Method for manufacturing power storage module

Abstract

Provided is a method for manufacturing an electricity storage module with improved productivity. A method for manufacturing a power storage module includes a molding step for injection-molding a resin molded portion on a portion to be molded of a workpiece including an electrode laminate using an injection molding die, the molding step including: a warm-up position movement step for moving a second die supporting the workpiece to a warm-up position; a preheating step in which warm air flows through the formed warm air flow path after the preheating position moving step; a set position movement step in which, after the preheating step, a second mold supporting the workpiece is moved from the preheating position to the set position; a mold closing step of moving the third mold from the mold opening position to the mold closing position after the set position moving step; and a resin injection step of injecting, after the mold clamping step, a molten resin material to be a resin molded part into a molding space formed by the first mold, the second mold, the third mold, and the workpiece.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing a battery storage module. Background Technology

[0002] A known energy storage module has an electrode stack, which is formed by stacking multiple electrodes, including bipolar electrodes, along a stacking direction with spacers between them. The bipolar electrodes have a current collector, a positive electrode disposed on one side of the current collector, and a negative electrode disposed on the other side of the current collector. An example of a method for manufacturing such an energy storage module is disclosed in Patent Document 1.

[0003] Patent Document 1 describes a power storage module comprising: an electrode stack including a plurality of electrodes stacked in a first direction; and a sealing member surrounding the electrode stack when viewed from the first direction. Furthermore, the sealing member comprises: a first resin portion having a first communicating hole communicating with an internal space disposed between adjacent electrodes; and a second resin portion having a second communicating hole communicating with the first communicating hole. A method for manufacturing this power storage module includes: a first molding step in which a first insert mold having a first communicating hole forming portion for forming the first communicating hole is mounted on a mold, and the first resin portion is formed by resin molding of the mold; and a second molding step in which a second insert mold having a second communicating hole forming portion for forming the second communicating hole is mounted on the mold, and the second resin portion is formed by resin molding of the mold. In the second molding step, the second communicating hole forming portion is inserted relative to the first communicating hole to a position that does not penetrate the first communicating hole, and resin molding of the second resin portion is performed.

[0004] [Existing Technical Documents]

[0005] [Patent Literature]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2020-145030 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, large-sized energy storage modules have a structure that facilitates heat dissipation. Therefore, during the manufacturing process of such modules, after the workpiece, including the electrode stack, is placed in the mold, the resin-molded portion formed by injection molding does not easily heat up when molten resin is injected into the mold. Thus, if a large-sized energy storage module is manufactured using the method described in Patent Document 1, time is sometimes required for the product temperature to rise during the injection molding of the resin-molded portion. In this case, there is a problem of increased processing time and potentially reduced productivity.

[0009] This disclosure was made to solve such a problem, and its purpose is to provide a method for manufacturing an energy storage module that improves productivity.

[0010] Methods for solving problems

[0011] The method for manufacturing a battery storage module according to the embodiments includes a molding process in which a resin molding portion is injection molded into a workpiece comprising a plurality of electrodes stacked together using an injection molding die. The injection molding die includes: a first die; a second die capable of moving between a preheating position and a set position while supporting the workpiece, the preheating position forming a warm air flow path for heating the workpiece, the set position being closer to and located at the first die than the preheating position; and a third die capable of moving between a mold-closing position near the first die and a mold-opening position away from the first die. The molding process includes a preheating position moving step, which... The process includes: a second mold supporting the workpiece moving to the preheating position; a preheating process, which, after the preheating position moving process, causes the warm air to flow in the formed warm air flow path; a setting position moving process, which, after the preheating process, moves the second mold supporting the workpiece from the preheating position to the setting position; a mold closing process, which, after the setting position moving process, moves the third mold from the mold opening position to the mold closing position; and a resin injection process, which, after the mold closing process, injects resin material in a molten state into the forming space formed by the first mold, the second mold, the third mold, and the workpiece for forming the resin forming part.

[0012] Invention Effects

[0013] According to this disclosure, a method for manufacturing an energy storage module with improved productivity can be provided. Attached Figure Description

[0014] Figure 1 This is a perspective view showing a portion of an energy storage module manufactured by the energy storage module manufacturing method of Embodiment 1, and a cross-sectional view along line VV of the perspective view.

[0015] Figure 2 This is a flowchart illustrating a method for manufacturing an energy storage module according to Embodiment 1;

[0016] Figure 3 This is a schematic cross-sectional view used to illustrate the first intrusion position relocation process.

[0017] Figure 4This is a schematic cross-sectional view used to illustrate the preheating position movement process and the preheating process.

[0018] Figure 5 This is a schematic cross-sectional view used to illustrate the setting position moving process and the second intrusion position moving process.

[0019] Figure 6 It is a schematic cross-sectional view used to illustrate the mold closing process and the resin injection process. Detailed Implementation

[0020] Implementation Method 1

[0021] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments. Furthermore, for clarity, the following description and drawings have been appropriately simplified. The figures show only a part of the whole and actually include many other structures not shown. Additionally, in the following description, the same or equivalent elements are labeled with the same reference numerals, and repeated descriptions are omitted.

