JP7006073B2 - Secondary battery - Google Patents

Description

The present disclosure relates to a secondary battery.

In the manufacturing process of a power storage device such as a secondary battery, a lid material is welded to the upper surface of a metal outer case, and an electrolytic solution is injected from a liquid injection port provided in the lid material with the electrode body housed. A liquid injection process is provided.

Regarding the manufacturing process of such a secondary battery, for example, Japanese Patent Application Laid-Open No. 2017-117657 (Patent Document 1) describes a cap until the injection process of injecting an electrolytic solution into the outer case of the battery is performed. The technique of closing the injection port with a magnet and fixing it with a magnet is disclosed.

JP-A-2017-117657

However, depending on the manufacturing process of the secondary battery, the magnet for fixing the cap may be removed, and the cap may come off from the liquid injection port during the period when the magnet is removed. On the other hand, it is possible to close the liquid injection port without a magnet by strengthening the connection between the cap and the liquid injection port, but when the work of removing the cap cannot be easily performed in the liquid injection process. There is.

The present disclosure has been made to solve the above-mentioned problems, and an object thereof is to ensure that the injection port is closed until the injection step and to easily expose the injection port in the injection step. Is to provide a secondary battery capable of.

The secondary battery according to a certain aspect of the present disclosure includes an outer case, an electrode body housed inside the outer case, and a lid provided on the upper part of the outer case so as to close the liquid injection port and the liquid injection port. It is provided with a top surface member provided with a portion. The upper surface member is provided with a recess. The recess is formed so that a liquid injection port is formed on the bottom surface and is movable between a first position where the lid portion closes the liquid injection port and a second position where the lid portion is separated from the liquid injection port. To. The sliding surface of the bottom surface of the recess with the lid is inclined so that the first position is lower than the second position.

In this way, the sliding surface of the bottom surface of the recess with the lid portion is inclined so that the first position is lower than the second position. Therefore, for example, the position of the lid portion is the first position. In this case, the movement of the lid portion to the second position can be suppressed by its own weight. On the other hand, at the time of liquid injection, the liquid injection port can be easily exposed by moving the position of the lid portion to the second position.

According to the present disclosure, it is possible to provide a secondary battery capable of easily exposing the liquid injection port in the liquid injection step while reliably closing the liquid injection port until the liquid injection step.

It is a front view which shows the secondary battery, and is the front view which made a part | cross-sectional view. It is an enlarged view of the broken line frame of FIG. It is a perspective view of the upper surface member when the lid part is a 1st position. It is a figure which shows the sliding surface with the bottom surface of the concave part on the back side of a lid part. It is the figure which looked at the cross-sectional view of the liquid injection part when the lid part is a 2nd position. It is a perspective view of the upper surface member when the lid part is a 2nd position. It is a manufacturing flow diagram which shows the manufacturing process of a secondary battery. It is a front view which shows the upper surface unit assembly process S1. It is a front view which shows the electrode body connection process S2. It is a front view which shows the accommodating process S3. It is a front view which shows the welding process S4. It is a front view which shows the liquid injection process S5. It is a front view which shows the sealing process S6. It is the figure which took the cross-sectional view of the liquid injection part in the case where the lid part in a modification is a 1st position. It is the figure which took the cross-sectional view of the liquid injection part in the case where the lid part in a modification is a 2nd position.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated.

FIG. 1 is a front view showing a secondary battery 1, which is a front view partially viewed in cross section. The secondary battery 1 includes an electrode body 2, a housing case 3, a positive electrode current collecting terminal 4, a negative electrode current collecting terminal 5, an electrolytic solution 6, a positive electrode external terminal 7, a negative electrode external terminal 8, and a liquid injection unit. Includes 20 and.

The electrode body 2 is formed by winding the positive electrode sheet 10, the separator 11, and the negative electrode sheet 12 in a laminated state. The electrode body 2 is formed in a flat shape. The electrode body 2 includes a positive electrode 13 and a negative electrode 14.

The storage case 3 includes a case main body 15 which is an outer case and a top surface member 16. The case body 15 is formed with an opening that opens upward. The upper surface member 16 is arranged so as to close the opening above the case body 15. The outer peripheral edge of the upper surface member 16 is welded to the opening edge of the opening of the case body 15. The storage case 3 is made of, for example, aluminum or an aluminum alloy.

