JP2013097988A - Battery and method for manufacturing battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a battery which an electrode body can be easily inserted into a battery case when manufactured and suppresses a deterioration in a battery characteristic, and a battery.SOLUTION: A first case wall part 13 for a battery 1 has a shape in which plate thickness TW is gradually reduced more as the plate thickness goes from an end part 13E in a long side direction toward a central part 13C, and in an uninserted battery case body 11B, an electrode body facing plane 14 has a convex shape outward. A method for manufacturing the battery 1 includes: a deformation compression step for pressing the first case wall part with a pressing member 60 outside the battery to make an outside plane 15 thereof convex inward, performing inverse deformation to a state in which the electrode facing plane is brought into the entire contact with an electrode body principal plane SF, and compressing the electrode body 30 in a thickness direction DN through the first case wall part by the pressing member; and a compression continuation processing step for performing compression continuation processing for continuously compressing the electrode body by the first case wall part.

Description

  The present invention relates to a battery including an electrode body and a battery case having a bottomed rectangular box-shaped battery case body, and a method for manufacturing the battery.

In recent years, lithium-ion secondary batteries (hereinafter simply referred to as batteries) that can be charged and discharged have been used as power sources for driving vehicles such as hybrid cars and electric cars.
As such a battery, for example, in Patent Document 1, among the side walls constituting the periphery of the opening of the square case, the ends of the pair of long side walls are thicker than the center part of the long side walls. In this way, the battery unit is disclosed so that the electrode body unit can be accommodated at a correct position in the square case without being tilted.

JP 2009-259450 A

  In the battery described in Patent Document 1, among the inner dimensions formed by the pair of long side walls, the inner dimension between the central portions of the long side walls is larger than the inner dimension between the end portions. It is a form (refer FIG. 5 of patent document 1). For this reason, when manufacturing a battery, it is easy to insert an electrode body unit into a square case through an opening.

  However, in the battery of Patent Document 1, a gap is generated between the central portion of the long side wall and the electrode body unit (electrode body), and a load is applied in the thickness direction of the electrode body between the pair of long side walls. I can't. By the way, when the battery is initially charged, gas may be generated in the electrode body. Then, in the electrode body in which no load is applied in the thickness direction (uncompressed), this gas tends to stay between the positive electrode plate or the negative electrode plate and the separator, and the staying gas is generated between the positive electrode plate and the negative electrode plate. The battery characteristics may be deteriorated because the battery reaction is interrupted.

  The present invention has been made in view of such a problem, and at the time of manufacturing, the electrode body can be easily inserted into the battery case, and a method for manufacturing a battery in which deterioration of battery characteristics is suppressed, and An object is to provide a battery.

  One embodiment of the present invention includes an electrode body having a pair of electrode body main planes orthogonal to its thickness direction, and a pair of electrode body facing surfaces that house the electrode bodies and face the pair of electrode body main planes, respectively. A bottomed rectangular box-shaped battery case main body including a pair of first case wall portions, and a battery case having a sealing lid that seals a rectangular opening of the battery case main body. The first case wall portion is a method of manufacturing a battery in which the whole of the pair of electrode body main planes among the electrode bodies is compressed in the thickness direction, and the pair of first case wall portions are respectively The plate has a shape in which its thickness gradually decreases from the long side direction end portions located on both ends in the long side direction of the opening toward the central portion in the long side direction. The battery case body is inserted before the electrode body is inserted. The front battery case main body has the pair of first case wall portions, the pair of electrode body facing surfaces being convex outward, and the electrode body is inserted into the pre-insertion battery case main body. After the insertion step, after the insertion step, a sealing step of sealing the opening of the battery case body before insertion with the sealing lid, and pressing the pair of first case walls with a pressing member outside the battery, Each of the outer side surfaces is convex inward, and the electrode body facing surface is in contact with the entire pair of electrode body main planes of the electrode body so as to contact each other, and the pressing member causes the first case wall portion to pass through the first case wall portion. A deformation compression process for compressing the electrode body in the thickness direction, and a compression continuation process process for performing a compression continuation process for continuing the compression of the electrode body by the pair of first case wall portions even after the pressing member is removed; With It is a manufacturing method of the pond.

  In the battery manufacturing method described above, in the insertion step, the electrode body facing surfaces of the pair of first case walls are respectively convex outward, that is, the dimension between the pair of electrode body facing surfaces is in the long side direction. Using the battery case body before insertion that gradually increases from the end toward the center, an electrode body is inserted into this. Therefore, the battery can be manufactured by easily inserting the electrode body into the battery case main body (pre-insertion battery case main body).

  And after that, in a deformation | transformation compression process, a pair of 1st case wall part is pressed with a press member, these are reversely deformed, and an electrode body is compressed to a thickness direction with a press member through a 1st case wall part. For this reason, an electrode body can be uniformly compressed in the thickness direction by the electrode body opposing surface of a pair of 1st case wall part which carried out reverse deformation. In addition, by performing the compression continuation process, the pair of first case wall portions that are inverted and deformed continue to compress the electrode body through the electrode body facing surface. Therefore, even if gas is generated in the electrode body, it is easily released to the outside of the electrode body. Thus, a battery is produced in which the gas is interposed between the positive electrode plate or the negative electrode plate and the separator and the battery characteristics are prevented from deteriorating. it can.

