JP4656802B2 - Alkaline storage battery - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an alkaline storage battery, and in particular, after a positive current collector plate is joined to a power generation element, the positive electrode current collector plate is accommodated in a battery case. Relates to an alkaline storage battery.
[0002]
[Prior art]
Alkaline storage batteries such as nickel metal hydride batteries and nickel cadmium batteries are used in a wide range of applications, from small ones as power sources for portable electric devices to large ones as power sources for hybrid electric vehicles (HEV). And since the electrical load increased with the expansion of the function of the device, further improvement in the high rate discharge characteristic (which can be paraphrased as output characteristic) is required for the battery.
[0003]
As shown in FIG. 5, a conventional alkaline storage battery 70 has a power generation element 71 formed by winding a negative electrode 73 and a positive electrode 74 with a separator 72 interposed therebetween, and the negative electrode 73 exposed from the separator 72 on the lower end side of the power generation element 71. A negative current collector plate 80 is joined to the end 75 of the power generation element, and a positive current collector 81 is joined to the end 76 of the positive electrode 74 exposed from the separator 72 on the upper end side of the power generation element 71. The electric plate 80 and the positive electrode current collecting plate 81 are accommodated in a bottomed cylindrical battery case 85, and the battery case 85 is closed by a lid portion 86.
[0004]
As shown in FIG. 6, the lead part 82 is extended in the substantially U shape from the periphery of the positive electrode current collecting plate 81, and the tip 83 of the lead part 82 is joined to the lid part 86 (see FIG. 5). As a result, the lid portion 86 is electrically connected to the positive electrode current collector plate 81 via the lead portion 82.
However, if the lid portion 86 is electrically connected to the positive electrode current collector plate 81 via the lead portion 82, the current path becomes longer, which increases resistance and hinders increase in output.
[0005]
On the other hand, a lead portion 90 shown in FIG. 7 has been proposed as another means for electrically connecting the lid portion 86 to the positive electrode current collector plate 81. The lower end 93 of the lead part 90 is joined to the positive electrode current collector 91, and the protrusion 94A formed on the upper end 94 of the lead part 90 is joined to the lid part 86, whereby the lid part 86 is connected to the positive electrode current collector via the lead part 90. It can be electrically connected to the plate 91.
By joining the lower end 93 of the lead part 90 to the positive electrode current collector 91, the current path can be shortened as compared with the lead part 81 shown in FIG. 6, so that the resistance can be reduced and the output can be increased.
[0006]
[Problems to be solved by the invention]
However, since the lead part 90 shown in FIG. 7 is a separate member from the positive electrode current collector 91, two parts of the positive electrode current collector 91 and the lead part 90 are required, and the number of parts increases.
In addition, it is necessary to join the lower end 93 of the lead part 90 to the positive electrode current collector 91, which increases the joining process. Thus, since the number of parts and the joining process increase, it is difficult to suppress the cost.
[0007]
The present invention has been made in view of the above-described problems, and an object thereof is to provide an alkaline storage battery that can shorten the current path to improve the high-rate discharge characteristics of the battery and reduce the number of parts. There is.
[0008]
To achieve the above object, the present invention includes a power generating element that turns of the negative electrode and the positive electrode via the separator, for the negative electrode core material exposed portions on the both end surfaces and the positive electrode core member exposed portions of the power generating element A negative electrode current collector plate and a positive electrode current collector plate joined by electric resistance welding, laser welding or beam welding , and a bottomed cylindrical battery case for housing the power generation element, the negative electrode current collector plate and the positive electrode current collector plate; An alkaline storage battery comprising a lid for closing the battery case and a safety valve provided outside the battery case of the lid, wherein the positive current collector plate is integrally formed to protrude toward the lid by having a positive electrode side protruding part, before SL to the positive electrode side protruding portion is bonded to the inner battery casing inner surface of a surface of said lid portion, wherein the inner battery casing inner surface of the surface of the lid portion The joining point of the positive electrode side protruding portion is the outside of the battery case of the lid portion. It is present outside the region corresponding to the region where the safety valve is in contact in the plane, and wherein the positive electrode side protruding portion is substantially cylindrical along the central axis of the positive electrode current collector plate.
[0009]
By projecting the projecting portion from one of the positive electrode current collector plate and the lid portion toward the other, the projecting portion can be arranged to pass the shortest distance between the positive electrode current collector plate and the lid portion.
Therefore, the current path can be shortened to reduce the resistance.
