Battery manufacturing method and battery

Abstract

To provide a manufacturing method for a battery, in which decrease in sealability of a liquid injection frame is suppressed.SOLUTION: A manufacturing method for a battery to achieve the above object includes a preparing step of preparing an electrode member including an electrode multilayer body and a liquid injection frame, a liquid injection step of injecting an electrolyte solution into the electrode multilayer body in the electrode member through the liquid injection frame, a temporarily sealing step of disposing a gas pack for covering an entire outer periphery of the liquid injection frame to temporarily seal the liquid injection frame when viewed from an x-axis direction, which is orthogonal to a z-axis direction, a gas storing step of storing gas generated by charging or aging in an internal space of the gas pack, a degassing step of opening the gas pack to degas, and a sealing step of sealing the liquid injection frame using a sealing member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a battery and the battery. [Background technology]

[0002] It is known that a method for manufacturing batteries such as lithium-ion secondary batteries includes a degassing process to prevent the internal pressure of the battery from increasing due to gas generated during the charging or aging process. Patent Document 1 discloses a method for manufacturing a secondary battery in which a pair of wide sides of a battery case are sandwiched from both sides and the battery case is pressed in the sandwiching direction to perform the charging, degassing, and aging processes in a restrained state. Furthermore, Patent Document 2, for example, discloses providing a pressure adjustment unit on the side of the battery to prevent the internal pressure of the battery from increasing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-021104 [Patent Document 2] Japanese Patent Application Publication No. 2019-016459 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, if gas is generated during the charging process or aging process, the internal pressure of the battery increases. When the internal pressure of the battery increases, gas is more likely to leak from structurally weak parts. Therefore, a degassing process may be performed to prevent the internal pressure of the battery from increasing.

[0005] In order to control the internal pressure of the battery to a low level, for example, it is effective to seal the battery, release the gas after the internal pressure has increased, seal the battery again, release the gas after the internal pressure has increased again, i.e., to repeat the sealing step and the degassing step. On the other hand, if the sealing step and the degassing step are repeated, deformation may occur in the filling frame for pouring the electrolyte or the sealing member, and the sealing ability of the filling frame may decrease.

[0006] The present disclosure has been made in consideration of the above-described circumstances, and a main object of the present disclosure is to provide a battery manufacturing method that suppresses deterioration of the sealing performance of the liquid filling frame. [Means for solving the problem]

[0007] [1] a preparation step of preparing an electrode member having an electrode stack including a plurality of electrodes stacked in the z-axis direction and a resin pouring frame disposed on a side surface of the electrode stack; a liquid injection step of injecting an electrolyte into the electrode stack of the electrode member through the liquid injection frame; a temporary sealing step of, after the liquid filling step, arranging a gas pack so as to cover the entire outer periphery of the liquid filling frame as viewed in an x-axis direction perpendicular to the z-axis direction, and temporarily sealing the liquid filling frame; a gas storing step of storing gas generated by charging or aging in the internal space of the gas pack after the temporary sealing step; a degassing step of opening the gas pack after the gas storing step and degassing the gas; a sealing step of sealing the liquid filling frame with a sealing member after the degassing step; A method for manufacturing a battery having the above structure.

[0008] [2] The method for manufacturing a battery according to [1], wherein the sealing member includes at least one of: (i) a portion of the gas pack that has been cut with a cutting jig and that remains connected to the liquid filling frame; (ii) a portion of the gas pack that has been cut with a cutting jig and that has been separated from the liquid filling frame; and (iii) a member other than the gas pack.

[0009] [3] The method for producing a battery according to [2], wherein the sealing member includes the above (i).

[0010] [4] The method for producing a battery according to [2], wherein the sealing member includes the above (ii).

[0011] [5] The method for producing a battery according to [2], wherein the sealing member includes the above (iii).

[0012] [6] The gas pack has a film member, The method for manufacturing a battery according to [3] or [4], wherein in the sealing step, a stacked portion is formed in which a plurality of the film members are stacked in the x-axis direction.

[0013] [7] The gas pack has a film member, The method for manufacturing a battery according to any one of [1] to [6], wherein the film member has a first resin layer, a metal layer, and a second resin layer in this order in the thickness direction.

[0014] [8] the liquid filling frame includes a resin, The method for manufacturing a battery according to any one of [1] to [7], wherein in the temporary sealing step, the gas pack is welded so as to cover the entire outer periphery of the liquid filling frame.

[0015] [9] the liquid filling frame includes a resin, The method for manufacturing a battery according to any one of [1] to [8], wherein in the sealing step, the sealing member is welded to the opening surface of the liquid filling frame.

[0016]

[10] The electrode stack has a rectangular shape in a plan view, The method for manufacturing a battery according to any one of [1] to [9], wherein the length of one side of the rectangle is 30 cm or more.

[0017]

[11] The method for manufacturing a battery according to any one of [1] to

[10] , wherein the liquid filling frame has a plurality of liquid filling ports in the z-axis direction.

[0018]

[12] The method for manufacturing a battery according to any one of [1] to

[11] , wherein the liquid filling frame has a plurality of liquid filling ports in a y-axis direction perpendicular to the z-axis direction and the x-axis direction.

