Current collector, electrode, battery, flying object, method for producing a current collector, method for producing an electrode, and method for producing a battery

Abstract

To provide a current collector enabling increase of energy density per unit mass of a power storage cell.SOLUTION: The current collector comprises: a support layer 420 including resin material; and electrically conductive layers 542, 544 formed on least one surface of the support layer and having electric conductivity higher than that of the support layer. In the electrically conductive layer, there are formed exposing portion 450 and 550 which penetrate through the electrically conductive layer and expose a part of the support layer without penetrating through the support layer. The electrically conductive layers may have a main body portion 562 and an extending portion 564 extending from a part of the main body portion to the outside of the main body portion. The exposing portion may be located near a boundary between the main body portion and the extending portion. At least a part of the exposing portion may be located inside the extending portion.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a current collector, an electrode, a battery, an aircraft, a method of producing a current collector, a method of producing an electrode, and a method of producing a battery. [Background technology]

[0002] Patent Document 1 describes an electrochemical cell that includes a first current collector bonded to a first portion of a pouch and having a first electrode material disposed thereon, a second current collector bonded to a second portion of the pouch and having a second electrode material disposed thereon, and a separator disposed between the first and second electrode materials. In the electrochemical cell described in Patent Document 1, the first portion of the pouch is bonded to the second portion of the pouch to enclose the electrochemical cell. [Prior art document] [Patent documents] [Patent Document 1] JP 2021-012891 A Summary of the Invention [Means for solving the problem]

[0003] In a first aspect of the present invention, a current collector is provided. The current collector includes, for example, a support layer including a resin material. The current collector includes, for example, a conductive layer formed on at least one surface of the support layer and having a higher conductivity than the support layer. In the current collector, for example, an exposed portion is formed in the conductive layer, which penetrates the conductive layer and exposes a part of the support layer without penetrating the support layer.

[0004] In any of the current collectors described above, the support layer may include a thermoplastic resin material. In any of the current collectors described above, the conductive layer may have a main body portion and an extension portion extending from a part of the main body portion toward the outside of the main body portion. The exposed portion may be disposed near a boundary between the main body portion and the extension portion. In any of the current collectors described above, at least a part of the exposed portion may be disposed inside the extension portion.

[0005] In any of the current collectors described above, the conductive layer may have a plurality of exposed portions. At least a portion of the plurality of exposed portions may be disposed on at least a portion of the periphery of the conductive layer. In any of the current collectors described above, the conductive layer may have a main body portion and an extension portion extending from a portion of the main body portion toward the outside of the main body portion. The main body portion may have a plurality of exposed portions formed therein.

[0006] In any of the current collectors described above, the conductive layer may have a first conductive layer formed on a first surface of the support layer and a second conductive layer formed on a second surface of the support layer. The current collector may have a through hole penetrating the first conductive layer, the support layer, and the second conductive layer.

[0007] In any of the current collectors described above, each of the first conductive layer and the second conductive layer may have a main body portion and an extension portion extending from a part of the main body portion toward the outside of the main body portion. The through hole may penetrate a part of the extension portion of the first conductive layer, a part of the support layer, and a part of the extension portion of the second conductive layer. Any of the current collectors described above may include a connection member disposed inside the through hole and electrically connecting the first conductive layer and the second conductive layer. In any of the current collectors described above, the conductive layer may have one or more exposed portions formed therein. The current collector may have one or more through holes formed therein. The average value of the circle equivalent diameter of the one or more exposed portions may be different from the average value of the circle equivalent diameter of the one or more exposed portions.

[0008] In a second aspect of the present invention, an electrode is provided. The electrode includes, for example, any of the current collectors according to the first aspect. The electrode includes, for example, an active material layer disposed on at least one surface of the current collector.

[0009] In a third aspect of the present invention, a battery is provided. The battery includes, for example, a positive electrode. The battery includes, for example, a negative electrode. The battery includes, for example, a separator disposed between the positive electrode and the negative electrode. In the battery, the positive electrode includes, for example, any of the current collectors according to the first aspect and a positive electrode active material layer disposed on at least one surface of the current collector. In the battery, the negative electrode includes, for example, any of the current collectors according to the first aspect and a negative electrode active material layer disposed on at least one surface of the current collector.

[0010] In a fourth aspect of the present invention, an aircraft is provided. The aircraft includes, for example, any of the batteries according to the third aspect. The aircraft includes, for example, a thrust generating device that generates thrust using the electrical energy stored in the battery.

[0011] In a fifth aspect of the present invention, a battery is provided. The battery includes, for example, a first electrode. The battery includes, for example, a second electrode. The battery includes, for example, a separator disposed between the first electrode and the second electrode. In the battery, the first electrode includes, for example, a first current collector. In the battery, the first electrode includes, for example, a first active material layer disposed on at least one surface of the first current collector. In the battery, the second electrode includes, for example, a second current collector. In the battery, the second electrode includes, for example, a second active material layer disposed on at least one surface of the second current collector. In the battery, each of the first current collector and the second current collector includes, for example, a support layer including a resin material. In the battery, each of the first current collector and the second current collector includes, for example, a conductive layer formed on at least one surface of the support layer and having a higher conductivity than the support layer. In the above battery, the resin material contained in at least a portion of the peripheral portion of the support layer of the first current collector and the resin material contained in at least a portion of the peripheral portion of the support layer of the second current collector are integrated together so as to seal the first active material layer, the separator, and the second active material layer by the first current collector and the second current collector.

[0012] Any of the above batteries may include a first terminal for electrically connecting an external device to the first current collector. In any of the above batteries, the first terminal may be electrically connected to the conductive layer of the first current collector outside a region where the resin material of the first current collector and the resin material of the second current collector are integrated.

[0013] Any of the above batteries may include a first terminal for electrically connecting an external device to the first current collector. In any of the above batteries, the first terminal may be electrically connected to the conductive layer of the first current collector inside a region where the resin material of the first current collector and the resin material of the second current collector are integrated.

[0014] In a sixth aspect of the present invention, an aircraft is provided. The aircraft includes, for example, any of the batteries according to the fifth aspect. The aircraft includes, for example, a thrust generating device that generates thrust by utilizing the electrical energy stored in the battery.

[0015] In a seventh aspect of the present invention, a method for producing a current collector is provided. The method includes, for example, a conductive layer forming step of forming a conductive layer including a conductive material having a higher conductivity than the resin material on at least one surface of a support layer including a resin material. In the method, the conductive layer forming step includes, for example, a disposing step of disposing a conductive material on at least one surface of the support layer so that the conductive material penetrates the conductive layer and forms a conductive layer having an exposed portion that exposes a part of the support layer without penetrating the support layer.

[0016] In an eighth aspect of the present invention, a method for producing an electrode is provided. The method includes, for example, a step of preparing a current collector. The method includes, for example, an active material layer forming step of forming an active material layer containing an active material on at least one surface of the current collector. In the method, the current collector includes, for example, a support layer containing a resin material. In the method, the current collector includes, for example, a conductive layer formed on at least one surface of the support layer and having better conductivity than the support layer. In the method, the conductive layer includes, for example, an exposed portion that penetrates the conductive layer and exposes a part of the support layer without penetrating the support layer. In the method, the conductive layer includes, for example, a main body member and an extension member that extends from a part of the main body member toward the outside of the main body member. In the method, the active material layer forming step includes, for example, a step of forming an active material layer on at least a part of the main body member of the conductive layer.

[0017] In a ninth aspect of the present invention, a method for producing a battery is provided. The method includes, for example, a lamination step of laminating a first electrode, a separator, and a second electrode in this order. The method includes, for example, an integration step of integrating at least a part of the periphery of the first electrode with at least a part of the periphery of the second electrode. In the method, the first electrode includes, for example, a first current collector. The first electrode includes, for example, a first active material layer disposed on at least one surface of the first current collector. In the method, the second electrode includes, for example, a second current collector. The second electrode includes, for example, a second active material layer disposed on at least one surface of the second current collector. In the method, each of the first current collector and the second current collector includes, for example, a support layer including a resin material. Each of the first current collector and the second current collector includes, for example, a conductive layer formed on at least one surface of the support layer and having a higher conductivity than the support layer. In the above method, the integration step includes, for example, a sealing step of integrating a resin material contained in at least a portion of the peripheral portion of the support layer of the first current collector with a resin material contained in at least a portion of the peripheral portion of the support layer of the second current collector to seal the first active material layer, the separator, and the second active material layer.

[0018] The above summary of the invention does not list all of the necessary features of the present invention. Also, subcombinations of these features may also be inventions. [Brief description of the drawings]

[0019] [Figure 1] 1 shows a schematic diagram of an example of the system configuration of an aircraft 100. [Diagram 2] 2 shows a schematic diagram of an example of the internal configuration of the power storage cell 112. [Diagram 3] An example of a cross section of a power storage cell 112 is shown diagrammatically. [Figure 4] An example of a current collector 400 is shown diagrammatically. [Diagram 5] An example of a cross section of a current collector 400 is shown diagrammatically. [Figure 6] Another example of a cross section of a current collector 400 is shown diagrammatically. [Figure 7] An example of the positional relationship of each part of the current collector 400 is shown roughly. [Figure 8] An example of the positional relationship between the current collector 400 and other members is shown roughly. [Figure 9] An example of a current collector 900 is shown diagrammatically. [Figure 10] An example of a current collector 1000 is shown diagrammatically. [Figure 11] An example of a method for producing a positive electrode 220 or a negative electrode 240 is shown generally. [Figure 12] An example of a method for producing a power storage cell 112 is shown generally. [Figure 13] An example of the top surface of the power storage cell 112 is shown diagrammatically. [Figure 14] An example of a cross section of a storage cell 1412 is shown diagrammatically. [Figure 15] An example of a cross section of a storage cell 1512 is shown diagrammatically. [Figure 16] An example of the top surface of the storage cell 1612 is shown diagrammatically. [Figure 17] An example of components that make up the storage cell 1612 is shown diagrammatically. [Figure 18]Another example of components that make up the storage cell 1612 is shown diagrammatically. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] According to one embodiment exemplified in this specification (sometimes referred to as the present embodiment), a storage cell is produced using a current collector including a support layer containing a resin material and a conductive layer formed on at least one surface of the support layer. The conductive layer has better conductivity than the support layer. In this embodiment, the type of resin material is determined, for example, so that the density of the support layer is smaller than the density of the conductive layer. This can improve the energy density per unit mass of the storage cell [Wh / kg-storage cell] and / or the capacity per unit mass of the active material [mAh / g-active material] compared to conventional storage cells.

[0021] For example, conventionally, aluminum foil, copper foil, or the like having a thickness of about 8 to 20 μm has been used as the current collector. Therefore, in conventional storage cells, the ratio of the mass of the positive and negative electrode current collectors to the mass of the storage cell was 20 to 25%. In contrast, according to this embodiment, a part of the current collector is formed of a material (typically air or a resin material) having a lower density than aluminum foil or copper foil. As a result, a storage cell having excellent energy density per unit mass and / or capacity per unit mass of active material can be provided. For example, according to this embodiment, a storage cell having an energy density per unit mass of 350 [Wh / kg-storage cell] or more can be provided. In addition, the storage cell according to this embodiment has a high energy density per unit mass, and is therefore particularly suitable for use in aircraft.

[0022] The above-mentioned storage cell includes, for example, a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The above-mentioned current collector constitutes a part of the positive electrode and / or the negative electrode of the above-mentioned storage cell. For example, in the above-mentioned storage cell, the positive electrode includes the above-mentioned current collector and a layered positive electrode active material (sometimes referred to as a positive electrode active material layer) disposed on at least one surface of the current collector. The negative electrode includes the above-mentioned current collector and a layered negative electrode active material (sometimes referred to as a negative electrode active material layer) disposed on at least one surface of the current collector.

[0023] According to this embodiment, the support layer of the current collector constitutes all or part of the exterior of the storage cell. This reduces the mass of the storage cell compared to a case in which the storage cell has an exterior in addition to the laminate of the positive electrode, the separator, and the negative electrode. As a result, the energy density per unit mass of the storage cell [Wh / kg-storage cell] and / or the capacity per unit mass of the active material [mAh / g-active material] can be improved. In addition, according to this embodiment, active material layers can be formed on both sides of at least one current collector included in the storage cell.

