JP6838389B2 - Battery manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a battery including a liquid injection step of injecting an electrolytic solution into a battery case through a liquid injection hole provided in the battery case.

In manufacturing a battery, for example, after assembling a battery in which an electrode body is housed in a battery case, an electrolytic solution is injected into the battery case through a liquid injection hole provided in the battery case. .. In addition, Patent Document 1 is mentioned as a related prior art.

Japanese Unexamined Patent Publication No. 2015-219962

In the manufacture of the battery of Patent Document 1, as a method of injecting the electrolytic solution into the battery case, for example, after injecting a specified amount of the electrolytic solution at one time in a state where the inside of the battery case is depressurized from the atmospheric pressure, the electrolytic solution is injected. A method of returning the inside of the battery case to atmospheric pressure to promote impregnation of the electrolytic solution into the electrode body can be considered.
However, while the electrolytic solution is being injected, the impregnation rate of the electrolytic solution into the electrode body is slow. Therefore, it is necessary to slowly inject the electrolytic solution according to the impregnation rate of the electrolytic solution into the electrode body so that the electrolytic solution does not overflow from the injection hole to the outside of the battery. Therefore, the injection time is long and the production cost of the battery is high.

The present invention has been made in view of the current situation, and an object of the present invention is to provide a method for manufacturing a battery, which can shorten the time required for the liquid injection step of injecting an electrolytic solution into a battery case.

One aspect of the present invention for solving the above-mentioned problems is a method for manufacturing a battery including a battery case having a liquid injection hole, an electrode body and an electrolytic solution housed in the battery case, and the above-mentioned battery. A liquid injection step of injecting the electrolytic solution through the liquid injection hole is provided in the case, and in the liquid injection step, the electrolytic solution is injected into the battery case with the inside of the battery case depressurized from atmospheric pressure. The liquid is started, and the liquid is injected while detecting the height of the liquid level of the injected electrolytic solution with the liquid amount sensor, and at least a part of the electrode body is immersed in the electrolytic solution, and the liquid is injected. When the liquid level sensor detects that the liquid level of the electrolytic solution has reached a predetermined first reference height, the first liquid injection step of stopping the injection of the electrolytic solution and the inside of the battery case A liquid that raises the pressure pressure above the pressure pressure at the time of performing the first injection step and lowers the liquid level of the electrolytic solution below the liquid level of the electrolytic solution at the end of the first liquid injection step. After the surface lowering step, the second injection step of restarting the injection of the electrolytic solution and injecting the electrolytic solution to a specified amount or a specified height, and the second injection step, the above solution of the electrolytic solution. It is a method of manufacturing a battery having a liquid level adjusting step of waiting until the surface drops to a predetermined second reference height.

When trying to inject a large amount of electrolytic solution at one time, as described above, the electrolytic solution is injected according to the impregnation rate of the electrolytic solution into the electrode body so that the electrolytic solution does not overflow from the injection hole to the outside of the battery. Since the liquid must be injected slowly, it takes a long time to inject the liquid.
On the other hand, in the above-mentioned manufacturing method, after injecting the electrolytic solution under reduced pressure in the first liquid injection step, the air pressure inside the battery case is increased in the liquid level lowering step to impregnate the electrode body with the electrolytic solution. And lowers the level of the electrolyte. After that, the injection of the electrolytic solution is restarted in the second injection step, and the electrolytic solution is injected to a specified amount or a specified height. In this way, a liquid level lowering step is provided in the middle of the injection of the electrolytic solution to promote impregnation of the electrolytic solution into the electrode body and lower the liquid level of the electrolytic solution, whereby the first liquid injection step and the second liquid injection are performed. The injection speed of the electrolytic solution in the process can be made faster than that in the case of injecting the electrolytic solution at one time, and the time of the injection process can be shortened.

