JP3827753B2 - Injection method for battery electrolyte - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for injecting a battery electrolyte suitable for injecting an electrolyte into a battery having poor permeability, such as a lithium battery.
[0002]
[Prior art]
In the battery manufacturing process, as a conventional simple method for injecting the electrolyte into the battery, the electrolyte is simply dropped from the upper part of the unsealed battery opening via the supply pipe to the battery element. A method of permeation is known.
[0003]
However, since this method is carried out under normal pressure, it takes a lot of time to inject a battery with poor electrolyte permeability, and improvement in productivity cannot be expected. On the other hand, a method of injecting an electrolytic solution while applying centrifugal force to the battery has also been attempted, but this has not led to a significant reduction in injection time.
[0004]
In order to increase the injection rate, an injection chamber is provided to seal the opening of the unsealed battery, a supply pipe is connected between the electrolyte tank and the injection chamber, and the inside of the battery is set to a reduced pressure state. A method of injecting an electrolytic solution in a tank into a battery via a liquid supply pipe has been practiced.
[0005]
In this injection method, although the injection work can be shortened, the electrolytic solution accumulates on the inner wall of the opening of the unsealed battery after the injection of the electrolytic solution, or sometimes the electrolytic solution overflows from the opening. There is. This is because the injection rate is faster than the rate at which the electrolytic solution penetrates into the wound body. For this reason, if the inner wall of the battery opening remains wet with the electrolyte, the battery case and the sealing plate are not sufficiently kept in contact with the battery when sealing the battery, and the leakage resistance deteriorates. Become.
[0006]
In order to solve this problem, the injection chamber that seals the opening of the unsealed battery and the electrolyte tank are connected by a liquid supply pipe, and the inside of the battery and the electrolyte tank are set in a reduced pressure state. There has been proposed a method of injecting a predetermined amount of an electrolyte in an electrolyte tank into a battery via a supply pipe by adjusting an electrolyte injection speed by adjusting the pressure difference.
[0007]
[Problems to be solved by the invention]
In the battery electrolyte injection method according to this proposal, the electrolyte is injected into the battery via the supply pipe while adjusting the electrolyte injection speed by adjusting the pressure difference between the battery and the electrolyte tank. The electrolyte can be injected at a rate that penetrates the wound body, and the inner wall of the opening of an unsealed battery is not wetted by the electrolyte, resulting in good adhesion between the battery case and the sealing plate Can be secured.
[0008]
However, in this method, unless the pressure difference or the like is kept strictly controlled, for example, when the degree of decompression in the electrolyte tank unexpectedly becomes larger than that in the battery, the electrolyte flows backward. Alternatively, the electrolyte may be excessively injected while the pressure inside the battery is insufficient, and in this case, the intended purpose is to prevent the electrolyte from adhering to the inner wall of the opening of the unsealed battery. Can't be done.
[0009]
The present invention has been made in view of the above circumstances, and even if an unexpected injection failure occurs, it is possible to quickly prevent this and inject the electrolyte into the battery in a short time and appropriately. An object of the present invention is to provide a method for injecting a battery electrolyte.
[0010]
[Means for Solving the Problems]
In order to achieve this object, a method for injecting battery electrolyte according to the present invention comprises connecting an injection chamber for sealing an opening of an unsealed battery and an electrolyte tank with a liquid supply pipe, While setting the reduced pressure state, set the inside of the electrolyte tank to a reduced pressure state smaller than the inside of the battery, and adjust the electrolyte injection speed by adjusting the pressure difference between the inside of the battery and the electrolyte tank. In the battery electrolyte injection method for injecting a predetermined amount of the electrolyte into the battery through the liquid supply pipe, the above-mentioned liquid supply pipe is provided with a check valve and an electrolytic solution shut-off mechanism or one of them. It is a thing.
[0011]
According to the present invention, the inside of the battery and the electrolytic solution tank are depressurized, and the electrolytic solution is injected by adjusting the injection rate of the electrolytic solution by adjusting the pressure difference between them. Can be injected at the same rate as the penetration rate, and the electrolyte does not adhere to the inner wall of the battery opening, preventing poor adhesion between the battery case and the sealing plate when sealing the battery, and improving leakage resistance. In addition, even if the pressure difference is not sufficiently managed, for example, even if the electrolyte tank is in a state where the pressure in the electrolyte tank is greatly reduced from that in the battery, the check valve can prevent backflow, and the electrolyte is not prepared. Even when an abnormal state excessively injected into the battery occurs, it is possible to prevent the excessive injection by the electrolyte solution and the disconnection mechanism and the disconnection operation. Will be achieved.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a cylindrical lithium battery as an example of a battery to which the battery electrolyte injection method of the present invention is applied.
[0013]
In FIG. 1, the battery 10 is manufactured as follows. First, the wound body 1 obtained by winding the positive electrode sheet 1A and the negative electrode sheet 1B in a spiral shape via the separator 1C is inserted into the battery case 4, and the negative electrode lead piece 2 is attached. Weld the battery case 4 to the inner bottom. Next, after a predetermined amount of electrolyte is injected into the wound body 1 from the central space 5 of the battery case 4, the positive electrode lead piece 3 is welded to the sealing plate 6. Finally, the sealing plate 6 is disposed on the groove portion 7 of the battery case 4 via the insulating gasket 8 and the upper end of the peripheral wall of the battery case 4 is crimped inward to complete.
