JPH0935701A - Battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery with structure of a number of leads in which a plurality of collecting lead parts are easily connected to an electric conduction member. SOLUTION: A spiral electrode 3 is formed by piling up a belt-like positive electrode plate to which a positive electrode active material adheres, a separator, a belt-like negative electrode plate to which a negative electrode active material adheres and a separator and spirally winding it around a core rod 2 made of an insulating material. A plurality of collecting lead parts 6 projecting on the upper side are integrally provided in the positive electrode plate, and a plurality of collecting lead parts 7 projecting on the lower side are similarly provided in the negative electrode plate. An insulating plate 8 is provided in the upper end surface of the spiral electrode 3, and the round hole of the tip of the collecting lead parts 6 led out through a slit is fitted into the upper end of the core rod 2. An electric conduction member 10 is fitted into and fixed to the upper end part of the core rod 2 by fastening a nut member II. Also, on the lower end surface side of the spiral electrode 3, an insulating plate 9 is provided, and similarly the collecting lead parts 7 are fixed and connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery provided with a spiral electrode in which a strip-shaped electrode plate is wound around a separator in a cylindrical shape.

[0002]

With the spread of portable electric devices such as mobile phones, portable video cameras, and notebook computers in recent years, there is a rapid need for larger capacity batteries and higher energy densities for the power supplies. Is increasing. The success or failure of high energy density in a battery depends on how to obtain a shape and structure that can take a large electrode plate area in a limited volume. As a typical example, a spiral electrode is used. The so-called roll-up type structure is adopted in many batteries.

The spiral-shaped electrode of this type of wound-up type battery is designed to apply a current to the surface of a strip-shaped metal thin plate (or foil) having a high electrical conductivity such as copper or aluminum, which is called a current collector, by a battery reaction. The positive and negative active materials are applied to produce positive and negative electrode plates, respectively, and the positive and negative electrode plates are superposed on each other via a separator and spirally wound. On the other hand, in this type of winding type battery, in order to increase the capacity, in order to increase the capacity and lower the resistance of the current path so as to withstand a high load and a large current, the leads are connected to each electrode plate. A multi-lead structure has been considered which is derived from multiple points in the longitudinal direction. In this case, the leads are integrated inside the battery and connected to the electrode terminals outside the container via the conductive member.

However, in the above-mentioned multi-lead structure, a plurality of leads must be gathered and connected to a conductive member in a limited narrow space inside the battery, and the work is considerably difficult. There is also a possibility that internal shunt may occur due to contact with the opposite electrode due to slack of the lead or the like.

Therefore, as a method for solving the problem, in Japanese Utility Model Publication No. 57-1402, a relay plate made of nickel is provided on the end face of the spiral electrode via an insulating plate.
A technique of welding a plurality of leads, which are led out through arcuate slits formed in the insulating plate and the relay plate, to the upper surface of the relay plate is shown. According to this, each lead can be easily welded to the relay plate, and there is no possibility of causing an internal short circuit due to the insulating plate. However, in this technique, since welding is performed near the end surface of the spiral electrode,
There was a problem that the insulating plate was melted by the heat at that time or the heat was transmitted to the leads and damaged the separator.

The lead is generally provided on the electrode plate (current collector) by welding. Since the thickness of the welded portion is not uniform, the lead is damaged and the current is concentrated on a part of the lead. As a result, abnormal deposition of the active material may occur, resulting in a short circuit. Particularly, in the case where lithium metal is used for the negative electrode, needle-like deposits called dendrites are generated due to current concentration, which may cause cycle deterioration and internal short circuit.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a so-called multiple lead structure in which a plurality of current collecting lead portions are electrically connected for external connection without using welding. It is an object to provide a battery that can be easily connected to a member.

[0008]

The battery according to claim 1 of the present invention is a spiral in which a strip-shaped electrode plate coated with a positive or negative active material on its surface is wound in a cylindrical shape through a separator. In which a spiral electrode is provided to collect current from multiple points of the spiral electrode, the strip-shaped electrode plate projects in the axial direction of the spiral electrode from an edge portion extending in the longitudinal direction. A plurality of current collecting lead portions are provided intermittently, and the plurality of current collecting lead portions are fixed in a locked state on an insulative mandrel arranged at the center of the spiral electrode. Is characterized in that it is connected to a conductive member for external connection.