[0024] As described above, the support layer includes a resin material. The type of the resin material is not particularly limited, but is determined, for example, according to the positive electrode active material, the negative electrode active material, the electrolyte, the temperature during the formation of the exterior of the storage cell, and the battery characteristics required for the storage cell, as well as a combination thereof. Any thermoplastic resin material may be used as the resin material. The melting point or softening point of the resin material may be lower than the melting point or softening point of the main component of the conductive layer. The support layer may be substantially composed of a thermoplastic resin material, or the support layer may be a thermoplastic resin material.

[0025] For example, after at least two electrodes constituting a battery are stacked with a separator interposed therebetween, a part of the support layer of the current collector included in each electrode is heated and pressed, and the support layers included in the two adjacent electrodes are welded together. This causes the two adjacent current collectors to be integrated. As a result, the positive electrode active material layer and the negative electrode active material layer disposed between the two current collectors are sealed by the two current collectors.

[0026] As described above, in this embodiment, a conductive layer is formed on the surface of the support layer. When the conductive layer is disposed on the peripheral portion of the support layer, the conductive layer may hinder the integration of the support layer. Therefore, the conductive layer of the current collector according to this embodiment is formed with an exposed portion that penetrates the conductive layer and exposes a part of the support layer. The conductive layer may be formed with a plurality of exposed portions.

[0027] The one or more exposed portions are, for example, disposed near the region where the support layer is integrated. In one embodiment, the entire region where the one or more exposed portions are formed is disposed inside the region where the support layer is integrated. In another embodiment, a portion of the region where the one or more exposed portions are formed overlaps with a portion of the region where the support layer is integrated. In yet another embodiment, the entire region where the support layer is integrated is disposed inside the region where the one or more exposed portions are formed.

[0028] As a result, according to the present embodiment, the two adjacent current collectors can be integrated better than when no exposed portion is formed in the conductive layer, and as a result, the positive electrode active material layer and the negative electrode active material layer are sealed better.

[0029] The method for integrating the at least two current collectors is not limited to heat welding, and in other embodiments, the at least two current collectors may be integrated by adhesion.

[0030] The storage cell may be an example of a battery. In one embodiment, the positive electrode and the negative electrode separated by a single separator may be an example of the first electrode and the second electrode. In this case, the positive electrode may be an example of one of the first electrode and the second electrode, and the negative electrode may be an example of the other of the first electrode and the second electrode. The positive electrode active material layer may be an example of one of the first active material layer and the second active material layer, and the negative electrode active material layer may be an example of the other of the first active material layer and the second active material layer. In another embodiment, when the battery includes a laminate of one or more positive electrodes, one or more separators, and one or more negative electrodes, the two electrodes arranged on the outermost side of the laminate may be an example of the first electrode and the second electrode. The two active material layers arranged on each of the two electrodes may be an example of the first active material layer and the second active material layer.

[0031] As described above, according to the present embodiment, for example, the amount of energy per weight in a rechargeable battery can be improved, and a rechargeable battery that is lighter and can store more power can be realized. The rechargeable battery can be brought to a disaster site, for example, and used to supply energy to disaster victims. Therefore, the laminate, electrode structure, and battery according to the present embodiment, as well as the manufacturing method thereof, can contribute to the achievement of Goal 7 "Affordable and clean energy" or Goal 13 "Take urgent action to combat climate change" of the Sustainable Development Goals (SDGs).

[0032] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0033] In this specification, when a numerical range is expressed as "A to B", the expression means A or more and B or less. In addition, "substituted or unsubstituted" means "substituted with any substituent or not substituted with any substituent". The type of the above-mentioned substituent is not particularly limited unless otherwise stated in the specification. In addition, the number of the above-mentioned substituents is not particularly limited unless otherwise stated in the specification.

[0034] (Overview of the Aircraft 100) 1 illustrates an example of a system configuration of an aircraft 100. In this embodiment, the aircraft 100 includes a storage battery 110, a power control circuit 120, one or more electric motors 130, one or more propellers 140, one or more sensors 150, and a control device 160. In this embodiment, the storage battery 110 includes one or more storage cells 112.

[0035] In this embodiment, the flying object 100 flies using electrical energy stored in the storage battery 110. Examples of the flying object 100 include an airplane, an airship or a balloon, a helicopter, a drone, and the like.

[0036] In this embodiment, the storage battery 110 receives electric energy from an external charging device (not shown) via the power control circuit 120, and stores the electric energy in one or more storage cells 112. In addition, the storage battery 110 supplies the electric energy stored in the one or more storage cells 112 to the electric motor 130 via the power control circuit 120.

[0037] In this embodiment, the storage cell 112 stores electric energy (sometimes referred to as charging the storage cell 112). Also, the storage cell 112 releases the stored electric energy (sometimes referred to as discharging the storage cell 112). The storage cell 112 may be a secondary battery.

[0038] The power storage cell 112 may contain an electrolytic solution or a gel electrolyte, or may not contain an electrolytic solution or a gel electrolyte. The electrolytic solution contains, for example, a supporting electrolyte salt and a solvent. The solvent may be an aqueous solvent or a non-aqueous solvent. The gel electrolyte contains, for example, a supporting electrolyte salt, an organic polymer compound, and an organic solvent.

[0039] The storage cell 112 may be an all-solid-state battery. The storage cell 112 may be an all-solid-state secondary battery. The all-solid-state secondary battery is a secondary battery that does not substantially contain the above-mentioned electrolytic solution or gel electrolyte, and includes, for example, a pair of electrodes and a solid electrolyte layer disposed between the pair of electrodes.

[0040] The secondary battery being substantially free of electrolytic solution or gel electrolyte means not only the case where the secondary battery does not contain electrolytic solution or gel electrolyte, but also the case where the secondary battery contains a small amount of electrolytic solution or gel electrolyte. Even if the constituent materials of the secondary battery dissolve in the solvent contained in the electrolytic solution or gel electrolyte, if the amount of the solvent contained in the secondary battery is small, the effect on the battery performance of the constituent materials of the secondary battery dissolving in the solvent can be ignored.

[0041] In one embodiment, the energy storage cell 112 does not include at least one of (i) an electrolyte solution containing a supporting electrolyte salt and a solvent, and (ii) a gel electrolyte containing a supporting electrolyte salt, an organic polymer compound, and an organic solvent. In another embodiment, the ratio of the mass [kg] of the electrolyte solution and the gel electrolyte to the mass [kg] of the organic compound used as the active material is less than 5%.

[0042] Examples of carrier ions in secondary batteries include lithium, sodium, potassium, magnesium, calcium, etc. Examples of secondary batteries include sodium ion secondary batteries, lithium ion secondary batteries, lithium metal secondary batteries, lithium air secondary batteries, lithium sulfur secondary batteries, magnesium ion secondary batteries, etc.

[0043] For example, a material that can store a large amount of charge per unit volume is often selected as an active material for a secondary battery mounted on a vehicle. On the other hand, in this embodiment, the storage cell 112 is mounted on the aircraft 100. Therefore, it is preferable that the active material used for the storage cell 112 is a material that can store a large amount of charge per unit mass.

[0044] The mass energy density of the storage cell 112 is preferably 350 [Wh / kg-storage cell] or more, more preferably 400 Wh / kg-storage cell] or more, more preferably 500 Wh / kg-storage cell] or more, even more preferably 600 Wh / kg-storage cell] or more, and even more preferably 700 Wh / g-storage cell] or more. This provides a storage cell that is particularly suitable for use as a power source for an aircraft.

[0045] The volumetric energy density of the storage cell 112 is 300 [Wh / m 3 - Storage cell] 1200 [Wh / m 3 - Storage cell] or less, 400 [Wh / m 3 - Storage cell] 1000 [Wh / m 3 When the storage cell 112 is mounted on the aircraft 100 as part of the power source of the aircraft 100, the volumetric energy density of the storage cell 112 may be 600 [Wh / m 3 - Storage cell] or less, 800 [Wh / m 3 -storage cell] or less.

[0046] The storage cell 112 may have a mass energy density within the above numerical range and a volume energy density within the above numerical range. This allows the storage cell, which is relatively difficult to use as a power source for a vehicle, to be used as a power source for an aircraft. The details of the storage cell 112 will be described later.

[0047] In this embodiment, the power control circuit 120 controls the input and output of power of the storage battery 110. The power control circuit 120 may control the input and output of power of the storage battery 110 based on an instruction from the control device 160. The power control circuit 120 includes, for example, a plurality of switching elements that operate based on a control signal from the control device 160.

[0048] In this embodiment, the electric motor 130 receives electric energy from the storage battery 110 via the power control circuit 120. The electric motor 130 rotates the propeller 140 using the electric energy received from the storage battery 110. In this way, the electric motor 130 can generate propulsion force for the flying object 100 using the electric energy stored in the storage cell 112.

[0049] In this embodiment, the sensor 150 measures various physical quantities related to the position and attitude of the flying object 100. Examples of sensors for measuring various physical quantities related to the position and attitude of the flying object 100 include a GPS signal receiver, an acceleration sensor, an angular acceleration sensor, and a gyro sensor. The sensor 150 may measure various physical quantities related to the state of the storage battery 110. Examples of sensors for measuring various physical quantities related to the state of the storage battery 110 include a temperature sensor, a current sensor, and a voltage sensor.

[0050] In this embodiment, the control device 160 controls the flying object 100. The control device 160 may control the input and output of power to the storage battery 110 by controlling the power control circuit 120. For example, the control device 160 controls the output current, output voltage, input current, input voltage, etc. of the storage battery 110. This allows the control device 160 to control the position and attitude of the flying object 100. The control device 160 may control the position and attitude of the flying object 100 by controlling the power control circuit 120 based on the output from the sensor 150.

[0051] The storage battery 110 may be an example of a secondary battery. The power storage cell 112 may be an example of a secondary battery. The electric motor 130 may be an example of a propulsion force generating device. The secondary battery may be an example of a battery.

[0052] (Outline of storage cell 112) An example of the power storage cell 112 will be described with reference to Fig. 2 and Fig. 3. Fig. 2 shows an example of an internal configuration of the power storage cell 112. Fig. 3 shows an example of a cross-sectional view of the power storage cell 112.

[0053] In this embodiment, the details of the storage cell 112, which is an example of a battery, will be described by taking as an example a case where the storage cell 112 is a laminated type (sometimes referred to as a pouch type) secondary battery. However, it should be noted that the battery or storage cell is not limited to a laminated type secondary battery. When the battery is a secondary battery, any type of storage cell may be used. The battery may be a primary battery.

[0054] (Energy storage cell) 2 , in this embodiment, the energy storage cell 112 includes a terminal 202, a terminal 204, and an exterior 206. In this embodiment, a laminate 212 and a liquid or gel electrolyte 214 are housed inside the exterior 206. In this embodiment, the laminate 212 includes one positive electrode 220, two separators 230, and two negative electrodes 240.

[0055] According to this embodiment, the negative electrode 240, the separator 230, the positive electrode 220, the separator 230, and the negative electrode 240 are laminated in this order. Each of the two separators 230 separates the positive electrode 220 and the negative electrode 240 that sandwich the separator. In this embodiment, one surface of the separator 230 contacts the positive electrode active material layer 224. The other surface of the separator 230 contacts the negative electrode active material layer 244.

[0056] In this embodiment, the terminal 202 is a positive terminal of the energy storage cell 112. The terminal 202 is electrically connected to a positive electrode current collector 222 included in the stack 212. In this embodiment, the terminal 204 is a negative electrode terminal of the energy storage cell 112. The terminal 204 is electrically connected to each of the two negative electrode current collectors 242 included in the stack 212.

[0057] In this embodiment, the exterior 206 seals the positive electrode current collector 222 and the negative electrode active material layer 244 included in the laminate 212. The exterior 206 may seal the positive electrode current collector 222, the negative electrode active material layer 244, and the separator 230 included in the laminate 212. In this embodiment, a part or all of the exterior 206 is composed of two negative electrode current collectors 242 arranged on the outermost side of the laminate 212. This can improve the energy density per unit mass of the storage cell 112 [Wh / kg-storage cell] and / or the capacity per unit mass of the active material included in the storage cell 112 [mAh / g-active material].