[0019]

[13] an electrode stack including a plurality of electrodes stacked in the z-axis direction; a resin injection frame disposed on a side surface of the electrode stack; an electrolyte solution impregnated in the electrode stack; a sealing member that seals the liquid filling frame; A battery having a gas pack unit is disposed so as to cover the entire outer periphery of the liquid filling frame when viewed from an x-axis direction perpendicular to the z-axis direction; the gas pack portion has a first surface and a second surface facing each other, the sealing member has a first extending portion extending from the first surface and a second extending portion extending from the second surface; A battery in which a stacked portion in which the first extension portion and the second extension portion are stacked is arranged as viewed from the x-axis direction.

[0020]

[14] The battery according to

[13] , wherein a residual component of the electrolyte is present between the first extension portion and the second extension portion in the laminated portion. [Effects of the Invention]

[0021] The battery manufacturing method according to the present disclosure has the effect of suppressing deterioration of the sealing performance of the liquid filling frame. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic cross-sectional view illustrating an electrode member according to the present disclosure. [Figure 2] FIG. 2 is a schematic perspective view illustrating an example of the liquid filling frame in FIG. [Figure 3] 3A to 3C are schematic cross-sectional views illustrating a temporary sealing step, a gas containing step, a gas venting step, and a sealing step in the present disclosure. [Figure 4] 3A to 3C are schematic cross-sectional views illustrating a temporary sealing step, a gas containing step, and a gas releasing step in the present disclosure. [Figure 5] 5A to 5C are schematic cross-sectional views illustrating a sealing step in the present disclosure. [Figure 6] 1 is a schematic cross-sectional view (exploded view) illustrating a method for producing an electrode stack according to the present disclosure. [Figure 7] 1A to 1C are schematic cross-sectional views illustrating a method for producing an electrode stack according to the present disclosure. [Figure 8] 1A to 1C are schematic cross-sectional views illustrating a method for producing a gas pack according to the present disclosure. [Figure 9] 3A to 3C are schematic cross-sectional views illustrating a degassing step and a sealing step in the present disclosure. [Figure 10] 3A to 3C are schematic cross-sectional views illustrating a degassing step and a sealing step in the present disclosure. [Figure 11] 3A to 3C are schematic cross-sectional views illustrating a degassing step and a sealing step in the present disclosure. [Figure 12] 3A to 3C are schematic cross-sectional views illustrating a degassing step and a sealing step in the present disclosure. [Figure 13] FIG. 1 is a schematic cross-sectional view illustrating a battery according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Each of the drawings shown below is a schematic illustration, and the size and shape of each part are appropriately exaggerated for ease of understanding. Furthermore, in this specification, when expressing the manner in which another member is disposed relative to a certain member, the term "above" or "below" simply refers to both a case in which another member is disposed directly above or below the certain member so as to be in contact with the certain member, and a case in which another member is disposed above or below the certain member via another member, unless otherwise specified.

[0024] A. Battery manufacturing method An example of a battery manufacturing method according to the present disclosure will be described with reference to Figures 1 to 3. Figure 1 is a schematic cross-sectional view illustrating an electrode member according to the present disclosure, Figure 2 is a schematic perspective view illustrating the liquid filling frame in Figure 1, and Figure 3 is a schematic cross-sectional view illustrating the temporary sealing step, gas accommodating step, degassing step, and sealing step according to the present disclosure.

[0025] Fig. 1 is a schematic cross-sectional view illustrating an example of an electrode stack according to the present disclosure. As shown in Fig. 1, an electrode member EM is prepared (preparation step) including an electrode stack 10 including a plurality of electrodes E stacked in the z-axis direction and a resin liquid pouring frame 20 arranged on a side surface SS of the electrode stack 10. Furthermore, the liquid pouring frame 20 shown in Fig. 2 has three liquid pouring ports 21a, 21b, and 21c arranged in the z-axis direction. As shown in Fig. 1, the liquid pouring ports 21a, 21b, and 21c are arranged corresponding to the power generation units U1, U2, and U3, respectively.

[0026] Next, the electrolyte is poured into the electrode stack 10 of the electrode member EM through the pouring frame 20 (pouring step). As shown in Fig. 1, a through-hole 51 that communicates with the inside of the electrode stack 10 is formed in the side surface SS of the electrode stack 10. A nozzle (not shown) is placed in the pouring port 21 of the pouring frame 20, and the electrolyte is poured into the inside of the electrode stack 10 through the through-hole 51.

[0027] Next, as shown in FIG. 3(a), the gas pack 30 is arranged so as to cover the entire outer periphery of the liquid filling frame 20 as viewed from the x-axis direction, and the liquid filling frame 20 is temporarily sealed (temporary sealing step). For example, the liquid filling frame 20 shown in FIG. 2 has surfaces 22a, 22b, 22c, and 22d as surfaces that form the outer periphery in the x-axis direction. The gas pack 30 is welded to these surfaces. In this way, the liquid filling frame 20 is temporarily sealed with the gas pack 30. Thereafter, charging or aging is performed. Gas is generated by charging or aging, and the generated gas is stored in the internal space S of the gas pack 30 (gas storage step). Next, as shown in FIG. 3(b), the gas pack 30 is cut and the gas is released (gas release step). Next, as shown in FIGS. 3(c) to 3(e), the liquid filling frame 20 is sealed using a sealing member X (a portion of the gas pack 30 that has been cut with a cutting jig and remains connected to the liquid filling frame 20) (sealing step).

[0028] Another example of the battery manufacturing method according to the present disclosure will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a schematic perspective view illustrating the temporary sealing step, the gas containing step, and the gas releasing step according to the present disclosure. Fig. 5 is a schematic perspective view illustrating the sealing step according to the present disclosure.

