Secondary batteries

Abstract

To provide a robust secondary battery even when an external force is added because when a film is used for an exterior body of the secondary battery, the strength of the film is weaker than a metal can, a collector arranged in an area encircled by the exterior body, an active material layer provided on a collector surface, or the like can be damaged when the external force is added.SOLUTION: An opening part is provided for a central part of a secondary battery, and a terminal is formed in the opening. An outside periphery of the secondary battery is fixed by thermal compression. Moreover, the central part of the secondary battery is fixed by thermal compression, and even when the outside peripheral part of the secondary battery is bent, an amount of bending is limited.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In this specification, the term "electronic device" refers to any device that has a secondary battery. Electro-optical devices having a secondary battery, and information terminal devices having a secondary battery are all electronic devices. [Background technology]

[0003] Electronic devices that are carried by users or worn by users are being actively developed. For example, Patent Document 1 describes a thin portable book.

[0004] Electronic devices carried by users or worn by users operate using secondary batteries as their power source. It is desirable for users to use portable electronic devices for long periods of time, and for this reason, large-capacity If a large-capacity secondary battery is built into an electronic device, Therefore, it is necessary to develop a small or thin type that can be built into portable electronic devices. Development of large-capacity secondary batteries is underway.

[0005] Secondary batteries are constructed so that a metal can is used as an exterior body and an electrolyte is stored in the metal can. It has become a success. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Unexamined Patent Publication No. 15796 / 1983 Summary of the Invention [Problem to be solved by the invention]

[0007] When a metal can is used as the exterior body, there is a problem that the weight of the secondary battery itself increases. To realize a thin secondary battery, it is difficult to manufacture a thin metal can by molding. It is also difficult to fabricate a secondary battery using a thin metal can.

[0008] The exterior is made of a laminate of metal foil (aluminum, stainless steel, etc.) and resin (thermal adhesive resin). When a film containing cellulose ether (also called a laminate film) is used, it is possible to reduce the energy consumption compared to secondary batteries that use metal cans. It is also lightweight, making it possible to fabricate a thin secondary battery.

[0009] To make the display device worn on the human body more comfortable for the user, it is necessary to make it lightweight and There is a demand for smaller and lighter electronic devices, including the drive unit and power supply for the display device. is required.

[0010] To provide an electronic device with a novel structure, specifically, one that can be made into various external shapes. To provide an electronic device with a novel structure.

[0011] Another object of one embodiment of the present invention is to provide a novel power storage device, a novel secondary battery, or the like. The description of these issues does not preclude the existence of other issues. An embodiment of the invention does not necessarily have to solve all of these problems. Other problems will be obvious from the description, drawings, claims, etc. It is possible to extract other issues from the specifications, drawings, claims, etc. [Means for solving the problem]

[0012] When a film is used as the exterior of a secondary battery, the strength of the film is weaker than that of a metal can, and the external When a force is applied from the inside of the exterior body, the current collector disposed inside the exterior body or the The current collector is connected to the lead electrode. The battery has a protruding portion (also called an electrode tab portion) that prevents the secondary battery from bending when an external force is applied. When the current collector is turned on, damage such as cracks occurs around the protruding part (electrode tab part), This will lead to damage to the next battery. Note that no active material layer is provided on the electrode tab portion.

[0013] Thin secondary batteries that use laminated film for the exterior have electrode shapes that are prone to cracking, i.e. That is, it has a protruding portion (electrode tab portion) that protrudes partially to allow the lead electrode to be drawn out. .

[0014] When bending a thin secondary battery that uses a laminate film as its exterior, the external force caused by the bending The secondary battery with a new configuration is highly resistant to the effects of the above and has an electrode tab located in the center of the secondary battery. The secondary battery has an external appearance that is point symmetrical with respect to the electrode tab portion.

[0015] The configuration disclosed in this specification is a secondary battery in which an electrolyte solution is sealed in an exterior body, and a first current collector a second current collector on the first current collector; an outer casing having an opening; and a first current collector in the opening. a part of the second current collector protrudes into the opening, and the outer casing is a film. This secondary battery is characterized by:

[0016] In the above configuration, the part of the first current collector that protrudes into the opening is a terminal of the positive electrode, One of the features of the present invention is that the part of the second current collector that protrudes outward serves as a negative electrode terminal.

[0017] In the above structure, a separator is provided between the first current collector and the second current collector. The first current collector may have a plurality of openings. The second current collector may have a plurality of openings. By providing a plurality of openings in the first current collector or the second current collector, a part of the current collector can be This makes it easier to bend, and the position at which the current collector bends when bent can be controlled.

[0018] The outer periphery of the secondary battery is fixed by thermocompression. The secondary battery is fixed by adhesive, and the amount of bending of the outer peripheral edge of the secondary battery is limited. The secondary battery contains multiple current collectors inside, and is surrounded by an exterior body. In the above configuration, the opening of the secondary battery is a through hole. The opening of the exterior body is a hollow structure, and when sealed, part of the exterior body becomes a current collector. The opening located in the center of the secondary battery when viewed from above is fixed. When the secondary battery is bent, the area where the exterior body and the current collector are not fixed, especially the outer periphery, The difference between the deformation amount of the exterior body and the deformation amount of the current collector can be made smaller than before. When a plurality of current collectors are used, the difference in deformation amount between the top current collector and the bottom current collector can be reduced. The center of the secondary battery is fixed by thermocompression, so that the secondary battery is resistant to deformation. Conventionally, a positive (or negative) terminal protruding from one side of a rectangular secondary battery The current collector is fixed at the part where one side of the current collector overlaps with the current collector. In the area away from the side, the difference between the deformation amount of the outer casing and the deformation amount of the current collector is large, The difference in deformation between the top and bottom current collectors also becomes larger internally. When the difference in deformation between the current collector and the bottom current collector becomes large, the first and second current collectors in a pair become distorted. The area that does not overlap with the current collector 2 does not function as a battery, leading to a reduction in capacity.

