Secondary battery manufacturing method

Abstract

To suppress the deterioration of the performance of a secondary battery caused by the presence of gas inside an electrode body.SOLUTION: A secondary battery manufacturing method includes a step S2 of housing an electrode assembly, in which a positive electrode plate, a separator, and a negative electrode plate are wound around a winding axis, and an electrolyte in a case and sealing the case, and a step of removing gas from inside the electrode assembly after housing the electrode assembly and the electrolyte in the case and sealing the case. The step of removing gas from inside the electrode assembly includes a step S4 of pressing the electrode assembly through the case from outside the case, and a step S5 of pressing the electrode assembly through the case and then charging and discharging the secondary battery with the winding axis tilted from the horizontal direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present technology relates to a method for manufacturing a secondary battery. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2012-69404 (Patent Document 1) is a prior art document that discloses the configuration of an electric device. The electric device described in Patent Document 1 includes a power generation element, an exterior material, a pipe, and a balloon. The exterior material houses the power generation element. One end of the pipe opens inside the exterior material. The balloon stores an electrolyte where the other end of the pipe opens, and is housed in a sealed case, so that it expands when the internal air pressure of the sealed case drops. If gas is generated inside the exterior material, the gas is sucked out by the balloon through the pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-69404 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, gas generated on the outside of the electrode body inside the secondary battery can be removed, but gas present inside the electrode body cannot be removed. Therefore, the presence of gas inside the electrode body can have adverse effects such as a decrease in battery capacity, an increase in electrical resistance, or the occurrence of Li deposition, which can reduce the performance of the secondary battery.

[0005] The present technology has been made to solve the above-mentioned problems, and aims to provide a method for manufacturing a secondary battery that can suppress the deterioration of performance of the secondary battery due to the presence of gas inside the electrode body. [Means for solving the problem]

[0006] The present technology provides the following method for manufacturing a secondary battery. [1] a step of accommodating an electrode assembly in which a positive electrode plate, a separator, and a negative electrode plate are wound around a winding axis, together with an electrolyte, in a case and sealing the case; a step of housing the electrode assembly and the electrolyte solution in the case and sealing the case, and then removing gas from inside the electrode assembly, The step of removing the gas from inside the electrode body includes: pressing the electrode body from outside the case through the case; and then charging and discharging the secondary battery in a state in which the winding axis is tilted from the horizontal direction. [2] The method for manufacturing a secondary battery according to [1], wherein the step of charging and discharging the secondary battery includes repeatedly charging and discharging the secondary battery up to a predetermined charge rate. [3] The method for producing a secondary battery according to [1] or [2], wherein the step of charging and discharging the secondary battery includes charging the secondary battery to a charge rate of 50% or less and then discharging the secondary battery. [4] further comprising a step of inspecting a charge / discharge state of the secondary battery; The method for manufacturing a secondary battery according to any one of [1] to [3], wherein the step of removing the gas from inside the electrode body is carried out before the step of inspecting the charge / discharge state of the secondary battery. [5] further comprising a step of inspecting a charge / discharge state of the secondary battery; The method for manufacturing a secondary battery according to any one of [1] to [3], wherein the step of removing the gas from inside the electrode body is carried out after the step of inspecting the charge / discharge state of the secondary battery. [Effects of the Invention]