[0029] The liquid filling frame 20 shown in FIG. 4(a) has multiple liquid filling ports 21 in each of the y-axis direction and the z-axis direction, for a total of 12 liquid filling ports 21. The liquid filling frame 20 shown in FIG. 4(a) has surfaces 22a, 22b, 22c, and 22d that form the outer periphery in the x-axis direction. Next, as shown in FIG. 4(b), the gas pack 30 is welded to surfaces 22a to 22d. This temporarily seals the liquid filling frame 20 with the gas pack 30 (temporary sealing process). Thereafter, charging or aging is performed. Gas is generated by charging or aging, and the generated gas is stored in the internal space of the gas pack 30 (gas storage process). Next, as shown in FIG. 4(c), the gas pack 30 is cut in the yz plane and the gas is released (gas release process). Furthermore, cuts C1 to C4 are made in the x-axis direction at the four corners of the gas pack 30 when viewed from the x-axis direction.

[0030] As shown in FIG. 5(a), the portion of the gas pack that covers the entire outer periphery of the infusion frame 20 is referred to as the gas pack portion 31. The gas pack portion 31 has a first surface 31a, a second surface 31b, a third surface 31c, and a fourth surface 31d. The first surface 31a, the second surface 31b, the third surface 31c, and the fourth surface 31d cover the surfaces 22a, 22b, 22c, and 22d in FIG. 4(a), respectively. The first surface 31a and the second surface 31b face each other in the z-axis direction, and the third surface 31c and the fourth surface 31d face each other in the y-axis direction.

[0031] 5(a), an extension portion 32 extending from the gas pack portion 31 is used as a sealing member. The extension portion 32 corresponds to a part of the gas pack 30 that has been cut with a cutting jig and remains connected to the liquid filling frame 20. The extension portion 32 has a first extension portion 32a extending from the first surface 31a, a second extension portion 32b extending from the second surface 31b, a third extension portion 32c extending from the third surface 31c, and a fourth extension portion 32d extending from the fourth surface 31d.

[0032] As shown in FIG. 5(a), the third extension portion 32c and the fourth extension portion 32d are welded onto the opening surface 23 of the liquid filling frame 20 (a surface having the x-axis direction as its normal direction). Next, as shown in FIG. 5(b), the first extension portion 32a is welded to the opening surface 23 of the liquid filling frame 20 via the third extension portion 32c and the fourth extension portion 32d. Next, as shown in FIG. 5(c), the second extension portion 32b is welded to the opening surface 23 of the liquid filling frame 20 via the first extension portion 32a, the third extension portion 32c, and the fourth extension portion 32d. This seals the liquid filling frame 20.

[0033] According to the present disclosure, the use of a gas pack can suppress deterioration of the sealing property of the liquid filling frame. As described above, when gas is generated during the charging process or aging process, the internal pressure of the battery increases. When the internal pressure of the battery increases, gas is more likely to leak from structurally weak parts. Therefore, a degassing process may be performed to prevent the internal pressure of the battery from increasing.

[0034] To control the internal pressure of a battery low, for example, it is effective to seal the battery, release the gas after the internal pressure has increased, seal the battery again, and release the gas after the internal pressure has increased again, i.e., to repeat the sealing and degassing steps. Specifically, repeating the sealing and degassing steps makes it easier to control the internal pressure of the battery lower than the pressure resistance strength of the battery. In particular, for large batteries, the amount of gas generated tends to be large, so repeating the sealing and degassing steps is effective. On the other hand, repeating the sealing and degassing steps may cause deformation of the liquid filling frame or the sealing member (film member) used to fill the electrolyte, which may reduce the sealing ability of the liquid filling frame. Specifically, repeating the operation of heat-welding the sealing member (film member) to the liquid filling frame may easily cause deformation of at least one of the liquid filling frame and the sealing member, which may reduce the sealing ability of the liquid filling frame.

[0035] In contrast, in the present disclosure, a gas pack is used to temporarily seal the liquid filling frame. Because the gas pack has an internal space, it can mitigate the increase in internal pressure of the battery compared to, for example, a case in which a film member is used for temporary sealing. As a result, the need to repeat the sealing process and the degassing process can be eliminated, or the number of times can be reduced. As a result, deformation of at least one of the liquid filling frame and the sealing member is less likely to occur, and deterioration of the sealing performance of the liquid filling frame can be suppressed. Furthermore, as the internal pressure of the battery increases, gas may be forcefully ejected from the through-hole for supplying the electrolyte, and the electrolyte may also be ejected from the through-hole along with the gas flow, causing the electrolyte to splash outside the battery. In contrast, in the present disclosure, a gas pack is used to temporarily seal the liquid filling frame, allowing the gas and electrolyte to be contained within the internal space of the gas pack. As a result, it is possible to prevent the electrolyte from splashing outside the battery. Furthermore, as described below, costs can be reduced by using a portion of the gas pack that is cut by a cutting tool and remains connected to the liquid filling frame as a sealing member.

[0036] 1. Preparation process The preparation process in the present disclosure is a process of preparing an electrode member having an electrode stack including a plurality of electrodes stacked in the z-axis direction and a resin injection frame arranged on the side of the electrode stack.

[0037] (1) Electrode laminate The electrode stack in the present disclosure includes a plurality of electrodes stacked in the z-axis direction. The electrodes have a current collector and an electrode layer (positive electrode layer or negative electrode layer) disposed on at least one surface of the current collector.

