JP4698134B2 - Battery and manufacturing method thereof - Google Patents

Description

  The present invention relates to a battery such as an alkaline storage battery and a method for manufacturing the same, and more particularly to a technique for improving the configuration around a positive electrode current collector.

Alkaline storage batteries such as nickel cadmium (Ni-Cd) batteries and nickel hydride (Ni-MH) storage batteries are widely used as power sources for electric tools, electric bicycles, electric motorcycles and the like. In these applications, charge / discharge characteristics at a large current are often required, so that the internal resistance of the battery needs to be reduced as much as possible.
As a general manufacturing method of an alkaline storage battery, first, a belt-like positive electrode plate and a negative electrode plate are wound with a separator interposed therebetween to form a power generation element (electrode body). A current collector is connected to each electrode above and below this electrode body, and this is housed in a metal outer can. Then, a current collecting lead part (specifically, a lead part connected to the current collector) as a conductive member derived from the positive electrode current collector and a terminal provided on the sealing body are welded, and then the sealing body is attached to the outer can. Attached to the opening and crimped to produce a sealed battery.

In such an alkaline storage battery manufacturing method, for example, as in Patent Document 1, the purpose of ensuring the stability when welding the current collecting lead portion and the terminal provided on the sealing body, and the sealing device attached to the outer can A technique using a current collecting lead part that promotes local bending deformation is known for the purpose of coping with a change in the overall height of the battery when caulking the body. If such a current collector lead part is used, the current collector lead part is brought into contact with the terminal on the back surface of the sealing body while the sealing body is attached to the opening of the outer can and the inside of the battery is closed, and resistance welding is performed from the outside. And can be welded. In addition to improving the work efficiency of resistance welding, this method can significantly reduce the length of the current collector lead part compared to the above-mentioned general prior art, and shorten the current collection path to reduce the internal resistance. There is an effect that it is reduced.
JP 2002-231216 JP

  However, since the current collecting lead portion used in the above technique needs to be processed into a special and complicated shape as compared with the conventional product, it is industrially expensive and expensive. In addition, the current collecting lead portion after the battery is completed has a certain three-dimensional structure even after completion, and specifically, a space of at least two plate thicknesses is required inside the battery. For this reason, the said current collection lead will occupy a big space especially in the height direction inside a battery. Such a space is a problem to be improved because it leads to a decrease in the energy density of the battery.

Moreover, this subject exists not only for alkaline storage batteries but also for general batteries.
The present invention has been made in view of the above problems, and its purpose is to provide a battery for resistance-welding a terminal of a sealing body and a current collecting lead in a state where the sealing body is attached to an opening of an outer can. An object of the present invention is to provide a battery capable of reducing internal resistance without reducing energy density, and a manufacturing method capable of manufacturing the battery at low cost.

  In order to solve the above-described problems, the present invention provides an electrode body composed of positive and negative electrodes and a separator that is housed in an outer can, and one electrode of the electrode body is electrically connected with a terminal and a conductive member disposed on a sealing body. The battery is connected and the opening of the outer can is sealed with a sealing body, wherein the conductive member is a current collector made of a plate-like member connected to the one electrode, and the current collector is separate from the current collector And a lead part made of a plate-like member that electrically connects the current collector and the terminal, the lead part being a flat part in contact with the current collector surface, A convex portion that contacts the sealing body or the terminal, and the convex portion is compressed and deformed in the thickness direction of the planar portion in accordance with the plane of the planar portion in a state where the outer can is sealed with the sealing body. It was set as the structure.

  In the present invention, an electrode body composed of positive and negative electrodes and a separator is housed in an outer can, and one electrode of the electrode body is electrically connected to a terminal disposed on the sealing body by a conductive member, and the opening of the outer can The battery is sealed by a sealing body, and the conductive member is formed by bending a strip-shaped plate material along the width direction, and connects one region with the bent portion as a boundary to the one electrode. Current collector part, the other region is a lead part for connecting the sealing body or the terminal, the lead part is connected to the sealing body or the terminal from the current collector part from the connection point The lead portion in the state where the extension portion is provided in the direction away from the outer can and is sealed with the sealing body is compressed in the thickness direction of the plate material and is in surface contact with the current collector portion. You can also.

In the case of this configuration, the extension can be insulated from the current collector. Further, the extension portion can be provided with a length equal to or longer than the distance from the boundary to the connection point.
Further, the present invention is used as a conductive member for electrically connecting a plate-like current collector connected to one electrode of an electrode body housed in an outer can and a terminal disposed on a sealing body. A lead part, the lead part is made of a plate-like member, and has a flat part that is in contact with the surface of the current collector, and a convex part that is in electrical contact with the sealing body or the terminal. In the state sealed with the sealing body, the convex portion may be configured to be compressed and deformed into a plate shape in the thickness direction of the flat portion in accordance with the plane of the flat portion.

