Flat wound electrode body, battery, battery module, and method for manufacturing flat wound electrode body and battery
Patent Information
- Application Number
- JP2024173300
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-10-02
- Publication Date
- 2025-02-25
- Estimated Expiration
- 2042-01-12
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a battery in which a positive electrode plate, a negative electrode plate, and a pair of separators each having a strip shape are wound in a flat shape. A method for manufacturing a flat wound electrode body, a method for manufacturing a battery including the flat wound electrode body, and a method for manufacturing the battery including the flat wound electrode body The present invention relates to a method for manufacturing a battery module having a battery. [Background technology]
[0002] Conventionally, a battery electrode assembly is formed by a strip-shaped positive electrode plate, a strip-shaped negative electrode plate, and a pair of strip-shaped separators. A flat wound electrode body is known, which is wound flatly through a wire. It is manufactured as follows: a strip-shaped positive electrode plate, a strip-shaped separator, a strip-shaped negative electrode plate, a strip-shaped separator ... The separators are stacked in this order and wound into a cylindrical shape to form a cylindrical wound electrode body. This cylindrical wound electrode body is pressed and flattened to form a flat wound electrode body. In addition, the wound electrode body has a negative electrode plate that is longer than the positive electrode plate, and a separator that is further longer than the negative electrode plate. After the positive electrode plate is wound, the negative electrode plate is wound, and then the separator is wound. As related prior art, for example, Patent Document 1 (See FIGS. 1 and 2 of Patent Document 1, etc.) [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-059395 Summary of the Invention [Problem to be solved by the invention]
[0004] When pressing the cylindrical wound electrode body, the components constituting the cylindrical wound electrode body (positive electrode plate The circumferential position of the winding end terminal of the negative electrode plate and the pair of separators, The circumferential position of the positive electrode terminal of the positive plate, which is hidden inside by the separator, is not considered. Therefore, when setting the cylindrical wound electrode body in the press device, Depending on the arrangement, the circumferential position of the positive electrode terminal end of the completed flat wound electrode body may change. That is, the positive electrode terminal end was located in the flat part (positive electrode plate, negative electrode plate and When a flat wound electrode assembly is manufactured, the electrode assembly is located within the area where the separators are stacked in a flat plate shape. In some cases, the R parts (positive and negative plates) located on both sides of the flat part of the flat wound electrode body and a flat wound electrode body located within the area where the separators are stacked while being bent into a semi-cylindrical shape. were sometimes produced.
[0005] However, the positive electrode terminal end portion is less likely to bend than the middle portion of the positive electrode plate in the longitudinal direction. When the positive electrode terminal end is located within the R portion of the flat wound electrode body, the positive electrode terminal end is lifted up. The positive electrode terminal end and the opposing portion of the negative electrode plate that is located radially inside the positive electrode terminal end and faces the negative electrode plate. The distance between the positive and negative plates tends to become large, and the distance between the positive and negative plates becomes uneven near the positive terminal end. It turns out that it's easy to become one.
[0006] The present invention has been made in view of the above situation, and is directed to suppressing the lifting of the positive electrode terminal end portion. The flat winding prevents the distance between the positive and negative plates from becoming uneven near the positive electrode end. Method for manufacturing a flat wound electrode body, a method for manufacturing a battery including the flat wound electrode body, and a method for manufacturing a battery including the flat wound electrode body A method for manufacturing a battery module in which a plurality of batteries, each including an electrode assembly, are stacked and constrained is provided. [Means for solving the problem]
[0007] In order to solve the above problem, one aspect of the present invention is a battery comprising a pair of strip-shaped positive electrode plates and strip-shaped negative electrode plates. A method for manufacturing a flat wound electrode body in which a strip-shaped separator is interposed between the electrodes, the method comprising: The positive electrode plate and the negative electrode plate are wound into a cylindrical shape with the pair of separators interposed therebetween to form a cylindrical wound electrode. a winding step of forming a cylindrical wound electrode body, and a rolling step of pressing and crushing the cylindrical wound electrode body to form the flat wound electrode body. and a pressing step of forming a positive electrode terminal end at the end of winding of the positive electrode plate. A method for manufacturing a flat wound electrode body, in which pressing is performed so that the flat portion is positioned within the flat portion of the flat wound electrode body. It is a manufacturing method.
[0008] In the above-described method for manufacturing a flat wound electrode body, after pressing, the positive electrode terminal portion of the positive electrode plate is The cylindrical wound electrode body is pressed so that it is positioned within the flat portion of the body, thereby forming a flat wound electrode body. As a result, in any flat wound electrode body to be manufactured, the positive electrode terminal portion of the positive electrode plate is flat. Since it can be placed in the flat part of the flat wound electrode body, the positive electrode terminal The lifting of the ends is suppressed, and the distance between the positive and negative plates near the positive terminal end is uneven. It can prevent this from happening.
