JPH11162521A - Cylindrical lithium secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small cylindrical lithium secondary battery, which a winding electrode body is contained in a battery jar, an electrode terminal mechanism is attached to a lid body of the battery jar, and the winding electrode body and the electrode terminal mechanism is connected each other by means of a plurality of current collecting tabs, that can connected the current collecting tabs easily with a large strength and liability to the electrode terminal mechanism and that has small resistance at the connected part. SOLUTION: An electrode terminal mechanism 4 is fixed to a lid body 12 passing through a through hole provided on the lid body 12 in a state that electrical insulating and liquid-tight is kept against the lid body 12. A clamping nut 54 is provided on a tip end part of the electrode terminal mechanism 4, and the other hand, a clamping pressure plate 51 and clamping pressure receiving plate 6 that generate clamping pressure by screwing in the clamping nut 54 are provided its base part. Tip end parts 31 of a plurality of current collecting tabs 3 are imposed between the clamping pressure plate 51 and the clamping pressure receiving plate 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention allows a wound electrode body to be housed inside a cylindrical battery can and to take out the power generated by the wound electrode body from an electrode terminal mechanism attached to the battery can. The present invention relates to a simple cylindrical lithium secondary battery.

[0002]

2. Description of the Related Art In recent years, lithium secondary batteries which have a high energy density and do not contain harmful substances such as cadmium and lead have been attracting attention as power sources for portable electronic devices, electric vehicles, road leveling and the like. For example, as shown in FIGS. 7 and 8, a relatively large capacity cylindrical lithium secondary battery used in an electric vehicle has lids at both ends of a cylindrical body (11).
(12) The wound electrode body (2) is accommodated in a cylindrical battery can (1) formed by welding and fixing (12). A pair of positive and negative electrode terminal mechanisms (9) and (9) are attached to the lids (12) and (12), and the take-up electrode body (2) and the two electrode terminal mechanisms (9) and (9) are attached. Are connected to each other by a plurality of current collecting tabs (3), so that the electric power generated by the winding electrode body (2) can be taken out from the pair of electrode terminal mechanisms (9) (9). . Further, a safety valve (13) is attached to the lid (12).

[0003] As shown in FIG. 9, the winding electrode body (2)
A positive electrode (21) containing a lithium composite oxide, a separator (22) impregnated with a non-aqueous electrolyte, and a negative electrode (23) containing a carbon material are overlapped, and these are spirally wound. I have. A plurality of current collecting tabs (3) are respectively drawn from the positive electrode (21) and the negative electrode (23), and a plurality of current collecting tabs (3) having the same polarity are provided.
Are connected to one electrode terminal mechanism (9). In FIG. 9, for convenience, only a state in which the tip of a part of the current collecting tabs is connected to the electrode terminal mechanism (9) is shown.
The illustration of the state connected to (9) is omitted. The electrode terminal mechanism (9) includes a screw member (91) attached through the lid (12) of the battery can (1), and a flange (92) is provided at the base end of the screw member (91). ) Is formed. An insulating packing (93) is attached to the through hole of the lid (12), and the lid (12) and the fastening member
Electrical insulation and sealing between (91) are maintained. A washer (94) is fitted into the screw member (91) from outside the cylindrical body (11), and a first nut (95) and a second nut (96) are screwed together. Tighten these nuts (95) (96)
By sealing the insulating packing (93) between the flange (92) of the screw member (91) and the washer (94), the sealing property is enhanced. The tips (31) of the plurality of current collecting tabs (3) are fixed to the flange (92) of the screw member (91) by spot welding or ultrasonic welding.

In the manufacturing process of the cylindrical lithium secondary battery, an electrode terminal mechanism (9) is attached to a lid (12) constituting a battery can (1), and is wound inside a cylindrical body (11). With the take-up electrode body (2) inserted, the tips (31) of the plurality of current collecting tabs (3) extending from the take-up electrode body (2) are connected to the flange (92) of the electrode terminal mechanism (9). And finally the lid (12) is attached to the cylinder (1
Both were fixed by welding over the opening of 1).

