Method for manufacturing bipolar storage battery

Abstract

The present invention addresses the problem of preventing a short circuit in a battery when a conductive adhesive is applied to a conductive part of a power storage module. A method for manufacturing a bipolar storage battery in which a plurality of power storage modules are stacked, the method comprising: a coating step in which a conductive adhesive is applied to a fully charged power storage module that has been activated using a coating device, and the electrically conductive adhesive is applied to the fully charged power storage module; the coating step includes a step of intermittently discharging the conductive adhesive from the coating device so that the coating device and the power storage module are not connected by the conductive adhesive, and coating the conductive adhesive on the conductive portion of the power storage module.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a bipolar storage battery. Background Technology

[0002] Patent document 1 discloses the following: a bipolar battery in which a stack of alternating energy storage modules and conductive plates is constrained by a constraint plate and fastening components, wherein multiple energy storage modules are connected in series via conductive plates, and refrigerant circulates inside the conductive plates.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2021-012755 Summary of the Invention

[0004] For a laminate containing a storage module and a conductive plate, as described in Patent Document 1, a conductive adhesive can be used to bond the storage module and the conductive plate, using the adhesive force of the conductive adhesive to constrain the laminate. In manufacturing this bipolar battery, a coating apparatus is used to apply the conductive adhesive to the storage module.

[0005] If a conductive adhesive is applied to the battery module using a contact coating method such as screen printing, the coating device and the battery module are electrically connected via the conductive adhesive. In this case, if the battery module is in an activated, fully charged state, the conductive adhesive will conduct electricity from the coating device to the grounding wire, forming a closed circuit, which could potentially cause a short circuit in the battery.

[0006] The present invention was made in view of the above circumstances, and its object is to provide a method for manufacturing a bipolar battery that can prevent short circuits of the battery when a conductive adhesive is applied to the conductive part of the storage module.

[0007] This invention relates to a method for manufacturing a bipolar battery, wherein the bipolar battery is composed of multiple stacked energy storage modules. The method for manufacturing the bipolar battery is characterized by comprising: a coating step, wherein a conductive adhesive is applied to activated, fully charged energy storage modules using a coating device; the coating step includes intermittently discharging the conductive adhesive from the coating device to prevent the coating device from being connected to the energy storage modules by the conductive adhesive; and a step of applying the conductive adhesive to the conductive portion of the energy storage modules.

[0008] Invention Effects

[0009] In this invention, short circuits in the battery can be prevented when a conductive adhesive is applied to the conductive portion of the energy storage module. Attached Figure Description

[0010] Figure 1 This is a schematic diagram illustrating a bipolar battery in an embodiment.

[0011] Figure 2 This is a diagram showing the state of conductive adhesive applied to the battery module.

[0012] Figure 3 This is a diagram used to illustrate the coating process.

[0013] Figure 4 This is a diagram used to illustrate the equipment used in the coating process.

[0014] Figure 5 This is a diagram used to illustrate the manufacturing method of the bipolar battery in the comparative example. Detailed Implementation

[0015] The manufacturing method of the bipolar storage battery in the embodiments of the present invention will be described in detail below.

[0016] Furthermore, the present invention is not limited to the embodiments described below.

[0017] Figure 1 This is a schematic diagram illustrating a bipolar battery in an embodiment. The bipolar battery 1 includes a storage module 2, a casing 3, a cooler 4, a current collector 5, and a conductive adhesive 6.

[0018] A bipolar battery 1 has a structure in which multiple energy storage modules 2 are stacked. Each energy storage module 2 comprises multiple battery cells, each including bipolar electrodes. The energy storage module 2 has an electrode stack with stacked bipolar electrodes. For example... Figure 2 , Figure 3 As shown, the energy storage module 2 is formed into a rectangular shape when viewed from above. The energy storage module 2 has a conductive part 11 and a non-conductive part 12.

[0019] The conductive portion 11 is the part that is electrically connected to the bipolar electrodes. The conductive portion 11 is made of metal. The non-conductive portion 12 is the part through which current does not flow. The non-conductive portion 12 is made of resin. The non-conductive portion 12 is formed to surround the outer periphery of the conductive portion 11. The outer frame of the energy storage module 2 is formed by the non-conductive portion 12. Figure 2 As shown, conductive adhesive 6 is applied to the conductive portion 11, but not to the non-conductive portion 12. For example, the conductive adhesive 6 is applied in a linear manner extending along a predetermined direction on the surface of the conductive portion 11, and is arranged in multiple rows throughout the conductive portion 11.