[0058] Also, according to this embodiment, an active material layer can be formed on both sides of one or more electrodes except for the two electrodes arranged on the outermost side of the laminate 212. More specifically, two negative electrode current collectors 242 are arranged on the outermost side of the laminate 212, and a positive electrode active material layer 224 is formed on both sides of the positive electrode current collector 222. In contrast, according to the electrochemical cell disclosed in JP 2021-012891 A, the positive electrode active material layer is formed only on one side of the positive electrode current collector. Similarly, the negative electrode active material layer is formed only on one side of the negative electrode current collector.

[0059] In this embodiment, the type of the electrolyte 214 is not particularly limited. Any known electrolyte may be used as the electrolyte 214. The liquid or gel electrolyte 214 may contain any known solvent. Examples of the solvent include ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), butylene carbonate (BC), fluoroethylene carbonate (FEC), γ-butyrolactone, sulfolane, acetonitrile, 1,2-dimethoxymethane, 1,3-dimethoxypropane, diethyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, and mixtures thereof.

[0060] (Positive electrode current collector) In this embodiment, the positive electrode current collector 222 holds the positive electrode active material layer 224. The positive electrode current collector 222 has an electric resistance of, for example, 0.01 mΩ to 1 Ω. The density of the positive electrode current collector 222 is, for example, 1.1 to 2.0 g / cm 3 This makes the mass of the positive electrode 220 very light, and the mass energy density of the power storage cell 112 is high.

[0061] In this embodiment, at least a portion of the positive electrode collector 222 is made of a material having a lower density than a metal. At least a portion of the positive electrode collector 222 may be made of a material having a lower density than aluminum. For example, at least a portion of the positive electrode collector 222 is made of a resin. For example, the positive electrode collector 222 includes a conductive layer containing a conductive material and a support layer that supports the conductive layer. The conductive layer and the support layer will be described in detail later.

[0062] In this embodiment, the positive electrode active material layer 224 is formed on at least one surface of the positive electrode current collector 222. The thickness of the positive electrode active material layer 224 per one surface of the positive electrode current collector 222 may be more than 0 and not more than 200 μm, may be 1 or more and not more than 100 μm, or may be 5 or more and not more than 50 μm.

[0063] The positive electrode active material layer 224 includes, for example, a positive electrode active material and a binding material (sometimes referred to as a binder). The positive electrode active material layer 224 may further include at least one of a conductive material and an ion conductive material. The positive electrode active material layer 224 may include a positive electrode active material and an ion conductive material.

[0064] In one embodiment, the positive electrode active material layer 224 is formed by applying a slurry containing the material constituting the positive electrode active material layer 224 and a solvent onto at least one surface of the positive electrode current collector 222, and drying the slurry. Examples of the above-mentioned solvent include various solvent substances or mixtures thereof. The type of the above-mentioned solvent substance is not particularly limited, but examples of the above-mentioned solvent substance include N-methylpyrrolidone (NMP) and water. In another embodiment, the positive electrode active material layer 224 is formed by mixing the materials constituting the positive electrode active material layer 224, forming them into a sheet, and pressing the sheet-shaped mixture onto at least one surface of the positive electrode current collector 222.

[0065] (Cathode active material) As the positive electrode active material contained in the positive electrode active material layer 224, various materials capable of absorbing and releasing carrier ions of the power storage cell 112 are used. The positive electrode active material may be a single or multiple types of organic compounds, a single or multiple types of inorganic compounds, or a mixture thereof.

[0066] Examples of inorganic compounds used as the positive electrode active material (sometimes referred to as inorganic positive electrode active materials) include metal oxides, metal silicates, metal phosphates, metal borates, etc. Examples of the metals include transition metals such as V, Mn, Ni, and Co.

[0067] As the organic compound used as the positive electrode active material (sometimes referred to as an organic positive electrode active material), various redox active compounds are used as the organic positive electrode active material. Examples of the organic positive electrode active material include conjugated polymers, disulfides, quinones, localized radicals, and non-localized radicals.

[0068] The organic positive electrode active material may be at least one compound selected from the group consisting of aromatic hydrocarbons, aromatic heterocyclic compounds, alkenes substituted with one or more cyano groups, disulfides, and derivatives thereof, as well as compounds containing structures or structural units derived therefrom. When the organic positive electrode active material is a compound containing the above structural units, its degree of polymerization may be 100 or less. The above derivatives may be compounds in which one or more hydrogens are substituted with a ketone group, an OH group, an OM group (M is a metal. Examples of M include a carrier metal of a battery, an alkali metal, an alkaline earth metal, etc.), a nitro group, etc.

[0069] The organic positive electrode active material may be at least one compound selected from the group consisting of a compound having a structure in which at least two oxygen atoms are bonded to a benzene ring, a compound having a structure in which at least two hydroxyl groups are bonded to a benzene ring, a compound having a structure in which at least two carbon atoms of a benzene ring are replaced with nitrogen atoms, a compound having a structure in which at least two cyano groups are bonded to a carbon double bond, a compound having a disulfide bond, and derivatives thereof, as well as compounds having structures or structural units derived therefrom. When the organic positive electrode active material is a compound having the above structural units, its degree of polymerization may be 100 or less. The above derivatives may be compounds in which one or more hydrogen atoms are replaced by a ketone group, an OH group, an OM group (M is a metal. Examples of M include a carrier metal of a battery, an alkali metal, an alkaline earth metal, etc.), a nitro group, etc.

[0070] (Binding material) The binder material contained in the positive electrode active material layer 224 binds the materials constituting the positive electrode active material layer 224 and maintains the electrode shape of the positive electrode 220. As the binder material, for example, various polymer materials are used. Examples of the polymer materials include carboxymethyl cellulose, styrene-butadiene rubber, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyacrylic acid, polyethylene oxide (PEO), poly(3,4-ethylenedioxythiophene) (PEDOT), and derivatives thereof.

[0071] (Conductive materials) The conductive material contained in the positive electrode active material layer 224 improves the conductivity of the positive electrode active material layer 224. This reduces the resistance of the positive electrode 220. The conductive material is not particularly limited as long as it is a material having electronic conductivity. Examples of the conductive material include carbon-based materials, metal-based materials, and conductive polymer materials. These conductive materials may be used alone, or two or more conductive assistants may be used in combination.

[0072] Examples of carbon-based materials include graphite, carbon black (e.g., acetylene black, ketjen black, etc.), coke, amorphous carbon, carbon fiber, carbon nanotube, graphene, etc. Examples of metal-based materials include aluminum, gold, silver, copper, iron, platinum, chromium, tin, indium, titanium, nickel, etc. Examples of conductive polymer materials include polyphenylene derivatives, etc.

[0073] (Conductive materials) The conductive material contained in the positive electrode active material layer 224 improves the conductivity of carrier ions in the positive electrode active material layer 224. For example, various solid electrolytes are used as the conductive material. Examples of the solid electrolyte include sulfide-based solid electrolytes, oxide-based solid electrolytes, and polymer solid electrolytes. A polymer solid electrolyte may be used as the conductive material. Examples of the polymer solid electrolyte include polyethylene oxide (PEO), poly(3,4-ethylenedioxythiophene) (PEDOT), and at least one compound selected from derivatives thereof.

[0074] (Separator) In this embodiment, the separator 230 is disposed between the positive electrode 220 and the negative electrode 240 to separate the positive electrode 220 and the negative electrode 240. More specifically, the separator 230 is disposed between the positive electrode active material layer 224 and the negative electrode active material layer 244 to separate the positive electrode active material layer 224 and the negative electrode active material layer 244. In addition, the separator 230 ensures the conductivity of carrier ions between the positive electrode 220 and the negative electrode 240.

[0075] Any known separator can be used as the separator 230. For example, a porous material, a solid electrolyte, or the like can be used as the separator 230. The thickness of the separator 230 is not particularly limited, but is preferably 10 to 50 μm.

[0076] In this embodiment, the negative electrode current collector 242 holds the negative electrode active material layer 244. The negative electrode current collector 242 may have a similar configuration to the positive electrode current collector 222. For example, the negative electrode current collector 242 includes a conductive layer containing a conductive material and a support layer that supports the conductive layer.

[0077] In this embodiment, the negative electrode active material layer 244 is formed on at least one surface of the negative electrode current collector 242. The thickness of the negative electrode active material layer 244 per one surface of the negative electrode current collector 242 may be more than 0 and not more than 200 μm, may be 1 or more and not more than 100 μm, or may be 5 or more and not more than 50 μm.

[0078] The negative electrode active material layer 244 includes, for example, a negative electrode active material and a binding material (sometimes referred to as a binder). The negative electrode active material layer 244 may further include at least one of a conductive material and an ion conductive material. The negative electrode active material layer 244 may include a negative electrode active material and an ion conductive material.

[0079] In one embodiment, the negative electrode active material layer 244 is produced by applying a slurry containing the material constituting the negative electrode active material layer 244 and an organic solvent onto at least one surface of the negative electrode current collector 242, and drying the slurry. Examples of the above-mentioned solvent include various solvent substances or mixtures thereof. The type of the above-mentioned solvent substance is not particularly limited, but examples of the above-mentioned solvent substance include N-methylpyrrolidone (NMP) and water. In another embodiment, the negative electrode active material layer 244 is formed by mixing the materials constituting the negative electrode active material layer 244, forming them into a sheet, and pressing the sheet-shaped mixture onto at least one surface of the negative electrode current collector 242.

[0080] (Negative electrode active material) As the negative electrode active material contained in the negative electrode active material layer 244, various materials capable of absorbing and releasing carrier ions of the power storage cell 112 are used. The negative electrode active material may be an inorganic compound or an organic compound. These negative electrode active materials may be used alone, or two or more types of negative electrode active materials may be combined. For example, a metal foil capable of releasing carrier ions of the power storage cell 112 is used as the negative electrode active material layer 244. This improves the mass energy density of the power storage cell 112.

[0081] Examples of inorganic compounds used as the negative electrode active material (sometimes referred to as inorganic negative electrode active materials) include (i) carrier metals and alloys containing the carrier metals, (ii) tin, silicon and alloys containing the carrier metals, (iii) silicon oxides, and (iv) titanium oxides. For example, when the power storage cell 112 is a lithium secondary battery, metallic lithium, lithium titanium oxide (LTO), and the like are used as the negative electrode active material. When a material not containing a carrier metal is used as the negative electrode active material, the material may be pre-doped with the carrier metal.

[0082] The organic compound used as the negative electrode active material (sometimes referred to as an organic negative electrode active material) may be at least one compound selected from the group consisting of aromatic heterocyclic compounds and derivatives thereof, and compounds containing structures or structural units derived therefrom. When the organic negative electrode active material is a compound containing the above structural units, its degree of polymerization may be 100 or less. The above derivatives may be compounds in which one or more hydrogens are substituted with a ketone group, an OH group, an OM group (M is a metal. Examples of M include a carrier metal of a battery, an alkali metal, an alkaline earth metal, etc.), a nitro group, etc.

[0083] As described above, the negative electrode active material layer 244 may include a foil-shaped carrier metal. For example, the negative electrode active material layer 244 includes a lithium metal foil. This provides the carrier metal to the power storage cell 112. The thickness of the metal foil may be 1 to 200 μm, 10 to 100 μm, or 20 to 50 μm. The thickness and / or mass of the metal foil may be determined depending on the content of the positive electrode active material in the positive electrode active material layer 224.

[0084] (Binding material) The binder material contained in the negative electrode active material layer 244 binds the materials constituting the negative electrode active material layer 244 and maintains the electrode shape of the negative electrode 240. As the binder material, for example, various polymer materials are used. Examples of the polymer materials include carboxymethyl cellulose, styrene-butadiene rubber, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyacrylic acid, polyethylene oxide (PEO), poly(3,4-ethylenedioxythiophene) (PEDOT), and derivatives thereof.

[0085] (Conductive materials) The conductive material contained in the negative electrode active material layer 244 improves the conductivity of the negative electrode active material layer 244. This reduces the resistance of the negative electrode 240. The conductive material is not particularly limited as long as it is a material having electronic conductivity. Examples of the conductive material include carbon-based materials, metal-based materials, and conductive polymer materials. These conductive materials may be used alone, or two or more conductive assistants may be combined.

[0086] Examples of carbon-based materials include graphite, carbon black (e.g., acetylene black, ketjen black, etc.), coke, amorphous carbon, carbon fiber, carbon nanotube, graphene, etc. Examples of metal-based materials include aluminum, gold, silver, copper, iron, platinum, chromium, tin, indium, titanium, nickel, etc. Examples of conductive polymer materials include polyphenylene derivatives, etc.

