JP2000268846A - Cylindrical storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical storage battery equipped with a spiral bunch of electrode plates and excellent in the output characteristics to enable taking- out of a large current. SOLUTION: A cylindrical storage battery is composed of a bunch 5 of electrode plates consisting of positive and a negative electrode plate and a separator which are wound round in spiral form, a positive electrode electricity collecting shoe 7 and a negative electrode electricity collecting shoe 8 consisting of flat plates welded to the forefront parts of the electrode plates protruding at the top and bottom of the bunch 5 of electrode plates, a case accommodating these together with an electrolytic solution, and a sealing plate to seal the case. The positive electrode shoe 7 and the negative electrode shoe 8 are provided with rectangular cutout parts ranging from the centers of the flat plates so as to straddle the peripheral edges in the radial arrangement at a constant spacing in a plurality of pieces between each other, and down-facing rib-form projections are formed rigidly at the edges of the cutout parts, wherein the rib-form projections on the positive electrode shoe 7 and those on the negative 8 are positioned diagonally to one another.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a cylindrical storage battery having a spirally formed electrode group.

[0002]

2. Description of the Related Art Cylindrical alkaline storage batteries such as nickel-cadmium storage batteries and nickel-hydrogen storage batteries are widely used as power sources for mobile phones and notebook computers because of their high reliability and easy maintenance. I have. Furthermore, in recent years, there has been an increasing demand for cylindrical alkaline storage batteries suitable for large-current discharge as a power source for electric tools, power assisted bicycles, electric vehicles, and the like.

[0003] A cylindrical alkaline storage battery is wound spirally between a strip-shaped positive electrode plate and a negative electrode plate with a separator interposed therebetween to form an electrode plate group, stored in a metal case together with an electrolytic solution, and sealed. It is formed by this.

Further, in an alkaline storage battery used for a large current discharge application, a positive electrode plate and a negative electrode plate are wound so that their upper end portions or lower end portions protrude from above and below the electrode plate group, respectively. The current collector from the electrode plate is enhanced by welding a rectangular or disk-shaped current collector to the tip of the negative electrode plate at a plurality of locations.

[0005]

However, such a current collector is welded to the electrode group by applying a welding electrode to the current collector and applying a current between the pair of electrodes while applying pressure. ing. In this case, the resistance value (reaction resistance) at the time of a large current discharge differs depending on the welding conditions of the current collector, which has caused a variation in output characteristics in mass production.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a strip-shaped positive electrode plate and a negative electrode plate comprising a separator, wherein one electrode plate has a tip end projecting upward and the other electrode plate having a tip end. A positive electrode made of a group of electrode plates whose parts protrude downward and are spirally wound, and a rectangular or substantially disk-shaped flat plate welded to each end of each electrode plate protruding from above and below the electrode group In a cylindrical storage battery including a current collector, a negative electrode current collector, a metal case containing an alkaline electrolyte therein, and a sealing plate having a cap-shaped terminal above and sealing the case, The current collector and the negative electrode current collector are provided with a plurality of rectangular cutout portions extending from near the center of the flat plate to the outer peripheral edge at equal intervals between the cutout portions and radially, and the edge portions of the cutout portions are provided. The downward rib-shaped protrusion The rib-shaped projections of the positive electrode current collector and the rib-shaped projections of the negative electrode current collector are welded to the tip portions of the respective electrode plates so that they are at diagonal positions to each other. It was assumed.

[0007]

DETAILED DESCRIPTION OF THE INVENTION According to the first aspect of the present invention, a strip-shaped positive electrode plate and a negative electrode plate are composed of a separator, the tip of one of the electrode plates protrudes upward, and the tip of the other electrode plate. A positive or negative electrode set consisting of a spirally wound electrode group protruding downward, and a rectangular or substantially disk-shaped flat plate welded to the tip of each of the electrode plates protruding from above and below the electrode group In a cylindrical storage battery comprising a metal case accommodating an electric conductor, a negative electrode current collector, and an alkaline electrolyte therein, and a sealing plate having a cap-shaped terminal above and sealing the case, The current collector and the negative electrode current collector are provided with a plurality of rectangular cutouts extending from near the center of the flat plate to the outer peripheral edge at equal intervals between the radial cutouts, and at the edges of the cutouts. Is a downward-facing rib-shaped projection Wherein the rib-shaped projections of the positive electrode current collector and the rib-shaped projections of the negative electrode current collector are welded to the tips of the respective electrode plates so that they are at diagonal positions to each other. It is.