  In the battery manufacturing method of the present invention, the electrode body composed of the positive and negative electrodes and the separator is housed in the outer can, and the sealing body is attached to the opening of the outer can while the one electrode of the electrode body is attached. A battery manufacturing method comprising: a welding step of welding a conductive member connected to an electrode to a sealing body or a terminal disposed on the sealing body; and a sealing step of sealing an opening of an outer can with a sealing body by caulking. The conductive member used in the welding step is a current collector made of a plate-like member connected to the one electrode, and the current collector is separate from the current collector and the terminal. A lead portion made of a plate-like member to be connected, and the lead portion has a flat portion in contact with the surface of the current collecting portion, and a convex portion welded to the sealing body or the terminal, in the sealing step In the caulking process Pressurized internal Sokan with a sealing member, the convex portion of the lead portion, in accordance with the plane of said planar portion, can be compressed and deformed in the thickness direction of the flat portion.

  In the present invention, an electrode body composed of positive and negative electrodes and a separator is housed in the outer can, and the sealing body is attached to the opening of the outer can, and the electrode body is connected to one electrode of the electrode body. A method for manufacturing a battery comprising: a welding step of welding a conductive member to a sealing body or a terminal disposed on the sealing body; and a sealing step of sealing an opening of an outer can with a sealing body by caulking, wherein the welding step includes The conductive member to be used is a current collecting part for connecting one region with the one electrode, the other region being the sealing body or the above, with the band-shaped plate member being bent along the width direction. The lead portion is welded to the terminal, and the lead portion has a connection point with the terminal provided in a range of a distance of half or less of the inner diameter of the outer can from the boundary, and in a direction away from the current collector from the connection point. Established And it is one having an extension, in the sealing step, the pressurized inner outer can by crimping, compressing the lead portion in the thickness direction of the plate, can be contacted with the current collector part.

  In this case, in the welding step, when the extension portion comes into contact with the back surface of the sealing body, the sealing body inside the outer can can be supported or positioned by the elastic force of the extension portion.

According to the present invention described above, in the conductive member as the current collecting lead portion constituted by the current collecting portion and the lead portion, the lead portion having a three-dimensional structure including the flat portion and the convex portion is, for example, a conductive member. Since it can be easily manufactured by punching and bending, it is excellent in low cost.
In addition, the convex part of the lead part comes into contact with the terminal of the sealing body, and then the convex part is crushed and compressed in the thickness direction along the surface of the current collector when the overall battery height is lowered by the pressure applied by caulking. Since it is deformed, the current collector and the sealing body sandwich the both sides of the rolled lead portion. Therefore, when the battery is completed, the positive electrode lead plate only needs to have a space of one plate thickness, and does not require a bulky space. For this reason, there is a margin in the space inside the battery, so that the energy density of the battery can be improved accordingly.

  Further, the belt-shaped plate member as the conductive member is bent along the width direction, and a current collector for connecting one region with the bent portion as a boundary to the one electrode, and the other region as the current collector and A lead portion for connecting the terminal, and in the lead portion, a connection point with the terminal provided in a range of a distance of half or less of the inner diameter of the outer can from the boundary, and from the current collecting portion from the connection point If an extension is provided in the direction of moving away, the connection point (specifically, the welding point) can be provided at a sufficiently close distance from the boundary, and the welding point is located directly below the terminal of the sealing body. Can do. Thereby, it becomes possible to resistance-weld the terminal of the sealing body at the connection point while the sealing body is attached to the opening of the outer can.

  And the positive lead part is crushed by the pressurization accompanying the caulking process after resistance welding, and the positive electrode current collector part is in surface contact, so the current collection path is shortened and good conductivity is ensured. An effect of suppressing resistance is exhibited. In addition, since the positive electrode lead portion requires only a single plate thickness, an extra space is unnecessary in the battery as compared with the conventional case, and the energy density can be improved.

  Since the conductive member has a simple structure that can be manufactured by pressing a steel plate and applying some shape processing, the conductive member can be manufactured at a relatively low cost. By using such a conductive member, it is possible to produce a battery at a lower cost than in the past.

(Embodiment 1)
1-1. Configuration of Alkaline Storage Battery FIG. 1 is a cross-sectional perspective view of a cylindrical nickel cadmium storage battery (Ni-Cd storage battery) according to the first embodiment. Although the case where the present invention is applied to an alkaline storage battery will be described here, the present invention may be other types of batteries.