[0038] As shown in FIG. 1, the electrode stack 10 includes multiple electrodes E stacked in the z-axis direction. The electrode stack 10 shown in FIG. 1 includes, as electrodes E, bipolar electrodes BP1, BP2, a positive electrode end electrode CA, and a negative electrode end electrode AN. Each of the bipolar electrodes BP1 and BP2 includes a current collector 1, a positive electrode layer 2 disposed on one side of the current collector 1, and a negative electrode layer 3 disposed on the other side of the current collector 1. The positive electrode end electrode CA includes the current collector 1 and the positive electrode layer 2 disposed on one side of the current collector 1. The negative electrode end electrode AN includes the current collector 1 and the negative electrode layer 3 disposed on one side of the current collector 1.

[0039] As shown in FIG. 1 , the electrode laminate 10 may have, as an electrode E, a bipolar electrode BP having a current collector 1, a positive electrode layer 2 disposed on one surface of the current collector 1, and a negative electrode layer 3 disposed on the other surface of the current collector 1. The electrode laminate in the present disclosure may have only one bipolar electrode BP, or may have two or more bipolar electrodes BP. On the other hand, the electrode laminate in the present disclosure is not particularly limited as long as it includes multiple electrodes E stacked in the z-axis direction, and may not have a bipolar electrode.

[0040] As shown in FIG. 1, the electrode stack 10 includes power generation units U (U1 to U3). Each power generation unit U includes a positive electrode layer 2, a negative electrode layer 3, and a separator 4 disposed between the positive electrode layer 2 and the negative electrode layer 3. An electrolyte solution is supplied to the positive electrode layer 2, the negative electrode layer 3, and the separator 4 via through-holes 51. As a result, the positive electrode layer 2, the negative electrode layer 3, and the separator 4 are each impregnated with the electrolyte solution. The electrode stack of the present disclosure may include one power generation unit, or two or more power generation units.

[0041] As shown in FIG. 1, the electrode stack 10 may have a plurality of power generating units U (U1, U2, U3) stacked in the z-axis direction. As shown in FIG. 1, the plurality of power generating units U (U1, U2, U3) may be directly connected to one another. Although not specifically shown, the plurality of power generating units may also be connected in parallel to one another. The plurality of power generating units are independent of one another so that the electrolyte does not flow between them. In FIG. 1, the plurality of power generating units U (U1, U2, U3) are independent of one another so that the electrolyte does not flow between them. For example, the power generating unit U1 and the power generating unit U2 are separated by a current collector 1 and a sealing member 5 and are independent of one another.

[0042] One power generating unit may be constructed using two bipolar electrodes. In FIG. 1, the electrode stack 10 has bipolar electrodes BP1 and BP2 in the z-axis direction. A separator 4 is disposed between adjacent bipolar electrodes BP1 and BP2. The power generating unit U2 is constructed from a positive electrode layer 2 in the bipolar electrode BP2, a negative electrode layer 3 in the bipolar electrode BP1, and a separator 4 disposed therebetween. The power generating unit U1 is constructed from a positive electrode layer 2 in the bipolar electrode BP1, a negative electrode layer 3 in the negative end electrode AN, and a separator 4 disposed therebetween. The power generating unit U3 is constructed from a negative electrode layer 3 in the bipolar electrode BP2, a positive electrode layer 2 in the positive end electrode CA, and a separator 4 disposed therebetween.

[0043] As shown in FIG. 1, a frame-shaped sealing member 5 is preferably disposed along the outer edge of the current collector 1 when viewed from the z-axis direction. The sealing member is preferably a resin member. Examples of resins constituting the resin member include thermoplastic resins. Examples of thermoplastic resins include olefin-based resins such as polyethylene and polypropylene. Furthermore, as shown in FIG. 1, the sealing member 5 preferably has through-holes 51 for supplying an electrolyte solution to the inside of the electrode stack 10. As shown in FIG. 1, the through-holes 51 preferably extend in the x-axis direction.

[0044] The planar shape of the electrode laminate (shape as viewed from the z-axis direction) is not particularly limited, but examples include quadrilaterals such as squares and rectangles. The length of one side of the planar shape of the electrode laminate is, for example, 30 cm or more, or may be 50 cm or more, or may be 100 cm or more. On the other hand, the length of one side is, for example, 200 cm or less.

[0045] The method for producing the electrode laminate is not particularly limited. Fig. 6 is a schematic cross-sectional view (exploded view) illustrating a method for producing an electrode laminate in the present disclosure. As shown in Fig. 6, a bipolar electrode BP1 and a bipolar electrode BP2 are prepared. The bipolar electrode BP1 has a positive electrode layer 2 disposed on one surface of a current collector 1 and a negative electrode layer 3 disposed on the other surface of the current collector 1.

[0046] Furthermore, the bipolar electrode BP1 has a frame member 5a for forming a sealing member, which is arranged along the outer edge of the current collector 1. When viewed from the z-axis direction, the frame member 5a is usually arranged along the entire outer periphery of the current collector 1. For example, if the outer edge of the current collector 1 has a rectangular shape, the frame member 5a is arranged along the entire outer edge of the rectangle. As shown in FIG. 6 , the frame member 5a preferably covers a portion of one main surface p of the current collector 1, a portion of the other main surface q of the current collector 1, and the entire side surface r that constitutes the outer edge of the current collector 1.