  Note that “inverted deformation” of the first case wall portion means that the electrode case-facing surface (first case wall) of the first case wall portion whose thickness gradually decreases from the end in the long side direction toward the center portion. The inner surface of the first part of the first case wall is convex outward, and the opposing surfaces of the electrode bodies are respectively provided on the entire main body plane of the pair of electrode bodies. It means changing to the form of contact. In addition, the battery case body includes one that is “inverted and deformed” by either elastic deformation or plastic deformation.

  In addition, as the “compression continuation process”, for example, the first case wall portion is pressed, and the reverse deformation of the first case wall portion can be maintained on the outer side surface (end portion outer side surface) of the long side direction end portion. The process of forming the uneven | corrugated | grooved part which makes the uneven | corrugated pattern containing several recessed part or convex parts, such as circular shape, polygonal shape, and rod shape, arrange | positioned by forming is mentioned. Moreover, for example, a process of applying plastic deformation to the pair of first case wall parts and a process of sealing the battery case with the internal pressure of the battery case lower than the atmospheric pressure can be cited.

  Further, in the battery manufacturing method described above, the compression continuation process step may be a battery manufacturing method that is a reduced pressure sealing step of sealing after reducing the pressure inside the battery case.

  The compression continuation process step in the battery manufacturing method described above is a reduced pressure sealing step for sealing after reducing the pressure inside the battery case. For this reason, it is possible to manufacture a battery in which the pair of first case wall portions reliably compresses the electrode body through the electrode body facing surface due to the pressure difference between the atmospheric pressure and the internal pressure.

  As a method of “depressurizing the inside of the battery case”, for example, a battery case having a communication hole that communicates the inside and outside of the battery case, such as an electrolyte injection hole, is placed in the vacuum chamber, and the inside of the vacuum chamber is decompressed. Thus, there is a method of reducing the pressure inside the battery case through the communication hole. At this time, the battery case is in a state where the first case wall portion is pressed by the pressing member. Examples of the method of “sealing” include a method of covering the communication hole with a metal member made of metal in a state where the inside of the battery case is decompressed, and fixing the metal member to the battery case by welding or the like. .

  Furthermore, in any one of the above-described battery manufacturing methods, the compression continuation process step maintains the reverse deformation of the first case wall portion generated in the deformation compression step even after the pressing member is removed. And an unevenness forming step of forming an uneven portion for compressing the electrode body on the first case wall portion on an outer surface of the end portion of the long side direction among the outer surfaces of the first case wall portion. A battery manufacturing method is preferable.

  Of the battery manufacturing method described above, the compression continuation processing step includes the above-described unevenness forming step. For this reason, it is possible to manufacture a battery in which the pair of first case wall portions continues to reliably compress the electrode body through the electrode body facing surface.

  Furthermore, according to another aspect of the present invention, an electrode body having a pair of electrode body main planes perpendicular to its own thickness direction and a pair of electrode bodies that house the electrode bodies and face the pair of electrode body main planes, respectively. A bottomed rectangular box-shaped battery case main body including a pair of first case walls forming an electrode body facing surface, and a battery case having a sealing lid that seals a rectangular opening of the battery case main body. In the battery, the pair of first case wall portions has a thickness that is longer than a long side direction end portion of each of the end portions of the first case wall portion located on both ends in the long side direction of the opening. From the form in which the pair of electrode body facing surfaces protrude outwardly from each other, the outer surfaces of the pair of first case wall portions are respectively inward. It becomes convex, and it extends over the entire pair of electrode body main planes of the electrode body. Re the electrode body facing surface is inverted deformed abuts embodiment, a battery formed by compressing the electrode body in the thickness direction by the first case wall portion of the pair.

  The above-mentioned battery is formed by compressing the entire pair of electrode body main planes in the thickness direction by the pair of first case wall portions. For this reason, it can prevent that gas accumulates between the positive electrode plate or negative electrode plate of an electrode body, and a separator, and it can be set as the battery which suppressed the fall of the battery characteristic.

In the battery described above, the plate thicknesses of the pair of first case walls are gradually reduced from the long side direction end toward the center. Further, the pair of first case wall portions has a pair of electrode body facing surfaces that protrude outwardly, respectively, and the outer surfaces of the pair of first case wall portions protrude inward, respectively, and the pair of electrodes of the electrode body The electrode body opposing surface is in contact with the whole body main plane and is inverted and deformed, and the electrode body is compressed in the thickness direction by a pair of first case wall portions. For this reason, a pair of 1st case wall part can compress the whole between electrode body main planes of an electrode body reliably.
In addition, the battery case main body before being reversely deformed has a configuration in which the pair of electrode body facing surfaces are convex outward, that is, the dimension between the pair of electrode body facing surfaces is directed from the end portion in the long side direction toward the center portion. It is the form which is gradually increasing with. For this reason, for example, since the electrode body can be easily inserted into the battery case body at the time of manufacture, the battery can be easily manufactured.

