Method for producing rechargeable battery

Abstract

According to one aspect of the present invention, a rechargeable battery is produced by not utilizing lithium metal foil, but utilizing a negative electrode on which a charging process for pre-doping has been carried out. A pre-doping electrode is prepared, and before the charging process is performed, an outer casing is sealed. After the charging process for pre-doping has ended, a portion of the outer casing is cut off, the pre-doping electrode is drawn out, and the outer casing is resealed, thereby producing a rechargeable battery. When pulling out the pre-doping electrode, an end part of the electrode film is pulled nimbly and smoothly.

Description

Method for manufacturing secondary batteries

[0001] The present invention relates to a secondary battery or a method for manufacturing the same.

[0002] In recent years, there has been active development of various types of energy storage devices, such as lithium-ion secondary batteries, lithium-ion capacitors, air batteries, and all-solid-state batteries. Demand for high-power, high-capacity lithium-ion secondary batteries has expanded rapidly in line with the development of the semiconductor industry, and they have become indispensable in today's information society as a rechargeable energy source.

[0003] As the electrode material for lithium-ion secondary batteries, a material capable of inserting and extracting lithium is preferred, and examples thereof include carbon-based materials such as graphite, and alloy-based materials such as silicon or silicon oxide. Among alloy-based materials, the theoretical capacity of silicon is about 10 times higher than that of graphite, and silicon-based active materials are considered promising as host materials for lithium.

[0004] However, even in lithium ion secondary batteries that use a carbon-based material such as graphite or an alloy-based material such as silicon as the negative electrode active material, the positive electrode material LiFePO ４ , LiCoO ２ , LiMn ２ O ４ It is extremely difficult to remove all of the lithium introduced into the alloy-based material of the negative electrode active material by discharging, and a certain amount of lithium remains in the alloy-based material. In other words, irreversible lithium capacity is generated, resulting in a decrease in the discharge capacity of the secondary battery and a decrease in battery performance.

[0005] In particular, when silicon is used as the active material, the inherent high capacity of silicon anodes is sacrificed by limiting the usable potential range. Furthermore, the conventional contact doping method has the problem of lithium remaining on the anode surface. Furthermore, there are other problems, such as the complicated manufacturing process of lithium-ion secondary batteries.

[0006] Patent Document 1 discloses a method for manufacturing a lithium ion secondary battery having a positive electrode containing a positive electrode active material capable of inserting and desorbing lithium, a negative electrode containing a negative electrode active material capable of inserting and desorbing lithium, and an electrolyte, characterized in that lithium is inserted into the negative electrode before assembling the battery, and after the insertion, part of the lithium inserted into the negative electrode is desorbed, and after the desorption, the battery is assembled.

[0007] JP 2013-69418 A

[0008] In Patent Document 1, an aging cell is prepared using lithium metal foil, and after aging, the aging cell is disassembled, the negative electrode is removed, and a new cell is assembled. Because of the disassembly, the cell components and electrolyte must be discarded, resulting in waste of materials. While this method could be used to prepare small coin cells, it was difficult to fabricate large-capacity secondary batteries, such as laminated cells.

[0009] In addition, since lithium metal foil is difficult to handle, a manufacturing method that performs aging treatment for pre-doping without using lithium metal foil is desired. One of the objects of the present invention is to provide a manufacturing method for a practical secondary battery.

[0010] Another object of the present invention is to provide a method for manufacturing a lithium ion secondary battery that can effectively extract the actual capacity of the secondary battery by using a negative electrode that has been subjected to aging treatment for pre-doping.

[0011] Therefore, when fabricating a laminated cell, a secondary battery is fabricated using an exterior body that undergoes aging treatment (charging) for pre-doping. The positive electrode, pre-doping electrode, and negative electrode are stacked and housed in a bag-shaped exterior body. Leads are connected to each before sealing. The exterior body is sealed before charging treatment, but after the charging treatment for pre-doping is completed, part of the exterior body is cut, the pre-doping electrode is removed, and the cell is re-sealed to complete the pre-doping process.

[0012] The electrolyte is maintained before and after cutting a portion of the exterior body, so that unnecessary leakage of the electrolyte is prevented even when removing the pre-doping electrode. The pre-doping electrode is wrapped in a separator film, and the pre-doping electrode can be smoothly removed by pulling a portion of the separator film.

[0013] When removing the pre-doping electrode, it must be removed without shifting the position of the adjacent negative or positive electrode. If the position is shifted within the bag-shaped outer packaging, there will be areas where the positive and negative electrodes do not overlap when the electrode is resealed, causing the charge to be unevenly distributed, resulting in uneven reactions and variations in characteristics, making it impossible to obtain the desired capacity with a good yield. Therefore, it is important to grasp the separator film surrounding the pre-doping electrode to make it easier to remove it and to avoid shifting the positions of the positive and negative electrodes when removing it. To make it easier to grasp the separator film, the separator film surrounding the pre-doping electrode is overlapped with the negative electrode, or the separator film surrounding the pre-doping electrode is made extra large to provide a gripping margin.

[0014] The method for producing a secondary battery disclosed in this specification includes storing a positive electrode wrapped in a first film, an electrode wrapped in a second film, and a negative electrode having a negative electrode active material in a bag-shaped outer casing, pouring an electrolyte into the bag-shaped outer casing, sealing the bag-shaped outer casing, the electrode having a first lead and a first terminal connected to the first lead, the negative electrode having a second lead and a second terminal connected to the second lead, performing a charging process in which current is passed through the first terminal and the second terminal to perform a pre-doping process, cutting a portion of the bag-shaped outer casing, pulling an end of the second film to remove the electrode, and resealing the outer casing.

[0015] In the above configuration, the positive electrode is a positive electrode current collector on which a first positive electrode active material layer is formed, and a third lead is connected to the tab portion of the positive electrode current collector before the bag-shaped outer casing is sealed; the electrode is a current collector on which a second positive electrode active material layer is formed, and a first lead is connected to the tab portion of the current collector before the bag-shaped outer casing is sealed; and the negative electrode is a negative electrode current collector on which a negative electrode active material layer is formed, and a second lead is connected to the tab portion of the negative electrode current collector before the bag-shaped outer casing is sealed.

[0016] In the above configuration, before the bag-shaped outer casing is sealed, the first film and the second film are stacked in contact with each other inside the bag-shaped outer casing, the area of ​​the first film is larger than that of the second film, and when removing the electrode, the end of the first film that does not overlap with the second film is pulled.

[0017] In the above configuration, the pre-doping electrode may be removed, and a positive electrode and a negative electrode may be combined into a set. A plurality of sets may be housed in an exterior body, thereby increasing the capacity.

[0018] In this specification, the charging process for pre-doping (pre-doping process) is not limited to doping of lithium ions into the negative electrode active material, but refers to the application of current to add lithium ions to the secondary battery in order to replenish the lithium ions that have been consumed and reduced due to film formation or side reactions during the initial charge, and to obtain the designed capacity.

[0019] In addition, it is preferable to appropriately adjust the charging conditions for pre-doping so that the capacity of the secondary battery produced after pre-doping is maximized. It is preferable to set the charging conditions for pre-doping so that the total capacity that can be inserted into the negative electrode is at least about 30% after pre-doping. In this way, it is necessary to adjust the doping amount of lithium ions into the negative electrode, and the charging process for pre-doping is performed according to the size or capacity of the secondary battery.

