Manufacturing method of power storage device

Abstract

To provide a manufacturing method of a power storage device capable of reducing compression load.SOLUTION: A disclosed manufacturing method of a power storage device is a manufacturing method of a power storage device that includes a plate-shaped battery module and a plate-like cooler. The manufacturing method includes the following steps: forming a bead by applying adhesive in a straight, parallel pattern with multiple nozzles using an application device over the battery module or cooler; and stacking the battery module and the cooler. The application device includes multiple nozzles, each of which includes an adhesive inlet hole and an adhesive outlet hole, in which the inner diameter of the inlet hole is smaller than the inner diameter of the outlet hole, the inner diameter of the outlet hole is the same as the diameter of the bead, and the nozzle length is at least 50 mm.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing an electricity storage device. [Background technology]

[0002] Large bipolar batteries used in vehicles and the like include a battery module, a cooler, a current collector plate, and a current-carrying plate, and these components are stacked together by applying an adhesive.

[0003] Furthermore, Patent Document 1 discloses a method for discharging liquid substances such as adhesives and electronic materials from a plurality of flow paths at a uniform flow rate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-118779 Summary of the Invention [Problem to be solved by the invention]

[0005] A number of different adhesives are used to stack the large bipolar batteries described above, and since each adhesive has a high viscosity, a high compressive load is generated after application.

[0006] To reduce the compression load, it is preferable to apply the adhesive in multiple thin beads. However, since it is necessary to prevent adjacent beads from coming into contact during compression, a nozzle that can apply the adhesive with precision is required.

[0007] When the dispensing method disclosed in Patent Document 1 is applied to a highly viscous adhesive, the dispensed adhesive merges and becomes one, resulting in a thicker bead, which creates the problem of a higher compressive load. Furthermore, the high viscosity of the adhesive increases the internal pressure of the nozzle, requiring a more robust applicator.

[0008] The present disclosure has been made to solve such problems, and has an object to provide a method for manufacturing an electricity storage device that can reduce the compressive load. [Means for solving the problem]

[0009] A method for manufacturing an electric storage device according to the present disclosure is a method for manufacturing an electric storage device including plate-shaped battery modules and plate-shaped coolers, and includes the steps of applying adhesive linearly and parallel to the battery modules or the coolers using an applicator equipped with multiple nozzles to form beads, and stacking the battery modules and the coolers, wherein each of the multiple nozzles of the applicator has an inlet hole and an outlet hole for the adhesive, the inner diameter of the inlet hole being smaller than the inner diameter of the outlet hole and the inner diameter of the outlet hole being the same as the diameter of the bead, and the length of the nozzle is 50 mm or more. This makes it possible to provide a method for manufacturing an electric storage device that can reduce compressive load.

[0010] The inner diameter of the inlet hole may be 40% of the inner diameter of the outlet hole, thereby providing a method for manufacturing an electricity storage device that can reduce the compressive load.

[0011] The adhesive may be at least two types, a thermally conductive material and a conductive adhesive, and both the thermally conductive material and the conductive adhesive may contain a metal filler. This makes it possible to provide a method for manufacturing an electricity storage device that can reduce the compressive load.

[0012] The thermally conductive material and the electrically conductive adhesive may each have a viscosity of 400 Pa·s. This makes it possible to provide a method for manufacturing an electricity storage device that can reduce the compressive load. [Effects of the Invention]

[0013] The present disclosure provides a method for manufacturing an electricity storage device that can reduce compressive load. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram illustrating a power storage device according to the present disclosure. [Figure 2] FIG. 1 is a diagram illustrating a coating device according to the present disclosure. [Figure 3] FIG. 10 is a diagram showing calculation results of coating flow rate variations. [Figure 4] FIG. 2 is a diagram illustrating an analysis model of a coating device. [Figure 5] FIG. 10 is a diagram showing calculation results of coating flow rate variations. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Fig. 1(a) is a cross-sectional view of a power storage device 1 according to the present embodiment.

[0016] The energy storage device 1 has a structure in which a plurality of battery modules 10 and a plurality of coolers 20 are stacked in a lower case 70. The battery modules 10 and the coolers 20 are each flat plate-shaped. A current collector plate 30 is provided in the lowest layer of the stacked structure.

[0017] The power storage device 1 according to the present disclosure is preferably a non-aqueous battery that contains, as the electrolyte impregnated in the separator, a liquid electrolyte (electrolytic solution) that contains a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent.

[0018] Beads are formed between each layer of the laminated structure by applying adhesive. Specifically, thermally conductive material 40 and conductive adhesive 50 are applied alternately between the battery module 10 and the cooler 20, and structural adhesive 60 and conductive adhesive 50 are applied alternately between the bottom current collector plate 30 and the cooler 20.

[0019] The thermally conductive material 40 is a material that preferably combines elasticity and thermal conductivity, and is made of a gel material such as grease. Silver paste or the like is preferably used as the conductive adhesive 50. It is preferable to use a material for the structural adhesive 60 that does not lose its adhesive properties much under load.

[0020] FIG. 1(b) is a top view of the applied adhesive. The left side of FIG. 1(b) shows the state after the adhesive application process, and the right side of FIG. 1(b) shows the state after the stacking and compression process. The adhesive is applied in a straight and parallel pattern on the battery module 10 or the cooler 20. Note that, because the adhesive spreads upon stacking and compression, it is preferable to apply the adhesive so that the beads do not come into contact with each other after compression. This makes it possible to reduce the compression load. The diameter of the beads when applied is preferably about 2.5 mm.

