JP2004063231A - Alkaline storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alkaline storage battery in which a current route can be shortened and the number of components can be reduced. <P>SOLUTION: The alkaline storage battery 10 comprises a negative electrode current collector plate 20 and a positive electrode current collector plate 21 jointed to either side end of a generating element 11, a battery case 25 that houses the generating element 11, the negative electrode current collector plate 20, and the positive electrode current collector plate 21, and a lid part 26 that closes the battery case 25. The alkaline storage battery 10 has a positive electrode side protrusion 22 that protrudes from the positive electrode current collector plate 21 toward the lid part 26 by being molded in one body and a lid part side protrusion 30 that protrudes from the lid part 26 toward the positive electrode current collector plate 21 by being molded in one body, and the positive electrode current collector plate 21 and the lid part 26 are jointed through each protrusion 22, 30. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an alkaline storage battery, in particular, after joining a positive electrode current collector to a power generating element, housing the battery in a battery case, closing the opening of the battery case with a lid, and electrically connecting the positive current collector to the lid. And a related 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 batteries for portable electric devices to large batteries for hybrid electric vehicles (HEV). Since the electrical load has increased with the expansion of the function of the device, further improvement in the high-rate discharge characteristics (which can be rephrased as output characteristics) has been required for batteries.
[0003]
As shown in FIG. 5, a conventional alkaline storage battery 70 has a power generating 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 at the lower end of the power generating element 71. A negative electrode current collector 80 is joined to the end 75 of the positive electrode, and a positive electrode 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 generating element 71. The electric plate 80 and the positive electrode current collecting plate 81 are accommodated in a bottomed cylindrical electric container 85, and the electric container 85 is closed by a lid 86.
[0004]
As shown in FIG. 6, a lead portion 82 extends in a substantially U shape from the periphery of the positive electrode current collector plate 81, and a tip 83 of the lead portion 82 is joined to a lid portion 86 (see FIG. 5). As a result, the lid 86 is electrically connected to the positive electrode current collector 81 via the lead 82.
However, when the lid 86 is electrically connected to the positive electrode current collector 81 via the lead 82, the current path becomes longer, so that the resistance increases and the output is hindered.
[0005]
On the other hand, as another means for electrically connecting the lid 86 to the positive electrode current collector 81, a lead 90 shown in FIG. 7 has been proposed. The lower end 93 of the lead portion 90 is joined to the positive electrode current collector plate 91 and the projection 94A formed on the upper end 94 of the lead portion 90 is joined to the lid portion 86. It can be electrically connected to the plate 91.
By joining the lower end 93 of the lead portion 90 to the positive electrode current collector 91, the current path can be shortened as compared with the lead portion 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 portion 90 shown in FIG. 7 is a separate member from the positive electrode current collector 91, two components, the positive electrode current collector 91 and the lead portion 90, are required, and the number of components is increased.
In addition, it is necessary to join the lower end 93 of the lead portion 90 to the positive electrode current collector 91, which increases the number of joining steps. As described above, since the number of components and the number of joining steps increase, it is difficult to reduce costs.
[0007]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an alkaline storage battery capable of shortening a current path to improve high-rate discharge characteristics of the battery and reducing the number of components. It is in.
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention provides a power generating element in which a negative electrode and a positive electrode are wound with a separator interposed therebetween, and the core material from both ends of the power generating element. Negative electrode current collector plate and positive electrode current collector plate joined by electric resistance welding, laser welding, or beam welding to the exposed negative electrode core material exposed portion and positive electrode core material exposed portion, and the power generation element and the negative electrode current collector plate And a bottomed cylindrical battery case that houses the positive electrode current collector plate, and an alkaline storage battery including a lid portion that closes the battery case, wherein the alkaline storage battery includes one of the positive electrode current collector plate and the lid portion. It has a protruding portion integrally formed and protruding toward the other side, wherein the positive electrode current collector plate and the lid are joined via the protruding portion.
[0009]
By projecting the projection from one of the positive electrode current collector plate and the lid toward the other, the projection can be arranged so as to pass the shortest distance between the positive electrode current collector and the lid. Therefore, the resistance can be reduced by shortening the current path.
[0010]
In addition, the number of components can be reduced by integrally forming the protruding portion on one of the positive electrode current collector plate and the lid, and the number of components can be reduced, thereby reducing the number of joining steps.
[0011]
Further, in the present invention, as described in claim 2, the protrusion is substantially cylindrical along a central axis of one of the positive electrode current collector plate and the lid.
[0012]
By making the protruding part 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 the positioning of the welded part during welding becomes easy. In addition, when the parts to be welded are brought into contact with each other during welding, the pressure resistance is high and the parts are not easily deformed.
