Flat wound electrode body, battery, battery module, and method for manufacturing the flat wound electrode body and battery.

Abstract

To provide a manufacturing method of a flat wound electrode body, etc., which suppresses nonuniformity in inter-electrode plate distance between a positive electrode plate and a negative electrode plate in the vicinity of a positive electrode termination part by suppressing floating of the positive electrode termination part.SOLUTION: A manufacturing method of a flat wound electrode body 1 in which a strip positive electrode plate 10 and a strip negative electrode plate 20 are flatly wound via a pair of strip separators 30 and 40, includes: a winding step S11 of forming a cylindrical wound electrode body 1Z by cylindrically winding the positive electrode plate 10 and the negative electrode plate 20 via the pair of separators 30 and 40; and a press step S12 of forming the flat wound electrode body 1 by pressing and crushing the cylindrical wound electrode body 1Z. In the press step S12, the pressing is performed in such a manner that a positive electrode termination part 10e, which is a winding end of the positive electrode plate 10, is positioned within a flat part 2 of the flat wound electrode body 1.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a battery module including a battery provided with a flat wound electrode in which a strip-shaped positive electrode plate, a negative electrode plate, and a pair of separators are wound flatly. body, This battery provided with this flat wound electrode body Pond, relates to a manufacturing method thereof. , and flat wound electrode body and battery

Background Art

[0002] Conventionally, as an electrode body of a battery, a flat wound electrode body in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are wound flatly via a pair of strip-shaped separators is known. This flat wound electrode body is manufactured as follows. That is, a strip-shaped positive electrode plate, a strip-shaped separator, a strip-shaped negative electrode plate, and a strip-shaped separator are stacked in this order and wound cylindrically to form a cylindrical wound electrode body. Next, this cylindrical wound electrode body is pressed and crushed into a flat shape to form a flat wound electrode body. Note that the wound electrode body is usually formed such that the negative electrode plate is longer than the positive electrode plate, and the separator is longer than these, and after the positive electrode plate finishes winding, the negative electrode plate finishes winding, and then the separator finishes winding. Note that, as a related prior art, for example, Patent Document 1 can be cited (see FIGS. 1 and 2 of Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when pressing the cylindrical wound electrode body, each component that makes up the cylindrical wound electrode body (positive electrode plate) , the circumferential position of the winding end portion of the negative electrode plate and the pair of separators, particularly the negative electrode plate and the separator Regarding the circumferential position of the positive electrode terminal of the positive electrode plate, which is hidden inside by the inverter, This was not considered. Therefore, when setting the cylindrical wound electrode body in the press machine, the circumferential direction Depending on the arrangement, the circumferential position of the positive electrode terminal in the resulting flat wound electrode body may vary. It was fluctuating. That is, the positive electrode terminal was the flat portion of the flat wound electrode body (positive electrode plate, negative electrode plate and When a flat wound electrode body is manufactured located within the area where the separators are stacked in a flat plate shape. In addition, there are R-shaped parts (positive electrode plate, negative electrode plate) located on both sides of the flat portion of the flat wound electrode body. (and the flat wound electrode body located within the area where the separators are stacked while bending in a semi-cylindrical shape) In some cases, they were manufactured.

[0005] However, the positive electrode terminal is less prone to bending than the middle portion of the positive electrode plate in the longitudinal direction. If the positive electrode terminal is located within the R portion of the flattened wound electrode body, the positive electrode terminal will float up. This refers to the positive electrode terminal and the opposing portion of the negative electrode plate located radially inward from the positive electrode terminal. The distance between the positive and negative electrodes tends to increase, and the inter-plate distance between the positive and negative electrodes near the positive electrode termination becomes uneven. It has become clear that it is easy to get the number one.

[0006] This invention was made in view of the current situation. , flat flat wound electrode body, This electric device equipped with a flattened wound electrode body pond, Furthermore, a battery module in which multiple batteries containing this flattened wound electrode body are stacked and constrained. , and flat wound electrode body and battery A method for manufacturing this product is provided. [Means for solving the problem]

