Energy storage device

Abstract

To provide a sheet-shaped power storage device that can be curved or bent in at least a uniaxial direction.SOLUTION: A power storage device includes a power storage element including: a plurality of sheet-shaped flexible positive electrodes each having one end fixed to a positive electrode tab, a plurality of sheet-shaped flexible negative electrodes each having one end fixed to a negative electrode tab, and a plurality of sheet-shaped flexible separators. The positive electrodes and the negative electrodes are overlapped on each other with each separator interposed between one positive electrode and one negative electrode. The power storage element is sealed in an exterior package with flexibility.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power storage device and a method for manufacturing the same.

Background Art

[0002] In recent years, lithium secondary batteries as power storage devices have been widely used as power sources for consumer electric devices such as information terminals typified by mobile phones and smartphones, and game machines.

[0003] In addition to having a long life and high capacity, such electric devices have an increasing need for a power storage device having sheet-like flexibility (flexibility) in order to achieve weight reduction, miniaturization, and ensure freedom in external design. By realizing a sheet-like power storage device having flexibility, for example, it can be installed in curved or bent parts or thin parts such as the band part of a wristwatch, clothes, and thin electric devices.

[0004] Conventional lithium secondary batteries, which are non-aqueous secondary batteries, generally have a positive electrode in which a positive electrode mixture containing a positive electrode active material that occludes and releases lithium ions is coated on both sides of a sheet-like positive electrode current collector made of aluminum or the like, and a negative electrode in which a negative electrode mixture containing a negative electrode active material that occludes and releases lithium ions is coated on both sides of a sheet-like negative electrode current collector made of copper or the like. These positive and negative electrodes are formed into a wound body by sandwiching a separator and winding a plurality of them, and a positive electrode tab and a negative electrode tab are respectively connected to predetermined portions of the positive and negative electrodes, and this is enclosed together with a non-aqueous electrolyte in an exterior body having a fixed shape such as a cylindrical, rectangular, or coin type. Although the positive electrode, separator, and negative electrode are each flexible members, after forming the wound body and enclosing it in a container, the shape is fixed and it cannot be freely bent. ​​​​​​​​​​​​Such flexibility is completely lost. Therefore, lithium secondary batteries are not able to bend or flex. It is not possible to give it the freedom to do so, and lithium secondary batteries are not used in the curved or bent parts of electrical equipment. It is difficult to install a pond.

[0005] Therefore, research into solid-state secondary batteries, such as those disclosed in Patent Document 1, is becoming increasingly popular. Solid-state rechargeable batteries replace conventional non-aqueous electrolytes with inorganic or organic solid electrolytes. The structure is as follows: positive electrode active material, solid electrolyte, negative electrode active material, and negative electrode current collector on the positive electrode current collector. It has a body and achieves flexibility by making the entire structure thin. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2007-123081 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, solid-state rechargeable batteries also require a thin electrolyte layer, and solid-state rechargeable batteries cannot be bent or flexed. This presents a problem in that short circuits between the positive and negative electrodes are likely to occur. In particular, solid-state secondary batteries Because the pond is formed entirely of solid material, repeated bending of the battery can cause the film to peel off and... Cracks occur in each film, making it easy to construct a sheet-like battery. There isn't one.

[0008] Furthermore, solid electrolytes used in solid-state secondary batteries have various challenges, and are not yet in practical use. do not have.

[0009] Therefore, one aspect of the present invention uses a conventional non-aqueous electrolyte without using a solid-state secondary battery. By utilizing the structure of a non-aqueous secondary battery, it is possible to bend or flex in at least one axial direction. To provide a sheet-shaped energy storage device. [Means for solving the problem]

[0010] One aspect of the present invention is a flexible sheet-like material, each having one end fixed to a positive electrode tab. Multiple positive electrodes and multiple flexible sheet-like structures, each with one end fixed to a negative electrode tab. The energy storage element has a negative electrode and a plurality of flexible sheet-like separators, and positive The electrodes and negative electrodes overlap alternately with one of several separators in between, and the energy storage element is flexible. It is an energy storage device enclosed in an outer casing having [a certain characteristic].

[0011] Furthermore, one aspect of the present invention relates to a flexible sheath, each having one end fixed to a positive electrode tab. A flexible sheet-like structure comprising multiple positive electrodes in a T-shape, with one end of each fixed to a negative electrode tab. The energy storage element has multiple negative electrodes and a flexible sheet-like separator, and positive The electrodes and negative electrodes overlap alternately with a separator in between, and the energy storage element has a flexible outer layer. This is an energy storage device enclosed within the casing.

[0012] The positive electrode consists of a flexible sheet-like (strip-like) positive electrode current collector and positive electrode active material on both sides thereof. It has at least a positive electrode mixture layer. Therefore, the positive electrode itself is also in sheet form and is flexible. Similarly, the negative electrode consists of a flexible, sheet-like negative electrode current collector and negative electrode active materials on both sides thereof. It has at least a negative electrode mixture layer containing a certain substance. Therefore, the negative electrode itself is also in sheet form and flexible. It has properties. However, this applies when the positive electrode mixture layer or the negative electrode mixture layer consists only of their respective active materials. The positive electrode mixture layer or negative electrode mixture layer refers to a layer consisting only of the respective active material. By stacking the negative electrode and the positive electrode with a separator in between, a charge / discharge capacity can be formed.

[0013] The charge / discharge capacity can be increased by alternately stacking positive and negative electrodes with a separator in between. This is possible. On the other hand, if the number of layers is increased, the thickness of the energy storage element increases, thus affecting the structure of the present invention. Even if the modification is carried out, bending or flexing becomes difficult. Also, the weight of the energy storage element naturally increases. Therefore, it may become difficult to apply to portable electrical devices. The number of layers should be designed appropriately according to the desired charge / discharge capacity and the degree of lightness or flexibility. For example, the total number of layers of positive and negative electrodes, each with a thickness of 20 μm or more and 100 μm or less. The number of sheets should be 5 or more, preferably 10 to 50.

[0014] The separator separates the positive and negative electrodes and maintains the electrolyte, ensuring ionic conductivity between the positive and negative electrodes. In addition to having conventional functions such as maintaining, when an external force is applied, the positive electrode The surface that contacts the negative electrode has the function of sliding smoothly. Therefore, as a separator, it has the function of making contact It is preferable to use a material with low sliding friction (low coefficient of friction) relative to the positive or negative electrode. Furthermore, it is preferable to use non-adhesive materials. For example, polypropylene or polytetrafluoroethylene. Oroethylene (trade name: Teflon®), etc., can be used. Furthermore, this These materials may be used after a surface treatment has been applied to the surface to reduce physical or chemical sliding friction. stomach.

[0015] A flexible, sheet-like positive electrode has a positive electrode current collector made of a conductive material at one end. The positive tab is physically fixed. On the other hand, the other end is not fixed, and as a result the positive Only one end of the electrode is fixed to the positive electrode tab. Multiple sheet-like positive electrodes are laid flat on top of each other. Because the positive electrode tab is fixed to the row, multiple sheet-like positive electrodes fixed to the positive electrode tab are attached to the spine. It has a structure similar to a book or notebook, consisting of multiple sheets glued together. The positive electrode tab stores The electrical device may be directly routed to the outside of its casing, or it may be connected to other components, and the components It may be led out to the outside of the exterior body.

[0016] Similarly, a flexible sheet-like negative electrode has a negative electrode current collector at one end made of a conductive material. The negative electrode tab, which consists of [this material], is physically fixed to it. On the other hand, the other ends are not fixed, so the result Only one end of the negative electrode is fixed to the negative electrode tab. Multiple sheet-like negative electrodes are arranged so that they overlap. They are fixed to the negative electrode tabs parallel to each other. The negative electrode tabs are then led directly to the outside of the casing of the energy storage device. It may be extended, connected to other components, and the component may be led out to the outside of the casing.

[0017] The positive and negative electrodes, one end of which is fixed to a tab, form a charge / discharge capacity with a separator in between. The positive and negative electrodes are stacked alternately so that they overlap each other. The separator may consist of multiple sheets or a single continuous sheet.

[0018] The energy storage element having the above structure has overlapping sheet-like positive and negative electrode surfaces facing each other. When an external force is applied in the direction of the positive electrode, one end of the positive and negative electrodes is connected to the tab. Except for the one mentioned above, the positive and negative electrodes are not fixed, so they slide and move across the surface of the separator. It can be deformed in this way. For this reason, the energy storage element can be made using, for example, a laminate film. By enclosing it in a flexible outer casing, the energy storage device has flexibility in at least one axial direction. It is possible to form this. [Effects of the Invention]

[0019] To provide a sheet-like energy storage device that has high capacity and is flexible in at least one axial direction. It is possible. [Brief explanation of the drawing]

[0020] [Figure 1] A diagram illustrating an energy storage element. [Figure 2] A diagram illustrating an energy storage element. [Figure 3] A diagram illustrating an energy storage device. [Figure 4] A diagram illustrating an energy storage device. [Figure 5] A diagram illustrating the positive electrode. [Figure 6] A diagram illustrating the negative electrode. [Figure 7] A diagram illustrating electrical equipment. [Figure 8] A diagram illustrating electrical equipment. [Modes for carrying out the invention]

[0021] The embodiments will be described below with reference to the drawings. However, many of the embodiments differ. It is possible to implement it in any manner, without deviating from its purpose and scope. It will be readily apparent to those skilled in the art that the details can be modified in various ways. Therefore, the present invention The following embodiments are not to be interpreted as being limited to their contents.

[0022] In addition, in each figure described herein, the size of each component, the thickness of the film, or the area shall be clearly indicated. It may be exaggerated for that reason. Therefore, it is not necessarily limited to that scale. There isn't one.

[0023] (Embodiment 1) In this embodiment, a lithium-ion battery with high capacity and flexibility in at least one axial direction is used. Energy storage devices, such as the following type of battery, will be explained using Figure 1.

[0024] A lithium secondary battery is a secondary battery that uses lithium ions as carrier ions. Furthermore, carrier ions that can be used instead of lithium ions include na Alkali metal ions such as thorium and potassium, calcium, strontium, barium, etc. These include alkaline earth metal ions, beryllium ions, or magnesium ions.