[0009] Furthermore, in the method for manufacturing the flat wound electrode body, the winding step includes winding a periphery of the positive electrode terminal end portion. The winding direction of the first separator is the last of the pair of separators to be wound. The cylindrical winding is arranged so that the circumferential position of the end of the rotor is in a predetermined circumferential positional relationship with the end of the rotor. The electrode body is formed, and the pressing step presses the cylindrical wound electrode body so that the terminal end portion of the first separator is pressed against the cylindrical wound electrode body. The flattening machine is placed in a position where the circumferential position of the flattening machine is a predetermined circumferential position. This may be a method for manufacturing a wound electrode body.
[0010] In a wound electrode assembly, the positive electrode plate is usually arranged so that the entire plate faces the negative electrode plate via a separator. The negative plate is longer than the positive plate, and the positive and negative plates are securely insulated from each other. Therefore, the pair of separators are longer than the negative electrode plates. In the cylindrically wound electrode body, the positive electrode terminal of the positive electrode plate is hidden inside the cylindrically wound electrode body. In many cases, it is not possible to see the outside of the pole body in the radial direction. It is often difficult to identify the circumferential position of the positive electrode terminal end from the appearance of the electrode assembly.
[0011] In contrast, in the above-described manufacturing method, first, in the winding process, the positive electrode terminal end portion of the positive electrode plate is wound in the circumferential direction. and the circumferential position of the terminal end of the first separator that is wound last are predetermined. The cylindrical wound electrode body is formed so that the circumferential positional relationship is determined as set forth above. The angle from the end of the separator to the end of the first separator is +180 degrees, or +150 to +210 degrees. Examples include keeping the level within a certain range. In the pressing step, the circumferential position of the terminal end of the first separator is set to a predetermined circumferential position. The cylindrical wound electrode body is placed in the position where it will be placed, and pressed to press the positive electrode terminal end into the flat wound electrode. The terminal end of the first separator is located at the outermost periphery of the cylindrical wound electrode assembly. Therefore, the circumferential position of the terminal end of the first separator can be easily seen from the outside in the radial direction. By using this as a reference, the positive electrode terminal end can be easily and reliably positioned within the flat portion of the flat wound electrode body. .
[0012] In another embodiment, a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are disposed in a circumferential direction via a pair of strip-shaped separators. A method for manufacturing a battery including a flat wound electrode body wound in a flat shape, an electrode body manufacturing process for manufacturing the flat wound electrode body by a method for manufacturing an electrode body; a battery assembly step of assembling the battery using the electrode body. .
[0013] As a result of the investigation by the inventors, it was found that the positive electrode terminal portion of the positive electrode plate was disposed within the R portion of the flat wound electrode body. In a battery, as it is used, the negative electrode plate may become clogged near the positive electrode terminal end. The electrode terminals are located radially inside the opposing parts, and the electrode moves between the plates to initiate the battery reaction. The metal ions that carry the charge are reduced and the metal (e.g., Li in lithium-ion secondary batteries) is precipitated. I found it to be easy to get out. The reason for this is that, as mentioned above, when the positive electrode terminal end is located within the R portion of the flat wound electrode body, In this case, the positive electrode terminal portion is lifted up, and the distance between the positive electrode terminal portion and the above-mentioned opposing portion of the negative electrode plate becomes large. As a result, the resistance in this area increases locally, and the negative electrode potential decreases locally. The potential may be lower than the metal deposition potential (e.g., Li deposition potential). It is thought that metal deposition such as Li deposition occurs near the opposing portions of the electrode plates.
[0014] In contrast, in the above-mentioned battery manufacturing method, the flat wound The electrode assembly is used to assemble the battery. Therefore, in any battery manufactured, the positive electrode The floating of the electrode end portion is suppressed, and the distance between the positive and negative electrodes near the positive end portion is not uniform. Therefore, in both batteries, the positive terminal of the negative electrode plate Metal deposition such as Li deposition occurs near the opposing parts located on the radial inside of the part. can be suppressed.
[0015] The term "battery" refers to a battery in which the above-mentioned flat wound electrode body is housed in a metal battery case. and batteries in which a flat wound electrode body is housed in a battery case made of laminated film. In the battery, the flat portion of the flat wound electrode body and the battery case are connected directly or The flat part of the flat wound electrode body and the battery case may be in close contact with each other via an insulating film or the like. There may be a gap between them.
[0016] Furthermore, in the method for manufacturing the battery, the battery includes: The flat portion is sandwiched between the pair of main side surfaces. a flat battery case that houses the flat wound electrode body; The manufacturing process of the battery includes a step of housing the flat wound electrode body in the flat battery case. It is a good idea to use this as a manufacturing method.