The Ni-Cd storage battery includes, for example, an SC-sized cylindrical outer can 6 and has a configuration in which an electrode body 4, an electrolytic solution, and the like are accommodated. As an example, the nominal capacity can be 2.5 Ah. An alkaline solution is used as the electrolytic solution, and here, as an example, an alkaline aqueous solution mainly composed of potassium hydroxide is used.
The cylindrical outer can 6 is made of Ni-plated Fe material processed into a bottomed cylindrical shape, but in addition to this, considering the type and characteristics of the battery, stainless steel, aluminum, etc. Materials can be used. The cylindrical side surface 61 of the outer can 6 is coated with a coating or resin film for external insulation. The negative electrode current collector 5 is connected to the center of the bottom portion 62 of the outer can 6. Further, the opening 60 above the outer can 6 is sealed without a gap by caulking after the insulating / sealing gasket 11 and the sealing body 12 are fitted.

The sealing body 12 disposed in the opening 60 at the upper end of the outer can 6 is surrounded by the insulating gasket 11. The sealing body 12 is provided with an opening (gas vent hole) 14 in the center, and a dish-like positive electrode terminal 13 is mounted so as to cover the opening. At this time, the sealing body 12 and the positive electrode terminal 13 are electrically connected.
In the internal space of the sealing body 12 and the positive electrode terminal 13, a valve plate 8, a holding plate 9, and a coil spring 10 are placed in this order from bottom to top. Among these, the valve plate 8 and the holding plate 9 are pressed around the central opening 14 by the elastic force of the coil spring 10 to act as a safety valve. Instead of the valve plate 8, the holding plate 9, and the coil spring 10, a valve body made of an elastomer such as rubber may be used.

The electrode body 4 is formed by winding a positive electrode plate 1 and a negative electrode plate 2 in a spiral shape with a separator 3 interposed therebetween.
The positive electrode plate 1 is a sintered nickel positive electrode manufactured by forming a nickel sintered porous body on the surface of a punching metal and then filling the sintered porous body with an active material mainly composed of nickel hydroxide by a chemical impregnation method. It is a plate, and is connected to the positive electrode terminal 13 via the positive electrode current collector 70 having a porous disk part, the elliptical lead part 71 and the sealing body 12. A vibration isolating ring 15 made of an elastomer material is disposed around the positive electrode current collector 70 so that the electrode body 4 is not displaced. Alternatively, the positive electrode terminal 13 may be disposed on the perforated sealing body 12, and the battery inner side end portion of the positive electrode terminal 13 may be directly connected to the lead portion 71.

Here, the first embodiment is characterized in that a positive electrode current collector 70 and an elliptical lead portion 71 are used as the current collecting lead portion.
Similarly, the negative electrode plate 2 is a sintered cadmium negative electrode plate manufactured by filling the sintered porous body with an active material mainly composed of cadmium hydroxide by a chemical impregnation method, and is a porous disk made of Ni-plated Fe. The negative electrode current collector 5 is connected to the bottom 62 of the cylindrical outer can 6 that also serves as the negative electrode terminal.

Separator 3 is formed by processing a microporous film made of, for example, nylon or polypropylene, which is excellent in insulation, and is well impregnated with an electrolyte and electrically insulates positive electrode plate 1 and negative electrode plate 2 Used to do.
<Configuration of positive electrode lead>
FIG. 2 is a diagram illustrating a configuration of the positive electrode lead portion according to the first embodiment. 2 (a) is a perspective view, FIG. 2 (b) is a side view, FIG. 2 (c) is a top view, and FIG. 2 (d) is a front view. The positive electrode lead portion 71 shown here has a shape before the battery is manufactured, and is rolled into a substantially single plate state along the surface of the positive electrode current collector 70 after the manufacture, as will be described later.

The positive electrode lead portion 71 is made of a material obtained by applying nickel plating to a steel plate having a thickness of 0.30 mm. As shown in FIG. 2 (C), this is punched into an ellipse whose end in the major axis direction is cut, and then bent in the minor axis direction of the ellipse. The size of the positive electrode lead portion 71 before bending is set to be smaller than the size (diameter) of the positive electrode current collector 70.
As shown in FIG. 2 (a), the overall configuration is a flat portion 700a, 700b extending along the same plane as each other, and protruding in a mountain fold from the plane at the center of the steel plate (between the flat portions 700a, 700b). Symmetrically with the protruding portion 703 and the protruding portion, the flat portions 700a and 700b that are recessed in the valley fold and formed to have a plane parallel to the same plane as the flat portions 700a and 700b, Consists of. The flat portions 700a and 700b and the flat portions 700a and 700b are in contact with the surface of the positive electrode current collector 70 described later.