[0005]

However, in order to increase the capacity of a cylindrical lithium secondary battery, a current collecting tab is required.
If the number of (3) is small, the electric resistance is increased and the battery performance is reduced.
According to (3), the winding electrode body (2) and the electrode terminal mechanism (9)
Need to be connected.

However, it is difficult to weld a plurality of current collecting tabs (3) to the flange (92), and it takes at least several tens of minutes. The current collecting tab (3) has a thickness of 0.1.
mm or a foil body made of nickel or nickel, the welded portion may be melted and a hole may be formed. As a result, there is a problem that the connection strength of the current collecting tab (3) is significantly reduced. Was. Even when normal welding is performed without forming a hole, a large connection strength cannot be obtained because the area of the welding portion between the current collecting tab (3) and the flange (92) is extremely small. Of course, there is a problem that electric resistance is remarkably increased at a welding portion between the current collecting tab (3) and the flange portion (92), so that resistance heat is generated.

[0007] An object of the present invention is to provide a cylindrical lithium secondary battery in which a current collecting tab can be easily connected to an electrode terminal mechanism with high strength and reliability, and the electrical resistance at the connecting portion is small. That is.

[0008]

A cylindrical lithium secondary battery according to the present invention includes a battery can (1) having a lid (12) fixed to an opening of a cylindrical body (11). The wound electrode body (2) is housed inside (1). Winding electrode body (2)
A positive electrode (21) containing a lithium composite oxide, a separator (22) impregnated with a non-aqueous electrolyte, and a negative electrode (2
3) is superposed and spirally wound. An electrode terminal mechanism (4) is attached to the lid (12) of the battery can (1), and the winding electrode body (2) and the electrode terminal mechanism (4).
Are connected to each other by a plurality of current collection tabs (3),
The power generated by the winding electrode body (2) is transferred to the electrode terminal mechanism (4).
It is possible to take out from outside.

In the cylindrical lithium secondary battery according to the present invention, the electrode terminal mechanism (4) is provided with a through hole formed in the lid (12).
(14), and is fixed to the lid (12) while maintaining electrical insulation and liquid tightness with respect to the lid (12), and a tip end protruding outside the lid (12). In the meantime, a clamping nut (54) is provided, while a base end protruding inside the lid (12) is provided with a clamping plate (5) which exerts a clamping force by screwing the clamping nut (54).
1) and a pressure receiving plate (6). The distal ends of the plurality of current collecting tabs (3) are pressed with a pressure plate (51) and a pressure receiving plate.
(6) and is connected to the electrode terminal mechanism (4). Each of the current collecting tabs (3) is formed of a strip-shaped foil having conductivity. Also, the pressure plate (51) and the pressure receiving plate
(6) has a sufficient squeezing area necessary for securely holding the tips of the plurality of current collecting tabs (3).

In the cylindrical lithium secondary battery of the present invention, the tips of the plurality of current collecting tabs (3) are sandwiched between the pressure plate (51) and the pressure receiving plate (6), and the electrode is formed. Because it is connected to the terminal mechanism (4), the current collecting tab
The work of welding the tip of (3) to the electrode terminal mechanism (4) is unnecessary, and simply the tip of the plurality of current collecting tabs (3) is pressed.
(51) and the pressure receiving plate (6).
, The tips of the plurality of current collecting tabs (3) are simultaneously pressed by the pressing plate (51) and the pressing receiving plate (6),
Connection work is completed. In a state where the tip portions of the plurality of current collecting tabs (3) are sandwiched between the pressure plate (51) and the pressure receiving plate (6),
The tip of each current collecting tab (3) comes into contact with the pressure plate (51) and the pressure receiving plate (6) with a sufficient area, and due to this sufficient contact area, the electric resistance at the connection portion becomes small, and at the same time, High connection strength is obtained. Since the conventional welding structure is not used in the connection structure by the pinching pressure, the current collecting tab (3) does not have a hole, and high reliability can be obtained.