[0047] 6, the bipolar electrode BP2 has a positive electrode layer 2 disposed on one surface of the current collector 1 and a negative electrode layer 3 disposed on the other surface of the current collector 1. The bipolar electrode BP2 also has a frame member 5b for forming a sealing member disposed along the outer edge of the current collector 1. Details of the bipolar electrode BP2 are the same as those of the bipolar electrode BP1 described above.

[0048] As shown in FIG. 6, the negative electrode layer 3 of the bipolar electrode BP1 and the positive electrode layer 2 of the bipolar electrode BP2 are opposed to each other with a separator 4 interposed therebetween. At this time, at least a portion of the outer edge of the separator 4 is disposed between the frame members 5a and 5b. Also, as shown in FIG. 6, a nest 6 and a frame member (spacer) 5c are disposed between the frame member 5a of the bipolar electrode BP1 and the frame member 5b of the bipolar electrode BP2. Next, although not specifically shown, a positive end electrode CA and a negative end electrode AN are laminated on the bipolar electrodes BP1 and BP2, respectively, with the separator 4 interposed therebetween, as in FIG. 1. Then, the laminated frame members are welded together to form a sealing member. In this manner, an electrode stack with the nest inserted is obtained.

[0049] (2) Filling frame The liquid pouring frame in the present disclosure is disposed on a side surface of the electrode stack. The side surface of the electrode stack refers to a surface of the electrode stack extending in the z-axis direction. The side surface of the electrode stack is usually a surface connecting the top surface (one main surface) and the bottom surface (the other main surface) of the electrode stack, which are opposed to each other in the z-axis direction.

[0050] The liquid filling frame is made of a resin. Examples of the resin that constitutes the liquid filling frame include thermoplastic resins. Examples of the thermoplastic resin include olefin-based resins such as polyethylene and polypropylene.

[0051] As shown in FIG. 2, the liquid filling frame 20 has a liquid filling port 21. The liquid filling port 21 is a portion that allows the electrolyte to be supplied in the x-axis direction, which is perpendicular to the z-axis direction. Also, as shown in FIG. 2, the liquid filling frame 20 may have multiple liquid filling ports 21 (21a, 21b, 21c) arranged in the z-axis direction. On the other hand, although not specifically shown, the liquid filling frame may have only one liquid filling port. Also, as shown in FIG. 4(a), the liquid filling frame 20 may have multiple liquid filling ports 21 arranged in the y-axis direction. Similarly, the liquid filling frame 20 in FIG. 4(a) may have multiple liquid filling ports 21 arranged in the z-axis direction.

[0052] The peripheral shape of the filling port as viewed from the x-axis direction is not particularly limited, but examples thereof include quadrilaterals such as a rectangle and a square. The peripheral shape of the filling frame as viewed from the x-axis direction is not particularly limited, but examples thereof include quadrilaterals such as a rectangle and a square. As shown in FIG. 2, the filling frame 20 may have surfaces 22a, 22b, 22c, and 22d as surfaces constituting the periphery as viewed from the x-axis direction. A gas pack, described below, is welded to these surfaces. In FIG. 2, surfaces 22a and 22b are arranged opposite each other. Similarly, in FIG. 2, surfaces 22c and 22d are arranged opposite each other.

[0053] (3) Electrode materials The electrode member according to the present disclosure has an electrode stack including a plurality of electrodes stacked in the z-axis direction, and a resin pouring frame disposed on a side of the electrode stack. The method for producing the electrode member is not particularly limited. FIG. 7 is a schematic cross-sectional view illustrating an example of a method for producing the electrode member according to the present disclosure. As shown in FIG. 7( a), first, an electrode stack 10 having an insert 6 inserted therein is prepared. In the electrode stack 10, one end t1 of the insert 6 is located inside the electrode stack 10, and the other end t2 of the insert 6 is located outside the electrode stack 10.

[0054] Next, as shown in FIG. 7(b), a liquid pouring frame 20 made of resin is placed on the side surface SS of the electrode stack 10. The liquid pouring port 21 of the liquid pouring frame 20 is positioned so as not to interfere with the other end t2 of the insert 6. For example, the liquid pouring frame 20 may be fixed to the side surface SS of the electrode stack 10 by welding the liquid pouring frame 20 to the side surface SS of the electrode stack 10. Alternatively, the liquid pouring frame 20 may be placed on the side surface SS of the electrode stack 10 by resin molding such as injection molding.

[0055] 2. Liquid injection process The liquid injection step in the present disclosure is a step of injecting an electrolyte solution into the electrode stack of the electrode member through the liquid injection frame. The method of injecting the electrolyte solution is not particularly limited, and for example, a known method using a liquid injection device is used. The electrolyte solution is introduced into a liquid injection port (e.g., liquid injection port 21 in FIG. 1) and supplied into the electrode stack through a through-hole (e.g., through-hole 51 in FIG. 1).

[0056] 3.Temporary sealing process The temporary sealing step in the present disclosure is a step of temporarily sealing the liquid filling frame by arranging a gas pack so as to cover the entire outer periphery of the liquid filling frame when viewed from the x-axis direction perpendicular to the z-axis direction after the liquid filling step.

[0057] The gas pack preferably has a film member. The film member preferably has a metal layer. The film member having a metal layer improves gas barrier properties. As will be described later, when a part of the gas pack is used as a sealing member, the film member preferably has a metal layer. Examples of materials for the metal layer include aluminum, aluminum alloys, and stainless steel. The thickness of the metal layer is, for example, 30 μm or more and 60 μm or less. On the other hand, when a part of the gas pack is not used as a sealing member, high gas barrier properties are not required, and therefore the film member does not need to have a metal layer.