In this case, it is effective if an insulating plate having a slit through which the current collecting lead portion is inserted is provided in the end face portion of the spiral electrode in a penetrating state of the mandrel (invention of claim 2). . At this time, a plurality of slits of the insulating plate may be formed in an arc shape (the invention of claim 3) or may be formed in a spiral shape (the invention of claim 4).

The current collecting lead portion can be formed integrally with the electrode plate (invention of claim 5), and at this time, the portion connecting from the electrode plate to the current collecting lead portion is curved. If configured, it is more effective (the invention of claim 6). Further, the projecting length of the current collecting lead portion may be smaller as it is located closer to the center of winding of the spiral electrode and larger as it is located closer to the outer circumference of the spiral (the invention of claim 7).

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG.
The internal structure of the battery 1 according to the present embodiment is shown. Here, as shown in FIG. 2, the battery 1 has, for example, a cylindrical electrode (winding electrode) 3 wound in a cylindrical shape around a mandrel 2 in a case (not shown) having a cylindrical shape. Is configured. Although not shown, the case is also provided with positive and negative electrode terminals.

The mandrel 2 is formed of an insulating material such as plastic such as polypropylene or ceramics into a hollow round bar shape, and has a length such that the upper and lower ends thereof protrude from the spiral electrode 3. . The upper and lower ends of the mandrel 2 are formed to have a diameter slightly smaller than that of the portion around which the spiral electrode 3 is wound, and are formed as male screw portions 2a and 2b having male screws.

The spiral electrode 3 is a positive electrode plate 4
(See FIG. 3), a separator, a negative electrode plate, and a separator (the latter three members are not shown) are superposed and spirally wound around the mandrel 2. Among them, as shown in FIG. 3, the positive electrode plate 4 is formed by applying a positive electrode active material 5 (shown by hatching in FIG. 3 for convenience) on the surface of a strip-shaped thin metal plate (current collector), applying pressure or the like. It is composed by being attached.

In this case, as the metal thin plate (current collector),
For example, a highly conductive material such as aluminum or copper is used, and as the positive electrode active material 5, for example, lithium manganese oxide or lithium cobalt oxide is used. Further, in this case, the thickness of the thin metal plate is about several μm to several tens of μm, the width is about several cm to several tens of cm, and the length is about 1 to 10 m.

As shown in FIG. 2, the positive electrode plate 4 is provided with a plurality of current collecting lead portions 6 integrally with the thin metal plate in this case. These current collecting lead portions 6
Are formed intermittently (for example, at equal intervals) in the length direction of the positive electrode plate 4 so as to project upward from the upper edge portion of the positive electrode plate 4 in the figure, and the tip portion thereof is Mandrel 2
A circular hole 6a having a diameter slightly larger than the outer diameter of the male screw portion 2a is formed.

Further, the current collecting lead portion 6 has a projecting length dimension that is shorter as it is located closer to the winding center side (left side in FIG. 3) of the spiral electrode 2 and is closer to the winding outer peripheral side (right side in FIG. 3). )
It is formed so that it becomes longer as it goes to. Further, in the present embodiment, the inner corner portion 6b of the root connecting from the positive electrode plate 5 to the current collecting lead portion 6 is curved (R
Shape). The pitch, the number, etc. of the current collecting lead portions 6 are set based on the total length of the electrode plate 4, the target battery performance, and the like.

On the other hand, the negative electrode plate is formed by depositing a negative electrode active material on the surface of a strip-shaped metal thin plate (collector) made of aluminum or copper. in this case,
The negative electrode active material is composed of metallic lithium or an alloy thereof, or a material capable of occluding lithium ions (carbon or graphite). Also, the dimensions of the thin metal plate are
It is equivalent to the positive electrode plate 5.

The negative electrode plate is also integrally provided with a plurality of current collecting lead portions 7 (shown only in FIG. 1). These current collecting lead portions 7 are provided intermittently so as to project downward from the lower edge portion in the figure of the negative electrode plate, and although not shown in detail, like the positive electrode plate 5, the tip portion is provided at the tip portion. A circular hole having a diameter slightly larger than the outer diameter of the male screw portion 2b of the mandrel 2 is formed. Further, the projecting length dimension of these current collecting lead portions 7 is formed so as to be shorter toward the winding center side of the spiral electrode 2 and longer toward the winding outer peripheral side. The inner corner portion of the root connected to the electric lead portion 7 is curved.