[0007] According to the present technology, it is possible to suppress a decrease in performance of a secondary battery due to the presence of gas inside an electrode assembly. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a configuration of a secondary battery according to a first embodiment of the present technology. [Figure 2] 1 is a schematic diagram illustrating an internal configuration of a secondary battery according to a first embodiment of the present technology. [Figure 3] 1 is a perspective view showing a configuration of an electrode body according to a first embodiment of the present technology. [Figure 4] 3 is a flowchart showing a method for manufacturing a secondary battery according to the first embodiment of the present technology. [Figure 5] 3A to 3C are schematic diagrams illustrating a process of accommodating and sealing an electrode assembly and an electrolyte solution in a case included in the secondary battery according to the first embodiment of the present technology. [Figure 6] 5A and 5B are schematic diagrams illustrating a process of pressing an electrode assembly through a case included in the secondary battery according to the first embodiment of the present technology. [Figure 7] 4 is a schematic diagram showing a state in which gas inside the electrode body moves when the electrode body included in the secondary battery according to the first embodiment of the present technology is pressed. FIG. [Figure 8] 1 is a schematic diagram showing a state in which a secondary battery according to a first embodiment of the present technology is tilted from the horizontal direction and charged and discharged. [Figure 9] 1 is a schematic diagram showing a state in which gas present in a curved portion of an electrode body is removed to the outside of the electrode body by charging and discharging the secondary battery according to embodiment 1 of the present technology while tilted from the horizontal direction. FIG. [Figure 10] 10 is a flowchart showing a method for manufacturing a secondary battery according to a second embodiment of the present technology. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present technology will be described. Note that the same or corresponding parts are denoted by the same reference characters, and description thereof may not be repeated.

[0010] In the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects and advantages mentioned in the present embodiments.

[0011] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain feature is included, other features may or may not be included.

[0012] Furthermore, when geometric terms and terms expressing positional and directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0013] In this specification, the term "battery" is not limited to lithium-ion batteries, but may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, the term "electrode" may collectively refer to a positive electrode and a negative electrode.

[0014] Furthermore, the "battery module" including the secondary battery in this specification can be mounted in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), etc. However, the use of the "battery module" including the secondary battery in this specification is not limited to vehicle use.

[0015] In the drawings, the direction in which the positive and negative terminals of the secondary battery are aligned is the X direction, the direction in which the pair of long side walls of the case are aligned is the Y direction, and the direction in which the sealing plate and bottom surface of the case are aligned is the Z direction. In addition, to make the invention easier to understand, the dimensions of each component in the drawings may be shown differently from the actual dimensions.

[0016] (Embodiment 1) Fig. 1 is a perspective view showing a configuration of a secondary battery according to embodiment 1 of the present technology. Fig. 2 is a schematic view showing an internal configuration of a secondary battery according to embodiment 1 of the present technology. Fig. 3 is a perspective view showing a configuration of an electrode body according to embodiment 1 of the present technology.

[0017] The secondary battery according to this embodiment is, for example, a nonaqueous lithium ion battery. The capacity of the secondary battery is, for example, 4 Ah. As shown in FIGS. 1 to 3, the secondary battery 100 includes an electrode terminal 110, a case 120, a gas release valve 130, and an electrode assembly 140.

[0018] The electrode terminal 110 has a positive electrode terminal 111 and a negative electrode terminal 112. The electrode terminal 110 is formed on a case 120.

[0019] The case 120 is a container that houses the electrode assembly 140 and the electrolyte. The case 120 has a substantially rectangular parallelepiped shape. The case 120 is made of aluminum, an aluminum alloy, iron, or an iron alloy such as stainless steel.

[0020] As shown in FIG. 1, the case 120 has a sealing plate 121, a bottom surface 122, a pair of long side walls 123, and a pair of short side walls .

[0021] The sealing plate 121 forms the upper surface of the case 120. The electrode terminals 110 are disposed on the sealing plate 121. The bottom surface 122 faces the sealing plate 121 in the Z direction.

[0022] The pair of long side walls 123 and the pair of short side walls 124 constitute the side surfaces of the case 120. The pair of long side walls 123 and the pair of short side walls 124 intersect with the sealing plate 121 and the bottom surface 122, respectively. The pair of long side walls 123 face each other in the Y direction, with the electrode body 140 sandwiched between them. The pair of short side walls 124 face each other in the X direction, with the electrode body 140 sandwiched between them. Each of the pair of long side walls 123 has a larger area than each of the pair of short side walls 124.