[0022] Figure 1 This is a perspective view showing a portion of an energy storage module manufactured by the energy storage module manufacturing method according to Embodiment 1, and a cross-sectional view along line VV of the perspective view. Figure 1 The energy storage module 10 shown is, for example, a bipolar battery having bipolar electrodes as described later. The energy storage module 10 is, for example, a nickel-metal hydride secondary battery, a lithium-ion secondary battery, or a double-layer capacitor. In the following description, a nickel-metal hydride secondary battery is used as an example.

[0023] The energy storage module 10 includes: an electrode stack 11 having multiple electrodes stacked on top of each other; a resin sealing portion 21 surrounding the electrode stack 11 when viewed from the stacking direction; and a resin molding portion 22 formed by resin injection molding. The energy storage module 10 has a rectangular shape when viewed from the stacking direction of the electrode stack 11. The electrode stack 11 includes multiple electrodes stacked in the stacking direction with spacers between them.

[0024] Multiple electrodes have multiple bipolar electrodes, a negative terminal electrode, and a positive terminal electrode. Each bipolar electrode has an electrode plate, a positive electrode disposed on one side of the electrode plate, and a negative electrode disposed on the other side of the electrode plate. The positive electrode is a layer of positive active material formed by coating a positive active material onto the electrode plate. The negative electrode is a layer of negative active material formed by coating a negative active material onto the electrode plate. In the electrode stack 11, the positive electrode of one bipolar electrode faces the negative electrode of another adjacent bipolar electrode in the stacking direction, separated by a separator. In the electrode stack 11, the negative electrode of one bipolar electrode faces the positive electrode of another adjacent bipolar electrode in the opposite stacking direction, separated by a separator.

[0025] The negative terminal electrode has an electrode plate and a negative electrode disposed on the other side of the electrode plate. The negative terminal electrode is disposed at one end in the stacking direction with its other side facing the center of the electrode stack 11. One side of the electrode plate of the negative terminal electrode constitutes an outer side surface of the electrode stack 11 in the stacking direction.

[0026] The positive terminal electrode has an electrode plate and a positive electrode disposed on one side of the electrode plate. The positive terminal electrode is disposed at the other end of the stacking direction with one side facing the center side of the electrode stack 11. The positive electrode disposed on one side of the positive terminal electrode is opposite to the negative electrode of the bipolar electrode at the other end of the stacking direction through a separator. The other side of the electrode plate of the positive terminal electrode constitutes another outer side surface of the electrode stack 11 in the stacking direction.

[0027] As the electrode plate, a rectangular metal foil may be used, for example. Specifically, nickel foil, plated steel plates, or plated stainless steel plates may be used as electrode plates. Furthermore, if the electrode plate is nickel foil, the nickel foil may also be plated. The periphery of the electrode plate (the periphery of the bipolar electrode) is rectangular, forming an uncoated area where neither the positive nor negative active material is coated. For example, nickel hydroxide may be used as the positive active material constituting the positive electrode. For example, a hydrogen storage alloy may be used as the negative active material constituting the negative electrode. The negative electrode formation area on the other side of the electrode plate may be larger than the positive electrode formation area on one side of the electrode plate.

[0028] The separator may be formed in the form of a sheet. Examples of separators include porous membranes made of polyolefin resins such as polyethylene (PE) and polypropylene (PP), and woven or nonwoven fabrics made of polypropylene, methylcellulose, etc. The separator may be a separator reinforced with a vinylidene fluoride resin compound. Furthermore, the separator is not limited to sheet form; bag-shaped separators may also be used.

[0029] The resin sealing portion 21 is, for example, integrally formed into a rectangular cylindrical shape. The resin sealing portion 21 is disposed on the side surface of the electrode laminate 11 extending in the lamination direction, surrounding the periphery of the electrode plate. The resin sealing portion 21 holds the periphery of the electrode plate on the side surface of the electrode laminate 11. The resin sealing portion 21 has multiple sealing members that respectively engage with the periphery of the electrode plate included in the electrode laminate 11.

[0030] The sealing member is continuously arranged around the entire periphery of the electrode plate, and appears as a rectangular frame when viewed from the stacking direction of the electrode stack 11. The sealing member can be provided not only on the electrode plates of the bipolar electrode, but also on the electrode plates of the negative terminal electrode and the positive terminal electrode.

[0031] The sealing member is fused to the periphery of the electrode plate, for example, by ultrasonic welding or thermoforming, to achieve an airtight seal. The sealing member is, for example, a film of a predetermined thickness in the lamination direction. The inner side of the sealing member is located further inward than the edge of the electrode plate. The outer side of the sealing member extends further outward than the edge of the electrode plate. Sealing members adjacent to each other along the lamination direction of the electrode stack 11 can be separated from each other or joined together. Furthermore, the outer edges of the sealing members can also be joined together by welding, for example, hot plate welding. The resin sealing portion 21 formed by the joining of the outer edges of the sealing members can adequately seal the electrode stack 11 when sealing the connecting hole 25 described later.