The two separators are both made of PP.
It is made of a material having fine pores containing an electrolytic solution and allowing the passage of ions, such as a non-woven fabric and a non-woven fabric, and has a thickness dimension of several tens of μm and a width dimension of the positive electrode plate 5 (metal thin plate). It is several mm longer than the dimension, and the length dimension is the positive electrode plate 5
It is formed to be several cm to several tens of cm longer than the length dimension of.

Thus, in the spiral electrode 3 in which the positive electrode plate 4, the separator, the negative electrode plate and the separator are superposed and wound, as shown in FIG. The current collecting lead portions 6 of the book are projected, and the plurality of current collecting lead portions 7 are projected from the lower end surface portion.

Insulating plates 8 and 9 are provided on the upper and lower end surfaces of the spiral electrode 3 having the above-described structure. In FIG. 4, the insulating plate 8 is shown as a representative of these, and these insulating plates 8 and 9 are made of an insulating material such as plastic such as polypropylene or ceramics, and are thin circles having substantially the same diameter as the spiral electrode 3. It has a plate shape. Further, on the plate surface, a central hole 8a located at the center and through which the mandrel 2 penetrates,
9a is formed, and a plurality of arcuate slits 8b, 9b are formed substantially concentrically around it.

As shown in FIG. 2A, the insulating plate 8 is provided so as to cover the upper end surface portion of the spiral electrode 3. At this time, the upper end portion of the mandrel 2 (the male screw portion 2
a) penetrates through the central hole 8a of the insulating plate 8 and is located on the upper surface of the insulating plate 8, and the plurality of current collecting lead portions 6 are inserted through the arcuate slits 8b to form the upper surface of the insulating plate 8. Is located in.

As shown in FIG. 2B, the plurality of current collecting lead portions 6 located on the upper surface of the insulating plate 8 have their circular holes 6a fitted into the male screw portions 2a of the mandrel 2. By inserting it, the mandrel 2 is brought into a state of being locked to the mandrel 2 so that the mandrel 2 is put in a state of being overlapped at one place. In this case,
For example, the current collecting lead portions 6 located on the inner peripheral side are sequentially fitted into the male screw portions 2a.

Further, from this state, the terminal portion 10a of the conductive member 10 for external connection is fitted into the male screw portion 2a of the mandrel 2, and then the nut member 11 is tightened to the male screw portion 2a. Thus, the upper end of the mandrel 2 functions as a terminal, so to speak, and the plurality of current collecting lead portions 6 and the conductive member 10 are fixed to the upper end of the mandrel 2 in an electrically connected state. The other end of the conductive member 10 is connected to the positive electrode terminal of the battery 1.

On the other hand, as shown in FIG. 1, also on the lower end surface side of the spiral electrode 3, in the same manner, the insulating plate 9 has a plurality of current collecting leads in which the lower end of the mandrel 2 penetrates the center hole 9a. The portion 7 is provided so as to be inserted into the slit 9b, the plurality of current collecting lead portions 7 are fitted and inserted into the male screw portion 2b of the mandrel 2 to be in a locked state, and the conductive member 12 is further stacked. Is fixed by tightening the nut 13. The conductive member 12 is connected to the negative electrode terminal of the battery 1.

In the battery 1 configured as described above, the area of the electrode plate can be made extremely large in a limited volume by having the spiral electrode 3, so that the capacity and the energy density can be increased. Can be achieved,
Further, at this time, by deriving the current collecting lead portions 6 and 7 from multiple points, it is possible to increase the capacity and the resistance of the current path.

In this embodiment, the mandrel 2 having an insulating property is provided at the center of the spiral electrode 3, and the current collector leads 6 and 7 are fixed to the ends of the mandrel 2 in a locked state. Therefore, the mandrel 2 plays a role as a terminal so to speak, and the plurality of current collecting lead portions 6 and 7 can be easily connected to the conductive member 1.
0,12 can be connected. In this case, unlike the conventional one in which a plurality of leads are welded to a metal relay plate, the welding itself is not necessary, so the heat at that time causes the insulating material (insulating plates 8 and 9 and the separator) to It is possible to prevent adverse effects.