[0010]
In addition, the number of parts can be reduced by integrally forming the protruding part on one of the positive electrode current collector plate and the lid part, and the joining process can be reduced by reducing the number of parts.
[0011]
In the present invention, it is preferable prior Symbol positive electrode side protruding portion is substantially cylindrical along the central axis of definitive to the positive electrode current collector plate.
[0012]
By making the protrusion a substantially cylindrical shape along the central axis of one of the positive electrode current collector plate and the lid, the length of the current collecting path becomes uniform, and positioning of the welded part during welding becomes easy. In addition, the pressure resistance when the parts to be welded at the time of welding are brought into contact with each other is high and hardly deformed.
[0013]
Further, in the present invention, since a plurality of slits extending radially from the center before Symbol positive electrode side protruding portion is formed, to reduce the reactive current when performing the electric resistance welding, the thickness of the current collector terminal is thick But good welding is possible.
Further, even if the current collecting terminal is thick, drawing is easy.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. In the embodiments described below, the members and the like already described in FIGS. 1 to 2 are denoted by the same or corresponding reference numerals in the drawings, and the description is simplified or omitted.
[0015]
As shown in FIG. 1, the alkaline storage battery 10 of the first embodiment includes a power generation element 11 in which a negative electrode 13 and a positive electrode 14 are wound via a separator 12, and both end faces 11A and 11B of the power generation element 11, that is, a negative electrode 13. The negative electrode current collector plate 21 and the positive electrode current collector plate 21 joined to the negative electrode core material exposed portion 15 and the positive electrode core material exposed portion 16 of the positive electrode 14 by electric resistance welding such as spot welding, laser welding, beam welding or the like. A bottomed cylindrical battery case 25 that houses the power generation element 11, the negative electrode current collector plate 20, and the positive electrode current collector plate 21, and a lid portion 26 that closes the battery case 25.
The lid portion 26 is provided with a safety valve 28 with a cap 27.
[0016]
As shown in FIGS. 1 and 2, the positive electrode current collector plate 21 has a substantially cylindrical positive electrode side protrusion (protrusion) extending toward the lid 26 along the central axis C <b> 1 of the positive electrode current collector 21. ), An opening 23A is formed at the end of the positive electrode side protruding portion 22, that is, a joint end surface 23 with the lid portion 26 of the positive electrode current collector plate 21, and, for example, four protrusions 24 are formed around the opening 23A. Yes.
The positive electrode side protruding portion 22 is formed with a plurality of slits 22A extending radially from the center. Each of these slits 22A is formed at a position corresponding to each projection 24.
The positive electrode side protruding portion 22 is integrally formed with the positive electrode current collector plate 21 by drawing as an example. For this reason, the positive electrode side protruding portion 22 can be easily formed on the positive electrode current collector plate 21.
[0017]
The positive electrode current collector 21 is a member formed of a conductive material such as nickel or a nickel-plated steel plate (cold-rolled steel plate SPCC), but is not limited thereto.
Further, the positive electrode current collector plate 21 is set to have a plate thickness t1 of 0.2 to 0.5 mm.
[0018]
If the plate thickness t1 is less than 0.2 mm, there is a drawback that the electric resistance is high. Further, a sufficient contact pressure cannot be obtained in the welding with the lid portion 26, and it is difficult to perform the welding. On the other hand, if the plate thickness t1 exceeds 0.5 mm, the difference in heat capacity with the base of the electrode plate becomes large, so that it becomes difficult to weld the electrode plate to the substrate.
Therefore, the plate thickness t1 of the positive electrode current collector plate 21 was set to 0.2 to 0.5 mm.
[0019]
The lid portion 26 has a substantially cylindrical lid-side protruding portion (protruding portion) 30 extending toward the positive electrode current collector plate 21 along the central axis C 1 of the lid portion 26.
The lid-side protruding portion 30 is formed such that the outer peripheral wall 31 is formed in an annular shape, the inner side surface 32 of the outer peripheral wall 31 is formed to be flush with the outer peripheral portion 33 of the lid portion 26, and an opening 32A is formed at the center of the inner side surface 32. Is formed. The opening 32A is closed by a safety valve 28.
[0020]
As an example, the lid-side protruding portion 30 is integrally formed with the lid portion 26 by drawing. Therefore, the lid-side protrusion 30 can be easily formed on the lid 26.
The lid portion 26 is a member formed of a conductive material such as nickel or a nickel-plated steel plate (SPCC), but is not limited thereto.