The protruding portion 703 can be set to a height of 1.7 mm as an example, and is formed from the center of the lead portion 71 to one end side along the long axis direction of the ellipse as shown in FIG. 2 (b). . A welding point A is provided at the top of the mountain fold of the protrusion 703. This indicates that resistance welding is performed with the positive electrode terminal 13 side through the back surface of the sealing body 12.
On the other hand, the welded portion 702 is valley-folded along the long axis direction of the ellipse, and is disposed at a position opposite to the protruding portion 703. As shown in FIG. 2 (d), the welded portion 702 has a shape in which the protruding portion 703 is partially folded back along the height direction so as to have a trapezoidal cross section. The height of both ends in the width direction of the welded portion 702 (the heights of the valley folded end portions 701a and 701b) is 1.2 mm as an example. The back surface of the welded portion 702 is a welding point B. This indicates a spot welded to the positive electrode current collector 70 side.

A slit 704 is provided between the protruding portion 703 and the welded portion 702. This communicates with the central opening 14 of the sealing body 12 and is for venting gas from the inside of the battery when the safety valve is activated. The slit 704 is provided not only for degassing but also for the purpose of causing the positive electrode lead portion 71 to be easily crushed during caulking during manufacturing.
Here, the positive electrode lead portion 71 is processed into an oval shape and is formed by bending such as mountain fold or valley fold processing, but the positive electrode lead portion 71 of the present invention has other shapes. Also good. For example, the whole may be formed into a band shape, and the bending process may be performed along the width direction.

Note that the configuration of the positive electrode lead portion 71 is not limited to this example, and may be any structure as long as it includes at least a flat portion in contact with the positive electrode current collector and a protruding portion 703 as a convex portion in contact with the back surface of the sealing body. The convex portion needs to have a shape that is crushed in the thickness direction of the steel sheet by the pressure applied during the caulking process of the sealing body.
Moreover, the said convex part is not limited to the shape made into the peak of a mountain fold, For example, a convex part may be formed in the trapezoidal cross-sectional shape, and you may make it contact the sealing body back surface in the part equivalent to the upper side. . Further, the positive electrode lead portion 71 may have a configuration in which a mountain fold portion is provided above and below in the thickness direction.

Furthermore, in the above configuration example, the back surface of the welded portion 702 is formed in a planar shape to facilitate spot welding, but this is not an essential structure and may have a shape other than a plane.
Furthermore, the number of the protrusions 703 is not limited to the one provided, but a plurality of the protrusions 703 may be provided.

<About the configuration of the positive electrode current collector>
FIG. 3 is a front view showing the configuration of the positive electrode current collector of the first embodiment.
The positive electrode current collector 70 is made of a material obtained by applying nickel plating to a steel plate having a thickness of 0.30 mm. As shown in FIG. 3, punching is performed so as to have a large number of holes 705. Further, it is desirable to form a substantially disk shape in accordance with the shape of the cylindrical outer can 6.

The dotted line shown in the figure indicates the position where the positive electrode lead portion 71 is placed, and the welding point C indicates the position where the positive electrode current collector 70 and the positive electrode lead portion 71 are spot welded together.
<Battery manufacturing method>
In the battery manufacturing method, first, a nickel sintered porous body is formed on the surface of a punching metal, and then the sintered porous body is filled with an active material mainly composed of nickel hydroxide by a chemical impregnation method. A positive electrode plate is obtained.

Further, an active material mainly composed of cadmium hydroxide is filled into the sintered porous body by a chemical impregnation method to obtain a sintered cadmium negative electrode plate.
The positive electrode plate and the negative electrode plate thus obtained are wound through a separator to produce the electrode body 4. Then, the positive electrode plate and the positive electrode current collector 70 are spot-welded above the electrode body 4. On the other hand, the negative electrode plate 2 and the negative electrode current collector 5 are spot-welded below the electrode body.

This is housed inside the outer can 6, and the negative electrode current collector 5 is spot welded to the outer can bottom 62. Thereafter, the vibration isolating ring 15 is inserted so as to cover the periphery of the positive electrode current collector 70.
Subsequently, as described in FIG. 3, the positive electrode current collector 70 and the lead portion 71 are spot-welded to each other at welding points B and C.
Thereafter, the outer can opening 60 is sealed with the sealing body 12 through the insulating gasket 11, the lead portion 71 and the positive electrode terminal 13 are resistance-welded, and the outer can opening 60 is crimped with the sealing body 12 and sealed. However, at this time, according to the positive electrode lead portion 70 and the positive electrode current collector 71 having the above-described configuration, the following effects can be achieved when the battery is manufactured.

Here, FIG. 4 is a diagram showing a state when the battery is manufactured in the first embodiment. Fig. 4 (a) shows the resistance welding process, and Fig. 4 (b) shows the caulking process.
First, as shown in FIG. 4 (a), resistance welding electrodes W1 and W2 are brought into contact with the upper surface of the sealing body and the bottom of the outer can, respectively. And, for example, by applying a current of about 3 kA at a voltage of 20 V between the electrodes W1, W2 for 10 seconds, while ensuring the welding stability with the outer can opening 60 closed by the sealing body 12, the welding point A The positive electrode lead portion 71 and the sealing body 12 are resistance welded. Since the sealing body 12 is connected to the positive terminal 13 as shown in FIG. 1, the positive lead portion 71 is electrically connected to the positive terminal 13 by the resistance welding.