[0025] Figure 1(A) shows a cross-section of an energy storage element illustrating the energy storage element of the energy storage device shown in this embodiment. This is a diagram. In this invention, the energy storage element explains the arrangement and connection structure of the positive and negative electrodes. These are terms used for convenience, and include at least positive electrode, negative electrode, separator, positive electrode tab and negative electrode This refers to a structure having tabs. In Figure 1(A), the energy storage element 100 has multiple sheet-like positive electrodes. 101, multiple sheet-like negative electrodes 103, multiple sheet-like separators 102, and a positive electrode It has a tab 104 and a negative electrode tab 105.

[0026] Although not shown in the diagram here, the positive electrode 101 consists of a positive electrode current collector made of a conductive material and on both sides thereof A positive electrode mixture layer containing a positive electrode active material that absorbs and releases thium ions, or consisting solely of a positive electrode active material. It has at least the following. Similarly, the negative electrode 103 has a negative electrode current collector made of a conductive material and its Negative electrode containing or consisting solely of a negative electrode active material that absorbs and releases lithium ions on both sides It has at least a polarity mixture layer.

[0027] The positive electrode 101 and negative electrode 103 used in the energy storage device of this embodiment are curved in at least one axial direction. It is a sheet-like electrode that is flexible and can be bent or flexed. Therefore, the positive electrode 101 is formed The positive electrode current collector is made of a flexible conductive material. The positive electrode mixture is formed on the positive electrode current collector. The layer curves or bends in accordance with the curvature or bending of the positive electrode current collector. Therefore, curvature or bending is possible. To ensure this is possible, the material selection and film thickness design should take into account mechanical strength and adhesion to the positive electrode current collector. Proceed as appropriate. This also applies to the negative electrode 103.

[0028] These sheet-like positive electrode 101 and negative electrode 103 are stacked with a separator 102 in between. By overlapping the positive electrode 101 and the negative electrode 103, a charge / discharge capacity can be formed. The combined area is directly reflected in the charge / discharge capacity. Therefore, when manufacturing a large-capacity energy storage device... In this case, the area of ​​the sheet-like positive electrode 101 and negative electrode 103 can be increased. On the other hand, energy storage Depending on the intended use of the device, the area of ​​the sheet-like electrode may be limited. In this case, the positive electrode is negative. A similar effect can be achieved by increasing the number of poles stacked.

[0029] In this embodiment, the charge and discharge capacity is determined by the positive electrode 101 and the negative electrode 10 with a separator in between. The effect is enhanced by stacking 3 alternately. On the other hand, if the number of layers is increased too much, the energy storage element Because the thickness of child 100 increases, even when the configuration of the present invention is implemented, curvature or bending will occur. It becomes more difficult. Also, since the weight of the energy storage element naturally increases, application to portable electrical devices becomes difficult. There is a risk that it will become difficult. Therefore, the number of stacks of positive electrode 101 and negative electrode 103 is determined by the charge and discharge that are formed. It is best to design it appropriately according to the capacity and the degree of lightness or flexibility. For example, if the thickness of each is A positive electrode 101 with a diameter of 20 μm or more and 100 μm or less, a negative electrode 103, and two separators make up the cross The number of layers stacked in the structure should be 5 or more, preferably 10 to 50. The body and the negative electrode current collector are each 10 μm thick, and the positive electrode mixture layer and the negative electrode mixture layer are each 100 μm thick. If the separator is 20 μm thick, the total thickness will be 240 μm. The number of layers is 50. In this case, the energy storage element will be 12 mm thick, so in order to ensure the flexibility of the energy storage element, multiple layers are needed. It is preferable to keep the number below this amount.

[0030] The separator 102 separates the positive electrode 101 and the negative electrode 103 and maintains the electrolyte between the positive and negative electrodes. In addition to having conventional functions such as ensuring ionic conductivity, when an external force is applied... When this occurs, the surfaces that come into contact with the positive electrode 101 and the negative electrode 103 have the function of sliding smoothly. The separator 102 has low sliding friction with respect to the positive or negative electrode it contacts. It is preferable to use a material with a coefficient, and it is also preferable to use a non-stick material. Example For example, polypropylene or polytetrafluoroethylene can be used. Furthermore, Even if these materials are used with a surface treatment that reduces physical or chemical sliding friction on their surface, good.

[0031] In this embodiment, the separator 102 has a planar shape with a positive electrode 101 and a negative electrode 103. It has a sheet-like shape that is roughly the same in form, and is roughly parallel to the positive electrode 101 and the negative electrode 103. They are arranged between the positive and negative electrodes. Therefore, the positive electrode formed by the positive electrode 101 and the negative electrode 103 Use as many separators 102 as there are pole-to-negative electrode spaces.

[0032] The planar shape of the sheet-like positive electrode 101 is, for example, a long rectangle. However, the planar shape is for energy storage. The type of electrical equipment and other devices that will be mounted on the device can be freely selected depending on their intended use. For example, trapezoidal However, any two-dimensional shape with a certain area, such as a triangle, polygon, circle, or ellipse, will suffice. At one end of the positive electrode 101, the positive electrode current collector is physically connected to the positive electrode tab 104 made of a conductive material. It is fixed to the target. If the planar shape of the positive pole 101 is, for example, a rectangle, then one of its shorter sides. This can be used as the end. Even with other planar shapes, multiple positive electrodes 101 can be partially To secure it, any point can be designated as one end. On the other hand, the other ends are fixed Because it is not fixed, as a result only one end of the positive electrode 101 is fixed to the positive electrode tab 104.

[0033] In this way, multiple sheet-like positive electrodes 101 overlap each other, and positive electrode tabs 10 are arranged parallel to each other. Because they are fixed and bundled together at 4, multiple sheet-like positive electrodes 1 fixed to the positive electrode tab 104 01 has a structure similar to a book or notebook, consisting of multiple sheets glued to the spine.

[0034] Similarly, the negative electrode 103 has a negative electrode tab 1 at one end, where the negative electrode current collector is made of a conductive material. 05 is physically fixed. On the other hand, the other end is not fixed, resulting in negative electrode 1 Only one end of 03 is fixed to the negative electrode tab 105. Multiple sheet-like negative electrodes 103 overlap. They are fixed and bundled to the negative electrode tab 105 in parallel to each other.

[0035] The positive terminal tab 104 and the negative terminal tab 105 are connection terminals for inputting and outputting power, respectively These function as positive and negative terminals. Therefore, the positive tab 104 and the negative tab 105 are A conductive material with low resistance is used. Furthermore, an energy storage device having a positive electrode tab 104 and a negative electrode tab 105 is also used. Since the entire element 100 is immersed in an electrolyte (not shown), it is made of a material that is non-reactive to the electrolyte. Materials are used. For example, stainless steel, gold, or platinum can be used for the positive electrode tab 104 and the negative electrode tab 105. Metals such as zinc, iron, copper, aluminum, and titanium, and alloys thereof can be used. The positive electrode tab 104 and the negative electrode tab 105 are directly led out to the outside of the casing of the energy storage device. It is permissible to connect it to other conductive components, and to lead those other conductive components out of the casing. That's good too.

[0036] As described above, each end is fixed to the positive electrode tab 104, and the flexible sheet-like structure Multiple positive electrodes 101 and flexible electrodes, each with one end fixed to a negative electrode tab 105. A structure in which multiple sheet-like negative electrodes 103 are stacked alternately with a separator 102 in between. The energy storage element 100 has, therefore, the energy storage element 100 and the energy storage device having it have at least It can be flexible in one axial direction. That is, the positive electrode 101 of the energy storage element 100, the separator The electrode 102 and the negative electrode 103 are not fixed to each other, and the positive electrode 101 and the negative electrode 103 are, Since it is only in surface contact with the separator 102, when an external force is applied, each The flexible positive electrode 101 and negative electrode 103 slide across the surface of the separator 102. It can move in a direction that absorbs or mitigates force. Also, during this movement, the positive electrode 101 and the negative electrode Since both pole 103 and separator 102 are flexible sheets, It deforms when subjected to an external force. Therefore, the stacked structure of positive electrode 101, negative electrode 103, and separator 102 Because the structure as a whole bends or flexes in response to external forces, the energy storage element 100 is at least It can also have flexibility in one axis direction.

[0037] Uniaxial direction refers to the plane in which the positive electrode 101, negative electrode 103, and separator 102 are superimposed on each other. It refers to a vertical direction, and at least one axis direction refers to a direction that includes that vertical direction. That is, A force is applied to the generally sheet-shaped energy storage element 100 according to this embodiment from above or below. In some cases, the energy storage element 100 will bend or curve upward or downward in response to the applied force. Furthermore, if a torsional force is applied to the energy storage element 100, the energy storage element 1 will react accordingly. This means that 00 can also deform in the twisting direction.

[0038] For example, in Figure 1(B), when a force is applied to the energy storage element 100 from below, the energy storage element This shows the bent state of the child. In this case, the positive electrode 101, the negative electrode 103, and the separator 102 are As it is pushed upward in an arc, the positive electrode 101 is in contact with the separator 102. It moves to the left while sliding along the surface, while the negative electrode 103 is in contact with the separator 102. It moves to the right while sliding along the surface. Therefore, the energy storage element 100 takes on an upward-convex curved shape. It deforms. The flexibility of the energy storage element is such that it absorbs or mitigates external forces through such movement. In addition to being equipped with these features, a high charge / discharge capacity is maintained.

[0039] Here, the spacing between the positive electrode tab 104 and the negative electrode tab 105 is approximately fixed. Therefore, Even when an external force is applied to the energy storage element 100, the positive electrode tab 104 and the negative electrode tab 105 The distance is approximately constant. Therefore, the positive electrode 101 is with the negative electrode tab 105, or the negative electrode 103 is with the positive electrode tab 105. The electrode tab 104 makes contact and does not cause an electrical short circuit. Also, the positive electrode tab 104 and the negative electrode tab As the distance to 105 increases significantly, the overlapping region between the positive electrode 101 and the negative electrode 103 is reduced. The charge / discharge capacity is not significantly reduced, and the positive electrode 10 bundled by the positive electrode tab 104 The negative electrode 103, which is bundled with the negative electrode tab 105, separates, and the overlapping portion is lost. None of them.