[0021]
The lid portion 26 has a plate thickness t2 set to 0.8 to 1.5 mm.
If the plate thickness t2 is less than 0.8 mm, it is difficult to ensure the strength to withstand the internal pressure of the battery. On the other hand, if the plate thickness t2 exceeds 1.5 mm, it is difficult to draw and seal the battery. Therefore, the plate thickness t2 of the lid portion 26 is set to 0.8 to 1.5 mm.
[0022]
By joining the protrusion 24 of the positive electrode side protruding portion 22 to the tip 31A of the outer peripheral wall 31 of the cover side protruding portion 30, the cover portion 26 is connected to the positive electrode collection via the positive electrode side protruding portion 22 and the cover side protruding portion 30. It is electrically connected to the electric plate 21.
[0023]
In this way, the positive electrode side protruding portion 22 on the positive electrode current collector plate 21 side is extended toward the lid portion 26, and the lid side protruding portion 30 on the lid portion 26 side is extended toward the positive electrode current collector plate 21, thereby The protrusion 24 provided on the joining end face 23 of the positive electrode side protruding portion 22 is joined to the tip 31A of the outer peripheral wall 31 of the portion 30.
[0024]
Therefore, the outer peripheral wall 31 of the positive electrode side protruding portion 22 and the lid side protruding portion 30 can be disposed so as to pass the shortest distance between the positive electrode current collector plate 21 and the cover portion 26. Thereby, since the current path can be shortened, the resistance can be reduced and the output can be increased.
[0025]
Further, the positive electrode side protruding portion 22 is integrally formed with the positive electrode current collector plate 21 and the outer peripheral wall 31 of the cover side protruding portion 27 is integrally formed with the cover portion 26, so that the cover portion and the positive electrode collector are collected as in the conventional battery. The number of parts can be reduced compared to the case where the electric plate is connected via the lead, and the lid portion and the positive electrode current collecting terminal are directly joined to reduce the number of joints to one place. At the same time, the electrical resistance between the lid and the positive electrode current collector terminal can be reduced.
[0026]
Further, the positive electrode side protruding portion 22 is formed in a substantially cylindrical shape along the central axis C1, and the outer peripheral wall 31 of the lid side protruding portion 30 is formed in a substantially cylindrical shape along the central axis C1.
Accordingly, there is an advantage that parts to be welded can be reliably brought into contact with each other during welding and positioning can be easily performed.
[0027]
In addition, the plurality of slits 22A formed in the positive electrode-side protruding portion 22 reduces the reactive current when resistance welding is performed, and enables good welding even when the positive electrode current collector plate 21 is thick. Drawing is easy even if the electric plate 21 is thick. In addition, since the protrusion 24 provided on the joining end face 23 melts quickly during welding, good joining can be achieved even if the contact pressure between the lid and the positive electrode current collector plate is reduced. This is effective in preventing the part from being deformed. The shape of the protrusion is not particularly limited, and a linear protrusion extending in a ring shape can be applied in addition to the dot-like protrusion shown in FIG.
[0028]
Next, a form of a reference example and another embodiment of the present invention will be described based on FIG. 3 and FIG.
The alkaline storage battery 40 of the reference example shown in FIG. 3 is the alkaline storage battery of the first embodiment in that a positive current collector 41 and a lid 42 are employed instead of the positive current collector 21 and the lid 26 of the first embodiment. The other members are the same as those of the first embodiment, except for the difference from 10.
[0029]
In the positive current collector 41, an opening 41A is formed at the center of the positive current collector 41, and, for example, four protrusions 43 are formed around the opening 41A.
The positive electrode current collector 41 is a member formed of a conductive material such as nickel or a nickel-plated steel plate (SPCC), but is not limited thereto.
[0030]
The lid portion 42 has a substantially cylindrical lid-side protrusion (protrusion portion) 44 extending toward the positive electrode current collector plate 41 along the central axis C1 of the lid portion 42. The lid-side protruding portion 44 has an outer peripheral wall 45 formed in an annular shape, an inner side surface 46 of the outer peripheral wall 45 is formed so as to be flush with the outer peripheral portion 47 of the lid portion 42, and an opening 46A is formed at the center of the inner side surface 46. Is formed. The opening 46A is closed by a safety valve 28.
[0031]
As an example, the lid-side protruding portion 44 is integrally formed with the lid portion 42 by drawing. For this reason, the lid-side protrusion 44 can be easily formed on the lid 42.