[0013]
Further, in the present invention, as described in claim 3, since a plurality of slits extending radially from the center are formed in the protruding portion, a reactive current when performing electric resistance welding is reduced, and current collection is performed. Good welding can be performed even if the terminal is thick.
Further, even if the thickness of the current collecting terminal is large, the drawing process is easy.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. In the embodiment described below, the members and the like already described in FIGS. 1 and 2 are denoted by the same reference numerals or corresponding reference numerals in the drawings to simplify or omit the description.
[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 with a separator 12 interposed therebetween, and both end surfaces 11A and 11B of the power generation element 11, that is, the negative electrode 13 A negative electrode current collector plate 20 and a positive electrode current collector plate 21 joined to the negative electrode core exposed portion 15 and the positive electrode core exposed portion 16 of the positive electrode 14 by electric resistance welding such as spot welding, laser welding, beam welding, or the like. And a bottomed cylindrical battery case 25 that houses the power generating element 11, the negative electrode current collecting plate 20 and the positive electrode current collecting plate 21, and a lid 26 that closes the battery case 25.
The lid 26 is provided with a safety valve 28 by a cap 27.
[0016]
As shown in FIGS. 1 and 2, a substantially cylindrical positive-electrode-side protruding portion (protruding portion) extending toward the lid portion 26 along the central axis C1 of the positive current collecting plate 21 is provided on the positive current collecting plate 21. An opening 23A is formed at the tip of the positive electrode side protruding portion 22, that is, at the joint end surface 23 of the positive electrode current collector plate 21 with the lid portion 26, and, for example, four projections 24 are formed around the opening 23A. I have. The positive electrode-side protruding portion 22 is formed with four slits 22A extending radially from the center. These slits 22 </ b> A are formed at positions corresponding to between the projections 24.
The positive electrode side protruding portion 22 is integrally formed with the positive electrode current collector plate 21 by drawing, for example. Therefore, 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 plate 21 is a member formed of a material having conductivity, such as nickel or a nickel-plated steel plate (a cold-rolled steel plate SPCC), but is not limited thereto.
The thickness t1 of the positive electrode current collector plate 21 is set to 0.2 to 0.5 mm.
[0018]
If the plate thickness t1 is less than 0.2 mm, there is a disadvantage that the electric resistance is high. Further, sufficient contact pressure cannot be obtained in welding with the lid portion 26, and it is difficult to perform welding. On the other hand, when the plate thickness t1 exceeds 0.5 mm, the difference in heat capacity between the electrode plate and the base increases, 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 is 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 C1 of the lid portion 26.
The lid-side protruding portion 30 has an outer peripheral wall 31 formed in an annular shape, an inner side surface 32 of the outer peripheral wall 31 is formed so as to be flush with an outer peripheral portion 33 of the lid portion 26, and an opening 32 </ b> A is formed at the center of the inner side surface 32. Is formed. The opening 32A is closed by a safety valve 28.
[0020]
The lid-side protruding part 30 is integrally formed with the lid part 26 by, for example, drawing. Therefore, the lid-side protrusion 30 can be easily formed on the lid 26.
The lid 26 is a member formed of a conductive material such as nickel or a nickel-plated steel plate (SPCC), but is not limited to this.
[0021]
Further, the thickness of the cover 26 is set to 0.8 to 1.5 mm.
If the plate thickness t2 is less than 0.8 mm, it is difficult to secure strength enough to withstand the internal pressure of the battery. On the other hand, when 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 26 is set to 0.8 to 1.5 mm.
[0022]
The protrusion 24 of the positive electrode side protruding portion 22 is joined to the tip 31A of the outer peripheral wall 31 of the lid side protruding portion 30, so that the lid portion 26 is connected to the positive electrode collection via the positive side protruding portion 22 and the lid side protruding portion 30. It is electrically connected to the electric plate 21.
[0023]
As described above, the positive-side projecting 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 current collector plate 21. The protrusion 24 provided on the joining end surface 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 part 22 and the lid side protruding part 30 can be arranged so as to pass through the shortest distance between the positive electrode current collector plate 21 and the lid part 26. As a result, the current path can be shortened, so that the resistance can be reduced and the output can be increased.
[0025]
Also, by forming the positive side projection 22 integrally with the positive electrode current collector plate 21 and integrally forming the outer peripheral wall 31 of the lid side projection 27 with the lid 26, the lid and the positive electrode current collector are formed as in the conventional battery. The number of components can be reduced compared to connecting the electrical plate via the leads, and the lid and the positive electrode current collecting terminal are directly bonded to reduce the number of joints to one. At the same time, the electric resistance between the lid and the positive current collecting terminal can be reduced.
