 604: Positive electrode, 605: Separator, 606: Negative electrode, 6 07: Negative terminal, 608: Insulating plate, 609: Insulating plate, 611: PTC element, 613: Safety Valve mechanism, 614: Conductive plate, 615: Energy storage system, 616: Secondary battery, 620: Control circuit , 621: wiring, 622: wiring, 623: wiring, 624: conductor, 625: insulator, 62 6: Wiring, 627: Wiring, 628: Conductive plate, 700: Power storage device, 701: Commercial power supply, 7 03: Distribution board, 705: Energy storage controller, 706: Display unit, 707: General load, 708 : Energy storage load, 709: Router, 710: Service drop connection section, 711: Measurement section, 712: Prediction Department, 713: Planning Department, 790: Control Device, 791: Energy Storage Device, 796: Underfloor Space Department, 79 9: Building, 911a: Terminal, 911b: Terminal, 913: Secondary battery, 930: Enclosure, 930 a: Housing, 930b: Housing, 931: Negative electrode, 931a: Negative electrode active material layer, 932: Positive electrode, 9 32a: Positive electrode active material layer, 933: Separator, 950: Winding body, 950a: Winding body, 95 1: Terminal, 952: Terminal, 1300: Rectangular rechargeable battery, 1301a: Battery, 1301b :Battery, 1302:Battery controller, 1303:Motor controller, 13 04: Motor, 1305: Gear, 1306: DC-DC circuit, 1307: Electric power steering, 1 308: Heater, 1309: Defogger, 1310: DC-DC circuit, 1311: Battery Ri, 1312: Inverter, 1313: Audio, 1314: Power window, 13 15: Lamps, 1316: Tires, 1317: Rear motor, 1320: Control circuit unit, 1 321: Control circuit section, 1322: Control circuit section, 1324: Switch section, 1325: External terminals , 1326: External terminal, 1413: Fixing part, 1414: Fixing part, 1415: Battery pack, 1421: Wiring, 1422: Wiring, 2001: Automobile, 2002: Transport vehicle, 2003: Export Vehicle transport, 2004: Aircraft, 2100: Mobile phone, 2101: Housing, 2102: Display unit , 2103: Operation buttons, 2104: External connection port, 2105: Speaker, 2106: Microphone, 2107: rechargeable battery, 2200: battery pack, 2201: battery pack, 2202 : Battery pack, 2203: Battery pack, 2300: Unmanned aerial vehicle, 2301: Rechargeable battery, 2 302: Rotor, 2303: Camera, 2603: Vehicle, 2604: Charging device, 2610 : Solar panel, 2611: Wiring, 2612: Energy storage device, 6300: Cleaning robot, 6 301: Enclosure, 6302: Display unit, 6303: Camera, 6304: Brush, 6305: Control Activation button, 6306: rechargeable battery, 6310: trash, 6400: robot, 6401: illuminance Sensor, 6402: Microphone, 6403: Top camera, 6404: Speaker, 64 05: Display unit, 6406: Lower camera, 6407: Obstacle sensor, 6408: Moving mechanism, 6409: Secondary battery< / sem>

Claims

1. It comprises a first active material, a second active material, a graphene compound, and a binder. The first active material has a particle size of 1 μm or less and contains silicon. The second active material has a larger particle size than the first active material and contains graphite. The first active material is located on the surface of the second active material, The graphene compound is in contact with the first active material and in contact with the second active material. The binder is an electrode having polyimide.

2. In claim 1, The graphene compound has pores, The aforementioned hole is an electrode composed of a multi-membered ring with 18 or more members.

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