[0032] A resin-molded portion 22 is disposed on the outer side of the electrode laminate 11 and the resin sealing portion 21. The resin-molded portion 22 is disposed on one side portion 21a constituting the resin sealing portion 21. The side portion 21a extends in the direction of its short side, intersecting the lamination direction of the electrode laminate 11. The resin-molded portion 22 is formed of an insulating resin material capable of injection molding. The resin-molded portion 22 extends along the short side direction of the electrode laminate 11. The resin-molded portion 22 is formed in a frame shape covering the area in the side portion 21a where at least one of the plurality of connecting holes 25 (described later) is formed. The resin-molded portion 22 is fused to the outer surface of the resin sealing portion 21, for example, by heat during injection molding.

[0033] Multiple internal spaces V are provided within the electrode stack 11. Each internal space V is formed between multiple adjacent electrodes along the stacking direction. An internal space V is a space separated between adjacent electrode plates along the stacking direction of the electrode stack 11 by the electrode plates and the resin sealing portion 21. An electrolyte, such as an alkaline aqueous solution like potassium hydroxide, is contained within this internal space V. The electrolyte permeates the diaphragm, the positive electrode, and the negative electrode. Because the electrolyte is strongly alkaline, the resin sealing portion 21 and the resin molding portion 22 are made of a resin material resistant to strong alkalis.

[0034] Examples of resin materials used to form the resin sealing part 21 and the resin molding part 22 include polypropylene (PP), polyethylene (PE), polyphenylene sulfide (PPS), or modified polyphenylene ether (modified PPE).

[0035] The resin material constituting the resin sealing portion 21 and the resin material constituting the resin molding portion 22 are compatible with each other. Therefore, the resin sealing portion 21 and the resin molding portion 22 can be directly bonded to each other. In this embodiment, the resin material constituting the resin sealing portion 21 is PP, and the resin material constituting the resin molding portion 22 is PE.

[0036] A plurality of connecting holes 25 are formed on the side portion 21a of the resin sealing portion 21, communicating with each internal space V. Each connecting hole 25 communicates with a different internal space V. A plurality of connecting holes 26 are formed on the resin molding portion 22, communicating with each connecting hole 25. The connecting holes 26 communicate with the internal space V through the connecting holes 25.

[0037] The connecting holes 25 and 26 function as injection holes for injecting electrolyte into the internal space V. Additionally, after electrolyte injection, the connecting holes 25 and 26 become flow paths for the gas generated in the internal space V. The width of the connecting hole 25 (length of the connecting hole 25 in the stacking direction) and the width of the connecting hole 26 (length of the connecting hole 26 in the stacking direction) are, for example, the same.

[0038] The resin molding portion 22 has a plurality of protrusions 23 protruding from its outer surface 22a toward its long side, which intersects the lamination direction and the short side direction of the electrode laminate 11. Each protrusion 23 has a frame shape forming a plurality of openings 24. When electrolyte is injected into the internal space V, each protrusion 23 guides the electrolyte toward the connecting hole 26 and prevents electrolyte leakage to the outside. In addition, each protrusion 23 can function as a connecting protrusion for connecting pressure regulating valves, etc.

[0039] Viewed from the long side of the electrode stack 11, the protrusions 23 are arranged to surround each connecting hole 26. Each connecting hole 26 communicates with an opening 24 formed by the protrusions 23. The width of the opening 24 (the length of the opening 24 in the stacking direction) is greater than the width of the connecting hole 26 (the length of the connecting hole 26 in the stacking direction).

[0040] Next, refer to Figures 2-6 The manufacturing method of the energy storage module 10 is explained. Figure 2 This is a flowchart illustrating a method for manufacturing an energy storage module according to Embodiment 1. Figures 3-6 Indicated for explanation Figure 2 The flowchart shown is a schematic cross-sectional view of each step included in the forming process.

[0041] like Figure 2 As shown, the manufacturing method of the energy storage module 10 in Embodiment 1 includes a workpiece forming process (step S1) and a forming process (step S2).

[0042] The workpiece forming process is the process of forming a workpiece W that includes an electrode stack 11 having multiple electrodes stacked on top of each other. In this embodiment, as... Figure 3 As shown, an example of a process for forming a workpiece W, which includes a resin sealing portion 21 surrounding the electrode stack 11 when viewed from the stacking direction of the electrode stack 11, will be described.

[0043] In the workpiece forming process, a unit is fabricated by installing a sealing member and a separator that serve as a resin sealing portion 21 on the bipolar electrode. Similarly, a unit is fabricated by installing a sealing member and a separator that serve as a resin sealing portion 21 on the negative terminal electrode. A unit is fabricated by installing a sealing member that serves as a resin sealing portion 21 on the positive terminal electrode. Workpiece W is obtained by stacking these units. The workpiece W thus obtained has a resin sealing portion 21 surrounding the electrode stack 11 when viewed from the stacking direction of the electrode stack 11 bonded to the electrode stack 11 on which multiple electrodes are stacked.