[0017] In the battery manufactured by the above manufacturing method, the flat portion of the flat wound electrode body is connected to a pair of flat battery cases. Therefore, the positive terminal end of the positive plate is pressed from the outside. This effectively prevents the positive electrode terminal from lifting up, This can further suppress the above-mentioned metal deposition caused by the contact.
[0018] In another embodiment, a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are disposed in a circumferential direction via a pair of strip-shaped separators. A plurality of batteries each having a flat wound electrode body wound in a flat shape are stacked in the thickness direction of the battery and restrained. The flat portions of the flat wound electrode bodies of each battery are restrained from the outside in the stacking direction by the a manufacturing method of a battery module in which the electrode body is compressed in the thickness direction, a battery manufacturing step of manufacturing the battery by a method, and a step of disposing a plurality of the batteries in the battery thickness direction. The flat wound electrodes of each battery are stacked, and are restrained from the outside in the stacking direction by the restraining portion. The flat portions of the battery body are compressed in the thickness direction of the electrode body, and the battery module is assembled. and a module assembly process.
[0019] In the above-mentioned manufacturing method of the battery module, the battery manufactured by the above-mentioned manufacturing method is used. Therefore, in this battery module, all the components included therein are In all batteries, metal deposition caused by the lifting of the positive electrode terminal end of the positive plate was suppressed. Furthermore, in this battery module, each battery is constrained, and the flat portions of the flat wound electrode bodies are The electrode body is compressed in the thickness direction. Therefore, the positive electrode terminal is pressed from the outside. , the lifting of the positive electrode terminal part can be more effectively suppressed, This can further suppress metal deposition caused by the above.
[0020] The "battery module" may be, for example, a battery module in which multiple batteries are directly stacked and restrained by a restraining portion. and battery modules in which multiple batteries are stacked alternately with spacers interposed and restrained by restraint sections. Battery modules and the like. [Brief explanation of the drawings]
[0021] [Figure 1] 1 is a simplified cross-sectional view of a flat wound electrode body according to an embodiment, taken perpendicular to the electrode body axis direction. [Figure 2] FIG. 1 is a perspective view of a battery according to an embodiment. [Figure 3] FIG. 2 is a side view of the battery module according to the embodiment. [Figure 4]4 is a flowchart of a battery module manufacturing process including manufacturing a flat wound electrode body and a battery according to an embodiment. [Figure 5] FIG. 4 is an explanatory diagram of a winding step according to the embodiment. [Figure 6] FIG. 4 is an explanatory diagram of a pressing process in the embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0022] (Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 2 shows a cross-sectional view of the wound electrode body 1, FIG. 3 shows a perspective view of a battery 100 including the flat wound electrode body 1, and 1 and 2 show side views of a battery module 200 in which a plurality of batteries 100 are stacked and bound together. The battery module 200 is suitable for hybrid cars, plug-in hybrid cars, electric cars, This is a battery module that is installed in vehicles such as cars.
[0023] First, the flat wound electrode body 1 will be described (see FIGS. 1 and 2). The electrode body axial direction AH, the electrode body width direction BH, and the electrode body thickness direction CH of the wound electrode body 1 are shown in FIG. 2. The flat wound electrode body 1 has a flat rectangular parallelepiped shape. The strip-shaped positive electrode plate 10 and the strip-shaped negative electrode plate 20 are placed between a pair of strip-shaped separators (first separator 3 The electrode assembly is wound flatly with a first separator 40 and a second separator 41 sandwiched between them. In the example shown, the first separator 30, the negative electrode plate 20, the second separator 40, and the positive electrode plate 10 are arranged in a flat plate shape. The flat portion 2 is stacked in the electrode body thickness direction CH, and on both sides of this flat portion 2 in the electrode body width direction BH The first separator 30, the negative electrode plate 20, the second separator 40, and the positive electrode plate 10 are positioned respectively. The ribs 3 have a pair of curved portions 3 that are stacked while being bent into a semi-cylindrical shape.
[0024] The positive electrode plate 10 has a positive electrode current collector foil 11 made of a strip of aluminum foil. On both main surfaces of the foil 11, positive electrode active material particles capable of absorbing and releasing lithium ions are disposed. The positive electrode active material layer 12 is formed in a strip shape. is a positive electrode in which the positive electrode active material layer 12 does not exist in the thickness direction and the positive electrode current collector foil 11 is exposed in the thickness direction. The exposed portion 10d of the positive electrode is the exposed portion 10d (see FIG. 2). , and is electrically connected to the positive terminal 120.