In the manufacturing process of the secondary battery 1 as described above, the upper surface member 16 is welded to the case body, and the electrolytic solution is injected from the liquid injection unit 20 provided in the upper surface member 16 with the electrode body housed. A liquid process is provided.

Regarding the manufacturing process of such a secondary battery, until the injection step of injecting the electrolytic solution into the storage case 3 of the secondary battery 1 is performed, for example, the opening of the injecting portion 20 using a cap. It is conceivable to close the (injection port) and fix it with a magnet.

However, depending on the manufacturing process of the secondary battery 1, the magnet for fixing the cap may be removed, and the cap may be removed from the liquid injection unit 20 during the period when the magnet is removed. On the other hand, by strengthening the connection between the cap and the liquid injection unit 20 by changing the material and dimensions of the cap, it is possible to close the liquid injection port without a magnet, but the cap is used in the liquid injection process. It may not be possible to easily remove the liquid from the injection unit 20.

Therefore, in the present embodiment, the upper surface member 16 is provided with a lid portion and a recessed portion. The recess is movable between a first position where a liquid injection port is formed on the bottom surface and a lid portion closes the liquid injection port and a second position where the lid portion is separated from the liquid injection port. It is formed. The sliding surface of the bottom surface of the recess with the lid is inclined so that the first position is lower than the second position.

In this way, the sliding surface of the bottom surface of the recess with the lid portion is inclined so that the first position is lower than the second position. Therefore, for example, the position of the lid portion is the first position. In this case, the movement of the lid portion to the second position can be suppressed by its own weight. On the other hand, at the time of injecting liquid, the position of the lid portion is moved to the second position by the operator, so that the injecting port can be easily exposed.

Hereinafter, such a structure will be described in detail with reference to FIGS. 2 to 6. FIG. 2 is an enlarged view of the broken line frame of FIG. Further, FIG. 3 is a perspective view of the upper surface member 16 when the lid portion 22 is in the first position.

As shown in FIG. 2, the liquid injection portion 20 includes a lid portion 22 and a recess 26. A liquid injection port 24 is formed on the bottom surface of the recess 26. The recess 26 is well known so that the lid 22 can be moved between the first position where the lid 22 closes the liquid injection port 24 and the second position where the lid 22 is separated from the liquid injection port 24. It is formed using a processing method. FIG. 2 shows the configuration of the liquid injection portion 20 when the lid portion 22 is in the first position to close the liquid injection port 24. As shown in FIG. 2, the sliding surface of the bottom surface of the recess 26 with the lid portion 22 is inclined so that the first position is lower than the second position. The bottom surface of the lid portion 22 (contact surface with the bottom surface of the recess 26) is inclined in the same manner as the bottom surface of the recess 26, and when the position of the lid portion 22 is the first position, the upper surface and the upper surface of the lid portion 22 The upper surface of the member 16 is substantially the same plane. A predetermined groove 28 is formed on the bottom surface side of the lid 22.

As shown in FIG. 3, the lid portion 22 has a substantially rectangular shape when viewed from above. The widthwise end face of the lid 22 is provided so as to abut or have a predetermined gap with the inner wall of the recess 26. The length of the recess 26 in the lateral direction of the paper surface is formed to be longer than the length of the lid portion 22 in the lateral direction of the paper surface. As a result, the lid portion 22 can slide in the lateral direction of the paper surface while being housed in the recess 26. FIG. 3 shows a case where the lid portion 22 is in the first position, and the liquid injection port 24 formed on the bottom surface of the recess 26 is in a state of being closed by the lid portion 22.

FIG. 4 is a diagram showing a sliding surface with the bottom surface of the recess 26 on the back side of the lid portion 22. As shown in FIG. 4, a groove 28 is formed on the sliding surface of the lid 22 with the bottom surface of the recess 26 from the intermediate position of the longitudinal end of the lid 22 to the vicinity of the center of the lid 22. The groove portion 28 is formed so as to communicate the liquid injection port 24 and the longitudinal end portion of the groove portion 28 when the lid portion 22 is in the first position.