[0020] The housing 3 houses the energy storage module 2, the cooler 4, and the current collector 5. The housing 3 includes a lower metal housing 7. The cooler 4 is a metal plate-shaped component for cooling the energy storage module 2. The current collector 5 is also a metal plate-shaped component. A refrigerant flow path is provided inside the cooler 4. The energy storage module 2 is cooled by allowing the refrigerant to flow through this internal flow path.

[0021] Inside the housing 3, adjacent energy storage modules 2 are arranged with coolers 4 between them in the stacking direction. The energy storage modules 2 and coolers 4 are stacked alternately in the stacking direction. Inside the housing 3, the energy storage modules 2 are bonded to the coolers 4 via conductive adhesive 6, and the current collector 5 is bonded to the energy storage modules 2 via conductive adhesive 6. The current collector 5 is electrically connected to the energy storage modules 2 via conductive adhesive 6. The bipolar battery 1 includes a pair of current collectors, including a current collector on the positive electrode side and a current collector on the negative electrode side. The current collector 5 is either one of the pair of current collectors. The pair of current collectors are configured to sandwich the stacked assembly of the energy storage modules 2 and the coolers 4. In the stacked assembly of the energy storage modules 2 and the coolers 4, energy storage modules 2 are arranged at both ends in the stacking direction. The energy storage modules 2 arranged at both ends in this stacking direction are bonded to the current collectors via conductive adhesive 6.

[0022] The conductive adhesive 6 is a two-component adhesive that cures by mixing two liquids: a base agent containing filler and epoxy resin, and an amine-based curing agent. In the laminate containing the energy storage module 2, the cooler 4, and the current collector 5, the energy storage module 2 and the cooler 4 are electrically connected via the conductive adhesive 6, and the cooler 4 and the current collector 5 are also electrically connected via the conductive adhesive 6. Adjacent energy storage modules 2 are electrically connected to each other in the lamination direction of the laminate. Furthermore, the bipolar battery 1 has a structure in which the layers are bound together by the adhesive force of the conductive adhesive 6.

[0023] The manufacturing method of the bipolar battery 1 includes a coating process and a lamination process.

[0024] The coating process involves applying conductive adhesive 6 to the activated, fully charged battery module 2. The conductive adhesive 6 is applied to the conductive portion 11 of the battery module 2.

[0025] like Figure 3 As shown, in the coating process, conductive adhesive 6 is intermittently discharged from the coating apparatus 20, ensuring that the coating apparatus 20 and the battery module 2 are not connected by the conductive adhesive 6, and the conductive adhesive 6 is applied to the conductive portion 11 of the battery module 2. This coating process is performed using non-contact coating, ensuring that the coating apparatus 20 and the battery module 2 are not electrically connected by the conductive adhesive 6. Non-contact coating refers to coating in a state where the coating apparatus 20 and the battery are not connected by the conductive adhesive 6. The coating apparatus 20 is, for example, composed of a spray dispenser.

[0026] like Figure 4 As shown, the coating apparatus 20 is connected to a main agent pipeline 21 and a curing agent pipeline 22, which respectively supply the main agent and curing agent as liquid agents before mixing. The coating apparatus 20 is installed in the equipment 30. The equipment 30 includes the coating apparatus 20, the main agent tank 31, the main agent pump 32, the curing agent tank 33, the curing agent pump 34, and the distributor 35.

[0027] The base agent pump 32 pumps the base agent from the base agent tank 31 to the distributor 35. The base agent pump 32 is connected to the distributor 35 via piping 36. The curing agent pump 34 pumps the curing agent from the curing agent tank 33 to the distributor 35. The curing agent pump 34 is connected to the distributor 35 via piping 37. The adhesive piping of the coating device 20 is connected to the distributor 35. The base agent piping 21 connects the distributor 35 and the coating device 20, and supplies the base agent to the coating device 20. The curing agent piping 22 connects the distributor 35 and the coating device 20, and supplies the curing agent to the coating device 20.

[0028] Thus, during the coating process, conductive adhesive 6 is intermittently applied to the conductive portion 11 of the active battery. An active battery refers to a battery that has been activated, has voltage, and is fully charged. The energy storage module 2 described in this specification is an active battery. Intermittent coating prevents the active battery from becoming electrically connected to the coating apparatus 20 via the conductive adhesive 6.