  Furthermore, in the battery described above, the battery case is preferably a battery that is sealed in a state where the internal pressure is lower than atmospheric pressure.

  In the battery described above, the battery case is sealed in a state where the internal pressure of the battery case is lower than the atmospheric pressure. Therefore, due to the pressure difference between the atmospheric pressure and the internal pressure, the pair of first case wall portions causes the electrode body to pass through the electrode body facing surface. The battery can be reliably compressed.

  Furthermore, in the battery according to any one of the above, the battery case includes, on the outer side surface of the first case wall portion, an end portion outer surface of the long side direction end portion of the first case wall portion. It is preferable that the battery has a concavo-convex portion for maintaining the reverse deformation and compressing the electrode body on the first case wall portion.

  In the above-described battery, since the outer side surface of the first case wall has an uneven portion on the outer surface of the end portion, the pair of first case wall portions reliably keeps the electrode body compressed through the electrode body facing surface. be able to.

It is a partial notch perspective view of the battery concerning an embodiment. It is sectional drawing (the AA arrow cross section of FIG.1, 8) of the battery concerning embodiment and a modification. It is sectional drawing (BB sectional view of FIG. 2) of the battery concerning embodiment and a modification. It is explanatory drawing which shows an insertion process among the manufacturing methods of the battery concerning embodiment and a modification. It is a top view of the battery case main body before insertion used for an insertion process. It is explanatory drawing which shows a deformation | transformation compression process among the manufacturing methods of the battery concerning embodiment and a deformation | transformation form. It is explanatory drawing which shows a pressure-reduction sealing process among the manufacturing methods of the battery concerning embodiment. It is a partial notch perspective view of the battery concerning a modification. It is explanatory drawing which shows an uneven | corrugated formation process among the manufacturing methods of the battery concerning a deformation | transformation form.

(Embodiment)
Next, the battery 1 according to the present embodiment will be described with reference to FIGS.
The battery 1 is a lithium ion secondary battery including an electrode body 30 and a battery case 10 that houses the electrode body 30 (see FIGS. 1 to 3). In addition, the battery 1 includes a positive electrode terminal member 41 connected to the positive electrode plate 31 of the electrode body 30 and a negative electrode terminal member 42 connected to the negative electrode plate 32 (see FIGS. 1 and 2).

Of these, the electrode body 30 is formed by winding a belt-like positive electrode plate 31 and a negative electrode plate 32 around a winding axis AX in a flat shape via a belt-like separator 33 made of polyethylene, and has a long cross section PJ. It is a circular flat wound electrode body (see FIG. 1). As shown in FIG. 1, the thickness direction of the electrode body 30 is a minor axis direction DN of an oval cross section PJ.
The strip-shaped positive electrode plate 31 constituting the electrode body 30 includes a positive electrode foil (not shown) made of aluminum and a positive electrode active material layer (not shown) including positive electrode active material particles. The strip-shaped negative electrode plate 32 includes a negative electrode foil (not shown) made of copper and a negative electrode active material layer (not shown) containing negative electrode active material particles.

As shown in FIG. 2, the electrode body 30 is formed by exposing a part of the positive electrode foil forming the positive electrode plate 31 from the separator 33 on one end side in the axial direction DX along the winding axis AX (exposed). Positive electrode foil 31V) and a part of the negative electrode foil forming negative electrode plate 32 are exposed from separator 33 on the other end side in axial direction DX (exposed negative electrode foil 32V).
In the present embodiment, as shown in FIG. 2, the electrode body 30 is placed in a state where the winding axis AX is orthogonal to the case bottom 12 and the sealing lid 21 of the battery case 10 (battery case body 11). It is accommodated in the case 10. In this battery case 10, the exposed positive foil 31 </ b> V of the electrode body 30 is closer to the sealing lid 21, and the exposed negative foil 32 </ b> V is closer to the case bottom 12 of the battery case 10 (battery case body 11). They are located on the side far from the lid 21 (see FIG. 2).

In addition, the electrode body 30 is positioned at both ends of the ellipse-shaped cross section PJ in the major axis direction DM, and the positive electrode plate 31, the negative electrode plate 32, and the separator 33 are each curvedly arranged in an R shape. It has a curved winding part 30R, 30R and a central winding part 30S which is located between these two curved winding parts 30R, 30R and in which the positive electrode plate 31 and the like are all arranged in a flat plate shape (see FIG. 2).
Among these, the outer surface of the central winding part 30S is a pair of central electrode main main planes 30SF and 30SF having a planar shape orthogonal to the thickness direction (minor axis direction) DN of the electrode body 30, as shown in FIG. . These two central electrode body main planes 30SF and 30SF are in close contact with the inner side surface 14 of the first case wall 13 in the battery case 10 (battery case body 11) described below.