Further, since the insulating plates 8 and 9 are provided on the end surface portion of the spiral electrode 3 and the connection of the current collecting lead portions 6 and 7 is made on the outer surface side thereof, the end surface portion of the spiral electrode 3 is The collecting lead portions 6 and 7 are insulating plates 8 and
It is possible to prevent an internal short circuit from occurring by separating the current collecting lead portions 6 and 7 from each other by contacting the opposite poles at the end faces.

In this case, since a large number of arcuate slits 8b and 9b are formed in the insulating plates 8 and 9,
The current collecting lead portions 6 and 7 can be led out to the outside through arbitrary slits 8b and 9b corresponding to their positions, and the work can be easily performed. Furthermore, since the insulating plates 8 and 9 regulate the bending of the current collecting lead portions 6 and 7, it is possible to prevent the bending of the root portions of the current collecting lead portions 6 and 7 and the damage thereof. .

Further, particularly in this embodiment, since the current collecting lead portions 6 and 7 are integrally provided on the electrode plate (current collector), it is possible to provide separate leads by welding on the electrode plate. There is no unevenness in the thickness of the electrode plate,
It is possible to prevent damage to the separator and abnormal deposition of the active material due to the uneven thickness. At this time, since the inner corner portion 6b of the root extending from the electrode plate 5 to the current collecting lead portion 6 is formed in a curved shape, a crack may occur at that portion as in the case of having a right angled corner portion, for example. Is something that disappears.

Moreover, in this embodiment, the current collecting lead portions 6,
Since the projecting length of 7 is smaller toward the winding center of the spiral electrode 3 and larger toward the outer circumference of the spiral electrode 3, the projecting length of each of the current collecting lead portions 6 and 7 is set to the mandrel. It is possible to correspond to the distance up to 2, and the slack state of the current collecting lead portions 6 and 7 up to the mandrel 2 is made uniform, so that the fixing work to the mandrel 2 can be performed more easily. It becomes.

As described above, according to this embodiment, a so-called multi-lead structure is provided, and a plurality of current collecting lead portions 6 and 7 are connected to the conductive member 1 for external connection without using welding.
It is possible to easily connect to 0 and 12, and it is possible to obtain an excellent practical effect that the capacity and the resistance of the current path can be increased in a limited volume. is there.

In the above embodiment, the circular hole 6a is formed at the tip of the current collecting lead portion 6 and is inserted into the mandrel 2 so as to be in the locked state. As shown in an electrode plate 17 of another embodiment of the invention, a current collecting lead portion 18
It is also possible to form a U-shaped cutout portion 18a at the tip end portion of the above and insert the portion into the mandrel 2 from the outer peripheral side so as to be in a locked state.

FIG. 6 shows an insulating plate 21 according to another embodiment of the present invention. The insulating plate 21 is also made of an insulating material in a disk shape, and is provided only in a portion through which the current collecting lead portion is inserted (a portion in which the current collecting lead portion is led out from the end surface portion of the spirally wound spiral electrode). The slit 21a is formed in advance at the position. In addition, FIG. 7 shows an insulating plate 22 according to still another embodiment. Here, the slit 22a is formed in a spiral shape, and the current collecting lead portion is led out from an arbitrary position thereof. .

Besides, the present invention is not limited to the above-mentioned respective embodiments, and the following expansions and changes can be made, for example. That is, in the above embodiment, the nut member is fastened to the male screw portion of the mandrel to connect the current collecting lead portion and the conductive member, but an E ring is used for the connection (fixing means) other than the nut. Various means such as crimping can be considered. At this time, as long as there is no adverse effect from heat, welding or brazing (soldering)
Etc. may be used.

Further, the current collecting lead portion is not limited to being integrally formed on the electrode plate, but a separate current collecting lead portion may be welded or brazed so that the thickness is not uniform. If the problem is not so important, the method of welding a separate current collecting lead portion is relatively easier to manufacture the electrode plate. Further, the material and dimensions of the electrode plate (current collector), positive and negative active materials, separators and the like can be variously changed and implemented.