  After performing resistance welding in this manner, both the outer can opening 60 and the sealing body 12 are crimped using a jig to seal the inside of the battery. During the caulking process, the sealing body 12 is pressurized toward the inside of the battery. This pressurization changes the overall height of the battery. At this time, as shown in FIG. 4B, the positive electrode lead portion 71 is fixed at the welding points A and B as a feature of the present invention. It is rolled in the thickness direction while making surface contact along the surface. By making this surface contact, the positive electrode current collector 71 and the positive electrode lead part 70 can shorten the current collection path and reduce the internal resistance. Thereby, for example, the operating voltage can be improved in charging / discharging with a large current, and heat can be suppressed and stable driving can be achieved.

In the present invention, the positive electrode current collector 71 and the positive electrode lead portion 70 do not necessarily need to be brought into surface contact when the shortening of the current collection path need not be considered so much.
Further, by the rolling, the shape of the positive electrode lead portion 71 returns to a substantially single plate state, and the positive electrode current collector 70 and the sealing body 12 are sandwiched between both surfaces of the rolled positive electrode lead plate 71, and the positive electrode lead portion 71 is electrically connected to the positive electrode terminal 13 through the sealing body 12. Therefore, the positive electrode lead plate 71 after rolling only needs to have a space of one sheet thickness, and does not require a bulky space beyond that. For this reason, in the first embodiment, there is room in the space inside the battery, so that for example, the electrode body 4 having a larger size can be accommodated, and the energy density of the battery can be improved.

Further, when the positive electrode lead portion 70 is rolled by caulking, it finally comes into surface contact with the sealing body 12 side at its plate-like surface. As a result, the current collection path between the positive electrode lead portion 70 and the sealing body 12 side (positive electrode terminal 13) is shortened, the conductivity is improved, and the effect of suppressing internal resistance is also exhibited.
Even in this case, the positive electrode lead portion 70 does not need to be brought into surface contact with the sealing body 12 side when it is not necessary to consider the shortening of the current collecting path so much.

In addition, since both the positive electrode lead plate 70 and the positive electrode current collector 71 have a simple structure that can be manufactured by pressing a steel plate and applying some shape processing, the positive electrode lead plate 70 and the positive electrode current collector 71 can be manufactured relatively inexpensively. By using such positive electrode lead plate 70 and positive electrode current collector 71, it is possible to produce a battery at a lower cost than in the past.
(Embodiment 2)

The Ni—Cd storage battery of the second embodiment is different from the first embodiment in the configuration of the positive electrode current collector and the positive electrode lead part. Other configurations are the same as those in the first embodiment.
FIG. 5 is a front view of a conductive member (consisting of a positive electrode current collector plate and a positive electrode lead part) serving as a positive electrode current collecting lead part according to the second embodiment.
The positive electrode conductive member 80 shown in the figure is formed by applying nickel plating to a steel plate having a thickness of 0.30 mm and punching it. The positive electrode conductive member 80 includes a disk-shaped positive electrode current collector 801 processed according to the cross-sectional shape of the cylindrical outer can 6 and a rectangular positive electrode lead portion 802.

Here, the welding point D in the positive electrode lead portion 802 is provided in a range of a distance of not more than half of the inner diameter of the outer can 6 from the boundary line XX ′ between the positive electrode current collector 801 and the positive electrode lead portion 802. Providing the welding point D at such a position is a main feature of the second embodiment.
A region from the welding point D to the boundary line XX ′ is referred to as a lead fulcrum portion 8021, and a region from the welding point D to the end (extension line YY ′ in the drawing) is referred to as a lead extension portion 8022.

In use, the positive electrode conductive member 80 is bent at the boundary line XX ′ and processed so that the positive electrode current collector portion 801 and the positive electrode lead portion 802 have a “cross-section” cross-sectional shape.
According to the second embodiment having the above-described configuration, the following effects can be achieved when manufacturing the battery.
Here, FIG. 6 is a diagram showing a state when the battery is manufactured in the second embodiment. FIG. 6 (a) shows a resistance welding process between the positive electrode lead portion and the sealing body, and FIG. 6 (b) shows a state during caulking. The positive electrode plate 1 of the electrode body 4 housed inside the outer can 6 is previously welded to the positive electrode current collector 801 by spot welding.