  The battery case 10 includes an aluminum battery case body 11 and a sealing lid 21 (see FIGS. 1 and 2). An insulating film (not shown) made of resin and bent in a box shape is interposed between the battery case 10 (battery case body 11) and the electrode body 30.

The sealing lid 21 of the battery case 10 has a rectangular plate shape. The rectangular opening 19 of the battery case body 11 is sealed and welded to the battery case body 11.
The sealing lid 21 includes a first through hole 26 for penetrating the positive terminal member 41 from the inside of the battery case 10 to the outside, and a second through hole for penetrating the negative terminal member 42 from the inside of the battery case 10 to the outside. 27 and a third through hole 29H positioned between the first through hole 26 and the second through hole 27 (see FIG. 2). In addition, between the sealing lid 21 and the positive terminal member 41 in the first through hole 26 and between the sealing lid 21 and the negative terminal member 42 in the second through hole 27, respectively, an insulating resin is used. Insulating members 28 are interposed to insulate each other. The third through hole 29H is closed by a rectangular plate-shaped safety valve 29.

  Further, the sealing lid 21 is welded to the battery case body 11 by welding the sealing lid 21 to the battery case body 10 and then injected with an electrolyte (not shown) into the battery case 10 from the outside. A liquid hole 22 is provided (see FIG. 2). However, in the completed battery 1 shown in FIGS. 1 to 3, the liquid injection hole 22 is sealed. Specifically, a disk-shaped metal member 24 made of aluminum is fixed to the lid surface 21 </ b> F of the sealing lid 21 in a state where the liquid injection hole 22 is covered from the outside of the battery case 10.

  The battery case body 11 has a bottomed rectangular box shape. Specifically, the battery case body 11 has a case bottom 12 that forms the bottom surface of the battery case body 11. Further, from the long side edge 12L of the case bottom 12, the pair of first case walls 13, 13 rising perpendicularly to the case bottom 12, and the short side edge 12S of the case bottom 12, the case bottom 12 has a pair of second case wall portions 17 and 17 rising perpendicularly to 12 (see FIG. 1).

  Among these, the 1st case wall part 13 has the inner surface 14 located in the inner side of the battery case main body 11, and the outer surface 15 located in the outer side of the battery case main body 11 conversely. As shown in FIG. 3, the inner side surfaces 14, 14 of the pair of first case wall portions 13, 13 are in contact with the pair of central electrode body main planes 30SF, 30SF, respectively.

Moreover, the plate | board thickness TW of the 1st case wall part 13 is long side direction from the long side direction edge parts 13E and 13E each located in the both ends side of the long side direction DL of the opening 19 mentioned above among own edge parts. It gradually becomes thinner toward the center portion 13C of the DL (see FIG. 3).
As shown in FIG. 3, the first case wall portion 13 of the battery case body 11 has an inner side surface 14 and an outer side surface 15 both protruding inside the battery case body 11, and the inner side surfaces 14 and 14 are respectively In this embodiment, the electrode body 30 is in contact with the entire pair of central electrode body main planes 30SF and 30SF. In this form, the first case wall portion 13B of the battery case main body 11B (see FIG. 4) before insertion described below is inverted and deformed.

  Next, the pre-insertion battery case body 11B will be described with reference to a perspective view shown in FIG. 4 and a top view thereof (see FIG. 5). The first case wall portion 13B of the battery case main body 11B before insertion has a plate thickness TW from the long side direction end portions 13E and 13E toward the central portion 13C, similarly to the first case wall portion 13 of the battery case main body 11. The thickness gradually decreases with the progress (see FIGS. 4 and 5). However, it differs from the first case wall 13 of the battery case body 11 in the following points. That is, as shown in FIG. 5, the outer surface 15 of the first case wall 13B is a flat surface, while the inner surface 14 is projected outward from the battery case body 11B before insertion (see FIG. 5). 5).

In the battery 1 of the present embodiment, the battery case 10 is sealed with an internal pressure lower than the atmospheric pressure, and the pair of central electrode body main planes 30SF and 30SF of the electrode body 30 are the inner side surfaces of the first case wall portion 13. 14 is compressed by the atmosphere (arrow in FIG. 3). That is, the first case wall 13 of the battery case main body 11 has, for example, a structure for pressing (for example, a structure in which the battery is sandwiched between two plates and a load is applied to the electrode body through the battery case. The electrode body 30 is continuously compressed in the thickness direction DN of the electrode body 30 without depending on a pressing tool or the like.
For this reason, in the electrode body 30, the positive electrode plate 31 or the negative electrode plate 32 and the separator 33 can be brought into close contact with each other in the thickness direction DN. Therefore, the gas generated in the electrode body 30 by charging such as initial charging does not stay between the positive electrode plate 31 or the negative electrode plate 32 and the separator 33 and is easily released to the outside of the electrode body 30.