[0020] In addition, the pre-doping electrode can be made of the same material and in the same process as the positive electrode, without using a lithium metal foil. If the pre-doping electrode has the same structure as the positive electrode, it is easy to adjust the amount of lithium ions doped into the negative electrode.

[0021] Furthermore, in the above configuration, when the bag-shaped exterior body is sealed, the positive electrode lead, the negative electrode lead, and the electrode leads do not overlap.

[0022] In addition, in the above configuration, it is preferable that the series of processes from cutting a portion of the outer casing, removing the electrode, and resealing the outer casing be carried out in a short time and in a glove box or in a dry atmosphere so as to prevent the solvent from volatilizing as much as possible.

[0023] According to the method of the present invention, a charging process for pre-doping can be carried out without using a lithium metal foil, and a laminate-type secondary battery can be produced.

[0024] FIG. 1 is a diagram showing an example of a production flow of a secondary battery showing one embodiment of the present invention. FIGS. 2A1 and 2A2 are perspective views of a positive electrode, 2A3 is a cross-sectional view of the positive electrode, 2B1 and 2B2 are perspective views of a pre-doping electrode, and 2B3 is a cross-sectional view of the pre-doping electrode. FIG. 3A1 is a perspective view of a positive electrode, 3A2 is a perspective view of a pre-doping electrode, 3A3 is a perspective view of a negative electrode, and 3B is a perspective view of a laminate and an outer casing. FIG. 4A is a side view of a liquid injection process, 4B is a top view of a secondary battery cell, and 4C is a cross-sectional view of a secondary battery cell. FIG. 5A is a side view showing the outer casing during cutting, and FIG. 5B is a side view immediately after the pre-doping electrode has been pulled out. FIG. 6A is a perspective view of a secondary battery, and FIG. 6B is a cross-sectional view of a secondary battery. FIG. 7A is a top view of a film, and FIG. 7B is a top view of a film that will become the outer casing 23. FIG. 8A is an example of a cross-sectional view of a secondary battery, and FIG. 8B is a partially enlarged view of the secondary battery. FIGS. 9A and 9B are perspective views of a bent secondary battery 10. FIG. 10 is a top view of a secondary battery in the process of fabrication. FIGS. 11A to 11D are diagrams illustrating a transportation vehicle according to one embodiment of the present invention. FIGS. 12A to 12C are diagrams illustrating a two-wheeled vehicle according to one embodiment of the present invention. FIGS. 13A to 13D are diagrams illustrating electronic devices according to one embodiment of the present invention. FIGS. 14A to 14D are diagrams illustrating an example of space equipment.

[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various modifications can be made to the embodiments and details. Furthermore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0026] Embodiment 1 In this embodiment, a method for manufacturing a laminate secondary battery according to one embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a flowchart illustrating an example of a method for manufacturing a laminate secondary battery.

[0027] First, prepare a positive electrode 503, a negative electrode 506, and a pre-doping electrode 513. In this embodiment, an example of a secondary battery in which a single-sided coated positive electrode or negative electrode is used and a set of the positive electrode 503 and the negative electrode 506 is enclosed in an exterior body 509 is shown, but this is not particularly limited, and a process in which a double-sided coated positive electrode or negative electrode is used and a plurality of sets are enclosed in a single exterior body can also be used.

[0028] The positive electrode 503 and the pre-doping electrode 513 can be formed by coating one side of a positive electrode active material layer on a current collector and then processing it into the desired shape. As shown in FIG. 1 , the pre-doping electrode 513 can be formed in step S21, and the positive electrode 503 can be formed separately in step S31. However, if the same material and size are used, the same process can be used. The current collectors used for the positive electrode 503 and the pre-doping electrode 513 can be made of highly conductive materials such as metals such as stainless steel, gold, platinum, aluminum, and titanium, and alloys thereof. Furthermore, when a current collector is used for the positive electrode 503, it is preferable that the current collector does not dissolve at the potential of the positive electrode 503. Furthermore, aluminum alloys containing elements that improve heat resistance, such as silicon, titanium, neodymium, scandium, and molybdenum, can be used. The current collector can be in the form of a foil, plate (sheet), mesh, punched metal, expanded metal, or the like, as appropriate. The current collector has a thickness of 5 μm to 30 μm.

[0029] The positive electrode active material layer may be made of a known positive electrode active material, such as a composite oxide having an olivine-type crystal structure, a layered rock salt-type crystal structure, or a spinel-type crystal structure.

[0030] The positive electrode active material is not particularly limited as long as it is a lithium oxide, and lithium cobalt oxide (LiCoO ２ : also called LCO), lithium iron phosphate (LiFePO ４ : also called LFP), lithium nickel oxide (LiNiO ２ ), lithium manganese oxide (LiMn ２ O ４ ), lithium manganese phosphate (LiMnPO ４ ), lithium manganese iron phosphate (LiFeａ Mn ｂ P.O. ４ a+b is 1 or less, 0<a<1, 0<b<1), any one or more of which can be used.

[0031] In addition, when the carrier ions are alkali metal ions or alkaline earth metal ions other than lithium ions, an alkali metal (e.g., sodium or potassium) or an alkaline earth metal (e.g., calcium, strontium, barium, beryllium, or magnesium) may be used as the positive electrode active material instead of lithium.

[0032] The thickness of the positive electrode active material layer is determined by the viscosity or components of the slurry applied to the positive electrode current collector 501 or the film-forming conditions of the application device. To prepare the slurry, a positive electrode active material, a binder, a solvent, and a conductive additive are mixed. Polyvinylidene fluoride (PVDF) is used as the binder, N-methyl-2-pyrrolidone (NMP) is used as the solvent, and acetylene black is used as the conductive additive. The thickness of the positive electrode active material layer also varies depending on the heating conditions or pressing conditions after application.

[0033] Then, a first film is provided so as to encase the positive electrode 503. The first film is processed into a bag shape and fixed with tape or the like. This stage is shown in FIGS. 2A2 and 2A3. FIG. 2A3 is a cross-sectional view of the positive electrode taken along the chain line X1-X2 in FIG. 2A2. In FIGS. 2A1 and 2A2, a positive electrode active material layer is formed on the lower surface of the positive electrode current collector 501, and is therefore not shown.

[0034] 2A1 and 2A2 show perspective views of the positive electrode current collector 501 and the separator 507. A single first film that will become the separator 507 is folded, and the end of the first film is fixed as an adhesive region 514a, with the tab portion of the positive electrode current collector 501 protruding from the first film, resulting in the state shown in FIG. 2A2. The separator 507 refers to the region sandwiched between the positive electrode and the negative electrode, and is part of the first film. While FIG. 2A2 shows an example in which the separator 507 is fixed as an adhesive region 514a on two sides, it may also be fixed by providing adhesive regions on four sides.

[0035] Each current collector is provided with a protruding region (also called a tab portion or tab region) for connection to a lead electrode, and the region is not provided with a positive electrode active material layer or the like, so that the conductive surface is exposed.