[0087] (Conductive materials) The conductive material contained in the negative electrode active material layer 244 improves the conductivity of carrier ions in the negative electrode active material layer 244. For example, various solid electrolytes are used as the conductive material. Examples of the solid electrolyte include sulfide-based solid electrolytes, oxide-based solid electrolytes, and polymer solid electrolytes. A polymer solid electrolyte may be used as the conductive material. Examples of the polymer solid electrolyte include at least one compound selected from polyethylene oxide (PEO), poly(3,4-ethylenedioxythiophene) (PEDOT), and derivatives thereof.

[0088] 3, in this embodiment, two negative electrode current collectors 242 included in two negative electrodes 240 arranged on the outermost sides of the laminate 212 are integrated at least in a portion of their periphery (sometimes referred to as an integrated region 320). According to this embodiment, in the integrated region 320, the two negative electrode current collectors 242 are integrated via the positive electrode current collector 222. As a result, a portion of each periphery of the two negative electrode current collectors 242 and a portion of the periphery of the positive electrode current collector 222 are integrated.

[0089] According to this embodiment, the two negative electrode current collectors 242 integrated in the integrated region 320 constitute the exterior 206. In this embodiment, the exterior 206 is constituted by the two negative electrode current collectors 242 and the positive electrode current collector 222.

[0090] As a result, the two negative electrode current collectors 242 seal two positive electrode active material layers 224, two separators 230, and two negative electrode active material layers 244. Similarly, one of the two negative electrode current collectors 242 and the positive electrode current collector 222 seal one positive electrode active material layer 224, one separator 230, and one negative electrode active material layer 244.

[0091] The positive electrode 220 may be an example of an electrode. The positive electrode current collector 222 may be an example of a current collector. The positive electrode active material layer 224 may be an example of an active material layer. The negative electrode 240 may be an example of an electrode. The negative electrode current collector 242 may be an example of a current collector. The negative electrode active material layer 244 may be an example of an active material layer.

[0092] One of the positive electrode 220 and the negative electrode 240 arranged via a specific separator 230 may be an example of a first electrode, and the other of the positive electrode 220 and the negative electrode 240 arranged via the specific separator 230 may be an example of a second electrode. The positive electrode current collector 222 included in the positive electrode 220 may be an example of one of the first current collector and the second current collector, and the negative electrode current collector 242 included in the negative electrode 240 may be an example of the other of the first current collector and the second current collector. The positive electrode active material layer 224 included in the positive electrode 220 may be an example of one of the first active material layer and the second active material layer, and the negative electrode active material layer 244 included in the negative electrode 240 may be an example of the other of the first active material layer and the second active material layer.

[0093] The two negative electrodes 240 may be an example of an electrode disposed on the outermost side of the laminate 212. One of the two negative electrodes 240 may be an example of a first electrode, and the other of the two negative electrodes 240 may be an example of a second electrode. The negative electrode current collector 242 included in one of the two negative electrodes 240 may be an example of one of the first current collector and the second current collector, and the negative electrode current collector 242 included in the other of the two negative electrodes 240 may be an example of the other of the first current collector and the second current collector. The negative electrode active material layer 244 included in one of the two negative electrodes 240 may be an example of one of the first active material layer and the second active material layer, and the negative electrode active material layer 244 included in the other of the two negative electrodes 240 may be an example of the other of the first active material layer and the second active material layer.

[0094] (An example of another embodiment) In this embodiment, the details of the storage cell 112 have been described by taking as an example a case in which the laminate 212 includes one positive electrode 220, two negative electrodes 240, and two separators 230 that isolate the positive electrode 220 and the negative electrode 240, respectively. However, the storage cell 112 is not limited to this embodiment.

[0095] In another embodiment, for example, the laminate 212 includes two positive electrodes 220, one negative electrode 240, and two separators 230 that separate the positive electrodes 220 and the negative electrodes 240. In yet another embodiment, the laminate 212 includes n positive electrodes 220, m negative electrodes 240, and k separators 230 that separate the positive electrodes 220 and the negative electrodes 240. Each of n, m, and k is an integer of 2 or more.

[0096] In the present embodiment, the details of the storage cell 112 have been described by taking as an example a case in which the storage cell 112 includes a liquid or gel electrolyte 214. However, the storage cell 112 is not limited to this embodiment. In other embodiments, the storage cell 112 may not substantially include a liquid or gel electrolyte 214. In this case, the separator 230 may include a solid electrolyte, or may be substantially composed of a solid electrolyte.

[0097] (Overview of Positive Electrode Current Collector 222 and / or Negative Electrode Current Collector 242) An example of the current collector 400 will be described with reference to Figures 4, 5, 6, 7, and 8. The current collector 400 is used as the positive electrode current collector 222 and / or the negative electrode current collector 242, for example.

[0098] FIG. 4 shows an example of a current collector 400. FIG. 4 shows an example of a top view of the current collector 400. FIG. 5 shows an example of an AA cross section of the current collector 400. FIG. 6 shows an example of a BB cross section of the current collector 400. FIG. 7 shows an example of a positional relationship between each part of the current collector 400. FIG. 8 shows an example of a positional relationship between each part of the current collector 400 and other members of the energy storage cell 112.

[0099] (Structure of current collector 400) 4, in this embodiment, current collector 400 includes support layer 420 and conductive layer 440. In this embodiment, details of current collector 400 will be described taking as an example a case where conductive layer 440 is not formed on peripheral portion 422 of support layer 420.

[0100] 5 and 6, in this embodiment, the support layer 420 has a first plane 522, a second plane 524, and a side surface 526. In this embodiment, the conductive layer 440 has a conductive layer 542 disposed on the first plane 522 of the support layer 420 and a conductive layer 544 disposed on the second plane 524 of the support layer 420. In this embodiment, one or more openings 450 are formed in the conductive layer 542. In this embodiment, one or more openings 550 are formed in the conductive layer 544.

[0101] 5, 6 and 7, in this embodiment, each of the conductive layers 542 and 544 includes a current collecting portion 562 and a tab portion 564. In this embodiment, the tab portion 564 of each of the conductive layers 542 and 544 includes a connection region 566 and an exposed region 568.

[0102] In this embodiment, the support layer 420 has a main body region 762 that supports the current collecting portion 562 and the exposed region 568 of the tab portion 564. The main body region 762 may have any shape. The integrated region 320 is set inside the main body region 762. The support layer 420 also has a protruding region 764 that supports the connection region 566 of the tab portion 564. The protruding region 764 is disposed outside the integrated region 320. The protruding region 764 protrudes from a part of the outer edge of the main body region 762 toward the outside of the main body region 762. The protruding region 764 may have any shape.

[0103] A connection region 566 of the tab portion 564 is connected to the terminal 202 or the terminal 204, or to a wiring (not shown) that electrically connects the terminal 202 or the terminal 204 to the conductive layer 440. One or more openings 450 are formed in the exposed region 568 of the tab portion 564 of the conductive layer 542. One or more openings 550 are formed in the exposed region 568 of the tab portion 564 of the conductive layer 544.

[0104] 8, in this embodiment, the integrated region 320 described above is set in at least a part of the peripheral portion 422 of the support layer 420 and in the exposed region 568 of the conductive layer 440. In the peripheral portion 422 and the exposed region 568, the resin material contained in the support layer 420 is exposed on the surface of the current collector 400 without being covered by the conductive layer 440. As a result, for example, when the integrated region 320 is heated and pressed in a state where at least two current collectors 400 are stacked, the resin material contained in each of the at least two support layers 420 melts and is integrated.

[0105] 8, in this embodiment, the current collecting portion 562 of at least one of the conductive layers 542 and 544 has an active material region 840 in which the positive electrode active material layer 224 or the negative electrode active material layer 244 is disposed. For example, when the current collector 400 is used as a current collector for an electrode disposed on the outermost side of the laminate 212, the current collecting portion 562 of the conductive layer 542 or the conductive layer 544 has the active material region 840. For example, when the current collector 400 is used as a current collector for an electrode other than the electrode disposed on the outermost side of the laminate 212, the current collecting portions 562 of both the conductive layer 542 and the conductive layer 544 have the active material region 840.

[0106] (Explanation of each part of the current collector 400) In this embodiment, the support layer 420 supports the conductive layer 542 and the conductive layer 544. This suppresses damage to the conductive layer 542 and the conductive layer 544. The density of the support layer 420 is lower than the density of the conductive layer 542 and the conductive layer 544. For example, the support layer 420 is made of a material having a density lower than the density of the conductive layer 542 or the conductive layer 544. The support layer 420 may be a sheet containing a resin material, or may be a sheet-like resin material.

[0107] The resin material may be a thermoplastic resin or a thermosetting resin. The support layer 420 may be made of a single type of resin material or may contain multiple types of resin materials. As described above, when a portion of the stacked multiple current collectors 400 is integrated by welding, it is preferable that the resin material mainly contains a thermoplastic resin or is substantially made of a thermoplastic resin. The melting point or softening point of the resin material may be lower than the melting point or softening point of the main component of the conductive layer 440.

[0108] The conductivity of the support layer 420 is not particularly limited, but the conductivity of the support layer 420 may be smaller than the conductivity of the conductive layer 542 or the conductive layer 544. The thickness of the support layer 420 is not particularly limited, but the thickness of the support layer 420 may be larger than the thickness of the conductive layer 542 or the conductive layer 544. When the thickness of the support layer 420 is large, the mass of the support layer 420 also becomes large. Therefore, when the support layer 420 is a sheet-shaped resin material, the thickness of the support layer 420 may be 10 μm or less, preferably 7 μm or less, and more preferably 5 μm or less.

[0109] In this embodiment, the conductive layer 440 is formed on at least one surface of the support layer 420. In this embodiment, the conductive layer 440 has better electrical conductivity than the support layer 420.

[0110] In this embodiment, the conductive layer 542 and the conductive layer 544 include a conductive material. The conductive material may have a higher electrical conductivity than the resin material contained in the support layer 420. The conductive material has a resistivity of 8.0×10 -8The conductive material may be a material having a resistance of 0.1 to 1.0 kPa (Ω·m) or more. The conductive material may be a metal. Examples of the metal include aluminum, stainless steel, nickel, and alloys thereof. Examples of stainless steel include SUS-430 and SUS-304. The conductive material may be aluminum.

[0111] The thickness of the conductive layer 542 and / or the conductive layer 544 (shown as the length in the vertical direction in FIG. 5 or FIG. 6) may be 0.05 μm to 7 μm. The thickness of the conductive layer 542 and / or the conductive layer 544 may be 0.05 μm to 5 μm, 0.1 μm to 3 μm, 0.1 μm to 2 μm, or 0.5 μm to 1 μm. The thickness of the conductive layer 542 and / or the conductive layer 544 may be 0.05 μm to 4 μm, 0.05 μm to 3 μm, 0.05 μm to 2 μm, or 0.05 μm to 1 μm. The thickness of the conductive layer 542 and / or the conductive layer 544 is preferably 0.1 μm to 5 μm, and more preferably 0.1 μm to 1 μm.

[0112] Even a relatively thin commercially available aluminum foil has a thickness of 6 to 10 μm. Therefore, by providing the current collector 400 with the conductive layer 542 and / or the conductive layer 544 having a thickness of 5 μm or less, the energy density per unit mass of the storage cell [Wh / kg-storage cell] is improved compared to when a commercially available aluminum foil is used as the conductive layer 542 and / or the conductive layer 544.

[0113] At least one of the conductive layer 542 and / or the conductive layer 544 may be an aluminum layer or foil having the above-mentioned thickness. The aluminum layer or foil may be disposed on the surface of the support layer 420 by pasting, or may be formed on the surface of the support layer 420 by a vapor deposition method, a deposition method, or the like.

[0114] When the conductive layer 542 and / or the conductive layer 544 has a thickness of 7 μm or less, the mass energy density of the storage cell 112 is improved. When the conductive layer 542 and / or the conductive layer 544 has a thickness of 5 μm or less, the mass energy density of the storage cell 112 is further improved. When the conductive layer 542 and / or the conductive layer 544 has a thickness of 1 μm or less, the mass energy density of the storage cell 112 is significantly improved. In general, when the thickness of the conductive layer is 0.1 μm or less or less than 0.1 μm, the conductive layer is easily damaged. However, the conductive layer 542 and the conductive layer 544 according to this embodiment are supported by the support layer 420. Therefore, even when the thickness of the conductive layer 542 and / or the conductive layer 544 is about 0.05 to 0.1 μm, damage to the conductive layer 542 and / or the conductive layer 544 can be suppressed.