[0014]
FIG. 2 is a longitudinal sectional view showing an outline of an apparatus for carrying out the method for injecting the electrolytic solution into the battery 10. In the figure, reference numeral 11 denotes a cap connected to the upper opening end 4a of the battery case 4 in the unsealed battery 10 via the seal packing 12, whereby the opening of the battery case 4 is opened. An injection chamber 13 for sealing is formed. The injection chamber 13 is connected to a vacuum pump (not shown) via the air discharge port 14, and is kept in a reduced pressure state, that is, a predetermined degree of vacuum.
[0015]
Reference numeral 15 denotes an electrolytic solution tank containing an electrolytic solution 16, and the tank 15 and the injection chamber 13 are connected via a liquid supply pipe 17, and the inside of the tank 15 is connected via an air discharge port 18. By connecting to a vacuum pump (not shown), the pressure is reduced, that is, a predetermined vacuum level smaller than that in the battery 10 is maintained.
[0016]
The liquid supply pipe 17 is provided with a backflow valve 19 for preventing the backflow of the electrolyte solution 16 even if the degree of vacuum in the electrolyte solution tank 15 becomes higher than that of the injection chamber 13 during the injection. The liquid supply pipe 17 is provided with an electrolyte injection valve 20 serving as an electrolyte stopper and a disconnecting mechanism that can forcibly stop the injection of the electrolyte 16 due to a pressure difference.
[0017]
In this configuration, when the electrolyte solution 16 is injected, the inside of the battery case 4 is depressurized by a vacuum pump. At this time, the injection valve 20 is closed so that the electrolyte solution 16 is not injected until the inside of the battery case 4 reaches a predetermined degree of vacuum. In parallel with this, the electrolytic solution tank 15 in which a predetermined amount of the electrolytic solution 16 has been charged in advance is decompressed to a predetermined degree of vacuum by a vacuum pump. When the inside of the battery case 4 and the inside of the electrolyte solution tank 15 reach a predetermined degree of vacuum, the liquid injection valve 20 is opened, and the electrolyte solution 16 is supplied from the electrolyte solution tank 15 through the liquid supply pipe 17. 4 is injected.
[0018]
At this time, the degree of vacuum in the battery case 4 is set higher than the degree of vacuum in the electrolyte tank 15, and the rate of injection of the electrolyte 16 into the battery case 4 is adjusted by setting this pressure difference. Is done. When the pressure difference is large, the injection speed is high, and when the pressure difference is small, the injection speed is low. The electrolyte solution 16 is injected at the same speed as that penetrates the wound body 1 by adjusting the pressure difference, and penetrates the wound body 1 without adhering to the inner wall of the opening of the battery 10, so that the liquid injection work is performed. Completed.
[0019]
At the time of this injection, even if the degree of vacuum in the electrolyte tank 15 is higher than the degree of vacuum in the battery case, the check valve 19 provided between the supply pipes causes the electrolyte 16 to flow backward. Is blocked. In addition, when a situation occurs in which liquid injection is inadvertently started before the degree of vacuum in the battery case 4 reaches a predetermined value, the liquid injection valve 20 is closed. It is not excessively injected into the electrolyte case 4. Therefore, the injection of the electrolyte solution 16 is performed under the condition of the electrolyte solution injection rate due to the pressure difference precisely while avoiding the abnormal state, and the above-described effect of preventing the adhesion of the electrolyte solution 16 is satisfactorily exhibited. As a result, the improvement of the liquid leakage resistance is guaranteed.
[0020]
The liquid supply pipe 17 may be provided with one of the check valve 19 and the liquid injection valve 20. However, by providing both 19 and 20 as in the above embodiment, the intended purpose can be achieved. It can be achieved more reliably.
[0021]
The present invention is not limited to the above-described embodiments, and can be modified and used without changing the gist. Further, in order to realize the method of injecting the electrolyte of the present invention, the apparatus as described in the above embodiment is used. However, when the method of the present invention is carried out, the configuration of the apparatus is particularly limited. Not.
[0022]
【The invention's effect】
According to the present invention, the electrolyte injection rate is adjusted by the pressure difference between the unsealed battery and the electrolyte tank, so that the electrolyte solution is injected. By not getting wet, the adhesion between the battery case and the sealing plate can be maintained sufficiently, and the leakage resistance can be greatly improved. In particular, the liquid supply between the electrolyte tank and the battery side can be improved. Since the pipe is provided with a check valve and an electrolyte solution or shut-off mechanism or one of them, even if an unexpected electrolyte injection abnormality occurs, this can be prevented and the above effects can be effectively used as they are. It can be demonstrated.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an example of a battery to which a battery electrolyte injection method of the present invention is applied.
FIG. 2 is a longitudinal sectional view showing an outline of an apparatus for carrying out the method for injecting the battery electrolyte.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Battery 13 Injection | pouring chamber 15 Electrolyte tank 16 Electrolyte 17 Supply liquid pipe 19 Check valve 20 Electrolyte liquid cutting | disconnection mechanism (injection valve)

Claims (1)

The filling chamber for sealing the opening of the unsealed battery and the electrolyte tank are connected by a liquid supply pipe, and the inside of the battery is set in a reduced pressure state, while the inside of the electrolyte tank is in a reduced pressure state smaller than that in the battery. A battery that adjusts the electrolyte injection speed by adjusting the pressure difference between the battery and the electrolyte tank and injects a predetermined amount of the electrolyte in the electrolyte tank into the battery via the liquid supply pipe A method for injecting an electrolytic solution for a battery, comprising: a check valve and / or an electrolytic solution shut-off mechanism or one of them provided in the liquid supply pipe.

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