In a specific configuration, the electrode terminal mechanism (4)
Is inserted through the through hole (14) opened in the lid (12), and the lid (1
2) A screw portion (71) is provided at the tip protruding outside, and a flange portion (72) is provided at the base end protruding inside the lid (12).
A fastening nut (73) that is screwed into a screw portion (71) of the fastening member (7) to fix the fastening member (7) to the lid (12); It is attached to the through hole (14) of the lid (12),
It is interposed between the lid (12) and the fastening member (7), and is sandwiched between the flange portion (72) of the fastening member (7) and the fastening nut (73), so that the fastening member (7) and the lid (12) An insulating packing (8) (81) for maintaining electrical insulation and liquid tightness between the shaft and a shaft (50) inserted through a central hole (75) opened in the fastening member (7); A screw portion (53) is formed at the distal end of the shaft portion (50) protruding outside the (12), and is formed at the base end of the shaft portion (50) protruding inside the lid (12). Is a pressing member to which the pressing plate (51) is fixed.
(5), wherein the pinching nut (54) is screwed into a screw portion (53) of the pinching member (5), and the pinching receiving plate (6) is a shaft portion (5) of the pinching member (5). It is loosely fitted to 50) and is interposed between the pressing plate (51) and the flange portion (72) of the fastening member (7).

In the above specific configuration, before fixing the lid (12) to the cylinder (11), the insulating packings (8) and (81) are attached to the through holes (14) of the lid (12). At the same time, the fastening member (7) is inserted. As a result, the fastening member (7) is provided outside the lid (12).
A screw portion (71) formed at the tip end of the projection protrudes. Therefore,
A fastening nut (73) is screwed into the screw portion (71) and tightened. As a result, the insulating packings (8) and (81)
It is sandwiched between the flange portion (72) and the fastening nut (73) of (7), and is pressed, and the fastening member (7) is securely fixed to the lid (12). In this state, sufficient electrical insulation and liquid tightness are maintained between the lid (12) and the fastening member (7). Then, the pressure receiving plate is attached to the shaft portion (50) of the pressure pressing member (5).
(6), and fix the shaft portion (50) of the clamping member (5) to the fastening member.
A plurality of current collecting tabs (3) extending from the winding electrode body (2) are inserted between the pressure receiving plate (6) and the pressure pressing plate (51) while being inserted into the central hole (75) of (7). Insert the tip. In this state, the screw portion (5) of the pressing member (5) projecting outward from the fastening member (7) is
Screw the clamping nut (54) into 3) and tighten. As a result, the distal ends of the plurality of current collecting tabs (3) are
The pressing plate (51) and the pressing receiving plate (6) of (5) surely hold the plate. Finally, the lid (12) is fixed to the cylinder (11) to complete the cylindrical lithium secondary battery.

As described above, first, the fastening member (7) is attached to the lid (12).
After the work for providing sufficient electrical insulation and liquid tightness between the lid (12) and the fastening member (7), the clamping member (5) is attached to the fastening member (7). And the pressure plate (51) and the pressure receiving plate
Since the work of clamping the tips of the plurality of current collection tabs (3) is performed between (6), both work are separated, and the electrical insulation and liquid tightness achieved in the previous work are There is no danger of being changed by the later work, and conversely, the connection strength of the current collecting tab (3) realized by the later work may be changed by re-adjustment of the tightening force of the fastening member (7). There is no.

In a more specific configuration, the pressing plate (51) of the pressing member (5) has a pressing force for tightening the pressing nut (54) on a surface facing the winding electrode body (2). A prismatic piece (52) to be used for preventing the member (5) from rotating is protruded. According to this specific configuration, when the clamping nut (54) is tightened by the tool, an appropriate tool is also engaged with the prism piece (52) to prevent the clamping member (5) from rotating together. Since it is possible, the tightening work of the clamping nut (54) is easy, and the tightening can be surely performed.