[0115] In this embodiment, each of the one or more openings 450 penetrates the conductive layer 542 and exposes a portion of the support layer 420 without penetrating the support layer 420. Each of the one or more openings 450 may have any shape. Similarly, each of the one or more openings 550 penetrates the conductive layer 544 and exposes a portion of the support layer 420 without penetrating the support layer 420. Each of the one or more openings 550 may have any shape.

[0116] The opening 450 has a size of, for example, 10 to 1000 μm in equivalent circle diameter. The size of the opening 450 may be 100 to 700 μm in equivalent circle diameter, and is preferably 300 to 500 μm. The smaller the size of the opening 450, the smaller the electrical resistance of the conductive layer 542. On the other hand, the smaller the size of the opening 450, the lower the fluidity of the molten resin material in the opening, making it difficult to integrate a plurality of current collectors 400. When a plurality of openings 450 are formed in the conductive layer 542, the distance between the centers of the plurality of openings 450 may be 80 to 1000 μm, and is preferably 300 to 700 μm.

[0117] In the integrated region 320, the ratio of the total area of ​​the one or more openings 450 to the area of ​​the conductive layer 542 (sometimes referred to as the aperture ratio) may be 5 to 80%. The aperture ratio of the conductive layer 542 in the integrated region 320 is preferably 10 to 70%. The aperture ratio is calculated by multiplying the value obtained by dividing the total area of ​​the one or more openings 450 arranged inside the integrated region 320 by the area of ​​the overlapping region of the integrated region 320 and the conductive layer 542 by 100. The total area of ​​the one or more openings 450 arranged inside the integrated region 320 is calculated as the total area of ​​the overlapping portions between the integrated region 320 and each of the one or more openings 450.

[0118] Similarly, the opening 550 has a size of, for example, 0 to 1000 μm. The size of the opening 450 in terms of a circle equivalent diameter may be 100 to 700 μm, and is preferably 300 to 500 μm. When multiple openings 550 are formed in the conductive layer 544, the distance between the centers of the multiple openings 550 may be 80 to 1000 μm, and is preferably 300 to 700 μm.

[0119] In the integrated region 320, the ratio of the total area of ​​the one or more openings 550 to the area of ​​the conductive layer 544 (sometimes referred to as the aperture ratio) may be 5 to 80%. The aperture ratio of the conductive layer 544 in the integrated region 320 is preferably 10 to 70%. The aperture ratio is calculated by multiplying the value obtained by dividing the total area of ​​the one or more openings 550 arranged inside the integrated region 320 by the area of ​​the overlapping region of the integrated region 320 and the conductive layer 544 by 100. The total area of ​​the one or more openings 550 arranged inside the integrated region 320 is calculated as the total area of ​​the overlapping portions between the integrated region 320 and each of the one or more openings 550.

[0120] In this embodiment, the positive electrode active material layer 224 or the negative electrode active material layer 244 is formed on the current collecting portion 562. The current collecting portion 562 electrically connects the positive electrode active material layer 224 or the negative electrode active material layer 244 to the tab portion 564.

[0121] In this embodiment, the tab portion 564 is formed to extend from a part of the current collecting portion 562 toward the outside of the current collecting portion 562. The tab portion 564 electrically connects the current collecting portion 562 to the terminal 202 or the terminal 204. The width Wt of the tab portion 564 may be smaller than the width Wb of the current collecting portion 562. The length Lt of the tab portion 564 may be smaller than the length Lb of the current collecting portion 562.

[0122] In the present embodiment, the position of the connection region 566 in the tab portion 564 is not particularly limited, but the connection region 566 is disposed, for example, at an end of the tab portion 564. The connection region 566 may be disposed at a position farther away from the boundary between the current collecting portion 562 and the tab portion 564 than the exposed region 568.

[0123] In this embodiment, exposed region 568 is disposed near the boundary between current collecting portion 562 and tab portion 564, for example. In one embodiment, exposed region 568 is disposed such that at least a portion of exposed region 568 is inward of tab portion 564. In another embodiment, at least a portion of exposed region 568 is inward of current collecting portion 562. In yet another embodiment, exposed region 568 is disposed entirely inward of tab portion 564.

[0124] The width We of the exposed region 568 may be approximately the same as the width Wt of the tab portion 564, or may be smaller than the width Wt of the tab portion 564. When the integrated region 320 has a generally polygonal shape, the width Wt of the tab portion 564 may be smaller than the longest width Wpe of the peripheral portion 422 included in the side on which the tab portion 564 is disposed, among the multiple sides constituting the generally polygonal shape. The length Le of the exposed region 568 may be smaller than the length Lt of the tab portion 564.

[0125] The widths Wbr and Wbl of the peripheral portion 422 adjacent to the current collecting portion 562 may be 0.5 mm or more. This makes it possible to easily form the integrated region 320 having sufficient strength.

[0126] The length Lpb of the peripheral portion 422 adjacent to the current collecting portion 562 may be 0.5 mm or more. This makes it possible to easily form the integrated region 320 having sufficient strength.

[0127] The length Lpe of the peripheral portion 422 adjacent to the current collecting portion 562 may be 0.5 mm or more. This allows the integrated region 320 having sufficient strength to be easily formed. The length Lpe may be approximately the same as the length Lpb, or may be greater than the length Lpb.

[0128] The widths Wtr and Wtl of the peripheral portion 422 adjacent to the tab portion 564 are not particularly limited, but the widths Wtr and Wtl may be 0.5 mm or more. The length Lpt of the peripheral portion 422 adjacent to the tab portion 564 is not particularly limited, but the length Lpt may be 0.5 mm or more.

[0129] The width Wjr of the integrated region 320 may be approximately the same as the width Wbr of the peripheral portion 422 adjacent to the current collecting portion 562, or may be smaller than the above-mentioned width Wbr. The width Wjl of the integrated region 320 may be approximately the same as the width Wbl of the peripheral portion 422 adjacent to the current collecting portion 562, or may be smaller than the above-mentioned width Wbl. The length Ljb of the integrated region 320 may be approximately the same as the length Lpb of the peripheral portion 422 adjacent to the current collecting portion 562, or may be smaller than the above-mentioned length Lpb. The length Ljb of the integrated region 320 may be approximately the same as the above-mentioned length Ljb, or may be different from the above-mentioned length Ljb. When the integrated region 320 has an approximately polygonal shape, the length Ljt of the integrated region 320 on the side on which the tab portion 564 is arranged among the multiple sides constituting the approximately polygonal shape may be larger than the above-mentioned length Ljb.

[0130] In this embodiment, active material region 840 is formed inside current collecting portion 562. Therefore, width Wa of active material region 840 may be approximately the same as width Wb of current collecting portion 562, or may be smaller than the above-mentioned width Wb. Length La of active material region 840 may be approximately the same as length Lb of current collecting portion 562, or may be smaller than the above-mentioned length Lb. The ratio of area Wa×La of active material region 840 to area Wb×Lb of current collecting portion 562 may be 1:1 to 1.5, and preferably 1:1 to 1:1.2. The above ratio may be 1:1 to 1:1.1.

[0131] The opening 450 may be an example of an exposed portion or a portion of an exposed portion. The opening 550 may be an example of an exposed portion or a portion of an exposed portion. One of the first plane 522 and the second plane 524 may be an example of one of the first surface and the second surface. The other of the first plane 522 and the second plane 524 may be an example of the other of the first surface and the second surface. One of the conductive layer 542 and the conductive layer 544 may be an example of one of the first conductive layer and the second conductive layer. The other of the conductive layer 542 and the conductive layer 544 may be an example of the other of the first conductive layer and the second conductive layer. The current collecting portion 562 may be an example of a main body portion. The main body portion may be an example of a main body member. The tab portion 564 may be an example of an extension portion. The extension portion may be an example of an extension member. The exposed region 568 may be an example of an exposed portion.

[0132] (An example of another embodiment) In the present embodiment, details of the current collector 400 have been described by taking as an example a case in which the exposed region 568 is formed in the overlapping portion between the tab portion 564 of the conductive layer 440 and the integrated region 320, and the exposed region 568 is not formed in the current collecting portion 562 of the conductive layer 440. However, the current collector 400 is not limited to the present embodiment.

[0133] In another embodiment, the exposed region 568 is formed not only in the overlapping portion between the conductive layer 440 and the integrated region 320, but also in a region of the conductive layer 440 other than the overlapping portion. This improves the degree of freedom in designing the energy storage cell 112 and / or the current collector 400. Also, the positioning accuracy of the opening 450, the opening 550, and / or the integrated region 320 may be reduced. As a result, for example, the manufacturing process of the energy storage cell 112 and / or the current collector 400 may be simplified.

[0134] In the present embodiment, the details of the current collector 400 have been described by taking as an example a case in which openings are formed in both the conductive layer 542 and the conductive layer 544 of the conductive layer 440. However, the current collector 400 is not limited to this embodiment. In other embodiments, openings are formed in at least one of the conductive layer 542 and the conductive layer 544 of the conductive layer 440.

[0135] In the present embodiment, the details of the current collector 400 have been described by taking as an example a case where the support layer 420 does not have a through hole penetrating the support layer 420. However, the current collector 400 is not limited to the present embodiment. In another embodiment, the support layer 420 has a through hole penetrating the support layer 420. This improves the energy density per unit mass [Wh / kg-power storage cell] of the power storage cell 112. The through hole may be formed in a region other than the exposed region 568 of the support layer 420, or may be formed inside the exposed region 568 of the support layer 420. When the through hole is formed inside the exposed region 568 of the support layer 420, the through hole is formed so that a part of the support layer 420 is exposed from an opening arranged in the exposed region 568.

[0136] 9 illustrates an example of a top view of a current collector 900. The current collector 900 may be used, for example, as the positive current collector 222 and / or the negative current collector 242.

[0137] Current collector 900 may be another example of current collector 400. Current collector 900 differs from current collector 400 in that (i) one or more through holes 950 penetrating support layer 420, conductive layer 542, and conductive layer 544 are formed in connection region 566, and (ii) a conductive member 952 that electrically connects conductive layer 542 and conductive layer 544 is disposed inside through hole 950. Except for the above differences, current collector 900 may have the same configuration as current collector 400.

[0138] In this embodiment, each of the one or more through holes 950 penetrates a part of the tab portion 564 of the conductive layer 542, penetrates a part of the support layer 420, and penetrates a part of the tab portion 564 of the conductive layer 544. The through hole 950 differs from the opening 450 or the opening 550 in that it penetrates the support layer 420. The shape of the through hole 950 is not particularly limited, but examples of the shape of the through hole 950 include a substantially circular shape, a substantially elliptical shape, a substantially polygonal shape, and the like.

[0139] As described above, according to the present embodiment, one or more openings 450 are formed in the conductive layer 542, and one or more openings 550 are formed in the conductive layer 544. In this case, the average value of the circle-equivalent diameters of the one or more openings 450 or the average value of the circle-equivalent diameters of the one or more openings 550 may be different from the average value of the circle-equivalent diameters of the one or more through holes 950.

[0140] The ratio of the total area of ​​the one or more through holes 950 to the area of ​​the tab portion 564 (sometimes referred to as the through hole ratio) may be 10 to 50%. The through hole ratio of the tab portion 564 is preferably 10 to 30%. The through hole ratio of the tab portion 564 is calculated by dividing the total area of ​​the one or more through holes 950 formed in the tab portion 564 by the area of ​​the tab portion 564, and multiplying the obtained value by 100. Note that, when one or more openings 450 are formed in the tab portion 564, the area of ​​the tab portion 564 includes the area of ​​the one or more openings 450.

[0141] In the present embodiment, the conductive member 952 has a higher electrical conductivity than the support layer 420. The conductive member 952 includes a conductive material. The conductive material may have a higher electrical conductivity than the resin material included in the support layer 420. As the conductive material included in the conductive member 952, a material similar to the conductive material described in relation to the conductive layer 542 and / or the conductive layer 544 may be used. The composition of the conductive member 952 may be substantially the same as the composition of the conductive layer 542 and / or the conductive layer 544. For example, the conductive member 952 is made using the same raw material as the conductive layer 542 and / or the conductive layer 544 in the process of making the conductive layer 542 and / or the conductive layer 544 on the support layer 420.