[0058] The film member preferably has a resin layer. The film member having a resin layer improves adhesion to the resin filling frame. When the gas pack is arranged so as to cover the entire periphery of the filling frame, it is preferable to weld the resin layer of the gas pack to the filling frame. Examples of materials for the resin layer include thermoplastic resins. Examples of thermoplastic resins include olefin-based resins such as polyethylene and polypropylene, and ester-based resins such as polyethylene terephthalate. The film member may have only one or two or more resin layers, or may have a resin layer and a metal layer.

[0059] The film member preferably has a first resin layer, a metal layer, and a second resin layer in this order in the thickness direction. The first resin layer improves adhesion to the resin filling frame, the metal layer improves gas barrier properties, and the second resin layer improves insulation properties. The first resin layer preferably contains an olefin-based resin such as polyethylene or polypropylene. The thickness of the first resin layer is, for example, 40 μm or more and 100 μm or less. The material and thickness of the metal layer are as described above. The second resin layer preferably contains an ester-based resin such as polyethylene terephthalate. The thickness of the second resin layer is, for example, 40 μm or more and 100 μm or less.

[0060] The gas pack is preferably made of a film material. For example, as shown in FIG. 8(a), the film material is folded to form a hollow member 30' having a rectangular outer edge in cross section in the x-axis direction. Next, two midpoints in the z-axis direction are designated as P1 and P2 on one end face of the hollow member 30' in the x-axis direction. The midpoints P1 and P2 are each pressed toward the center of the end face, and in this state, heat and pressure are applied from the z-axis direction. This results in a gas pack 30 as shown in FIG. 8(b).

[0061] For example, as shown in FIG. 3, the gas pack 30 has an internal space S that can accommodate gas generated by charging or aging. By having the internal space S, an increase in the internal pressure of the battery due to the gas is suppressed. The maximum volume of the internal space S is not particularly limited, but it is possible to provide, for example, 200 cm for one filling port. 3 More than 1000cm 3 is less than or equal to 500cm 3 More than 900cm 3 or less. Furthermore, the volume (apparent volume) of the internal space of the gas pack with the liquid filling frame temporarily sealed may be smaller than the maximum volume of the internal space. For example, if the gas pack with the liquid filling frame temporarily sealed is folded or if the gas pack with the liquid filling frame temporarily sealed is warped, the volume (apparent volume) of the internal space of the gas pack with the liquid filling frame temporarily sealed will be smaller than the maximum volume of the internal space. In this case, the volume (apparent volume) of the internal space will increase due to gas generated by charging or aging.

[0062] As shown in FIG. 4(b), the gas pack 30 is disposed so as to cover the entire outer periphery of the liquid filling frame 20 when viewed from the x-axis direction. The liquid filling frame 20 has surfaces 22a, 22b, 22c, and 22d that form the outer periphery in the x-axis direction. The gas pack 30 is disposed on these surfaces, and the liquid filling frame 20 is temporarily sealed. Surfaces 22a and 22b face each other in the z-axis direction, and surfaces 22c and 22d face each other in the y-axis direction.

[0063] The gas pack in the present disclosure does not generally correspond to an exterior body that covers the entire electrode member. This is because the electrolyte solution impregnated inside the electrode laminate is basically sealed by a sealing member (e.g., sealing member 5 in FIG. 1) and a current collector (current collector 1 in FIG. 1). Furthermore, when an exterior body that covers the entire electrode member is used, if the electrode member becomes larger, the exterior body also needs to be larger. In contrast, when the electrolyte solution impregnated inside the electrode laminate is sealed by a sealing member (e.g., sealing member 5 in FIG. 1) and a current collector (current collector 1 in FIG. 1), there is no need to use an exterior body that covers the entire electrode member, which has the advantage that the electrode member can be easily made larger.

[0064] 4.Gas storage process The gas storage step in the present disclosure is a step of storing gas generated by charging or aging in the internal space of the gas pack after the temporary sealing step. When the electrode member (battery) after the temporary sealing step is charged or aged, gas is generated due to, for example, decomposition of the electrolyte, and the internal pressure of the electrode member (battery) increases. As the internal pressure increases, the gas spontaneously diffuses through the through hole (e.g., through hole 51 in FIG. 1) toward the liquid inlet (e.g., liquid inlet 21 in FIG. 1) and is stored in the internal space of the gas pack.

[0065] The conditions for charging or aging are not particularly limited. Regarding the charging conditions, for example, charging may be performed until the SOC (State of Charge) reaches 50% or more, 70% or more, or 90% or more. Meanwhile, the aging temperature may be, for example, 35°C or more and 85°C or less, or may be 40°C or more and 80°C or less. The aging time may be, for example, 10 hours or more, 20 hours or more.

[0066] 5. Gas removal process The gas release step in the present disclosure is a step of opening the gas pack and releasing the gas after the gas storing step. Examples of a method for opening the gas pack include cutting the gas pack and drilling a hole in the gas pack.

[0067] 3(a), the gas pack 30 may be cut to release the gas contained in the internal space of the gas pack 30. Alternatively, although not particularly shown, the gas pack may be perforated to release the gas contained in the internal space of the gas pack, and then the gas pack may be appropriately cut in accordance with the processing to be performed in the sealing step described below.

[0068] 6. Sealing process The sealing step in the present disclosure is a step of sealing the liquid filling frame with a sealing member after the degassing step. The sealing step is preferably performed in a reduced pressure atmosphere.