[0007] One aspect of the present invention for solving the above problems is (1) a flat wound electrode body in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are wound in a flat shape via a pair of strip-shaped separators, and having a flat portion and a pair of R portions located on both sides of the flat portion, wherein the first separator, which is the last to be wound, is the positive electrode end portion of the positive electrode plate at the end of the winding Rather Long and coiled Furthermore, the length of the long winding of the first separator with respect to the positive electrode end portion is such that, when the positive electrode end portion of the positive electrode plate is positioned in the center of the flat portion, the first separator end portion of the first separator is located in the center of the flat portion on the opposite side in the electrode thickness direction, the positive electrode end portion is located in the center of the flat portion in the electrode width direction, and the first separator end portion is located in the center of the flat portion in the electrode width direction on the opposite side in the electrode thickness direction. That is the case. ( 2 ) Alternatively, the battery may include a flat wound electrode body as described in (1), and a battery case having a pair of main side surfaces facing the flat portion of the flat wound electrode body, the flat wound electrode body being housed in a state where the flat portion is sandwiched between the pair of main side surfaces. ( 3 ) Furthermore, multiple ( 2 The batteries described in the above are stacked in the battery thickness direction connecting a pair of main side portions, and are restrained from the outside in the stacking direction by a restraining portion, so that the flat portion of the flat wound electrode body of each battery is compressed in the electrode body thickness direction. ( 4 )Furthermore, a method for manufacturing a flat wound electrode body as described in (1), wherein, of the pair of separators, the last separator to be wound is used as a reference to the positive electrode end portion of the positive electrode plate at the end of the winding, When the positive electrode end portion of the positive electrode plate is positioned in the center of the flat portion, the length of the first separator end portion of the first separator is such that it is located in the center of the flat portion on the opposite side in the electrode thickness direction. A manufacturing method for flat, wound electrode bodies that are wound only a long length is preferable. ( 5 ) or ( 2 A method for manufacturing a battery as described in () is preferable, which includes a housing step of housing the flat wound electrode body in a battery case in a state in which the flat portion is sandwiched between the pair of main side portions. Still other aspects are a method for manufacturing a flat wound electrode body in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are flatly wound via a pair of strip-shaped separators, the method including a winding step of winding the positive electrode plate and the negative electrode plate via the pair of separators in a cylindrical shape to form a cylindrical wound electrode body, and a pressing step of pressing and crushing the cylindrical wound electrode body to form the flat wound electrode body, wherein the pressing step is a method for manufacturing a flat wound electrode body that performs pressing such that the positive electrode end portion at the end of winding of the positive electrode plate is positioned within the flat portion of the flat wound electrode body.

[0008] In the method for manufacturing the flat wound electrode body described above, the cylindrical wound electrode body is pressed so that after pressing, the positive electrode end portion of the positive electrode plate is positioned within the flat portion of the flat wound electrode body, thereby forming the flat wound electrode body. As a result, in any flat wound electrode body to be manufactured, the positive electrode end portion of the positive electrode plate can be arranged within the flat portion of the flat wound electrode body. Therefore, in any flat wound electrode body, the lifting of the positive electrode end portion can be suppressed, and the unevenness of the electrode plate distance between the positive electrode plate and the negative electrode plate near the positive electrode end portion can be suppressed. 。これにより、製造されるいずれの扁平捲回電極体においても、正極板の正極終端部を扁 平捲回電極体の平坦部内に配置できるので、いずれの扁平捲回電極体においても、正極終 端部の浮き上がりを抑制し、正極終端部付近で正極板と負極板との極板間距離が不均一に なるのを抑制できる。

[0009] Furthermore, in the method for manufacturing the flat wound electrode body described above, in the winding step, the cylindrical wound electrode body is formed such that the circumferential position of the positive electrode end portion and the circumferential position of the first separator end portion of the first separator that is wound last among the pair of separators have a predetermined circumferential position relationship, and in the pressing step, the cylindrical wound electrode body is arranged in a posture in which the circumferential position of the first separator end portion is a predetermined circumferential position, and then the pressing is performed. 方向位置と、前記一対のセパレータのうち、最後に巻き終わる第1セパレータの第1セパ レータ終端部の周方向位置とが、予め定めた周方向位置関係となるように、前記円筒捲回 電極体を形成し、前記プレス工程は、上記円筒捲回電極体を、上記第1セパレータ終端部 の上記周方向位置が予め定めた周方向位置となる姿勢に配置して、前記プレスを行う扁平 捲回電極体の製造方法とすると良い。

[0010] In a wound electrode body, usually, the entire negative electrode plate is made longer than the positive electrode plate so that the entire positive electrode plate faces the negative electrode plate via a separator. Also, to ensure insulation between the positive electrode plate and the negative electrode plate, うに、正極板よりも負極板を長くしている。また正極板と負極板との間を確実に絶縁する Therefore, the pair of separators are made even longer than the negative electrode plate. For this reason, the cylindrical wound electrode In this body, the positive electrode end of the positive electrode plate is hidden inside the cylindrical wound electrode body, and the cylindrical wound electrode In many cases, the polar body cannot be seen from the radially outer side. Therefore, in the pressing process, cylindrical winding It is often difficult to determine the circumferential position of the positive electrode terminal from the external appearance of the electrode body.

[0011] In contrast, in the above-mentioned manufacturing method, first in the winding process, the circumferential direction of the positive electrode end portion of the positive electrode plate The position and the circumferential position of the end portion of the first separator that finishes winding are predetermined. A cylindrical wound electrode body is formed so that it has a predetermined circumferential positional relationship. For example, positive electrode termination The angle of deviation from the part to the end of the first separator is set to +180 degrees, or +150 to +210 degrees. Examples include setting it within a certain range. Then, in the pressing process, the circumferential position of the end of the first separator is a predetermined circumferential position The cylindrical wound electrode body is positioned in the desired orientation, pressed, and the positive electrode end is flattened into a wound electrode. It is placed within the flat portion of the body. The first separator terminal is located at the outermost circumference of the cylindrical wound electrode body. Therefore, it can be easily seen from the radially outer side. Thus, the circumferential position of the end portion of the first separator is By using this as a reference, the positive electrode terminal can be easily and reliably positioned within the flat portion of the flattened wound electrode body. .