[0142] According to one embodiment, the conductive member 952 is formed on the surface of the inner wall of the through hole 950. In this case, inside the through hole 950, there is a hole penetrating the conductive layer 542, the support layer 420, and the conductive layer 544. According to another embodiment, the conductive member 952 is formed so that the inside of the through hole 950 is filled with the conductive member 952.

[0143] The through hole 950 may be an example of a through hole that penetrates the first conductive layer, the support layer, and the second conductive layer. The conductive member 952 may be an example of a connection member.

[0144] (An example of another embodiment) In the present embodiment, the details of the current collector 400 have been described by taking as an example a case in which the through-hole 950 is disposed inside the connection region 566 and no through-hole 950 is formed outside the connection region 566. However, the current collector 400 is not limited to this embodiment. In other embodiments, the through-hole 950 may be formed not only inside the connection region 566 but also outside the connection region 566. Furthermore, a conductive member 952 may be formed inside at least a part of the through-hole 950 formed outside the connection region 566.

[0145] 10 is a schematic diagram of an example of a top view of a current collector 1000. The current collector 1000 may be used, for example, as the positive current collector 222 and / or the negative current collector 242.

[0146] Current collector 1000 may be another example of current collector 400 or current collector 900. Current collector 1000 differs from current collector 900 in that (i) current collector 1000 has smaller Lpb, Wbl, and Wbr than current collector 900, and (ii) exposed area 568 is set over substantially the entire current collecting portion 562. Except for the above differences, current collector 1000 may have the same configuration as current collector 900.

[0147] As described above, in this embodiment, the exposed region 568 is set over substantially the entire current collecting portion 562. As a result, a plurality of openings 450 are formed in the current collecting portion 562 of the conductive layer 542. For example, the plurality of openings 450 are arranged substantially evenly over the entire current collecting portion 562 of the conductive layer 542. Similarly, a plurality of openings 550 are formed in the current collecting portion 562 of the conductive layer 544. For example, the plurality of openings 550 are arranged substantially evenly over the entire current collecting portion 562 of the conductive layer 544.

[0148] In the present embodiment, at least a portion of the plurality of openings 450 and / or the plurality of openings 550 are disposed on at least a portion of the periphery of the current collecting portion 562. This improves the degree of freedom in designing the power storage cells 112 and / or the current collector 400. Also, the alignment precision required when producing the current collector 1000 can be reduced.

[0149] Fig. 11 shows an example of a method for producing a positive electrode 220 or a negative electrode 240 (sometimes simply referred to as an electrode). Fig. 11 shows an example of a method for producing a current collector or an electrode, taking as an example a case where a positive electrode 220 including a current collector 900 is produced. Fig. 11 also shows an example of a method for producing a current collector or an electrode, taking as an example a case where a plurality of current collectors 900 are produced using one resin sheet.

[0150] According to this embodiment, first, in step 1112 (step may be abbreviated as S), a resin sheet containing a thermoplastic resin is prepared. The resin sheet functions as support layer 420 for current collector 900. In the resin sheet, a plurality of through holes are formed in each of a plurality of regions that will become connection regions 566 of each of the plurality of current collectors 900.

[0151] Next, in S1114, S1116, and S1118, conductive layer 440 is formed on at least one surface of the resin sheet. First, in S1114, a masking layer for forming conductive layer 542 or conductive layer 544 is formed on at least one surface of the resin sheet in which the through-holes are formed. For example, a masking layer is formed on the resin sheet at a position corresponding to peripheral portion 422 of current collector 900 and opening 450 or opening 550. Any known material may be used as the material of the masking layer. Similarly, any known method may be used as the method for producing the masking layer.

[0152] Next, in S1116, a paste containing the raw material of the conductive layer 440 is applied to the surface of the resin sheet on which the masking layer is formed. The paste may be adjusted so that the paste penetrates into the through-holes formed in the resin sheet. As a result, the through-holes 950 having the conductive members 952 are formed.

[0153] Then, a process for drying the paste is performed. As a result, a conductive material is disposed on at least one surface of the resin sheet. Specifically, the conductive material contained in the paste forms the conductive layer 542 having the opening 450 and / or the conductive layer 544 having the opening 550.

[0154] After the paste is sufficiently dried, in S1118, the masking layer is removed from the resin sheet. This forms a conductive layer 542 having a peripheral portion 422 and an opening 450 on one side of the resin sheet. By a similar procedure, a conductive layer 544 having a peripheral portion 422 and an opening 550 can be formed on the other side of the resin sheet. This results in a current collector 900 to be used as the positive electrode current collector 222.

[0155] Next, in S1120, a positive electrode active material layer 224 containing a positive electrode active material is formed on at least one surface of the conductive layer 440. For example, a paste containing raw materials for the positive electrode active material layer 224 is applied onto the active material regions 840 of the conductive layers 542 and 544. The paste is dried to form the positive electrode active material layer 224.

[0156] As described above, according to the present embodiment, a plurality of electrodes are formed on a single resin sheet. Then, in S1122, each of the plurality of electrodes is cut out from the resin sheet. In this way, the positive electrode 220 is obtained.

[0157] S1114-S1118 may be an example of a conductive layer formation step. S1116 may be an example of a disposing step. S1112-S1118 may be an example of a method of producing a current collector or a step of preparing a current collector. S1120 may be an example of an active material layer formation step. Active material region 840 may be an example of at least a portion of a body portion or body member of a conductive layer.

[0158] (An example of another embodiment) In the present embodiment, the details of the method for manufacturing the current collector 900 have been described by taking as an example a case in which the conductive layer 542, the conductive layer 544, and the conductive member 952 are formed by applying a paste containing the raw material of the conductive layer 440 to the surface of a resin sheet on which a masking layer has been formed. However, the method for manufacturing the current collector 900 is not limited to this embodiment. In other embodiments, at least one of the conductive layer 542, the conductive layer 544, and the conductive member 952 may be formed by various deposition methods, plating methods, and the like.

[0159] In the present embodiment, the details of the method for manufacturing the electrode have been described by taking as an example a case in which an active material layer is formed on each of the active material regions 840 of the conductive layers 542 and 544. However, the method for manufacturing the electrode is not limited to this embodiment. In other embodiments, an active material layer may be formed so as to cover at least one of the conductive layers 542 and 544.

[0160] Fig. 12 shows a schematic diagram of an example of a method for producing the energy storage cell 112. According to this embodiment, first, one positive electrode 220 and two negative electrodes 240 are produced by the method for producing electrodes described in relation to Fig. 11. Also, a lead 1222 and a lead 1242 are produced. The lead 1222 is used, for example, to electrically connect an external device to the positive electrode current collector 222. The lead 1242 is used, for example, to electrically connect an external device to the negative electrode current collector 242.

[0161] In this embodiment, the positive electrode 220 has positive electrode active material layers 224 on both sides of the positive electrode current collector 222. In addition, a lead 1222 that functions as a positive electrode terminal of the power storage cell 112 is connected to a connection region 566 disposed on a tab portion 564 of the positive electrode current collector 222 of the positive electrode 220.

[0162] As described above, the conductive layer 542 is formed on the surface of the first plane 522 of the support layer 420 of the current collector 400 constituting the positive electrode current collector 222. Similarly, the conductive layer 544 is formed on the surface of the second plane 524 of the support layer 420. In this embodiment, for the purpose of simplifying the explanation, for example, the lead 1222 and the conductive layer 542 disposed in the connection region 566 of the tab portion 564 are joined by welding.

[0163] In this embodiment, each of the two negative electrodes 240 has a negative electrode active material layer 244 on one surface of a negative electrode current collector 242. For example, the negative electrode active material layer 244 is disposed on a surface of a conductive layer 542 of a current collector 400 constituting one of the negative electrodes 240 (for the purpose of simplifying the explanation, the negative electrode 240 disposed at the bottom in FIG. 12 may be referred to as the lower negative electrode 240). Similarly, the negative electrode active material layer 244 is disposed on a surface of a conductive layer 544 of a current collector 400 constituting the other negative electrode 240 (may be referred to as the upper negative electrode 240).

[0164] Next, the storage cell 112 is assembled using the negative electrode 240, the separator 230, the positive electrode 220 to which the lead 1222 is welded, the separator 230, the negative electrode 240, and the lead 1242. Specifically, first, the negative electrode 240, the separator 230, the positive electrode 220, the separator 230, and the negative electrode 240 are laminated in this order (sometimes referred to as a lamination stage). In addition, the lead 1242 is disposed on the surface of the conductive layer 544 disposed in the connection region 566 of the tab portion 564 of the lower negative electrode 240.

[0165] At this time, the above members are stacked such that the peripheral portions of the two negative electrode current collectors 242 and the peripheral portion of the positive electrode current collector 222 substantially coincide with each other. The above members are also stacked such that the connection regions 566 of the tab portions 564 of the two negative electrode current collectors 242 substantially coincide with each other. In this embodiment, the connection regions 566 of the tab portions 564 of the two negative electrode current collectors 242 and the lead 1242 have not yet been integrated.

[0166] As described above, the lead 1222 is disposed on the surface of the conductive layer 542 of the positive electrode 220. In addition, the lead 1242 is disposed on the surface of the negative electrode 240 on the lower side. As a result, in the embodiment shown in FIG. 12 , from the bottom up, (i) the lead 1242, (ii) the conductive layer 544, support layer 420, and conductive layer 542 of the lower negative electrode 240, (iii) the negative electrode active material layer 244 of the lower negative electrode 240, (iv) the separator 230, (v) the positive electrode active material layer 224 of the positive electrode 220, (vi) the conductive layer 544, support layer 420, and conductive layer 542 of the positive electrode 220, (vii) the positive electrode active material layer 224 of the positive electrode 220, and the lead 1222, (viii) the separator 230, (ix) the negative electrode active material layer 244 of the upper negative electrode 240, and (x) the conductive layer 544, support layer 420, and conductive layer 542 of the upper negative electrode 240 are laminated.

[0167] Next, the integration region 320 set in the peripheral portion of the positive electrode current collector 222 and the negative electrode current collector 242 is heated (sometimes referred to as an integration step). As a result, in the integration region 320, the resin material contained in the support layer 420 of the positive electrode current collector 222 and the resin material contained in the support layer 420 of the negative electrode current collector 242 are welded and integrated. As a result, one positive electrode current collector 222 and two negative electrode current collectors 242 are integrated, and the positive electrode active material layer 224, the separator 230, and the negative electrode active material layer 244 are sealed (sometimes referred to as a sealing step).

[0168] Thereafter, the connection regions 566 of the tab portions 564 of the two negative electrode current collectors 242 and the lead 1242 are integrated by welding, thereby obtaining the above-described storage cell 112.

[0169] (An example of another embodiment) In this embodiment, the details of the storage cell 112 have been described by taking as an example a case in which conductive layers are arranged on both sides of the two negative electrode collectors 242 arranged on the outermost sides of the storage cell 112. However, the storage cell 112 is not limited to this embodiment. In other embodiments, at least one of the two collectors arranged on the outermost sides of the storage cell 112 may not have a conductive layer on the outer surface. The type of electrode arranged on the outermost side of the storage cell 112 is determined, for example, so that the number of cheaper electrodes out of the positive electrodes 220 and the negative electrodes 240 is greater.

[0170] In the present embodiment, the method for producing the storage cell 112 has been described in detail, taking as an example a case in which the storage cell 112 includes one positive electrode 220 and two negative electrodes 240. However, the storage cell 112 is not limited to the present embodiment. In other embodiments, the storage cell 112 may be arranged such that the positive electrode active material layer 224 and the negative electrode active material layer 244 face each other with the separator 230 interposed therebetween, and the numbers of the positive electrodes 220 and the negative electrodes 240 are not particularly limited.

[0171] In this embodiment, the method for producing the energy storage cell 112 has been described in detail, taking as an example a case in which all the positive electrodes 220 include the positive electrode current collectors 222 and all the negative electrodes 240 include the negative electrode current collectors 242. However, the energy storage cell 112 is not limited to this embodiment. In other embodiments, at least a part of one or more electrodes other than the two electrodes arranged on the outermost sides of the energy storage cell 112 may not include a current collector. For example, when a metal foil such as a lithium foil is used as the negative electrode active material, some of the negative electrodes do not include a negative electrode current collector.

