JP4575546B2 - Method for manufacturing prismatic alkaline storage battery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a prismatic alkaline storage battery.
[0002]
[Prior art]
In recent years, alkaline storage batteries have attracted attention as power sources for portable devices and portable devices, and as mobile power sources for electric vehicles, hybrid electric vehicles, and the like, and higher performance is required than ever. For example, a nickel-metal hydride secondary battery comprising a positive electrode made of an active material mainly composed of nickel hydroxide and a negative electrode made mainly of a hydrogen storage alloy has rapidly become a secondary battery with high energy density and excellent reliability. It is popular.
[0003]
Among the above alkaline storage batteries, in the method of manufacturing a rectangular alkaline storage battery, a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked via separators, and then the plurality of positive electrodes and the plurality of negative electrodes are welded to different current collectors. Thus, an electrode plate group is formed. At this time, if the welding is not sufficient, the battery characteristics are deteriorated. Therefore, it is necessary to determine whether the welding is sufficient when the welding is completed. Conventionally, in order to determine whether or not welding is possible, an inspection is usually performed visually after the end of welding.
[0004]
[Problems to be solved by the invention]
However, the above-described conventional method has a problem that it is difficult to make a judgment based on a certain judgment standard because the judgment is made by human eyes, and the productivity is poor. For this reason, the conventional method for manufacturing a prismatic alkaline storage battery has a problem that yield and productivity are not sufficient.
[0005]
In order to solve the above-described problems, an object of the present invention is to provide a method for manufacturing a prismatic alkaline storage battery with high yield and productivity by easily and accurately determining the quality of welding.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a method for producing a prismatic alkaline storage battery according to the present invention includes a plurality of positive electrodes and a plurality of negative electrodes alternately stacked via separators, and then the plurality of positive electrodes are first welded by a plurality of welds. The first step of welding to the current collector and welding the plurality of negative electrodes to the second current collector at a plurality of welds, and the first current collector and the second current collector. And a second step of determining whether the welding is good or not by measuring a resistance value between the plurality of welds. According to the above manufacturing method, it is possible to easily and accurately determine whether welding is good or bad, and therefore, a rectangular alkaline storage battery can be manufactured with high yield and productivity.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0008]
In the method for producing a prismatic alkaline storage battery of the present invention, first, a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked via a separator, and the plurality of positive electrodes and the plurality of negative electrodes are welded to current collectors, respectively (first Process). An example perspective view of the welding method at this time is shown in FIG.
[0009]
Referring to FIG. 1, positive electrode 11 is placed in a bag-like separator 12, and only lead portion 11a is exposed. A current collector 13 is disposed on the lead portions 11 a of the plurality of positive electrodes 11. A brazing material (not shown) is disposed on the back surface of the plurality of welded portions 13 (welded portions 13a to 13f), and the plurality of welded portions 13a to 13f are irradiated by irradiating the electron beams 16 to the welded portions 13a to 13f. The positive electrode 11 and the current collector 13 are welded at 13f. Similarly, the negative electrode 14 and the current collector 15 are welded. A sectional view of the electrode plate group 20 formed in this way is shown in FIG. Referring to FIG. 2, a plurality of positive electrodes 11 and a plurality of negative electrodes 14 are alternately stacked via separators 12 (hatching is omitted). The plurality of positive electrodes 11 are connected to a current collector (first current collector) 13. The plurality of negative electrodes 14 are connected to a current collector (second current collector) 15.
[0010]
Next, with respect to the electrode plate group 20 thus manufactured, the quality of welding is determined by measuring the resistance value between a plurality of welded portions for at least one selected from the current collector 13 and the current collector 15. (Second step). A front view of the measuring instrument 30 used at this time is shown in FIG. With reference to FIG. 3, the measuring instrument 30 includes an electrode plate group support portion 32 disposed on a stage 31 and an electrode terminal portion 33. The electrode plate group 20 arranged on the stage 31 is sandwiched between the electrode plate group support part 32 and the electrode terminal part 33. FIG. 4 shows a plan view of the electrode terminal portion 33 viewed from the electrode plate group 20 side. Referring to FIG. 4, electrode terminal portion 33 includes current terminals 34 a to 34 f and voltage terminals 35 a to 35 f at positions corresponding to weld portions 13 a to 13 f.