[0025] In the flat wound electrode body 1, the positive electrode terminal end 10e at the end of the winding of the positive electrode plate 10 is The flat portion 2 of the electrode body 1 is located at approximately the center of the electrode body width direction BH. In the flat wound electrode body 1 in which the electrode terminal end portion 10e is disposed within the flat portion 2, the floating of the positive electrode terminal end portion 10e The rise in the temperature is suppressed, and the distance between the positive electrode plate 10 and the negative electrode plate 20 is Therefore, in the battery 100 described later, the negative electrode plate 20 Li deposition occurs in the vicinity of the facing portion 20a located radially inside the positive electrode terminal portion 10e and facing the facing portion 20a. This can prevent the following from occurring.
[0026] The negative electrode plate 20 has a negative electrode current collector foil 21 made of a strip-shaped copper foil. On each of the main surfaces, a negative electrode containing negative electrode active material particles capable of absorbing and releasing lithium ions is formed. The active material layer 22 is formed in a strip shape. One end of the negative electrode plate 20 in the width direction has a thickness of The negative electrode exposed portion 2 is a portion in which the negative electrode active material layer 22 is not present in the thickness direction and the negative electrode current collecting foil 21 is exposed in the thickness direction. 0d (see FIG. 2). In the flat wound electrode body 1, the winding end portion of the negative electrode plate 20 is electrically connected to the terminal 130. The negative electrode plate 20 is longer than the positive electrode plate 10 by a predetermined length ΔL1. The winding of the terminal end portion 20e ends after the positive electrode terminal end portion 10e of the positive electrode plate 10.
[0027] The first separator 30 and the second separator 40 are each strip-shaped and made of a porous resin film. The outermost periphery of the flat wound electrode body 1 is formed by the first separator 30. The first separator end 30e at the end of the winding of the separator 30 is secured by adhesive tape (not shown). The first separator 30 is fixed thereto. In the flat wound electrode body 1, the winding ends of the first separator 30 and the second separator 40 The portions are each longer than the negative electrode plate 20 by a predetermined length ΔL2 (longer than the positive electrode plate 10). , the first separator 30 is longer by a predetermined length ΔL3=ΔL1+ΔL2. The first separator end portion 30e and the second separator end portion 40e of the second separator 40 are The winding ends behind the negative electrode terminal end 20e of the negative electrode plate 20. Then, the circumferential position T3 of the first separator end portion 30e and the circumferential position T4 of the second separator end portion 40e are The direction position T4 is the same as the direction position T1, but the first separator 30 is positioned closer to the second separator 40 than the first separator 30. You can also make it longer.
[0028] As a result, the circumferential position T1 of the positive electrode terminal end portion 10e and the outermost position of the flat wound electrode body 1 are and the circumferential position T3 of the first separator terminal end portion 30e are located at a predetermined circumferential positional relationship. Specifically, in this embodiment, the cylindrical wound electrode body 1Z In the figure, the distance from the circumferential position T1 of the positive electrode terminal end portion 10e to the circumferential position T2 of the first separator terminal end portion 30e is The deflection angle θ up to position T3 is approximately θ=+180 degrees (see FIG. 6).
[0029] Next, a battery 100 including the above-described flat wound electrode body 1 will be described (see FIG. 2). In the following description, the battery 100 has a vertical direction DH, a horizontal direction EH, and a thickness direction FH. 2. The battery 100 includes a flat wound electrode body 1 and an internal A flat battery case (hereinafter simply referred to as "case") 110 accommodates the battery in the battery case 11. The case 110 is made up of a positive terminal 120 and a negative terminal 130 supported by the case 110. An electrolyte 140 is contained therein, a part of which is impregnated into the flat wound electrode body 1, The flat wound electrode body 1 is arranged in the vertical direction of the battery. It is covered with a bag-shaped insulating film 150 that is open on one side DH1 of the direction DH.
[0030] The case 110 is a flat rectangular box made of aluminum. The base 110 has a pair of parallel main side surfaces (a first main side surface 111 and a second main side surface 112) and A bottom surface portion 113, a top surface portion 114, and a pair of narrow side surface portions (first narrow side surface portions 11) connect these portions. 5 and second narrow side surface portion 116). 112 are opposed to the flat portions 2 of the flat wound electrode body 1 housed in the case 110. The flat portion 2 is clamped in the thickness direction CH of the electrode body. Since the positive terminal end portion 10e is pressed from the outside, lifting of the positive terminal end portion 10e is effectively prevented. It is under control.
