Manufacturing method for bipolar batteries

Abstract

To prevent short circuits in the battery when applying conductive adhesive to the conductive parts of the energy storage module. [Solution] A method for manufacturing a bipolar battery in which multiple energy storage modules are stacked, comprising a coating step of applying a conductive adhesive 6 to an activated and charged energy storage module 2 using a coating device 20, wherein the coating step includes a step of applying the conductive adhesive 6 to the conductive portion 11 of the energy storage module 2 by intermittently discharging the conductive adhesive 6 from the coating device 20 so that the coating device 20 and the energy storage module 2 are not connected by the conductive adhesive 6.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a bipolar battery.

Background Art

[0002] Patent Document 1 discloses a bipolar battery in which a laminate in which power storage modules and conductive plates are alternately laminated is constrained by a restraining plate and fastening members, and a plurality of power storage modules are electrically connected in series via the conductive plates, and a refrigerant flows inside the conductive plates.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Regarding a laminate in which a power storage module and a conductive plate are laminated as in the configuration described in Patent Document 1, it is conceivable to join the power storage module and the conductive plate using a conductive adhesive and constrain the laminate by the adhesive force of the conductive adhesive. When manufacturing such a bipolar battery, a conductive adhesive is applied to the power storage module using a coating device.

[0005] At that time, when the conductive adhesive is applied to the power storage module by contact coating such as screen printing, the coating device and the battery module are electrically connected via the conductive adhesive. In this case, if the power storage module is in an activated and charged state, current flows from the coating device to the ground wire through the conductive adhesive, forming a closed circuit and potentially causing a battery short circuit.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a method for manufacturing a bipolar battery that can prevent short circuits in the battery when applying a conductive adhesive to the energy storage module. [Means for solving the problem]

[0007] The present invention relates to a method for manufacturing a bipolar battery comprising a plurality of stacked energy storage modules, comprising a coating step of applying a conductive adhesive to activated and charged energy storage modules using a coating device, wherein the coating step includes a step of applying the conductive adhesive to the conductive portions of the energy storage modules by intermittently discharging the conductive adhesive from the coating device so that the coating device and the energy storage modules are not connected by the conductive adhesive. [Effects of the Invention]

[0008] In this invention, it is possible to prevent short circuits in the battery when applying a conductive adhesive to the energy storage module. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing a bipolar battery in an embodiment. [Figure 2] This diagram shows the state after conductive adhesive has been applied to the energy storage module. [Figure 3] This is a diagram illustrating the coating process. [Figure 4] This is a diagram illustrating the equipment used in the coating process. [Figure 5] This is a diagram illustrating the manufacturing method of a bipolar battery in a comparative example. [Modes for carrying out the invention]

[0010] The following describes in detail the method for manufacturing a bipolar battery according to embodiments of the present invention. However, the present invention is not limited to the embodiments described below.

[0011] Figure 1 is a schematic diagram showing a bipolar battery in an embodiment. The bipolar battery 1 comprises a storage module 2, a case 3, a cooler 4, a current collector plate 5, and a conductive adhesive 6.

[0012] The 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 containing bipolar electrodes. The energy storage module 2 has an electrode stack in which the bipolar electrodes are stacked. As shown in Figures 2 and 3, the energy storage module 2 is formed in a rectangular shape in plan view. The energy storage module 2 has a conductive portion 11 and a non-conductive portion 12.

[0013] The conductive portion 11 is the part that is electrically connected to the bipolar electrode. The conductive portion 11 is made of metal. The non-conductive portion 12 is the part that does not conduct current. The non-conductive portion 12 is made of resin. The non-conductive portion 12 is formed so as to surround the outer circumference of the conductive portion 11. The outer frame of the energy storage module 2 is formed by the non-conductive portion 12. As shown in Figure 2, 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 to the surface of the conductive portion 11 so as to extend linearly along a predetermined direction, and is provided to form multiple rows over the entire conductive portion 11.

[0014] Case 3 houses the energy storage module 2, the cooler 4, and the current collector plate 5. Case 3 includes a metal lower case 7. The cooler 4 is a metal plate-shaped component that cools the energy storage module 2. The current collector plate 5 is a metal plate-shaped component. A flow path for refrigerant is provided inside the cooler 4. The energy storage module 2 is cooled by flowing refrigerant through the flow path inside the cooler 4.