[0036] The pre-doping electrode 513 is also wrapped in a second film in the same manner as the positive electrode. FIGS. 2B1 and 2B2 show perspective views of the pre-doping electrode 513 and the second film 517. As shown in FIG. 2B1, the pre-doping electrode 513 is formed by folding a single second film, fixing the end of the second film as an adhesive region 514b, and causing the tab portion of the pre-doping electrode 513 to protrude from the second film, resulting in the state shown in FIG. 2B2. The cross-sectional view taken along the dashed line X3-X4 in FIG. 2B2 corresponds to FIG. 2B3. For the subsequent extraction process, the second film has a larger area than the first film of the positive electrode, and a margin region 517m is provided. The margin region 517m can also be considered a gripping margin.

[0037] Furthermore, it is preferable that the negative electrode current collector 504 used for the negative electrode 506 does not form an alloy with carrier ions such as lithium. Specifically, copper or a copper alloy is used as the material for the negative electrode current collector 504. Furthermore, as shown in step S11, a negative electrode active material layer is formed by coating one side of the negative electrode current collector 504. Then, a lead electrode is ultrasonically bonded to the tab portion of the negative electrode current collector 504 on which the negative electrode active material layer is not formed.

[0038] The negative electrode active material is a mixture of carbon particles and a silicon-based material. Silicon has a theoretical capacity of 4,200 mAh / g, more than 10 times that of graphite (372 mAh / g). However, a negative electrode using only silicon suffers from rapid cycle degradation due to expansion and contraction during charging and discharging. To improve cycle degradation, nanosilicon, which is made by miniaturizing silicon particles, is preferably used. Furthermore, the negative electrode active material is not limited to the above materials, and this embodiment is also effective when using materials with large irreversible capacity, such as hard carbon or tin.

[0039] The binder used in the negative electrode is a polymer compound having a carboxy group, specifically a polymer having polyacrylic acid.

[0040] As the carbon particles, graphite, carbon having a layer structure like graphite, amorphous carbon, or hard carbon may be used. Carbon fibers may also be used instead of carbon particles. The carbon particles used in this specification specifically refer to graphite particles, which are abundant in nature and therefore inexpensive, making them preferable as an active material for a negative electrode.

[0041] In the above configuration, the silicon particles refer to silicon powder used as a negative electrode active material for lithium-ion secondary batteries, and refer to those with an average particle diameter of approximately 100 nm, sometimes referred to as nanosilicon particles. The silicon particles used are preferably prepared by pulverizing silicon raw materials to adjust the particle diameter to a uniform size. The silicon particles include at least one of silicon, silicon oxide, and silicon alloy.

[0042] Furthermore, a conductive additive may be added when forming the negative electrode active material layer. A typical example of a carbon material used as a conductive additive is acetylene black (also referred to as AB). Acetylene black is a bulky particle with an average particle diameter of several tens to several hundreds of nanometers, making it difficult to bring it into surface contact with other materials, and point contact is likely to occur. Therefore, when an active material is mixed with acetylene black, the contact resistance between the active material and acetylene black increases. If a large amount of acetylene black is used to reduce the contact resistance, the ratio of the active material to the entire electrode decreases, resulting in a decrease in the discharge capacity of the secondary battery.

[0043] Acetylene black is a material that tends to aggregate, so it is preferable to mix it so that it is uniformly dispersed. The weight ratio of acetylene black is less than or equal to the weight ratio of silicon particles. Of course, secondary batteries can be manufactured without adding the conductive additive (acetylene black).

[0044] Through the above steps, a positive electrode wrapped in the first film, a pre-doping electrode 513 wrapped in the second film, and a negative electrode can be prepared.

[0045] Next, the positive electrode lead electrode 510 is joined to the tab portion of the positive electrode, the negative electrode lead electrode 511 is joined to the tab portion of the negative electrode, and the pre-doping lead electrode 518 is joined to the tab portion of the pre-doping electrode by ultrasonic bonding. The negative electrode current collector 504, the pre-doping lead electrode 518, and the positive electrode current collector 501 are stacked in this order, and the centers of the electrodes are aligned and positioned. While fixed in position with tape, the periphery is thermocompressed using a heat bar sealer so that it is sandwiched between laminate films that will become the exterior body.

[0046] Note that Figure 3A1 shows an oblique view before connecting the positive electrode lead electrode 510, Figure 3A2 shows an oblique view before connecting the pre-doping lead electrode 518, and Figure 3A3 shows an oblique view before connecting the negative electrode lead electrode 511, and the dotted lines in the figures are aligned so that they overlap.

[0047] 3B shows a perspective view of one laminate film that forms the exterior before folding. The negative electrode has a larger area than the positive electrode, and they are stacked with their centers aligned, with their respective edges almost, but not perfectly, aligned. As shown in FIG. 3B, the edges of the positive electrode, pre-doping electrode, and negative electrode are stacked so that they almost align, while the edge of the second film 517 is designed to have a larger area than the first film so that it can be gripped.

[0048] When the periphery is thermocompressed using a heat bar sealer, the thermocompression is performed leaving one side for later filling with an electrolyte. After thermocompression, the separator film becomes a bag-shaped exterior body 509, and the positive electrode, the pre-doping electrode, and the negative electrode are arranged inside. As shown in step S101, the electrodes are overlapped and aligned inside (step S102), and the state sealed with the bag-shaped exterior body 509 is also called three-sided sealing.

[0049] Then, the bag-shaped exterior body 509 is fixed with the part where the electrolyte is to be poured facing up, and the electrolyte 508 is poured in an argon gas atmosphere (step S102).

[0050] 4A shows a side view of the injection process of electrolyte solution 508. Exterior body 509 is fixed in place by first pressure-bonding region 509a. The portion of a single laminate film folded to form one side does not need to be pressure-bonded, but is pressure-bonded in this embodiment. First pressure-bonding region 509a, which overlaps with the folded portion of the laminate film, functions as a guide for aligning the exterior body and the laminate, thereby preventing misalignment of the overlapping electrodes.

[0051] After the injection of the electrolyte solution 508 is completed, a vacuum sealing process (step S103) is performed.

[0052] The reduced pressure sealing is a sealing process performed in a reduced pressure environment, and the reduced pressure environment is preferably 50,000 Pa or less, and more preferably 40,000 Pa or less, 30,000 Pa or less, 20,000 Pa or less, 10,000 Pa or less, 5,000 Pa or less, or 1,000 Pa or less. Depending on the type of electrolytic solution 508 used, excessive reduction in pressure may cause volatilization, so the reduced pressure value is adjusted depending on the electrolytic solution 508 used.

[0053] After the injection of the electrolyte solution, an impregnation treatment may be performed to facilitate impregnation of the pores of the electrodes and the separator with the electrolyte solution. As the impregnation treatment, a decompression treatment (also referred to as a vacuuming treatment) is preferably performed, and the decompression treatment and the pressure recovery treatment may be performed multiple times.

[0054] The environmental pressure in the decompression treatment is preferably a gauge pressure of −60 kPa. The exterior body can be sealed at the same environmental pressure as the decompression treatment described above, or at an environmental pressure different from that of the decompression treatment described above.

[0055] During the reduced pressure sealing shown in step S103, a second thermocompression bonding is performed, and temporary compression bonding area 509e is provided to close the opening of bag-shaped exterior body 509. Thereafter, excess laminate film is cut off.