[0044] Here, a connecting hole 25 is pre-formed on the sealing member. During the workpiece forming process, the workpiece W is formed with the connecting hole forming member 27 inserted into each connecting hole 25. The connecting hole forming member 27 is a member used to prevent blockage of the connecting holes 25 and is also used to form the connecting holes 26. Therefore, the number of connecting hole forming members 27 is the same as the number of connecting holes 25. The connecting hole forming member 27 is, for example, a metal plate. The shape of the connecting hole forming member 27 corresponds to the shape of the connecting holes 25 and 26. The front end of the connecting hole forming member 27 is inserted into the connecting hole 25, and the base end protrudes outward along the long side direction of the electrode laminate 11 towards the outside of the resin sealing portion 21. After injection molding of the resin molding portion 22, the connecting hole forming member 27 inserted into the connecting hole 25 is pulled out from the workpiece W, thereby preventing the connecting hole 25 from becoming blocked and forming the connecting hole 26.

[0045] Furthermore, during the workpiece forming process, the outer edges of multiple sealing members constituting the resin sealing portion 21 can be joined together by welding. When welding the outer edges of the sealing members together, for example, a hot plate can be pressed against the end face of the sealing member in a manner that avoids the connecting hole forming member 27 inserted into the connecting hole 25, so that the outer edges of the sealing members melt and are welded together.

[0046] Next, the molding process involves injecting a resin molding portion 22 into the workpiece W's molded portion using an injection molding die M. In this embodiment, the workpiece W includes a resin sealing portion 21 as the molded portion. Hereinafter, details of the molding process specific to the case where the molded portion of the workpiece W is the resin sealing portion 21 will be described. In the molding process, by... Figures 3-6 The injection molding die M shown is used for injection molding of the resin molding part 22.

[0047] An injection mold M is installed on an injection molding machine. The injection mold M is, for example, a metal mold. The injection mold M has... Figures 3-6 The lower mold 30 and the horizontal mold 40 are shown. In addition to the lower mold 30 and the horizontal mold 40, the injection molding die M also has… Figure 5 and Figure 6The upper mold 50 is shown. In addition to the injection molding mold M, the injection molding machine also has a lower mold moving mechanism for moving the lower mold 30, a workpiece horizontal mold moving mechanism for moving the workpiece W and the horizontal mold 40, and an upper mold moving mechanism for moving the upper mold 50.

[0048] In the following description, the mold closing direction of the injection molding die M, i.e., the moving direction of the upper die 50, is defined as the Z direction, and the direction intersecting the Z direction is defined as the X direction. In this embodiment, the Z direction is the vertical direction, and the X direction is the horizontal direction orthogonal to the Z direction.

[0049] The lower mold 30 is the first mold. In this embodiment, the lower mold 30 is movable between a set position away from the upper mold 50 along the X direction and a second intrusion position approaching the upper mold 50 along the X direction.

[0050] The lower mold 30 has an end 31 on one side in the X direction and an end 32 on the other side in the X direction. The end 31 has a forming surface 31a on its upper surface facing the forming space S. Additionally, the end 31 has a recess 31b formed on its upper surface for forming a warm air flow path P. The recess 31b is positioned adjacent to the forming surface 31a on the side opposite to the forming surface 31a in the X direction. Furthermore, the recess 31b is shaped to allow the lower end of the horizontal mold 40 to engage with it. The forming surface 31a and the recess 31b form a warm air flow path P between the workpiece W moving towards the preheating position and the horizontal mold 40 (see reference). Figure 4 ).

[0051] The end portion 32 has a vent 32a that communicates with the warm air flow path P. The vent 32a extends along the X direction with one end facing the warm air flow path P and the other end facing the outside of the lower mold 30. For example, warm air is supplied to the vent 32a from a warm air nozzle located outside the injection molding mold M. The warm air is supplied to the warm air flow path P via the vent 32a.

[0052] The horizontal mold 40 is a second mold that can support the workpiece W while moving between a preheating position that forms a warm air flow path P for heating the resin sealing part 21 and a setting position that is closer to the lower mold 30 than the preheating position and is set together with the workpiece W on the lower mold 30.

[0053] In this embodiment, the horizontal mold 40 can move along the X direction between a first intrusion position close to the lower mold 30 and a loading position away from the lower mold 30, and along the Z direction between the first intrusion position and a preheating position closer to the lower mold 30 than the first intrusion position.

[0054] The horizontal mold 40 has a molding surface 40a facing the molding space S on its lower end side. An insert mold 41 is detachably provided on the horizontal mold 40. The insert mold 41 is a mold for forming the resin molded part 22. The insert mold 41 is provided on the horizontal mold 40 such that its front end protrudes from the molding surface 40a of the horizontal mold 40 into the molding space S along the X direction. The insert mold 41 has a molding surface 41a facing the molding space S. A protrusion 23 (see reference) is formed on the molding surface 41a. Figure 1 The recess 41b is formed in the forming surface 41a. In addition, an insertion hole 41c is formed in the forming surface 41a for inserting the base end of the connecting hole forming member 27.