[0040] Furthermore, the shape of the energy storage element 100 once it has been bent depends on the selection of materials for the positive electrode, negative electrode, etc. that make up the energy storage element. Depending on the selection, it can be restored to its original shape.

[0041] In addition, as an embodiment different from this one, the energy storage element 100 does not use the separator 102. In this embodiment, the energy storage element 100 is bent or curved, and a liquid electrolyte is inserted between them. By solidifying it, flexibility is lost, but a curved or bent shape is formed. A power storage device in the shape of can be manufactured.

[0042] Therefore, the energy storage element 100 is connected to the overlapping sheet-like positive electrode 101 and negative electrode 103 from the outside. When force is applied, the ends of the positive electrode 101 and the negative electrode 103 are the positive electrode tab 104 or the negative electrode tab, respectively. Except for one end connected to the pole tab 105, it is not fixed, so the positive pole 101 and the negative pole are not fixed. The pole 103 can be deformed by sliding along the surface of the separator 102. Therefore, the energy storage element 100 is sealed in a flexible outer casing made of, for example, laminate film. By doing so, it is possible to form an energy storage device that is flexible in at least one axial direction.

[0043] This embodiment can be implemented in appropriate combination with other embodiments.

[0044] (Embodiment 2) In this embodiment, the multiple separators in the energy storage element shown in Embodiment 1 are arranged in a series An example of using this as a separator will be explained using Figure 2.

[0045] Figure 2(A) illustrates the energy storage element 200 of the energy storage device shown in this embodiment. This is a cross-sectional view. In Figure 2(A), the energy storage element 200 has multiple sheet-like positive electrodes 201, Multiple sheet-like negative electrodes 203, a common single separator 202, and a positive electrode tab 204 It has a negative electrode tab 205.

[0046] The structure of the energy storage element 200 is the same as the structure of the energy storage element 100 described in Embodiment 1, However, it differs in that the separator 202 is a single, continuous sheet.

[0047] In other words, one end of each of the multiple flexible sheet-like positive electrodes 201 is fixed to the positive electrode tab 204. On the other hand, one end of each of the multiple flexible sheet-like negative electrodes 203 is fixed to the negative electrode tab 205. These multiple positive electrodes 201 and multiple negative electrodes 203 are connected by a single separator 20. The layers are stacked alternately with 2 in between. Separator 202 is shown in Figure 2(A). As shown, the cross-section is arranged in a meandering manner between the positive electrode 201 and the negative electrode 203. ru.

[0048] Thus, even when the separator 202 is made into a single continuous sheet, Figure 2(B As shown in ( ), the flexibility of the energy storage element 200 can be ensured. For example, the energy storage element 20 When an external force is applied from below 0, the positive electrode 201 and the negative electrode 203 are separated by separator 2 It slides along the surface of 02, moving either to the right or to the left. Separator 202 is also possible. Because it is a flexible sheet, it will bend upwards in response to external forces, but the separator 202 has a low coefficient of sliding friction with the positive electrode 201 and the negative electrode 203, and is also non-sticky, therefore positive There is no change in response to the slippage of pole 201 or negative pole 203.

[0049] As described above, the energy storage element 200 in this embodiment is also flexible, similar to Embodiment 1. The structure has properties. In particular, in the structure shown in this embodiment, the separator 202 is Because it is a single unit, it faces the end that is fixed to the positive tab 204 or the negative tab 205. The ends of the positive electrode 201 and negative electrode 203 located in that position are enclosed in the separator 202. Therefore, The positive electrode 201 is in contact with the negative electrode tab 205, or the negative electrode 203 is in contact with the positive electrode tab 204, and electrically... It is possible to structurally prevent short circuits.

[0050] This embodiment can be implemented in appropriate combination with other embodiments.

[0051] (Embodiment 3) In this embodiment, the energy storage device using the energy storage element shown in Embodiment 1 or Embodiment 2 is This will be explained using Figures 3 and 4.

[0052] Figures 3(A) and (B) show the energy storage element 100 shown in Embodiment 1, or in Embodiment 2. This is a bird's-eye view illustrating an energy storage device that has the shown energy storage element 200 inside.

[0053] Figure 3(A) shows the initial shape of the energy storage device 400, which is not curved or bent. In this configuration, the energy storage device 400 is a thin, rectangular sheet with a long side and a short side. On the opposing short sides are positive electrode tabs 402a and 402a, respectively, which are led out from inside the energy storage device 400. A negative electrode tab 402b is provided. Inside the energy storage device 400 is an embodiment of Embodiment 1 or an embodiment of The energy storage elements 100 and 200 shown in Form 2 are sealed together with the electrolyte. Positive electrode tab 40 2a and the negative electrode tab 402b are integrated with the positive electrode tab or negative electrode tab of the energy storage element, respectively. or connected as a separate component.

[0054] The energy storage device 400 encloses the energy storage element and electrolyte in an outer casing 401. 1 is a flexible bag-shaped container that houses the energy storage elements 100, 200 and the electrolyte in a sealed state. Any material would suffice, but it must have a certain strength as the outer casing for the sheet-like energy storage device 400. Furthermore, it is also required that the container be resistant to the electrolyte solution it will contain. It can be made of polyethylene, polypropylene, polycarbonate, etc. as the outer casing 401. Aluminum, stainless steel, etc. are applied to the inner surface of a film made of materials such as ionomer and polyamide. A highly flexible metal thin film such as rosin, copper, or nickel is provided, and an outer casing is further placed on the metal thin film. A three-layer structure with an insulating synthetic resin film such as polyamide resin or polyester resin on the outer surface. A laminate film can be used. By using such a three-layer structure, electrolysis It blocks the permeation of liquids and gases, ensures insulation, and also has electrolyte resistance.

[0055] The solute in the electrolyte is a material that contains carrier ions. Typical examples of solutes in an electrolyte include , LiClO4, LiAsF6, LiBF4, LiPF6, Li(C2F5SO2)2N Examples of lithium salts include the following.

[0056] Furthermore, the carrier ions include alkali metal ions other than lithium ions, and alkaline earth metal ions. In the case of ions, beryllium ions, or magnesium ions, the solute of the electrolyte is as follows: In the lithium salts, instead of lithium, alkali metals (for example, sodium or potassium) can be used. (e.g., strontium, barium), alkaline earth metals (e.g., calcium, strontium, barium), Lilium or magnesium may be used.

[0057] Furthermore, a material capable of transporting carrier ions is used as the solvent for the electrolyte. As the medium, an aprotic organic solvent is preferred. Typical examples of aprotic organic solvents are ethylene carbonate (EC), propylene carbonate, dimethyl carbonate, di Ethyl carbonate (DEC), γ-butyrolactone, acetonitrile, dimethoxyethanol These include tetrahydrofuran, and one or more of these can be used. By using a polymer material that gels as the solvent for the electrolyte, safety against leakage, etc. The effect increases. In addition, it becomes possible to make lithium secondary batteries thinner and lighter. Typical examples of these materials include silicone gel, acrylic gel, acrylonitrile gel, and poly Examples include ethylene oxide, polypropylene oxide, and fluorinated polymers. Also, electricity As the solvent for the dissolution, one or more flame-retardant and non-volatile ionic liquids (room-temperature molten salts) are used. By using multiple batteries, internal short circuits and overcharging can cause the internal temperature of lithium secondary batteries to rise. This also prevents lithium-ion batteries from rupturing or catching fire.

[0058] In Figure 3(A), the energy storage device 400 is rectangular in plan view, but it can also be trapezoidal, polygonal, circular, or elliptical. Any shape with a certain area can be designed and implemented as needed. .

[0059] Furthermore, in Figure 3(A), the positive electrode tab 402a and the negative electrode tab 402b are provided on opposite sides. Although they are positioned as such, the power storage elements are routed through wiring and arranged side by side along the same edge. It's also possible.

[0060] Next, Figure 3(B) shows the energy storage device 400 in a curved or bent state. Therefore, the energy storage device 400 is curved so that it is convex upward on the positive electrode tab 402a side, and the negative electrode tab 4 On the 02b side, it is curved so as to be convex downwards. Even with this curvature, the energy storage device 4 The energy storage element built into 00 is roughly left and right, as described in Embodiment 1 or Embodiment 2. Because the positive or negative electrode slides in the direction (the direction of the line segment connecting the positive and negative electrode tabs), It can bend while maintaining its discharge capacity. Therefore, the stacked structure of the positive and negative electrodes inside is Because they slide and conform to the curvature, the energy storage device 400 takes the shape shown in Figure 3(B). It can bend in this manner.

[0061] Note that the energy storage device 400 shown in this embodiment is in the vertical direction in Figures 3(A) and (B). In addition to curvature or bending in a uniaxial direction, it can also accommodate a certain degree of twisting. This is because the positive and negative electrodes are open at all but one end, ensuring freedom of movement. .

[0062] Next, the internal structure of the energy storage device 400 in this embodiment is shown in Figures 4(A) and (B). We will explain using this method.

[0063] Figure 4(A) is a cross-sectional view of the energy storage device 400, showing a magnified view of the area near the positive electrode. (Positive electrode section) Since the part and the negative electrode have roughly symmetrical structures in the schematic diagram, the negative electrode part is not shown. Omit it.

[0064] The energy storage device 400 has an energy storage element 404 enclosed inside the outer casing 401. As previously described, 4 is a configuration in which positive and negative electrodes are stacked alternately with a separator in between. Multiple positive electrodes are connected to the positive electrode tab 403, and multiple negative electrodes (not shown in the diagram) are connected to the negative electrode tab, with one end of each fixed to the positive electrode tab. It is specified. The positive electrode tab 403 is led out to the outside of the casing 401. Figure 4(A) Therefore, the positive electrode tab 403, which connects to multiple positive electrodes, connects to other positive electrode tabs 402, and the positive electrode tab 402 is led out to the outside of the outer casing 401. However, this is not the only way to lead the tab out to the outside. Alternatively, for example, the positive electrode tab 403 and the positive electrode tab 402 may be led out to the outside as a single unit. Furthermore, one or more other conductive members are provided between the positive electrode tab 403 and the positive electrode tab 402 to provide electrical conductivity. A more direct connection can be made. The same applies to the negative terminal.

