JP7147630B2 - Method for manufacturing battery stack - Google Patents

Description

The present invention relates to a method for manufacturing a battery stack. More specifically, it relates to a method of manufacturing a battery stack by housing a plurality of secondary batteries in a case.

Secondary batteries such as lithium-ion secondary batteries, for example, when used as a power source for electronic devices or as a drive power source for electric vehicles, are combined in multiple battery stacks in order to obtain the required output and capacity. used. Some of such battery stacks are integrated by housing a plurality of secondary batteries in a case.

For example, Patent Literature 1 describes a method of manufacturing a battery stack in which a plurality of secondary batteries are arranged in the thickness direction and housed in a case. In addition, in Patent Document 1, when the secondary batteries are accommodated in the case, a plurality of secondary batteries arranged in the thickness direction are lifted while being sandwiched from the outside in the arrangement direction, and then lowered into the case. are accommodated.

JP 2018-49803 A

By the way, when a secondary battery group in which a plurality of secondary batteries are arranged is lifted, gravity acts. For this reason, in a secondary battery group lifted while being sandwiched from the outside in the arrangement direction, the secondary batteries forming the secondary battery group are displaced in the direction of gravity. This deviation of the secondary battery in the direction of gravity appears in the whole secondary battery group as a deformation that is bent in the direction of gravity.

In addition, when a secondary battery group in a bent state is accommodated in a case, there is a problem that, for example, interference occurs between the case and the secondary battery group. If such interference occurs, there is a possibility that the secondary battery group cannot be properly accommodated in the case.

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-described problems of the prior art. That is, an object of the present invention is to provide a method for manufacturing a battery stack that can properly house a plurality of secondary batteries in a case to manufacture a battery stack.

A method for manufacturing a battery stack according to the present invention, which has been made for the purpose of solving this problem, is a method for manufacturing a battery stack in which a secondary battery group formed by arranging a plurality of secondary batteries is housed in a case through an opening of the case. The secondary battery group is arranged side by side so that all of the secondary batteries are in contact with the reference surface on the first surface , and each of the two ends in the arrangement direction is arranged upward from the reference surface. An arrangement step of arranging an end plate provided with an extending space, and a group of secondary batteries arranged side by side with respect to a reference plane is pressed from below the reference plane into the spaces of the end plates located at both ends in the arrangement direction. A pressing step in which the secondary battery group in the pressed state is pressed from the outside in the arrangement direction by the pressing portion while being inserted, and the secondary battery group in the pressed state is placed on the second surface side opposite to the first surface of the secondary battery. Then, a step of entering the case from the opening is performed, and after the pressed secondary battery group is housed in the case, the pressing by the pressing portion is released and the pressing portion is removed from the space. A method for manufacturing a battery stack characterized by:

In the battery stack manufacturing method according to the present invention, each secondary battery in the secondary battery group can be accommodated in a state in which the first surface is supported by the reference surface. Further, each secondary battery in the secondary battery group is accommodated in the case from the second surface side opposite to the first surface. Therefore, the secondary battery group can be housed in the case in a state in which the secondary batteries are properly aligned in the arrangement direction. Thereby, a battery stack can be manufactured by properly housing a plurality of secondary batteries in the case.

According to the present invention, there is provided a battery stack manufacturing method capable of manufacturing a battery stack by appropriately housing a plurality of secondary batteries in a case.

1 is a perspective view of a battery stack according to an embodiment; FIG. 1 is a perspective view of a secondary battery; FIG. FIG. 4 is a perspective view of an end plate; FIG. 4 is a diagram showing a state in which a secondary battery group is placed on a reference platform; It is a perspective view of a pressing claw. FIG. 3 is a plan view showing the positional relationship between a secondary battery group, end plates, and pressing claws; It is a figure which shows the state which inserted the press claw into the groove|channel of an end plate. FIG. 4 is a diagram showing a secondary battery group in a pressed state pressed from the outside in the arrangement direction; FIG. 3 is a diagram showing a secondary battery group and a case before assembly; FIG. 4 is a diagram showing a state in which a secondary battery group is inserted into a case; FIG. 4 is a diagram showing the secondary battery group and the case after assembly;

BEST MODE FOR CARRYING OUT THE INVENTION The best mode embodying the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a battery stack 1 manufactured in this embodiment. The battery stack 1 is configured by housing a secondary battery group 50 including a plurality of secondary batteries 10 in a case 20 . FIG. 1 shows the X direction, Y direction, and Z direction as directions for the battery stack 1 . As shown in FIG. 1, the secondary battery 10 in the battery stack 1 is accommodated in the case 20 with the thickness direction in the X direction, the width direction in the Y direction, and the height direction in the Z direction. Also, the secondary batteries 10 in the secondary battery group 50 are arranged side by side in the X direction, that is, in the thickness direction. Therefore, the arrangement direction of the plurality of secondary batteries 10 in the secondary battery group 50 is the X direction.