[0055] The upper mold 50 is a third mold that can move between a closed position near the lower mold 30 and an open position away from the lower mold 30. The upper mold 50 has a molding surface 50a on its lower surface facing the molding space S. The lower end of the injection nozzle 51 is inserted through the upper mold 50. The injection nozzle 51 injects molten resin R of the resin molding part 22 into the molding space S. The injection nozzle 51 extends in the Z direction with the injection port 51a formed at the front end (lower end) of the injection nozzle 51 facing the molding space S.

[0056] like Figure 2 As shown, the molding process includes a preheating position moving step (S2-2), a preheating step (S2-3), a setting position moving step (S2-4), a mold closing step (S2-6), and a resin injection step (S2-7). Furthermore, when the horizontal mold 40 can move between the first entry position and the loading position, and between the first entry position and the preheating position, the molding process also includes a first entry position moving step (S2-1) before the preheating step. And, when the lower mold 30 can move between the setting position and the second entry position, the molding process also includes a second entry position moving step (S2-5) after the setting position moving step and before the mold closing step.

[0057] First, refer to Figure 3 Explain the first intrusion location relocation process. Figure 3 This is a schematic cross-sectional view used to illustrate the first intrusion position relocation process. For example... Figure 3 As shown, the first intrusion position moving process is a process that moves the horizontal mold 40 supporting the workpiece W from the loading position to the first intrusion position before the preheating position moving process.

[0058] In the first intrusion position moving step, after the workpiece W, with the connecting hole forming member 27 inserted into the connecting hole 25, is set in the horizontal mold 40, the workpiece W and the horizontal mold 40 are pre-moved into the loading position within the injection molding machine. The workpiece W is supported by the horizontal mold 40 when it is set in the horizontal mold 40. Furthermore, the base end of the connecting hole forming member 27 is inserted into the insertion hole 41c of the insert mold 41 when the workpiece W is set in the horizontal mold 40. The horizontal mold 40 supports the workpiece W such that the long side direction of the electrode stack 11 aligns with the X direction and the stacking direction of the electrode stack 11 aligns with the Z direction. In the loading position, the workpiece horizontal mold moving mechanism is mounted on the workpiece W, for example, via a clamping member that clamps the workpiece W. Alternatively, this clamping member can be configured to clamp the horizontal mold 40 instead of the workpiece W. In this case, the workpiece horizontal mold moving mechanism is mounted on the horizontal mold 40 by means of the clamping member.

[0059] Then, the workpiece W and the transverse mold 40 are moved by the workpiece transverse mold moving mechanism along the direction from one side to the other in the X direction (by...). Figure 3 The hollow arrow in the diagram indicates the direction of movement (from the loading position to the first intrusion position). The workpiece W and the horizontal die 40 move towards the first intrusion position as shown in the diagram. Figure 3 The workpiece W is shown to penetrate above the lower mold 30. By positioning the workpiece W and the horizontal mold 40 in the first penetration position, the action of moving to the preheating position in the subsequent preheating process can be simplified into a simple action of lowering the workpiece W and the horizontal mold 40.

[0060] Next, refer to Figure 4 Explain the preheating position relocation process and the preheating process. Figure 4 This is a schematic sectional view used to illustrate the preheating position relocation process and the preheating process itself. For example... Figure 4 As shown, the preheating position moving process is the process of moving the horizontal mold 40 supporting the workpiece W to the preheating position. In the preheating position moving process, the workpiece horizontal mold moving mechanism is used to move the mold along a direction from one side (upper side) to the other side (lower side) in the Z direction. Figure 4 (The downward direction indicated by the hollow arrow) causes the workpiece W and the horizontal die 40 to move from the first entry position to the preheating position. The workpiece W and the horizontal die 40 move towards the preheating position, as... Figure 4 As shown, a warm air flow path P is formed between the forming surface 31a and the recess 31b of the lower mold 30.

[0061] The workpiece W and the horizontal mold 40 descend to a preheated position where the vent 32a formed in the lower mold 30 is not blocked by the horizontal mold 40. Therefore, the warm air flow path P formed after the preheated position moving process is connected to the vent 32a.

[0062] Next, the preheating process is the process of moving the preheating position after the preheating position movement process, in which the warm air flows through the formed warm air flow path P. In the preheating process, such as... Figure 4 As indicated by the black arrow, warm air supplied from the warm air nozzle to the vent 32a flows into the warm air flow path P. The warm air heats the lower mold 30 by flowing through the vent 32a. Furthermore, the warm air heats the resin sealing portion 21 of the workpiece W and the horizontal mold 40 by flowing through the warm air flow path P. This preheating process raises the temperature of the resin sealing portion 21 of the workpiece W, and also raises the mold temperatures of the horizontal mold 40 and the lower mold 30.

[0063] The temperature of the warm air supplied from the warm air nozzle is set according to the types of resin materials constituting the resin sealing part 21 and the resin molding part 22, so that the resin sealing part 21 of the workpiece W is at an appropriate preheating temperature. The temperature of the warm air can be adjusted by a temperature control unit such as a heater installed outside the injection molding mold M.