[0065] A support plate 406 is provided on the lower surface of the energy storage element 404. The support plate 406 has a positive electrode tab. It is physically connected to the bottom of 403 and the negative electrode tab (not shown). A support plate 406 is provided. This allows the positive and negative electrode tabs to be fixed, preventing the energy storage element 404 from bending. Alternatively, even if the tab is bent, the distance between the positive and negative electrodes can be roughly fixed. Therefore, an electrical short circuit occurs when the positive electrode and the negative electrode tab, or the negative electrode and the positive electrode tab, come into contact. There is no risk of this happening. Also, if the gap between the positive and negative electrode tabs becomes too wide, the outer casing 40 There is no risk of losing the overlap between the positive and negative electrodes within component 1.

[0066] Furthermore, the positive electrode, negative electrode, separator, and outer casing 401 that constitute the energy storage element 404 are each posable. Because they are flexible, depending on the choice of these materials, they will bend due to gravity, etc., in their initial state. Therefore, the flat sheet shape may not be maintained. For this reason, the support plate 406 is connected to the energy storage element 40 By providing it on the lower surface of 4, the energy storage element 404 can be supported.

[0067] The support plate is made of a material that minimizes deflection due to its own weight and the fixing of the energy storage element 404, and is also intentionally designed to minimize deflection. It consists of a flexible material that bends or flexes when subjected to a specific bending action. As long as the conditions are met In this case, it may be either a conductive material or an insulating material. For example, a copper plate having a predetermined thickness may be used. It may also be rubber having a specified strength. If a conductive material is used for the support plate 406, To secure the electrode tabs and negative electrode tabs, and to prevent short circuits between them, at least the fixing portion An insulating material needs to be inserted. Also, the support plate 406 has a metal core and an insulating material covering it. It may be a border material, or a structure having a movable part in at least one axial direction may be used.

[0068] The outer casing 401, which encloses the energy storage element 404 and the electrolyte 405, contains them in a sealed state. Any flexible, bag-like container that can be housed inside would suffice, but a sheet-like power storage device that can be bent or flexed would be fine. The exterior of the 400 unit has a certain level of strength. Furthermore, it is designed to withstand the electrolyte solution contained within. It is also required that it be resistant to electrolytes. As the outer casing 401, for example, Materials such as polyethylene, polypropylene, polycarbonate, ionomer, and polyamide. On top of the insulating film 401c, aluminum, stainless steel, copper, nickel, etc., which have excellent flexibility A thin metal film 401b is provided, and a polyamide resin is used as the outer surface of the exterior body on the thin metal film. A three-layer laminate structure with an insulating synthetic resin film 401a such as lipids or polyester resins. A film can be used. By using such a three-layer structure, the permeability of electrolyte and gas is reduced. It provides insulation, blocks current, and is also resistant to electrolytes.

[0069] Figure 4(B) is a cross-sectional view of a different energy storage device 400 than that of Figure 4(A), and is similar to Figure 4(A). This is a magnified view of the vicinity of the positive electrode. The positive and negative electrode regions are roughly symmetrical in the schematic diagram. Since this is a structural diagram, the negative electrode portion is omitted from the illustration.

[0070] In Figure 4(B), an insulating material is used for the support plate 406, and the positive electrode tab 403 is on the support plate 406. The positive electrode tab 402 is led to the outside of the outer casing 401 via the wiring 407 provided therein, and electricity Connect directly. Wiring 407 comes into direct contact with electrolyte 405, so the reaction with electrolyte 405 is It is necessary to select a conductive material that is less prone to defects. For example, stainless steel can be used for wiring 407. Metals such as gold, platinum, zinc, iron, copper, aluminum, and titanium, and alloys thereof are used. This is possible. Note that wiring 407 is except for the terminal portion that connects to the positive tabs 402 and 403. It may also be covered with an insulating material.

[0071] In the structure shown in Figure 4(B), the positive electrode tab 402 is connected to the support plate 4 via the wiring 407. It is connected to 06 and is not in direct contact with the energy storage element 404, and is therefore located outside the outer casing 401. When a force is applied to the positive electrode tab 402, the force is not directly applied to the energy storage element 404. It is possible.

[0072] This embodiment can be implemented in appropriate combination with other embodiments.

[0073] (Embodiment 4) In this embodiment, the energy storage element described in Embodiments 1 to 3 is used as a lithium secondary battery. The structure and manufacturing method of the case will be described.

[0074] (Positive electrode and method for manufacturing the same) First, the positive electrode and its manufacturing method will be described. Figure 5(A) is a cross-sectional view of the positive electrode 500. Yes. The positive electrode 500 has a positive electrode mixture layer 502 formed on the positive electrode current collector 501.

[0075] The positive electrode current collector 501 can be made of stainless steel, gold, platinum, zinc, iron, copper, aluminum, titanium, etc. Highly conductive materials such as metals and alloys thereof can be used. Elements that improve heat resistance, such as titanium, neodymium, scandium, and molybdenum, are added. Aluminum alloys can be used. Furthermore, they react with silicon to form silicides. It may be formed with a metallic element that reacts with silicon to form a silicide. These include zirconium, titanium, hafnium, vanadium, niobium, tantalum, and chromium. These include molybdenum, tungsten, cobalt, nickel, etc. The positive electrode current collector 501 is foil-shaped. Appropriate shapes such as plate-like (sheet-like), mesh-like, perforated metal-like, expanded metal-like, etc. It can be used.

[0076] The positive electrode active material used in the positive electrode mixture layer 502 is capable of inserting and removing lithium ions. Materials can be used, for example, olivine-type crystal structure, layered rock salt-type crystal structure, or Examples include lithium-containing composite oxides having a spinel-type crystal structure.

[0077] Examples of lithium-containing composite oxides with an olivine-type structure include those with the general formula LiMPO4(M is A composite (one or more of Fe(II), Mn(II), Co(II), Ni(II)) Oxides are one example. Typical examples of the general formula LiMPO4 include LiFePO4 and LiNi PO4, 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 is 1 or less, 0 < a < 1, 0 < b < 1), LiFe c Ni d Co e PO4, LiFe c [[ID=三十二]]Ni d Mn e PO4, LiNi c Co d ! Mn e PO4 (c + d + e is 1 or less, 0 < c < 1, 0 < d < 1, 0 < e < 1), LiFe f Ni g [[ID=四十八]]Co h Mn i PO4 (f + g + h + i is 1 or less, 0 < f < 1, 0 < g < 1, 0 < h < 1, 0 < i < 1), etc. can be mentioned.

[0078] Especially, LiFePO4 preferably satisfies the requirements for a cathode active material, such as safety, stability, high capacity density, high potential, and the presence of lithium ions that can be extracted during initial oxidation (charging), in a balanced manner.

[0079] Examples of lithium-containing composite oxides having a layered rock salt-type crystal structure include lithium cobaltate (LiCoO2), LiNiO2, LiMnO2, Li2MnO3, LiNi 0. 0.2 O2, etc. of the NiCo system (general formula is LiNi x Co 1-x O2 (0 < x < 1) )、LiNi 0.5 Mn It should be noted that there may be some errors or unclear parts in the original text, and the translation is adjusted as accurately as possible based on the existing content.0.5 NiMn-based materials such as O2 (general formula: LiNi x Mn 1-x O 2(0 <x<1))、LiNi 1 / 3 Mn 1 / 3 Co 1 / 3 NiMnCo-based (N) such as O2 Also called MC. The general formula is LiNi x Mn y Co 1-x-y O2(x>0, y>0, x+ y<1)) is one example. Furthermore, Li(Ni 0.8 Co 0.15 Al 0.05 )O2, Li2MnO3-LiMO2 (M=Co, Ni, Mn) is another example.

[0080] In particular, LiCoO2 has a large capacity and is more stable in the atmosphere than LiNiO2. It is preferable because it has advantages such as being thermally stable compared to NiO2.

[0081] Examples of lithium-containing composite oxides having a spinel-type crystal structure include LiMn2O 4. Li 1+x Mn 2-x O4, Li(MnAl)2O4, LiMn 1.5 Ni 0.5 O Fourth place is one example.

[0082] Lithium-containing complex oxides having a spinel-type crystal structure containing manganese, such as LiMn2O4. A small amount of lithium nickel oxide (LiNiO2 or LiNi 1-x MO2(M=Co, A) Mixing (1, etc.) offers advantages such as suppressing manganese elution and inhibiting the decomposition of the electrolyte. It is preferable.

[0083] Furthermore, as the positive electrode active material, Li (2-j) MSiO4 (where M is Fe(II), Mn (II), Co(II), Ni(II) of one or more, 0 ≦ j ≦ 2) represented by the composite oxide can be used. General formula Li (2-j) As a representative example of MSiO4, Li (2-j ) FeSiO4, Li (2-j) NiSiO4, Li (2-j) CoSiO4, Li (2 -j) MnSiO4, Li (2-j) Fe k Ni l SiO4, Li (2-j) Fe k Co l SiO4, Li (2-j) Fe k Mn l SiO4, Li (2-j) Ni k Co l SiO 4, Li (2-j) Ni k Mn l SiO4 (k + l is 1 or less, 0 < k < 1, 0 < l < 1) , Li (2-j) Fe m Ni n Co q SiO4, Li (2-j) Fe m Ni n Mn q Si O4, Li (2-j) Ni m Co n Mn q SiO4 (m + n + q is 1 or less, 0 < m < 1, 0 < n < 1, 0 < q < 1), Li (2-j) Fe r Ni s Co t Mn u SiO4 (r + s + t + u is 1 or less, 0 < r < 1,​​​​​​x M2(XO4)3(A=Li, Na, Mg, M=Fe, M The general formula for n, Ti, V, Nb, Al, X = S, P, Mo, W, As, Si) Lithospermum-type compounds can be used. Examples of nastycone-type compounds include Fe2(MnO4) 3. Examples include Fe2(SO4)3 and Li3Fe2(PO4)3. Also, positive electrode active material For example, Li2MPO4F, Li2MP2O7, Li5MO4 (M=Fe, Mn) Compounds represented by the formula, perovskite-type fluorides such as NaF3 and FeF3, TiS2, M Metal chalcogenides such as oS2 (sulfides, selenides, tellurides), LiMVO4, etc. Lithium-containing composite oxides having an inverse spinel crystal structure, vanadium oxide system (V2O 5. V6O 13 Materials such as LiV3O8, manganese oxides, and organic sulfurs are used. It is possible.