[0012] In another embodiment, a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are separated by a pair of strip-shaped separators. A method for manufacturing a battery comprising a flat wound electrode body, wherein the flat wound electrode body described above An electrode manufacturing process for manufacturing the flat wound electrode body using the electrode body manufacturing method, and the flat wound A method for manufacturing a battery, comprising a battery assembly step of assembling the battery using electrode bodies. .

[0013] The inventors' investigation revealed that the positive electrode terminal portion of the positive electrode plate is positioned within the R portion of the flattened wound electrode body. In batteries, as they are used, the negative electrode plate near the positive terminal, specifically the negative electrode plate, Located radially inward at the electrode end, near the opposing opposing portion, the battery reaction occurs as it moves between the electrode plates. The metal ions that carry the load are reduced to the metal (for example, Li in lithium-ion secondary batteries) It has become clear that it is easy to extract. The reason is, as mentioned above, when the positive electrode terminal is located within the R portion of the flattened wound electrode body. In this case, the positive electrode terminal is lifted up, and the distance between the positive electrode terminal and the aforementioned opposing portion of the negative electrode plate is large. This tends to happen. As a result, the resistance in this area becomes locally high, and the negative electrode potential becomes locally low. This can result in a negative deposition potential, which 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, the battery manufacturing method described above uses flat windings produced by the aforementioned manufacturing method. The battery is assembled using electrode bodies. Therefore, in any battery that is manufactured, This suppresses the lifting of the electrode terminals and prevents unevenness in the distance between the positive and negative electrodes near the positive electrode terminal. It is possible to suppress the state from becoming 1. Therefore, in any battery, the positive terminal of the negative electrode plate Metal precipitation, such as Li precipitation, occurs near opposing parts located radially inward of the part. This can suppress it.

[0015] Furthermore, the "battery" refers to a battery in which the aforementioned flat wound electrode body is housed in a metal battery case. Ponds, and batteries in which flattened wound electrode bodies are housed in a battery case made of laminate film, etc. In addition, in a battery, the flat portion of the flat wound electrode body and the battery case are directly or They may be in close contact via an insulating film or the like, or the flat portion of the flat wound electrode body and the battery case There may be a gap between them.

[0016] Furthermore, the above-mentioned method for manufacturing a battery, wherein the battery is the flattened winding Return power The pole body has a pair of main side surfaces facing each other on the flat portion, and the flat portion is sandwiched between the pair of main side surfaces, Return power It is equipped with a flat battery case that houses the polar body, and the battery assembly process is the flat winding Return power The battery manufacturing method should include a housing step of housing the electrode body inside the flat battery case described above.

[0017] The batteries manufactured using the above-described method have a flat portion of the flat wound electrode body that forms a pair of flat battery cases. It is being pressed between the main side surfaces. Therefore, the positive terminal of the positive electrode plate is being pressed from the outside. Therefore, the lifting of the positive electrode terminal is more effectively suppressed, so the lifting of the positive electrode terminal is This further suppresses the aforementioned metal deposition caused by the aforementioned factors.

[0018] In another embodiment, a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are separated by a pair of strip-shaped separators. Multiple batteries, each having a flattened wound electrode body, are stacked in the thickness direction of the battery and are restrained. The flat portion of the flat wound electrode body of each battery is constrained from the outside in the stacking direction by the part, and each A method for manufacturing a battery module in which the electrode body is compressed in the thickness direction, and the manufacturing of the aforementioned battery The method comprises a battery manufacturing process for producing the above-mentioned battery, and a process for transporting multiple of the above-mentioned batteries in the direction of the battery thickness. The flat wound electrodes of each battery are stacked and restrained from the outside in the stacking direction by the restraining portion. The above-mentioned flat parts of the body are compressed in the direction of the electrode body thickness to assemble the battery module. This is a method for manufacturing a battery module, comprising a module assembly process.

[0019] The above-described method for manufacturing the battery module uses a battery manufactured by the aforementioned manufacturing method. And, the battery module is manufactured. Therefore, this battery module contains In all batteries, metal deposition caused by lifting of the positive electrode terminal of the positive electrode plate has been suppressed. Moreover, in this battery module, each battery is constrained, and the flat portion of the flat wound electrode body is each The electrode body is compressed in the thickness direction. Therefore, the positive electrode terminal is pressed from the outside. Therefore, the lifting of the positive terminal is more effectively suppressed. This further suppresses metal deposition caused by [the aforementioned factor].

[0020] Furthermore, as for the "battery module," for example, multiple batteries are directly stacked and constrained by a restraining part. Battery modules, or multiple batteries stacked alternately with spacers in between and restrained in a restraining section. Examples include battery modules. [Brief explanation of the drawing]

[0021] [Figure 1] This is a simplified cross-sectional view of a flat wound electrode body according to an embodiment, perpendicular to the electrode body axis direction. [Figure 2] This is a perspective view of the battery according to the embodiment. [Figure 3] This is a side view of a battery module according to an embodiment. [Figure 4] This is a flowchart illustrating the manufacturing process of a battery module, including the manufacturing of a flat wound electrode body and the manufacturing of a battery, according to an embodiment. [Figure 5] This is an explanatory diagram of the winding process according to an embodiment. [Figure 6] This is an explanatory diagram of the press process relating to an embodiment. [Modes for carrying out the invention]

[0022] (Embodiment) Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figure 1 shows a flat according to this embodiment. Figure 2 shows a cross-sectional view of the wound electrode body 1, Figure 3 shows a perspective view of a battery 100 equipped with the flat wound electrode body 1, and Figure 3 shows a perspective view of the wound electrode body 1. The images show side views of a battery module 200 in which multiple batteries 100 are stacked and constrained. The battery module 200 is for hybrid cars, plug-in hybrid cars, and electric vehicles. This is a battery module installed in vehicles such as cars.