[0031] The case 110 is a rectangular cylindrical case with a bottom and an opening 117c on one side DH1 in the battery longitudinal direction DH. The case body member 117 is welded in a manner that closes the opening 117c of the case body member 117. The case body member 117 is made up of a rectangular plate-shaped case cover member 118 connected to the case body member 117. It houses a flat wound electrode body 1 covered with an edge film 150. On the other hand, the case cover member 118 is provided with a positive terminal 1 made of a plurality of aluminum members. The positive terminal 120 is fixed to the case cover member 118 in an insulated state. , and connected to the positive electrode exposed portion 10d of the positive electrode plate 10 of the flat wound electrode body 1 inside the case 110. While being electrically conductive, it also penetrates the case lid member 118 and extends to the outside of the battery. The negative terminal 130 is made of multiple copper members and is connected to the case cover member 118. The negative terminal 130 is fixed in an insulated state. The negative electrode exposed portion 20d of the negative electrode plate 20 of the electrode assembly 1 is connected to be electrically connected, while the case cover member 1 18 and extends to the outside of the battery.
[0032] Next, a battery module 200 including a plurality of the above-described batteries 100 will be described (see FIG. 3). This battery module 200 is made up of a plurality of batteries 100 stacked in the battery thickness direction FH. and a battery assembly 210 that is constrained from the outside SH1 in the stacking direction SH. The battery assembly 210 includes a plurality of batteries 100 and an insulating A plurality of spacers 215 made of a conductive resin are arranged alternately in the stacking direction SH. The batteries 100 constituting the battery assembly 210 are electrically connected via a bus bar (not shown). It has been done.
[0033] The restraint portion 220 is a pair of end plates 221 made of metal. Four fasteners are provided between the end plates 221 and connect the end plates 221 to each other. The end plate 221 has a bundle band 222. The end plate 221 is aligned in the stacking direction SH of the battery assembly 210. and sandwich the battery assembly 210 in the stacking direction SH. The restraining band 222 is made of a strip-shaped metal plate, and when stretched in the longitudinal direction, both ends are Each of the battery cells is fixed to an end plate 221. Each battery 100 is compressed in the stacking direction SH (battery thickness direction FH). The flat portions 2 of the flat wound electrode body 1 of FIG. 0 are compressed in the thickness direction CH of the electrode body.
[0034] Next, a method for manufacturing the flat wound electrode body 1 and a method for manufacturing the battery 100 using this flat wound electrode body 1 will be described. A method for manufacturing a battery module 200 using the battery 100 will be described (see FIG. 4). ~See Figure 6). First, in the "electrode body manufacturing process" S10 of the "battery manufacturing process" S1, a flat wound electrode body 1 is manufactured. That is, a positive electrode plate 10, a negative electrode plate 20, and a first separator 1 are wound into a roll. 30 and the second separator 40 are prepared, and the "winding step" S11 of the electrode assembly manufacturing step S10 is performed. In this, the first separator 30, the negative electrode plate 20, the second separator 40 and the positive electrode plate 10 are and wound into a cylindrical shape to form a cylindrical wound electrode body 1Z (see FIG. 5).
[0035] The winding device 300 used in this winding step S11 includes a first separator supply unit 311 and a negative electrode Plate supply unit 312, second separator supply unit 313, positive electrode plate supply unit 314, and negative electrode plate cutter a cutting section 321, a positive electrode plate cutting section 322, a separator cutting section 323, a roll section 330, and a winding section and a receiving portion 340. Among these, each supply unit (first separator supply unit 311, negative electrode plate supply unit 312, second separator The separator supply unit 313 and the positive electrode plate supply unit 314 are wound in a roll shape. The separator 30, the negative electrode plate 20, the second separator 40, and the positive electrode plate 10 are rolled in the roll part 330. It is configured to send out the signal toward
[0036] The negative electrode plate cutting section 321 is provided between the negative electrode plate supply section 312 and the roll section 330. The positive electrode plate cutting unit 322 is configured to be able to cut the plate 20. The separator 330 is provided between the roll portion 330 and the positive electrode plate 10, and is configured to be able to cut the positive electrode plate 10. The cutting section 323 is provided between the roll section 330 and the winding section 340. The first separator 30 and the second separator 40 stacked together can be cut at once. There are. The roll section 330 has a pair of pressure rolls 331, and the gap between these rolls The first separator 30, the negative electrode plate 20, the second separator 40, and the positive electrode plate 10 are connected in this order. Continuously overlap. The winding section 340 has a winding roll 341, and winds the first and second sheets of the film stacked in the roll section 330. The first separator 30, the negative electrode plate 20, the second separator 40 and the positive electrode plate 10 are rolled up into a cylindrical shape. It is configured to be able to do so.
[0037] In the winding step S11 using this winding device 300, the separator fed from the first separator supply unit 311 is The first separator 30, the negative electrode plate 20 sent from the negative electrode plate supply unit 312, and the second separator 30 The second separator 40 sent from the separator supply unit 313 and the positive electrode plate The sent positive electrode plates 10 are each directed to the roll section 330. In the roll gap between the pair of pressing rolls 331, the first separator 30, the negative electrode plate 20, the The separator 40 and the positive electrode plate 10 are stacked in this order. The electrode assembly 1Z is then wound cylindrically around a winding roll 341. The first separator end portion 30e is fixed to the cylindrical wound electrode body 1Z by adhesive tape (not shown). do.