[0037]

According to the battery of claim 1 of the present invention, a plurality of current collecting lead portions which are led out in the axial direction at the end face portion of the spiral electrode are arranged at the center of the spiral electrode as a terminal. It is fixed to the mandrel which plays a role of and is connected to the conductive member. Therefore, in a so-called multi-lead structure, it is possible to easily connect a plurality of current-collecting lead portions to a conductive member for external connection without using welding, and thus, within a limited volume. It is possible to obtain an excellent practical effect that the current path can have a large capacity and a low resistance.

In this case, an insulating plate having a slit through which the current collecting lead portion is inserted is provided in the end face portion of the spiral electrode in a penetrating state of the mandrel (battery of claim 2). Since the tip end side portion of the portion and the end surface of the spiral electrode are separated by the insulating plate, it is possible to prevent the occurrence of internal short circuit due to contact with the opposite electrode. At this time, a plurality of slits of the insulating plate may be formed in an arc shape (the battery of claim 3) or may be formed in a spiral shape (the battery of claim 4). The current collecting lead portion can be easily led out.

If the current collecting lead portion is integrally formed with the electrode plate (battery of claim 5), the thickness of the electrode plate is different from the case where the current collecting lead portion is welded to the electrode plate as a separate body. It is not uniform, and it is possible to prevent damage to the separator and abnormal deposition of the active material due to uneven thickness. At this time, if there is a right angled portion in the portion connecting from the electrode plate to the current collecting lead portion, for example, there is a fear that cracks may occur at that portion, but this portion should be curved. If constituted (battery of Claim 6), generation | occurrence | production of such a crack can be prevented beforehand.

Further, the projecting length dimension of the current collecting lead portion may be made smaller toward the winding center side of the spiral electrode and larger toward the winding outer circumference side (battery of claim 7). The projecting length of each current collector lead can be made to correspond to the distance to the mandrel, and the slack state of each current collector lead up to the mandrel is made uniform, making it easier to fix to the mandrel. You will be able to do it.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is a vertical cross-sectional view of the inside of a battery.

FIG. 2 is a perspective view showing a part of a battery assembling process.

FIG. 3 is a plan view of a positive electrode plate.

FIG. 4 is a plan view of an insulating plate.

FIG. 5 is a plan view of an essential part of an electrode plate showing another embodiment of the present invention.

FIG. 6 is a plan view of an insulating plate according to another embodiment.

FIG. 7 is a plan view of an insulating plate showing still another embodiment.

[Explanation of symbols]

In the drawing, 1 is a battery, 2 is a mandrel, 3 is a spiral electrode,
4, 17 are electrode plates, 5 is an active material, 6, 7 and 18 are current collecting lead portions, 6a are circular holes, 8, 9, 21, 22 are insulating plates, 8b, 9b, 21a and 22a are slits, 10 ，
Reference numeral 12 represents a conductive member.

Claims (7)

[Claims] 1. A spirally wound electrode comprising a strip-shaped electrode plate having a positive or negative active material coated on the surface thereof and having a separator interposed between the spirally wound electrode plate and the spirally wound electrode plate. In the belt-shaped electrode plate, a plurality of current collecting lead portions projecting in the axial direction of the spiral electrode from the edge portion extending in the longitudinal direction thereof are intermittently provided, The plurality of current-collecting lead portions are fixed in a locked state on an insulative mandrel arranged at the center of the spiral electrode, and the mandrel portion is connected to a conductive member for external connection. A battery characterized in that. 2. The battery according to claim 1, wherein an insulating plate having a slit through which a current collecting lead portion is inserted is provided in an end face portion of the spiral electrode in a penetrating state of a mandrel. 3. The battery according to claim 2, wherein the slit of the insulating plate has a circular arc shape and a plurality of slits are formed. 4. The battery according to claim 2, wherein the slit of the insulating plate is formed in a spiral shape. 5. The battery according to claim 1, wherein the current collecting lead portion is formed integrally with the electrode plate. 6. The battery according to claim 5, wherein a portion connecting from the electrode plate to the current collecting lead portion is configured to have a curved shape. 7. The projecting length dimension of the current collecting lead portion is smaller as it is located closer to the winding center of the spiral electrode, and is larger as it is located closer to the outer circumference of the spiral electrode. 7. The battery according to any one of 1 to 6.