[0023] The gas exhaust valve 130 breaks when the pressure inside the case 120 reaches or exceeds a predetermined value, thereby allowing the gas inside the case 120 to be exhausted to the outside of the case 120.

[0024] 1 and 2, the positive electrode terminal 111 and the negative electrode terminal 112 are arranged on the same surface (on the sealing plate 121), but this configuration is not limiting. The positive electrode terminal 111 and the negative electrode terminal 112 may be located on different surfaces, or may be located so as to face each of the pair of short side walls 124.

[0025] The electrode assembly 140 functions as a power generating element. As shown in FIG.

[0026] The electrode body 140 in this embodiment is a wound electrode body in which a positive electrode plate 150, a negative electrode plate 160, and a separator 170 are wound around a winding axis A. After the positive electrode plate 150, the negative electrode plate 160, and the separator 170 are wound, the electrode body 140 is pressed in a direction perpendicular to the winding axis A (the Y direction in FIG. 3 ). As a result, the electrode body 140 is formed into a flat shape including a flat portion 141 and a curved portion 142.

[0027] The electrode assembly 140 may be a laminated electrode assembly in which positive electrode plates 150, separators 170, and negative electrode plates 160 are alternately laminated. When the electrode assembly is a laminated electrode assembly, the electrode assembly may be laminated by folding long positive electrode plates, separators, and negative electrode plates in a zigzag pattern.

[0028] The positive electrode plate 150 has a positive electrode core 151 and a positive electrode active material layer 152. The positive electrode core 151 is a conductive sheet. The positive electrode core 151 is, for example, an aluminum alloy foil. The positive electrode active material layer 152 is disposed on the surface of the positive electrode core 151.

[0029] The positive electrode active material may be a lithium transition metal composite oxide, etc. In this embodiment, the lithium transition metal composite oxide is, for example, lithium nickel cobalt manganese oxide.

[0030] The negative electrode plate 160 has a negative electrode core 161 and a negative electrode active material layer 162. The negative electrode core 161 is a conductive sheet. The negative electrode core 161 is, for example, a copper alloy foil. The negative electrode active material layer 162 is disposed on the surface of the negative electrode core 161.

[0031] Examples of the negative electrode active material include carbon materials such as artificial graphite, natural graphite, amorphous coated graphite, and amorphous carbon, non-carbon materials such as SiO, and mixtures of carbon materials and non-carbon materials.

[0032] The separator 170 is provided to insulate the positive electrode plate 150 from the negative electrode plate 160. The separator 170 has a structure including only a porous sheet as a substrate, or including a substrate and a heat-resistant layer.

[0033] The substrate has ion permeability and insulating properties, and examples thereof include a microporous thin film, a woven fabric, or a nonwoven fabric. Suitable materials for the substrate include olefin resins such as polyethylene (PE) and polypropylene (PP), or cellulose. The substrate may be made of, for example, a PE layer alone, or a laminate in which a PE layer is sandwiched between two PP layers.

[0034] The electrode assembly 140 described above is housed in the case 120 and then impregnated with an electrolytic solution. The electrolytic solution is made of a non-aqueous electrolyte. The non-aqueous electrolyte includes a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent. The non-aqueous electrolyte is not limited to a liquid electrolyte (nonaqueous electrolytic solution), but may also be a solid electrolyte using a gel polymer or the like. The non-aqueous solvent may be, for example, an ester, an ether, a nitrile such as acetonitrile, an amide such as dimethylformamide, or a mixed solvent of two or more of these.

[0035] The number of electrode bodies 140 housed in one secondary battery 100 may be one or more. When there are multiple electrode bodies, it is desirable that the multiple electrode bodies are arranged side by side in the direction in which the pair of long side walls 123 are arranged (Y direction).

[0036] Hereinafter, a method for manufacturing the secondary battery 100 according to this embodiment will be described. Fig. 4 is a flowchart showing a method for manufacturing the secondary battery according to the first embodiment of the present technology.