[0064] When the resin material constituting the resin sealing part 21 is PP and the resin material constituting the resin molding part 22 is PE, the temperature of the warm air supplied from the warm air nozzle is preferably, for example, 55°C or higher and 80°C or lower. When the temperature of the warm air supplied from the warm air nozzle is 55°C or higher, the resin materials constituting the resin sealing part 21 and the resin materials constituting the resin molding part 22 are well compatible, thus suppressing the degradation of the quality of the energy storage module 10 caused by incompatibility. In addition, when the temperature of the warm air supplied from the warm air nozzle is 80°C or lower, the degradation of the quality of the energy storage module 10 caused by the deterioration of the molded resin molding part 22 can be suppressed.

[0065] The warm air that has flowed through the warm air flow path P can also be reused. For example, the warm air that has flowed through the warm air flow path P flows from the gap formed between the workpiece W and the lower mold 30 in the X direction to the outside of the injection molding mold M, and is recovered by a recovery unit such as a recovery chamber located outside the injection molding mold M. Then, the recovered warm air is supplied from the warm air nozzle after its temperature is adjusted by the temperature control unit.

[0066] Next, refer to Figure 5 Explain the setting position movement process and the second intrusion position movement process. Figure 5 This is a schematic cross-sectional view used to illustrate the setting position movement process and the second intrusion position movement process. For example... Figure 5 As shown, the setting position moving process is a process that moves the horizontal mold 40 supporting the workpiece W from the preheating position to the setting position after the preheating process.

[0067] In the positioning and moving process, the workpiece horizontal die moving mechanism moves the workpiece along the Z-direction from one side (upper side) to the other side (lower side). Figure 5 (The downward direction indicated by the hollow arrow) causes the workpiece W and the horizontal die 40 to move from the preheated position to the set position. The workpiece W and the horizontal die 40 move towards the set position as if... Figure 5 The workpiece W and the horizontal mold 40 are positioned in the lower mold 30 as shown. With the workpiece W and the horizontal mold 40 positioned in the lower mold 30, the vent 32a is blocked by the horizontal mold 40. This stops the inflow of warm air into the warm air flow path P. Furthermore, with the workpiece W and the horizontal mold 40 positioned in the lower mold 30, the warm air flow path P is blocked by the horizontal mold 40 at the position between the forming surface 31a and the recess 31b of the lower mold 30. This suppresses the outflow of molten resin R into the forming space S during injection molding.

[0068] Next, the second intrusion position moving step is a step that moves the lower mold 30, on which the workpiece W and the horizontal mold 40 are set, from the set position to the second intrusion position after the set position moving step and before the mold closing step. In the second intrusion position moving step, the lower mold moving mechanism is used to move the lower mold along a direction from one side to the other in the X direction (…). Figure 5 (The direction of movement indicated by the hollow arrow) causes the lower mold 30, on which the workpiece W and the horizontal mold 40 are set, to move from the set position to the second intrusion position. The lower mold 30, on which the workpiece W and the horizontal mold 40 are set, moves towards the second intrusion position as... Figure 5 The lower mold 30 is positioned below the upper mold 50. By positioning the lower mold 30 in the second insertion position, the action of moving the mold to the mold closing position in the subsequent mold closing process can be simplified to a simple action of lowering the upper mold 50.

[0069] Next, refer to Figure 6 The molding process and resin injection process are explained. Figure 6 This is a schematic sectional view used to illustrate the mold-closing process and the resin injection process. For example... Figure 6 As shown, the mold closing process is the process of moving the upper mold 50 from the mold opening position to the mold closing position after the setting position moving process and the second intrusion position moving process.

[0070] In the mold closing process, the upper mold moving mechanism moves the mold along the Z-direction from one side (upper side) to the other side (lower side). Figure 6 (In the downward direction indicated by the hollow arrow), the upper mold 50 is moved from the mold-opening position to the mold-closing position. By moving to the mold-closing position, the upper mold 50 contacts the lower mold 30 and the horizontal mold 40, thus closing the injection molding mold M. In the closed state, with the lower mold 30, horizontal mold 40, and upper mold 50 combined, a forming space S is formed inside the injection molding mold M by the lower mold 30, horizontal mold 40, upper mold 50, and workpiece W.

[0071] The resin injection process is a process that, after the mold closing process, injects molten resin R into the molding space S, which is formed by the lower mold 30, the horizontal mold 40, the upper mold 50, and the workpiece W, to form the resin molding part 22. In the resin injection process, molten resin R is injected into the molding space S through an injection nozzle 51 inserted into the upper mold 50. The molten resin R injected from the injection nozzle 51 via the injection port 51a fills the molding space S. Thus, a resin molding part 22 with a shape corresponding to the shape of the molding space S is formed.

[0072] After the resin molding section 22 is cooled and solidified, the upper mold 50 is moved from the mold-closed position to the mold-open position by the upper mold moving mechanism, thereby opening the injection molding mold M. Then, after the lower mold 30, on which the molded workpiece W and the horizontal mold 40 are set, is moved from the second entry position to the set position by the lower mold moving mechanism, the molded workpiece W and the horizontal mold 40 are moved from the set position to the loading position via the first entry position by the workpiece horizontal mold moving mechanism. The horizontal mold 40 and the connecting hole forming member 27 are then removed from the molded workpiece W. In this way, the injection molding mold M can be demolded from the molded workpiece W.