In the "first liquid injection step", as a method of "stopping the injection of the electrolytic solution while at least a part of the electrode body is immersed in the electrolytic solution", for example, as will be described later, the liquid of the electrolytic solution A method of stopping the injection of the electrolytic solution when the surface reaches the reference height (the reference height at which at least a part of the electrode body is immersed in the electrolytic solution) can be mentioned. Another method is to stop the injection of the electrolytic solution when the injection amount of the electrolytic solution reaches a predetermined amount (a predetermined amount at which at least a part of the electrode body is immersed in the electrolytic solution).

In the "second liquid injection step", the electrolytic solution may be injected with the inside of the battery case at atmospheric pressure, or the electrolytic solution may be injected with the inside of the battery case depressurized from the atmospheric pressure. .. When the inside of the battery case is depressurized in the second filling step, the pressure may be reduced to the same pressure as in the first filling step, or to a pressure higher or lower than the pressure in the first filling step. You may.

Further, in the above-mentioned battery manufacturing method, in the first liquid injection step, when the liquid level of the electrolytic solution reaches a reference height at which at least a part of the electrode body is immersed in the electrolytic solution. In addition, it is preferable to use a method for manufacturing a battery that stops the injection of the electrolytic solution.

There are variations in the volume of the electrode body of the battery and the rate of impregnation of the electrolytic solution injected into the battery case into the electrode body. Therefore, as described above, when the method of stopping the injection of the electrolytic solution when the injection amount of the electrolytic solution reaches a predetermined amount is adopted in the first injection step, the predetermined amount of the electrolytic solution is used. Depending on the battery, a part of the electrolytic solution may overflow from the liquid injection hole to the outside of the battery when the liquid is injected.
On the other hand, in the above-mentioned battery manufacturing method, in the first liquid injection step, the injection of the electrolytic solution is stopped when the liquid level of the electrolytic solution reaches the reference height, so that the electrolytic solution is discharged from the injection hole. It is possible to surely prevent the battery from overflowing to the outside.

It is a perspective view of the battery which concerns on embodiment. It is a vertical sectional view of the battery which concerns on embodiment. It is explanatory drawing of the liquid injection apparatus which concerns on embodiment. It is a flowchart which shows the manufacturing method of the battery which concerns on embodiment. It is explanatory drawing which shows the state that the liquid level of the electrolytic solution rises to the 1st reference height in the 1st liquid injection step of the liquid injection process which concerns on embodiment. It is explanatory drawing which shows the state which the liquid level of the electrolytic solution lowered in the liquid level lowering process of the liquid injection step which concerns on embodiment. It is explanatory drawing which shows the state of injecting the electrolytic solution in the 2nd liquid injection process of the liquid injection process which concerns on embodiment. It is explanatory drawing which shows the state that the liquid level of the electrolytic solution dropped to the 2nd reference height in the liquid level adjustment step of the liquid injection process which concerns on embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a perspective view and a vertical sectional view of the battery 1 according to the present embodiment. In the following description, the battery thickness direction BH, the battery horizontal direction CH, and the battery vertical direction DH of the battery 1 are defined as the directions shown in FIGS. 1 and 2. The battery 1 is a square and sealed lithium ion secondary battery mounted on a vehicle such as a hybrid car, a plug-in hybrid car, or an electric vehicle. The battery 1 is composed of a battery case 10, an electrode body 20 housed therein, a positive electrode terminal member 50 supported by the battery case 10, a negative electrode terminal member 60, and the like (see FIGS. 1 and 2). Further, the electrolytic solution 15 is housed in the battery case 10, a part of which is impregnated in the electrode body 20, and a part of which is accumulated in the bottom of the battery case 10.

Of these, the battery case 10 has a rectangular parallelepiped shape and is made of metal (aluminum in this embodiment). The battery case 10 is composed of a bottomed square tubular case body member 11 having an opening only on the upper side, and a rectangular plate-shaped case lid member 13 welded in a form of closing the opening of the case body member 11. To. The case lid member 13 is provided with a liquid injection hole 13h, and is hermetically sealed by the sealing member 17. The liquid injection hole 13h is used when the electrolytic solution 15 is injected into the battery case 10, as will be described later.