[0029] like Figure 5 As shown, in the manufacturing method of the comparative example, conductive adhesive 6 is continuously discharged from the coating apparatus 20. In this comparative example, during the coating process, the conductive adhesive 6 present between the coating apparatus 20 and the live battery drips to connect the coating apparatus 20 and the live battery, thus electrically connecting the coating apparatus 20 and the live battery via the conductive adhesive 6. Coating in the state where the coating apparatus 20 and the live battery are connected by the conductive adhesive 6 is described as contact coating. In contact coating, a closed circuit 100 is formed, including the live battery, the coating apparatus 20, the grounding wire, and the live battery. If a closed circuit 100 is formed, it will cause a short circuit in the battery.

[0030] In contrast, according to the coating process of the embodiment, by intermittently discharging the conductive adhesive 6 through the conductive part 11, the conductive adhesive 6 can be applied while protecting the energy storage module 2, which is a live battery, without forming a closed circuit 100 as in the comparative example.

[0031] In the bipolar battery 1, a storage module 2 and a metal plate-like component are stacked, and the layers are connected by a conductive adhesive 6. In the stacked body containing the storage module 2 and the metal plate-like component, the adhesive force of the conductive adhesive 6 binds the layers together. Therefore, if the conductive adhesive 6 does not cure, the process cannot proceed to the next step.

[0032] Therefore, the coating process includes a heating process that heats the base agent and curing agent before mixing and heats the battery module 2. In the heating process, the base agent piping 21 and curing agent piping 22, which are adhesive piping of the coating apparatus 20, are heated, and the battery module 2, which is a live battery, is heated by the heater 40. A heater is built into the base agent piping 21. The base agent is heated by the heater built into the base agent piping 21. A heater is built into the curing agent piping 22. The curing agent is heated by the heater built into the curing agent piping 22. Then, in the coating process, a conductive adhesive 6, formed by mixing and heating the base agent and curing agent, is intermittently discharged from the coating apparatus 20, and the conductive adhesive 6 is applied to the conductive portion 11 of the heated battery module 2. By heating based on the coating process, the curing of the adhesive after the two-component mixture can be promoted, shortening the cycle time.

[0033] The lamination process involves laminating the energy storage module 2, on which a conductive adhesive 6 is applied, onto the conductive portion 11. The lamination process includes the following steps: bonding the energy storage module 2 and the cooler 4 using the conductive adhesive 6, establishing an electrical connection via the conductive adhesive 6, and laminating the energy storage module 2 and the cooler 4 via the conductive adhesive 6. Through the lamination process, a laminated body is formed, constrained by the adhesive force of the conductive adhesive 6.

[0034] As explained above, according to the embodiment, since the conductive adhesive 6 is intermittently discharged from the coating apparatus 20, a closed circuit 100 through the device 30 and the grounding wire is not formed, and the conductive adhesive 6 can be coated onto the live battery, thus preventing short circuits in the battery.

[0035] Furthermore, by heating the conductive adhesive 6 and the energy storage module 2, which serves as the workpiece to be coated, the curing of the adhesive after the two liquids are mixed can be promoted. As a result, the cycle time can be shortened.

[0036] Symbol Explanation

[0037] 1-Bipolar battery, 2-Storage module, 3-Housing, 4-Cooler (plate-shaped component), 5-Current collector (plate-shaped component), 6-Conductive adhesive, 7-Lower housing, 11-Conductive part, 12-Non-conductive part, 20-Coating device, 30-Equipment, 40-Heater.

Claims

1. A method for manufacturing a bipolar battery, wherein the bipolar battery is composed of multiple stacked energy storage modules, the method being characterized by comprising: In the coating process, a conductive adhesive is applied to the activated, fully charged battery module using a coating device. The coating process includes the steps of intermittently discharging the conductive adhesive from the coating device to prevent the coating device from being connected to the energy storage module by the conductive adhesive, and applying the conductive adhesive to the conductive part of the energy storage module.

2. The method for manufacturing a bipolar storage battery according to claim 1, characterized in that, The conductive adhesive is a two-component mixed adhesive that is cured by mixing two liquids: a base agent containing fillers and epoxy resin, and an amine curing agent. The coating process includes the following steps: The main agent and the curing agent before mixing are heated, and the energy storage module is also heated; and The conductive adhesive, which is a mixture of the heated main agent and the curing agent, is intermittently discharged from the coating device, and the conductive adhesive is applied to the conductive portion of the heated energy storage module.

3. The method for manufacturing a bipolar storage battery according to claim 2, characterized in that, include: In the lamination process, the energy storage module and the plate-shaped component, on which the conductive portion is coated with the conductive adhesive, are bonded together by the conductive adhesive, and are electrically connected via the conductive adhesive, and the energy storage module and the plate-shaped component are laminated via the conductive adhesive.

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