  As described above, in the battery 1 according to the present embodiment, the entire pair of central electrode body main planes 30SF and 30SF are compressed in the thickness direction DN by the pair of first case walls 13 and 13. For this reason, it can prevent that gas accumulates between the positive electrode plate 31 or the negative electrode plate 32 of the electrode body 30, and the separator 33, and it can be set as the battery 1 which suppressed the fall of the battery characteristic.

  Further, in the battery 1, the plate thickness TW of the pair of first case walls 13 and 13 is gradually reduced from the long side direction end portion 13E toward the central portion 13C. In addition, the pair of first case wall portions 13, 13 has a configuration in which the inner side surfaces 14, 14 protrude outwardly, respectively, and the outer surface 15, 15 of the pair of first case wall portions 13, 13 protrudes inwardly, respectively. Thus, the inner side surfaces 14 and 14 are reversed and deformed so that the entire pair of central electrode main surfaces 30SF and 30SF of the electrode body 30 are in contact with each other, and the pair of first case wall portions 13 and 13 causes the electrode body 30 to move in the thickness direction. Compressed to DN. For this reason, a pair of 1st case wall part 13 and 13 can compress the whole between electrode center 30 main electrode body main plane 30SF and 30SF reliably.

  Further, in the battery case main body 11B before insertion, which is the battery case main body before being inverted and deformed, the dimension between the pair of inner side surfaces 14, 14 gradually increases from the long side direction end portion 13E toward the central portion 13C. It is the form which is doing. For this reason, since the electrode body 30 can be easily inserted into the battery case main body (pre-insertion battery case main body 11B) at the time of manufacturing (in an insertion step described later), for example, the battery 1 can be easily manufactured.

  Further, since the battery case 10 is sealed in a state where the internal pressure is lower than the atmospheric pressure, the pair of first case wall portions 13 and 13 are connected to the electrodes through the inner side surfaces 14 and 14 due to a pressure difference between the atmospheric pressure and the internal pressure. It can be set as the battery 1 which continues compressing the body 30 reliably.

Next, a method for manufacturing the battery 1 according to the present embodiment will be described with reference to the drawings.
First, the electrode body 30 is produced by a known method. Specifically, both of the belt-like positive electrode plate 31 and the negative electrode plate 32 are wound around a cylindrical core material (not shown) together with the two belt-like separators 33 and 33 to form a cylinder having a winding shaft. A wound body (not shown) having a shape was produced. Then, the core material was extracted from the wound body, and the cylindrical surface was crushed from both sides to produce a flat wound electrode body 30 having an oval cross section.

  Thereafter, the positive electrode terminal member 41 is welded to the positive electrode plate 31 of the electrode body 30, and the negative electrode terminal member 42 is welded to the negative electrode plate 32. Then, the positive terminal member 41 is inserted into the first through hole 26 of the sealing lid 21 and the negative terminal member 42 is inserted into the second through hole 27 of the sealing lid 21 through the insulating member 28, and the electrode is connected to the sealing lid 21. The body 30 was fixed (see FIG. 4).

Next, an insertion process in the method for manufacturing the battery 1 according to the present embodiment will be described with reference to FIG.
In this insertion step, first, a battery case body 11B before insertion before the electrode body 30 is inserted is prepared (see FIGS. 4 and 5). In the pre-insertion battery case body 11B, as described above, the plate thickness TW of the first case wall portion 13B is gradually reduced from the long side direction end portions 13E and 13E toward the center portion 13C ( (See FIGS. 4 and 5). Further, the outer side surface 15 of the first case wall portion 13B is a flat surface, while the inner side surface 14 is projected outward from the battery case main body 11B before insertion.
The insulating film (not shown) bent in the box shape described above is arranged inside the battery case main body 11B before insertion, and then the electrode body 30 fixed to the sealing lid 21 is inserted into the battery case main body 11 (see FIG. 4). ).

Next, the sealing step will be described. In this sealing step, after the above-described insertion step, the opening 19 of the battery case body 11 is sealed with a sealing lid 21 to seal the battery case 10. Specifically, after the insertion step, the battery case main body 11 and the sealing lid 21 arranged so as to cover the opening 19 of the battery case main body 11 are joined by laser welding to seal the battery case main body 11. Stopped. Thus, the battery case 10 in which the electrode body 30 was accommodated was completed.
Thereafter, a rectangular plate-shaped safety valve 29 was fixed to the battery case 10 (the lid surface 21F of the sealing lid 21).

  Next, an electrolytic solution (not shown) is injected into the battery case 10. Specifically, the battery case 10 in which the electrode body 30 is housed is housed in a vacuum chamber, and the inside of the vacuum chamber is decompressed. Then, a liquid injection nozzle (not shown) was inserted into the liquid injection hole 22 of the sealing lid 21, and an electrolytic solution (not shown) was injected into the battery case 10 from the liquid injection nozzle. Thereafter, the vacuum chamber was returned to atmospheric pressure, and the battery case 10 was taken out of the vacuum chamber.