Further, a positive electrode terminal member 50 made of aluminum is fixed to the case lid member 13 in a state of being insulated from the case lid member 13. The positive electrode terminal member 50 is connected to and conducts with the positive electrode plate 21 of the electrode body 20 in the battery case 10, while penetrating the case lid member 13 and extending to the outside of the battery. Further, a negative electrode terminal member 60 made of copper is fixed to the case lid member 13 in a state of being insulated from the case lid member 13. The negative electrode terminal member 60 is connected to and conducts with the negative electrode plate 31 of the electrode body 20 in the battery case 10, while penetrating the case lid member 13 and extending to the outside of the battery.

The electrode body 20 has a flat shape and is housed in the battery case 10 in a state of being laid on its side. A bag-shaped insulating film enclosure 19 made of an insulating film is arranged between the electrode body 20 and the battery case 10. The electrode body 20 is formed by stacking a band-shaped positive electrode plate 21 and a band-shaped negative electrode plate 31 on top of each other via a pair of band-shaped separators 41 and 41, winding them around an axis, and compressing them in a flat shape. The positive electrode plate 21 is formed by providing a strip-shaped positive electrode active material layer at predetermined positions on both main surfaces of a positive electrode current collecting foil made of a strip-shaped aluminum foil. The positive electrode active material layer is composed of a positive electrode active material, a conductive material and a binder. Further, the negative electrode plate 31 is provided with a negative electrode active material layer at predetermined positions on both main surfaces of a negative electrode current collector foil made of a strip-shaped copper foil. The negative electrode active material layer is composed of a negative electrode active material, a binder and a thickener. Further, the separator 41 is a porous film made of resin, and has a band shape and a film shape.

Next, a method for manufacturing the battery 1 will be described (see FIG. 4). First, in the assembly step S1, the battery 1 is assembled. Specifically, the positive electrode plate 21 and the negative electrode plate 31 are wound on top of each other via a pair of separators 41 and 41 and compressed into a flat shape to form the electrode body 20. Next, the case lid member 13 is prepared, and the positive electrode terminal member 50 and the negative electrode terminal member 60 are fixedly attached to the case lid member 13 (see FIGS. 1 and 2). After that, the positive electrode terminal member 50 and the negative electrode terminal member 60 are welded to the positive electrode plate 21 and the negative electrode plate 31 of the electrode body 20, respectively. Next, the electrode body 20 is covered with the insulating film enclosing body 19, and these are inserted into the case main body member 11, and the opening of the case main body member 11 is closed with the case lid member 13. Then, the case body member 11 and the case lid member 13 are welded to form the battery case 10.

Next, the liquid injection step S2 is performed, and a specified amount of the electrolytic solution 15 is injected into the battery case 10 through the liquid injection holes 13h provided in the case lid member 13. This liquid injection step S2 is performed using the liquid injection device 100 shown in FIG. The liquid injection device 100 includes a liquid injection nozzle 110, an electrode 120, a detection device 130, a vacuum chamber 140, an atmosphere opening valve 147, an electrolytic solution tank 150, a liquid injection valve 155, a control device 160, and the like.

Of these, the vacuum chamber 140 is composed of a bottomed square tubular chamber body member 141 having an opening only on the upper side, and a rectangular plate-shaped chamber lid member 143 that closes the opening of the chamber body member 141. A battery 1 is housed inside the vacuum chamber 140, as will be described later. A vacuum pump 145 is attached to the vacuum chamber 140, and by operating the vacuum pump 145, the inside of the vacuum chamber 140 can be depressurized. Further, an air release valve 147 is attached to the vacuum chamber 140, and by opening the air release valve 147, the inside of the vacuum chamber 140 can be opened to the atmosphere. Further, a pressure sensor 149 is attached to the vacuum chamber 140, and the air pressure in the vacuum chamber 140 can be measured by the pressure sensor 149. Further, the liquid injection nozzle 110 and the electrode 120 are firmly fixed to the chamber lid member 143 of the vacuum chamber 140 with a predetermined interval KC (see FIG. 5).