[0037] First, as shown in Fig. 4, an electrode assembly 140 is prepared (step S1). The electrode assembly 140 in this embodiment is a wound electrode assembly in which the above-mentioned positive electrode plate 150, separator 170, and negative electrode plate 160 are wound around a winding axis.

[0038] FIG. 5 is a schematic diagram showing a process of accommodating and sealing an electrode assembly and an electrolyte solution in a case included in the secondary battery according to the first embodiment of the present technology.

[0039] Next, as shown in FIGS. 4 and 5, the electrode assembly 140 and the electrolyte 10 are housed in the case 120 and sealed (step S2). The electrolyte 10 is poured into the case 120 through a filling hole (not shown). The filling hole is sealed with a sealing member (not shown). This seals the case 120. For example, a blind rivet or other metal member can be used as the sealing member.

[0040] The electrode assembly 140 is a wound electrode assembly, and is impregnated with the electrolyte 10 from both ends in the direction of the winding axis A. For this reason, the electrode assembly 140 needs to be in a state in which the direction of the winding axis A is aligned horizontally. In Figure 5, the X direction is the horizontal direction, and the winding axis A of the electrode assembly 140 is aligned with the X direction.

[0041] 4, gas is generated from the electrode body 140 (step S3). Specifically, the secondary battery 100 is charged or subjected to heat treatment (high-temperature aging) to generate gas inside the electrode body 140 by decomposing the electrolyte solution 10 impregnated inside the electrode body 140.

[0042] Next, electrode body 140 and electrolyte solution 10 are housed in case 120 and sealed, and after generating gas in electrode body 140, the gas is removed from inside electrode body 140. The step of removing gas from inside electrode body 140 includes the steps of pressing electrode body 140 through case 120 from the outside of case 120, and, after pressing electrode body 140 through case 120, charging and discharging secondary battery 100 with winding axis A tilted from the horizontal direction.

[0043] Fig. 6 is a schematic diagram showing a process of pressing an electrode body through a case included in the secondary battery according to embodiment 1 of the present technology. Fig. 7 is a schematic diagram showing a state in which gas inside the electrode body moves as a result of the electrode body being pressed.

[0044] As shown in FIGS. 4, 6, and 7, in the step of removing gas from inside the electrode body 140, first, the electrode body 140 is pressed from outside the case 120 via the case 120 (step S4). The electrode body 140 is pressed by a pressing jig 2 via the case 120. The pressing jig 2 presses the area of ​​the pair of long side walls 123 of the case 120 where the electrode body 140 is located. The flat surface portion 141 of the electrode body 140 is mainly pressed.

[0045] The electrode assembly 140 is sized according to the dimensions of the case 120, which are calculated by design or experimentation so that the positive electrode plate 150, the negative electrode plate 160, and the separator 170 are in close contact with each other. The close contact between the positive electrode plate 150, the negative electrode plate 160, and the separator 170 means that they are in contact with each other to the extent that a decrease in battery capacity, an increase in electrical resistance, or Li deposition does not occur.

[0046] In this embodiment, a load is applied to the electrode assembly 140 until it reaches a dimension equivalent to the total thickness of the positive electrode plate 150, the negative electrode plate 160, and the separator 170. The pressing force F of the pressing jig 2 is, for example, a maximum of 1000 kgf. Note that the pressing force F may be a load that does not qualitatively clog the separator 170. Furthermore, the electrode assembly 140 may be subjected to constant pressure restraint using a load calculated by design or experimentation so that the positive electrode plate 150, the negative electrode plate 160, and the separator 170 come into close contact with each other.