[0056] A secondary battery cell having a pre-doping electrode is fabricated through the above steps, and Fig. 4B shows a top view of the secondary battery cell. Fig. 4C is a cross-sectional view taken along the chain line X5-X6 in Fig. 4B.

[0057] As shown in Fig. 4C, an electrolyte solution 508 is sealed inside an exterior body 509, and a laminate is arranged therein. The laminate arranged inside the exterior body 509 is formed by laminating a negative electrode 506, a pre-doping electrode, and a positive electrode in this order. The positive electrode has a positive electrode active material layer 502 formed on a positive electrode current collector 501, and is wrapped with a separator 507, which is a first film. The pre-doping electrode has a pre-doping active material layer 512 formed on a pre-doping electrode 513, and is wrapped with a second film 517. The negative electrode 506 has a negative electrode active material layer 505 formed on a negative electrode current collector 504.

[0058] Then, in step S104, a charging process for pre-doping (also referred to as a pre-doping process) is performed. As a charging process for pre-doping, charging is performed to 10% to 40% of the capacity, preferably 30%, under the condition of a constant voltage of -0.2V. The 30% capacity is calculated in advance based on an estimated value of the capacity of the secondary battery to be finally produced, and the charge amount is appropriately determined, taking into account the material and weight of the positive electrode active material layer and the configuration of the negative electrode. In this embodiment, nanosilicon is mixed at a smaller rate than the graphite used as the configuration of the negative electrode, specifically, the weight ratio is graphite: nanosilicon: AB: polyacrylic acid = 72: 8: 6: 14, and 30% of the capacity is the optimal value.

[0059] During charging, an external power source is connected to the pre-doping lead electrode 518, and an external power source is connected to the negative electrode lead electrode 511 to allow current to flow.

[0060] After the charging process for pre-doping is completed, the pre-doping electrode 513 is no longer needed, so a process of cutting a part of the exterior body to remove it (step S105) is performed. When cutting, a part of the pre-doping lead electrode 518 is also cut. Note that Fig. 5A shows a side view of the exterior body when cutting, and the pre-doping lead electrode 518 is fixed in a position where it faces upward to prevent leakage of the internal electrolyte. The dashed line 521 in Fig. 5A is the cut line, as shown in the figure.

[0061] Then, in an argon gas atmosphere, a process (step S106) is performed to pull out the pre-doping electrode 513 and the second film 517. Fig. 5B shows a side view immediately after the pre-doping electrode 513 is pulled out, illustrating the state in which the pre-doping electrode 513 and the second film 517 are pulled out together with the partially cut pre-doping lead electrode 518. It is important to use insulating tweezers to pull out the pre-doping electrode 513 by utilizing the margin region 517m of the second film 517 so that the positions of the positive electrode and the negative electrode do not shift.

[0062] Then, a third thermocompression bonding is performed under reduced pressure to close the opening, forming a third compression bonding region 509d, and then reduced pressure sealing is performed in step S107.

[0063] Next, after maintaining the ambient temperature at 25° C. for 24 hours, aging treatment (aging 1 and 2) is performed in step S108.

[0064] The first aging treatment was performed under the conditions of 0.01C (1C is 200mA / g) constant current (CC) charging, stopping at 15mAh / g. Note that the value per weight here is the weight of the positive electrode active material. The second aging treatment was performed under the conditions of 0.1C CC charging, stopping at 105mAh / g.

[0065] After the high temperature is maintained, a degassing process (step S109) is performed. The high temperature is maintained at 60° C. for 24 hours. The degassing process is performed to release gas that is generated by charging and discharging.

[0066] A portion of the exterior body (including the temporary pressure-bonded region 509e) is cut to provide an opening, gas is released, and then the opening is resealed (step S110). The side to be cut is the portion that was subjected to the second thermocompression bonding. A fourth thermocompression bonding is performed under reduced pressure, and the opening that was released is closed by the second pressure-bonded region 509c. The reduced pressure is then returned to atmospheric pressure.

[0067] Then, in step S111, aging processes (aging 3 and 4) are performed. The third aging involves an ambient temperature of 25° C., conditions of 0.1 C, constant current / constant voltage (CC / CV) with an upper limit voltage of 4.5 V, cutoff at 0.01 C, followed by discharge at an ambient temperature of 25° C., conditions of 0.2 C, CC, and cutoff at a lower limit voltage of 2.5 V. A rest period may be provided between discharge and the next charge.

[0068] The fourth aging involves cutting off at 0.02C under conditions of 0.2C, CC / CV upper limit voltage of 4.5V at an ambient temperature of 25°C, discharging at 0.2C under CC conditions, and cutting off at a lower limit voltage of 3V.

[0069] Here, the rates of charging and discharging the power storage device will be explained. For example, when a secondary battery with a capacity of X [Ah] is charged at a constant current, a charge rate of 1C is a current value I [A] at which charging is completed in exactly one hour, and a charge rate of 0.2C is a current value I / 5 [A] (i.e., a current value at which charging is completed in exactly five hours). Similarly, a discharge rate of 1C is a current value I [A] at which discharging is completed in exactly one hour, and a discharge rate of 0.2C is a current value I / 5 [A] (i.e., a current value at which discharging is completed in exactly five hours).

[0070] The above steps produce the secondary battery 500. An external view of the produced secondary battery is shown in Fig. 6A, and a cross section taken along the chain line A1-A2 in Fig. 6A is shown in Fig. 6B.

[0071] The secondary battery 500 includes a positive electrode 503 having a positive electrode current collector 501 and a positive electrode active material layer 502, a negative electrode 506 having a negative electrode current collector 504 and a negative electrode active material layer 505, a separator 507, an electrolyte 508, and an exterior body 509. The separator 507 is disposed between the positive electrode 503 and the negative electrode 506 provided within the exterior body 509. The interior of the exterior body 509 is filled with the electrolyte 508.

[0072] The secondary battery 500 has an exterior body 509 sealed with a first pressure-bonding region 509a, a second pressure-bonding region 509c, and a third pressure-bonding region 509d, which surround a sealing region 509b.

[0073] The exterior body 509 is preferably made of a material with low impurity permeability. In particular, it is preferably made of a material with low moisture permeability. For example, it is preferably made of metal. It is preferable to use a film (sometimes called a sheet or foil) as the exterior body.

[0074] In addition, in this embodiment, an example in which the margin region 517m is provided has been shown, but there is no particular limitation as long as the film wrapping the pre-doping electrode is gripped and pulled out, and when the margin region 517m is not provided and a second film 517 of the same size as the positive electrode is used, the second film 517 can be prepared in the same process as the positive electrode, thereby improving productivity. When the margin region 517m is not provided and a second film 517 of the same size as the positive electrode is used, since the sizes are the same, when the positive electrode and the pre-doping electrode are overlapped, there is no portion to grip the second film 517.

[0075] Furthermore, depending on the materials of the second film 517 and the separator 507, impregnating them with an electrolyte may cause surface tension, making it difficult to smoothly remove the pre-doping electrode. When surface tension is present, the metal foil is thin and may tear when the tab is pulled. Furthermore, when tape is used to secure the positive electrode and separator 507 in place, the tape may overlap with the second film 517, hindering smooth removal.