The lid 42 is a member formed of a conductive material such as nickel or a nickel-plated steel plate (SPCC), for example, but is not limited thereto.
[0032]
Further, the lid portion 42 has a plate thickness t3 set to 0.8 to 1.5 mm.
If the plate thickness t3 is less than 0.8 mm, it is difficult to ensure the strength to withstand the internal pressure of the battery. On the other hand, if the plate thickness t3 exceeds 1.5 mm, it is difficult to draw and seal the battery. Therefore, the plate thickness t3 of the lid portion 26 is set to 0.8 to 1.5 mm.
[0033]
The lid-side protruding portion 44 on the lid portion 42 side is extended toward the positive electrode current collecting plate 41, and the protrusion 43 of the positive electrode current collecting portion 41 is joined to the tip 45A of the outer peripheral wall 45 of the lid protruding portion 44. Was configured to be electrically connected to the positive electrode current collector plate 41.
[0034]
Therefore, the outer peripheral wall 45 of the lid-side protrusion 44 can be disposed so as to pass the shortest distance between the positive electrode current collector 41 and the lid 42. Thereby, since the current path can be shortened, the resistance can be reduced and the output can be increased.
Further, by integrally molding the outer peripheral wall 45 of the lid-side protrusion 44 with the lid 42, the number of parts can be reduced, and in addition, the joining process can be reduced.
[0035]
Furthermore, by forming the outer peripheral wall 45 of the lid-side protruding portion 44 in a substantially cylindrical shape along the central axis C1, the length of the current collecting path is made uniform, and the position of the welded part during welding is easy. In addition, there is an advantage that the pressure resistance when the parts to be welded at the time of welding are brought into contact with each other is high and deformation is difficult.
[0036]
An alkaline storage battery 50 according to another embodiment of the present invention shown in FIG. 4 is the first in that a positive current collector 51 and a lid 52 are employed instead of the positive current collector 21 and the lid 26 of the first embodiment. Other than the alkaline storage battery 10 of the embodiment, the other members are the same as in the first embodiment.
[0037]
The positive electrode current collecting plate 51 has a substantially cylindrical positive electrode side protruding portion (protruding portion) 53 extending toward the lid portion 52 along the central axis C 1 of the positive electrode current collecting plate 51. An opening 54A is formed at the center of the tip 54 of the positive electrode side protruding portion 53, and for example, four protrusions 55 are formed around the opening 54A.
[0038]
The positive electrode side protruding portion 53 is integrally formed with the positive electrode current collector plate 51 by drawing as an example. For this reason, the positive electrode side protruding portion 53 can be easily formed on the positive electrode current collector plate 51.
The positive electrode current collecting plate 51 is a member formed of a conductive material such as nickel or a nickel-plated steel plate (SPCC), but is not limited thereto.
[0039]
Further, the positive electrode current collecting plate 51 has a plate thickness t4 set to 0.2 to 0.5 mm.
If the plate thickness t4 is less than 0.2 mm, there is a drawback that the electric resistance is high. Further, a sufficient contact pressure cannot be obtained in the welding with the lid portion 26, and it is difficult to perform the welding. On the other hand, if the plate thickness t4 exceeds 0.5 mm, the difference in heat capacity between the electrode plate and the substrate becomes large, so that it becomes difficult to weld the electrode plate to the substrate.
Therefore, the plate thickness t4 of the positive electrode current collector plate 21 was set to 0.2 to 0.5 mm.
[0040]
An opening 52A is formed in the center of the lid 52, and the opening 52A is closed by a safety valve 28.
The lid 52 is a member formed of a conductive material such as nickel or a nickel-plated steel plate (SPCC), but is not limited thereto.
[0041]
By extending the positive electrode side protruding portion 53 of the positive electrode current collector plate side 51 toward the lid portion 52 and joining the protrusion 55 formed on the tip 54 of the positive electrode side protruding portion 53 to the lid portion 52, the lid portion 52 is The electric plate 51 is configured to be electrically connected.
[0042]
Therefore, the positive electrode side protruding portion 53 can be arranged so as to pass the shortest distance between the positive electrode current collecting plate 51 and the lid portion 52. Thereby, since the current path can be shortened, the resistance can be reduced and the output can be increased.
Further, by integrally forming the positive electrode side protruding portion 53 on the positive electrode current collector plate 51, it is possible to reduce the number of parts and to reduce the joining process.