[0047] When the electrode body 140 is pressed, the gas 20 generated inside the electrode body 140 moves. Specifically, since the flat portion 141 of the electrode body 140 is mainly pressed, when the electrode body 140 is pressed, the gas 20 generated inside the electrode body 140 moves and is removed to the outside of the electrode body 140 from both ends of the electrode body 140 in the direction of the winding axis A. In FIG. 7, the gas 20 is removed in the direction DR1. Furthermore, the gas 20 generated inside the electrode body 140 moves to the curved portion 142 of the electrode body 140. In FIG. 7, the gas 20 moves in the direction DR2.

[0048] In this embodiment, one secondary battery 100 is pressed by the pressing jig 2, but the present invention is not limited to this configuration, and a plurality of secondary batteries may be simultaneously pressed by the pressing jig 2. Furthermore, pressing of the secondary battery 100 may be performed from the step of generating gas in the electrode body 140 (for example, when charging the secondary battery).

[0049] Fig. 8 is a schematic diagram showing a state in which the secondary battery according to the first embodiment of the present technology is tilted from the horizontal direction and charged / discharged. Fig. 9 is a schematic diagram showing a state in which the secondary battery according to the first embodiment of the present technology is tilted from the horizontal direction and charged / discharged, thereby removing gas present in the curved portion of the electrode body to the outside of the electrode body.

[0050] 4, 8, and 9, after electrode body 140 is pressed through case 120, secondary battery 100 is charged and discharged with winding axis A tilted from the horizontal direction (step S5). In the present embodiment, electrode body 140 is tilted through case 120, for example, by rotating case 120 while it is pressed by pressing jig 2.

[0051] When the secondary battery 100 is charged and discharged, the electrode body 140 expands and contracts, and the electrolyte solution 10 moves due to gravity, causing the gas 20 accumulated in the curved portion 142 to be removed to the outside of the electrode body 140. In FIG. 9, the gas 20 is removed in the direction DR3.

[0052] In this embodiment, the secondary battery 100 is charged and discharged with the electrode assembly 140 tilted 90° from the horizontal. In Figures 8 and 9, the Y and Z directions are horizontal, and the X direction is vertical. The winding axis A of the electrode assembly 140 is aligned with the X direction. The angle at which the electrode assembly 140 is tilted is not limited to 90°, and may be an angle of 45° or more and less than 90°.

[0053] This tilted state allows both ends of the wound electrode body in the direction of the winding axis A to be tilted upward or downward from the horizontal, making it easier for the gas 20 to be removed by the gravity of the electrolyte 10, etc. In this embodiment, the positive electrode side is at the top, but the negative electrode side may also be at the top. Furthermore, when charging and discharging the secondary battery 100, the electrode body 140 may be turned upside down for charging and discharging. This allows the movement of the electrolyte 10 due to gravity to affect both the positive electrode side and the negative electrode side, thereby allowing the gas 20 to be removed uniformly from both the positive electrode side and the negative electrode side of the electrode body 140.

[0054] The current, state of charge (SOC) range, and charge / discharge amount during this charging / discharging process are set based on the relationship between the state of charge (SOC) of a secondary battery and the dimensional change (or load change) that has been obtained in advance for a secondary battery of the same specifications.

[0055] Specifically, the secondary battery 100 according to this embodiment varies in the thickness of the electrode assembly 140 during charging and discharging relative to the state of charge (SOC) of the secondary battery 100, depending on factors such as the graphite stage structure of the negative electrode plate 160. In this embodiment, a predetermined amount or more of thickness change in the electrode assembly 140 is required to remove the gas 20 from inside the electrode assembly 140. If there are no limitations, such as chemical changes or deterioration of the battery material, a range of state of charge (SOC) at which the thickness change of the electrode assembly 140 is large, a high current rate at which the battery does not deteriorate, and a current amount at which the gas can be sufficiently removed are set. The range of state of charge (SOC) at which the thickness change of the electrode assembly 140 is large and a high current rate at which the battery does not deteriorate can efficiently remove the gas 20. It is desirable to set the charge and discharge conditions so that the process of removing the gas 20 from the electrode assembly 140 described above takes a short time.

