Method of manufacturing a battery pack

Abstract

Disclosed is a manufacturing method for a battery pack, which eliminates contact failure between a part and a thermally conductive material without adding a manufacturing step. A manufacturing method for a battery pack, which has a battery module in which a plurality of battery cells are stacked, includes: a coating step of coating a thermally conductive material on a lower case in such a manner that a coating track of the thermally conductive material has a back pressure pattern shape; and a setting step of setting the battery module inside the lower case in such a manner that the thermally conductive material coated in the back pressure pattern shape is pressed.

Description

Technical Field

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

[0002] Patent document 1 discloses a method for manufacturing a battery pack, in which the parts are inspected for ripples each time, and in order to match the ripples on the side of the parts, a thermally conductive material different from the usual process is applied and cured to ensure surface accuracy, and then the thermally conductive material of the usual process is applied.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2017-111872 Summary of the Invention

[0004] The structure described in Patent Document 1 can eliminate poor contact between the part and the heat-conducting material caused by the shape of the part. However, in the structure described in Patent Document 1, as the number of parts increases, it is necessary to implement countermeasures against ripples each time, thus increasing the number of manufacturing steps.

[0005] The present invention was made in view of the above circumstances, and its object is to provide a method for manufacturing a battery pack that eliminates poor contact between parts and thermally conductive materials without additional manufacturing processes.

[0006] This invention relates to a method for manufacturing a battery pack, the battery pack comprising a battery module formed by stacking multiple battery cells, the method comprising: a coating step, wherein the thermally conductive material is coated onto a lower housing in such a way that the coating trajectory of the thermally conductive material forms a back-pressure pattern shape; and a setting step, wherein the battery module is set inside the lower housing by pressing the thermally conductive material coated in the back-pressure pattern shape.

[0007] Invention Effects

[0008] In this invention, poor contact between the parts and the thermally conductive material can be eliminated without additional manufacturing processes. Attached Figure Description

[0009] Figure 1 This is a diagram illustrating the coating process included in the battery pack manufacturing method of the embodiment.

[0010] Figure 2 It is a diagram used to illustrate the flow of air when a thermally conductive material is pressed.

[0011] Figure 3 It is a diagram showing the shape of the thermally conductive material applied through the coating process.

[0012] Figure 4 It is a diagram showing the shape of a thermally conductive material that has been compressed and stretched through a setting process. Detailed Implementation

[0013] The manufacturing method of the battery pack according to the embodiments of the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below.

[0014] The method for manufacturing the battery pack in this embodiment is a method for manufacturing a battery pack mounted on an electric vehicle. When mounted on an electric vehicle, the battery pack supplies power to the vehicle's drive motor. The battery pack includes multiple battery modules, a housing that houses the multiple battery modules, and a cooler for cooling the battery modules.

[0015] A battery module is a battery pack composed of multiple stacked battery cells. A housing houses the battery modules. Multiple battery modules are housed inside the housing. The housing has an upper cover and a lower cover. The upper cover and lower cover are fastened together by fastening components. The lower cover has a bottom and side walls. Multiple modules are located inside the housing, at the bottom of the lower cover. A cooler is used to cool the battery cells. The cooler is located outside the housing. It is positioned below the housing and mounted on the bottom of the lower cover. The cooler cools the battery cells from outside the housing via the bottom of the lower cover.

[0016] In the battery pack, thermally conductive material is applied to both sides of the bottom of the lower housing. This thermally conductive material includes material disposed inside the lower housing between the inner surface of the bottom of the lower housing and the lower surface of the battery module, and material disposed outside the lower housing between the outer surface of the bottom of the lower housing and the upper surface of the cooler. The thermally conductive material is included in the heat transfer path from the cooler to the battery cell. During battery pack manufacturing, the thermally conductive material is applied to the bottom of the lower housing; the material applied to the inner surface of the bottom of the lower housing is crushed by the battery module, and the material applied to the outer surface of the bottom of the lower housing is crushed by the cooler.

[0017] As battery capacity increases, the heat generated by the battery pack also increases, so improving cooling performance is desirable as a thermal countermeasure. Therefore, for the thermally conductive material coated between various components, it is necessary to increase the contact area between the components and the thermally conductive material. However, during battery pack manufacturing, the thermally conductive material is crushed by the components. Therefore, even when the thermally conductive material is coated to meet target thickness and area during the coating stage, depending on the shape of the component, situations may occur where the component does not contact the thermally conductive material. Therefore, in this embodiment, the thermally conductive material is configured such that by setting the coating path of the thermally conductive material to a back-pressure pattern shape, even if air remains during crushing, air entrapment can be eliminated, and the thermally conductive material is crushed to a thickness and area independent of the component shape.