[0085] Furthermore, the carrier ions include alkali metal ions other than lithium ions, and alkaline earth metal ions. In the case of ions, beryllium ions, or magnesium ions, the positive electrode mixture layer 502 is In the above lithium compounds and lithium-containing composite oxides, instead of lithium, Potassium metals (e.g., sodium and potassium), alkaline earth metals (e.g., calcium) (Strontium, barium, etc.), beryllium, or magnesium may also be used.

[0086] Furthermore, the positive electrode mixture layer 502 is not limited to being formed in direct contact with both sides of the positive electrode current collector 501. No. Between the positive electrode current collector 501 and the positive electrode mixture layer 502, The adhesion layer was created to improve adhesion with 02, and the surface irregularities of the positive electrode current collector 501 were smoothed out. A planarization layer for heat dissipation, a heat dissipation layer for heat dissipation, and a positive electrode current collector 501 or positive electrode mixture layer 502. Functional layers, such as stress-relieving layers, to alleviate stress may be formed using conductive materials such as metals. stomach.

[0087] Figure 5(B) shows the cathode mixture layer 502, which consists of particulate material capable of intercalating and deintercalating carrier ions. The electrode active material 503 and the multiple positive electrode active materials 503 are covered, and the positive electrode active material 503 is inside Plan view of the positive electrode mixture layer 502 when it is composed of graphene 504 packed into the part. Yes. Different graphene 504 layers cover the surfaces of multiple positive electrode active materials 503. Also, in some areas The positive electrode active material 503 may be exposed.

[0088] Here, graphene, in a narrow sense, is the horizontal layer of graphite, that is, composed of carbon. It is a carbon layer in which six-membered rings are continuous in the planar direction, or in other words, a single atomic layer of carbon having π bonds. This refers to a sheet of elementary molecules. In particular, when the carbon layer consists of two to 100 layers stacked together. While it is sometimes called multilayer graphene, here multilayer graphene is included in the category of graphene. It shall be defined as follows. Furthermore, graphene oxide refers to the compound obtained by oxidizing the above graphene. Furthermore, when graphene oxide is reduced to form graphene, the substances contained in the graphene oxide Not all of the oxygen is removed; some of it remains in the graphene. If present, the oxygen content should be between 2 atomic% and 20 atomic% of the total. The percentage is between 3 and 15 atomic percent.

[0089] Here, if graphene is multilayer graphene, then graphene obtained by reducing graphene oxide Having this feature, the interlayer distance of the graphene is 0.34 nm or more and 0.5 nm or less, preferably. 0.38 nm to 0.42 nm, more preferably 0.39 nm to 0.41 nm Below. Normal graphite has an interlayer distance of 0.34 nm in single-layer graphene, and this The graphene used in the energy storage device according to one aspect of the invention has a longer interlayer distance, therefore it is multilayer This facilitates the movement of carrier ions between the layers of graphene.

[0090] Graphene is chemically stable and has good electrical properties. Conductivity in graphene The high properties are due to the fact that the six-membered rings composed of carbon atoms are continuous in the planar direction. Graphene has high conductivity in the planar direction. Also, graphene is in sheet form. Therefore, in the stacked graphene, there is a gap in a direction parallel to the plane, and in that region While ion movement is possible, ion movement in directions perpendicular to the graphene plane is problematic. It is difficult.

[0091] The particle size of the positive electrode active material 503 is preferably 20 nm or more and 100 nm or less. Since electrons move within 503, it is preferable that the particle size of the positive electrode active material 503 be smaller.

[0092] Furthermore, sufficient properties can be obtained even if the surface of the positive electrode active material 503 is not coated with a graphite layer. However, if a positive electrode active material coated with a graphite layer and graphene are used together, This is more preferable because the carrier hops between the positive electrode active materials, allowing current to flow.

[0093] Figure 5(C) is a cross-sectional view of a portion of the positive electrode mixture layer 502 in Figure 5(B). Positive electrode active material It has 503 and graphene 504 covering the positive electrode active material 503. The graphene 504 is In the cross-sectional view, it is observed as a linear pattern. Multiple positive electrode active materials are made of the same graphene or multiple graphenes. It is placed so as to be sandwiched between the graphene layers. Note that the graphene is in the form of a bag. It may contain multiple positive electrode active materials. Also, it may not be covered by graphene, and some parts may be. The positive electrode active material may be exposed.

[0094] The thickness of the positive electrode mixture layer 502 is selected from a desired thickness between 20 μm and 100 μm. Furthermore, the thickness of the positive electrode mixture layer 502 may be adjusted as appropriate to prevent cracking or delamination. preferable.

[0095] Furthermore, the positive electrode mixture layer 502 contains acetylene in an amount between 0.1 and 10 times the volume of graphene. Carbon particles such as rack particles and carbon nanofibers with one-dimensional extension, public It may contain a conductive additive for knowledge.

[0096] In the positive electrode active material 503, the volume expands due to the intercalation of carrier ions. Therefore, charging and discharging causes the positive electrode mixture layer to become brittle, and a portion of the positive electrode mixture layer collapses. However, this results in a decrease in the reliability of the energy storage device. However, the positive electrode active material undergoes charging and discharging. Even if the volume increases or decreases, graphene surrounds the area, so graphene helps to disperse the positive electrode active material. It is possible to prevent the collapse of the positive electrode mixture layer. In other words, graphene, with charge and discharge It has the function of maintaining the bonding between positive electrode active materials even if the volume of the positive electrode active material increases or decreases.

[0097] Furthermore, graphene 504 is in contact with multiple positive electrode active materials 503 and also functions as a conductive additive. It is capable of holding a positive electrode active material 503 that can intercept and deintercept carrier ions. Therefore, there is no need to mix a binder into the positive electrode mixture layer, and the positive electrode per positive electrode mixture layer This makes it possible to increase the amount of active material, thereby increasing the charge and discharge capacity of the energy storage device.

[0098] Next, the manufacturing method for the positive electrode mixture layer 502 will be described.

[0099] A slurry containing particulate positive electrode active material and graphene oxide is formed. Next, the positive electrode current collector 5 The slurry is applied to both sides of 01. Then, a reduction treatment is performed by heating in a reducing atmosphere. This process involves firing the positive electrode active material and removing the oxygen contained in the graphene oxide. It forms gaps in the graphene. However, not all of the oxygen contained in graphene oxide is removed. The oxygen in the graphene remains.

[0100] Through the above process, a positive electrode mixture layer 502 of a predetermined shape is formed on the positive electrode current collector 501. This can be achieved. As a result, the conductivity of the positive electrode mixture layer is increased. Because graphene oxide contains oxygen, In polar solvents, it becomes negatively charged. As a result, graphene oxide particles disperse from one another. Therefore, The positive electrode active material contained in the slurry becomes less prone to aggregation, and the particle size of the positive electrode active material increases due to firing. This can reduce the amount of electrons that move within the positive electrode active material, thus facilitating the movement of electrons within the positive electrode mixture. The conductivity of the layer can be improved.

[0101] After forming a positive electrode mixture layer 502 on the positive electrode current collector 501, it is rolled using a roll press machine. Positive electrode 500 is manufactured.

[0102] (Negative electrode and method for manufacturing the same) Next, the negative electrode and its manufacturing method will be explained using Figure 6(A).

[0103] As shown in Figure 6(A), the negative electrode 510 consists of a negative electrode current collector 511 and both sides of the negative electrode current collector 511. It has a negative electrode mixture layer 512 provided on top of it.

[0104] The negative electrode current collector 511 is made of a highly conductive material such as metal. For example, stainless steel, iron, aluminum, copper, nickel, or titanium can be used as the material. It is possible. Also, the negative electrode current collector 511 can be foil-shaped, plate-shaped (sheet-shaped), mesh-shaped, or perforated. Shapes such as metal-like or expanded metal-like can be used as appropriate.

[0105] The negative electrode mixture layer 512 is provided on both sides of the negative electrode current collector 511. The negative electrode mixture layer 512 contains A negative electrode active material capable of intercalating and deintercalating ions, which act as carriers, is used.

[0106] The negative electrode active material undergoes a charge-discharge reaction through alloying and dealloying reactions with lithium metal. Alloy materials that allow for this can also be used. For example, Al, Si, Ge, Sn, Pb, S Examples of materials include those containing at least one of the following: b, Bi, Ag, Zn, Cd, In, Ga, etc. Such elements have a large capacity compared to carbon, and silicon in particular has a theoretical capacity of 4200 ml. Ah / g is dramatically high. Therefore, it is preferable to use silicon as the negative electrode active material. Examples of alloy materials using elements such as SiO, Mg2Si, Mg2Ge, SnO, SnO2, Mg2Sn, SnS2, V2Sn3, FeSn2, CoSn2, Ni 3Sn2, Cu6Sn5, Ag3Sn, Ag3Sb, Ni2MnSb, CeSb3, La Examples include Sn3, La3Co2Sn7, CoSb3, InSb, and SbSn.

[0107] In addition, as the negative electrode active material, oxides such as titanium dioxide (TiO2), lithium titanate (Li4T i5O 12 ), lithium-graphite intercalation compound (Li x C6), niobium pentoxide (Nb2O5) , tungsten oxide (WO2), molybdenum oxide (MoO2), etc. can be used. It is possible.

[0108] In addition, as the negative electrode active material, Li3N-type structured Li 3-x M x N (M = Co, Ni, Cu), which is a complex nitride of lithium and transition metal, can be used. For example, Li 2.6 Co 0.4 N3 shows a large charge-discharge capacity (900 mAh / g) and is preferable.