[0038] At the end of the winding of the cylindrical wound electrode body 1Z, the positive electrode plate 1 is first cut off by the positive electrode plate cutting portion 322. Next, the negative electrode plate cutting portion 321 is used to cut the negative electrode plate 10 from the positive electrode terminal end portion 10e. The negative electrode plate 20 is cut at a position where the electrode plate 20 is longer by a length ΔL1 (see FIG. 1). The separator cut portion 323 separates the first separator 30 and the negative electrode terminal end portion 20e of the negative electrode plate 20. and the second separator 40 are respectively extended by a length ΔL2 (the positive electrode terminal end portion of the positive electrode plate 10). 10e, the first separator 30 and the second separator 40 have lengths ΔL3=ΔL1 +ΔL2) (see FIG. 1), the first separator 30 and the second separator 4 0 will be disconnected at the same time.
[0039] By cutting in this way, the cylindrical wound electrode body 1Z has a circumferential portion of the positive electrode terminal end portion 10e. The position T1 and the circumferential position T3 of the first separator end portion 30e are located in a predetermined circumferential positional relationship. In this embodiment, as shown in FIG. 6, the positive electrode terminal end portion 10e can be The deflection angle θ from the position T1 to the circumferential position T3 of the first separator terminal end portion 30e is set to θ=+18 0 degrees. The first separator 30 and the second separator 40 are cut at the separator cutting portion. By simultaneously cutting at 323, the circumferential position T3 of the first separator terminal end portion 30e and the The circumferential position T4 of the second separator end portion 40e is the same position.
[0040] Next, in the "pressing step" S12 of the electrode body manufacturing step S10, a press device 400 is used. Then, the cylindrical wound electrode body 1Z is pressed and crushed to form a flat wound electrode body 1 (see FIG. 6). In this pressing step S12, the positive electrode terminal end portion 10e of the positive electrode plate 10 is pressed against the flat wound electrode body 1. The pressing is performed so that the flat portion 2 is positioned within the flat portion 2. First, the cylindrical wound electrode body 1Z is placed on the lower die 420. At that time, the first separator 30 The circumferential position T3 of the separator end portion 30e is set to a predetermined circumferential position TA (in this embodiment The cylindrical wound electrode body 1Z is placed on the lower die 420 in such a position that the upper part is directly above the lower die 420.
[0041] Here, in the cylindrically wound electrode body 1Z, the positive electrode terminal end 10e of the positive electrode plate 10 is It is hidden inside the electrode body 1Z and cannot be seen from the outside in the radial direction of the cylindrical wound electrode body 1Z. Therefore, the circumferential position T1 of the positive electrode terminal end portion 10e can be identified from the appearance of the cylindrical wound electrode body 1Z. It is difficult to do so. In contrast, in the winding step S11, the circumferential position T1 of the positive electrode terminal end portion 10e and the first The separator end portion 30e has a predetermined circumferential positional relationship with the circumferential position T3. The first separator terminal end portion 30e is located at the outermost periphery of the cylindrical wound electrode body 1Z, and therefore, Therefore, in the pressing step S12, the pressing device 400 The cylindrical wound electrode body 1Z is arranged such that the circumferential position T3 of the first separator terminal end portion 30e is By arranging the positive electrode terminal end 10e in a position where the circumferential position T1 is It can be arranged at a predetermined circumferential position TB.
[0042] In this embodiment, in the winding step S11, the positive electrode terminal end portion 10e is wound from the circumferential position T1 to the The deflection angle θ from the separator end portion 30e to the circumferential position T3 is set to +180 degrees. Thus, the circumferential position T3 of the first separator end portion 30e is the circumferential position TA (directly above). The cylindrical wound electrode body 1Z is placed on the lower die 420 in this position, so that the circumference of the positive electrode terminal end portion 10e is The circumferential position T1 can be located at the circumferential position TB (directly below in this embodiment). Thereafter, the cylindrical wound electrode body 1Z is pressed between the upper die 410 and the lower die 420 of the press device 400. The electrode assembly 1 is then flattened to form a flat wound electrode body 1. As a result, the positive electrode terminal end portion 10e is The flat portion 2 of the flat wound electrode body 1 is disposed at approximately the center in the electrode body width direction BH. The positive electrode terminal end 10e is disposed within the flat portion 2, and the positive electrode terminal end 10e is prevented from floating up. Thus, a flat wound electrode body 1 is manufactured.