[0021] The application of the thermally conductive material 40, the electrically conductive adhesive 50, and the structural adhesive 60 will be described with reference to FIG. 2. FIG. 2 is a cross-sectional view of an application device 100 for applying the thermally conductive material 40, the electrically conductive adhesive 50, and the structural adhesive 60. The application device 100 includes an inlet 101 and a plurality of nozzles 102. The application device 100 according to the present disclosure has the configuration described below, and is therefore capable of simultaneously applying a large number of (preferably 20 or more) bottles of multiple types of adhesive.

[0022] The thermally conductive material 40, the conductive adhesive 50, and the structural adhesive 60 each contain a metal filler and have a high viscosity of approximately 400 Pa·s. Therefore, increasing the nozzle internal pressure to reduce variations in the application flow rate requires a more robust application device. The generally allowable nozzle internal pressure is 13 MPa or less. The application device 100 according to the present disclosure, having the configuration described below, is capable of reducing variations in the application flow rate while satisfying the allowable nozzle internal pressure.

[0023] The nozzle 102 has an inlet hole and an outlet hole with different diameters. In the coating device 100 according to the present disclosure, the inner diameter D of the outlet hole is approximately the same as the diameter of the bead to be coated, and the inner diameter d of the inlet hole is preferably smaller than the inner diameter D of the outlet hole, and particularly preferably about 40% of that. Furthermore, the length L of the nozzle 102 is preferably 50 mm or more.

[0024] In this way, by using the coating device 100 in which the inner diameter d of the inlet hole, the inner diameter D of the outlet hole, and the length L of the nozzle 102 are adjusted, the flow rate can be made uniform even for adhesives with high viscosities of about 400 Pa·s, thereby making it possible to reduce variations in the coating flow rate. [Example]

[0025] The present disclosure will be described below using examples, but is not limited thereto.

[0026] In order to verify the effect of the shape of the nozzle 102 of the coating apparatus 100 according to the present disclosure, the variation in the coating flow rate was calculated by CAE (Computer Aided Engineering) analysis.

[0027] Example 1 We investigated the dimensions of the inner diameter of the nozzle 102 of the coating device 100. For the coating device 100 shown in Fig. 2, we created analytical models for the inner diameter d of the inlet hole and the inner diameter D of the outlet hole of the nozzle 102 at two levels shown in Table 1, and calculated the variation in the coating flow rate when a liquid with a viscosity of 400 Pa s was flowed. [Table 1]

[0028] The results of the CAE analysis are shown in Figure 3. Figure 3 compares the coating flow rate error, which is the variation in the coating flow rate, between Level 1 and Level 2. It was found that by narrowing the inner diameter d of the inlet hole to 40% of the inner diameter D of the outlet hole, the variation in the coating flow rate was improved by 55%.

[0029] <Example 2> The length of the nozzle 102 of the coating apparatus 100 was examined. Figures 4(a) and (b) show an analytical model of the coating apparatus 100 used in the CAE analysis. The coating apparatus 100 has a total of m nozzles, 102-1, 102-2, ..., 102-m. In this example, for a coating apparatus having 24 nozzles (m = 24), models were created with three levels of length L for the nozzles 102-1 to 102-m: 10 mm, 50 mm, and 100 mm, and the variation in coating flow rate was calculated. The inner diameter d of the inlet hole and the inner diameter D of the outlet hole of the nozzle 102 were fixed at d = 1.0 mm and D = 2.5 mm, based on the results of Example 1.

[0030] Figure 5 is a graph plotting the coating flow rate error, which is the variation in the coating flow rate, on the vertical axis and the nozzle length L on the horizontal axis. When the variation tolerance was set at 8% as the specification target, the analytical model with a nozzle length of 10 mm exceeded the specification target. On the other hand, the analytical models with nozzle lengths of 50 mm and 100 mm suppressed the variation in the coating flow rate, and results were obtained that favorably met the specification target.

[0031] The electricity storage device 1 according to the present disclosure is manufactured using a coating device 100 in which the inner diameter d of the inlet hole, the inner diameter D of the outlet hole, and the length L of the nozzle 102 are specified, thereby achieving both the allowable internal pressure of the facility (13 MPa or less) and flow rate variation (±8%). Therefore, it is possible to provide a manufacturing method for an electricity storage device that can reduce the compressive load.

[0032] The present disclosure is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0033] 1. Energy storage device 10 Battery Module 20 Cooler 30 Current collector plate 40 Thermal Conductive Materials 50 Conductive adhesive 60 Structural Adhesives 70 Lower case 100 Coating device 101 Inlet 102 nozzle

Claims

1. A method for manufacturing an electricity storage device including a plate-shaped battery module and a plate-shaped cooler, applying adhesive in linear and parallel directions on the battery module or the cooler using an application device equipped with multiple nozzles to form a bead; and stacking the battery module and the cooler, The plurality of nozzles of the application device each have an inlet hole and an outlet hole for the adhesive; an inner diameter of the inlet hole is smaller than an inner diameter of the outlet hole; The inner diameter of the outlet hole is the same as the diameter of the bead; The length of the nozzle is 50 mm or more. A method for manufacturing an electricity storage device.

2. The inner diameter of the inlet hole is 40% of the inner diameter of the outlet hole. A method for manufacturing the electricity storage device according to claim 1 .

3. The adhesive is at least two types of adhesive, a thermally conductive material and an electrically conductive adhesive, The thermally conductive material and the electrically conductive adhesive both contain a metal filler. A method for manufacturing the electricity storage device according to claim 1 .

4. The viscosity of the thermally conductive material and the conductive adhesive is 400 Pa·s. The method for manufacturing the electricity storage device according to claim 3 .

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