In a more specific configuration, inside the battery can (1), between the opposing surfaces of the lid (12) and the insulating packing (8), and between the insulating packing (8) and the flange portion (7) of the fastening member (7). O-rings (82), (83), (84) are interposed between the opposing surfaces of the clamping member (7) and between the opposing surfaces of the flange portion (72) of the fastening member (7) and the pressure receiving plate (6), respectively. . According to this specific configuration, between the lid (12) and the insulating packing (8), between the insulating packing (8) and the flange portion (72) of the fastening member (7), and between the lid (12) and the flange portion (72) of the fastening member (7). Department (7
Higher liquid tightness can be obtained between 2) and the pressure receiving plate (6).

[0016]

In the cylindrical lithium secondary battery according to the present invention, a pressure plate (51) and a pressure receiving plate are used as a structure for connecting a plurality of current collecting tabs (3) to the electrode terminal mechanism (4). Since the structure in which the front end of each current collecting tab (3) is simply sandwiched between (6) is adopted, the conventional welding work is unnecessary and the connection work is easy. Also, there is no hole in the current collecting tab (3) due to the connection work, and the current collecting tab (3) is held between the pressure plate (51) and the pressure receiving plate (6) with a sufficient contact area. High connection strength and high reliability can be obtained. Further, the electric resistance of the connection portion is small, and the problem of resistance heat generation does not occur.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. As shown in FIG. 2, the cylindrical lithium secondary battery according to the present invention has a cylindrical battery can formed by welding and fixing lids (12) and (12) to both ends of a cylindrical body (11).
A pair of positive and negative electrode terminal mechanisms (4) and (4) are attached to both lids (12) and (12). Further, a safety valve (13) is attached to each lid (12).

A wound electrode body (2) shown in FIG. 4 is housed inside the battery can (1). Winding electrode body (2)
A positive electrode (21) containing a lithium composite oxide, a separator (22) impregnated with a non-aqueous electrolyte, and a negative electrode (2
3) is superimposed, and these are spirally wound. The base ends of a plurality of current collecting tabs (3) are respectively joined to the positive electrode (21) and the negative electrode (23) by spot welding or the like, and the front ends protrude from the winding electrode body (2).
The current collecting tab (3) joined to the positive electrode (21) is made of aluminum foil, and the current collecting tab (3) joined to the negative electrode (23) is made of nickel foil.

A pair of positive and negative electrode terminal mechanisms (4) shown in FIG.
Of (4), a plurality of current collection tabs (3) drawn from the positive electrode (21) are connected to one electrode terminal mechanism (4) serving as a positive electrode terminal, and the other electrode terminal mechanism (4) serving as a negative electrode terminal. Electrode terminal mechanism
A plurality of current collection tabs (3) drawn from the negative electrode (23) are connected to (4). As a result, the electric power generated by the winding electrode body (2) is transferred to a pair of positive and negative electrode terminal mechanisms.
(4) It can be taken out from (4).

As shown in FIG. 3, the lid (12) has a through hole (14) at the center and a screw hole (15) at the outer periphery, and the through hole (14) has an electrode terminal. The mechanism (4) is attached,
A safety valve (13) is attached to the screw hole (15). The electrode terminal mechanism (4) has a structure shown in FIGS. As shown in FIG. 1, a pair of insulating packings (81) and (8) are fitted into the through holes (14) of the lid (12) in a state where they are engaged with each other. As shown in FIG. 3, the lower insulating packing (8) is a disc
(85) and the cylindrical portion (86), while the upper insulating packing (81) is formed in a ring shape and engages with each other so that the inner periphery of the through hole (14) of the lid (12) is formed. It can adhere to the surface and the inner peripheral edge.

In the through hole (14) of the lid (12), a fastening member (7)
Is inserted from the inside of the lid (12). The fastening member (7) integrally includes a screw portion (71) that is to protrude outside the lid (12) and integrally includes a flange portion (72) that protrudes inside the lid (12). I have. A large-diameter O-ring (82) is interposed between the facing surface of the lid (12) and the disk (85) of the insulating packing (8), and fastened to the disk (85) of the insulating packing (8). A small-diameter O-ring (83) is interposed between the opposing surfaces of the flange portion (72) of the member (7). The screw portion (7) of the fastening member (7) protruding outside the lid (12)
A first fastening nut (73) and a second fastening nut (74) are screwed into 1) via a washer (61).