[0015] Inside case 3, a cooler 4 is positioned between adjacent energy storage modules 2 in the stacking direction. The energy storage modules 2 and coolers 4 are stacked alternately in the stacking direction. Inside case 3, the energy storage modules 2 are joined to the coolers 4 by conductive adhesive 6, and the current collector plates 5 are joined to the energy storage modules 2 by conductive adhesive 6. The current collector plates 5 are electrically connected to the energy storage modules 2 via the conductive adhesive 6. The bipolar battery 1 includes a pair of current collector plates, including a positive electrode current collector plate and a negative electrode current collector plate. The current collector plate 5 is one of the pair of current collector plates. The pair of current collector plates are positioned to sandwich the stacked body in which the energy storage modules 2 and coolers 4 are stacked. In the stacked body in which the energy storage modules 2 and coolers 4 are stacked, energy storage modules 2 are positioned at both ends in the stacking direction. The energy storage modules 2 positioned at both ends in the stacking direction are joined to the current collector plates by conductive adhesive 6.

[0016] The conductive adhesive 6 is a two-component adhesive that hardens when two components are mixed: a main component containing a filler and epoxy resin, and an amine-based curing agent. In a laminate formed by stacking energy storage modules 2, a cooler 4, and a current collector plate 5, the energy storage modules 2 and the cooler 4 are electrically connected by the conductive adhesive 6, and the cooler 4 and the current collector plate 5 are electrically connected by the conductive adhesive 6. Adjacent energy storage modules 2 in the stacking direction of the laminate are electrically connected to each other. Furthermore, the bipolar battery 1 has a structure in which the layers are constrained by the adhesive force of the conductive adhesive 6.

[0017] The manufacturing method for the bipolar battery 1 includes a coating step and a lamination step.

[0018] The coating process involves applying a conductive adhesive 6 to the activated and charged energy storage module 2. The area to which the conductive adhesive 6 is applied is the conductive portion 11 of the energy storage module 2.

[0019] As shown in FIG. 3, in the coating process, the conductive adhesive 6 is intermittently discharged from the coating device 20, and the conductive adhesive 6 is applied to the conduction part 11 of the power storage module 2 so that the coating device 20 and the power storage module 2 are not connected by the conductive adhesive 6. This coating process is performed by non-contact coating so that the coating device 20 and the power storage module 2 are not electrically connected by the conductive adhesive 6. Non-contact coating means coating in a state where the coating device 20 and the active battery are not connected by the conductive adhesive 6. The coating device 20 is constituted by, for example, a jet dispenser.

[0020] As shown in FIG. 4, the coating device 20 is connected to a main agent pipe 21 and a curing agent pipe 22 that supply the main agent and the curing agent, which are the liquid agents before mixing, respectively. The coating device 20 is provided in the facility 30. The facility 30 includes the coating device 20, a main agent tank 31, a main agent pump 32, a curing agent tank 33, a curing agent pump 34, and a dozer 35.

[0021] The main agent pump 32 pumps the main agent in the main agent tank 31 to the dozer 35. The main agent pump 32 and the dozer 35 are connected by a pipe 36. The curing agent pump 34 pumps the curing agent in the curing agent tank 33 to the dozer 35. The curing agent pump 34 and the dozer 35 are connected by a pipe 37. The adhesive pipe of the coating device 20 is connected to the dozer 35. The main agent pipe 21 connects the dozer 35 and the coating device 20 and supplies the main agent to the coating device 20. The curing agent pipe 22 connects the dozer 35 and the coating device 20 and supplies the curing agent to the coating device 20.

[0022] Thus, in the coating process, the conductive adhesive 6 is intermittently applied to the conduction part 11 of the active battery. The active battery is a battery after activation, which has a voltage and is a charged battery. The power storage module 2 described in this explanation is an active battery. Intermittent coating prevents the active battery and the coating device 20 from being electrically connected through the conductive adhesive 6.

[0023] As shown in Figure 5, in the manufacturing method of the comparative example, conductive adhesive 6 is continuously dispensed from the coating device 20. In this comparative example, during the coating process, the conductive adhesive 6 present between the coating device 20 and the active battery drips down, connecting the coating device 20 and the active battery, and thus electrically connecting the coating device 20 and the active battery via the conductive adhesive 6. Coating in a state where the coating device 20 and the active battery are connected by the conductive adhesive 6 is called contact coating. In contact coating, a closed circuit 100 is formed, consisting of the active battery, coating device 20, ground wire, and active battery. When a closed circuit 100 is formed, a short circuit occurs in the battery.