[0172] In this embodiment, the details of the method for producing the storage cell 112 have been described by taking as an example a case in which the lead 1242 is connected to each of the connection regions 566 of the two negative electrodes 240. However, the storage cell 112 is not limited to this embodiment. In other embodiments, the lead 1242 is connected to the connection region 566 of at least one of the two negative electrodes 240.

[0173] The lead 1222 may be an example of one of the first terminal and the second terminal for electrically connecting an external device and the second current collector. The lead 1242 may be an example of the other of the first terminal and the second terminal. The storage battery 110 may be an example of an external device. A charging device that charges the storage battery 110 may be an example of an external device. The power control circuit 120 may be an example of an external device. The electric motor 130 may be an example of an external device. The sensor 150 may be an example of an external device. The control device 160 may be an example of an external device.

[0174] FIG. 13 is a schematic diagram showing an example of the upper surface of the energy storage cell 112. As shown in FIG. 13, in this embodiment, the lead 1222 is electrically connected to the connection region 566 of the conductive layer 440 of the positive electrode current collector 222 outside the integrated region 320. Specifically, the lead 1222 and the conductive layer 440 are welded at a welding point 1322. Similarly, the lead 1242 is electrically connected to the connection region 566 of the conductive layer 440 of the negative electrode current collector 242 outside the integrated region 320. Specifically, the lead 1242 and the conductive layer 440 are welded at a welding point 1342. According to this embodiment, the conductive layers 440 included in each of the two negative electrode current collectors 242 are electrically connected via a conductive member 952 disposed in the through hole 950.

[0175] FIG. 14 shows an example of a cross section of a power storage cell 1412. The power storage cell 1412 shows another example of the power storage cell 112. According to the present embodiment, the power storage cell 1412 differs from the power storage cell 112 in that two positive electrodes 220 and one negative electrode 240 are stacked with two separators 230 interposed therebetween. According to the present embodiment, the power storage cell 1412 also differs from the power storage cell 112 in that the negative electrode 240 does not have a negative electrode current collector 242. In this case, the negative electrode active material layer 244 may have a shape similar to that of the conductive layer 440 described in relation to FIGS. 4 to 10.

[0176] Except for the above differences, the power storage cell 1412 may have the same configuration as the power storage cell 112. As a result, in this embodiment, parts of the two positive electrode current collectors 222 arranged on the outermost sides of the power storage cell 1412 are integrated together, and a stack formed by stacking the positive electrode active material layer 224, the separator 230, the negative electrode active material layer 244, the separator 230, and the positive electrode active material layer 224 in this order is sealed inside the two positive electrode current collectors 222.

[0177] (An example of another embodiment) In the present embodiment, the details of the storage cell 1412 have been described by taking as an example a case in which two positive electrodes 220 and one negative electrode 240 are stacked with two separators 230 interposed therebetween. However, the storage cell 1412 is not limited to this embodiment. In other embodiments, the storage cell 112 may be arranged such that the positive electrode active material layer 224 and the negative electrode active material layer 244 face each other with the separator 230 interposed therebetween, and the numbers of the positive electrodes 220 and the negative electrodes 240 are not particularly limited.

[0178] According to another example of the storage cell 1412, (i) the storage cell 1412 includes a laminate in which one positive electrode 220 and two negative electrodes 240 are laminated with two separators 230 interposed therebetween, and (ii) the two negative electrode current collectors 242 arranged on the outermost sides of the storage cell 1412 are partially integrated together, thereby sealing the laminate inside the two negative electrode current collectors 242. In this case, the positive electrode 220 may or may not have a positive electrode current collector 222.

[0179] FIG. 15 shows an example of a cross section of a storage cell 1512. The storage cell 1512 shows another example of the storage cell 112. According to the present embodiment, the storage cell 1512 differs from the storage cell 112 in that one of two current collectors arranged on the outermost side is a positive electrode current collector 222, and the other of the two current collectors is a negative electrode current collector 242. In the present embodiment, the details of the storage cell 1512 are described using as an example a case in which the electrode arranged on the outermost side of the storage cell 1512 includes a current collector, and the other electrodes do not include a current collector. However, the storage cell 1512 is not limited to the present embodiment. For example, except for the above differences, the storage cell 1512 may have a configuration similar to that of the storage cell 112 and / or the storage cell 1412.

[0180] As shown in FIG. 15, in this embodiment, the energy storage cell 1512 is produced by (i) stacking a positive electrode collector 222, a positive electrode active material layer 224, a separator 230, a negative electrode active material layer 244, a separator 230, a positive electrode active material layer 224, a separator 230, a negative electrode active material layer 244, and a negative electrode collector 242 in this order, and (ii) integrating a portion of the positive electrode collector 222 and the negative electrode collector 242 that are arranged on the outermost sides of the energy storage cell 1512. As a result, the laminate formed by stacking the positive electrode active material layer 224, the separator 230, the negative electrode active material layer 244, the separator 230, the positive electrode active material layer 224, the separator 230, and the negative electrode active material layer 244 in this order is sealed by the positive electrode current collector 222 and the negative electrode current collector 242.

[0181] 16 is a schematic diagram showing an example of the top surface of a power storage cell 1612. The power storage cell 1612 shows another example of the power storage cell 112. In this embodiment, the details of the power storage cell 1612 will be described by taking as an example a case in which the support layer of the current collector constituting each of the two outermost electrodes of the power storage cell 1612 has a rectangular shape, and the current collector constituting each of the one or more electrodes disposed between the two electrodes has a shape similar to that of the current collector 400 described above (i.e., an L-shape).

[0182] The current collectors constituting the two outermost electrodes of the power storage cell 1612 may have the same configuration as the current collector 400, the current collector 900, or the current collector 1000, except that the support layer 420 has a rectangular shape and that the conductive layer 440 does not have an opening 450. The current collectors constituting the electrodes other than those described above may have the same configuration as the current collector 400, the current collector 900, or the current collector 1000, except that the conductive layer 440 does not have an opening 450.

[0183] More specifically, the energy storage cell 1612 differs from the energy storage cell 112 in that the energy storage cell 1612 includes a plurality of positive electrodes 220 and a plurality of negative electrodes 240. In addition, the energy storage cell 1612 according to the present embodiment differs from the energy storage cell 112 in that the conductive layers 542 and 544 disposed in the connection region 566 set in the tab portion 564 of the conductive layer 440 of the positive electrode current collector 222 are electrically connected to the lead 1222 inside the integrated region 320. Similarly, the energy storage cell 1612 differs from the energy storage cell 112 in that the conductive layers 542 and 544 disposed in the connection region 566 set in the tab portion 564 of the conductive layer 440 of the negative electrode current collector 242 are electrically connected to the lead 1242 inside the integrated region 320.

[0184] In this embodiment, the lead 1222 does not have an opening 450 for exposing the support layer 420 of the positive electrode current collector 222. Therefore, when the integrated region 320 is integrated by welding, for example, the lead 1222 and the positive electrode current collector 222 cannot be integrated. Therefore, in this embodiment, the energy storage cell 1612 includes a seal member 1622 disposed between the lead 1222 and the positive electrode current collector 222. As the seal member 1622, a material known as a sealant for tabs is used.

[0185] The seal member 1622 is arranged to cover, for example, a portion of the lead 1222 corresponding to the integrated region 320. For example, in the connection region 566, when the lead 1222 is arranged in contact with the conductive layer 440 of the first positive electrode 220 and the conductive layer 440 of the second positive electrode 220, the support layer 420 of the first positive electrode 220, the lead 1222, the seal member 1622, and the support layer 420 of the second positive electrode 220 are laminated in this order in the integrated region 320. As a result, the integrated region 320 is welded, and the inside of the integrated region 320 is sealed. One of the first positive electrode 220 and the second positive electrode 220 may be the positive electrode 220 arranged on the outermost side among the multiple positive electrodes 220 constituting the storage cell 1612.

[0186] Similarly, for example, in the connection region 566, when the lead 1222 is disposed in contact with the conductive layer 440 of the first positive electrode 220 and the conductive layer 440 of the first negative electrode 240, the support layer 420 of the first positive electrode 220, the lead 1222, the seal member 1622, and the support layer 420 of the first negative electrode 240 are laminated in this order in the integrated region 320. As a result, the integrated region 320 is welded, thereby sealing the inside of the integrated region 320. One of the first positive electrode 220 and the first negative electrode 240 may be the electrode disposed on the outermost side among the multiple electrodes constituting the storage cell 1612.

[0187] Similarly, in this embodiment, the lead 1242 does not have an opening for exposing the support layer 420 of the negative electrode current collector 242. Therefore, when the integrated region 320 is integrated by welding, for example, the lead 1242 and the negative electrode current collector 242 cannot be integrated. Therefore, in this embodiment, the energy storage cell 1612 includes a seal member 1642 disposed between the lead 1242 and the negative electrode current collector 242. As the seal member 1642, a material known as a sealant for tabs is used.

[0188] The seal member 1642 is arranged to cover, for example, a portion of the lead 1242 corresponding to the integrated region 320. For example, when the lead 1242 is arranged in contact with the conductive layer 440 of the first negative electrode 240 and the conductive layer 440 of the second negative electrode 240 in the connection region 566, the support layer 420 of the first negative electrode 240, the lead 1242, the seal member 1642, and the support layer 420 of the second negative electrode 240 are laminated in this order in the integrated region 320. As a result, the integrated region 320 is welded, thereby sealing the inside of the integrated region 320. One of the first negative electrode 240 and the second negative electrode 240 may be the negative electrode 240 arranged on the outermost side among the multiple negative electrodes 240 constituting the storage cell 1612.

[0189] Similarly, for example, in the connection region 566, when the lead 1242 is disposed in contact with the conductive layer 440 of the first negative electrode 240 and the conductive layer 440 of the first positive electrode 220, the support layer 420 of the first negative electrode 240, the lead 1242, the seal member 1642, and the support layer 420 of the first positive electrode 220 are laminated in this order in the integrated region 320. As a result, the integrated region 320 is welded, thereby sealing the inside of the integrated region 320. One of the first negative electrode 240 and the first positive electrode 220 may be the electrode disposed on the outermost side among the multiple electrodes constituting the storage cell 1612.

[0190] Except for the above differences, the power storage cell 1612 may have a configuration similar to that of the power storage cell 112, the power storage cell 1412, and / or the power storage cell 1512. For example, in the power storage cell 1612, the positive electrode active material layer 224 and the negative electrode active material layer 244 may be arranged to face each other via the separator 230, and the number of positive electrodes 220 and negative electrodes 240 included in the power storage cell 1612 is not particularly limited. In addition, at least a part of one or more electrodes other than the two electrodes arranged on the outermost sides of the power storage cell 1612 may not include a current collector.

[0191] 17 is a schematic diagram showing an example of components constituting the power storage cell 1612. According to the present embodiment, the power storage cell 1612 includes a plurality of positive electrodes 220 and a plurality of negative electrodes 240. In the present embodiment, the positive electrodes 220 and the negative electrodes 240 are disposed on the outermost sides of the power storage cell 1612, for example.

[0192] The positive electrode 220 arranged on the outermost side of the storage cell 1612 (sometimes referred to as the outermost positive electrode 220) includes, for example, a support layer 420, a conductive layer 440 arranged on one side of the support layer 420, and a positive electrode active material layer 224 arranged on the conductive layer 440. As described above, in this embodiment, the support layer 420 of the positive electrode 220 arranged on the outermost side of the storage cell 1612 has, for example, a rectangular shape.

[0193] The positive electrodes 220 other than the outermost positive electrode 220 include, for example, a support layer 420, two conductive layers 440 arranged on each of both sides of the support layer 420, and two positive electrode active material layers 224 arranged on each of the two conductive layers 440. In this embodiment, the support layer 420 has, for example, an L-shape including a main body region 762 supporting the current collecting portion 562 and a protruding region 764 supporting a connection region 566 of a tab portion 564.

[0194] The negative electrode 240 (sometimes referred to as the outermost negative electrode 240) disposed on the outermost side of the storage cell 1612 includes, for example, a support layer 420, a conductive layer 440 disposed on one side of the support layer 420, and a negative electrode active material layer 244 disposed on the conductive layer 440. As described above, in this embodiment, the support layer 420 of the negative electrode 240 disposed on the outermost side of the storage cell 1612 has, for example, a rectangular shape.