The pressing member (5) is inserted into the center hole (75) of the fastening member (7) from the inside of the lid (12). Nipping member
(5) has a shaft portion (50) penetrating the fastening member (7), and a screw projecting from the fastening member (7) to the outside of the lid (12) is provided at the tip of the shaft portion (50). A part (53) is formed. On the other hand, the shaft (5
A circular pressure plate (51) is fixed to the base end of (0), and a prismatic piece (52) is integrally protruded from the back surface of the pressure plate (51). A circular pressure receiving plate is provided on the shaft portion (50) of the pressing member (5).
(6) is loosely fitted. Flange part (72) of fastening member (7)
And a small-diameter O-ring (84) between the opposing surfaces of the pressure receiving plate (6).
Intervenes. The shaft (50) of the clamping member (5) is a clamping plate (6)
And through the central hole (75) of the fastening member (7),
The pinching nut (54) is screwed into the screw portion (53) protruding outward from the nut.

As shown in FIG. 1, a plurality of current collecting tabs (3) extending from the winding electrode body (2) have a distal end portion which is a pressing member.
(5) sandwiched between the pressure plate (51) and the pressure receiving plate (6),
It is connected to the electrode terminal mechanism (4). In FIG. 1, for convenience, only a part of the current collecting tabs (3) is connected to the electrode terminal mechanism.
(4) is shown, and the other current collecting tabs (3) are not shown at the tip, but all current collecting tabs (3) have pressure plates ( 51) and the pressure receiving plate (6), and are connected to the electrode terminal mechanism (4).
Here, the pressure plate (51) and the pressure receiving plate (6) are formed in a size necessary to securely hold the distal end portions (31) of the plurality of current collecting tabs (3). It has a pinching area.

The mounting of the electrode terminal mechanism (4) and the connection of the current collecting tab (3) are performed in the order shown in FIGS. First, as shown in FIG. 5A, a fastening member (7) is fixed to one lid (12) using a first fastening nut (73) and a second fastening nut (74). At this time, as shown in FIG. 1, the insulating packings (8) and (81) are connected to the flange portion (72) of the fastening member (7) by the first
The first fastening nut (73) is screwed in until it is nipped by the fastening nut (73) and sufficient liquid tightness is obtained. Meanwhile, the cylindrical body
(11) accommodates the wound electrode body (2) as shown in FIG. 5 (b).

Thereafter, as shown in FIG. 3C, the tip portions of a plurality of current collecting tabs (3) pulled out from the winding electrode body (2).
(31) is sandwiched between the pressure plate (51) of the pressure member (5) and the pressure receiving plate (6). At this time, the tip portions (31) of the current collecting tabs (3) are sandwiched between the pressure plate (51) and the pressure receiving plate (6) without overlapping each other and with a contact area as large as possible. It is desirable to arrange the tip (31) of each current collection tab (3).

In this state, as shown in FIG.
A fastening member in which the shaft (50) of (5) is fixed to the lid (12)
(7) into the center hole (75), and screw the nut (5)
4) Screw together and tighten. At this time, each collecting tab
The tip (31) of (3) is pressed by the pressing plate (51) of the pressing member (5) and the pressing receiving plate (6), and the pressing nut (54) is pressed until sufficient connection strength is obtained. Screw. As a result, FIG.
As shown in (1), the cylindrical body (11) and the lid (12) are connected to each other via the current collecting tab (3). The electrode terminal mechanism (4) is fixed to the other lid (12) in the same manner.

Thereafter, as shown in FIG. 6 (b), the two lids (12) and (12) are joined and fixed to the cylinder (11) using laser welding or beam welding. Finally, after injecting the electrolyte into the battery can (1), a safety valve (13) is attached to each lid (12), and the battery can (1)
To seal. As a result, the cylindrical lithium secondary battery shown in FIGS. 1 to 3 is completed.