FIG. 2 is a perspective view of the secondary battery 10. FIG. As shown in FIG. 2, the secondary battery 10 has an outer surface formed by a battery case 19 and has a cuboid (rectangular) outer shape. The battery case 19 has a first surface 11 which is an outer surface located at one end in the height direction, and a second surface 12 located on the opposite side of the first surface 11 . In addition, of the outer surfaces of the battery case 19, the wide surface 13, which is the end surface in the thickness direction, has the largest area.

The secondary battery 10 also has a positive electrode portion 15 and a negative electrode portion 16 both provided on the first surface 11 . Both the positive electrode portion 15 and the negative electrode portion 16 are provided so as to protrude from the first surface 11 . The positive electrode portion 15 and the negative electrode portion 16 are connected to the positive electrode plate and the negative electrode plate inside the battery case 19, respectively. Thereby, the secondary battery 10 can be charged and discharged by the positive electrode portion 15 and the negative electrode portion 16 . The secondary battery 10 is, for example, a lithium ion secondary battery.

As shown in FIG. 1, the secondary batteries 10 in the battery stack 1 are accommodated in the case 20 in a state in which the adjacent secondary batteries 10 face each other with their large surfaces 13 facing each other. An insulating spacer or the like may be interposed between the wide surfaces 13 of the adjacent secondary batteries 10 .

As shown in FIG. 1, end plates 30 are provided on both sides of the secondary battery group 50 in the X direction. That is, the secondary battery group 50 is accommodated in the case 20 while being sandwiched between the end plates 30 from both sides in the arrangement direction.

3 is a perspective view of the end plate 30. FIG. FIG. 3 shows a first surface 31 and a second surface 32 on the opposite side of the first surface 31 for the outer surface of the end plate 30 . As shown in FIG. 3, the second surface 32 is provided with four grooves 35 extending in parallel. As a result, a space recessed from the second surface 32 is formed at the position of the groove 35 . Then, as shown in FIG. 1, the end plate 30 is arranged such that the second surface 32 on which the grooves 35 are formed faces outward in the X direction, and the extending direction of the grooves 35 is aligned with the Z direction. It is housed inside the case 20 .

The case 20 has an opening 21 formed in a surface positioned at one end in the Z direction. Secondary battery group 50 and end plate 30 are inserted into case 20 through opening 21 . In addition, the first surface 11 of each of the plurality of secondary batteries 10 in the secondary battery group 50 accommodated in the case 20 is exposed through the opening 21 . As a result, the positive electrode portions 15 and the negative electrode portions 16 of the plurality of secondary batteries 10 in the secondary battery group 50 protrude from the openings 21 .

Next, a method for manufacturing the battery stack 1 will be described. The battery stack 1 of this embodiment is manufactured by the following steps.
1. Placement step 2. pressing step3. Containment process

First, "1. Placement process" will be described. FIG. 4 is a diagram for explaining the placement process. As shown in FIG. 4, a reference table 100 is used in the placement process. In FIG. 4, the vertical direction is the direction of gravity, and gravity acts downward. Then, in the placement step, the secondary batteries 10 are placed on the reference table 100 to form the secondary battery group 50 .

That is, as shown in FIG. 4 , the secondary battery group 50 is placed on the reference surface 101 that is the upper surface of the reference table 100 in an arrangement that is accommodated in the case 20 . Specifically, a plurality of secondary batteries 10 are arranged in the thickness direction by facing each other with their wide surfaces 13 . At this time, the first surface 11 of the secondary battery 10 faces downward and the second surface 12 faces upward. That is, the first surface 11 of the secondary battery 10 is brought into contact with the reference surface 101 of the reference table 100 .

Note that the positive electrode portion 15 and the negative electrode portion 16 of the secondary battery 10 are omitted from FIG. 4 onward. However, as described above, the positive electrode portion 15 and the negative electrode portion 16 are protruded from the first surface 11 of the secondary battery 10 . For this reason, a relief portion is formed on the reference surface 101 of the reference table 100 so that the positive electrode portion 15 and the negative electrode portion 16 of the placed secondary battery 10 do not interfere with each other. Further, the secondary battery group 50 shown in FIG. 4 is a cross-sectional view at the AA position shown in FIG.