Next, the deformation compression process in the method for manufacturing the battery 1 according to the present embodiment will be described with reference to FIG.
In this deformation compression process, two restraint plates 60, 60 made of metal are used. Each of these restraining plates 60 and 60 includes a plate-like portion 61 and a protruding portion 65. Among these, the plate-like portion 61 is a rectangular plate shape having a larger area than the first case wall portion 13 </ b> B of the battery case 10. A through hole 63 is provided in each of the four corner portions 62 of the plate-like portion 61.
Further, the plate-like protruding portion 65 protruding in a rectangular shape from the vicinity of the center of the plate-like portion 61 has a protruding main surface 66 that faces the protruding direction DY. The projecting main surface 66 gradually becomes convex from one pair of both ends (main surface end portion 66E) to the center portion (main surface center portion 66C) of the two pairs of both ends. (See FIG. 6).

In the deformation compression process, the battery case 10 in which the electrode body 30 is housed is sandwiched between the two restraining plates 60 and 60 from both sides in the thickness direction DN, and the pair of first case wall portions 13B and 13B are pressed (FIG. 6). Specifically, the protrusions 65 and 65 of the two restraining plates 60 and 60 are opposed to each other, and the battery case 10 is disposed between them. At this time, of the projecting main surface 66 of the projecting portion 65, the main surface end portion 66E is the long-side direction end portion 13E of the first case wall portion 13B, and the main surface center portion 66C is the first case wall portion 13B. Each was brought into contact with the central portion 13C.
After the battery case 10 is arranged, the bolts BT are inserted and fastened to the plurality of through holes 63 and 63, respectively, the two restraint plates 60 and 60 are connected, and the battery case 10 is connected by the two restraint plates 60 and 60. Hold it.
As a result, the pair of first case walls 13, 13 is formed from the form in which the inner side surfaces 14, 14 are respectively projected outward from the battery case body 11 (see FIG. 5), and the outer side surfaces 15, 15 are respectively The inner side surfaces 14 and 14 are each deformed in an inverted manner by being convex on the inner side and in which the inner side surfaces 14 and 14 are in contact with the entire pair of central electrode main surfaces 30SF and 30SF of the electrode body 30, respectively. At this time, the two restraint plates 60 and 60 compress the electrode body 30 in the battery case 10 in the thickness direction DN via the first case wall portion 13.

Next, in the method for manufacturing the battery 1 according to the present embodiment, the reduced pressure sealing process will be described with reference to FIG.
This decompression sealing step is a step of decompressing the inside of the battery case 10. That is, after the battery case 10 is housed inside the vacuum chamber VC, the inside of the vacuum chamber VC is decompressed. In addition, since the liquid injection hole 22 is not sealed in the battery case 10 at this time, the inside of the battery case 10 is decompressed through the liquid injection hole 22. In addition, as shown in FIG. 7, since the battery case 10 is accommodated in the vacuum chamber VC while being sandwiched between the two restraining plates 60, 60, the pair of first case wall portions 13, 13 has the above-described reverse deformation. The inside of the battery case 10 is depressurized.

After decompression, the injection hole 22 was covered with a disk-shaped metal member 24, and the periphery of the metal member 24 was welded to the battery case 10 (the lid surface 21F of the sealing lid 21) using laser welding. Thereafter, the inside of the vacuum chamber VC was returned to atmospheric pressure, the battery case 10 was taken out, and the two restraining plates 60 and 60 were removed from the battery case 10.
Thus, the battery case 10 is sealed at an internal pressure lower than the atmospheric pressure, and the battery 1 formed by compressing the electrode body 30 in the thickness direction DN by the first case wall portion 13 is completed (see FIGS. 1 to 3).

  As described above, in the insertion step of the manufacturing method of the battery 1, the insertion in the form in which the inner method TN between the pair of inner side surfaces 14 and 14 gradually increases from the long side direction end portion 13E toward the central portion 13C. The front battery case main body 11B is used, and the electrode body 30 is inserted therein. For this reason, the battery 1 can be manufactured by easily inserting the electrode body 30 into the battery case body 11 (battery case body 11B before insertion).

  In addition, in the subsequent deformation and compression process, the pair of first case wall portions 13 and 13 are pressed by the two restraint plates 60 and 60, and these are reversed and deformed by the restraint plate 60 via the first case wall portion. The electrode body 30 is compressed in the thickness direction DN. For this reason, the electrode body 30 can be uniformly compressed in the thickness direction DN by the inner side surfaces 14 and 14 of the pair of first case walls 13 and 13 that are inverted and deformed. In addition, by performing the compression continuation process (in this embodiment, the process of sealing the internal pressure of the battery case 10 in a state lower than the atmospheric pressure), the pair of first case walls 13 and 13 that are inverted and deformed are The electrode body 30 continues to be compressed through the side surfaces 14 and 14. For this reason, even if gas is generated in the electrode body 30, the battery 1 can be easily released to the outside of the electrode body 30, so that the battery 1 can be manufactured in which deterioration of battery characteristics is suppressed.