The liquid injection nozzle 110 is cylindrical and made of metal (specifically, stainless steel). The electrolytic solution 15 flows through the inside of the liquid injection nozzle 110, and the electrolytic solution 15 is discharged from the tip portion 110s of the liquid injection nozzle 110. The liquid injection nozzle 110 is fixed perpendicular to the chamber lid member 143 so that its extension direction is parallel to the chamber vertical direction FH of the vacuum chamber 140.
Further, the electrode 120 has a round bar shape and is made of metal (specifically, stainless steel). The extension direction of the electrode 120 is parallel to the vertical direction FH of the chamber (parallel to the liquid injection nozzle 110), and the tip portion 120s of the electrode 120 is at the same height as the tip portion 110s of the liquid injection nozzle 110. , Is fixed perpendicular to the chamber lid member 143.

The detection device 130 is electrically connected to the liquid injection nozzle 110 via the wiring 131 and to the electrode 120 via the wiring 133, and constitutes the liquid volume sensor 105 by these. The detection device 130 was injected by applying a constant voltage between the injection nozzle 110 and the electrode 120 and measuring the magnitude of the current flowing between the injection nozzle 110 and the electrode 120. The height of the electrolytic solution 15 at a liquid level of 15 m is measured, and this measurement signal can be output.

The electrolytic solution tank 150 is a tank for storing the electrolytic solution 15, and is connected to the base end portion 110t of the liquid injection nozzle 110 via the liquid flow passage 151. A flow meter 153 and a liquid injection valve 155 are arranged in the middle of the liquid flow passage 151, respectively. Since the flow meter 153 can measure the amount of the electrolytic solution 15 flowing through the liquid flow passage 151, the amount of the electrolytic solution 15 discharged from the tip 110s of the liquid injection nozzle 110 and injected into the battery case 10. Can be measured. When the liquid injection valve 155 is opened, the electrolytic liquid 15 flows through the liquid flow passage 151, the electrolytic liquid 15 is supplied to the liquid injection nozzle 110, and the electrolytic liquid is supplied from the tip 110s of the liquid injection nozzle 110. 15 is released. On the other hand, when the liquid injection valve 155 is closed, the flow of the electrolytic liquid 15 in the liquid flow passage 151 is stopped, so that the discharge (liquid injection) of the electrolytic liquid 15 from the tip 110s of the liquid injection nozzle 110 is also stopped.

The control device 160 includes a CPU, a ROM, and a RAM (not shown), and has a microcomputer that is operated by a predetermined control program stored in the ROM or the like. A pressure sensor 149, a flow meter 153, a detection device 130, a vacuum pump 145, an atmosphere release valve 147 and a liquid injection valve 155 are connected to the control device 160, respectively, and the pressure sensor 149, the flow meter 153 and the detection device 130 are connected to each other. Based on each signal of, the operation of the vacuum pump 145, the opening / closing of the atmosphere release valve 147, and the opening / closing of the liquid injection valve 155 are controlled.

Prior to the liquid injection step S2, the above-mentioned battery 1 is placed at a predetermined position in the chamber main body member 141 of the vacuum chamber 140 in a state where the battery 1 stands upright so that the battery vertical direction DH is parallel to the chamber vertical direction FH. .. After that, the opening of the chamber body member 141 is closed by the chamber lid member 143, and the liquid injection nozzle 110 and the electrode 120 fixed to the chamber lid member 143 are inserted into the battery case 10 through the liquid injection hole 13h of the battery 1. (See Fig. 3).