In the arrangement step, end plates 30 are arranged at both ends of the secondary battery group 50 in the arrangement direction. At this time, the grooves 35 of the end plates 30 are directed outward in the arrangement direction, and the extending direction of the grooves 35 is aligned with the vertical direction. That is, the end plate 30 is also placed on the reference surface 101 of the reference table 100 in the same state as the secondary battery group 50 when it is accommodated in the case 20 . That is, in the arranging step, the containing body 60 to be accommodated in the case 20 and composed of the secondary battery group 50 and the end plate 30 is arranged on the reference surface 101 .

Two pressing claws 120 are arranged below the reference table 100, as shown in FIG. FIG. 5 shows a perspective view of the pressing claw 120. As shown in FIG. As shown in FIG. 5, the pressing claw 120 has a claw portion 121 and a base portion 122 . The claw portion 121 is provided so as to protrude from the base portion 122 . Four claw portions 121 are provided on the base portion 122 . The claw portion 121 is provided in a shape and arrangement corresponding to the groove 35 of the end plate 30 .

6 is a plan view showing a state in which the claw portion 121 of the pressing claw 120 is aligned with the groove 35 of the end plate 30. FIG. As shown in FIG. 6, the four claw portions 121 are arranged and sized so as to fit in the grooves 35 of the end plate 30, respectively. As shown in FIG. 4, each of the two pressing claws 120 is provided so that the claw portion 121 is positioned below the groove 35 of the end plate 30 provided to sandwich the secondary battery group 50. . A through hole 102 is formed in the base 100 at a position corresponding to the upper side of the claw portion 121 . Therefore, the claw portion 121 of the pressing claw 120 can pass through the through hole 102 of the reference table 100 and protrude above the reference plane 101 .

Next, "2. Pressing step" will be described. In the pressing step, the secondary battery group 50 is pressed from the outside in the arrangement direction to be in a pressed state. That is, as shown in FIG. 7, first, the pressing claw 120 is moved upward so that the claw portion 121 projects upward from the reference surface 101 . That is, the claw portion 121 is inserted into the groove 35 of the end plate 30 from below.

Then, as shown in FIG. 8, the two pressing claws 120 are moved toward each other. As a result, the two pressing claws 120 press the container 60 in the arrangement direction of the secondary battery group 50 . That is, the secondary battery group 50 is pressed from the outside in the arrangement direction to be in a pressed state. Since the secondary battery group 50 in the pressed state is pressed in the arrangement direction, the length in the arrangement direction is shorter than that in the free state before being put into the pressed state. FIG. 8 shows the length X2, which is the outer dimension of the containers 60 in the arrangement direction. The length X2 in the pressed state is shorter than the length X1 in the non-pressed state shown in FIG.

When the secondary battery group 50 is put in the pressed state, next, "3. accommodation process" is performed. In the accommodation step, the secondary battery group 50 is accommodated by being inserted into the case 20 . That is, the case 20 is set above the secondary battery group 50 as shown in FIG. In the housing step, the case 20 has the opening 21 facing downward in order to house the secondary battery group 50 in the internal space 25 of the case 20 . That is, the opening 21 of the case 20 faces the secondary battery group 50 side. 9 shows the length Y (inner dimension) of the opening 21 of the case 20 in the direction in which the secondary battery group 50 is arranged. The length Y of the opening 21 of the case 20 is longer than the length X2 of the container 60 in the pressed state.

Then, as shown in FIG. 10, the case 20 is lowered and the container 60 is inserted into the case 20 . As a result, the secondary battery group 50 enters the case 20 through the opening 21 from the second surface 12 side of the secondary battery 10 . The container 60 in FIG. 10 is still in a pressed state in which it is pressed from the outside in the arrangement direction. Therefore, the secondary battery group 50 can enter the case 20 through the opening 21 while suppressing interference between the case 20 and the secondary battery group 50 or the end plate 30 .

Further, even if the secondary battery group 50 entering the case 20 interferes with the case 20 , the secondary batteries 10 in the secondary battery group 50 are prevented from moving in the direction of gravity. When the secondary battery group 50 entering the case 20 interferes with the case 20 , a downward force is applied to the secondary battery 10 in the direction of gravity. However, since the first surface 11 of the secondary battery 10 is in contact with the reference surface 101, the downward movement of the secondary battery 10 in the direction of gravity is restricted. Therefore, the secondary battery group 50 can be accommodated in the case 20 while being aligned with the reference plane 101 . That is, it is possible to configure the battery stack 1 in which the secondary batteries 10 in the case 20 are arranged straight in the arrangement direction.

Thereafter, as shown in FIG. 11, the pressing by the pressing claw 120 is released and the pressing claw 120 is lowered. As a result, the pressed state of the secondary battery group 50 is released. The secondary battery group 50 released from the pressed state by the pressing claw 120 has a longer length in the arrangement direction than in the pressed state. That is, the length X3 of the container 60 shown in FIG. 11 is longer than the length X2 in the pressed state.