  As shown in FIG. 6 (a), in the present second embodiment, the back surface of the sealing body 12 is in a state of being disposed so as to face the positive electrode lead portion 802 disposed above the inside of the outer can 6. In the second embodiment, since the welding point D is provided in a range of a distance that is less than half of the inner diameter of the outer can 6 from the boundary line XX ′, the sealing body 12 can be appropriately adjusted within this distance range. In a state in which is attached to the outer can opening 60, the welding point D can be positioned immediately below the positive electrode terminal 13. As a result, resistance welding electrodes W1 and W2 can be arranged above and below the battery in the same manner as in the first embodiment, and resistance welding can be performed with the outer can opening 60 closed by the sealing body 12.

  When the bending at the boundary line XX ′ is insufficient (when the positive electrode lead portion 802 faces upward from the horizontal), the lead extension portion 8022 contacts the back surface of the sealing body 12 during welding. It acts as a guide for bending the positive electrode lead portion 802 by pressurizing. In addition, when the bending of the positive electrode lead portion 802 increases due to pressurization during welding, the lead extension portion 8022 contacts the positive electrode current collector 801 and acts as a spring support by elastic force. As a result, stable welding is possible by applying a constant pressure during welding. Specifically, if the length of the lead extension portion 8022 (extension line YY ′) is set to be longer than the length from the welding point D to the boundary line XX ′, the above-mentioned spring effect is achieved by the elasticity of the lead extension portion 8022. Strength increases and support capacity increases. In addition, since the electrical resistance of the lead extension portion 8022 is greater than that of the lead fulcrum portion 8021, when the lead extension portion 8022 and the positive electrode current collector 801 are in contact during welding, the current flowing through the lead extension portion 8022 is reduced, This makes it difficult to fly away. For this reason, in the configuration in which the contact between the positive electrode current collector 801 and the positive electrode lead 802 is not covered with an insulator, more stable welding is possible.

After resistance welding is performed in this manner, as shown in FIG. 6B, crimping is performed on both the outer can opening 60 and the sealing body 12. Due to the pressurization accompanying the caulking process, the bent portion of the positive electrode lead portion 802 near the boundary line XX ′ is further crushed.
In this caulking process, if the positive electrode lead portion 802 is brought into surface contact with the positive electrode current collector 801, the current collection path is shortened, the conductivity is improved, and the internal resistance is reduced. So desirable. However, the positive electrode lead portion 802 is not necessarily in surface contact with the positive electrode current collector 801.

According to such a configuration, since the positive electrode lead portion 802 requires only one space for the plate thickness, an extra space is unnecessary in the battery compared to the conventional case, and the energy density can be improved. .
Further, the conductive member 80 can be manufactured by pressing a steel plate and performing some shape processing in the same manner as in the first embodiment, and has a simple structure with a small number of parts, so that it can be made relatively inexpensively. . By using such a conductive member 80, it is possible to produce a battery at a lower cost than in the past.

In the above example, the configuration example in which the current collecting path is shortened by bringing the positive electrode current collecting unit 801 and the positive electrode lead unit 802 into surface contact with each other has been described. Good.
7A is a cross-sectional view showing another configuration of the conductive member 80. FIG. The conductive member 80 is in a state of being crushed by performing a caulking process. In the configuration example shown in this figure, an insulating member (insulating tape 803 as an example) is interposed between the positive electrode current collector 801 and the positive electrode lead 802 so that they do not conduct due to the surface contact. Instead of the insulating tape 803, an insulating paint may be used, or an anti-vibration ring 15 that is an insulating anti-vibration member may be used.

  According to such a configuration, since the positive electrode current collector 801 and the positive electrode lead 802 are integrally connected to each other in the vicinity of the boundary line XX, good conduction is achieved. Here, since the welding point D of the second embodiment is provided very close to the boundary line XX, the current collection path can be shortened even with such a configuration. In the figure, the positive electrode current collector 801 and the positive electrode lead 802 have a configuration having substantially the same length, but if the welding point D is set to the position as described above, the extension line YY ′ It is possible to reduce the reactive current generated when the battery is used by cutting away the lead extension portion 8022 along the line.

Further, in the second embodiment, a conductive member 80 having the configuration shown in FIG. 7 (b) may be used. The example shown in the figure shows the configuration before the caulking process. Here, the conductive member 80 is bent along the boundary line XX and also bent at the welding point D, and the lead extension portion 8022 and the lead fulcrum portion 8021 form a mountain-folded cross-sectional shape.
In such a configuration, the lead extension portion 8022 is initially in contact with the positive electrode current collector 801 only at its end, but spreads along the surface of the positive electrode current collector 801 by being pressurized in the caulking process. It is crushed in the thickness direction. Therefore, even with the conductive member 80 having such a configuration, substantially the same effect as the conductive member having the configuration shown in FIG. 5 can be obtained.
(Performance comparison experiment)
Here, a performance comparison experiment was performed on the Ni—Cd storage batteries of Embodiments 1 and 2 above and the Ni—Cd storage battery of the comparative example.