[0076] Therefore, instead of overlapping the positive electrode and pre-doping electrode with the same size perfectly aligned, the positions of the positive electrode and pre-doping electrode are shifted by about 3 mm, so that the second film 517 also protrudes by 3 mm, allowing for smooth removal by grasping that portion. Also, even when fixing the positive electrode and separator 507 with tape to prevent misalignment, the 3 mm shift reduces the overlapping portion between the tape and the second film 517, allowing for smooth removal. When accurately aligning multiple metal foils, it is preferable to use a guide or jig for alignment.

[0077] This embodiment mode can be freely combined with other embodiment modes.

[0078] Embodiment Mode 2 In this embodiment mode, a structure for realizing a secondary battery that can be bent or a bent secondary battery will be described below.

[0079] When a secondary battery is bent, deformation may become large in a localized area of ​​the exterior body. For example, localized deflection may occur in the exterior body. Localized deflection may cause wrinkles. Wrinkles can also be thought of as areas with an extremely small radius of curvature.

[0080] The deflection can be suppressed by processing the film used for the exterior body. For example, the film may be provided with recesses or protrusions. Examples of providing protrusions on the film include embossing the film or forming the film into a bellows shape.

[0081] Metal films are easy to emboss. Furthermore, forming protrusions by embossing increases the surface area of ​​the exterior body exposed to the outside air, for example, the ratio of the surface area to the area seen from the top, resulting in excellent heat dissipation. The protrusions formed on the front (or back) surface of the film by embossing form a closed space with a variable volume, with the film serving as part of the wall of the sealing structure. This closed space can also be said to be formed by the protrusions of the film forming a bellows structure. Furthermore, the method is not limited to embossing, which is a type of press processing, as long as it is a method that can form a relief in part of the film.

[0082] FIG. 7A shows a top view of the region of the film showing convex portions 26 with peaks in a first direction and a striped pattern, where the rectangles indicated by dotted lines 11 become the exterior body. For clarity, FIG. 7A shows the state immediately after the first embossing process. In the second embossing process, convex portions with peaks in a second direction are further arranged alternately so as to intersect with the first direction. Then, FIG. 7B shows the film that becomes the exterior body 23 cut out along dotted lines 11, and the dotted lines in FIG. 7B are the areas to be folded. Note that although an example of two embossing processes is shown here, a film with the pattern shown in FIG. 7B can also be obtained with a single embossing process, depending on the roll used.

[0083] A secondary battery can be fabricated using substantially the same steps as in the first embodiment, except that the film is embossed.

[0084] 8A shows an example of a cross-sectional view of a secondary battery produced according to Embodiment 1. Secondary battery 10 produced using exterior body 23 having an uneven shape can be bent.

[0085] 8A shows the internal structure of secondary battery 10, including a positive electrode 43, a separator 42, a negative electrode 41, a protective material 40, and an electrolyte 45. Note that negative electrode 41 is a laminate of a current collector 54 and a negative electrode active material layer 53.

[0086] As shown in FIG. 8A , the uneven shape of the exterior body 23 can be seen as convex portions 26 and concave portions 27 of the exterior body 23 in a cross-sectional view of the secondary battery 10. The convex portions 26 are convex toward the outside of the exterior body 23, and the concave portions 27 are convex toward the inside of the exterior body 23. The thickness of the exterior body 23 is preferably 80 μm or more and 120 μm or less. The spacing between adjacent convex portions 26 (sometimes referred to as the convex pitch) is preferably 0.5 mm or more and 5 mm or less. The spacing between adjacent concave portions 27 (sometimes referred to as the concave pitch) is preferably 0.5 mm or more and 5 mm or less, and may be equal to or different from the convex pitch described above. The depthwise distance between the vertex (inflection point) of a convex portion 26 and the vertex (inflection point) of an adjacent concave portion 27 is preferably 1 mm or less, more preferably 500 μm or less.

[0087] 8A, an adhesive region 48 may be provided on the outer periphery or edge of the exterior body 23. Pressure may be applied to the exterior body 23 at the adhesive region 48, and depending on the strength of the pressure, the uneven shape may not be visible.

[0088] 8A shows an uneven shape in which the protrusions 26 are continuous with the recesses 27, but the exterior body 23 may also have an uneven shape in which the protrusions 26 and the recesses 27 are spaced apart. The distance between the spaced apart protrusions 26 and the recesses 27 may be constant, or the distance may be shorter at the ends of the exterior body 23 than at the center of the exterior body 23, or may be longer at the ends of the exterior body 23 than at the center of the exterior body 23. An exterior body 23 having such an uneven shape is preferable because it makes the secondary battery 10 easier to bend.

[0089] In addition, in this embodiment, an example is shown in which the protective material 40 is provided between the exterior body 23 and the negative electrode 41. FIG. 8B shows an enlarged view of the exterior body 23, the protective material 40, and the negative electrode 41. The exterior body 23 is a laminate film and has a layered structure. FIG. 8B shows the exterior body 23 having a first member 25a, a second member 25b, and a third member 25c. It is preferable to use an organic material for the first member 25a and the third member 25c, and it is preferable to use a metal material for the second member 25b. It is particularly preferable to use aluminum as the metal material. The layered structure of the exterior body 23 can improve safety while providing flexibility.

[0090] To facilitate bending of the secondary battery 10, it is particularly preferable to use the single-sided coated negative electrode 41 described above. Because the outermost negative electrode 41 is disposed near the exterior body 23, the exterior body 23 is exposed to the potential of the negative electrode 41. Furthermore, because the exterior body 23 also contains the electrolyte 45, the electrolyte 45 may decompose depending on the potential of the negative electrode. Furthermore, bending the secondary battery 10 applies a load to the exterior body 23. This can cause deformation of the exterior body 23, particularly aluminum. In one embodiment of the present invention, the protective material 40 is provided between the exterior body 23 and the negative electrode 41, thereby suppressing deformation of the exterior body 23 due to the above-mentioned factors. To effectively suppress deformation of the exterior body 23, it is preferable that the area of ​​the protective material 40 be the same as or larger than the area of ​​the negative electrode 41.

[0091] It is preferable that the protective material 40 bends together with the secondary battery 10. Specifically, by using a sheet-like material impregnated with the electrolyte solution 45 as the protective material 40, misalignment is more likely to occur at the interface between the protective material 40 and an adjacent material, making the protective material 40 more likely to bend together with the secondary battery 10. In this specification, impregnation includes the electrolyte solution 45 being located in the voids of the protective material 40. The material or structure described above in the description of the separator 42 can be applied to the sheet-like material used for the protective material 40. The protective material 40 can be selected from any of the materials described in the description of the separator 42, and a material different from the separator 42 can also be used.

[0092] FIG. 9A is a perspective view of the secondary battery 10 in a bent state.

[0093] The secondary battery 10 has an exterior body 23, which houses at least a positive electrode and a negative electrode. In this specification and the like, the structure housed in the exterior body 23 may be referred to as an internal structure. Each side of the exterior body 23 is bonded to house the internal structure. The edges may be reinforced with polyimide film tape or the like to strengthen the bond between the edges. In FIG. 9A , the exterior body 23 is illustrated as a polygon having two long sides and two short sides, i.e., a rectangle, with arrows 24 pointing in the direction of the short sides. Each corner of the exterior body 23 (four corners in FIG. 9A ) may be a right angle, a notched shape, or a rounded shape. The corners of the exterior body 23 may all have the same shape, or may have different shapes selected from a right angle, a notched shape, and a rounded shape.