[0069] The sealing member preferably includes at least one of (i) a portion of the gas pack that has been cut by the cutting jig and remains connected to the liquid filling frame, (ii) a portion of the gas pack that has been cut by the cutting jig and separated from the liquid filling frame, and (iii) a member other than the gas pack.

[0070] First, the above-mentioned case (i) will be described. In the above-mentioned case (i), the liquid filling frame is sealed using a sealing member including a portion of the gas pack that has been cut with a cutting jig and remains connected to the liquid filling frame. For example, as shown in FIG. 3(a), when the gas pack 30 is cut with a cutting jig (not shown), a portion of the gas pack 30 remains connected to the liquid filling frame 20 as shown in FIG. 3(b). The remaining gas pack 30 is used as a sealing member X to seal the liquid filling frame 20 as shown in, for example, FIGS. 3(c) and 3(d). Specifically, as shown in FIG. 3(c), the first extension portion 32a is heat-welded to the opening surface β of the liquid filling frame 20 using, for example, a heat bar. Next, as shown in FIG. 3(d), the second extension portion 32b is heat-welded to the first extension portion 32a using, for example, a heat bar. As a result, as shown in FIG. 3(e), a stacked portion α is formed in which multiple film members (first extension portion 32a and second extension portion 32b) are stacked in the x-axis direction. Residual components of the electrolyte may be present between the first extension portion 32a and the second extension portion 32b. In the gas containing step described above, not only gas but also electrolyte is contained in the internal space of the gas pack. Therefore, residual components of the electrolyte may be present between the first extension portion 32a and the second extension portion 32b.

[0071] 5, as in FIG. 3, extension portion 32 extending from gas pack portion 31 is used as a sealing member. Extension portion 32 has first extension portion 32a extending from first surface 31a, second extension portion 32b extending from second surface 31b, third extension portion 32c extending from third surface 31c, and fourth extension portion 32d extending from fourth surface 31d. In the present disclosure, it is preferable that a stacked portion α is formed in which at least two of first extension portion 32a, second extension portion 32b, third extension portion 32c, and fourth extension portion 32d are stacked in the x-axis direction.

[0072] In the present disclosure, the liquid filling frame may be sealed without forming the laminated portion described above. For example, as shown in FIGS. 9(a) and 9(b), the gas pack 30 is cut with a cutting jig (not shown) to form only the first extension portion 32a as the extension portion 32. Next, as shown in FIG. 9(c), the first extension portion 32a is welded onto the opening surface β of the liquid filling frame 20. This seals the liquid filling frame 20 without forming the laminated portion described above, as shown in FIG. 9(d). In this case, the third extension portion and fourth extension portion described above may also be cut with the cutting jig.

[0073] In the present disclosure, the liquid filling frame may be sealed without welding the extension portion to the opening surface of the liquid filling frame. For example, as shown in FIGS. 10(a) and 10(b), the gas pack 30 is cut using a cutting jig (not shown) to form a first extension portion 32a and a second extension portion 32b. Next, as shown in FIG. 10(c), the first extension portion 32a and the second extension portion 32b are welded to face each other in the z-axis direction. As a result, as shown in FIG. 10(d), the liquid filling frame 20 is sealed without welding the extension portion 32 to the opening surface β of the liquid filling frame 20. Note that in FIG. 10(c), it is preferable to press the third extension portion and the fourth extension portion toward the center of the end surface, as in FIG. 8 described above.

[0074] Next, the above-mentioned case (ii) will be described. In the above-mentioned case (ii), the liquid filling frame is sealed using a sealing member including a portion of the gas pack cut with a cutting jig and separated from the liquid filling frame. For example, as shown in FIG. 11(a), when the gas pack 30 is cut with a cutting jig (not shown), a portion of the gas pack 30 is separated from the liquid filling frame 20 as shown in FIG. 11(b). The separated gas pack 35 is used as a sealing member X to seal the liquid filling frame 20 as shown in, for example, FIGS. 11(c) and 11(d). Specifically, as shown in FIG. 11(c), the gas pack 35 is welded onto the opening surface β of the liquid filling frame 20. As a result, the liquid filling frame 20 is sealed by the gas pack 35 as shown in FIG. 11(d).

[0075] In the present disclosure, the above (ii) and (i) may be combined. For example, as shown in FIG. 12(a), when the gas pack 30 is cut with a cutting jig (not shown), a portion of the gas pack 30 remains connected to the liquid filling frame 20, as shown in FIG. 12(b). The remaining gas pack 30 is used as the sealing member X. Furthermore, by the above cutting, a portion of the gas pack 30 is separated from the liquid filling frame 20. The separated gas pack 35 is also used as the sealing member X. Specifically, as shown in FIG. 12(c), the gas pack 35 is welded onto the opening surface β of the liquid filling frame 20. Next, as shown in FIG. 12(d), the first extension portion 32a and the second extension portion 32b are welded so as to face each other in the z-axis direction. As a result, the liquid filling frame 20 is sealed with the sealing member X, as shown in FIG. 12(e).

[0076] Next, the case of (iii) above will be described. In this case, a member other than a gas pack is used as the sealing member X to seal the liquid filling frame. The member other than a gas pack may be, for example, a film member. Details of the film member are the same as those of the film member constituting the gas pack described above, and therefore will not be described here. Furthermore, as a specific example of using a member other than a gas pack, a member other than a gas pack (for example, a film member) may be used instead of the "gas pack 35" shown in FIGS. 11 and 12 above. In the present disclosure, the above (iii) and the above (i) may be combined. In the present disclosure, the above (i), the above (ii), and the above (iii) may be combined.