However, the length X3 is shorter than the length X1 (FIG. 7, etc.) in the free state. That is, in the state shown in FIG. 11, each secondary battery 10 constituting the secondary battery group 50 is applied with an appropriate pressing force in the thickness direction. As a result, the battery stack 1 can be configured while appropriately applying a pressing force in the thickness direction to each secondary battery 10 . Therefore, expansion of the secondary battery 10 in the thickness direction is suppressed.

Note that the thickness of the secondary battery 10, the size of the case 20, and the like have variations. In such a case, by housing a shim or the like for adjusting the variation in the case 20 together with the secondary battery group 50, the pressing force that the secondary battery 10 receives in the thickness direction in the battery stack 1 can be adjusted. can be done.

When performing adjustment using such shims, the lengths of the container 60 and the case 20 are measured in advance before the accommodation process, and the size and number of shims to be accommodated in the case 20 together with the secondary battery group 50 are determined. You just have to decide. That is, before the accommodation process, a length measurement process for measuring the outer dimension of the accommodation bodies 60 and the inner dimension of the case 20 in the arrangement direction may be performed. Then, in the accommodation step, the shims selected so as to adjust the variation may be accommodated in the case 20 together with the accommodation body 60 .

Moreover, in order to make the pressing force applied to the secondary batteries 10 in the battery stack 1 in the thickness direction more appropriate, it is preferable to measure the length of the secondary battery group 50 in a pressed state. That is, for example, in the length measurement process, the pressing claws 120 are used to apply an appropriate pressing force to the container 60 as a predetermined pressing force for the secondary batteries 10 in the battery stack 1, and in that state, the arrangement direction is adjusted. Measure outside dimensions. Further, the inner dimension of the case 20 in the arrangement direction is also measured, and then the above-described pressing process is performed, and further, the housing process of housing the shim and the housing body 60 into the case 20 is performed. As a result, a pressing force equal to the pressing force applied in the length measurement process can be applied to the secondary battery 10 accommodated in the case 20 together with the shim.

As described above in detail, in the manufacturing method of the battery stack 1 according to the present embodiment, the arranging process, the pressing process, and the accommodating process are performed. In the arranging step, the secondary battery group 50 is arranged side by side so that each secondary battery 10 is in contact with the reference surface 101 of the reference table 100 on the first surface 11 . In the pressing step, the secondary battery group 50 arranged on the reference plane 101 is pressed by the pressing claws 120 from the outside in the arrangement direction to be in a pressing state. In the accommodation step, the secondary battery group 50 in the pressed state is entered into the case 20 from the second surface side of each secondary battery 10 through the opening 21 . As a result, each secondary battery 10 in the secondary battery group 50 is housed in the case 20 with the first surface 11 aligned with the reference surface 101 . Therefore, a method for manufacturing a battery stack is realized that can manufacture a battery stack by properly housing a plurality of secondary batteries in a case.

Further, since the first surfaces 11 of the secondary batteries 10 in the secondary battery group 50 are aligned on the same plane, the heights of the positive electrode portions 15 and the negative electrode portions 16 can also be aligned. Therefore, when the positive electrode portion 15 and the negative electrode portion 16 are connected by a bus bar, the connection of the bus bar can be performed appropriately.

It should be noted that the present embodiment is merely an example, and does not limit the present invention in any way. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist of the invention. For example, in the above embodiment, an example in which the present invention is applied to a lithium ion secondary battery has been described. However, the present invention is applicable not only to lithium-ion secondary batteries, but also to any method of manufacturing a battery stack by arranging a plurality of secondary batteries and housing them in a case.

1 Battery Stack 10 Secondary Battery 11 First Surface 12 Second Surface 20 Case 21 Opening 100 Reference Base 101 Reference Surface 120 Pressing Claw

Claims (1)

In a method for manufacturing a battery stack in which a secondary battery group comprising a plurality of secondary batteries arranged side by side is housed in the case through an opening of the case,
The secondary battery group is arranged side by side so that each of the plurality of secondary batteries is in contact with the reference surface on the first surface, and both ends in the arrangement direction extend upward from the reference surface. an arrangement step of arranging an end plate provided with a space ;
The secondary battery groups arranged side by side with respect to the reference plane are inserted into the spaces of the end plates positioned at both ends in the arrangement direction from below the reference plane. A pressing step of pressing from the outside in the arrangement direction to be in a pressed state;
a step of inserting the secondary battery group in the pressed state into the case through the opening from a second surface side opposite to the first surface of the secondary battery ,
After the secondary battery group in the pressed state is accommodated in the case, the pressing by the pressing portion is released and the pressing portion is removed from the space. .

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