[0094] The secondary battery 10 shown in Fig. 9A has a first lead electrode 21 and a second lead electrode 22. The secondary battery 10 shown in Fig. 9A is an example in which the first lead electrode 21 and the second lead electrode 22 are located on the short sides of the exterior body 23. The secondary battery shown in the first embodiment is also of a similar type, but is not particularly limited thereto, and the secondary battery shown in Fig. 9B can also be fabricated.

[0095] The secondary battery 10 shown in Fig. 9B is an example in which the first lead electrode 21 and the second lead electrode 22 are located on the long sides of the exterior body 23. When producing such a secondary battery, as shown in Fig. 10, the negative electrode lead electrode 511 is ultrasonically bonded to the negative electrode, the positive electrode lead electrode 510 is ultrasonically bonded to the positive electrode, and the pre-doping lead electrode 518 is ultrasonically bonded to the pre-doping electrode. Then, according to embodiment 1, a portion is cut to remove the pre-doping electrode, and the battery is resealed, thereby producing the secondary battery 10 shown in Fig. 9B.

[0096] As shown in this embodiment, a secondary battery can be manufactured without being limited by the shape or size of the exterior body, and for example, the long side of the exterior body 23 can be 5 cm or more, preferably 10 cm or more, and more preferably 12 cm or more. Specifically, a secondary battery of B7 size (91 mm x 128 mm) can be manufactured.

[0097] This embodiment mode can be freely combined with other embodiment modes.

[0098] Embodiment 3 An example in which a secondary battery according to one embodiment of the present invention is mounted on a vehicle, typically a transportation vehicle, will be described.

[0099] Furthermore, by installing lithium-ion secondary batteries in vehicles, next-generation clean energy automobiles such as hybrid vehicles (HVs), electric vehicles (EVs), plug-in hybrid vehicles (PHVs), etc. Secondary batteries can also be installed in transportation vehicles such as agricultural machinery, mopeds including electrically assisted bicycles, motorcycles, electric wheelchairs, electric carts, small or large ships, submarines, aircraft such as fixed-wing aircraft and rotary-wing aircraft, rockets, artificial satellites, space probes, planetary probes, and spacecraft.

[0100] 11A to 11D illustrate examples of transportation vehicles using one embodiment of the present invention. The automobile 2001 shown in FIG. 11A is an electric automobile that uses an electric motor as a power source for traveling. Alternatively, it is a hybrid automobile that can appropriately select and use an electric motor and an engine as a power source for traveling. An example of the secondary battery described in the above embodiment is installed in one or more locations. When the secondary battery of the present invention is used as a secondary battery mounted on a vehicle, a small initial irreversible capacity, an increased initial capacity, and excellent cycle characteristics are expected.

[0101] 11A includes a battery pack 2200, which includes a battery module to which a plurality of secondary batteries are connected. The battery pack 2200 preferably further includes a charge control device electrically connected to the battery module.

[0102] Furthermore, the automobile 2001 can charge its secondary battery by receiving power supply from an external charging facility using a plug-in system, a contactless power supply system, or the like. When charging, the charging method and connector standards may be appropriately determined using a predetermined system such as CHAdeMO (registered trademark) or Combo. The secondary battery can be supplied from a charging station installed in a commercial facility or a home power source. For example, plug-in technology can be used to charge the power storage device installed in the automobile 2001 using external power supply. Charging can be performed by converting AC power to DC power via a conversion device such as an AC-DC converter.

[0103] Although not shown, a power receiving device can be mounted on a vehicle and can be charged by receiving power contactlessly from a ground-based power transmitting device. In the case of this contactless power supply method, by incorporating a power transmitting device into a road or an exterior wall, charging can be performed not only while the vehicle is stopped but also while the vehicle is moving. This contactless power supply method can also be used to transmit and receive power between two vehicles. Furthermore, solar cells can be installed on the exterior of the vehicle, and the secondary battery can be charged while the vehicle is stopped and moving. For such contactless power supply, an electromagnetic induction method or a magnetic field resonance method can be used.

[0104] 11B shows a large transport vehicle 2002 having an electrically controlled motor as an example of a transport vehicle. The battery module of the transport vehicle 2002 is, for example, a four-cell unit of secondary batteries with a nominal voltage of 3.0 V to 5.0 V, with 48 cells connected in series to achieve a maximum voltage of 170 V. Other than the number of secondary batteries in the battery pack 2201, the battery pack 2201 has the same functions as those shown in FIG. 11B , and therefore a description thereof will be omitted. If the secondary battery of the present invention is used as the secondary battery of the battery pack 2201, a small initial irreversible capacity, an increased initial capacity, and excellent cycle characteristics can be expected.

[0105] 11C shows, as an example, a large transport vehicle 2003 having an electrically controlled motor. The battery module of the transport vehicle 2003 has, for example, 100 or more secondary batteries with a nominal voltage of 3.0 V to 5.0 V connected in series to produce a maximum voltage of 600 V. Furthermore, except for the number of secondary batteries constituting the battery module of the battery pack 2202, the battery module has the same functions as that shown in FIG. 11B, and therefore a description thereof will be omitted. When the secondary battery of the present invention is used as the secondary battery in the module, a small initial irreversible capacity, an increased initial capacity, and excellent cycle characteristics can be expected.

[0106] Fig. 11D shows, as an example, an aircraft 2004 having an engine that burns fuel. The aircraft 2004 shown in Fig. 11D has wheels for takeoff and landing, and can therefore be considered part of a transportation vehicle, and has a battery pack 2203 that includes a battery module formed by connecting multiple secondary batteries and includes the battery module and a charge control device.

[0107] The battery module of the aircraft 2004 is, for example, eight 4 V secondary batteries connected in series, with a maximum voltage of 32 V. Other than the number of secondary batteries constituting the battery module of the battery pack 2203, the battery module has the same functions as those shown in FIG. 11B, and therefore a description thereof will be omitted.

[0108] The content of this embodiment mode can be combined with the content of other embodiment modes as appropriate.

[0109] Embodiment 4 In this embodiment, an example in which a secondary battery according to one embodiment of the present invention is mounted on a vehicle such as a motorcycle or a bicycle will be described.

[0110] 12A illustrates an example of an electric bicycle using the secondary battery of one embodiment of the present invention. The secondary battery of one embodiment of the present invention can be applied to an electric bicycle 8700 illustrated in FIG. 12A. The secondary battery of one embodiment of the present invention may include a protection circuit.

[0111] The electric bicycle 8700 includes a power storage device 8702. The power storage device 8702 can supply electricity to a motor that assists a rider. The power storage device 8702 is portable and is shown in a state removed from the bicycle in FIG. 12B . The power storage device 8702 includes a plurality of secondary batteries 8701 of one embodiment of the present invention, and the remaining battery charge and the like can be displayed on a display unit 8703. When the secondary battery of the present invention is used as the secondary battery 8701, the initial irreversible capacity is small, and an increase in initial capacity and excellent cycle characteristics are expected.