[0043] Next, in the "battery assembly process" S20 of the battery manufacturing process S1, the above-mentioned flat wound electrode body 1 is used to assemble the battery 100. First, in the "terminal connection step" S21 of the battery assembly step S20, the case lid member 118 A positive terminal 120 and a negative terminal 130 are fixed to the The electrode terminal 130 is connected to the exposed positive electrode portion 10d of the positive electrode plate 10 and the exposed negative electrode plate 20 of the flat wound electrode body 1. The positive electrode terminal 120 and the negative electrode terminal 130 are welded to the negative electrode exposed portion 20d of the It is electrically connected to the electrode body 1.
[0044] Next, in the "accommodating step" S22, the flat wound electrode body 1 is placed in a bag-shaped insulating film 15. 0, and insert them into the case body member 117. The opening 117c is closed with the case cover member 118. Then, the case body member 117 and the case cover are The case 110 is formed by welding the case cover member 118 to the case cover member 118 all around. The flat portion 2 of the flat wound electrode body 1 housed in the case 110 is The electrode body is sandwiched between the side surface portion 111 and the second main side surface portion 112 in the thickness direction BH. This more effectively prevents the positive electrode terminal end portion 10e of the positive electrode plate 10 from floating up. Next, in a "pouring step" S23, the electrolyte 140 is poured into the pouring hole (not shown) of the case lid member 118. The liquid is poured into the case 110 through a liquid pouring hole (shown), and the liquid pouring hole is sealed with a sealing member (not shown). performs initial charging, aging, various inspections, etc. on this battery 100. 100 will be produced.
[0045] Next, in the "module assembly process" S2, a plurality of batteries 100 are stacked in the battery thickness direction FH. The battery 100 is then flatly wound and restrained from the outer side SH1 in the stacking direction SH by the restraining portion 220. The flat portions 2 of the electrode bodies 1 are compressed in the thickness direction FH of the electrode bodies to form a battery module 200. Specifically, the batteries 100 and the spacers 215 are stacked alternately in the battery thickness direction FH. The battery assembly 210 is formed by stacking the battery cells 210 in the stacking direction SH. , and the end plates 221 of the restraint portion 220 are placed on top of each other. 210 and the end plate 221 from the outside SH1 in the stacking direction SH. While pressing, the restraining bands 222 of the restraining portion 220 are respectively hung on the end plates 221. Then, the batteries 100 are connected to each other using a bus bar (not shown). In this way, the battery module 200 is completed.
[0046] As described above, in the method for manufacturing the flat wound electrode body 1, the positive electrode plate 10 is pressed. The cylindrical wound electrode body 1Z is arranged so that the pole end portion 10e is located within the flat portion 2 of the flat wound electrode body 1. The flat wound electrode body 1 is then pressed to form the flat wound electrode body 1. In the electrode body 1, the positive electrode terminal portion 10e of the positive electrode plate 10 is disposed within the flat portion 2 of the flat wound electrode body 1. Therefore, in any of the flat wound electrode bodies 1, the lifting of the positive electrode terminal end portion 10e can be prevented. The distance between the positive electrode plate 10 and the negative electrode plate 20 becomes uneven near the positive electrode terminal end portion 10e. This can suppress the
[0047] Furthermore, in this embodiment, first, in the winding step S11, the positive electrode terminal end portion 10e of the positive electrode plate 10 is wound. The circumferential position T1 and the circumferential position T3 of the first separator terminal end portion 30e of the first separator 30 The cylindrical wound electrode body 1Z is formed so that the electrodes 11 and 12 have a predetermined circumferential positional relationship. In the pressing step S12, the cylindrical wound electrode body 1Z is pressed against the circumferential surface of the first separator terminal end portion 30e. The electrode is then placed in a position such that the circumferential position T3 is at a predetermined circumferential position TA, and pressed. The end portion 10e is disposed within the flat portion 2 of the flat wound electrode body 1. The first separator terminal end portion 30e is , which are present on the outermost periphery of the cylindrical wound electrode body 1Z and can be easily seen from the outside in the radial direction. Therefore, by using the circumferential position T3 of the first separator terminal end portion 30e as a reference, The positive electrode terminal end portion 10e can be reliably arranged within the flat portion 2 of the flat wound electrode body 1.
[0048] In the manufacturing method of the battery 100, the flat wound electrode body 1 manufactured in the electrode body manufacturing step S10 is Therefore, in any battery 100 manufactured, Even if the positive electrode terminal end portion 10e is lifted, the positive electrode plate 10 and the negative electrode plate 10 are prevented from lifting up. Therefore, it is possible to prevent the distance between the electrodes 20 from becoming uneven. In addition, the vicinity of the portion of the negative electrode plate 20 that is located radially inside and facing the positive electrode terminal end portion 10e This can suppress the occurrence of Li deposition.