As described above, in the cylindrical lithium secondary battery according to the present invention, the current collecting tab (3) is connected to the electrode terminal mechanism (4).
In the step of connecting the current collecting tabs, the conventional welding work is unnecessary, and the tip portions (31) of the plurality of current collecting tabs (3) are simply placed between the pressure plate (51) and the pressure receiving plate (6). Insert the pinching nut (5
Since it is sufficient to screw in 4), the operation is simple, and there is no hole in the current collecting tab 3 so that high reliability can be obtained. In addition, since the tip portion (31) of each current collection tab (3) is sandwiched between the pressure plate (51) and the pressure receiving plate (6) with a sufficient contact area,
The electrical resistance at the contact portion is small, and a high connection strength can be obtained.

Further, in the electrode terminal mechanism (4),
The fastening structure by the fastening member (7) and the clamping structure by the clamping member (5) are separated, and first the fastening member (7) is attached to the lid (12).
After the work for providing sufficient electrical insulation and liquid tightness between the lid (12) and the fastening member (7), the clamping member (5) is attached to the fastening member (7). And the pressure plate (51) and the pressure receiving plate
Since the work of clamping the tip portions (31) of the plurality of current collecting tabs (3) can be performed between (6), the electrical insulation and liquid tightness realized in the previous work can be performed later. There is no danger of change due to work, and conversely, the current collection tab realized by later work
There is no fear that the connection strength of (3) will change due to the readjustment of the tightening force of the fastening member (7) thereafter.

Further, the pressing plate (51) of the pressing member (5) has a prism piece (52) integrally protruding from the surface facing the winding electrode body (2). When tightening the squeezing nut (54), a suitable tool can also be engaged with the prismatic piece (52) to prevent the squeezing member (5) from rotating together, making simple and reliable fastening work possible. It is.

Further, in the conventional cylindrical lithium secondary battery shown in FIG. 9, the current collecting tab (3) is separated from the winding electrode body (2) by a flange to weld the current collecting tab (3). The current collecting tab (3) needs to be formed to be much longer than the linear distance to the portion (92), thereby increasing the electric resistance of the current collecting tab (3). Since the welding operation is not required for lithium-ion rechargeable batteries,
(3) can be formed shorter than in the prior art, thereby making it possible to reduce the electric resistance.

[0032]

EXAMPLE Next, the results of performance comparison experiments of a prototype of a cylindrical lithium secondary battery of the present invention (FIGS. 1 to 3) and a conventional cylindrical lithium secondary battery (FIGS. 7 to 9) were performed. Will be described. Preparation of Positive Electrode LiCoO ₂ (lithium composite oxide) as a positive electrode active material and carbon as a conductive agent were mixed at a weight ratio of 90: 5 to prepare a positive electrode mixture. Next, polyvinylidene fluoride as a binder was dissolved in N-methyl-2-pyrrolidone (NMP) to prepare an NMP solution. Then, the positive electrode mixture and the NMP solution are mixed so that the weight ratio of the positive electrode mixture to polyvinylidene fluoride becomes 95: 5 to prepare a slurry, and the slurry is applied to both surfaces of an aluminum foil as a positive electrode current collector. It was applied by a doctor blade method and dried at 150 ° C. for 2 hours to produce a positive electrode.

Preparation of Negative Electrode Polyvinylidene fluoride as a binder was dissolved in NMP to prepare an NMP solution, and the weight ratio of graphite carbon powder (carbon material) having a particle diameter of 10 μm to polyvinylidene fluoride was 85:
The resulting mixture was kneaded so as to obtain a slurry and prepared as a slurry. This slurry was applied to both sides of a nickel foil as a negative electrode current collector by a doctor blade method, and vacuum dried at 150 ° C. for 2 hours to produce a negative electrode.