[0008] By setting the welding positions of the rib-shaped projections of the positive electrode current collector and the negative electrode current collector on the electrode group to be diagonal to each other, the reaction resistance of the battery is reduced. Can be done.

This is because when the positions of the rib projections of the positive electrode current collector and the negative electrode current collector are diagonal, the current distribution during large current discharge is uniform on the electrode plate, and the reaction resistance of the active material is suppressed. It is thought that it is possible.

[0010]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples.
The present invention can be appropriately changed and implemented without changing the gist.

(Embodiment) FIG. 1 is a half-cut side view of a tabless nickel-hydrogen storage battery A according to an embodiment of the present invention. This battery A has a diameter of 33 mm and a height of 61.5 m.
m and a nominal capacity of 7000 mAh. This configuration will be described in detail below.

A sintered nickel positive electrode plate 1 having a thickness of 0.5 mm
And a coated hydrogen storage alloy negative electrode plate 2 having a thickness of 0.3 mm, and each of the electrode plates is provided with exposed core members 3 and 4 at its longitudinal end. , 4 are interposed so that the separator 6 is interposed so as to protrude above and below the electrode group 5 by about 1.5 mm, and the whole is spirally wound to form an electrode group having a diameter of about 30 mm and a height of about 50 mm. 5 was constructed.

Immediately above the upper end face of the electrode plate group 5, a rectangular current collector 7 having a through hole in the center and having a diagonal length of about 27 mm is disposed, and an exposed core is formed using a pair of welding electrodes. It was welded to the material part 3 at a plurality of locations. FIG. 2 shows a top view of the current collector 7.

The current collector 7 is a flat plate portion 7 having a thickness of 0.4 mm and radially provided with rectangular cutout portions 7a reaching the outer peripheral circle from near the center thereof at equal intervals between four locations.
and the exposed core material portion 3 of the positive electrode plate 1 is integrally provided by being bent downward at opposite edge portions 7c of the cutout portions 7a.
And a rib-shaped projection 7d which is welded crosswise. FIG. 3 shows a front view.

Next, a rectangular current collector 8 having the same diagonal length as described above, provided with a tongue piece for welding at the center on the lower end face of the electrode plate group 5, is shown in FIG. As shown in the figure, the current collector 7 was arranged so as to be diagonal to the welding position of the rib-shaped projection pieces, and was welded to the exposed core 4 at a plurality of locations using a pair of welding electrodes. .

This electrode plate group 5 is inserted into a metal case 9,
The tongue provided at the center of the current collector 8 was pressed through one welding electrode through the central through-hole of the current collector 7, and the pressed portion was welded to the inner bottom surface of the battery case.

Next, after injecting a predetermined amount of alkaline electrolyte into the battery case 9, the connection lead provided on the current collector 7 is
The sealing plate 1 is welded to the lower surface of the sealing plate 11 also serving as the positive electrode terminal.
1, the opening of the case 9 is sealed, and the battery A of the present invention is
Cell created.

(Comparative Example 1) For comparison, the welding positions of the rib-shaped projections of the current collector 7 and the current collector 8 with respect to the electrode plate group 5 were mutually set as shown in the schematic diagram of FIG. Fifty cells of battery B were prepared in the same manner as in the above example except that welding was performed so as to define parallel positions. (Comparative Example 2) Further, for comparison, the above-described operation was performed except that the welding positions of the rib-shaped projection pieces of the current collector 7 and the current collector 8 were welded (randomly) to the electrode group 5 without any particular limitation. Fifty cells of battery C were prepared in the same manner as in the example.

