Manufacturing method of battery and the battery

Abstract

To facilitate an attachment of an auxiliary jig and improve workability.SOLUTION: A battery includes: a cell stack; an elastic body disposed at both ends of the cell stack in a stacking direction; a restraining plate disposed at both ends of the elastic body in the stacking direction; an inner plate disposed inside the restraining plate; and a restraining tool that presses two restraining plates in a direction toward each other. The restraining plate is provided with an auxiliary jig through hole which a bolt for attaching an auxiliary jig is passed through an end surface in a direction orthogonal to the stacking direction, and an internal plate through hole which the bolt for attaching the internal plate to the restraining plate is passed through each of both ends of the end surface so as to sandwich the auxiliary jig through hole, and the internal plate is fastened to the restraining plate by the bolt penetrating through the internal plate through hole.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Patent Document 1 discloses that a load is applied to the cell by a restraining plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-091947 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional technology, the restraint plate would bend, making it difficult to fasten auxiliary jigs, such as jigs for injecting liquid, to the restraint plate with bolts.

[0005] Therefore, an object of the present disclosure is to provide a method for manufacturing a secondary battery that allows for easy attachment of an auxiliary jig and improves workability, and also to provide a battery for that purpose. [Means for solving the problem]

[0006] As described above, in the prior art, the restraint plate bends, making it difficult to fasten auxiliary jigs, such as those used for liquid injection, to the restraint plate with bolts. This is specifically explained below. Figure 5 shows an explanatory diagram. Although Figure 5 is a side view, hatching has been added to make it easier to distinguish between components.

[0007] As can be seen in Figure 5, a cell stack is formed by alternately stacking battery cells, which are single cells, and conductive plates. Elastic bodies are placed on both ends of the cell stack in the stacking direction, and constraining plates are stacked on the outside of these. The restraint plates are formed larger than the cell stack and the elastic body, and are fastened at their large protruding portions with restraint devices (through bolts and nuts) located at both ends in the stacking direction, sandwiching and fixing the cell stack and the elastic body between the two restraint plates. The restraint plates have auxiliary jig holes on their end faces for attaching auxiliary jigs.

[0008] Here, because the restraint plate is fastened and restrained by the restraining device, it deflects as shown in Fig. 5. This deflection changes the position of the auxiliary jig fixing holes compared to before the deflection, causing misalignment, which makes it more time-consuming to fix the auxiliary jig to the restraint plate and reduces workability. In response to this, the present disclosure improves workability by making it easier to attach and fix the auxiliary jig to the auxiliary jig fixing holes even when the restraint plate deflects.

[0009] The present application discloses a method for manufacturing a battery, the battery having a cell stack, elastic bodies arranged at each end of the cell stack in the stacking direction, constraint plates arranged at both ends of the elastic bodies in the stacking direction, an internal plate arranged inside the constraint plate, and a constraint device that presses the two constraint plates in a direction bringing them closer together, the constraint plate having an auxiliary jig through hole through which a bolt for attaching the auxiliary jig is passed to an end face in a direction perpendicular to the stacking direction, and internal plate through holes through which bolts for attaching the internal plate to the constraint plate are passed, at each end of the end face on either side of the auxiliary jig through hole, the internal plate being fastened to the constraint plate by a bolt that passes through the internal plate through hole, the manufacturing method comprising the steps of attaching the auxiliary jig to the battery by fastening the auxiliary jig to the internal plate with the bolt that passes through the auxiliary jig through hole while restraining the cell stack via the constraint plate with the constraint device, and then injecting an electrolyte into the battery from the auxiliary jig.