The current terminals 34a to 34f are connected to a direct current power source (not shown). The voltage terminals 34a to 34f are connected to a voltmeter (not shown). The current terminals 34 a to 34 f and the voltage terminals 35 a to 35 f are pressed against the welded portions 13 a to 13 f of the current collector 13 by a spring 36.
[0011]
Next, a method for determining the quality of welding will be specifically described. First, the electrode plate group 20 is set in the measuring instrument 30, and the current terminals 34a to 34f and the voltage terminals 35a to 35f are brought into close contact with the welded portions 13a to 13f. Thereafter, a constant current is passed through the current terminals 34a to 34f, and the voltage value between the voltage terminals 35a to 35f is measured. In addition, the voltage value may measure the voltage value between adjacent terminals, and may measure the voltage value between the terminal used as a reference | standard and another terminal.
[0012]
FIG. 5 schematically shows an equivalent circuit in the case where the distance between adjacent welds 13 is equal.
Referring to FIG. 5, between the welded portion 13a and a welding portion 13b adjacent the resistance R ₁₃ of the current collector 13 and _(ab), a resistor R _13a and resistor R _13b welds 13a and 13b, There is a resistance R _{11 (ab) of the} positive electrode 11. Here, for example, when a welding failure occurs in the welded portion 13a and the resistance _R13a increases, the voltage value at that portion increases. Even when the distance between the welds 13 adjacent the unequal, may be changed according to the R ₃₃ and R ₁₃ to the distance between the weld portion 13.
[0013]
Thus, the resistance value between terminals can be calculated from the voltage value between adjacent terminals or the voltage value between a reference terminal and another terminal. Then, the distance between the terminals and the resistance value are compared, and if there is a portion where the resistance value is higher than that between the other terminals, it can be seen that welding failure has occurred in that portion.
[0014]
After checking the welding failure about the positive electrode and the negative electrode as described above, the electrode plate group 20 having no welding failure is placed in the battery case, and the electrolyte is injected. Then, a rectangular alkaline storage battery can be manufactured by sealing a battery case.
[0015]
In addition, what is normally used for a square alkaline storage battery can be used for the positive electrode, negative electrode, separator, electrolyte solution, etc. which are used with the said manufacturing method. Specifically, nickel nickel foam filled with nickel hydroxide particles can be used for the positive electrode. Moreover, the punching metal with which the hydrogen storage alloy was apply | coated can be used for a negative electrode. Moreover, a sulfonated polypropylene separator can be used as the separator. Further, an alkaline aqueous solution containing potassium hydroxide as a solute can be used as the electrolytic solution.
[0016]
Although the embodiments of the present invention have been described above by way of examples, the present invention is not limited to the above-described embodiments, and can be applied to other embodiments based on the technical idea of the present invention.
[0017]
For example, the measuring instrument and the electrode plate group described in the above embodiment are examples, and a measuring instrument and an electrode plate group having other structures may be used.
[0018]
The current collector welding method described in the above embodiment is also an example, and other methods may be used for welding.
[0019]
【The invention's effect】
As described above, according to the method for manufacturing a prismatic alkaline storage battery of the present invention, it is possible to easily and accurately determine the quality of welding, so that the prismatic alkaline storage battery can be manufactured with high yield and productivity.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of an electrode plate group for a prismatic alkaline storage battery manufactured by the method for manufacturing a prismatic alkaline storage battery of the present invention.
2 is a cross-sectional view of the electrode plate group shown in FIG. 1. FIG.
FIG. 3 is a front view showing an example of a measuring instrument used in the method for manufacturing a prismatic alkaline storage battery of the present invention.
4 is a plan view showing a part of the measuring instrument shown in FIG. 3. FIG.
5 is a circuit diagram showing an equivalent circuit for the electrode plate group shown in FIG. 1. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Positive electrode 12 Separator 13, 15 Current collector 13a-13f Welding part 14 Negative electrode 16 Electron beam 20 Electrode board group 30 Measuring instrument 31 Stage 33 Electrode terminal part 34 Current terminal 35 Voltage terminal

Claims (1)

After alternately laminating a plurality of positive electrodes and a plurality of negative electrodes via separators, the plurality of positive electrodes are welded to the first current collector by a plurality of welds, and the plurality of negative electrodes are welded by a plurality of welds. A first step of welding to the two current collectors;
A second step of determining whether or not welding is good by measuring a resistance value between the plurality of welded portions with respect to at least one selected from the first current collector and the second current collector. A method for producing a prismatic alkaline storage battery.

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