[0019] In addition, since the connection is made to the center of the secondary battery, the element and By arranging the circuit, the length of the wiring (lead wires, etc.) can be shortened, reducing wiring resistance. It is also possible to place elements or circuits (such as a regulator) on the center of the secondary battery. It is especially difficult to place the device in a thin housing since there is little storage space inside the housing. This is advantageous when mounting a secondary battery. The regulator It generates and supplies the power or signals required for each functional circuit. The regulator can also prevent the secondary battery from being overcharged.

[0020] In addition, in the case of thin secondary batteries, the external size of the secondary battery is increased around the electrode tab portion. This also makes it possible to increase the area. [Effects of the Invention]

[0021] A secondary battery having a new configuration can be realized. If the housing of an electronic device equipped with a battery is deformed, the secondary battery will deform along with the housing, but the secondary battery will not Reduce the amount of deformation caused by battery deformation.

[0022] Furthermore, electronic devices with novel structures can be realized that include secondary batteries with the novel configuration.

[0023] Do not place electronic devices equipped with secondary batteries near parts of the human body (e.g., elbows, shoulders, knees, head, or other parts that include spherical surfaces). ) can be used in manufacturing, police, fire departments, medical care, elderly care, distribution, product sales, etc. This is useful for work styles that require free use of hands.

[0024] The description of these effects does not preclude the existence of other effects. The embodiment does not necessarily have to have all of these effects. , the specification, drawings, claims, etc., and It is possible to extract other effects from the claims and other descriptions. [Brief explanation of the drawings]

[0025] [Figure 1] 1A and 1B are a top view and a cross-sectional view illustrating one embodiment of the present invention. [Figure 2] FIG. 1 is a top view illustrating one embodiment of the present invention. [Figure 3] FIG. 1 is a cross-sectional view illustrating one embodiment of the present invention. [Figure 4] 1A and 1B are a perspective view and a cross-sectional view illustrating one embodiment of the present invention. [Figure 5] 1 illustrates an electronic device according to one embodiment of the present invention. [Figure 6] 1 illustrates an electronic device according to one embodiment of the present invention. [Figure 7] 1 illustrates an electronic device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the following description, and various modifications in form and details are possible by those skilled in the art. Furthermore, the present invention should not be construed as being limited to the description of the following embodiments. It is not something that can be done.

[0027] In each drawing described in this specification, the size of each component, the thickness of a layer, or the area is The figures may be exaggerated or abbreviated for clarity. This is not limited to rules.

[0028] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components. It does not indicate any order or ranking such as the order of processes or stacking. In addition, even if a term is not accompanied by an ordinal number in this specification, etc., it is possible to avoid confusion of the constituent elements. To avoid this, ordinal numbers may be used in the claims.

[0029] (Embodiment 1) FIG. 1A shows an example of a schematic top view of a power storage unit.

[0030] The power storage unit 100 of one embodiment of the present invention includes a positive electrode 101, a separator 103, and an outer casing 107. The power storage device has at least a negative electrode 102 and an electrolyte solution 120. In this embodiment, the exterior body 107 is formed using a film.

[0031] In this embodiment, a laminated film having two circular openings is folded to form a film having two openings. The edges of the opening are heat-pressed together so that they overlap. The outer edges (3 sides) are also heat-pressed. are.

[0032] Also, a first laminated film having one circular opening and a second laminated film having one circular opening are The two openings are overlapped with a second laminated film, and the periphery and outer The four sides may be sealed by thermocompression.

[0033] An example of a top view of the positive electrode 101 is shown in FIG. 1(B). The positive electrode 101 is formed by openings in the laminated film. The electrode tabs are provided with overlapping openings, and the electrode tabs are protruding from the openings. The positive electrode 101 is a terminal for connecting to a wire. The term "positive electrode" includes those in which a positive electrode active material layer is provided on one or both sides. The electrode active material layer is not formed on the region of the current collector that will become the terminal, that is, the electrode tab portion.

[0034] 1D shows an example of a top view of the negative electrode 102. The negative electrode 102 also has an opening in the laminated film. The negative electrode 102 has an opening that overlaps with the electrode tab portion, and the electrode tab portion protrudes. The term "negative electrode" also refers to a body (such as copper) with a negative electrode active material layer on one or both sides. The negative electrode active material layer is formed in the area of ​​the current collector that becomes the terminal, that is, the electrode tab portion. It won't work.

[0035] In this embodiment, the power storage unit is configured such that, for example, the thickness of the separator 103 is about 15 μm. the positive electrode 101 current collector is about 10 μm or more and about 40 μm or less, and the positive electrode active material layer the negative electrode active material layer is about 50 μm or more and about 100 μm or less, and the negative electrode active material layer is about 50 μm or more and about 100 μm or less, The current collector of the negative electrode 102 has a thickness of about 5 μm or more and about 40 μm or less.

[0036] An example of a top view of a separator 103 disposed between the positive electrode 101 and the negative electrode 102 is shown in FIG. C). The separator also has an opening that overlaps with the opening of the laminated film. In the example shown in FIG. 1(C), the separator 103 is a sheet-like separator, but a bag-like separator may also be used. Alternatively, one separator may be folded and the positive electrode (or The cathode (positive electrode) may be located inside the exterior body 107.