[0112] The power storage device 8702 also includes a control circuit 8704 capable of controlling charging or detecting an abnormality of the secondary battery. The control circuit 8704 is electrically connected to the positive and negative electrodes of the secondary battery 8701. This can greatly contribute to preventing accidents such as fires caused by secondary batteries.

[0113] 12C illustrates an example of a motorcycle using a secondary battery of one embodiment of the present invention. A scooter 8600 shown in FIG. 12C includes a power storage device 8602, a side mirror 8601, and a turn signal light 8603. The power storage device 8602 can supply electricity to the turn signal light 8603. The use of the secondary battery of the present invention is expected to result in a small initial irreversible capacity, an increased initial capacity, and excellent cycle characteristics.

[0114] 12C can store a power storage device 8602 in an under-seat storage space 8604. The power storage device 8602 can be stored in the under-seat storage space 8604 even if the under-seat storage space 8604 is small.

[0115] The content of this embodiment mode can be combined with the content of other embodiment modes as appropriate.

[0116] Embodiment 5 In this embodiment, an example of mounting a secondary battery according to one embodiment of the present invention in an electronic device will be described. Examples of electronic devices mounting a secondary battery include television sets (also referred to as televisions or television receivers), computer monitors, digital cameras, digital video cameras, digital photo frames, mobile phones (also referred to as mobile phones or mobile phone devices), portable game consoles, personal digital assistants, sound players, and large game consoles such as pachinko machines. Examples of personal digital assistants include notebook personal computers, tablet devices, e-book readers, and mobile phones.

[0117] 13A shows an example of a mobile phone. Mobile phone 2100 includes a display unit 2102 built into housing 2101, as well as operation buttons 2103, an external connection port 2104, a speaker 2105, a microphone 2106, and the like. Mobile phone 2100 also includes a lithium-ion battery 2107. Use of the secondary battery of the present invention is expected to result in a small initial irreversible capacity, an increased initial capacity, and excellent cycle characteristics.

[0118] The mobile phone 2100 can execute various applications such as mobile phone calls, e-mail, document browsing and creation, music playback, internet communication, and computer games.

[0119] The operation button 2103 can be provided with various functions such as time setting, power on / off operation, wireless communication on / off operation, silent mode activation / deactivation, power saving mode activation / deactivation, etc. For example, the functions of the operation button 2103 can be freely set by an operating system incorporated in the mobile phone 2100.

[0120] The mobile phone 2100 is also capable of performing standardized short-range wireless communication, and can also make hands-free calls by communicating with a wirelessly enabled headset, for example.

[0121] The mobile phone 2100 also includes an external connection port 2104, which allows direct data exchange with other information terminals via a connector. Charging can also be performed via the external connection port 2104. Note that charging may be performed by wireless power supply without using the external connection port 2104.

[0122] The mobile phone 2100 preferably has a sensor, such as a fingerprint sensor, a pulse sensor, a body temperature sensor, a touch sensor, a pressure sensor, an acceleration sensor, or the like.

[0123] FIG. 13B shows an unmanned aerial vehicle 2300 having multiple rotors 2302. The unmanned aerial vehicle 2300 is sometimes called a drone. The unmanned aerial vehicle 2300 includes a lithium-ion battery 2301 according to one embodiment of the present invention, a camera 2303, and an antenna (not shown). The unmanned aerial vehicle 2300 can be remotely controlled via the antenna. Use of the secondary battery of the present invention is expected to result in a small initial irreversible capacity, an increased initial capacity, and excellent cycle characteristics.

[0124] Fig. 13C shows an example of a robot. The robot 6400 shown in Fig. 13C includes a secondary battery 6409, an illuminance sensor 6401, a microphone 6402, an upper camera 6403, a speaker 6404, a display unit 6405, a lower camera 6406, an obstacle sensor 6407, a movement mechanism 6408, a transmitting / receiving device, a computing device, etc.

[0125] The microphone 6402 has a function of detecting the user's speaking voice, environmental sounds, etc. The speaker 6404 has a function of emitting sound. The robot 6400 can communicate with the user using the microphone 6402 and the speaker 6404.

[0126] The display unit 6405 has a function of displaying various information. The robot 6400 can display information desired by the user on the display unit 6405. The display unit 6405 may be equipped with a touch panel. The display unit 6405 may also be a detachable information terminal, which can be installed in a fixed position on the robot 6400 to enable charging and data transfer.

[0127] The upper camera 6403 and the lower camera 6406 have the function of capturing images of the surroundings of the robot 6400. In addition, the obstacle sensor 6407 can detect the presence or absence of obstacles in the direction of travel when the robot 6400 moves forward using the movement mechanism 6408. The robot 6400 can recognize the surrounding environment and move safely using the upper camera 6403, the lower camera 6406, and the obstacle sensor 6407.

[0128] The robot 6400 includes a secondary battery 6409 according to one embodiment of the present invention and a semiconductor device or an electronic component in its internal region. The use of the secondary battery of the present invention is expected to result in a small initial irreversible capacity, an increased initial capacity, and excellent cycle characteristics.

[0129] 13D shows an example of a cleaning robot. The cleaning robot 6300 includes a display unit 6302 arranged on the top surface of a housing 6301, a plurality of cameras 6303 arranged on the side surfaces, a brush 6304, operation buttons 6305, a secondary battery 6306, various sensors, and the like. Although not shown, the cleaning robot 6300 is provided with tires, a suction port, and the like. The cleaning robot 6300 can move by itself, detect dust 6310, and suck up the dust from a suction port arranged on the bottom surface.

[0130] For example, the cleaning robot 6300 can analyze an image captured by the camera 6303 to determine whether or not there is an obstacle such as a wall, furniture, or a step. Furthermore, if an object that may become entangled in the brush 6304, such as a wire, is detected through image analysis, the cleaning robot 6300 can stop the rotation of the brush 6304. The cleaning robot 6300 includes a secondary battery 6306 according to one embodiment of the present invention and a semiconductor device or electronic component in its internal area. Use of the secondary battery of the present invention is expected to result in a small initial irreversible capacity, an increased initial capacity, and excellent cycle characteristics.

[0131] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0132] Embodiment 6 In this embodiment, an example in which a secondary battery which is one embodiment of the present invention is mounted on space equipment will be described.

[0133] 14A shows an artificial satellite 6800 as an example of space equipment. The artificial satellite 6800 has a body 6801, a solar panel 6802, an antenna 6803, and a secondary battery 6805. The solar panel may be called a solar cell module.

[0134] When sunlight is irradiated onto the solar panel 6802, the power required for the operation of the satellite 6800 is generated. However, for example, in a situation where sunlight is not irradiated onto the solar panel or where the amount of sunlight irradiating the solar panel is low, the generated power is reduced. Therefore, there is a possibility that the power required for the operation of the satellite 6800 will not be generated. In order to operate the satellite 6800 even in a situation where the generated power is low, it is preferable to provide the satellite 6800 with a secondary battery 6805. When the secondary battery of the present invention is used, a small initial irreversible capacity, an increased initial capacity, and excellent cycle characteristics are expected.