[0023] First, we will explain the flat wound electrode body 1 (see Figures 1 and 2). In the following, we will refer to it as flat The axial direction AH, width direction BH, and thickness direction CH of the wound electrode body 1 are shown in Figure 1. And the directions shown in Figure 2 will be defined and explained. This flat wound electrode body 1 is a flat rectangular parallelepiped shape. A strip-shaped positive electrode plate 10 and a strip-shaped negative electrode plate 20 are connected to a pair of strip-shaped separators (first separator 3) This is an electrode body wound in a flattened shape via a second separator (40). Flattened wound electrode body 1 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. Flat portions 2 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 located in the respective positions. It has a pair of R-shaped sections 3 that are stacked on top of each other 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 are positive electrode active material particles capable of intercalating and releasing lithium ions. A positive electrode active material layer 12 containing is formed in a strip shape. One end of the positive electrode plate 10 in the width direction In this case, the positive electrode active material layer 12 is absent in the thickness direction, and the positive electrode current collector foil 11 is exposed in the thickness direction. This is the exposed portion 10d (see Figure 2). This positive electrode exposed portion 10d is in the battery 100. It is electrically connected to the positive terminal 120.

[0025] In the flat wound electrode body 1, the positive electrode end portion 10e at the end of the winding of the positive electrode plate 10 is flat wound It is located approximately in the center of the electrode width BH of the flat portion 2 of the electrode body 1. In a flat wound electrode body 1 where the electrode terminal portion 10e is located within the flat portion 2, the floating of the positive electrode terminal portion 10e The upward movement is suppressed, and the distance between the positive electrode plate 10 and the negative electrode plate 20 near the positive electrode termination 10e is The unevenness is suppressed. Therefore, in the battery 100 described later, the negative electrode plate 20 Li deposition occurs near the opposing portion 20a, which is located radially inward of the positive electrode terminal portion 10e. This can suppress the occurrence of [the problem].

[0026] The negative electrode plate 20 has a negative electrode current collector foil 21 made of a strip of copper foil. Each of the main surfaces contains negative electrode active material particles capable of intercepting and releasing lithium ions. The active material layer 22 is formed in a strip shape. Of the negative electrode plate 20, one end in the width direction has a thickness In the negative electrode exposed portion 2, the negative electrode active material layer 22 is absent in that direction, and the negative electrode current collector foil 21 is exposed in the thickness direction. It is 0d (see Figure 2). This exposed negative electrode portion 20d is the negative terminal of the battery 100. It is electrically connected to the child 130. In the flat wound electrode body 1, the end of the winding of the negative electrode plate 20 The negative electrode of the negative electrode plate 20 is made longer than the positive electrode plate 10 by a predetermined length ΔL1, and the negative electrode of the negative electrode plate 20 The termination portion 20e is wound after the positive terminal portion 10e of the positive electrode plate 10.

[0027] The first separator 30 and the second separator 40 are each made from a porous membrane made of resin in the shape of a strip. The outermost periphery of the flattened wound electrode body 1 is formed by the first separator 30, and the first separator The first separator end portion 30e at the end of winding of the separator 30 is attached with an adhesive tape (not shown). It is fixed to the first separator 30. In the flat wound electrode body 1, the end of the winding of the first separator 30 and the second separator 40 Each portion is longer than the negative electrode plate 20 by a predetermined length ΔL2 (longer than the positive electrode plate 10). (and is made longer by a predetermined length ΔL3 = ΔL1 + ΔL2), and the first separator 30 The first separator terminal 30e and the second separator terminal 40e of the second separator 40 are Each winding is completed after the negative electrode end portion 20e of the negative electrode plate 20. Now, the circumferential position T3 of the first separator end portion 30e and the circumferential position of the second separator end portion 40e The directional position T4 is the same position, but the first separator 30 is positioned further than the second separator 40. You can also make it longer by wrapping it around your neck.

[0028] As a result, the circumferential position T1 of the positive electrode terminal portion 10e and the circumferential position T3 of the first separator terminal portion 30e located on the outermost periphery of the flat wound electrode body 1 are predetermined. Ta-shu This represents a directional positional relationship. Specifically, in this embodiment, in the cylindrical wound electrode body 1Z before pressing, which will be described later, the angle θ from the circumferential position T1 of the positive electrode end portion 10e to the circumferential position T3 of the first separator end portion 30e is approximately θ = +180 degrees (see Figure 6).