[0056] In the process of charging and discharging the secondary battery 100, charging and discharging are repeated up to a predetermined state of charge (SOC). In this embodiment, the secondary battery 100 is charged to a state of charge (SOC) of, for example, 50% or less, and then discharged. By repeating this charging and discharging process, the charging time can be shortened compared to charging and discharging at a higher state of charge. The current value during charging is, for example, 30 A. The total charge amount of the secondary battery 100 is, for example, 20 Ah.

[0057] In the process of charging and discharging the secondary battery 100, a load may or may not be applied to the electrode assembly 140.

[0058] 4, the charge / discharge state of the secondary battery 100 is inspected (step S6). Thereafter, the secondary battery 100 is incorporated into a battery module. As described above, in this embodiment, the step of removing the gas 20 from inside the electrode body 140 is performed before the step of inspecting the charge / discharge state of the secondary battery 100.

[0059] Secondary battery 100 in this embodiment is manufactured by pressing electrode body 140 during manufacturing to remove gas 20 from inside electrode body 140, and then tilting winding axis A of electrode body 140 from the horizontal and charging / discharging secondary battery 100. After secondary battery 100 is manufactured, by analyzing the coating unevenness, charging unevenness, and inter-plate dimensions of positive electrode plate 150 and negative electrode plate 160 of electrode body 140 at the center and both ends in the direction of winding axis A, as well as at flat portion 141 and curved portion 142, it can be determined whether secondary battery 100 was charged / discharged with winding axis A of electrode body 140 tilted from the horizontal and then pressed to remove gas 20 from inside electrode body 140. Whether or not a process for removing gas 20 from inside electrode body 140 in this embodiment has been carried out can be confirmed by analyzing, for example, whether there is little charging unevenness or coating unevenness in curved portion 142 (and flat portion 141) after secondary battery 100 is charged, even though the inter-plate dimension of curved portion 142 is larger than that of flat portion 141 of electrode body 140.

[0060] In the method for manufacturing secondary battery 100 according to the first embodiment of the present technology, pressure is applied to electrode body 140 from outside case 120 via the case, removing gas 20 from inside electrode body 140 from both ends in the direction of winding axis A and moving gas 20 to curved portion 142. Thereafter, winding axis A of electrode body 140 is tilted from the horizontal direction, and secondary battery 100 is charged and discharged, thereby removing gas 20 present in curved portion 142 inside electrode body 140. By removing gas 20 from inside electrode body 140, it is possible to suppress uneven coating of electrode body 140, a decrease in battery capacity, an increase in resistance of the secondary battery, or Li deposition, and therefore it is possible to suppress a decrease in performance of secondary battery 100 due to the presence of gas 20 inside electrode body 140.

[0061] In the manufacturing method of the secondary battery 100 according to the first embodiment of the present technology, after pressing the electrode body 140 through the case 120, the secondary battery 100 is charged and discharged with the winding axis A tilted from the horizontal direction. By repeatedly charging and discharging the secondary battery 100, the gas 20 inside the electrode body 140 can be reliably released.

[0062] In the manufacturing method of the secondary battery 100 according to the first embodiment of the present technology, after pressing the electrode body 140 through the case 120, the secondary battery 100 is charged and discharged with the winding axis A tilted from the horizontal direction. By charging the secondary battery 100 to a state of charge (SOC) of 50% or less and then discharging it, the charging time can be shortened compared to when charging and discharging at a higher state of charge, and therefore the process of removing the gas 20 from inside the electrode body 140 can be performed in a short time.

[0063] In the manufacturing method of the secondary battery 100 according to the first embodiment of the present technology, a step of removing gas from inside the electrode body 140 is performed before the step of inspecting the charge / discharge state of the secondary battery 100, thereby reducing the effect of the gas 20 generated inside the case 120 when inspecting the secondary battery 100.