FIG. 5 is a cross-sectional view of the liquid injection portion 20 when the lid portion 22 is in the second position. Further, FIG. 6 is a perspective view of the upper surface member 16 when the lid portion 22 is in the second position.

As shown in FIGS. 5 and 6, for example, when the lid portion 22 is in the second position by being moved from the first position along the longitudinal direction of the recess 26, the lid portion 22 is noted. It is located away from the liquid port 24. As a result, the upper part of the liquid injection port 24 is opened, and the liquid injection port 24 is exposed. As a result, the electrolytic solution can be injected from above.

The manufacturing method of the secondary battery 1 configured as described above will be described in detail. FIG. 7 is a manufacturing flow chart showing a manufacturing process of the secondary battery 1. The manufacturing process of the secondary battery 1 includes a top unit assembly process S1, an electrode body connecting process S2, an accommodating process S3, a welding process S4, a liquid injection process S5, and a sealing process S6.

FIG. 8 is a front view showing the upper surface unit assembly process S1. In the upper surface unit assembly step S1, the upper surface member 16 is assembled with the positive electrode current collecting terminal 4, the negative electrode current collecting terminal 5, the positive electrode external terminal 7, the negative electrode external terminal 8, and the lid portion 22 to form the upper surface unit 75. Form. At this time, the lid portion 22 is in a state of being moved to the first position. As a result, foreign matter is prevented from being mixed through the liquid injection port 24 until the liquid injection step S5.

FIG. 9 is a front view showing the electrode body connecting step S2. The electrode body connecting step S2 is a step of welding the electrode body 2 to the upper surface unit 75. Specifically, it includes a step of welding the positive electrode current collecting terminal 4 to the positive electrode 13 of the electrode body 2 and a step of welding the negative electrode current collecting terminal 5 to the negative electrode 14 of the electrode body 2.

FIG. 10 is a front view showing the accommodating step S3. In the accommodating step S3, the electrode body 2 welded to the upper surface unit 75 is accommodating in the case main body 15. In this step, the upper surface member 16 is arranged at the opening edge of the case body 15.

FIG. 11 is a front view schematically showing the welding process S4. The welding step S4 is a step of welding the outer peripheral edge portion of the upper surface member 16 to the opening edge portion of the case body 15. In this step, the opening edge portion of the case body 15 and the outer peripheral edge portion of the upper surface member 16 are laser-welded while the shield gas 77 is sprayed from the nozzle 76 toward the housing case 3. As the shield gas 77, for example, nitrogen gas or the like can be adopted.

FIG. 12 is a front view schematically showing the liquid injection step S5. The liquid injection step S5 is a step of injecting the electrolytic solution of the secondary battery 1 into the storage case 3. In the liquid injection step S5, the inside of the storage case 3 is dried, the lid 22 is moved to the second position, and the electrolytic solution is poured into the inside of the storage case 3 via the exposed liquid injection port 24. Includes a liquiding process.

In the process of drying the inside of the storage case 3, the lid portion 22 is in the first position to prevent foreign matter from entering, and the groove portion 28 provided on the back side of the lid portion 22 serves as an air passage in the storage case 3. Promotes drying.

In the step of injecting the electrolytic solution, the lid portion 22 is moved from the first position to the second position. As a result, the electrolytic solution is injected through the injection port 24 by exposing the injection port 24. After the liquid injection step, the lid portion 22 is moved from the second position to the first position again. This makes it possible to prevent foreign matter from entering through the liquid injection port 24 after the liquid injection. Further, the gas generated from the electrolytic solution in the storage case 3 is discharged to the outside of the storage case 3 via the groove portion 28 provided on the back side of the lid portion 22.

FIG. 13 is a diagram showing a sealing step S6. The sealing step S6 is a step of sealing the storage case 3. The sealing step S6 includes a step of moving the lid portion 22 to the first position and a step of welding the entire circumference (including the end portion of the groove portion 28) of the lid portion 22 in a state where the liquid injection port 24 is closed. include. By welding the entire circumference of the lid portion 22 at the first position, the liquid injection port 24 is closed and the storage case 3 is sealed.