[0029] Next, the battery 100 equipped with the flat wound electrode body 1 described above will be explained (see Figure 2). In the following, the battery's longitudinal direction DH, battery's transverse direction EH, and battery's thickness direction FH will be shown in Figure 2. toThe following explanation will be given in the direction indicated. This battery 100 consists of a flat wound electrode body 1, a flat battery case (hereinafter also simply referred to as "case") 110 that houses it, and positive electrode terminals 120 and negative electrode terminals 130, etc., supported by the case 110. An electrolyte 140 is contained inside the case 110, a portion of which is impregnated into the flat wound electrode body 1, and a portion which accumulates on the bottom surface 113 of the case 110. The flat wound electrode body 1 is covered with a bag-shaped insulating film 150 that opens on one side DH1 in the vertical direction DH of the battery.

[0030] Of these, case 110 is a flat, rectangular box made of aluminum. S110 has a pair of parallel main side portions (first main side portion 111 and second main side portion 112), Connecting these are the bottom portion 113, the top portion 114, and a pair of narrow side portions (first narrow side portion 11 It has 5 and a second narrow side portion 116). Of these, the first main side portion 111 and the second main side portion 112 is opposite to the flat portion 2 of the flat wound electrode body 1 housed in the case 110. The flat portion 2 is then compressed in the electrode body thickness direction CH. This compresses the positive electrode end of the positive electrode plate 10. Since part 10e is held down from the outside, the lifting of the positive electrode terminal part 10e is effectively suppressed. It's under control.

[0031] Case 110 is a bottomed rectangular tubular shape with an opening 117c on one side DH1 in the vertical direction DH of the battery. The case body member 117 and the opening 117c of the case body member 117 are sealed in a manner that closes the opening 117c of the case body member 117. It consists of a rectangular plate-shaped case lid member 118 that is in contact with it. The case body member 117 is an insulating It houses a flat, wound electrode body 1 covered with an edge film 150. On the other hand, the case lid member 118 has a positive terminal 1 made of multiple aluminum members. 20 is fixed in place in an insulated state from the case lid member 118. This positive terminal 120 is Inside the case 110, the flattened wound electrode body 1 is connected to the positive electrode exposed portion 10d of the positive electrode plate 10. While conducting electricity, it extends through the case cover member 118 to the outside of the battery. Material 118 has a negative electrode terminal 130 made of multiple copper components, and the case lid member 118 and It is fixed in an insulated state. This negative terminal 130 is flattened inside the case 110. One of the rotating electrode body 1 is connected to the negative electrode exposed portion 20d of the negative electrode plate 20 and is electrically connected, while the case lid member 1 It penetrates through 18 and extends to the outside of the battery.

[0032] Next, a battery module 200 comprising multiple of the above-mentioned batteries 100 will be described (Figure 3). (See reference). This battery module 200 consists of multiple batteries 100 stacked in the battery thickness direction FH. A battery assembly 210 including and restraining this battery assembly 210 from the outside SH1 in the stacking direction SH. It includes a restraining part 220. The battery assembly 210 includes a plurality of batteries 100 and an insulating Multiple spacers 215 made of resin are arranged alternately in the lamination direction SH. Each battery 100 constituting the battery assembly 210 is electrically connected via a busbar (not shown). It is being done.

[0033] The restraining part 220 consists of a pair of end plates 221 made of metal and these end plates Four connecting rods are stretched between the two end plates 221, connecting them to one another. It has a bundle band 222. The end plate 221 is in the stacking direction SH of the battery assembly 210. They are positioned on the outer SH1 and sandwich the battery assembly 210 in the stacking direction SH. The restraint band 222 is made of a strip of metal plate and, when stretched in the longitudinal direction, both ends are Each is fixed to the end plate 221. This constitutes the battery assembly 210. Each battery 100 is compressed in the stacking direction SH (battery thickness direction FH), and each battery 10 The flat portions 2 of the flat wound electrode body 1 of type 0 are each compressed in the electrode body thickness direction CH.

[0034] Next, a method for manufacturing the flattened wound electrode body 1, and a method for manufacturing a battery 100 using this flattened wound electrode body 1. The method and the manufacturing method of the battery module 200 using the battery 100 will be described (Figure 4). (See Figure 6). First, in the "electrode body manufacturing process" S10 of the "battery manufacturing process", flat wound electrode body 1 is manufactured. That is, a positive electrode plate 10, a negative electrode plate 20, and a first separator, each wound in a roll shape. Prepare 30 and the second separator 40, and in the electrode body manufacturing process S10, the "winding process" S11 In this configuration, the first separator 30, the negative electrode plate 20, the second separator 40, and the positive electrode plate 10 are arranged in this configuration. The materials are stacked in this order and wound into a cylindrical shape to form a cylindrical wound electrode body 1Z (see Figure 5).

[0035] The winding device 300 used in this winding process S11 includes a first separator supply unit 311 and a negative electrode The plate supply unit 312, the second separator supply unit 313, the positive electrode plate supply unit 314, and the negative electrode plate cutting unit. Section 321, positive electrode plate cutting section 322, separator cutting section 323, roll section 330, winding It is equipped with a take-up section 340. Of these, each supply unit (first separator supply unit 311, negative electrode plate supply unit 312, second separator The supply unit 313 and the positive electrode plate supply unit 314) each member (first separator) wound in a roll shape The terminals (30, negative electrode plate 20, second separator 40, and positive electrode plate 10) are each placed on the roll section 330. It is designed to send out towards that direction.