[0073] After the injection molding die M is demolded from the molded workpiece, electrolyte is injected into the internal space V through the connecting holes 25 and 26 formed in the molded workpiece W. This manufactures the energy storage module 10. After the electrolyte is injected, the energy storage module 10 seals the connecting holes 25 and 26 through a pressure regulating valve or similar means.

[0074] Here, the large-sized energy storage module 10 has a structure that facilitates heat dissipation. Therefore, when manufacturing such an energy storage module 10, the resin molding portion 22 formed by injection molding does not easily heat up without preheating. Consequently, during the injection molding of the resin molding portion 22, time is sometimes required to raise the product temperature. In this case, there is a problem that the processing time from mold closing to resin injection becomes longer, potentially reducing productivity.

[0075] Therefore, a heating unit for heating the resin molding section 22 is considered. However, since the heat resistance temperature of the resin material constituting the resin molding section 22 is limited, for example, when a heating mechanism that raises the temperature of the resin molding section 22 to a temperature above its heat resistance temperature comes into direct contact with the resin material in injection molding, the molded resin molding section 22 may deteriorate. Therefore, methods that raise the product temperature by directly contacting a heating mechanism that raises the temperature of the resin molding section 22 to a temperature above its heat resistance temperature with the resin material in injection molding should be avoided.

[0076] In contrast, the manufacturing method of the energy storage module 10 according to this embodiment includes a molding step of using an injection molding die M to inject a resin molding part 22 into the resin sealing part 21 (the part to be molded) of a workpiece W comprising an electrode stack 11 consisting of multiple electrodes.

[0077] The injection molding die M includes: a lower die 30 (first die); a horizontal die 40 (second die) which can move between a preheating position that forms a warm air flow path P for heating the resin seal 21 and a setting position that is closer to the lower die 30 and set in the lower die 30 while supporting the workpiece W; and an upper die 50 (third die) which can move between a mold closing position close to the lower die 30 and a mold opening position away from the lower die 30.

[0078] The molding process includes: a preheating position moving process, in which the horizontal mold 40 supporting the workpiece W is moved to a preheating position; and a preheating process, in which warm air flows in the formed warm air flow path P after the preheating position moving process. Furthermore, the molding process includes: a setting position moving process, in which the horizontal mold 40 supporting the workpiece W is moved from the preheating position to a setting position after the preheating process; and a mold closing process, in which the upper mold 50 is moved from the mold opening position to the mold closing position after the setting position moving process. Moreover, the molding process includes a resin injection process, after the mold closing process, injecting molten resin R (molten resin material) to be the resin molding part 22 into the molding space S formed by the lower mold 30, the horizontal mold 40, the upper mold 50, and the workpiece W.

[0079] According to the manufacturing method of such a power storage module 10, by preheating the resin sealing portion 21 of the workpiece W by flowing warm air through the warm air flow path P just before mold closing, the product temperature during injection molding of the resin sealing portion 21 into the resin molding portion 22 can rise rapidly in a short time. Furthermore, by preheating the horizontal mold 40 by flowing warm air through the warm air flow path P just before mold closing, the mold temperature during injection molding can be maintained at a temperature suitable for injection molding. As a result, the processing time from mold closing to resin injection is shortened.

[0080] Therefore, according to this embodiment, a method for manufacturing an energy storage module 10 with improved productivity can be provided.

[0081] In addition, in the above-described method for manufacturing the energy storage module 10, the workpiece W preferably includes a resin sealing portion 21 that surrounds the electrode stack 11 when viewed from the stacking direction as a forming portion.

[0082] With this structure, the resin material constituting the resin sealing part 21 and the resin material constituting the resin molding part 22 are well compatible, thus suppressing the decline in the quality of the energy storage module 10 caused by incompatibility.

[0083] In addition, in the above-described method for manufacturing the energy storage module 10, it is preferable that at least one of the lower mold 30 and the upper mold 50 has a vent 32a that communicates with the warm air flow path P, and warm air is supplied to the warm air flow path P through the vent 32a.

[0084] According to this structure, by preheating the mold with vent 32a by directing warm air toward vent 32a just before mold closing, the mold temperature during injection molding can be maintained at a temperature suitable for injection molding.

[0085] Furthermore, in the above-described method for manufacturing the energy storage module 10, the horizontal mold 40 can move between a first entry position close to the lower mold 30 and a loading position away from the lower mold 30 along a direction intersecting the movement direction of the upper mold 50, and between the first entry position and a preheating position closer to the lower mold 30 than the first entry position along a direction parallel to the movement direction of the upper mold 50. Moreover, the forming process preferably includes a first entry position moving step, prior to the preheating position moving step, in which the horizontal mold 40 supporting the workpiece W is moved from the loading position to the first entry position.