  Further, the compression continuation processing step is a reduced pressure sealing step for sealing after reducing the pressure inside the battery case 10. For this reason, the battery 1 can be manufactured in which the pair of first case wall portions 13, 13 continues to reliably compress the electrode body 30 through the inner side surfaces 14, 14 due to the pressure difference between the atmospheric pressure and the internal pressure.

(Deformation)
Next, modifications of the present invention will be described with reference to the drawings.
In this modification, the first case wall portion is pressed and arranged on the outer side surface (end portion outer surface) of the long side direction end portion so as to be able to maintain the reverse deformation of the first case wall portion. This is different from the above-described embodiment in that a process of adding a circular recess is performed.
Therefore, differences from the embodiment will be mainly described, and description of similar parts will be omitted or simplified. In addition, about the same part, the same effect is produced. In addition, the same contents are described with the same numbers.

  A battery 101 according to this modification is a lithium ion secondary battery including an electrode body 30 and a battery case 110 that accommodates the electrode body 30 as in the above-described embodiment (see FIGS. 2, 3, and 8). . Among these, the battery case 110 has the battery case main body 111 and the sealing lid 21 similar to embodiment (refer FIG.2, 8).

The battery case body 111 has a bottomed rectangular box shape as in the embodiment described above. Further, in the first case wall portion 113 of the battery case main body 111, the inner side surfaces 14, 14 are in contact with the pair of central electrode body main planes 30SF, 30SF of the electrode body 30, respectively, as in the embodiment. .
Further, the plate thickness TW of the first case wall 113 gradually decreases from the long side direction end portions 113E and 13E toward the central portion 13C in the long side direction DL as in the embodiment (see FIG. 3). In the first case wall 113, as in the embodiment, the inner side surface 14 and the outer side surface 15 are both convex on the inner side of the battery case body 11, and the inner side surfaces 14 and 14 are respectively a pair of central portions of the electrode body 30 The electrode body main planes 30SF and 30SF are in contact with each other.

However, it differs from the embodiment in that each outer surface 15, 15 of the first case wall 113 has a concave portion 70 that is recessed in a circular shape.
Specifically, as shown in FIG. 8, the outer side surface 15 has a plurality of recesses 70 and 70 on an end portion outer surface 15 </ b> E that is an outer surface of the long side direction end portion 13 </ b> E. Since the recess 70 maintains the reverse deformation of the first case wall 113, the first case wall 113 of the battery case main body 111 does not depend on, for example, a pressing structure, and the electrode body 30 is arranged in the thickness direction DN. Continue to compress. Therefore, as in the embodiment, in the electrode body 30, the positive electrode plate 31 or the negative electrode plate 32 and the separator 33 can be brought into close contact with each other in the thickness direction DN.

Thus, in the battery 101 according to the present modified embodiment, since the end portion outer surface 15E has the recess 70 in the outer surface of the first case wall 113, the pair of first case wall portions 113, 113 are the inner surfaces 14,14. Thus, the battery 101 can be reliably compressed through the electrode body 30.
In the battery 101 according to this modification, the battery case 110 is sealed with an internal pressure lower than the atmospheric pressure, and the pair of first case wall portions 113 and 113 each have a recess 70. Therefore, for example, even when gas is generated in the battery case 110 due to charging / discharging of the battery and the internal pressure of the battery case 110 is increased, the recess 70 reliably maintains the reverse deformation of the first case wall portions 113 and 113. be able to.

Next, a method for manufacturing the battery 101 according to this modification will be described with reference to the drawings.
Note that, in the manufacturing method of the battery 101, since the production of the electrode body 30 to the deformation compression process was performed in the same manner as the above-described embodiment, the description thereof is omitted.

Next, of the manufacturing method of the battery 101 according to this modified embodiment, the reduced pressure sealing process will be described with reference to FIGS.
In this decompression sealing process, first, as in the embodiment, after the battery case 110 is housed in the vacuum chamber VC, the inside of the vacuum chamber VC is decompressed and the interior of the battery case 110 is decompressed through the liquid injection hole 22. . Then, after welding the metal member 24 covering the liquid injection hole 22 to the battery case 110 (sealing lid 21), the battery case 110 is taken out from the vacuum chamber VC returned to atmospheric pressure, and the two restraining plates 60 and 60 are connected to the battery case. Removed from 110.

However, the present embodiment is different from the embodiment in that the decompression sealing process of the present modification includes an unevenness forming process for forming the recesses 70 in the battery case 110. Specifically, using the press mold PM shown in FIG. 9, a concave portion 70 that is recessed in a circular shape is formed on the outer side surface 15E of the outer side surface 15 of the battery case 110 from which the restraint plate 60 has been removed.
Thus, the battery case 110 is sealed with an internal pressure lower than the atmospheric pressure, and the end outer surfaces 15E and 15E of the pair of first case walls 113 and 113 have the recesses 70, respectively. The battery 101 formed by compressing the electrode body 30 in the thickness direction DN is formed by the case wall portions 113 and 113 (see FIGS. 2, 3 and 8).