[0135] The satellite 6800 can generate a signal. The signal is transmitted via the antenna 6803, and can be received by, for example, a receiver installed on the ground or another satellite. By receiving the signal transmitted by the satellite 6800, the position of the receiver that received the signal can be measured, for example. As described above, the satellite 6800 can constitute, for example, a satellite positioning system.

[0136] Alternatively, the artificial satellite 6800 may be configured to include a sensor. For example, by including a visible light sensor, the artificial satellite 6800 may have the function of detecting sunlight reflected from an object on the ground. Alternatively, by including a thermal infrared sensor, the artificial satellite 6800 may have the function of detecting thermal infrared rays emitted from the earth's surface. As described above, the artificial satellite 6800 may function as, for example, an earth observation satellite.

[0137] FIG. 14B shows a probe 6900 equipped with a solar sail (also called a solar sail) as an example of space equipment. The probe 6900 includes a body 6901, a solar sail 6902, and a secondary battery 6905. Use of the secondary battery of the present invention is expected to result in a low initial irreversible capacity, an increased initial capacity, and excellent cycle characteristics. When photons emitted from the sun strike the surface of the solar sail 6902, momentum is transferred to the solar sail 6902. Therefore, it is preferable that the surface of the solar sail 6902 has a highly reflective thin film and faces the sun.

[0138] The solar sail 6902 may also be designed to be folded up small until it leaves the atmosphere, and then deployed into a large sheet shape outside the Earth's atmosphere (outer space) as shown in Figure 14B.

[0139] FIG. 14C shows a spacecraft 6910 as an example of space equipment. The spacecraft 6910 has a body 6911, a solar panel 6912, and a secondary battery 6913. Use of the secondary battery of the present invention is expected to result in a small initial irreversible capacity, an increased initial capacity, and excellent cycle characteristics. The body 6911 can have, for example, a pressurized compartment and a non-pressurized compartment. The pressurized compartment may be designed to accommodate a crew member. Electricity generated by sunlight irradiating the solar panel 6912 can be charged into the secondary battery 6913.

[0140] 14D shows a rover 6920 as an example of space equipment. The rover 6920 includes a body 6921 and a secondary battery 6923. Use of the secondary battery of the present invention is expected to result in a small initial irreversible capacity, an increased initial capacity, and excellent cycle characteristics. The rover 6920 may also include a solar panel 6922.

[0141] The rover 6920 may be designed to allow a crew member to ride in. The secondary battery 6923 may be charged with electricity generated by sunlight irradiating the solar panel 6912, or the secondary battery 6923 may be charged with electricity generated by other power sources, such as a fuel cell, a radioisotope thermoelectric converter, or the like.

[0142] The content of this embodiment mode can be combined with the content of other embodiment modes as appropriate.

[0143] 10: secondary battery, 11: dotted line, 21: first lead electrode, 22: second lead electrode, 23: exterior body, 24: arrow, 25a: first member, 25b: second member, 25c: third member, 26: convex portion, 27: concave portion, 40: protective material, 41: negative electrode, 42: separator, 43: positive electrode, 45: electrolyte, 48: adhesive region, 500: secondary battery, 501: positive electrode current collector, 502: positive electrode active material layer, 503: positive electrode, 504: negative electrode current collector, 505: negative electrode active material layer, 506: negative electrode, 507: separator, 508: electrolyte, 509: exterior body, 509a: first pressure-bonding region, 509b: sealing region , 509c: second pressure-bonding region, 509d: third pressure-bonding region, 509e: temporary pressure-bonding region, 510: positive electrode lead electrode, 511: negative electrode lead electrode, 512: pre-doping active material layer, 513: pre-doping electrode, 514a: adhesive region, 514b: adhesive region, 517: second film, 517m: margin region, 518: pre-doping lead electrode, 2001: automobile, 2002: transport vehicle, 2003: transport vehicle, 2004: aircraft, 2100: mobile phone, 2101: housing, 2102: display unit, 2103: operation button, 2104: external connection port, 2105: speaker, 21 06: microphone, 2107: lithium ion battery, 2200: battery pack, 2201: battery pack, 2202: battery pack, 2203: battery pack, 2300: unmanned aerial vehicle, 2301: lithium ion battery, 2302: rotor, 2303: camera, 6300: cleaning robot, 6301: housing, 6302: display unit, 6303: camera, 6304: brush, 6305: operation button, 6306: secondary battery, 6310: dust, 6400: robot, 6401: illuminance sensor, 6402: microphone, 6403: upper camera, 6404: speaker, 6405: surface display unit, 6406: lower camera, 6407: obstacle sensor, 6408: moving mechanism, 6409: secondary battery, 6800: artificial satellite, 6801: airframe, 6802: solar panel, 6803: antenna, 6805: secondary battery, 6900: probe, 6901: airframe, 6902: solar sail, 6905: secondary battery, 6910: spacecraft, 6911: airframe, 6912: solar panel, 6913: secondary battery, 6920: rover, 6921: airframe, 6922: solar panel, 6923: secondary battery, 8600: scooter, 8601: side mirror, 8602: power storage device,8603: Turn signal light, 8604: Under-seat storage, 8700: Electric bicycle, 8701: Secondary battery, 8702: Power storage device, 8703: Display unit, 8704: Control circuit,

Claims

Inside a bag-shaped exterior body, a positive electrode wrapped with a first film, an electrode wrapped with a second film, a negative electrode having a negative electrode active material, are housed, an electrolytic solution is put into the bag-shaped exterior body, the bag-shaped exterior body is sealed, the electrode has a first lead, and a first terminal is connected to the first lead, the negative electrode has a second lead, and a second terminal is connected to the second lead, a charging process of flowing a current through the first terminal and the second terminal is performed to perform a pre-doping process, after cutting a part of the bag-shaped exterior body, the end of the second film is pulled to extract the electrode, A method for manufacturing a secondary battery in which the bag-shaped exterior body is sealed again. 　 In claim 1, the positive electrode is a positive electrode current collector on which a first positive electrode active material layer is formed, and before sealing the bag-shaped exterior body, a third lead is connected to a tab portion of the positive electrode current collector, the electrode is a current collector on which a second positive electrode active material layer is formed, and before sealing the bag-shaped exterior body, the first lead is connected to a tab portion of the current collector, A method for manufacturing a secondary battery in which the negative electrode is a negative electrode current collector on which a negative electrode active material layer is formed, and before sealing the bag-shaped exterior body, the second lead is connected to a tab portion of the negative electrode current collector. 　 In claim 1, before sealing the bag-shaped exterior body, the first film and the second film are in contact with each other and overlapped inside the bag-shaped exterior body, the area of the first film is larger than that of the second film, A method for manufacturing a secondary battery in which, when extracting the electrode, an end portion of the first film that does not overlap the second film is pulled. 　 In claim 1, a method for manufacturing a secondary battery in which the positive electrode and the negative electrode are taken as a set, and a plurality of sets are housed in the bag-shaped exterior body. 　 In claim 1, a method for manufacturing a secondary battery in which, when sealing the bag-shaped exterior body, the leads of the positive electrode, the leads of the negative electrode, and the leads of the electrode do not overlap. 　 In claim 1, a method for manufacturing a secondary battery in which the positive electrode and the electrode are formed of the same material and in the same process. 　 In claim 1, a method for manufacturing a secondary battery in which the negative electrode active material contains silicon.

Images