[0036] The negative electrode plate cutting section 321 is provided between the negative electrode plate supply section 312 and the roll section 330, and the negative electrode The plate 20 is configured to be cut. The positive electrode plate cutting section 322 is connected to the positive electrode plate supply section 314. It is provided between the roll section 330 and is configured to cut the positive electrode plate 10. The cutting section 323 is provided between the roll section 330 and the winding section 340, and the roll section 330 The first separator 30 and the second separator 40, which are stacked together, are configured to be cut at once. Yes, they are. The roll section 330 has a pair of pressing rolls 331, and in the gap between these rolls Then, the first separator 30, the negative electrode plate 20, the second separator 40, and the positive electrode plate 10 are connected in this order. Repeatedly overlap them. The winding section 340 has a winding roll 341, and the roll section 330 is superimposed on the first The first separator 30, the negative electrode plate 20, the second separator 40, and the positive electrode plate 10 are wound into a cylindrical shape. It is configured to allow for this.

[0037] In the winding process S11 using this winding device 300, the first separator supply unit 311 is supplied The first separator 30 that was released, the negative electrode plate 20 that was sent out from the negative electrode plate supply unit 312, and the second The second separator 40 was sent out from the separator supply unit 313, and the positive electrode plate supply unit 314 The ejected positive electrode plates 10 each move toward the roll section 330. In the gap between the rolls of the pair of pressing rolls 331, the first separator 30, the negative electrode plate 20, and the The separator 40 and the positive electrode plate 10 are stacked in this order. Then, these are placed in the winding section 34 The material is wound into a cylindrical shape using the winding roll 341 to form the cylindrical wound electrode body 1Z. Then, The first separator end portion 30e is fixed to the cylindrical wound electrode body 1Z using adhesive tape (not shown). do.

[0038] At the end of the winding of the cylindrical wound electrode body 1Z, first the positive electrode plate 1 is cut by the positive electrode plate cutting portion 322. The 0 is cut. Next, the negative electrode plate cutting section 321 cuts the negative electrode plate from the positive electrode end portion 10e of the positive electrode plate 10. The negative electrode plate 20 is cut at a position where it becomes longer by a length ΔL1 (see Figure 1). Next, the separator The separator cutting portion 323 extends the first separator 30 and the negative electrode plate 20 beyond the negative electrode end portion 20e. The position where the second separator 40 is extended by a length ΔL2 (the positive terminal end of the positive electrode plate 10) The lengths of the first separator 30 and the second separator 40 are ΔL3 = ΔL1, respectively, compared to 10e. At a position where the length increases by +ΔL2 (see Figure 1), the first separator 30 and the second separator 4 Disconnect 0 simultaneously.

[0039] By cutting in this manner, the circumferential direction of the positive electrode end portion 10e in the cylindrical wound electrode body 1Z Position T1 and the circumferential position T3 of the end portion 30e of the first separator are related by a predetermined circumferential position relationship. It can be made related. In this embodiment, as shown in Figure 6, the circumferential direction of the positive electrode terminal portion 10e The angle θ from position T1 to the circumferential position T3 of the end portion 30e of the first separator is given by θ = +18 The temperature is set to 0 degrees. Furthermore, the first separator 30 and the second separator 40 are separated by the separator cutting section. By cutting simultaneously at 323, the circumferential position T3 of the end portion 30e of the first separator and the The circumferential position T4 of the separator end portion 40e is the same as the position of the separator end portion 40e.

[0040] Next, in the "pressing process" S12 of the electrode body manufacturing process S10, the press device 400 is used Then, the cylindrical wound electrode body 1Z described above is pressed and crushed to form a flattened wound electrode body 1 (see Figure 6). (Illuminate). In this pressing process S12, the positive electrode end portion 10e of the positive electrode plate 10 is formed by the flattened wound electrode body 1 Pressing is performed so that it is positioned within the flat portion 2. First, the cylindrical wound electrode body 1Z is placed on the lower mold 420. At that time, the first separator 30 1. The circumferential position T3 of the separator end portion 30e is a predetermined circumferential position TA (in this embodiment) Then, with the orientation being directly above, the cylindrical wound electrode body 1Z is placed on the lower mold 420.

[0041] Here, in the cylindrical wound electrode body 1Z, the positive electrode end portion 10e of the positive electrode plate 10 is the cylindrical wound electrode It is hidden inside the electrode body 1Z and cannot be seen from the radially outer side of the cylindrical wound electrode body 1Z. Therefore, the circumferential position T1 of the positive electrode end portion 10e can be determined from the appearance of the cylindrical wound electrode body 1Z. That is difficult. In contrast, in the aforementioned winding process S11, the circumferential position T1 of the positive electrode end portion 10e and the first The circumferential position T3 of the separator end portion 30e is in a predetermined circumferential positional relationship. Since the first separator terminal portion 30e is located on the outermost circumference of the cylindrical wound electrode body 1Z, it is radially outward It can be easily seen. Therefore, in the pressing process S12, the circle of the press device 400 The cylindrical wound electrode body 1Z is positioned such that the circumferential position T3 of the first separator end portion 30e is predetermined circumferentially By positioning it in a orientation such that the positive terminal portion TA is reached, the circumferential position T1 of the positive terminal portion 10e is It can be positioned at a predetermined circumferential position TB.