[0010] The present disclosure also discloses a battery having a cell stack, elastic bodies arranged at both ends of the cell stack in the stacking direction, restraint plates arranged at both ends of the elastic bodies in the stacking direction, an internal plate arranged inside the restraint plate, and a restraining device that presses the two restraint plates in a direction bringing them closer together, wherein the restraint plate has an auxiliary jig through-hole through which a bolt is passed to attach an auxiliary jig to the end face in a direction perpendicular to the stacking direction, and internal plate through-holes at both ends of the end face on either side of the auxiliary jig through-hole through which a bolt is passed to attach the internal plate to the restraint plate, and the internal plate is fastened to the restraint plate by a bolt that passes through the internal plate through-hole. [Effects of the Invention]

[0011] According to the present disclosure, even if the restraint plate bends, the internal plate makes it difficult for the screw holes for fixing the auxiliary jig to become misaligned, thereby improving the workability of attaching the auxiliary jig. [Brief explanation of the drawings]

[0012] [Figure 1] 1(a) and 1(b) are perspective views that schematically show the appearance of a secondary battery 10. FIG. [Figure 2] 2(a) is a view of FIG. 1(a) as seen from the y-axis direction, and FIG. 2(b) is a view of FIG. 1(b) as seen from the y-axis direction. [Figure 3] FIG. 3(a) is an enlarged view of a portion of FIG. 1(a), and FIG. 3(b) and FIG. 3(c) are portions of cross sections extracted from FIG. 3(a). [Figure 4] FIG. 4(a) is an external perspective view of the secondary battery 10 to which the auxiliary jig 50 is attached, and FIG. 4(b) and FIG. 4(c) are partial cross-sections extracted from FIG. 4(a). [Figure 5] FIG. 5 is a diagram illustrating an example of the structure of a conventional battery. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. For clarity, some repeated reference numerals may be omitted. The drawings also show the corresponding directions of a three-dimensional Cartesian coordinate system (x-axis, y-axis, z-axis).

[0014] 1. Structure of secondary batteries First, the structure of a secondary battery according to one example of the present disclosure will be described. FIG. 1 is a schematic perspective view of a secondary battery 10 according to this example. FIG. 2 is a side view seen from the direction along the y-axis indicated by A in FIG. 1. Although FIG. 2 is a side view, some components are hatched to make them easier to distinguish. Note that for the sake of explanation, the internal plate 20 is shown separated in FIG. 1(b) and FIG. 2(b). The secondary battery 10 can be used as a battery mounted on a vehicle such as a hybrid vehicle or an electric vehicle. The secondary battery 10 includes a cell stack 11, electrode terminals 14a and 14b, an elastic body 15, a restraining plate 16, an internal plate 20, and a restraining member 30.

[0015] 1.1. Cell stack 11 The cell stack 11 is formed by alternately stacking a plurality of unit cells 12 and a plurality of conductive plates 13 in the z-axis direction. The number of times the stacking is repeated is set appropriately depending on the required battery capacity, the space for arranging the secondary battery, etc. Both ends of the cell stack 11 in the stacking direction are made into conductive plates 13.

[0016] The unit cell 12 is a flat-plate-shaped cell that is thinner in the z-axis direction than in the x-axis and y-axis directions. The specific form of the unit cell 12 is not particularly limited, and known cells can be used. For example, a cell in which multiple bipolar electrodes are stacked can be used. In the case of a unit cell equipped with bipolar electrodes, a current collector, a positive electrode active material layer provided on one surface of the current collector, and a negative electrode active material layer provided on the other surface of the current collector are considered as one unit, and multiple such units are stacked with a separator sandwiched between them, and a sealing member is disposed on the outer peripheral edge.

[0017] The conductive plate 13 is electrically connected to the electrodes that constitute the unit cells 12, and electrically connects two unit cells 12 that are arranged with the conductive plate 13 in between. Here, adjacent unit cells 12 are connected in series by the conductive plate 13. A flow path (not shown) for circulating a cooling medium such as air may be provided inside the conductive plate 13. By circulating a cooling medium through the flow path in the conductive plate 13, the conductive plate 13 also functions as a heat exchanger that discharges heat generated in the unit cells 12 to the outside.

[0018] 1.2. Electrode terminal The electrode terminals 14a, 14b are conductive members that function as the positive and negative terminals of the secondary battery 10. The electrode terminal 14a is electrically connected to the conductive plate 13 that serves as the positive electrode, and the connecting member 14b is electrically connected to the conductive plate 13 that serves as the negative electrode. The electrode terminals 14a, 14b are formed, for example, from a metal material or an alloy material. Examples of metal materials include copper, aluminum, titanium, and nickel. Examples of alloy materials include stainless steel and alloys of the above metal materials.