[0109] When using a complex nitride of lithium and transition metal, since lithium ions are contained in the negative electrode active material, it can be combined with materials such as V2O5 and Cr3O8 that do not contain lithium ions as the positive electrode active material and is preferable. Even when using a material containing lithium ions for the positive electrode active material , a complex nitride of lithium and transition metal can be used by previously desorbing lithium ions. It is possible.

[0110] When the negative electrode active material is silicon, amorphous silicon, microcrystalline silicon , polycrystalline silicon or a combination thereof can be used. Generally, the higher the crystallinity of silicon, the higher the electrical conductivity of silicon. Therefore, it can be used in a battery as an electrode with high conductivity. On the other hand, when silicon is amorphous, it can occlude carrier ions such as lithium compared to crystalline silicon and thus can increase the discharge capacity.

[0111] In this embodiment, a conductive assistant and a binder may be added to the above-described negative electrode active material, followed by pulverization, mixing, and firing to produce the negative electrode mixture layer 512, which may be used.

[0112] Also, as another example of the method for manufacturing the negative electrode 510, in the negative electrode 510 as well, similar to the positive electrode 500 graphene can be introduced into the negative electrode mixture layer 512. Thereby, it also has a function of maintaining the bonding between the negative electrode active materials even against the expansion and contraction of the negative electrode active material accompanying charge and discharge. Also at the same time, graphene also functions as a conductive assistant.

[0113] When using graphite as the negative electrode active material, for example, NMP (N-methylpyrrolidone) in which a vinylidene fluoride-based polymer such as polyvinylidene fluoride is dissolved in graphite powder is used as a binder and mixed to form a slurry. Next, the slurry is applied to one or both surfaces of the negative electrode current collector 511 and dried. When the coating process is performed only on one surface of the negative electrode current collector 511, on the other surface, the negative electrode mixture layer is formed again in the same manner. After this, rolling processing is performed using a roll press machine to manufacture the negative electrode 510.

[0114] On the other hand, when using silicon as the negative electrode active material, about four times the expansion due to the occlusion of carrier ions occurs, so simply forming a thin film on the negative electrode current collector 511 easily induces the peeling of the negative electrode mixture layer [[ID=^{31}]] . Therefore, it is necessary to use a shape of silicon other than a thin film shape such as particulate, whisker-like, or nanowire-like .

[0115] Examples of using particulate and whisker-like negative electrode active materials as the negative electrode active material will be described below with reference to FIGS. 6(A) to (D ).

[0116] ​​​​Figure 6(A) is a cross-sectional view of the negative electrode 510. The negative electrode is formed by a negative electrode mixture on both sides of the negative electrode current collector 511. Layer 512 is formed. Note that the negative electrode mixture layer 512 contains at least the negative electrode active material. In addition, it may also contain a binder, a conductive additive, and graphene.

[0117] Figure 6(B) is a plan view of a portion of the negative electrode mixture layer 512. The negative electrode mixture layer 512 is composed of particles The negative electrode active material 513 is in the shape of a negative electrode active material 513, and the negative electrode active material 513 is covered by multiple negative electrode active materials 513 inside It is composed of graphene 514 packed inside. The negative electrode mixture layer 512 in plan view is composed of multiple The surface of the negative electrode active material 513 is covered with different graphene 514. Note that in some cases, The negative electrode active material 513 may be exposed.

[0118] Figure 6(C) is a cross-sectional view of a portion of the negative electrode mixture layer 512 in Figure 6(B). Negative electrode active material 513 and the graph covering the negative electrode active material 513 in a plan view of the negative electrode mixture layer 512 Graphene 514 is shown in the diagram. In the cross-sectional view, graphene 514 is observed as a linear material. One or more graphenes are superimposed on multiple negative electrode active materials 513, or the same The negative electrode active material 513 is contained within one or more graphenes. Graphene 514 is shaped like a bag, and inside it contains multiple negative electrode active materials. In some cases, graphene 514 has some open areas, and in those areas, the negative electrode activity Substance 513 may be exposed.

[0119] The thickness of the negative electrode mixture layer 512 is selected from a desired thickness between 20 μm and 100 μm.

[0120] Furthermore, the negative electrode mixture layer 512 contains acetylene in an amount between 0.1 and 10 times the volume of graphene. It may have any known conductive assistant such as black particles and carbon particles having a one-dimensional spread (such as carbon nanofibers), and any known binder such as polyvinylidene fluoride. It may have any known conductive assistant, and any known binder such as polyvinylidene fluoride.

[0121] Note that the negative electrode mixture layer 512 may be pre-doped with lithium. As a method for pre-doping lithium, a lithium layer may be formed on the surface of the negative electrode mixture layer 512 by sputtering. Alternatively, by providing a lithium foil on the surface of the negative electrode mixture layer 512, the negative electrode mixture layer 512 can be pre-doped with lithium. In particular, when graphene 504 is generated in the positive electrode mixture layer 502 of the positive electrode 500 after assembling the lithium secondary battery, it is preferable to pre-dope the negative electrode mixture layer 512 with lithium. That is, when the lithium secondary battery is assembled and then graphene 504 is generated in the positive electrode mixture layer 502 of the positive electrode 500, it is preferable to pre-dope the negative electrode mixture layer 512 with lithium. In addition, among the negative electrode active materials 513, there are those whose volume expands due to the occlusion of carrier ions. Therefore, due to charge and discharge, the negative electrode mixture layer becomes brittle, and a part of the negative electrode mixture layer collapses, thereby reducing the reliability (such as cycle characteristics, etc.) of the lithium secondary battery. However, in the negative electrode of the lithium secondary battery according to one aspect of the present invention, since the graphene 514 covers the periphery of the negative electrode active material 513, even if the volume of the negative electrode active material 513 increases or decreases due to charge and discharge, the graphene 514 can prevent the pulverization of the negative electrode active material 513 and the collapse of the negative electrode mixture layer 512. That is, the graphene 514 contained in the negative electrode of the lithium secondary battery according to one aspect of the present invention has a function of maintaining the binding between the negative electrode active materials 513 even when the volume of the negative electrode active material 513 expands and contracts during charge and discharge. Therefore, by using the negative electrode 510, the durability of the power storage element can be improved.

[0122] Note that among the negative electrode active materials 513, there are those whose volume expands due to the occlusion of carrier ions. Therefore, due to charge and discharge, the negative electrode mixture layer becomes brittle, and a part of the negative electrode mixture layer collapses, resulting in a decrease in the reliability (such as cycle characteristics, etc.) of the lithium secondary battery. However, in the negative electrode of the lithium secondary battery according to one aspect of the present invention, since the graphene 514 covers the periphery of the negative electrode active material 513, even if the volume of the negative electrode active material 513 increases or decreases due to charge and discharge, the graphene 514 can prevent the pulverization of the negative electrode active material 513 and the collapse of the negative electrode mixture layer 512. That is, the graphene 514 contained in the negative electrode of the lithium secondary battery according to one aspect of the present invention has a function of maintaining the binding between the negative electrode active materials 513 even when the volume of the negative electrode active material 513 expands and contracts during charge and discharge. Therefore, by using the negative electrode 510, the durability of the power storage element can be improved. That is, the graphene 514 contained in the negative electrode of the lithium secondary battery according to one aspect of the present invention has a function of maintaining the binding between the negative electrode active materials 513 even when the volume of the negative electrode active material 513 expands and contracts during charge and discharge. Therefore, by using the negative electrode 510, the durability of the power storage element can be improved. Therefore, the durability of the power storage element can be improved.

[0123] In other words, there is no need to use a binder when forming the negative electrode mixture layer 512, and a constant weight (constant In the negative electrode mixture layer (by volume), it is possible to increase the amount of negative electrode active material. Therefore, This allows for an increase in charge / discharge capacity per unit electrode weight (electrode volume).

[0124] Furthermore, graphene 514 is conductive and is in contact with multiple negative electrode active materials 513. Therefore, it also functions as a conductive additive. In other words, when forming the negative electrode mixture layer 512, the conductive additive is used. It does not need to be used, and in a negative electrode mixture layer of a fixed weight (fixed volume), the amount of negative electrode active material is increased. This makes it possible to increase the charge / discharge capacity per unit electrode weight (electrode volume). It is possible.

[0125] Furthermore, graphene 514 efficiently and sufficiently provides a conductive path (carrier) to the negative electrode mixture layer 512. Because an ion conductive path is formed, the conductivity of the negative electrode mixture layer 512 and the negative electrode 510 are It has excellent conductivity. Therefore, the energy storage element having the negative electrode 510 has a capacity of the negative electrode active material 513. Because it can be used efficiently to the same extent as the theoretical capacity, the charge and discharge capacity can be sufficiently increased. can.

[0126] Furthermore, graphene 514 also functions as a negative electrode active material capable of intercalating and deintercalating carrier ions. Therefore, the charge and discharge capacity of the negative electrode 510 can be improved.

[0127] Next, the method for producing the negative electrode mixture layer 512 shown in Figures 6(B) and (C) will be described.

[0128] A slurry containing particulate negative electrode active material 513 and graphene oxide is formed. Specifically, A slurry is formed by kneading a dispersion containing particulate negative electrode active material 513 and graphene oxide. To form.

[0129] Next, the slurry is applied to the negative electrode current collector 511. Then, vacuum drying is performed for a certain period of time. Then the solvent is removed from the slurry coated onto the negative electrode current collector 511. After this, roll press The process involves rolling using a machine.

[0130] Subsequently, electrochemical reduction of graphene oxide using electrical energy, and heat treatment... Graphene 514 is produced by the thermal reduction of graphene oxide. The negative electrode mixture layer 512 can be formed on both sides of the negative electrode current collector 511, thereby manufacturing the negative electrode 510. It is possible.

[0131] Next, we will explain the structure of the negative electrode shown in Figure 6(D).

[0132] Figure 6(D) is a cross-sectional view of the negative electrode where the negative electrode mixture layer 517 is formed on the negative electrode current collector 511. The negative electrode mixture layer 517 consists of a negative electrode active material 515 with an uneven surface and the surface of the negative electrode active material 515 It has graphene 516 covering it.