<Comparative battery>
For the comparative battery used in the performance comparison experiment, as shown in FIG. 8 (a), the configuration itself uses the same positive electrode current collector (conductive member) as in the second embodiment. In contrast, the position of the welding point E is set near the tip of the current collecting lead portion 802 on the side opposite to the boundary line XX ′ side. In the manufacturing process of the comparative battery, first, as in the second embodiment, the positive electrode current collector and the negative electrode current collector are welded to the upper and lower sides of the electrode body. Then, this is accommodated in an outer can and the negative electrode current collector is welded to the inner surface of the outer can bottom.

  Then, using the welding electrodes W3 and W4, the current collecting lead part is welded to the sealing body side. At this time, in the comparative example battery, the position of the welding point E is the boundary line compared to the welding point D of the second embodiment. Since it is farther than X-X ', it cannot be welded while the sealing body is attached to the outer can opening. For this reason, at the time of manufacture, the comparative battery has the effect of resistance welding in Embodiment 2 (that is, the effect that the current collecting lead part can be resistance-welded to the sealing body side while the sealing body is mounted on the outer can opening). I can't get it. Thus, in the comparative battery, as shown in FIG. 8 (b), resistance welding is performed with the sealing body from the back surface of the current collecting lead portion with the sealing body removed from the outer can opening. After this resistance welding, the comparative example battery is manufactured by mounting the sealing body on the outer can opening and performing the crimping process.

Moreover, since it is necessary to weld in the state which removed the sealing body from the exterior can opening part in the comparative example battery, it is necessary to set the extension part of a current collection lead part long. As a result, in the comparative battery, even if the sealing body is attached to the opening of the outer can and crimped, the extension portion remains bent and the current collecting portion and the lead portion do not come into surface contact.
The performance measurement condition is that at an ambient temperature of 25 ° C., charge at 2.5 A for 72 minutes, then stop for 60 minutes, discharge at a constant current (40 A), and stop discharging when the battery voltage reaches 0.7V.

The results of such measurement were as follows.
<Measurement results>

この表1に示す測定結果から明らかなように、実施例1、2の電池では、いずれも比較例電池に比べて大電流放電時の作動電圧が高く発揮されている。また、実施例1、2の電池では、放電後の内部抵抗上昇も低く抑えられることが分かった。

As is clear from the measurement results shown in Table 1, in the batteries of Examples 1 and 2, the operating voltage during large current discharge is higher than that of the comparative battery. In addition, in the batteries of Examples 1 and 2, it was found that the increase in internal resistance after discharge can be suppressed to a low level.

  From these results, if at least one of the conductive member, the positive electrode lead portion, and the positive electrode current collector in the present invention is used, the positive electrode lead portion and the sealing body side are resisted in a state where the sealing body is attached to the outer can opening portion. On the other hand, it was found that the current collecting path on the positive electrode lead portion and the sealing body side can be shortened compared to the conventional case, and the internal resistance can be reduced to improve the operating voltage at the time of high rate discharge of the battery.

In the batteries of Examples 1 and 2, the sintered electrode was used for both the positive electrode plate and the negative electrode plate. However, the present invention is not limited to this, and a non-sintered electrode such as a paste type is used. The same good results were obtained when the experiment was carried out with a battery using.
(Other matters)

In the first and second embodiments, the configuration example in which the positive electrode terminal is provided on the sealing body side and the outer can bottom portion is the negative electrode is shown.Naturally, the present invention is not limited to this, and the negative electrode terminal is provided on the sealing body side. It is good also considering the exterior can bottom as a positive electrode.
The present invention is not limited to a cylindrical battery, and may be applied to a prismatic battery.
Furthermore, the configuration of the electrode body is not limited to the configuration of a wound body in which positive and negative bipolar plates are wound via a separator, but may be applied to a stack type in which strip-like positive and negative bipolar plates are stacked via a separator, for example. Good.

  Furthermore, solder welding may be used in addition to this in the spot welding in the above example.

  The present invention can be applied to alkaline storage batteries.

2 is a cross-sectional perspective view of a cylindrical alkaline storage battery according to Embodiment 1. FIG. It is a figure which shows the structure of a lead part. It is a figure which shows the structure of a positive electrode electrical power collector. It is a figure which shows the mode of a welding process and a crimping process. 6 is a diagram showing a configuration of a conductive member in Embodiment 2. FIG. It is a figure which shows the mode of a welding process and a crimping process. It is a figure which shows the structure of the electrically-conductive member using an insulating member. It is a figure which shows the structure of the battery in a comparative example.