[0019] 1.3.Elastic Body Elastic body 15 is a sheet-like member made of an electrically insulating material with a low elastic modulus, and its elastic deformation absorbs part of the deformation of restraint plate 16, thereby increasing the uniformity of the restraint force. There are no particular restrictions on the specific material, but examples include rubber and resin. The elastic bodies 15 are laminated on both ends of the cell laminate 11 in the lamination direction (z-axis direction).

[0020] 1.4.Restraint plate In this embodiment, the restraint plate 16 is a box-shaped (hollow plate-shaped) member with a plate-like outer shape, and is made of, for example, metal. Examples of metal materials that make up the restraint plate 16 include alloys such as copper, aluminum, titanium, nickel, and stainless steel. In this embodiment, the restraint plate 16 is a box-shaped member, but is not limited to this and may be a solid plate. However, even in this case, a space is formed in which the internal plate 20 is attached, as will be described later. The restraint plates 16 are arranged to sandwich the cell stack 11 from both sides in the stacking direction (z-axis direction) via the elastic bodies 15. As can be seen from Figures 1 and 2, the outer peripheral edge of the restraint plate 16 significantly protrudes in the x-axis direction relative to the cell stack 11 and elastic bodies 15. A restraint device 30 is placed on this protruding portion.

[0021] Furthermore, of the end faces of the restraint plate 16 (the faces that constitute the thickness of the plate, the faces that include the z-axis direction within the face, and the faces that are perpendicular to the stacking direction), the face to which the auxiliary jig 50 is attached has holes through which mounting fixtures (bolts) are passed. Specifically, an inner plate through-hole 17 and an auxiliary jig through-hole 18 are provided.

[0022] Auxiliary jig through-hole 18 is a hole through which bolt 51 (see FIG. 4(c)) for attaching auxiliary jig 50, which will be described later, to restraint plate 16 passes, and is formed to be larger in diameter than the body and threaded portion of bolt 51. Since restraint plate 16 in this embodiment is a box body, auxiliary jig through-hole 18 is provided so as to penetrate one wall of the box body from the inside to the outside of the box. The arrangement and number of auxiliary jig through holes 18 may be determined depending on the form of auxiliary jig 50. In this embodiment, as an example, eight auxiliary jig through holes 18 are provided in total, with four holes equally spaced apart in the x-axis direction, with two holes arranged in the z-axis direction for each x-axis position.

[0023] The internal plate through-hole 17 is a hole through which a bolt 28 (see FIGS. 3 and 4) passes for attaching the internal plate 20, which will be described later, to the inside of the restraint plate 16, and is formed to have a diameter larger than the diameter of the body and threads of the bolt 28. Since the restraint plate 16 in this embodiment is a box body, the internal plate through-hole 17 is provided so as to penetrate one wall of the box body from the inside to the outside of the box. The internal plate through holes 17 are provided at positions (i.e., two positions) near both ends in the width direction (the direction perpendicular to the thickness direction, the x-axis direction) of the end face of the restraint plate 16 on which the auxiliary jig through holes 18 are provided. It is preferable that all of the auxiliary jig through holes 18 are arranged between the two internal plate through holes 17 in the width direction.

[0024] 1.5.Inner Plate As can be seen from Figures 1(b) and 2(b), the internal plate 20 is a plate-like member that extends in a long, narrow strip shape. As will be described later, the internal plate 20 is disposed inside the restraint plate 16, and is disposed so as to overlap the inner surface of the wall of the restraint plate 16 in which the internal plate through-hole 17 and the auxiliary jig through-hole 18 are provided. Therefore, the internal plate 20 is shaped to fit along the inner surface of the wall of the restraint plate 16, is long in the x-axis direction, and is plate-like with its front and back surfaces aligned in the xz plane.

[0025] Furthermore, the inner plate 20 is formed with auxiliary jig screw holes 22 that penetrate in the thickness direction (y-axis direction) and have female threads so that bolts 51 for attaching the auxiliary jig 50 can be threadedly engaged therewith. The auxiliary jig screw holes 22 are configured to be threadedly engaged with the bolts 51. The positions and number of the auxiliary jig screw holes 22 are set so as to overlap with the auxiliary jig through holes 17 described above.