[0042] In this embodiment, in the winding process S11, from the circumferential position T1 of the positive electrode terminal portion 10e, The angle θ from the end portion 30e of the separator to the circumferential position T3 is set to +180 degrees. Therefore, Then, the circumferential position T3 of the end portion 30e of the first separator becomes the circumferential position TA (directly above position). In this position, the cylindrical wound electrode body 1Z is placed on the lower mold 420, and the circumference of the positive electrode terminal portion 10e The directional position T1 can be positioned at the circumferential position TB (the position directly below in this embodiment). Subsequently, the cylindrical wound electrode body 1Z is moved between the upper die 410 and the lower die 420 of the press device 400. It is flattened and crushed to form a flattened wound electrode body 1. As a result, the positive electrode terminal portion 10e is It is positioned approximately in the center of the electrode width direction BH of the flat portion 2 of the flat wound electrode body 1. Thus The positive electrode terminal portion 10e is positioned within the flat portion 2, and the lifting of the positive electrode terminal portion 10e is suppressed. A flattened, wound electrode body 1 is manufactured.

[0043] Next, in the "battery assembly process" S20 of the battery manufacturing process S1, the flat wound electrode body described above Assemble battery 100 using part 1. First, in the "terminal connection process" S21 of the battery assembly process S20, the case lid member 118 The positive terminal 120 and the negative terminal 130 are fixed to it (see Figure 1), and further the positive terminal 120 and the negative terminal The electrode terminal 130 is connected to the positive electrode exposed portion 10d of the positive electrode plate 10 and the negative electrode plate 20 of the flat wound electrode body 1. The positive terminal 120 and the negative terminal 130 are flattened and wound by welding to the negative electrode exposed portion 20d. It is electrically connected to electrode body 1.

[0044] Next, in the "containment process" S22, the flat wound electrode body 1 described above is placed in a bag-shaped insulating film 15 Wrap them in 0 and insert them into the case body member 117, and the case body member 117 The opening 117c is then closed with the case lid member 118. After that, the case body member 117 and the case lid The case 110 is formed by welding member 118 and the case lid member 118 around the entire circumference of the case lid member 118. The flat portion 2 of the flat wound electrode body 1 housed in case 110 is the first main portion of case 110 The electrode body is compressed in the thickness direction BH by the side portion 111 and the second main side portion 112. This more effectively suppresses the lifting of the positive electrode terminal portion 10e of the positive electrode plate 10. Next, in the "liquid injection process" S23, the electrolyte 140 is injected into the injection hole of the case lid member 118 (not shown). The liquid is injected into the case 110 through the (shown) and the injection hole is sealed with a sealing member (not shown). This involves performing initial charging, aging, and various tests on this battery 100. Thus, the battery 100 will be manufactured.

[0045] Next, in the "module assembly process" S2, multiple batteries 100 are stacked in the battery thickness direction FH. The layers are stacked and restrained by the restraining part 220 from the outside SH1 in the stacking direction SH, and the flat winding of each battery 100 is performed. A battery module 200 is assembled by compressing the flat portions 2 of the electrode body 1 in the electrode body thickness direction FH. To construct it, specifically, the battery 100 and spacer 215 are stacked alternately in the battery thickness direction FH. Then, a battery assembly 210 is formed, and further, on the outer SH1 of the stacking direction SH of the battery assembly 210 Then, the end plates 221 of the restraining part 220 are stacked on top of each other. After that, a pressing jig (not shown) Using this method, the battery assembly 210 and end plate 221 are positioned from the outside SH1 in the stacking direction SH. While applying pressure, the restraint bands 222 of the restraint section 220 are each placed over the end plates 221. And fix it in place to restrain the battery assembly 210. Next, connect the batteries 100 together using a busbar (not shown). Use this to make an electrical connection. Thus, the battery module 200 is completed.

[0046] As explained above, in the manufacturing method of the flat wound electrode body 1, after pressing, the positive electrode plate 10 The cylindrical wound electrode body 1Z is positioned such that the electrode terminal portion 10e is located within the flat portion 2 of the flat wound electrode body 1. Pressing is performed to form a flat wound electrode body 1. This is how any flat wound electrode body manufactured is formed. In the electrode body 1, the positive electrode end portion 10e of the positive electrode plate 10 is positioned within the flat portion 2 of the flat wound electrode body 1. Therefore, in any flat wound electrode body 1, the lifting of the positive electrode terminal portion 10e is prevented. This suppresses the unevenness of the distance between the positive electrode plate 10 and the negative electrode plate 20 near the positive electrode termination 10e. This can be suppressed.