Explanation of symbols

1 Positive electrode plate
2 Negative electrode plate
3 Separator
4 Electrode body
5 Negative electrode current collector
6 Exterior can
12 Sealing body
15 Anti-vibration ring
62 Exterior can bottom
70 Positive current collector
71 Positive lead part
80 Conductive members
700a, 700b flat part
701a, 701b Both ends of valley fold
702 weld
703 Protrusion
704 slit
705 holes
801 Positive current collector
802 Positive electrode lead
803 insulation tape
8021 Lead fulcrum
8022 Lead extension

Claims (7)

An electrode body composed of positive and negative electrodes and a separator is housed in an outer can, and one electrode of the electrode body is electrically connected to a terminal disposed on the sealing body with a conductive member, and the opening of the outer can is a sealing body. A sealed battery,
The conductive member is a current collector made of a plate-like member connected to the one electrode, and is separate from the current collector, and electrically connects the current collector and the terminal. A lead portion made of a plate-like member
The lead part has a flat part in contact with the surface of the current collector part, and a convex part in contact with the sealing body or the terminal,
In the state where the outer can is sealed with the sealing body, the convex portion is compressed and deformed in the thickness direction of the flat portion in accordance with the plane of the flat portion, and is in surface contact with the surface of the current collecting portion. A battery characterized by being. An electrode body composed of positive and negative electrodes and a separator is housed in an outer can, and one electrode of the electrode body is electrically connected to a terminal disposed on the sealing body with a conductive member, and the opening of the outer can is a sealing body. A sealed battery,
The conductive member is formed by bending a band-shaped plate material along the width direction, and a current collecting part for connecting one region with the bent portion as a boundary to the one electrode, and the other region as the sealing body or It is a lead part for connecting the terminal,
The lead portion includes a connection point between the sealing member or the pin has an extension provided in a direction away from the collector portion than the connection point,
The connection point is provided in a range of a distance of half or less of the inner diameter of the outer can from the boundary,
The battery, wherein the lead portion in a state where the outer can is sealed with a sealing body is compressed in the thickness direction of the plate material and is in surface contact with the current collecting portion. Lead used for a conductive member for electrically connecting a plate-like current collector connected to one electrode of an electrode body housed in a battery outer can and a terminal disposed on a battery sealing body Part,
  It consists of a plate-shaped member
  A convex part that is mountain-folded along the width direction or the minor axis direction of the member, and is in electrical contact with the sealing body or the terminal;
  And two flat portions disposed at both ends of the convex portion, and in contact with the current collector surface,
  In a state where the outer can is sealed with a sealing body, the convex portion is compressed and deformed into a plate shape in the thickness direction of the planar portion in accordance with the plane of the planar portion, and is in surface contact with the current collector surface. A lead part characterized by that. 4. The method according to claim 3, further comprising: a welded portion with a current collector formed so as to have a surface on the same plane as the two plane portions by processing a part of the convex portion. Lead part . In a state in which an electrode body composed of positive and negative electrodes and a separator is housed inside the outer can, the conductive member connected to the electrode of one electrode of the electrode body is sealed while the sealing body is attached to the opening of the outer can. Or a welding step of welding with a terminal disposed on a sealing body, and a method of manufacturing a battery that undergoes a sealing step of sealing an opening of an outer can with a sealing body by caulking,
The conductive member used in the welding step is a current collector made of a plate-like member connected to the one electrode, and is separate from the current collector, and connects the current collector and the terminal. A lead part made of a plate-like member, and the lead part has a flat part in contact with the surface of the current collecting part, and a convex part welded to the sealing body or the terminal,
In the sealing step, the inside of the outer can in the caulking process is pressurized with a sealing body, and the convex portion in the lead portion is compressed and deformed in the thickness direction of the planar portion in accordance with the plane of the planar portion, method for producing a battery according to claim Rukoto contacting parts flush with the surface. In a state in which an electrode body composed of positive and negative electrodes and a separator is housed inside the outer can, the conductive member connected to the electrode of one electrode of the electrode body is sealed while the sealing body is attached to the opening of the outer can. Or a welding step of welding with a terminal disposed on a sealing body, and a method of manufacturing a battery that undergoes a sealing step of sealing an opening of an outer can with a sealing body by caulking,
The conductive member used in the welding step is formed by bending a band-shaped plate material along the width direction, and connecting the one region with the bent portion as a boundary to the one electrode, and the other region with the current region. The lead part is welded to the sealing body or the terminal, and the lead part is connected to the terminal provided at a distance of half or less of the inner diameter of the outer can from the boundary, and the current collecting part from the connection point Having an extension provided in a direction away from
Wherein in the sealing step, the caulking pressurized internal outer can by the compressing the lead portions in the thickness direction of the plate material, a manufacturing method of batteries, characterized in that contacting the collector portion. The battery manufacturing method according to claim 6, wherein, in the welding step, when the extension portion comes into contact with the back surface of the sealing body, the sealing body inside the outer can is supported or positioned by the elastic force of the extension portion. Way .

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