[0026] Furthermore, the internal plate 20 is formed with internal plate screw holes 21 that penetrate through the internal plate 20 in its thickness direction (y-axis direction) and are threaded so that bolts 28 for fixing the internal plate 20 to the inside of the restraint plate 16 can be threadedly engaged with the internal plate screw holes 21. The internal plate screw holes 21 are configured so that the bolts 28 can be threadedly engaged with the internal plate screw holes 21, and the positions and number of the internal plate screw holes 21 are arranged to overlap with the internal plate through holes 17 described above.

[0027] The internal plate 20 is attached to the restraint plate 16, for example, as follows. An explanatory diagram is shown in Figure 3. Figure 3(a) is an enlarged view of the portion indicated by B in Figure 1, Figure 3(b) is a cross-sectional view in the xy plane taken along the line indicated by C in Figure 3(a), and Figure 3(c) is a cross-sectional view in the xy plane taken along the line indicated by D in Figure 3(a). 2 and 3, the internal plate 20 is placed inside the restraint plate 16, with the plate surface of the internal plate 20 overlapping the inner surface of the restraint plate 16. Then, bolts 28 are passed through the internal plate through holes 17 from the outside of the end face of the restraint plate 16 and screwed into the internal plate screw holes 21. In this way, the internal plate 20 is fixed to the inside of the restraint plate 16 by the bolts 28 at two locations near both ends in the longitudinal direction (x-axis direction).

[0028] As can be seen from FIG. 3(c), the screw hole 22 for the auxiliary jig in the inner plate 20 and the through hole 18 for the auxiliary jig in the restraint plate 16 are arranged to overlap so as to communicate with the inside and outside of the restraint plate 16.

[0029] 1.6.Restraints The restraining device 30 is a member that applies pressure to the two restraining plates 20 in a direction that brings them closer together, and presses and restrains the cell stack 11 and the elastic body 15 that are arranged between the two restraining plates 20. The specific form of the restraining device 30 is not particularly limited, but in this form the restraining device 30 has a block 31, a bolt 32, and a nut 33.

[0030] The block 31 is a rectangular parallelepiped block that is long in one direction (the y-axis direction). The block 31 is provided with holes that penetrate in the z-axis direction, and a plurality of these holes are provided at predetermined intervals along the longitudinal direction of the block 31. The bolt 32 is a bolt with a long shaft. The nut 33 is a nut that is screwed onto the threaded portion of the bolt 32 .

[0031] In this embodiment, the restraint device 30 is arranged as follows. 1 and 2, the blocks 31 are arranged on the surface of the constraining plate 16 opposite the side on which the cell stack 11 is arranged. In this embodiment, two blocks 31 are arranged on each constraining plate 16, one at each end of the constraining plate 16 in the x-axis direction. In this case, the longitudinal direction of the blocks 31 is aligned with the y-axis direction, and the holes are oriented to penetrate in the z-axis direction. As described above, this position is where the constraining plate 16 significantly protrudes from the cell stack 11 and the elastic body 15. The bolt 32 is passed through a hole in the block 31 so as to cross over to the block 31 on the opposite side in the z-axis direction (a hole is also provided in a corresponding position on the restraint plate 16), and a nut 33 is fitted to the threaded portion of the bolt 32. Tightening the bolts 32 generates a restraining force between a pair of restraint plates 16 arranged on opposite sides in the z-axis direction, and the cell stack 11 and elastic body 15 arranged between them are restrained by a predetermined pressing force.