[0026]
Further, the positive electrode side projection 22 is formed in a substantially cylindrical shape along the central axis C1, and the outer peripheral wall 31 of the lid side projection 30 is formed in a substantially cylindrical shape along the central axis C1.
Thereby, there is an advantage that the parts to be welded can be surely brought into contact with each other at the time of welding and positioning can be facilitated.
[0027]
In addition, the plurality of slits 22A formed in the positive electrode side protruding portion 22 reduce the reactive current when performing resistance welding, and perform good welding even when the thickness of the positive electrode current collector plate 21 is large. Even if the thickness of the electric plate 21 is large, the drawing process is easy. In addition, since the projections 24 provided on the joining end face 23 are quickly melted during welding, good joining can be achieved even when the contact pressure between the lid and the positive electrode current collector plate is reduced, so that the projections in the joining step This is effective for preventing the part from being deformed. The shape of the projection is not particularly limited, and a linear projection extending in a ring shape can be applied in addition to the dot-shaped projection shown in FIG.
[0028]
Next, the second and third embodiments will be described with reference to FIGS.
The alkaline storage battery 40 of the second embodiment shown in FIG. 3 differs from the alkaline storage battery 40 of the first embodiment in that a positive electrode current collector 41 and a lid 42 are used instead of the positive electrode 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 alkaline storage battery 10.
[0029]
The positive electrode current collector 41 has an opening 41A formed at the center of the positive electrode 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 42 has a substantially cylindrical lid-side projection (projection) 44 extending toward the positive electrode current collector 41 along the central axis C1 of the lid 42. The lid-side protruding portion 44 has an outer peripheral wall 45 formed in an annular shape, and an inner side surface 46 of the outer peripheral wall 45 is formed to be flush with an outer peripheral portion 47 of the lid portion 42, and an opening 46 </ b> A is formed at the center of the inner side surface 46. Is formed. The opening 46A is closed by the safety valve 28.
[0031]
The lid-side protrusion 44 is formed integrally with the lid 42 by, for example, drawing. Therefore, the lid-side protrusion 44 can be easily formed on the lid 42.
The lid 42 is a member formed of a material having conductivity such as, for example, nickel or a nickel-plated steel plate (SPCC), but is not limited thereto.
[0032]
The lid 42 has a thickness t3 of 0.8 to 1.5 mm.
If the plate thickness t3 is less than 0.8 mm, it is difficult to secure strength enough 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 26 is set to 0.8 to 1.5 mm.
[0033]
The cover-side protrusion 44 of the cover 42 is extended toward the positive electrode current collector plate 41, and the protrusion 43 of the positive electrode current collector 41 is joined to the tip 45 </ b> A of the outer peripheral wall 45 of the cover protrusion 44. Is 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 arranged so as to pass through the shortest distance between the positive electrode current collector plate 41 and the lid 42. As a result, the current path can be shortened, so that the resistance can be reduced and the output can be increased.
In addition, since the outer peripheral wall 45 of the lid-side projection 44 is integrally formed with the lid 42, the number of components can be reduced, and the number of joining steps can be reduced.
[0035]
Further, 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 becomes uniform, and the position of the welded portion during welding is easily positioned. In addition, there is an advantage that the pressure resistance when the parts to be welded are brought into contact with each other at the time of welding is high and deformation is difficult.
[0036]
The alkaline storage battery 50 of the third embodiment shown in FIG. 4 is different from the first embodiment in that a positive electrode current collector 51 and a lid 52 are used instead of the positive electrode 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 alkaline storage battery 10.
[0037]
The positive electrode current collector 51 has a substantially cylindrical positive-side protrusion (projection) 53 extending toward the lid 52 along the central axis C1 of the positive electrode current collector 51. An opening 54A is formed at the center of the tip 54 of the positive electrode side projection 53, and, for example, four protrusions 55 are formed around the opening 54A.
[0038]
The positive electrode side protruding portion 53 is formed integrally with the positive electrode current collector 51 by, for example, drawing. For this reason, the positive electrode side projection 53 can be easily formed on the positive electrode current collector plate 51.
The positive electrode current collector 51 is a member formed of a material having conductivity, such as nickel or a nickel-plated steel plate (SPCC), but is not limited thereto.
[0039]
The thickness t4 of the positive electrode current collector plate 51 is set to 0.2 to 0.5 mmmm.
When the plate thickness t4 is less than 0.2 mm, there is a disadvantage that the electric resistance is high. Further, sufficient contact pressure cannot be obtained in welding with the lid portion 26, and it is difficult to perform welding. On the other hand, if the plate thickness t4 exceeds 0.5 mm, the heat capacity difference 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 the safety valve 28.
The lid 52 is a member formed of a material having conductivity such as nickel or a nickel-plated steel plate (SPCC), but is not limited thereto.