[0024] In contrast, according to the coating process of the embodiment, by intermittently dispensing the conductive adhesive 6 onto the conductive portion 11, it is possible to coat the conductive adhesive 6 while protecting the energy storage module 2, which is a live battery, without forming a closed circuit 100 as in the comparative example.

[0025] In the bipolar battery 1, energy storage modules 2 and metal plate-shaped components are stacked, and the layers are electrically connected by a conductive adhesive 6. In the stacked structure formed by the stacking of energy storage modules 2 and metal plate-shaped components, the layers are constrained by the adhesive force of the conductive adhesive 6. Therefore, the process cannot proceed to the next step until the conductive adhesive 6 has hardened.

[0026] Therefore, the coating process includes a heating process in which the main component and hardener are heated before mixing, as well as the energy storage module 2. In the heating process, the main component pipe 21 and hardener pipe 22, which are adhesive pipes of the coating device 20, are heated, and the energy storage module 2, which is a live battery, is heated by a heater 40. The main component pipe 21 has a built-in heater. The main component is heated by the heater built into the main component pipe 21. The hardener pipe 22 has a built-in heater. The hardener is heated by the heater built into the hardener pipe 22. Then, in the coating process, the conductive adhesive 6, which is a mixture of the heated main component and hardener, is intermittently discharged from the coating device 20, and the conductive adhesive 6 is applied to the conductive part 11 of the heated energy storage module 2. Heating in the live step promotes the curing of the adhesive after mixing the two components, and the cycle time can be shortened.

[0027] The lamination process involves stacking energy storage modules 2, each with a conductive adhesive 6 applied to the conductive portion 11. The lamination process includes joining the energy storage modules 2 and the cooler 4 with the conductive adhesive 6, electrically connecting them via the conductive adhesive 6, and stacking the energy storage modules 2 and the cooler 4 via the conductive adhesive 6. The lamination process forms a laminate constrained by the adhesive force of the conductive adhesive 6.

[0028] As described above, according to the embodiment, since the conductive adhesive 6 is dispensed intermittently from the coating device 20, a closed circuit 100 is not formed via the equipment 30 and the ground wire, the conductive adhesive 6 can be applied to the active battery, and a short circuit of the battery can be prevented.

[0029] Furthermore, heating the conductive adhesive 6 and the energy storage module 2, which is the workpiece to be coated, can accelerate the curing of the adhesive after mixing the two components. This shortens the cycle time. [Explanation of Symbols]

[0030] 1. Bipolar battery 2 Energy storage modules 3 cases 4. Cooler (plate-shaped component) 5. Current collector plate (plate-shaped part) 6. Conductive adhesive 7 Lower Case 11 Conductive section 12 Non-conductive parts 20 Coating device 30 Equipment 40 Heater

Claims

1. A method for manufacturing a bipolar battery in which multiple energy storage modules are stacked, The process includes a coating step of applying a conductive adhesive to an activated and charged energy storage module using a coating device, The coating step includes a step of applying the conductive adhesive to the conductive portion of the energy storage module, by intermittently discharging the conductive adhesive from the coating device so that the coating device and the energy storage module are not connected by the conductive adhesive. A method for manufacturing a bipolar battery, characterized by the following features.

2. The conductive adhesive is a two-component mixed adhesive that hardens by mixing a main component containing a filler and epoxy resin with an amine-based curing agent. The aforementioned coating step is A step of heating the main component and the curing agent before mixing, and heating the energy storage module, The process includes the steps of intermittently discharging the conductive adhesive, which is a mixture of the heated main component and the curing agent, from the coating device, and applying the conductive adhesive to the conductive portion of the heated energy storage module. A method for manufacturing a bipolar battery according to feature 1.

3. The process includes joining the energy storage module, to which the conductive adhesive has been applied to the conductive portion, and the plate-shaped component using the conductive adhesive, and electrically connecting them via the conductive adhesive, as well as a lamination step of stacking the energy storage module and the plate-shaped component via the conductive adhesive. A method for manufacturing a bipolar battery according to feature 2.

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