[0077] 7.Battery The battery in the present disclosure is preferably a secondary battery (e.g., a lithium-ion secondary battery). Examples of uses for the battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. It is particularly preferred that the battery be used as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The battery in the present disclosure may also be used as a power source for mobile objects other than vehicles (e.g., trains, ships, and aircraft), or as a power source for electrical appliances such as information processing devices.

[0078] B.Battery FIG. 13 is a schematic cross-sectional view illustrating a battery according to the present disclosure. The battery 100 shown in FIG. 13 includes an electrode stack 10 including multiple electrodes E stacked in the z-axis direction, a resin-made liquid filling frame 20 arranged on the side of the electrode stack 10, an electrolyte (not shown) impregnated in the electrode stack 10, and a sealing member X that seals the liquid filling frame 20. As shown in FIG. 5(c), a gas pack unit 31 is arranged to cover the entire outer periphery of the liquid filling frame 20 when viewed from the x-axis direction. The gas pack unit 31 has a first surface 31a and a second surface 31b that face each other. In FIG. 5(c), the sealing member has a first extension portion 32a extending from the first surface 31a and a second extension portion 32b extending from the second surface 31b. When viewed from the x-axis direction, a stacked portion α is arranged in which the first extension portion 32a and the second extension portion 32b are stacked.

[0079] According to the present disclosure, the arrangement of the predetermined laminated portion α results in a battery that suppresses deterioration of sealing performance due to deformation of the liquid filling frame. Details of the battery according to the present disclosure are the same as those described above in "A. Battery Manufacturing Method." For example, the sealing member may have a third extension portion 32c and a fourth extension portion 32d.

[0080] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within the technical scope of the present disclosure. [Explanation of symbols]

[0081] 1...Current collector 2...Positive electrode layer 3...Anode layer 4...Separator 5...Sealing material 10... Electrode laminate 20...Filling frame 30...Gas pack 100...battery

Claims

1. a preparation step of preparing an electrode member including an electrode stack including a plurality of electrodes stacked in the z-axis direction and a resin pouring frame disposed on a side surface of the electrode stack; a liquid injection step of injecting an electrolyte into the electrode stack of the electrode member through the liquid injection frame; a temporary sealing step of, after the liquid pouring step, arranging a gas pack having an internal space so as to cover the entire outer periphery of the liquid pouring frame as viewed in an x-axis direction perpendicular to the z-axis direction, and temporarily sealing the liquid pouring frame; a gas containing step of containing gas generated by charging or aging in the internal space after the temporary sealing step, thereby increasing the volume of the internal space; a degassing step of opening the gas pack and degassing the gas after the gas storing step; a sealing step of sealing the liquid filling frame with a sealing member after the degassing step; A method for manufacturing a battery having the above structure.

2. 2. The method for manufacturing a battery according to claim 1, wherein the sealing member includes at least one of: (i) a portion of the gas pack that has been cut with a cutting jig and that remains connected to the liquid filling frame; (ii) a portion of the gas pack that has been cut with a cutting jig and that has been separated from the liquid filling frame; and (iii) a member other than the gas pack.

3. The method for manufacturing a battery according to claim 2 , wherein the sealing member includes the (i).

4. The method for manufacturing a battery according to claim 2 , wherein the sealing member includes (ii).

5. The method for manufacturing a battery according to claim 2 , wherein the sealing member includes the (iii).

6. The gas pack has a film member, The method for manufacturing a battery according to claim 3 or 4, wherein in the sealing step, a stacked portion is formed in which a plurality of the film members are stacked in the x-axis direction.

7. The gas pack has a film member, The method for manufacturing a battery according to claim 1 , wherein the film member has a first resin layer, a metal layer, and a second resin layer in this order in a thickness direction.

8. the liquid filling frame includes a resin, The method for manufacturing a battery according to claim 1 , wherein the gas pack is welded to cover the entire outer periphery of the liquid filling frame in the temporary sealing step.

9. the liquid filling frame includes a resin, The method for manufacturing a battery according to claim 1 , wherein the sealing step comprises welding the sealing member to an opening surface of the liquid filling frame.

10. The electrode stack has a rectangular shape in a plan view, The method for manufacturing a battery according to claim 1 , wherein the length of one side of the rectangle is 30 cm or more.

11. The method for manufacturing a battery according to claim 1 , wherein the liquid filling frame has a plurality of liquid filling ports in the z-axis direction.

12. The battery manufacturing method according to claim 1 , wherein the liquid filling frame has a plurality of liquid filling ports in a y-axis direction perpendicular to the z-axis direction and the x-axis direction.

13. an electrode stack including a plurality of electrodes stacked in the z-axis direction; a resin injection frame disposed on a side surface of the electrode stack; an electrolyte solution impregnated in the electrode stack; a sealing member that seals the liquid filling frame; A battery having a gas pack unit is disposed so as to cover the entire outer periphery of the liquid filling frame when viewed from an x-axis direction perpendicular to the z-axis direction; the gas pack portion has a first surface and a second surface facing each other, the sealing member has a first extending portion extending from the first surface and a second extending portion extending from the second surface; A battery in which a stacked portion in which the first extension portion and the second extension portion are stacked is arranged when viewed from the x-axis direction.

14. The battery according to claim 13 , wherein a residual component of the electrolyte is present between the first extension portion and the second extension portion in the laminated portion.

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