[0041]
By extending the positive-side projecting portion 53 of the positive-electrode current-collecting plate side 51 toward the lid portion 52 and joining the projection 55 formed at the tip end 54 of the positive-side projecting portion 53 to the lid portion 52, the lid portion 52 is connected to the positive electrode collecting portion. It was configured to be electrically connected to the electric plate 51.
[0042]
Therefore, the positive electrode-side protruding portion 53 can be arranged so as to pass through the shortest distance between the positive electrode current collector plate 51 and the lid portion 52. As a result, the current path can be shortened, so that the resistance can be reduced and the output can be increased.
Further, by integrally forming the positive electrode side projection 53 on the positive electrode current collector plate 51, the number of components can be reduced, and additionally, the number of joining steps can be reduced.
[0043]
In addition, 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 position of the welded portion at the time of welding becomes easy, and There is an advantage that the pressure resistance when the parts to be welded are brought into contact with each other at the time of welding is high and deformation is difficult.
[0044]
Note that the present invention is not limited to the above-described embodiment, but can be appropriately modified, improved, and the like. The material, shape, dimensions, form, number, location, thickness, and the like of the portion, the lid-side protrusion, and the like are arbitrary and are not limited as long as the present invention can be achieved.
[0045]
【The invention's effect】
As described above, according to the present invention, as described in claim 1, by projecting the protrusion from one of the positive electrode current collector plate and the lid toward the other, the positive electrode current collector plate The protrusion can be arranged so as to pass through the shortest distance between the cover and the cover.
Therefore, since the current path can be shortened, the resistance can be reduced and the output characteristics of the battery can be improved.
[0046]
In addition, the number of components can be reduced by integrally forming the protruding portion on one of the positive electrode current collector plate and the lid, and the number of components can be reduced, thereby reducing the number of joining steps.
As described above, the number of components and the number of joining steps can be reduced, so that the cost can be reduced.
[0047]
According to the present invention, as described in claim 2, by providing a projection on the single surface of the joint, the contact pressure between the lid and the positive electrode current collector terminal when welding the two can be reduced. It is effective to prevent deformation.
[0048]
Further, according to the present invention, as described in claim 3, the length of the current collection path is reduced by forming the one of the protruding portion positive electrode current collector plate and the lid portion into a substantially cylindrical shape along the central axis. In addition to being uniform, the positioning of the welded portion at the time of welding is facilitated, and the welding pressure at the time of bringing the parts to be welded into contact with each other at the time of welding is high, and it is difficult to deform.
[0049]
According to the present invention, as described in claim 4, since the plurality of slits extending radially from the center are formed in the protruding portion, the reactive current when performing resistance welding is reduced, and the current collecting terminal is reduced. A good welding can be performed even if the thickness of the steel sheet is large, and drawing work is easy.
[Brief description of the drawings]
FIG. 1 is a 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 sectional view showing a second embodiment of the alkaline storage battery according to the present invention.
FIG. 4 is a sectional view showing a third embodiment of the alkaline storage battery according to the present invention.
FIG. 5 is a 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 generating elements 11A, 11B Both end faces 12 of power generating element Separator 13 Negative electrode 14 Positive electrode 15 Negative core material 16 Positive core material 17 Negative core material exposed portion 18 Positive core material exposed portion 20 Negative current collector plate 21 , 41, 51 Positive electrode current collector plate 23 Joining end surface 24 Projections 26, 42, 52 Lids 22, 53 Positive side protrusion (protrusion)
30, 44 Lid-side protrusion (projection)
C1 center axis

Claims (4)

A power generating element in which a negative electrode and a positive electrode are wound through a separator, and electric resistance welding to a negative electrode core exposed portion and a positive electrode core exposed portion in which the core is exposed from the separator on both end surfaces of the power generating element, laser A negative electrode current collector plate and a positive electrode current collector plate joined by welding or beam welding, a bottomed cylindrical battery case containing the power generation element, the negative electrode current collector plate and the positive electrode current collector plate, and the battery case; An alkaline storage battery having a lid that closes,
One or both of the positive electrode current collector plate and the lid portion has an integrally formed protrusion protruding from one to the other, and the positive electrode current collector plate and the lid portion are the protrusion portions An alkaline storage battery, wherein the alkaline storage battery is joined via a wire. 2. The alkaline storage battery according to claim 1, wherein a projection is provided on at least one joint end surface of the lid and the positive electrode current collector terminal. 3. The alkaline storage battery according to claim 1, wherein the protruding portion has a substantially cylindrical shape along a central axis of one of the positive electrode current collector plate and the lid portion. 4. The alkaline storage battery according to claim 3, wherein a plurality of slits extending radially from a center are formed in the protrusion.

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