First, in the first liquid injection step S21 of the liquid injection step S2, the injection of the electrolytic solution 15 into the battery case 10 is started in a state where the inside of the battery case 10 is depressurized from the atmospheric pressure, and the liquid level of the electrolytic solution 15 is started. When 15 m reaches the first reference height LA (see FIG. 5), the injection of the electrolytic solution 15 is temporarily stopped. In the present embodiment, the first reference height LA is set at a position higher than the upper end 20p of the electrode body 20.

Specifically, after closing the atmosphere release valve 147 by the control device 160, the vacuum pump 145 is operated to reduce the pressure in the vacuum chamber 140. Then, when the air pressure in the vacuum chamber 140 measured by the pressure sensor 149 drops to a predetermined pressure, the liquid injection valve 155 is opened. As a result, the electrolytic solution 15 stored in the electrolytic solution tank 150 is supplied to the liquid injection nozzle 110 through the liquid flow passage 151, and the electrolytic solution 15 is discharged into the battery case 10 from the tip 110s of the liquid injection nozzle 110.

After that, when the liquid level sensor 105 detects that the liquid level 15 m of the injected electrolyte 15 has reached the first reference height LA, the control device 160 closes the liquid injection valve 155. As a result, the flow of the electrolytic solution 15 flowing through the liquid flow passage 151 is stopped, and the injection of the electrolytic solution 15 into the battery case 10 is stopped. In the present embodiment, as described above, the first reference height LA is set at a position higher than the upper end 20p of the electrode body 20, and therefore, at the end of the first liquid injection step S21, the entire electrode body 20 is formed. Is immersed in the electrolytic solution 15.
In this way, when the liquid level 15 m of the electrolytic solution 15 reaches the first reference height LA, the injection of the electrolytic solution 15 is temporarily stopped, so that the electrolytic solution 15 overflows from the injection hole 13h to the outside of the battery. Can be reliably prevented.

After the first liquid injection step S21, in the liquid level lowering step S22, the air pressure inside the battery case 10 is raised above the air pressure when the first liquid injection step S21 is performed to raise the liquid level of the electrolytic solution 15 to 15 m. , The liquid level of the electrolytic solution 15 at the end of the first liquid injection step S21 is lowered from 15 m (specifically, the first reference height LA) (see FIG. 6).
Specifically, the control device 160 opens the atmospheric release valve 147 to increase the air pressure in the vacuum chamber 140. Then, since the impregnation of the injected electrolytic solution 15 into the electrode body 20 is promoted, the liquid level 15 m of the electrolytic solution 15 gradually decreases from the first reference height LA. In the present embodiment, the liquid level lowering step S22 is performed until the air pressure in the vacuum chamber 140 measured by the pressure sensor 149 rises to a predetermined pressure, and when the air pressure in the vacuum chamber 140 reaches a predetermined pressure, the liquid level is lowered. Step S22 is completed. As a result, in the present embodiment, the liquid level 15m of the electrolytic solution 15 is lowered to a position lower than the upper end 20p of the electrode body 20.

Next, in the second liquid injection step S23, the injection of the electrolytic solution 15 is restarted, and a specified amount of the electrolytic solution 15 is injected (see FIG. 7).
Specifically, the liquid injection valve 155 is opened by the control device 160, and the injection of the electrolytic solution 15 into the battery case 10 is restarted under atmospheric pressure. Then, when the flow rate of the electrolytic solution 15 flowing through the liquid flow passage 151 measured by the flow meter 153, that is, the amount of the electrolytic solution 15 injected into the battery case 10 reaches a specified amount, the liquid injection valve 155 Is closed, and the injection of the electrolytic solution 15 into the battery case 10 is completed. In this way, a specified amount of the electrolytic solution 15 is injected into the battery case 10.