[0133] The uneven negative electrode active material 515 has a common portion 515a and a protruding portion 51 that extends from the common portion 515a. It has 5b. The protrusion 515b is a columnar, prismatic, conical, or pyramidal needle shape. The shape may be as appropriate. The top of the convex part may be curved. Also, the negative electrode active material 51 5 uses a negative electrode active material capable of intercalating and deintercalating carrier ions (typically lithium ions). It is formed by the same material. Alternatively, the common part 515a and the protruding part 515b may be made of different materials. stomach.

[0134] The negative electrode shown in Figure 6(D) uses silicon as the negative electrode active material 515, and graphene 5 Because the negative electrode active material 515 is surrounded by 16, the negative electrode active material 515 is affected during charging and discharging. Therefore, even if the volume increases or decreases, it prevents the pulverization of the negative electrode active material 515 and the collapse of the negative electrode mixture layer 517. It is possible.

[0135] Furthermore, when the surface of the negative electrode mixture layer comes into contact with the electrolyte that constitutes the energy storage device, the electrolyte and The negative electrode active material reacts with the negative electrode, forming a film on the surface of the negative electrode. This film is formed by the reaction between the negative electrode and the electrolyte. It is thought to be necessary to alleviate and stabilize the effect. However, the coating As the thickness increases, carrier ions become less likely to be absorbed into the negative electrode, and carrier ions between the electrode and the electrolyte... Problems include reduced on-conductivity and electrolyte depletion.

[0136] By coating the surface of the negative electrode active material 515 with graphene 516, the thickness of the coating can be increased. This can be suppressed, and the decrease in charge / discharge capacity can be prevented.

[0137] In addition, as another configuration of the uneven negative electrode active material 515, the negative electrode current collector 511 is connected to the negative electrode current collector 51 By covering the protrusions formed as part of 1 with a thin film of negative electrode active material, the uneven surface is created It can also be a negative electrode active material. In this configuration, it comes from a part of the negative electrode current collector 511. The protruding portion functions as the core of the thin film-like negative electrode active material, thereby increasing the strength of the negative electrode active material. This is possible, especially in silicon fields where the negative electrode active material exhibits significant expansion and contraction associated with the intercalation and deintercalation of carrier ions. It is useful in combination.

[0138] Next, the method for preparing the negative electrode mixture layer 517 shown in Figure 6(D) will be explained.

[0139] The surface of the negative electrode active material 515 is modified by printing, inkjet, CVD, etc. It is applied to both sides of 11. Alternatively, a film-like negative coating is applied by coating, sputtering, vapor deposition, etc. After providing the electrode active material, it is selectively removed, and the uneven negative electrode active material 515 is placed on the negative electrode current collector 51 1. Provide on both sides of the surface.

[0140] Next, a dispersion containing graphene oxide is coated onto the uneven negative electrode active material 515. For coating with a dispersion containing rafen, the previously described method may be used as appropriate.

[0141] Next, after removing the solvent from the dispersion containing graphene oxide, electrical energy is used to... Alternatively, graphene 516 can be produced by chemically reducing graphene oxide using gaseous energy. Graphene 516 may be produced by thermally reducing graphene oxide using energy. .

[0142] In this way, graphene is produced using a dispersion containing graphene oxide, resulting in a textured surface. The surface of the negative electrode active material 515 can be coated with graphene 516 of a uniform thickness.

[0143] Furthermore, the negative electrode is produced by the LPCVD method using silane, silane chloride, silane fluoride, etc. as raw material gases. On the current collector 511, there is a negative electrode active material 515 (hereinafter referred to as silicon) with an uneven surface, formed of silicon. It can be installed (called a whisker).

[0144] Silicon whiskers may have an amorphous structure. Amorphous silicon whiskers are combined with the negative electrode. By using it in the formulation layer 517, it is resistant to volume changes associated with the absorption and release of carrier ions (for example) Therefore, to relieve the stress associated with volume expansion, repeated charging and discharging of silicon wisps This prevents the pulverization of the ka and the collapse of the negative electrode mixture layer 517, further improving the cycle characteristics of the storage It is possible to manufacture electrical devices.

[0145] Alternatively, the silicon whisker may have a crystalline structure. In this case, conductivity and carrier ions The crystal structure, which has excellent crystalline properties for mobility, is in wide contact with the current collector. Therefore, negative The overall conductivity of the electrode can be further improved, enabling even faster charging and discharging. It is possible to manufacture energy storage devices with even greater capacity.

[0146] Alternatively, a silicon whisker has a core which is a crystalline region, and is provided covering the core. It may have an outer shell which is an amorphous region.

[0147] The amorphous structure of the outer shell is resistant to volume changes associated with the intercalation and release of carrier ions (for example) It has the characteristic of relieving stress associated with volume expansion. It also has a crystalline core. The structure exhibits excellent conductivity and carrier ion mobility, and rapidly absorbs carrier ions. It has the characteristic of having a high rate of release per unit mass. Therefore, the core and outer shell By using silicon whiskers as the negative electrode mixture layer 517, high-speed charging and discharging is possible. This makes it possible to manufacture energy storage devices with improved charge / discharge capacity and cycle characteristics.

[0148] (Energy storage element and method for manufacturing the same) The strip-shaped positive electrode 500 and negative electrode 510 manufactured as described above are then cut to a predetermined size. Prepare multiple units of each type, connecting the positive electrode 500 to the positive electrode tab and the negative electrode 510 to the negative electrode tab. Electrodes The connection between the electrode and the tab is specifically the connection between the current collector of the electrode and the tab. Electrical connections are made along with physical structural fixation. Positive electrode and positive electrode tab, and negative electrode and negative electrode tab. For fixing it to the bracket, for example, ultrasonic welding can be used.

[0149] Next, between the multiple positive electrodes 500 and multiple negative electrodes 510 bundled together by tabs, a continuous one Multiple sheet-like separators are placed between each positive and negative electrode. The meter uses an insulating porous material, but the coefficient of sliding friction between the positive and negative electrode surfaces is low. A non-adhesive insulating material is preferable, such as polypropylene or polytetrafluoroethylene. n is preferable.

[0150] This embodiment can be implemented in appropriate combination with other embodiments.

[0151] (Embodiment 5) An energy storage device according to one aspect of the present invention can be used as a power source for various electrical devices. In this context, electrical equipment refers to all industrial products that include parts that operate using electrical power. This is not limited to consumer products such as home appliances, but also broadly applies to various uses such as commercial, industrial, and military applications. It falls into that category.

[0152] As a specific example of an electrical device using a power storage device according to one aspect of the present invention, a television, monitor, etc. Display devices, lighting devices, desktop or notebook personal computers, Word documents Processors, recording media such as DVDs (Digital Versatile Discs) Image playback device that plays still images or videos stored in a device, portable CD player, radio Tape recorder, headphone stereo, stereo, desk clock, wall clock, cordless Cordless telephone handsets, transceivers, portable radios, mobile phones, car phones, portable game consoles, toys, Calculators, personal digital assistants, electronic organizers, e-books, electronic translators, voice input devices, video cameras, Digital still cameras, electric shavers, high-frequency heating devices such as microwave ovens, electric rice cookers, electric Washing machine, electric vacuum cleaner, water heater, electric fan, hair dryer, air conditioner, humidifier, dehumidifier Humidifiers and other air conditioning equipment, dishwashers, dish dryers, clothes dryers, futon dryers, electric refrigerators, Electric freezers, electric refrigerators / freezers, DNA storage freezers, flashlights, power tools, smoke detectors, transparent Examples include medical equipment such as analytical devices. Furthermore, guide lights, traffic lights, belt conveyors, elevators, etc. Beta, escalators, industrial robots, power storage systems, power leveling and smart Industrial equipment such as energy storage devices for the lid can also be used. Mobile devices propelled by electric motors are also included in the category of electrical equipment. For example, electric vehicles (EVs), hybrid vehicles that combine internal combustion engines and electric motors ( HEVs, plug-in hybrid vehicles (PHEVs), change their wheels to tracks. Tracked vehicles, motorized bicycles including electric assist bicycles, motorcycles, electric wheelchairs, etc. Carts for use with rockets, small or large vessels, submarines, helicopters, aircraft, rockets, and satellites. Examples include space probes, planetary probes, and spacecraft.

[0153] Furthermore, the above electrical equipment is used as a main power source to supply almost all of its power consumption, according to one aspect of the present invention. A power storage device related to the above can be used. Alternatively, the above electrical equipment can be powered by the main power supply or commercial power supply. Uninterruptible power supply to electrical equipment in the event of a power outage from the power source. As a power source, a power storage device according to one aspect of the present invention can be used. Alternatively, the above power In parallel with the supply of power to electrical equipment from the main power supply or commercial power supply, the electrical equipment... A power storage device according to one aspect of the present invention is used as an auxiliary power source for supplying electricity. It is possible.

[0154] Figure 7 shows the specific configuration of the above electrical equipment. In Figure 7, the display device 8000 is the main power This is an example of an electrical device using a power storage device 8004 according to one embodiment of the present invention. Specifically, a display device The 8000 corresponds to a display device for receiving TV broadcasts, and consists of a housing 8001, a display unit 8002, and a speaker. It has a ker section 8003, a power storage device 8004, etc. Power storage device 8004 according to one aspect of the present invention It is located inside the enclosure 8001. The display device 8000 receives power from the commercial power supply. It can receive power from the device, or it can use the power stored in the energy storage device 8004. Therefore, even when power cannot be supplied from the commercial power source due to a power outage, one aspect of the present invention By using the energy storage device 8004 as an uninterruptible power supply, the display device 8000 can be used. It becomes Noh.

[0155] The display unit 8002 has light-emitting elements such as liquid crystal display devices and organic EL elements in each pixel. Equipment, electrophoresis display device, DMD (Digital Micromirror Display) ce), PDP (Plasma Display Panel), FED (Field Semiconductor display devices such as Emission Displays can be used.

[0156] In addition to being used for receiving TV broadcasts, display devices are also used for personal computers, advertising displays, and more. , including all information display devices. In particular, the energy storage device according to one aspect of the present invention is thin and Furthermore, by utilizing its flexibility, a thin and curved information display device is used. It can be applied.