As described above, according to the secondary battery 1 according to the present embodiment, the sliding surface of the bottom surface of the recess 26 with the lid portion 22 is inclined so that the first position is lower than the second position. Therefore, for example, when the position of the lid portion 22 is the first position, the movement of the position of the lid portion 22 to the second position can be suppressed by its own weight. On the other hand, at the time of injecting liquid, the position of the lid portion 22 is moved to the second position, so that the injecting port 24 can be easily exposed. Therefore, it is possible to provide a secondary battery capable of easily exposing the liquid injection port in the liquid injection step while reliably closing the liquid injection port until the liquid injection step.

For example, when the cap for closing the injection port 24 is repeatedly used, if foreign matter remains on the cap due to insufficient cleaning in the cleaning process for reusing the cap, it will be stored in the storage case 3 when it is reused. Although there is a possibility that foreign matter may be mixed in, the lid portion 22 in the present embodiment is not reused and is welded to the upper surface member 16 as a member constituting the storage case 3, so that the above-mentioned factors are taken. It is possible to suppress the contamination of foreign matter due to the above.

Further, the increase in the number of parts can be suppressed as compared with the case where the cap is reused, and since it is not necessary to perform a process such as a cleaning step, an increase in manufacturing cost can be suppressed.

Further, since the lid portion 22 can be housed in the recess 26, it is possible to prevent the lid portion 22 from falling off from the upper surface member 16 in the manufacturing process of the secondary battery 1.

Hereinafter, modification examples will be described.
In the above-described embodiment, the moving direction of the lid portion 22 has been described as being the longitudinal direction of the recess 26, but the recess 26 may be formed so that the lid portion 22 can move in the width direction.

Further, in the above-described embodiment, the bottom surface of the recess 26 is tilted with respect to the top surface of the top surface member 16, so that the first position on the sliding surface of the bottom surface of the recess 26 with the lid portion 22 is larger than the second position. Although it is tilted so as to be low, it is not particularly limited to such a configuration.

FIG. 14 is a cross-sectional view of the liquid injection portion 20 when the lid portion 22 in the modified example is in the first position. Further, FIG. 15 is a cross-sectional view of the liquid injection portion 20 when the lid portion 22 in the modified example is in the second position.

As shown in FIGS. 14 and 15, in this modification, the portion of the upper surface member 16 where the recess is provided may be inclined.

Even with such a configuration, the sliding surface of the bottom surface of the recess 26 with the lid portion 22 is inclined so that the first position is lower than the second position. Therefore, when the position of the lid portion 22 is the first position, the movement of the position of the lid portion 22 to the second position can be suppressed by its own weight. On the other hand, at the time of liquid injection, the liquid injection port can be easily exposed by moving the lid portion 22 to the second position.

In addition, the above-mentioned modification may be carried out by appropriately combining all or a part thereof.
It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present disclosure is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Secondary battery, 2 Electrode body, 3 Storage case, 4 Positive electrode current collector terminal, 5 Negative electrode current collector terminal, 6 Electrolyte, 7 Positive electrode external terminal, 8 Negative electrode external terminal, 10 Positive electrode sheet, 11 Separator, 12 Negative electrode sheet, 13 Positive electrode, 14 Negative electrode, 15 Case body, 16 Top surface member, 20 Injectable part, 22 Lid part, 24 Injectable port, 26 Recessed part, 28 Groove part, 75 Top surface unit, 76 Nozzle, 77 Shield gas.

Claims (1)

With the outer case,
The electrode body housed inside the outer case and
It is provided with a top surface member provided on the upper part of the outer case and provided with a liquid injection port and a lid portion provided so as to close the liquid injection port.
The upper surface member is provided with a recess.
The liquid injection port is formed on the bottom surface of the recess, and the recess is a first position where the lid portion closes the liquid injection port and a second position where the lid portion is separated from the liquid injection port. Formed to be movable between positions
The sliding surface of the bottom surface of the recess with the lid is inclined so that the first position is lower than the second position.
A groove is formed on the bottom surface of the lid.
A secondary battery in which the bottom surface of the lid portion excluding the groove portion is positioned so as to close the liquid injection port when the lid portion is in the first position.

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