Preparation of Electrolyte Solution LiPF ₆ was dissolved in a solvent in which ethylene carbonate and diethyl carbonate were mixed at a volume ratio of 1: 1 at a ratio of 1 mol / l to prepare an electrolyte solution.

On the surface of the aluminum foil constituting the assembled positive electrode of the battery of the present invention , a thickness of 0.
Ten 1 mm aluminum current collecting tabs were welded at regular intervals, and a 0.1 mm thick nickel current collecting tab was formed on the surface of the nickel foil constituting the negative electrode.
Weld at regular intervals. Then, the separator is interposed between the positive electrode and the negative electrode and spirally wound to form a wound electrode body. As the separator, a microporous membrane made of ion-permeable polyethylene was used. This wound electrode body is loaded inside a cylindrical body that becomes a battery can, and positive and negative current collecting tabs extending from the wound electrode body are respectively attached to the lid of the electrode terminal mechanism of the present invention. After being sandwiched and connected between the pressure plate and the pressure receiving plate, the lid was welded and fixed to the cylinder to complete the cylindrical lithium secondary battery according to the present invention (the battery of the present invention). The battery can has a diameter of 60 mm,
The one with a height of 180 mm was used. Battery voltage is 3.6
V, the battery capacity was 30 Ah (1/8 C discharge).

Assembly of Battery of Comparative Example A wound electrode body manufactured in the same manner as the battery of the present invention was loaded into a cylindrical body, and positive and negative current collecting tabs extending from the wound electrode body were respectively covered with a lid. After being connected by spot welding to the conventional electrode terminal mechanism attached to the above, the lid was welded and fixed to the cylinder to complete a conventional cylindrical lithium secondary battery (comparative battery). The spot welding conditions were a voltage of 2 V, a maximum output current of 150 A, and a conduction time of 2 msec.

Evaluation of Battery In the battery of the present invention and the battery of the comparative example, after the current collecting tab was connected to the electrode terminal mechanism and before the lid was fixed to the cylindrical body by welding (see FIG. 6A), Approximately 500g between cylinder and lid
When a tensile load of 10 m was applied for 10 minutes and the presence or absence of a cut in the connection portion of the current collection tab with the electrode terminal mechanism was examined, the number of the prototypes cut by the current collection tab out of 50 prototypes was determined by the present invention. In the case of the battery, the value was zero, whereas in the case of the battery of the comparative example, 4
In the three prototypes, the current collecting tab was cut at the weld. From these results, it is clear that the cylindrical lithium secondary battery of the present invention provides sufficient connection strength between the current collecting tab and the electrode terminal mechanism.

When the time required for assembling the batteries of the battery of the present invention and the battery of the comparative example was measured, as shown in FIG. 5 (a), the battery of the present invention Approximately 1 to attach the fastening member (7) to (12)
It takes about one minute to store the wound electrode body (2) in the cylindrical body (11) as shown in FIG. (B), and the pressure plate (51) and the pressure receiving plate () as shown in FIG. It takes about 5 minutes to insert the current collecting tab (3) between 6)
It takes about one minute to insert the pinching member (5) through the fastening member (7) and screw the pinching nut (54) into the screw portion (53) as shown in FIG. For 12), as shown in FIG.
It takes about one minute to attach the fastening member (7) to (12).
Current collecting tab (3) between the pressure plate (51) and the pressure receiving plate (6)
It takes about 5 minutes to insert the pressing member (5) into the fastening member (7) and about 1 minute to screw the pressing nut (54) into the screw portion (53) as shown in FIG. 6 (a). Was required, and the time required until the welding process shown in FIG.