[0086] With this structure, by positioning the workpiece W and the horizontal die 40 at the first intrusion position, the subsequent preheating process following the movement at the first intrusion position can be simplified until the workpiece moves to the preheating position.

[0087] Furthermore, in the above-described method for manufacturing the energy storage module 10, the lower mold 30 is capable of moving between a set position away from the upper mold 50 in a direction intersecting the moving direction of the upper mold 50 and a second intrusion position approaching the upper mold 50 in a direction intersecting the moving direction of the upper mold 50. Preferably, the forming process includes a second intrusion position moving process, which moves the lower mold 30, on which the workpiece W and the horizontal mold 40 are set, from the set position to the second intrusion position after the set position moving process and before the mold closing process.

[0088] With this structure, by positioning the lower mold 30 at the second intrusion position, the movement from the next mold closing step after the moving step at the second intrusion position to the mold closing position can be simplified.

[0089] Furthermore, this disclosure is not limited to the above-described embodiments and can be appropriately modified without departing from the spirit of the matter. For example, in the above embodiments, a molding process embodied in the case where the molded portion of the workpiece W is the resin sealing portion 21 has been described, but it is not limited thereto. The molded portion of the workpiece W may, for example, be part of the electrode laminate 11.

[0090] Furthermore, in the above embodiments, the molding process including the first intrusion position movement process, the preheating position movement process, the preheating process, the setting position movement process, the second intrusion position movement process, the mold closing process, and the resin injection process has been described, but it is not limited thereto. At least one of the first intrusion position movement process and the second intrusion position movement process may be omitted.

[0091] Explanation of reference numerals in the attached figures

[0092] 10. Energy Storage Module

[0093] 11 Electrode laminate

[0094] 21 Resin sealing part 21a Side

[0095] 22 Resin molding part 22a outer surface

[0096] 23 Protrusion 24 Opening

[0097] 25 and 26 connecting holes

[0098] 27 Connecting Hole Forming Component

[0099] 30 Lower Mold

[0100] 31 end portion 31a forming surface 31b concave portion

[0101] 32 End 32a Ventilation opening

[0102] 40 horizontal die 40a forming surface

[0103] 41 Embedded mold 41a Forming surface 41b Recess 41c Insertion hole

[0104] 50 upper mold 50a forming surface

[0105] 51 injection nozzle 51a injection port

[0106] M Injection Molding Mold P Warm Air Flow Path

[0107] R is the molten resin, S is the forming space, V is the internal space, and W is the workpiece.

Claims

1. A method of manufacturing an electricity storage module, comprising a molding process that molds a resin molding portion using an injection molding mold, the resin molding portion being formed in a molded portion of a work including an electrode laminate in which a plurality of electrode layers are stacked, the injection molding mold having: a first mold; A second mold capable of moving between a preheating position, which forms a warm air flow path for warm air used to warm the formed portion, and a set position, which is closer to the first mold than the preheating position and is set at the first mold, while supporting the workpiece; and a third mold that is movable between a mold clamped position that approaches the first mold and a mold opened position that is away from the first mold, the molding process including: a preheating position moving process that moves the second mold that supports the work to a preheating position; a preheating process that causes the warm air to flow in the warm air flow path formed after the preheating position moving process; a setting position moving process that moves the second mold that supports the work from the preheating position to a setting position after the preheating process; a mold clamping process that moves the third mold from the mold opened position to the mold clamped position after the setting position moving process; and a resin injecting process that injects a resin material in a molten state that is to be the resin molding portion into a molding space for molding the resin molding portion formed by the first mold, the second mold, the third mold, and the work after the mold clamping process.

2. The method of manufacturing an electricity storage module according to claim 1, wherein the work includes a resin sealing portion that surrounds the electrode laminate as the molded portion as viewed from a stacking direction of the electrode laminate.

3. The method of manufacturing an electricity storage module according to claim 1, wherein at least one of the first mold and the third mold is formed with a vent that communicates with the warm air flow path, the warm air is supplied to the warm air flow path via the vent.

4. The method of manufacturing an electricity storage module according to claim 1, wherein the second mold is movable along a direction that intersects with a moving direction of the third mold between a first intrusion position that approaches the first mold and a carrying-in position that is away from the first mold, and is movable along a direction that is parallel to the moving direction of the third mold between the first intrusion position and the preheating position that is closer to the first mold than the first intrusion position, the molding process includes a first intrusion position moving process that moves the second mold that supports the work from the carrying-in position to the first intrusion position before the preheating position moving process.

5. The method of manufacturing an electricity storage module according to claim 1, wherein the first mold is movable between the setting position that is away from the third mold along a direction that intersects with a moving direction of the third mold and a second intrusion position that approaches the third mold along a direction that intersects with the moving direction of the third mold, the second mold is movable between the setting position that is away from the third mold along a direction that intersects with a moving direction of the third mold and the preheating position that is closer to the third mold along a direction that intersects with the moving direction of the third mold. The molding process includes a second intrusion position moving process that moves the first die in which the workpiece and the second die are set from the set position to a second intrusion position after the set position moving process and before the die closing process.

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