[0195] The negative electrodes 240 other than the outermost negative electrode 240 include, for example, a support layer 420, two conductive layers 440 disposed on each of both sides of the support layer 420, and two negative electrode active material layers 244 disposed on each of the two conductive layers 440. In this embodiment, the support layer 420 has, for example, an L-shape including a main body region 762 supporting the current collecting portion 562 and a protruding region 764 supporting a connection region 566 of a tab portion 564.

[0196] According to this embodiment, a lead 1222 is disposed in a connection region 566 of a conductive layer 440 of a positive electrode 220 (which may be collectively referred to as a second layer positive electrode 220) adjacent to the outermost layer negative electrode 240 via a separator 230. In addition, a sealing member 1622 is disposed so as to cover a portion of the lead 1222 corresponding to the integrated region 320. As a result, in the integrated region 320, the support layer 420 of the second layer positive electrode 220, the lead 1222, the sealing member 1622, and the support layer 420 of the outermost layer negative electrode 240 are laminated in this order as a whole.

[0197] According to this embodiment, the lead 1242 is disposed in the connection region 566 of the conductive layer 440 of the negative electrode 240 (which may be referred to as the third layer negative electrode 240 as a whole) adjacent to the second layer positive electrode 220 via the separator 230. In addition, the seal member 1642 is disposed so as to cover a portion of the lead 1242 corresponding to the integrated region 320. As a result, in the integrated region 320, the support layer 420 of the third layer negative electrode 240 as a whole, the lead 1242, the seal member 1642, and the support layer 420 of the outermost layer negative electrode 240 are laminated in this order.

[0198] In this embodiment, a plurality of positive electrodes 220 and a plurality of negative electrodes 240 are arranged such that the positive electrode active material layer 224 and the negative electrode active material layer 244 face each other. A separator 230 is arranged between the positive electrode active material layer 224 and the negative electrode active material layer 244. This produces a laminate in which the positive electrodes 220 and the negative electrodes 240 are alternately stacked with the separator 230 interposed therebetween.

[0199] According to this embodiment, first, one or more positive electrodes 220 (the above-described L-shaped positive electrodes 220) other than the outermost positive electrode 220 and one or more negative electrodes 240 (the above-described L-shaped negative electrodes 240) other than the outermost negative electrode 240 are alternately stacked with one or more separators 230 interposed therebetween. This produces a stack that does not include the outermost positive electrode 220 and the outermost negative electrode 240.

[0200] Next, in the connection region 566 of the one or more positive electrodes 220, the lead 1222 and the conductive layer 440 of the tab portion 564 of the one or more positive electrodes 220 are integrated by welding. Similarly, in the connection region 566 of the one or more negative electrodes 240, the lead 1242 and the conductive layer 440 of the tab portion 564 of the one or more negative electrodes 240 are integrated by welding. As the welding method and welding procedure, any known method and procedure may be adopted.

[0201] Next, a separator 230 and an outermost positive electrode 220 are disposed on one side of the laminate. A separator 230 and an outermost negative electrode 240 are disposed on the other side of the laminate. As described above, the outermost positive electrode 220 and the outermost negative electrode 240 have a rectangular shape. Then, the integrated region 320 of the laminate including the outermost positive electrode 220 and the outermost negative electrode 240 is integrated. For example, the integrated region 320 of the laminate is heated. As a result, the integrated region 320 of the positive electrode current collector 222 of the positive electrode 220 included in the laminate and the integrated region 320 of the negative electrode current collector 242 of the negative electrode 240 included in the laminate are integrated by welding. By the above procedure, the storage cell 1612 is manufactured.

[0202] (An example of another embodiment) In this embodiment, the details of the storage cell 1612 have been described assuming that the support layer 420 of the outermost positive electrode 220 and the support layer 420 of the outermost negative electrode 240 have a rectangular shape. However, the storage cell 1612 is not limited to this embodiment. The shape of each of the support layers 420 of the multiple positive electrodes 220 and the shape of each of the support layers 420 of the multiple negative electrodes 240 can be arbitrarily determined within a range in which the inside of the integrated region 320 can be sealed when the integrated region 320 is integrated. In another embodiment, the support layer 420 of the top electrode may have the above-described L-shaped shape, and the support layer 420 of the second electrode from the top as a whole may have a rectangular shape. Similarly, the support layer 420 of the bottom electrode may have the above-described L-shaped shape, and the support layer 420 of the second electrode from the bottom as a whole may have a rectangular shape.

[0203] Fig. 18 shows another example of components constituting a storage cell 1612. In this embodiment, the support layer 420 included in the electrode arranged on the outermost side of the storage cell 1612 has a main body region 762 and a protruding region 764, and differs from the storage cell 1612 described in relation to Fig. 17 in that the support layer 420 included in the electrode other than the above does not have the protruding region 764. The storage cell 1612 described in relation to Fig. 18 may have a similar configuration to the storage cell 1612 described in relation to Fig. 17 except for the above differences.

[0204] (An example of another embodiment) In this embodiment, the details of another example of the storage cell 1612 have been described by taking as an example a case where the integrated region 320 of each of the support layers 420 of the two electrodes in the outermost layer is welded to seal the inside of the integrated region 320. However, the other example of the storage cell 1612 is not limited to this embodiment. In another embodiment, the support layer 420 of each of the one or more electrodes disposed between the two electrodes in the outermost layer may have any shape. Depending on the shape of the support layer 420, a part of the one or more electrodes disposed between the two electrodes in the outermost layer may be welded together with the support layer 420 of each of the two electrodes in the outermost layer when the integrated region 320 of each of the support layers 420 of the two electrodes in the outermost layer is welded.

[0205] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the claims that such modifications and improvements can also be included in the technical scope of the present invention.

[0206] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before" or "prior to," and that the process may be performed in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," and the like for convenience, this does not mean that the process must be performed in this order. [Explanation of symbols]

[0207] 100 aircraft, 110 storage battery, 112 storage cell, 120 power control circuit, 130 motor, 140 propeller, 150 sensor, 160 control device, 202 terminal, 204 terminal, 206 exterior, 212 laminate, 214 electrolyte, 220 positive electrode, 222 positive electrode current collector, 224 positive electrode active material layer, 230 separator, 240 negative electrode, 242 negative electrode current collector, 244 negative electrode active material layer, 320 integrated region, 400 current collector, 420 support layer, 422 peripheral portion, 440 conductive layer, 450 opening, 522 first plane, 524 second plane, 526 side, 542 conductive layer, 544 conductive layer, 550 opening, 562 current collector, 564 Tab portion, 566 connection region, 568 exposed region, 762 main body region, 764 protruding region, 840 active material region, 900 current collector, 950 through hole, 952 conductive member, 1000 current collector, 1222 lead, 1242 lead, 1322 welded portion, 1342 welded portion, 1412 storage cell, 1512 storage cell, 1612 storage cell, 1622 sealing member, 1642 sealing member

Claims

1. A support layer including a resin material; a conductive layer formed on at least one surface of the support layer and having a higher electrical conductivity than the support layer; Equipped with an exposed portion is formed in the conductive layer, the exposed portion penetrating the conductive layer and exposing a part of the support layer without penetrating the support layer; Current collector.

2. The support layer includes a thermoplastic resin material. The current collector according to claim 1 .

3. The conductive layer is A main body portion, an extension portion extending from a portion of the main body portion toward an outside of the main body portion; having The exposed portion is disposed near the boundary between the main body portion and the extension portion. The current collector according to claim 1 .

4. At least a portion of the exposed portion is disposed inside the extension portion. The current collector according to claim 3 .

5. The conductive layer has a plurality of exposed portions formed therein, At least a portion of the plurality of exposed portions is disposed on at least a portion of a periphery of the conductive layer. The current collector according to claim 1 .

6. The conductive layer is A main body portion, an extension portion extending from a portion of the main body portion toward an outside of the main body portion; having A plurality of the exposed portions are formed on the main body portion. The current collector according to claim 1 .

7. The conductive layer is a first conductive layer formed on a first surface of the support layer; a second conductive layer formed on a second surface of the support layer; having The current collector has a through hole penetrating the first conductive layer, the support layer, and the second conductive layer. The current collector according to claim 1 .

8. Each of the first conductive layer and the second conductive layer is A main body portion, an extension portion extending from a portion of the main body portion toward an outside of the main body portion; having the through hole penetrates a part of the extending portion of the first conductive layer, a part of the support layer, and a part of the extending portion of the second conductive layer; The current collector according to claim 7.

9. a connection member disposed inside the through hole and electrically connecting the first conductive layer and the second conductive layer; The current collector according to claim 7.

10. The conductive layer has one or more exposed portions formed therein, The current collector has one or more through holes formed therein, an average value of the equivalent circle diameter of the one or more exposed portions is different from an average value of the equivalent circle diameter of the one or more exposed portions; The current collector according to claim 7.

11. A current collector according to any one of claims 1 to 10, an active material layer disposed on at least one surface of the current collector; Equipped with electrode.

12. A positive electrode and A negative electrode; a separator disposed between the positive electrode and the negative electrode; Equipped with The positive electrode is A current collector according to any one of claims 1 to 10, a positive electrode active material layer disposed on at least one surface of the current collector; having The negative electrode is A current collector according to any one of claims 1 to 10, a negative electrode active material layer disposed on at least one surface of the current collector; having battery.

13. A battery according to claim 12; a thrust generating device that generates thrust by utilizing the electric energy stored in the battery; An aircraft equipped with

14. A first electrode; A second electrode; a separator disposed between the first electrode and the second electrode; Equipped with The first electrode is A first current collector; a first active material layer disposed on at least one surface of the first current collector; having The second electrode is A second current collector; a second active material layer disposed on at least one surface of the second current collector; having Each of the first current collector and the second current collector is A support layer including a resin material; a conductive layer formed on at least one surface of the support layer and having a higher electrical conductivity than the support layer; Including, the resin material contained in at least a portion of a peripheral portion of the support layer of the first current collector and the resin material contained in at least a portion of a peripheral portion of the support layer of the second current collector are integrated together so as to seal the first active material layer, the separator, and the second active material layer by the first current collector and the second current collector. battery.

15. the battery further includes a first terminal for electrically connecting an external device to the first current collector; the first terminal is electrically connected to the conductive layer of the first current collector outside a region where the resin material of the first current collector and the resin material of the second current collector are integrated together; 15. The battery of claim 14.

16. the battery further includes a first terminal for electrically connecting an external device to the first current collector; the first terminal is electrically connected to the conductive layer of the first current collector inside a region where the resin material of the first current collector and the resin material of the second current collector are integrated together; 15. The battery of claim 14.

17. A battery according to claim 14; a thrust generating device that generates thrust by utilizing the electric energy stored in the battery; An aircraft equipped with

18. a conductive layer forming step of forming a conductive layer containing a conductive material having a higher conductivity than the resin material on at least one surface of a support layer containing a resin material, The conductive layer forming step includes a disposing step of disposing the conductive material on the at least one surface of the support layer so as to form a conductive layer having an exposed portion that penetrates the conductive layer and exposes a portion of the support layer without penetrating the support layer. A method for producing a current collector.

19. Providing a current collector; an active material layer forming step of forming an active material layer containing an active material on at least one surface of the current collector; having The current collector is A support layer including a resin material; a conductive layer formed on at least one surface of the support layer and having a higher electrical conductivity than the support layer; Equipped with an exposed portion is formed in the conductive layer, the exposed portion penetrating the conductive layer and exposing a portion of the support layer without penetrating the support layer; The conductive layer is A body member; an extension member extending from a portion of the body member toward an exterior of the body member; having The step of forming an active material layer includes a step of forming an active material layer on at least a portion of the body member of the conductive layer. A method for producing an electrode.

20. a lamination step of laminating a first electrode, a separator, and a second electrode in this order; a integrating step of integrating at least a portion of a periphery of the first electrode with at least a portion of a periphery of the second electrode; having The first electrode is A first current collector; a first active material layer disposed on at least one surface of the first current collector; having The second electrode is A second current collector; a second active material layer disposed on at least one surface of the second current collector; having Each of the first current collector and the second current collector is A support layer including a resin material; a conductive layer formed on at least one surface of the support layer and having a higher electrical conductivity than the support layer; Including, the integrating step includes a sealing step of integrating the resin material contained in at least a portion of the peripheral portion of the support layer of the first current collector with the resin material contained in at least a portion of the peripheral portion of the support layer of the second current collector to seal the first active material layer, the separator, and the second active material layer. A method for producing batteries.

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