  Of the manufacturing method of the battery 101 according to this modified embodiment, the reduced pressure sealing step includes the above-described unevenness forming step. Therefore, it is possible to manufacture the battery 101 in which the pair of first case walls 113 and 113 continues to reliably compress the electrode body 30 through the inner side surfaces 14 and 14.

In the above, the present invention has been described with reference to the embodiments and modifications. However, the present invention is not limited to the above-described embodiments and the like, and it is needless to say that the present invention can be appropriately modified and applied without departing from the gist thereof. Yes.
For example, in the embodiments and the like, the batteries 1 and 101 including the flat wound electrode body 30 are shown. However, any of them may be a battery including a stacked electrode body in which a flat positive electrode plate, a negative electrode plate, and a separator are stacked in the stacking direction. In this case, in the electrode body, the stacking direction in which the positive plates and the like are stacked is the thickness direction of the electrode body.
Further, in the modification, the battery 101 having the recess 70 in the first case wall portion 113 of the battery case 110 sealed under reduced pressure is shown. However, it is good also as a battery which has a recessed part (uneven | corrugated | grooved part) in the edge part outer surface of a 1st case wall about the battery case of the same pressure inside and outside.

1,101 Battery 10, 110 Battery case 11, 111 Battery case main body 11B Battery case main body 13, 113 before insertion First case wall 13B (first battery case main body) First case wall 13E Long side direction end 13C Central part 14 inner surface (electrode body facing surface)
15 outer surface 15E end outer surface 19 opening 21 sealing lid 30 electrode body 30SF central electrode body main plane (electrode body main plane)
60 Restraint plate (pressing member)
70 Concave part (concave / convex part)
DL (opening) long side direction DN short diameter direction (thickness direction of electrode body)
TW (first case wall) thickness

Claims (6)

An electrode body having a pair of electrode body main planes perpendicular to its thickness direction;
A battery case body having a bottomed rectangular box shape that includes a pair of first case wall portions that house the electrode bodies and form a pair of electrode body facing surfaces that face the pair of electrode body main planes, respectively, and the battery case A battery case having a sealing lid that seals the rectangular opening of the main body, and
A method of manufacturing a battery in which the entire pair of electrode body main planes among the electrode bodies is compressed in the thickness direction by the pair of first case wall portions,
The pair of first case walls are
Each of the plate thicknesses has a shape that gradually decreases from the long-side end located at both ends in the long-side direction of the opening toward the center in the long-side direction. And
Among the battery case bodies, the battery case body before insertion before inserting the electrode body is
Of the pair of first case wall portions, each of the pair of electrode body facing surfaces is convex outwardly,
An insertion step of inserting the electrode body into the battery case body before insertion,
After the insertion step, a sealing step of sealing the opening of the battery case body before insertion with the sealing lid;
The pair of first case wall portions are pressed by a pressing member outside the battery, and the respective outer surfaces thereof are convex inward, and the electrode body facing surfaces are respectively disposed on the entire pair of electrode body main planes of the electrode body. A deformation compression step in which the electrode body is compressed in the thickness direction through the first case wall portion by the pressing member, and reversely deformed into a contact form;
And a compression continuation process step of performing a compression continuation process for continuing the compression of the electrode body by the pair of first case wall portions even after the pressing member is removed. A battery manufacturing method according to claim 1, comprising:
The compression continuation process step includes
A method for producing a battery, which is a reduced pressure sealing step of sealing after reducing the pressure inside the battery case. A method of manufacturing a battery according to claim 1 or claim 2,
The compression continuation process step includes
Even after the pressing member is removed, the first case wall includes an uneven portion for maintaining the reverse deformation of the first case wall portion generated in the deformation compression step and compressing the electrode body on the first case wall portion. The manufacturing method of a battery including the unevenness | corrugation formation process formed in the edge part outer surface of the said long side direction edge part among the said outer surface of a wall part. An electrode body having a pair of electrode body main planes perpendicular to its thickness direction;
A bottomed rectangular box-shaped battery case main body including a pair of first case wall portions that house the electrode bodies and form a pair of electrode body facing surfaces that respectively face the pair of electrode body main planes, and the battery case A battery case having a sealing lid that seals the rectangular opening of the main body,
The pair of first case walls are
Each of the plate thicknesses has a shape that gradually decreases from the long-side end located at both ends in the long-side direction of the opening toward the center in the long-side direction. And
From the form in which the pair of electrode body facing surfaces are respectively convex outward, the outer surfaces of the pair of first case wall portions are convex inward, respectively, and the entire pair of electrode body main planes of the electrode body respectively. A battery formed by reversing and deforming the electrode body facing surface into contact with the electrode body and compressing the electrode body in the thickness direction by the pair of first case wall portions. The battery according to claim 4,
The battery case is
A battery that is sealed with its internal pressure lower than atmospheric pressure. The battery according to claim 4 or 5, wherein
The battery case is
Of the outer side surfaces of the first case wall portion, the reverse deformation of the first case wall portion is maintained on the end outer surface of the end portion in the long side direction, and the electrode body is placed on the first case wall portion. A battery having uneven portions to be compressed.