[0032] 2. Secondary battery manufacturing (attaching auxiliary jigs) A description will now be given of an embodiment in which an auxiliary jig is attached to the secondary battery 10 described above during the manufacture thereof. An example of the auxiliary jig is a jig for a liquid injection device that injects an electrolyte solution into the cell stack 11. Fig. 4 shows a scene in which an auxiliary jig 50, which is part of the liquid injection device, is attached to a secondary battery 10 and electrolyte is injected. Fig. 4(a) is a perspective view of the scene in which the auxiliary jig 50 is attached, taken from the same perspective as Fig. 1(a), Fig. 4(b) is a part of a cross section in the xy plane along the line indicated by E in Fig. 4(a), and Fig. 4(c) is a part of a cross section in the xy plane along the line indicated by F in Fig. 4(a). As can be seen in Figure 4, the auxiliary jig 50 is positioned so as to overlap the end face of the restraint plate 16. Bolts 51 are passed through the auxiliary jig 50 and auxiliary jig through-holes 18 from the outside of the auxiliary jig 50 and screwed into the auxiliary jig screw holes 22. This fixes the auxiliary jig to the restraint plate 16 with the bolts 51. Then, with the auxiliary jig 50 attached in this manner, electrolyte is injected into the cell stack 11. That is, while the cell stack 11 is restrained by the restraint device 30 via the restraint plate 16, the auxiliary jig 50 is attached to the secondary battery 10 by fastening the auxiliary jig 50 to the inner plate 20 with the bolts 51 passing through the auxiliary jig through-holes 18, and then electrolyte is injected into the secondary battery 20 from the auxiliary jig 30. Here, the attachment of the auxiliary jig 50 in the manufacturing method of the secondary battery has been described, but the other steps in the manufacturing method of the secondary battery are well known.

[0033] 2. Effects etc. The structure of the secondary battery 10 and the manufacturing method of the secondary battery described above make it easy to attach the auxiliary jig 50, and improve work efficiency. As mentioned in the section on problems with the conventional technology (see Figure 5), the restraining device previously caused the restraint plate to bend, which changed the position of the holes for fixing the auxiliary jig, making it difficult to attach the auxiliary jig. In the secondary battery structure and manufacturing method using the secondary battery according to the present disclosure, as can be seen from Fig. 2(a), although the restraining device 30 causes the restraint plate 16 to bend in the same manner as in the conventional method, the inner plate 20 does not bend, or at least the bending is suppressed to a smaller degree than that of the restraint plate 16. This is because the inner plate 20 is fixed only at both ends of the restraint plate 16, which are the portions of the restraint plate 16 that are least prone to bending. Furthermore, the restraint plate 16 is provided with auxiliary jig through-holes 18 that can communicate with the auxiliary jig screw holes 22 provided in the inner plate 20 located inside it even when the restraint plate 16 is bent. Therefore, even when the restraint plate 16 is bent, the bolts 51 for fixing the auxiliary jig can be easily screwed into the auxiliary jig screw holes 22 provided in the inner plate 20. [Explanation of symbols]

[0034] 10... secondary battery, 11... module stack, 15... elastic body, 16... restraining plate, 20... internal plate, 30... restraining device

Claims

1. A method for manufacturing a battery, comprising: The battery includes a cell stack, elastic bodies arranged at both ends of the cell stack in the stacking direction, constraint plates arranged at both ends of the elastic bodies in the stacking direction, an internal plate arranged inside the constraint plates, and a constraint tool that presses the two constraint plates in a direction that brings them closer together, The restraint plate is provided with an auxiliary jig through-hole through which a bolt for attaching an auxiliary jig to an end face in a direction perpendicular to the stacking direction is passed, and inner plate through-holes through which bolts for attaching the inner plate to the restraint plate are passed, at both ends of the end face so as to sandwich the auxiliary jig through-hole, the inner plate is fastened to the restraint plate by a bolt passing through the inner plate through-hole, The manufacturing method includes: a step of fastening the auxiliary jig to the internal plate with bolts that pass through the auxiliary jig through-holes while restraining the cell stack via the restraint plate with the restraint tool, thereby attaching the auxiliary jig to the battery; Thereafter, the electrolyte is injected into the battery from the auxiliary jig. How batteries are manufactured.

2. a cell stack; an elastic body disposed on each end of the cell stack in the stacking direction; Constraint plates arranged on both ends of the elastic body in the stacking direction; an inner plate disposed inside the restraint plate; a restraining tool that presses the two restraining plates in a direction in which they approach each other, the restraint plate is provided with an auxiliary jig through-hole through which a bolt is passed to attach an auxiliary jig to an end face in a direction perpendicular to the stacking direction, and inner plate through-holes through which bolts are passed to attach the inner plate to the restraint plate at both ends of the end face so as to sandwich the auxiliary jig through-hole, The inner plate is fastened to the restraint plate by a bolt passing through the inner plate through-hole. battery.

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