[0018] The battery pack manufacturing method in the embodiment includes: a coating process, in which a thermally conductive material is coated onto a housing that houses the energy storage module; and a setting process, in which the battery module is set inside the housing by crushing the thermally conductive material.

[0019] like Figure 1 As shown, the coating process involves applying the thermally conductive material 2 to the bottom 1a of the lower housing 1. The coating process includes applying the thermally conductive material 2 to the inner surface of the bottom 1a of the lower housing 1 in a back-pressure pattern shape. In the coating process, the coating pattern of the thermally conductive material 2 is a repeating serrated pattern. The angle of the serrated path is preferably 10 to 45 degrees.

[0020] The setting process involves placing the battery module on the bottom 1a of the lower housing 1 by pressing and coating the thermally conductive material 2 into a back-pressure pattern. The setting process includes a process in which the thermally conductive material 2 is crushed by the battery module by clamping it between the lower surface of the battery module and the inner surface of the bottom 1a.

[0021] If air is entangled during pressing, it will result in uncontacted areas between the part and the thermally conductive material 2, leading to a decrease in quality. In this embodiment, the coating path of the thermally conductive material 2 is set to a back-pressure pattern shape, such as... Figure 2 As shown, this creates an airflow when pressed, eliminating air entrapment even if residual air remains after crushing.

[0022] like Figure 3 As shown, through the coating process, the thermally conductive material 2 is coated into a back-pressure pattern shape. If the battery module is installed from this state through the setting process, then as shown... Figure 4 As shown, the thermally conductive material 2 is compressed and diffused. The battery module is a stack of multiple battery cells, and therefore the positions of the battery cells sometimes deviate in the height direction. In this case, ripples are generated on the lower surface of the battery module. Furthermore, the bottom 1a of the lower housing 1 sometimes becomes distorted. In the coating process, by setting the coating path of the thermally conductive material 2 to a back-pressure pattern shape, even if air remains during compression, air entrapment can be eliminated, thereby ensuring a stable thickness and area of ​​the thermally conductive material 2 independent of the part shape.

[0023] As explained above, according to the embodiment, air entrapment can be suppressed during crushing. Therefore, poor contact of the thermally conductive material 2 caused by the shape of the part can be eliminated without additional manufacturing processes.

[0024] Furthermore, it can correspond to the shape of the part regardless of the coating position of the thermally conductive material 2. Therefore, the contact area with the thermally conductive material 2 can be ensured without additional manufacturing processes or manufacturing costs.

[0025] In addition, during the coating process, the angle of the sawtooth trajectory is not limited to 10-45 degrees, but can be an appropriate angle.

[0026] Furthermore, the battery pack manufacturing method may include a coating process of applying thermally conductive material 2 to the outer surface of the bottom 1a of the lower housing 1 and an installation process of mounting a cooler to the lower housing 1. The coating process applies the thermally conductive material 2 to the outer surface of the bottom 1a of the lower housing 1 in a back-press pattern. The installation process involves pressing the thermally conductive material 2, which is coated in a back-press pattern, onto the bottom 1a of the lower housing 1. The installation process includes pressing the thermally conductive material 2 between the upper surface of the cooler and the outer surface of the bottom 1a by crushing the thermally conductive material 2 with the cooler.

[0027] Symbol Explanation

[0028] 1-Lower shell, 1a-Bottom, 2-Heat-conducting material.

Claims

1. A method for manufacturing a battery pack, the battery pack comprising a battery module formed by stacking multiple battery cells, the method for manufacturing the battery pack characterized in that it includes: In the coating process, the thermally conductive material is coated onto the lower housing in such a way that the coating trajectory of the thermally conductive material becomes a back pressure pattern shape; and The battery module is installed inside the lower housing by pressing and coating the thermally conductive material into the back-pressure pattern shape.

2. The method for manufacturing a battery pack according to claim 1, characterized in that, The coating process includes the process of coating the thermally conductive material onto the inner surface of the bottom of the lower housing. The setting process includes the step of crushing the thermally conductive material by means of the battery module, such that the thermally conductive material is clamped between the lower surface of the battery module and the inner surface of the bottom.

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