[0064] Hereinafter, a method for manufacturing a secondary battery according to embodiment 2 of the present technology will be described. The method for manufacturing a secondary battery according to this embodiment differs from the method for manufacturing secondary battery 100 according to embodiment 1 of the present technology in the order of steps, and therefore, description of the configuration that is the same as the method for manufacturing secondary battery 100 according to embodiment 1 of the present technology will not be repeated.

[0065] FIG. 10 is a flowchart showing a method for manufacturing a secondary battery according to the second embodiment of the present technology.

[0066] 10, in the method for manufacturing a secondary battery according to this embodiment, the step of removing gas from inside the electrode assembly is performed after the step of inspecting the charge / discharge state of the secondary battery (step S4). Specifically, the step of pressing the electrode assembly through the case from outside the case (step S5), and the step of charging / discharging the secondary battery with the winding axis tilted from the horizontal after pressing the electrode assembly through the case (step S6) are performed after the step of inspecting the charge / discharge state of the secondary battery (step S4).

[0067] In the method for manufacturing a secondary battery according to embodiment 2 of the present technology, the gas generated during the secondary battery manufacturing process can be removed as much as possible by removing the gas inside the electrode body at the end of the secondary battery manufacturing process.

[0068] Compared to a laminated electrode body in which multiple positive and negative electrode plates are stacked, an electrode body in which the openings through which gas can flow are narrow, such as a wound electrode body or a laminated electrode body in which the positive and negative electrode plates are stacked by folding them in a zigzag shape, and it may be difficult for the gas inside the electrode body to be removed to the outside of the electrode body. For this reason, it is particularly effective to apply the manufacturing method of a secondary battery in this embodiment to a secondary battery including a wound electrode body or a laminated electrode body in which the positive and negative electrode plates are stacked by folding them in a zigzag shape.

[0069] Although the embodiments of the present technology have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0070] 2 pressing jig, 10 electrolyte, 20 gas, 100 secondary battery, 110 electrode terminal, 111 positive electrode terminal, 112 negative electrode terminal, 120 case, 121 sealing plate, 122 bottom surface, 123 pair of long side walls, 124 pair of short side walls, 130 gas release valve, 140 electrode body, 141 flat portion, 142 curved portion, 150 positive electrode plate, 151 positive electrode core, 152 positive electrode active material layer, 160 negative electrode plate, 161 negative electrode core, 162 negative electrode active material layer, 170 separator, A winding shaft, F pressing force.

Claims

1. a step of accommodating an electrode assembly in which a positive electrode plate, a separator, and a negative electrode plate are wound around a winding axis, together with an electrolyte, in a case and sealing the case; a step of housing the electrode body and the electrolyte in the case, sealing the case, and then generating gas from the electrode body by charging or heat treatment; A method for manufacturing a secondary battery, comprising a step of removing the gas from inside the electrode body, The step of removing the gas from inside the electrode body includes: pressing the electrode body from outside the case through the case; and then charging and discharging the secondary battery in a state in which the winding axis is tilted from the horizontal direction.

2. 2. The method for manufacturing a secondary battery according to claim 1, wherein the step of charging and discharging the secondary battery includes repeatedly charging and discharging the secondary battery up to a predetermined charge rate.

3. 3. The method for manufacturing a secondary battery according to claim 1, wherein the step of charging and discharging the secondary battery includes charging the secondary battery to a charge rate of 50% or less and then discharging the secondary battery.

4. further comprising a step of inspecting a charge / discharge state of the secondary battery; 3. The method for manufacturing a secondary battery according to claim 1, wherein the step of removing the gas from inside the electrode body is carried out before the step of inspecting the charge / discharge state of the secondary battery.

5. further comprising a step of inspecting a charge / discharge state of the secondary battery; 3. The method for manufacturing a secondary battery according to claim 1, wherein the step of removing the gas from inside the electrode body is carried out after the step of inspecting the charge / discharge state of the secondary battery.

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