In each of these batteries A, B, and C,
After charging at a current value of 0.7 A for 15 hours, the battery was initially charged and discharged by discharging at a current value of 7 A until the battery voltage reached 1.0 V. The battery after the first charge / discharge is 1.5 h at a current value of 7 A
After charging, the battery was initially activated by repeating charge / discharge at a current value of 7 A to 1.0 V for 10 cycles, thereby performing initial activation of the battery.

The output characteristics of these batteries after initial activation were evaluated by the following method.

The battery is charged at a current value of 7 A for 0.4 hours,
After leaving for 0.5 hour, the battery was discharged for 10 seconds at a current value of 50 A, and the battery voltage at 10 seconds was read. The output characteristics were evaluated using this voltage value, and it was determined that the higher the voltage value, the better the output characteristics.

FIG. 6 shows the evaluation results of the output characteristics of the batteries A, B, and C. Battery A, in which the welding positions of the rib-shaped protrusions of the positive electrode current collector 7 and the negative electrode current collector 8 are defined at diagonal positions, has an average value of the discharge voltage per 50 cells of the battery compared to the batteries B and C. It can be seen that the variation is reduced as compared with the battery C in which the welding position of the current collector is not specified.

The current collector has a rectangular shape as shown in FIG. 2 and, in addition to a rectangular shape as shown in FIG. 2, a flat plate portion 7b as shown in a top view in FIG. Almost the same effect can be obtained by using a substantially disk-shaped member.

In the above embodiment, a nickel-hydrogen storage battery is shown as a cylindrical storage battery, but other cylindrical storage batteries such as a nickel-cadmium storage battery and a lithium ion secondary battery can be similarly applied.

[0025]

As described above, according to the present invention, it is possible to provide a cylindrical rechargeable battery having a spirally-shaped electrode plate group and capable of extracting a large current and having excellent output characteristics.

[Brief description of the drawings]

FIG. 1 is a half-cut side view of a nickel-hydrogen storage battery A according to an embodiment of the present invention.

FIG. 2 is a top view of the current collector 7;

FIG. 3 is a front view of the current collector 7;

FIG. 4 is a schematic diagram showing a positional relationship between the current collector 7 and the current collector 8;

FIG. 5 is a schematic diagram showing a positional relationship between a current collector 7 and a current collector 8 in Comparative Example 1.

FIG. 6 is a diagram showing evaluation results of output characteristics of batteries A, B, and C.

FIG. 7 is a top view of a substantially disk-shaped current collector;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode plate 2 Negative electrode plate 3 Exposed core material part of positive electrode plate 4 Exposed core material part of negative electrode plate 5 Electrode group 6 Separator 7 Current collector of positive electrode 8 Current collector of negative electrode 9 Case 10 Connection terminal 11 Sealing plate

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Takuma Iida 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. Terms (reference) 5H022 AA04 BB02 BB11 CC02 CC12 CC27 5H028 AA05 AA06 AA07 BB05 CC07 CC08 CC10 CC12 EE01

Claims (2)

[Claims] 1. A spirally wound electrode plate comprising a strip-shaped positive electrode plate and a negative electrode plate comprising a separator, the tip of one electrode plate protruding upward, and the tip of the other electrode plate protruding downward. Group, a positive electrode current collector and a negative electrode current collector consisting of a rectangular or substantially disk-shaped flat plate welded to the respective tips of the respective electrode plates protruding from above and below the electrode plate group, and an alkaline electrolyte. In a cylindrical storage battery comprising a metal case housed therein and a sealing plate provided with a cap-shaped terminal at the top while sealing the case, the positive electrode current collector and the negative electrode current collector are formed at the center of the flat plate. A plurality of rectangular cutouts straddling the outer peripheral edge from near and radially provided at equal intervals between the cutouts, and downwardly extending rib-like protrusions are integrally formed at the edges of the cutouts. And a rib of the positive electrode current collector Cylindrical battery rib-like projection piece projecting piece and the anode current collector to each other is welded to the distal end portion of each of the electrode plate such that the position of the diagonal. 2. The cylindrical storage battery according to claim 1, wherein the cores of the positive electrode plate and the negative electrode plate are exposed at the tip portions protruding upward and downward of the electrode plate group.