[0157] In Figure 7, the fixed lighting device 8100 is a power storage device 810 according to one aspect of the present invention. This is an example of an electrical device using 3. Specifically, the lighting device 8100 consists of a housing 8101 and a light source. It has components 8102, a power storage device 8103, etc. In Figure 7, the power storage device 8103 is located on the housing 8101. And, as an example, the case in which the light source 8102 is installed inside the ceiling 8104. However, the energy storage device 8103 may be located inside the housing 8101. In particular, lighting If the device 8100 is a thin type with a curved shape, then the energy storage device according to one aspect of the present invention It is optimally suited for use. The lighting device 8100 can also receive power from the commercial power supply. Furthermore, the power stored in the energy storage device 8103 can also be used. Therefore, in the event of a power outage, Even when power cannot be supplied from the commercial power source, the energy storage device 8103 according to one aspect of the present invention By using this as an uninterruptible power supply, the lighting device 8100 can be used.

[0158] Figure 7 illustrates a fixed lighting fixture 8100 installed on the ceiling 8104. However, in one aspect of the present invention, the energy storage device has a ceiling 8104, for example, a side wall 8105, a floor 81 06. It can also be used in fixed lighting devices installed in windows 8107, etc., or as a tabletop type. It can also be used in lighting devices, etc.

[0159] Furthermore, the light source 8102 can be an artificial light source that uses electricity to artificially produce light. Specifically, this includes incandescent light bulbs, discharge lamps such as fluorescent lamps, and light-emitting elements such as LEDs and organic EL elements. The element is an example of the artificial light source mentioned above.

[0160] In Figure 7, the air conditioner having an indoor unit 8200 and an outdoor unit 8204 is the present This is an example of an electrical device using a power storage device 8203 according to one embodiment of the present invention. Specifically, the indoor unit 8 Unit 200 has a housing 8201, an air outlet 8202, a power storage device 8203, etc. In Figure 7, the storage The example shows the case where the electrical device 8203 is installed in the indoor unit 8200, but the energy storage device 8 203 may be located on the outdoor unit 8204. Alternatively, the indoor unit 8200 and the outdoor unit 8 Both 204 may be equipped with energy storage devices 8203. The air conditioner is commercial It can receive power from a power source, or it can use the power stored in the energy storage device 8203. It is also possible that the energy storage device 8203 is connected to both the indoor unit 8200 and the outdoor unit 8204. If provided, this will continue to operate even when power cannot be supplied from the commercial power source due to a power outage or other reasons. By using the energy storage device 8203 according to one aspect of the invention as an uninterruptible power supply, the air conditioner Yona will become available for use.

[0161] Figure 7 illustrates a separate-type air conditioner consisting of an indoor unit and an outdoor unit. However, there are integrated air conditioners that have both the indoor and outdoor unit functions in a single housing. A power storage device according to one aspect of the present invention can also be used in the Shona.

[0162] In Figure 7, the electric refrigerator 8300 uses a power storage device 8304 according to one aspect of the present invention. This is an example of an electrical appliance. Specifically, the electric refrigerator 8300 has a casing 8301, and a refrigerator It has a room door 8302, a freezer door 8303, an energy storage device 8304, etc. Figure 7 shows the energy storage device The unit 8304 is located inside the enclosure 8301. The electric refrigerator 8300 is a commercial It can receive power from a power source, or it can use the power stored in the energy storage device 8304. It is also possible to do so. Therefore, even when power cannot be supplied from the commercial power source due to a power outage, By using the energy storage device 8304 according to one aspect of the present invention as an uninterruptible power supply, electric refrigeration and cooling Warehouse 8300 will become available for use.

[0163] Of the electrical appliances mentioned above, high-frequency heating devices such as microwave ovens and electric rice cookers are included. The equipment requires high power in a short period of time. Therefore, it needs to supplement the power that cannot be supplied by the commercial power supply. As an auxiliary power source for this purpose, by using the energy storage device according to one aspect of the present invention, the electrical equipment This prevents the commercial power circuit breaker from tripping during use.

[0164] Furthermore, during periods when electrical equipment is not in use, especially the total amount of electricity that the commercial power source can supply... During periods when the proportion of electricity actually used (called the electricity usage rate) is low, energy storage is used. By storing power in the device, the increase in power usage outside of the above-mentioned time period is suppressed. It is possible. For example, in the case of the electric refrigerator 8300, when the temperature is low, the refrigerator door 830 2. At night when the freezer door 8303 is not opened or closed, power is stored in the energy storage device 8304. And as the temperature rises, the refrigerator door 8302 and the freezer door 8303 are opened and closed. During the daytime, by using the energy storage device 8304 as an auxiliary power source, the daytime power usage rate It can be kept low.

[0165] This embodiment can be implemented in appropriate combination with other embodiments.

[0166] (Embodiment 6) In this embodiment, an electrical device having a curved shape to which an energy storage device according to one aspect of the present invention is applied An example will be explained using Figure 8.

[0167] Figure 8(A) shows an example of a mobile phone. The mobile phone 8500 is housed in the casing 8501. In addition to the built-in display unit 8502, there are operation buttons 8503, an external connection port 8504, and a speaker. It is equipped with the 8505 microphone, 8506 microphone, etc. Also, inside the mobile phone 8500 A power storage device according to one aspect of the present invention is installed.

[0168] The mobile phone 8500 shown in Figure 8(A) allows information to be accessed by touching the display unit 8502 with a finger or the like. You can input text. You can also make phone calls or type text. The operation can be performed by touching the display unit 8502 with a finger or other object.

[0169] Furthermore, by operating the control button 8503, the power can be turned ON or OFF, and the display unit 8502 will show... You can switch the type of image displayed. For example, from the email composition screen, the main menu - You can switch to a different screen.

[0170] Here, the mobile phone 8500 incorporates a flexible energy storage device according to one aspect of the present invention. In Figure 8(A), the mobile phone 8500 is designed to be convex upwards in the lateral direction. It is curved in an arc shape. Therefore, the power storage device of one aspect of the present invention is located next to the mobile phone 8500. They should be arranged to allow for flexibility in the direction. In this way, they have a curved shape. Furthermore, it can be made into a thin mobile phone.

[0171] Figure 8(B) shows an example of a wristband-type display device. The portable display device 8600 is It comprises a housing 8601, a display unit 8602, operation buttons 8603, and a transmitting / receiving device 8604. Furthermore, the portable display device 8600 is equipped with a power storage device according to one aspect of the present invention. ru.

[0172] The portable display device 8600 is capable of receiving video signals by the transceiver 8604, and the received The video can be displayed on the display unit 8602. Additionally, the audio signal can be transmitted to other receiving devices. It is also possible to do so.

[0173] Additionally, the 8603 control button allows you to turn the power on and off and switch the displayed image. You can also adjust the volume of the sound, etc.

[0174] Here, the portable display device 8600 incorporates a flexible energy storage device according to one aspect of the present invention. In Figure 8(B), the portable display device 8600 is convex upwards in the vertical direction. It is curved in an arc shape. Therefore, one aspect of the present invention is a power storage device, and the portable display device 860 It should be arranged so that it is flexible in the vertical direction of 0. Therefore, it has a curved surface. Furthermore, it can be made into a thin, portable display device.

[0175] Furthermore, the present invention is not limited to the electrical equipment described above, as long as it is equipped with a power storage device according to one embodiment of the present invention. Needless to say, that's not possible.

[0176] This embodiment can be implemented in appropriate combination with other embodiments. [Explanation of Symbols]

[0177] 100 energy storage elements 101 Positive electrode 102 Separator 103 Negative electrode 104 Positive Tab 105 Negative Electrode Tab 200 Energy Storage Elements 201 Positive electrode 202 Separator 203 Negative electrode 204 Positive Tab 205 Negative Electrode Tab 400 Energy storage devices 401 Exterior 401a Insulating synthetic resin film 401b Metal thin film 401c insulating film 402 Positive Tab 402a Positive Tab 402b Negative Tab 403 Positive Tab 404 Energy Storage Element 405 Electrolyte 406 Support plate 407 Wiring 500 positive electrode 501 Positive electrode current collector 502 Cathode mixture layer 503 Cathode active material 504 Graphene 510 negative electrode 511 Negative electrode current collector 512 Negative electrode mixture layer 513 Negative electrode active material 514 Graphene 515 Negative electrode active material 515a Common area 515b protrusion 516 Graphene 517 Negative electrode mixture layer 8000 display device 8001 enclosure 8002 Display section 8003 Speaker section 8004 Energy Storage Device 8100 Lighting device 8101 enclosure 8102 Light source 8103 Energy storage device 8104 Ceiling 8105 Side wall 8106 floor 8107 Window 8200 indoor unit 8201 enclosure 8202 Air outlet 8203 Energy Storage Device 8204 Outdoor unit 8300 Electric Refrigerator / Freezer 8301 enclosure 8302 Refrigerator door 8303 Freezer door 8304 Energy storage device 8500 mobile phones 8501 enclosure 8502 Display section 8503 Operation Buttons 8504 External connection port 8505 Speaker 8506 Microphone 8600 Portable Display Devices 8601 enclosure 8602 Display section 8603 Operation Buttons 8604 Transceiver

Claims

1. An energy storage device comprising an energy storage element, an electrolyte, a positive electrode tab, a negative electrode tab, a support plate, and an outer casing, The aforementioned energy storage element is a laminate in which the positive electrode and negative electrode are alternately stacked with a separator in between. The positive electrode tab comprises a first positive electrode tab and a second positive electrode tab. The negative electrode tab comprises a first negative electrode tab and a second negative electrode tab. The positive electrode is electrically connected to the second positive electrode tab via the first positive electrode tab. The first positive electrode tab and the first negative electrode tab are physically connected to the support plate, The second positive electrode tab and the second negative electrode tab each have a region that contacts the electrolyte, a region that does not contact the electrolyte, and a region that contacts the outer casing. The support plate is a flexible energy storage device.

2. In claim 1, The support plate comprises a metal core and an insulating material covering the metal core, wherein the device is an energy storage device.

Images