[0037] FIG. 1(E) is a schematic cross-sectional view taken along the chain line AB in FIG. 1(A).

[0038] FIG. 1(E) shows a configuration in which the electrode tab portion protrudes from the exterior body 107. In this example, the positive electrodes of the two electrodes are stacked and ultrasonically bonded to form a laminate that serves as one terminal. With this configuration, the terminal electrodes can be formed without using lead electrodes.

[0039] In this embodiment, for the sake of simplicity, the electrolyte solution 120 is shown in FIG. 1, an example in which three pairs of positive electrodes 101 and negative electrodes 102 are housed in an exterior body 107 is shown. In order to increase the capacity, four or more pairs of positive electrodes 101 and negative electrodes 102 are combined in an outer casing 10. 7. In order to make the storage body thinner, two or one set of positive electrode 101 and negative electrode The combination of 102 may be housed in an exterior body 107.

[0040] In addition, to prevent short circuits between the positive and negative electrodes in the center, an insulating layer is placed between the positive and negative electrode tabs. It is preferable to provide a body.

[0041] An example of how to fabricate the electricity storage unit 100 will be described below.

[0042] First, three positive electrodes (including current collectors with the shape shown in Figure 1(B)) and five separators were (separator having the shape shown in Figure 1(C)) and three negative electrodes (having the shape shown in Figure 1(D) The positive electrode 101 has multiple slits in addition to the central opening. The positive electrode has a number of openings, which makes it less likely to wrinkle when the storage battery is bent. The positive electrode 101 has a positive electrode active material layer on one or both sides. In addition to the central opening, there are multiple openings as slits, so that when the storage battery is bent, the load is The negative electrode 102 has a structure that makes it difficult for wrinkles to occur. It has a material layer.

[0043] The current collectors used for the positive electrode 101 and the negative electrode 102 may be stainless steel, gold, platinum, zinc, iron, nickel, or the like. Conductive materials such as nickel, copper, aluminum, titanium, tantalum, and alloys thereof It is possible to use a material that has high conductivity and does not alloy with carrier ions such as lithium. Elements that improve heat resistance, such as silicon, titanium, neodymium, scandium, and molybdenum It is also possible to use an aluminum alloy containing silicon. It may be formed of a metal element that forms a silicide by reacting with silicon. The group elements are zirconium, titanium, hafnium, vanadium, niobium, tantalum, There are chromium, molybdenum, tungsten, cobalt, nickel, etc. The current collector is 5 It is recommended to use one with a thickness of 40 μm or more.

[0044] A positive electrode active material layer is formed on one or both surfaces of the current collector used for the positive electrode 101 .

[0045] The positive electrode active material used in the positive electrode active material layer of the electricity storage unit 100 may have an olivine type crystal structure, a layered structure, or the like. There are composite oxides with rock salt crystal structures or spinel crystal structures. As a substance, for example, LiFeO2, LiCoO2, LiNiO2, LiMn2O4, V2O 5, compounds such as Cr2O5, MnO2, etc. are used.

[0046] Alternatively, a composite material (general formula LiMPO4, where M is one or more of Fe(II), Mn(II), Co(I I), Ni(II))) can be used. Representative examples of the general formula LiMPO4 include LiFePO4, LiNiPO4, LiCoPO4, LiMnPO4, LiFe a Ni b PO4, LiFe a Co b PO4, LiFe a Mn b PO4, LiNi a Co b PO4, LiNi a Mn b PO4 (a + b ≤ 1, 0 < a < 1, 0 < b < 1), LiF e c Ni d Co e PO4, LiFe c Ni d Mn e PO4, LiNi c Co<s d Mn e PO 4 (c + d + e ≤ 1, 0 < c < 1, 0 < d < 1, 0 < e < 1), LiFe f Ni g C o h Mn i PO4 (f + g + h + i ≤ 1, 0 < f < 1, 0 < g < 1, 0 < h < 1, 0 < i < 1), etc. Lithium compounds can be used as materials. <s

[0047] Alternatively, a composite material such as the general formula Li (2-j) MSiO4 (M is one or more of Fe(II), Mn(II), Co( II), Ni(II), 0 ≤ j ≤ 2) can be used. Representative examples of the general formula Li (2-j) MSiO4 include Li (2-j) FeSiO4, Li (2 -j) NiSiO4, Li (2-j) Please note that there might be some formatting issues in the original text which might affect the readability of the translation. Also, some tags seem to be repeated or have incorrect sequences which might need further clarification in the source document for a more accurate translation.CoSiO4, Li (2-j) MnSiO4, Li (2-j) Fe k Ni l SiO4, Li (2-j) Fe k Co l SiO4, Li (2-j ) Fe k Mn l SiO4, Li (2-j) Ni k Co l SiO4, Li (2-j) Ni k Mn l SiO4 (k + l is 1 or less, 0 < k < 1, 0 < l < 1), Li<​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​3, Fe2(SO4)3, Li3Fe2(PO4)3, etc. Also, as a positive electrode active material , Li2MPO4F, Li2MP2O7, Li5MO4 (M=Fe, Mn) compounds, perovskite-type fluorides such as NaFeF3 and FeF3, TiS2, Mo Metal chalcogenides (sulfides, selenides, tellurides) such as S2, and reversed metals such as LiMVO4 Oxides with spinel-type crystal structure, vanadium oxides (V2O5, V6O 13 , L Materials such as iV3O8, manganese oxide, and organic sulfur can be used.