[0049] In addition, in the battery 100 manufactured in the battery manufacturing process S1, the flat portion 2 of the flat wound electrode body 1 is The positive electrode plate 10 is sandwiched between a pair of main side surfaces 111 and 112 of the base 110. The positive electrode terminal 10e is pressed from the outside, so the positive electrode terminal 10e is lifted up more effectively. Since this effectively suppresses Li deposition caused by the lifting of the positive electrode terminal portion 10e, can be effectively suppressed.
[0050] In the manufacturing method of the battery module 200, the battery 100 manufactured in the battery manufacturing process S1 is The battery module 200 is manufactured using the same. In all the batteries 100 included in this study, the L caused by the lifting of the positive electrode terminal portion 10e Furthermore, in this battery module 200, each battery 100 is restrained. The flat portions 2 of the flat wound electrode body 1 are compressed in the thickness direction CH of the electrode body. Therefore, the positive terminal end 10e is pressed from the outside, and the positive terminal end 10e is not lifted. Since this can be more effectively suppressed, Li deposition due to the lifting of the positive electrode terminal portion 10e can be prevented. can be further suppressed.
[0051] Although the present invention has been described above based on the embodiments, the present invention is not limited to the embodiments. It goes without saying that the present invention can be modified and applied as appropriate within the scope of its essence. do not have. [Explanation of symbols]
[0052] 1 Flat wound electrode body 1Z Cylindrical wound electrode body 2 Flat area 3 R section 10 Positive electrode plate 10e Positive terminal end 20 negative electrode plate 20e Negative terminal end 30 First separator 30e First separator end 40 Second separator 40e Second separator end 100 batteries 110 Flat battery case (case) 111 1st main side part 112 2nd main side part 200 battery modules 210 Battery assembly 220 Restraint part 300 Winding device 400 Press Equipment CH Electrode body thickness direction FH Battery thickness direction SH stacking direction SH1 (stack direction) outside T1 Circumferential position (of positive electrode end) T3 Circumferential position (of the first separator end) TA,TB (predetermined) circumferential position θ declination S1 Battery manufacturing process S10 Electrode manufacturing process S11 Winding process S12 Pressing process S20 Battery Assembly Process S21 Terminal connection process S22 Storage process S23 Liquid injection process S2 module assembly process
Claims
1. A flat wound electrode body in which a band-shaped positive electrode plate and a band-shaped negative electrode plate are wound flatly with a pair of band-shaped separators interposed therebetween, the flat wound electrode body having a flat portion and a pair of R portions located on both sides of the flat portion, Of the pair of separators, the first separator that is wound last is wound a predetermined length longer than the positive electrode end portion of the positive electrode plate. Flat wound electrode body.
2. The flat wound electrode body according to claim 1, The positive electrode terminal portion of the positive electrode plate is located within the flat portion. Flat wound electrode body.
3. The flat wound electrode body according to claim 2, the predetermined length is a length at which a first separator end portion at a winding end of the first separator is positioned within the flat portion when the positive electrode end portion of the positive electrode plate is positioned within the flat portion, The positive electrode terminal portion of the positive electrode plate is located within the flat portion, The first separator end portion of the first separator is located within the flat portion. Flat wound electrode body.
4. The flat wound electrode body according to claim 3, the predetermined length is a length at which, when the positive electrode terminal end portion of the positive electrode plate is positioned at the center of the flat portion, the first separator terminal end portion of the first separator is positioned at the center of the flat portion on the opposite side in the thickness direction of the electrode body, The positive electrode terminal end portion is located at the center of the flat portion in the width direction of the electrode body, The first separator end portion is located on the opposite side of the flat portion in the thickness direction of the electrode assembly and in the center in the width direction of the electrode assembly. Flat wound electrode body.
5. A flat wound electrode body according to any one of claims 1 to 4, a battery case having a pair of main side surfaces facing the flat portion of the flat wound electrode body, the battery case housing the flat wound electrode body in a state in which the flat portion is sandwiched between the pair of main side surfaces. battery.
6. A plurality of the batteries according to claim 5 are stacked in a battery thickness direction connecting a pair of the main side surface portions, The flat portions of the flat wound electrode bodies of the respective batteries are compressed in the thickness direction of the electrode bodies by being restrained from the outside in the stacking direction by the restraining portions. Battery module.
7. A method for producing a flat wound electrode body according to any one of claims 1 to 4, The last separator of the pair of separators that has been completely wound is wound by the predetermined length based on the positive electrode end portion of the positive electrode plate. A method for manufacturing a flat wound electrode body.
8. A method for producing the battery according to claim 5, comprising the steps of: The method includes a step of accommodating the flat wound electrode body in the battery case with the flat portion sandwiched between the pair of main side surface portions. How batteries are manufactured.