Then, in the liquid level adjusting step S24, wait until the liquid level 15 m of the electrolytic solution 15 drops to the second reference height LB (see FIG. 8). Since the injected electrolytic solution 15 gradually impregnates the electrode body 20, after the injection of the electrolytic solution 15 is completed (after the second injection step S23), the liquid level of the electrolytic solution 15 gradually rises to 15 m with the passage of time. It will decrease to. When the liquid level 15 m of the electrolytic solution 15 reaches the second reference height LB, the liquid level adjusting step S24 is completed. As a result, a sufficiently large space GC can be secured in the upper part of the battery case 10, so that it is possible to prevent welding defects from occurring in the sealing step S3, as will be described later.
After that, the chamber lid member 143 is removed from the chamber body member 141, and the liquid injection nozzle 110 and the electrode 120 fixedly attached to the chamber lid member 143 are taken out from the liquid injection hole 13h of the battery 1. After that, the battery 1 is taken out from the chamber main body member 141. Thus, the liquid injection step S2 is completed.

Next, in the sealing step S3, the liquid injection hole 13h is sealed with the sealing member 17. Specifically, with the sealing member 17 blocking the liquid injection hole 13h from the outside of the battery, the sealing member 17 is welded to the battery case 10 by laser welding to seal the liquid injection hole 13h. After that, the battery 1 is charged for the first time. In addition, various inspections are performed on the battery 1. Thus, the battery 1 is completed.

By the way, when the electrolytic solution 15 is injected into the battery case 10 without using the liquid amount sensor 105, the electrolytic solution 15 overflows from the liquid injection hole 13h of the battery case 10 to the outside of the battery, and the electrolytic solution 15 is not used. Even if 15 does not overflow, a part of the electrolytic solution 15 may adhere to the inner side surface 13b (lower surface in FIG. 5) of the case lid member 13. Further, even when the liquid injection step S2 is performed as described above using the liquid volume sensor 105, if the first reference height LA is set at a position close to the inner side surface 13b of the case lid member 13, one of the electrolytic solutions 15 is set. The portion may adhere to the inner side surface 13b of the case lid member 13.

Then, when the sealing member 17 is welded in the sealing step S3, the electrolytic solution 15 adhering to the vicinity of the liquid injection hole 13h in the inner side surface 13b of the case lid member 13 is vaporized by the heat generated by the welding. , The pressure inside the battery case 10 rises. As a result, the molten pool formed between the sealing member 17 and the liquid injection hole 13h may be lifted by the pressure in the battery case 10 and cause welding failure.

On the other hand, in the present embodiment, in the first liquid injection step S21, when the liquid level 15 m of the electrolytic solution 15 reaches the first reference height LA, the injection of the electrolytic solution 15 is stopped, so that the electrolytic solution is stopped. It is possible to prevent 15 from adhering to the inner side surface 13b of the case lid member 13.
Further, in the present embodiment, after waiting for the liquid level 15 m of the electrolytic solution 15 to drop to the second reference height LB in the liquid level adjusting step S24, a sufficiently large space GC is secured in the upper part of the battery case 10. The sealing step S3 is performed. As a result, if a large space GC exists in the upper part of the battery case 10, even if the electrolytic solution 15 adhering to the inner side surface 13b of the case lid member 13 is vaporized in the sealing step S3, the pressure in the battery case 10 is reached. Can be prevented from rising significantly, and the above-mentioned welding defects can be prevented from occurring.

As described above, in the method for manufacturing the battery 1, the liquid injection step S2 includes a first liquid injection step S21, a liquid level lowering step S22, and a second liquid injection step S23. As described above, when a large amount of the electrolytic solution 15 is to be injected into the battery case 10 at one time, the electrolytic solution 15 is directed to the electrode body 20 of the electrolytic solution 15 so as not to overflow from the injection hole 13h to the outside of the battery. Since the electrolytic solution 15 must be slowly injected according to the impregnation rate of the above, the injection time is long.