[0049] In addition, the carrier ions are alkali metal ions other than lithium ions, alkaline earth metal ions, etc. In the case of ions, instead of lithium, an alkali metal (e.g., sodium) is used as the positive electrode active material. alkaline earth metals (e.g., calcium, strontium, barium, etc.), Alternatively, ferrite, such as beryllium, or magnesium, may be used.

[0050] A negative electrode active material layer is formed on one or both surfaces of the current collector used for the negative electrode 102 .

[0051] The negative electrode active material used in the negative electrode active material layer of the electricity storage unit 100 is a lithium-ion battery prepared by dissolution and deposition, or Materials that can insert and extract lithium ions can be used, such as lithium metal and carbon-based materials. Materials, alloy materials, etc. can be used.

[0052] Lithium metal has a low oxidation-reduction potential (-3.045 V vs. the standard hydrogen electrode) and is lightweight and and high specific capacity per volume (3860mAh / g and 2062mAh / cm, respectively) 3 ) and is therefore preferable.

[0053] Carbon materials include graphite, easily graphitizable carbon (soft carbon), and non-graphitizable carbon (hard carbon). Examples include carbon nanotubes, graphene, and carbon black.

[0054] Graphite includes mesocarbon microbeads (MCMB), coke-based artificial graphite, and pitch. These include artificial graphite such as spheroidized artificial graphite, and natural graphite such as spheroidized natural graphite.

[0055] When lithium ions are inserted into graphite (when lithium-graphite intercalation compounds are formed), It exhibits a potential as low as that of lithium metal (0.1 to 0.3 V vs. Li / Li + ).child This allows lithium-ion secondary batteries to exhibit high operating voltages. , relatively high capacity per unit volume, small volume expansion, inexpensive, and comparable to lithium metal This is preferable because it has advantages such as higher safety compared to the conventional method.

[0056] As a negative electrode active material, it is possible to carry out charge-discharge reactions by alloying and dealloying reactions with lithium. A suitable alloy material or oxide can also be used. In some cases, the alloy material may be, for example, Al, Si, Ge, Sn, Pb, Sb, Bi, There are materials containing at least one of Ag, Au, Zn, Cd, In, Ga, etc. Such elements have a large capacity compared to carbon, and silicon in particular has a theoretical capacity of 4200mAh / g. Therefore, it is preferable to use silicon as the negative electrode active material. Examples of alloy materials using elements include Mg2Si, Mg2Ge, Mg2Sn, and SnS. 2, V2Sn3, FeSn2, CoSn2, Ni3Sn2, Cu6Sn5, Ag3Sn, Ag3Sb, Ni2MnSb, CeSb3, LaSn3, La3Co2Sn7, CoSb 3. InSb, SbSn, etc.

[0057] In addition, the negative electrode active material is SiO, SnO, SnO2, titanium dioxide (TiO2), lithium Sodium 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. SiO refers to silicon containing a silicon-rich portion. It refers to powder of elemental oxide, SiO y It can also be written as (2>y>0). For example, SiO , a material containing one or more selected from Si2O3, Si3O4, or Si2O, It also contains a mixture of silicon powder and silicon dioxide (SiO2). SiO2 also contains other elements (carbon, nitrogen, etc.). May contain metals such as iron, aluminum, copper, titanium, calcium, and manganese. Single crystal Si, amorphous Si, polycrystalline Si, Si2O3, Si3O4, Si2O, It refers to a material containing multiple materials selected from SiO2, and SiO is a colored material. There is no SiO x (X is 2 or more), it is colorless and transparent or white and can be distinguished. However, after a secondary battery is fabricated using SiO as the secondary battery material, repeated charging and discharging If SiO is oxidized by repeated heating, it may change into SiO2.

[0058] In addition, the negative electrode active material is a composite nitride of lithium and transition metals, which has a Li3N structure. Li 3-x M x N (M=Co, Ni, Cu) can be used. For example, Li 2.6 Co 0.4 N3 has a large charge / discharge capacity (900mAh / g, 1890mAh / cm 3 ) And preferable.

[0059] When a composite nitride of lithium and a transition metal is used, the negative electrode active material contains lithium ions, The positive electrode active material is a combination of materials such as V2O5 and Cr3O8 that do not contain lithium ions. It is preferable that a material containing lithium ions is used as the positive electrode active material. By first removing the lithium ions contained in the positive electrode active material, As the lithium-transition metal nitride, a complex nitride of lithium and a transition metal can be used.

[0060] In addition, a material that undergoes a conversion reaction can also be used as the negative electrode active material. , cobalt oxide (CoO), nickel oxide (NiO), iron oxide (FeO), etc. A transition metal oxide that does not undergo an alloying reaction with the negative electrode active material may be used. Further materials that undergo a reaction include Fe2O3, CuO, Cu2O, RuO2, and Cr2O Third order oxide, CoS 0.89 , NiS, CuS and other sulfides, Zn3N2, Cu3N, G Nitrides such as e3N4, phosphides such as NiP2, FeP2, CoP3, FeF3, BiF3 This also occurs with fluorides such as those mentioned above. Since the potential of the fluorides is high, they are not suitable for use as positive electrode active materials. That's fine.

[0061] In addition to the above-mentioned negative electrode active material, the negative electrode active material layer contains a binder for improving the adhesion of the active material. The negative electrode active material layer may contain a binder, a conductive auxiliary agent for increasing the conductivity of the negative electrode active material layer, and the like.

[0062] Then, three pairs of positive electrodes 101 and negative electrodes 102 are stacked together, and the positive electrodes are joined together and the negative electrodes are joined together. That is, as shown in FIG. 1(E), a negative electrode, a separator, a positive electrode, a separator, a negative electrode, a separator, The stack is made up of a cathode, a positive electrode, a separator, a negative electrode, a separator, and a positive electrode in that order. In this case, the negative electrodes are electrically connected to each other by ultrasonic bonding or the like.