[0047] Furthermore, in this embodiment, first in the winding process S11, the positive electrode end portion 10e of the positive electrode plate 10 The circumferential position T1 and the circumferential position T3 of the end portion 30e of the first separator 30. However, the cylindrical wound electrode body 1Z is formed so that it has a predetermined circumferential positional relationship. In the pressing process S12, the cylindrical wound electrode body 1Z is moved circumferentially to the end portion 30e of the first separator. The positive electrode is positioned so that the orientation T3 is a predetermined circumferential position TA, and then pressed. The end portion 10e is placed within the flat portion 2 of the flat wound electrode body 1. The first separator end portion 30e is It is located on the outermost circumference of the cylindrical wound electrode body 1Z and can be easily seen from the radially outer side. Therefore, by using the circumferential position T3 of the first separator end portion 30e as a reference, it is easy and The positive electrode terminal portion 10e can be reliably positioned within the flat portion 2 of the flat wound electrode body 1.

[0048] Furthermore, in the manufacturing method of the battery 100, the flat wound electrode body 1 manufactured in the electrode body manufacturing process S10 is used to assemble the battery 100. Therefore, in all batteries 100 manufactured, the lifting of the positive electrode terminal portion 10e is suppressed, and the unevenness of the inter-plate distance between the positive electrode plate 10 and the negative electrode plate 20 near the positive electrode terminal portion 10e is suppressed. 00 Even in this case, it is possible to suppress the occurrence of Li deposition near the portion of the negative electrode plate 20 that is located radially inward and opposite to the positive electrode terminal portion 10e.

[0049] Furthermore, the battery 100 manufactured in the battery manufacturing process S1 has a flat portion 2 of the flat wound electrode body 1. It is sandwiched between a pair of main side portions 111 and 112 of the S 110. Therefore, the positive electrode plate 10 The electrode terminal portion 10e is pressed from the outside, making the lifting of the positive electrode terminal portion 10e more effective. Because it is effectively suppressed, Li deposition caused by the lifting of the positive electrode terminal portion 10e is more effectively suppressed. It can be effectively suppressed.

[0050] Furthermore, in the manufacturing method of the battery module 200, the battery 100 manufactured in the battery manufacturing process S1 is We use this to manufacture the battery module 200. This is due to the lifting of the positive electrode terminal portion 10e in all batteries 100 included therein. i deposition is suppressed. Moreover, in this battery module 200, each battery 100 is constrained. The flat portions 2 of the flat wound electrode body 1 are each compressed in the electrode body thickness direction CH. Therefore, the positive electrode terminal portion 10e is pressed from the outside, and the positive electrode terminal portion 10e does not lift up. Because this is more effectively suppressed, Li deposition caused by the lifting of the positive electrode terminal portion 10e This can further suppress it.

[0051] Although the present invention has been described above in reference to embodiments, the present invention is not limited to these embodiments. It goes without saying that it is not a matter of fact, but rather something that can be modified and applied as appropriate, without deviating from its essence. do not have. [Explanation of Symbols]

[0052] 1 Flat wound electrode body 1Z Cylindrical wound electrode 2 Flat area 3 R section 10 Positive plate 10e Positive terminal end 20 Negative electrode plates 20e Negative terminal end 30 First Separator 30e First separator termination 40 Second Separator 40e Second separator termination 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 Pressing Machine CH electrode thickness direction FH Battery thickness direction SH stacking direction SH1 (outer side in the stacking direction) T1 (Circumferential position of the positive terminal) T3 (Circumferential position of the end of the first separator) TA,TB (predetermined) circumferential positions 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 Accommodation Process S23 Liquid injection process S2 Module Assembly Process

Claims

1. A flat wound electrode body is formed by winding a strip-shaped positive electrode plate and a strip-shaped negative electrode plate in a flat shape via a pair of strip-shaped separators, and having a flat portion and a pair of R-shaped portions located on both sides of the flat portion. Of the pair of separators, the first separator, which is the last to be wound, is wound longer than the positive electrode end portion of the positive electrode plate where the winding is finished. With respect to the positive electrode end portion, the length of the long winding of the first separator is such that, when the positive electrode end portion of the positive electrode plate is positioned in the center of the flat portion, the first separator end portion of the first separator is located in the center of the flat portion on the opposite side in the electrode thickness direction. The positive electrode termination portion is located in the center of the flat portion in the electrode width direction, The first separator terminal portion is located in the center of the electrode width direction, on the side of the flat portion opposite to the electrode thickness direction. Flat wound electrode body.

2. A flat wound electrode body according to Claim 1, The battery case comprises a pair of main side surfaces facing the flat portion of the flat wound electrode body, and the flat wound electrode body is housed in a state where the flat portion is sandwiched between the pair of main side surfaces. battery.

3. Multiple batteries according to claim 2 are stacked in the battery thickness direction connecting a pair of the main side portions, The flat portion of the flat wound electrode body of each of the batteries is compressed in the thickness direction of the electrode body by the restraining portion which is restrained from the outside in the stacking direction. Battery module.

4. A method for manufacturing a flat wound electrode body according to Claim 1, Of the pair of separators, the last separator to be wound is wound so that, with the positive electrode end of the positive electrode plate being the reference point, the positive electrode end of the positive electrode plate is positioned in the center of the flat portion, and the first separator end of the first separator is wound to a length that is on the opposite side in the electrode thickness direction and is positioned in the center of the flat portion. A method for manufacturing a flattened wound electrode body.

5. A method for manufacturing a battery according to Claim 2, The battery case includes a housing step of housing the flat wound electrode body in a state in which the flat portion is sandwiched between the pair of main side surfaces. Battery manufacturing method.

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