On the other hand, in the above-mentioned manufacturing method of the battery 1, after injecting the electrolytic solution 15 in a reduced pressure state in the first liquid injection step S21, the air pressure in the battery case 10 is increased in the liquid level lowering step S22 to perform electrolysis. The impregnation of the liquid 15 into the electrode body 20 is promoted, and the liquid level of the electrolytic liquid 15 is lowered by 15 m. Then, in the second liquid injection step S23, the injection of the electrolytic solution 15 is restarted, and the electrolytic solution 15 is injected in a specified amount. In this way, the liquid level lowering step S22 is provided in the middle of the injection of the electrolytic solution 15 to promote the impregnation of the electrolytic solution 15 into the electrode body 20 and lower the liquid level 15 m of the electrolytic solution 15 to lower the first liquid injection. The injection speed of the electrolytic solution 15 in the steps S21 and the second injection step S23 can be made faster than when a specified amount of the electrolytic solution 15 is injected at one time, and the time of the injection step S2 can be shortened.

Further, the electrode body 20 of the battery 1 has a volume variation, and the impregnation rate of the electrolytic solution 15 injected into the battery case 10 into the electrode body 20 varies. Therefore, for example, in the first liquid injection step S21, when the method of stopping the injection of the electrolytic solution 15 when the injection amount of the electrolytic solution 15 reaches a predetermined amount is adopted, the electrolytic solution 15 is used. Depending on the battery 1, a part of the electrolytic solution 15 may overflow from the liquid injection hole 13h to the outside of the battery when a fixed amount of liquid is injected.
On the other hand, in the manufacturing method of the present embodiment, in the first liquid injection step S21, the injection of the electrolytic solution 15 is stopped when the liquid level 15 m of the electrolytic solution 15 reaches the first reference height LA. It is possible to reliably prevent the electrolytic solution 15 from overflowing to the outside of the battery from the liquid injection hole 13h.

Although the present invention has been described above in accordance with the embodiments, it is needless to say that the present invention is not limited to the above-described embodiments and can be appropriately modified and applied without departing from the gist thereof.
For example, in the embodiment, in the second liquid injection step S23, a predetermined amount of the electrolytic solution 15 is injected to finish the injection of the electrolytic solution 15, but the present invention is not limited to this. For example, the electrolytic solution 15 may be injected to a specified height by using the liquid amount sensor 105 described above.

1 Battery 10 Battery case 13h Liquid injection hole 15 Electrolyte 15m (of electrolytic solution) Liquid level 17 Sealing member 20 Electrode body 100 Liquid injection device 105 Liquid volume sensor 110 Liquid injection nozzle 120 Electrode LA 1st reference height LB 2nd Reference height S1 Assembly process S2 Lubrication process S21 First lubrication process S22 Liquid level lowering process S23 Second lubrication process S24 Liquid level adjustment process S3 Sealing process

Claims (1)

A method for manufacturing a battery including a battery case having a liquid injection hole and an electrode body and an electrolytic solution housed in the battery case.
A liquid injection step of injecting the electrolytic solution into the battery case through the liquid injection hole is provided.
The above liquid injection process
With the inside of the battery case depressurized below the atmospheric pressure, the injection of the electrolytic solution into the battery case is started, and the injection is performed while detecting the height of the liquid level of the injected electrolytic solution with the liquid level sensor. The liquid level sensor detects that at least a part of the electrode body is immersed in the electrolytic solution and the liquid level of the electrolytic solution reaches a predetermined first reference height. Then, the first injection step of stopping the injection of the electrolytic solution and the
The air pressure inside the battery case is raised above the air pressure at the time of performing the first liquid injection step, and the liquid level of the electrolytic solution is raised to the liquid level of the electrolytic solution at the end of the first liquid injection step. The liquid level lowering process and the lowering process
The second injection step of restarting the injection of the electrolytic solution and injecting the electrolytic solution to a specified amount or a specified height, and
A method for manufacturing a battery , comprising: after the second liquid injection step, a liquid level adjusting step of waiting until the liquid level of the electrolytic solution drops to a predetermined second reference height.

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