[0063] The separator 103 is made of cellulose (paper) or polypropylene with holes. An insulator such as polyethylene can be used.

[0064] Next, in order to form the exterior body 107 that houses the combination of the positive electrode, separator, and negative electrode, In this embodiment, a laminated film having two circular openings is prepared. Use one sheet.

[0065] The film for forming the exterior body 107 is a metal film (aluminum, stainless steel, nickel, Nickel steel, gold, silver, copper, titanium, nichrome, iron, tin, tantalum, niobium, molybdenum, zinc metal foils (metals or alloys such as vanadium, zinc, etc.), plastic foils made from organic materials, Hybrid materials including films, organic materials (such as organic resins and fibers) and inorganic materials (such as ceramics) Lid material film, carbon-containing inorganic film (carbon film, graphite film) A single layer film selected from the following or a laminated film made up of a plurality of these is used.

[0066] In this embodiment, a laminated film having two circular openings is folded in the center to separate the two openings. The openings are overlapped and three sides are sealed with adhesive. First, the filter is opened to leave one side for adding electrolyte. The two sides of the film are sealed by thermocompression. The periphery of the opening is also sealed by thermocompression. The thermocompression bonding area 118b is formed and sealed. The electrode tab portion is exposed at the opening. Then, thermocompression bonding is performed in this state.

[0067] Then, a desired amount of electrolyte is poured into the film in a reduced pressure atmosphere or an inert atmosphere until the film becomes bag-shaped. Finally, drip the film onto the inside of the film that was left unheated. Then, thermocompression bonding is performed to form thermocompression bonding area 118a for sealing.

[0068] The electrolyte serves as a supporting electrolyte, allowing carrier ions to be transported and Representative examples of supporting electrolytes include LiPF6, L iClO4, LiAsF6, LiBF4, LiCF3SO3, Li(CF3SO2)2N These supporting electrolytes are used alone. They may be used alone or in any combination and ratio of two or more.

[0069] The solvent of the electrolyte is a material that allows carrier ions to be transported. As the solvent, an aprotic organic solvent is preferred. Representative examples of the aprotic organic solvent include: Ethylene carbonate (EC), propylene carbonate, dimethyl carbonate, diene Diethyl carbonate (DEC), γ-butyrolactone, acetonitrile, dimethoxyethane , tetrahydrofuran, etc., and one or more of these can be used. By using a polymer material that gels as a solvent for the electrolyte, safety against leakage etc. is improved. Furthermore, it is possible to make the secondary battery thinner and lighter. Examples include silicone gel, acrylic gel, acrylonitrile gel, and polyethylene glycol. Examples include oxide-based gels, polypropylene oxide-based gels, and fluorine-based polymer gels. In addition, a flame-retardant and non-volatile ionic liquid (room-temperature molten salt) was used as the solvent for the electrolyte. Or, by using multiple batteries, the internal temperature may rise due to an internal short circuit or overcharging of the secondary battery. Even if the battery is in a fluid state, it can prevent the secondary battery from exploding or catching fire. Ionic liquids are salts that have high ion mobility (conductivity). The ionic liquid contains an ethylmethylimidazolium (EMI) cation. Ionic liquid, or N-methyl-N-propylpiperidinium (PP 13 ) containing cations Examples include ionic liquids.

[0070] In addition, instead of the electrolyte solution, solid electrolytes containing inorganic materials such as sulfides and oxides, and P A solid electrolyte containing a polymer material such as EO (polyethylene oxide) can be used. When a solid electrolyte is used, there is no need to install a separator or spacer. Since the entire pond can be solidified, there is no risk of leakage, dramatically improving safety.

[0071] In this manner, the power storage unit 100 shown in FIG. 1A can be manufactured.

[0072] The power storage unit 100 has a terminal at the center, and the center of the secondary battery is fixed by thermocompression bonding. By doing so, it is possible to suppress the amount of deformation caused by deformation of the secondary battery. This eliminates the need for a specially designed circuit board, reducing the number of parts required.

[0073] In the first embodiment, an example of a square outer shape is shown, but this is not particularly limited, and it may be any shape having an opening in the center. The shape may be a rectangle with an opening in the center, a circle with an opening in the center, or an oval with an opening in the center. The shape of the opening provided in the exterior body is not limited to a circle, but may be a rectangle, a square, an ellipse, or any other shape. It may also be rectangular.

[0074] (Embodiment 2) In the first embodiment, an example in which the opening is circular is shown. In the present embodiment, shows an example of different opening shapes.

[0075] This embodiment differs from the first embodiment in the shape of the opening and the position of the terminal, that is, the shape of the positive electrode and the negative electrode. The parts in Figure 2 that are common to Figure 1 are the same except for the shape. The same reference numerals will be used in the description, and detailed descriptions will be omitted here for the sake of brevity. do.

[0076] FIG. 2A shows an example of a top view of the power storage unit 200. FIG. 2B shows a top view of the positive electrode 101. FIG. 2(C) shows the shape of the top surface of the separator 103. FIG. 2(D) shows the shape of the top surface of the negative electrode 102. Show the shape.

[0077] A power storage unit 200 of one embodiment of the present invention includes a positive electrode 101 and a cell 102 in an exterior body 107 having an opening. The battery includes at least a battery 103, a negative electrode 102, and an electrolyte.