[0043]
Further, by forming the positive electrode side protruding portion 53 in a substantially cylindrical shape along the central axis C1, the length of the current collecting path becomes uniform, and the positioning of the welded portion during welding becomes easy, and There is an advantage that the pressure resistance when the parts to be welded at the time of welding are brought into contact with each other is high and deformation is difficult.
[0044]
The present invention is not limited to the above-described embodiment, and appropriate modifications, improvements, and the like are possible. The power generation element, the positive electrode current collector plate, the lid, and the positive electrode side protrusion illustrated in the above-described embodiment. The material, shape, dimension, form, number, arrangement location, thickness dimension, etc. of the part, lid-side protruding part, etc. are arbitrary and not limited as long as the present invention can be achieved.
[0045]
【The invention's effect】
As described above, according to the present invention, by projecting the collision detecting section towards either et lid positive electrode current collector plate, a positive electrode current collector plate and protrusions to pass the shortest distance between the cover portion Can be placed.
Therefore, since the current path can be shortened, the output characteristic of the battery can be improved by reducing the resistance.
[0046]
In addition, the number of parts can be reduced by integrally forming the protruding part on one of the positive electrode current collector plate and the lid part, and the joining process can be reduced by reducing the number of parts.
Thus, since the number of parts and the joining process can be reduced, the cost can be suppressed.
[0047]
According to the present invention, by providing a projection on junction end face, since the contact pressure of both when welding the lid portion and the positive electrode current collector terminal can be reduced, it is effective to prevent deformation of the projecting portion .
[0048]
Further, according to the present invention, by a substantially cylindrical shape along the central axis of one of the collision detection section positive electrode current collector plate and lid, with the length of the current collecting paths is equalized, during welding Positioning of the welded part is facilitated, and the pressure resistance when the parts to be welded at the time of welding are brought into contact with each other is high, so that deformation is difficult.
[0049]
Then, according to the present invention, since a plurality of slits extending radially from the center to the collision detecting portion is formed, the reactive current when performing resistance welding to reduce, even thicker wall thickness of the current collector terminals good Can be easily welded and drawing is easy.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a first embodiment of an alkaline storage battery according to the present invention.
FIG. 2 is an exploded perspective view showing a main part of the first embodiment according to the present invention.
FIG. 3 is a cross-sectional view of an alkaline storage battery of a reference example .
FIG. 4 is a cross-sectional view showing another embodiment of the alkaline storage battery according to the present invention.
FIG. 5 is a cross-sectional view showing a conventional alkaline storage battery.
FIG. 6 is a perspective view showing a main part of a conventional alkaline storage battery.
FIG. 7 is a perspective view showing another example of a conventional alkaline storage battery.
[Explanation of symbols]
10,40,50 alkaline storage battery
11 Power generation elements
11A, 11B Power generation element end faces
12 Separator
13 Negative electrode
14 Positive electrode
15 Negative electrode core material
16 Positive electrode core material
17 Negative electrode core exposed part
18 Positive electrode core exposed part
20 Negative current collector
21,41,51 Positive current collector
23 Joint end face
24 protrusions
26,42,52 Lid
22,53 Positive side protrusion (protrusion)
30,44 Cover side protrusion (protrusion)
C1 center axis

Claims (3)

A power generating element that turns of the negative electrode and the positive electrode via a separator, electrical resistance welding for the negative electrode core material exposed portions on the both end surfaces and the positive electrode core member exposed portions of the power generating element, which is joined by laser welding or beam welding A negative electrode current collector plate and a positive electrode current collector plate, a bottomed cylindrical battery case for housing the power generation element, the negative electrode current collector plate and the positive electrode current collector plate, a lid portion for closing the battery case, and the lid an alkaline storage battery comprising a safety valve provided outside the container parts, the positive electrode current collector plate has a positive electrode side protruding portion integrally formed to project toward the lid, before Kiseikyoku The side protruding portion is bonded to the inner surface of the lid portion of the surface of the lid portion, and the bonding portion of the positive side protruding portion on the inner surface of the lid portion of the surface of the lid portion is the position of the lid portion. Area where the safety valve is in contact with the outer surface of the battery case Corresponding to exist outside the region, and alkaline storage battery wherein the positive electrode side protruding portion is substantially cylindrical along the central axis of the positive electrode current collector plate.   The alkaline storage battery according to claim 1, wherein a plurality of slits extending radially from the center are formed in the positive electrode side protruding portion.   The alkaline storage battery according to claim 1, wherein the lid portion includes a lid-side protruding portion that protrudes toward the positive electrode current collector plate.

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