[0078] In this embodiment, the exposed portion of the positive electrode 101 at the opening of the exterior body 107 is The position of the positive electrode tab portion and the negative electrode 102 portion (negative electrode tab portion) are shifted to prevent short circuit. It is designed to prevent this.

[0079] The opening of the exterior body 107 has a rectangular or square shape. A thermocompression bonding region 118b is formed so as to surround the insulating film 118.

[0080] 3 is a cross-sectional view showing the state where the power storage unit 200 is bent. 3 is a cross-sectional view taken along the line 1000 in FIG. 3, and the same reference numerals are used for the same parts as in FIG. 2. The negative electrode and separator housed in 107 are omitted. Illustrated.

[0081] When the power storage unit 200 is bent as shown in FIG. 3, the central portion and the thermocompression-bonded region 118b are The amount of change is smaller than that of the region 118a. The electric body 200 has a structure that is strong against bending.

[0082] In addition, since the power storage unit 200 has an opening in the center, the power storage unit 200 itself is partially bent. It is designed to be easy to use.

[0083] Also, as shown in Figure 3, there is a space in the center, so the lead wire is connected to this part. It is also possible to install a circuit board that is smaller than the opening of exterior body 107. When a plurality of positive electrodes 101 are stacked, the capacity can be increased and the thickness also increases. This increases the space in the center, allowing more elements and circuits to be installed in the center. In this way, the power storage unit 200 having an opening in the center can be used to The power storage unit can be configured to be able to be effectively utilized.

[0084] This embodiment mode can be freely combined with Embodiment Mode 1.

[0085] (Embodiment 3) In this embodiment, the power storage unit obtained in Embodiment 1 or 2 is mounted on an electronic device. An example of this case is shown in FIG.

[0086] The power storage unit 400 shown in FIG. 4(A) includes a socket 403 and a lead wire 40 connected to the positive electrode. 1 is connected to a lead wire 402 connected to the negative electrode.

[0087] Inside the socket 403, the positive electrode tab and the lead wire 401 are connected by welding, and the negative electrode tab and The lead wires 402 are connected by welding, and an insulator is provided between them to prevent short circuits. do.

[0088] In addition, a circuit to prevent overcharging is provided inside the socket 403, and each lead wire is connected to the It is also acceptable to do so.

[0089] An example of changing the bending direction is shown in Figure 4(B). The amount of change in the central portion is smaller than that in other portions. Therefore, the state of FIG. 4(A) is changed to FIG. Even if bending as shown in 4(B) is repeated, the deformation in the center is kept small, and the other parts The portion may be flexible.

[0090] The recesses or protrusions formed on the surface (or back) of the film by embossing The airbag is part of the wall of the sealing structure, forming a closed space with a variable volume. It can also be said that the recesses or protrusions of the film are formed as a bellows structure. In addition to embossing, which is a type of press processing, there are also processes that create relief (relief) on a part of the film. Any method that can form a thin film (f) is sufficient.

[0091] 4(A) and 4(B), a lead wire 401 connected to the positive electrode and a lead wire 402 connected to the negative electrode are shown. Although an example in which the lead wire 402 is taken out from different surfaces is shown, it is not particularly limited, and Alternatively, both lead wires 401 and 402 can be taken out.

[0092] A storage battery that uses a film as an exterior body is better suited to connecting multiple batteries in series or parallel rather than using a single battery. The batteries are connected in a series and a circuit is installed to prevent overcharging, etc., to form a single battery pack for use in electronic devices. Implement it in.

[0093] For example, a connector that can connect two power storage units 400 so that the centers of the two power storage units 400 overlap each other is provided between the two power storage units 400. If the center is set between 400, a series connection is possible. The upper and lower parts can be fixed so that they overlap, allowing electrical connection between them.

[0094] Furthermore, even when three or more power storage units 400 are stacked, they can be connected in series in the same manner. In addition, a battery pack can be fabricated by connecting a plurality of power storage units 400 in series. Even if the storage battery 400 is stacked, each battery is easily bent. This makes it possible to realize a battery pack that can be bent even when heated.

[0095] In addition, when providing lead electrodes, bending the lead electrodes before mounting reduces the area and space required. However, the power storage unit shown in this embodiment can omit the lead electrodes. When multiple storage batteries are mounted, they can be stored in a small space.

[0096] Another mounting example is shown in FIG. 4(C). In FIG. 4(C), the display panel and the power storage unit are overlapped. The display panel 410 has an opening in the center of the display area. 0 and a power storage unit 420 having an opening 412 so as to overlap the center of the power storage unit 420. The fixing members 411a, 411b, and 411c are made of screws, bolts, etc. It is desirable to use an insulator to prevent the terminals of the electric body from shorting out. If an insulating film is formed on the surface of the fixture, it can be used as a fixture.

[0097] Although the electrical connection structure between the power storage unit 420 and the display panel is not shown in FIG. , it is also possible to connect them through the opening 412.

[0098] In addition, when the display panel 410 having an opening is flexible, the power storage unit 4 The opening of the display panel 410 and the capacitor 420 can also be flexible. The openings in the holes can be used to fasten the plates to each other with fasteners 411a, 411b, and 411c. By fixing it in place, it is possible to create a durable electronic device.

[0099] The display panel 410 may also be a non-flexible panel.

[0100] The display elements used in the display panel include EL elements (EL elements including organic and inorganic materials, Organic EL elements, inorganic EL elements), LEDs (white LEDs, red LEDs, green LEDs, blue LEDs) ED, etc.), transistors (transistors that emit light according to the current), electron-emitting devices, liquid crystal Devices, electronic ink, electrophoretic devices, grating light valves (GLV), plasma displays Display (PDP), MEMS (Micro Electro Mechanical Systems) display element, digital micromirror device (DMD), DMS (digital micromirror shutter), IMOD (Interference Modulation) element, shutter MEMS display element using the optical interference method, MEMS display element using the electrowetting method display devices using piezoelectric ceramic displays and carbon nanotubes. In addition to these, there are also other types of counters that can be controlled by electrical or magnetic action. The display medium may have a variable resistance, brightness, reflectance, transmittance, etc. An example of such a display device is an EL display. An example of such a device is a field emission display (FED) or SED system. Flat panel display (SED: Surface-conduction Electro Examples of display panels using liquid crystal elements include LCDs. LCD displays (transmissive LCDs, semi-transmissive LCDs, reflective LCDs) LCD displays include projection LCDs, direct-view LCDs, and projection LCDs. An example of a display panel using electronic ink, electronic liquid powder, or electrophoretic elements Examples of such displays include electronic paper. To realize a spray, part or all of the pixel electrodes must function as reflective electrodes. For example, a part or all of the pixel electrodes may be made of aluminum, silver, etc. In this case, a memory circuit such as an SRAM may be provided under the reflective electrode. This can further reduce power consumption.

[0101] This embodiment mode can be freely combined with Embodiment Mode 1 or 2. Cut.

[0102] (Fourth embodiment) In this embodiment, a power storage unit obtained by using any one of Embodiments 1 to 3 is incorporated. An example of such an electronic device is shown below.

[0103] Examples of electronic devices that use power storage devices include head-mounted displays and goggle-type displays. display devices such as TVs (also called televisions or television receivers), desktop laptop and other personal computers, computer monitors, digital cameras, etc. digital cameras, digital video cameras, digital photo frames, electronic organizers, e-book terminals, Translators, toys, voice input devices such as microphones, electric shavers, electric toothbrushes, electronic razors High frequency heating devices such as microwave ovens, electric rice cookers, electric washing machines, electric vacuum cleaners, water heaters, electric fans, hair Dryers, air conditioning equipment such as humidifiers, dehumidifiers, and air conditioners, dishwashers, and dish dryers dryers, clothes dryers, futon dryers, electric refrigerators, electric freezers, electric refrigerator-freezers, for DNA storage Freezers, flashlights, power tools, smoke detectors, gas alarms, burglar alarms and other alarm systems, industrial equipment Industrial robots, hearing aids, cardiac pacemakers, X-ray machines, radiation detectors, electric massagers health and medical equipment such as dialysis machines and dialysis machines, mobile phones (also called mobile phones or mobile phone devices) ), portable game consoles, personal digital assistants, lighting equipment, headphones, stereos, remote controls Rollers, clocks such as table clocks and wall clocks, cordless telephone handsets, transceivers, pedometers, Portable or stationary sound reproducing devices such as calculators, digital audio players, pachinko machines, etc. Examples include large game consoles.

[0104] The power storage unit obtained by using any one of the first to third embodiments has a thin and flexible exterior. It is a film that is attached to a support structure having a curved surface, and is used to protect the support structure from a large radius of curvature. It can be deformed to follow the curved surface of the area.

[0105] In addition, flexible storage batteries can be mounted on the interior or exterior walls of houses and buildings, or on automobiles. It is also possible to incorporate it along the curved surface of the interior or exterior of the vehicle.

[0106] FIG. 5A shows an example of a mobile phone. The mobile phone 7400 has a housing 7401. In addition to the display unit 7402 incorporated in the The mobile phone 7400 is equipped with a speaker 7405, a microphone 7406, and the like. It has a body 7407.

[0107] FIG. 5B shows the mobile phone 7400 in a curved state. When the entire casing 0 is deformed by an external force and curved, the casing 7 provided inside the casing The state of the bent power storage unit 7407 is shown in FIG. The power storage unit 7407 is a laminated battery (also called a laminated battery or a film-covered battery). The power storage unit 7407 is fixed in a bent state. 07 has a lead electrode 7408 electrically connected to a current collector 7409. For example, An opening is provided in the film of the exterior body of the power storage unit 7407, and the power storage unit 7407 is bent. Furthermore, the mobile phone 7400 has a highly reliable configuration even when the SIM card is inserted. A slot for inserting a card and a connector for connecting a USB device such as a USB memory stick A section may be provided.

[0108] Figure 5(D) shows an example of a bendable mobile phone. If the mobile phone is bent in the shape shown in FIG. 5(E), it can be made into a bangle-type mobile phone. 100 includes a housing 7101, a display unit 7102, operation buttons 7103, and a power storage unit 7104. FIG. 5F shows a state of the power storage unit 7104 that can be bent. When the battery 104 is bent and worn on the user's arm, the housing is deformed and one part of the battery 7104 is The curvature of part or the whole changes. Specifically, the curvature radius is between 10 mm and 150 mm. Within this range, a part or the whole of the main surface of the housing or the power storage unit 7104 changes. 7104 has a lead electrode 7105 electrically connected to a current collector 7106. For example, an opening is provided in the film of the exterior body of the power storage unit 7104, and the power storage unit 7104 is bent. This structure allows the cable to maintain high reliability even when bent many times by changing the bending rate. As shown in Figure 5(D), the mobile phone is a device that can change into multiple shapes. To achieve this, at least a housing 7101, a display unit 7102, and a power storage unit 7103 are required. It is desirable that 104 be flexible.

[0109] In addition, the mobile phone 7100 has a slot for inserting a SIM card and a USB memory stick. A connector for connecting a USB device such as the above may be provided.

[0110] Another example of using a mobile phone is shown in Figure 5(D), where the mobile phone is folded in the center. If the center part of the mobile phone is further expanded, it can be made into the shape shown in Figure 5(G). The mobile phone is folded so that the ends overlap as shown in Figure 5(H) to make it smaller. It can be made small enough to fit in a user's pocket. Figures 5(D), 5(G), and 5(H) If only the deformation shown in FIG. 7 is observed, the power storage unit 7104 is not bent.

[0111] FIG. 6(A) shows an example of a vacuum cleaner. The inside of the vacuum cleaner has a dust collection space to suck up and store dust. Therefore, it is preferable that the space occupied by the power storage unit 7604 is as small as possible. and disposing a bendable capacitor 7604 between the outer surface and the dust collection space. is useful.

[0112] The vacuum cleaner 7600 includes an operation button 7603 and a power storage unit 7604. ) shows a state of a power storage unit 7604 that can be bent. The structure has an opening in the film, and is highly reliable when the power storage unit 7604 is bent. The power storage unit 7604 has a lead electrode 7601 electrically connected to the negative electrode and a positive electrode The lead electrode 7602 is electrically connected to the

[0113] The thin power storage unit 7604 is manufactured by the method for manufacturing the laminated secondary battery shown in Embodiment 1. It can be made by

[0114] The thin power storage unit 7604 has a laminate structure and is bent and fixed. The device 7600 has a display unit 7606 that displays the remaining power of a thin power storage unit 7604. The display surface of the display portion 7606 is curved to match the shape of the outer surface of the vacuum cleaner. The vacuum cleaner has a connection cord for connecting to an outlet, and a thin storage battery 7604. Once enough power is charged, you can use the vacuum cleaner without the cord. The thin power storage unit 7604 may be charged wirelessly without using a connection cord. Providing an opening in the film of the exterior body of the power storage unit 7604 increases reliability.

[0115] In addition, examples of electronic devices attached to a part of the human body are shown in Figs. 6(C), 7(A), and 7(B). ) shown.

[0116] The power storage unit obtained by using any one of the first to third embodiments can have a complex curved surface including a spherical surface. The device can be bent to fit any part of the human body that has

[0117] 6C shows an example of a wristband-type display device. The display device 7300 includes a display unit 73 04 and includes the power storage device of one embodiment of the present invention. The unit 7304 may be provided with a touch sensor, and may function as a mobile information terminal. It can also be done as follows.

[0118] The display surface of the display unit 7304 is curved, and images can be displayed along the curved display surface. The display device 7300 can also communicate with the display device 7300 by short-distance wireless communication according to a communication standard. The situation can be changed.

[0119] The display device 7300 is also equipped with an input / output terminal, and can be directly connected to other information terminals via a connector. It is also possible to charge the device via the input / output terminals. The charging operation may be performed by wireless power supply without using the input / output terminals.

[0120] The electronic device 7700 shown in FIG. 7A includes a band 7702 to be attached to a part of the human body. , flexible lighting (EL lighting using EL elements) and electrical connection via connector 7703 The lighting device has a power storage unit 7704 connected to the power storage unit 7704.

[0121] In FIG. 7(B), two electronic devices 7700 are attached to the elbows while walking or running at night. The electronic device 7700 and the power storage device 770 that is the power source for the electronic device are shown. 4 can bend in accordance with the movement of the arm.

[0122] Also, instead of attaching it with a band as shown in Figure 7(B), you can attach it to a part of your clothing. In addition to lighting, the device may also have a clock function, a temperature sensor, and the like.

[0123] In addition, by installing a bendable electricity storage device in a vehicle, it is possible to Next-generation clean energy vehicles such as electric vehicles (EV) and plug-in hybrid vehicles (PHEV) It can also be used in agricultural machinery, motorized bicycles including electrically assisted bicycles, Motorcycles, electric wheelchairs, electric carts, small or large boats, submarines, fixed-wing and rotary-wing aircraft Bending for moving objects such as aircraft, rockets, satellites, space probes, planetary probes, and spacecraft It is also possible to mount a power storage unit that can be used. [Explanation of symbols]

[0124] 100 Electricity storage unit 101 Positive electrode 102 Negative electrode 103 Separator 107 Exterior body 118a Thermocompression bonding area 118b Thermocompression bonding area 120 Electrolyte 200 Electricity storage unit 400 Electricity storage unit 401 Lead wire 402 lead wire 403 Socket 7100 Mobile Phone 7101 Housing 7102 Display section 7103 Operation button 7104 Electricity storage units 7105 Lead electrode 7106 Current collector 7300 display device 7304 Display section 7400 mobile phone 7401 Housing 7402 Display section 7403 Operation button 7404 External connection port 7405 Speaker 7406 Microphone 7407 Electric storage units 7408 Lead electrode 7409 Current collector 7600 Vacuum cleaner 7601 Lead electrode 7602 Lead electrode 7603 Operation button 7604 Electricity storage units 7606 Display section 7700 Electronic equipment 7702 band 7703 Connector 7704 Electricity storage units

Claims

[Claim 1] A bendable secondary battery, a first electrode, a second electrode, and a separator located between the first electrode and the second electrode; A first opening is provided in the center thereof. the first electrode has a plurality of second openings located around the periphery of the first opening; the second electrode has a plurality of third openings located around the periphery of the first openings; the second opening and the third opening have a different shape than the first opening; the second opening and the third opening are slit-shaped, a first region that functions as a terminal of the first electrode and a second region that functions as a terminal of the second electrode protrude into the first opening, The secondary battery has a shape that is point-symmetric with respect to the first opening.

Images