On the other hand, in the battery of the comparative example, one of the lids (12) shown in FIG.
Approximately 1 minute for mounting
Approximately 1 minute for storing (2), the flange (9) of the electrode terminal mechanism (9)
About 40 minutes to weld the plurality of current collecting tabs (3) to 2), and about 1 minute to attach the electrode terminal mechanism (9) to the lid (12) for the other lid (12). It takes about 40 minutes to weld the plurality of current collecting tabs (3) to the flange (92) of the electrode terminal mechanism (9), and the total time required until the lid (12) welding process is completed. The time was about 83 minutes. From these results, in the conventional cylindrical lithium secondary battery, the welding operation of the current collecting tab required a long time, and the battery assembling time was increased, but the cylindrical lithium secondary battery according to the present invention. According to the above, it is clear that the time required for connecting the current collection tab is significantly reduced, and as a result, the battery assembly time is also significantly reduced.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing a main part of a cylindrical lithium secondary battery according to the present invention.

FIG. 2 is a perspective view showing an appearance of the cylindrical lithium secondary battery.

FIG. 3 is an exploded perspective view of an electrode terminal mechanism employed in the cylindrical lithium secondary battery.

FIG. 4 is an exploded perspective view showing a part of the wound electrode body.

FIG. 5 is a view showing a first half of an assembling process of the cylindrical lithium secondary battery according to the present invention.

FIG. 6 is a diagram showing a latter half of the above process.

FIG. 7 is a perspective view showing the appearance of a conventional cylindrical lithium secondary battery.

FIG. 8 is an exploded perspective view of the cylindrical lithium secondary battery.

FIG. 9 is a sectional view of the cylindrical lithium secondary battery, corresponding to FIG.

[Explanation of symbols]

 (1) Battery can (11) Cylindrical body (12) Lid (2) Winding electrode body (3) Current collecting tab (4) Electrode terminal mechanism (5) Clamping member (50) Shaft (51) Clamping plate (53) Screw part (54) Pressing nut (6) Pressing receiving plate (7) Fastening member (71) Screw part (72) Flange part (73) Fastening nut

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiyuki Noma 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Koji Nishio 2-chome, Keihanhondori, Moriguchi-shi, Osaka No. 5-5 in Sanyo Electric Co., Ltd.

Claims (7)

[Claims] 1. A winding electrode body (2) is accommodated in a battery can (1) in which a lid (12) is fixed to an opening of a cylindrical body (11). ) Is a positive electrode (21) containing a lithium composite oxide, and a separator (22) impregnated with a non-aqueous electrolyte.
And a negative electrode (23) containing a carbon material are overlapped and spirally wound, and an electrode terminal mechanism (4) is attached to a lid (12) of the battery can (1). The body (2) and the electrode terminal mechanism (4) are connected to each other by a plurality of current collecting tabs (3), and the electric power generated by the winding electrode body (2) is output from the electrode terminal mechanism (4) to the outside. In the cylindrical lithium secondary battery that can be taken out, the electrode terminal mechanism (4) has a lid (1).
It is inserted into the through hole (14) opened in 2), and is fixed to the lid (12) while maintaining electrical insulation and liquid tightness with respect to the lid (12), and the lid (12) The distal end protruding outwardly has a clamping nut (54), while the proximal end protruding inside the lid (12) has a clamping pressure by screwing the clamping nut (54). It has a pressure plate (51) and a pressure receiving plate (6) to be exerted, and tips of the plurality of current collecting tabs (3) are held between the pressure plate (51) and the pressure receiving plate (6). And a cylindrical lithium secondary battery connected to the electrode terminal mechanism (4). The electrode terminal mechanism (4) is inserted into a through hole (14) formed in the lid (12), and has a screw portion (71) at a tip end protruding outside the lid (12). And a screw member (71) of the fastening member (7) having a flange portion (72) at the base end protruding inside the lid (12), and fastening. A fastening nut (73) for fixing the member (7) to the lid (12), and a through-hole (14) of the lid (12) are attached to the lid (12) and the fastening member (7). The clamping member (7) is sandwiched between the flange portion (72) of the fastening member (7) and the fastening nut (73).
An insulating packing (8) (81) for maintaining electrical insulation and liquid tightness between (12) and a shaft (5) inserted through a central hole (75) opened in the fastening member (7).
0), a screw portion (53) is formed at the tip of the shaft portion (50) protruding outside the lid (12), and the shaft portion (50) protruding inside the lid (12). A pressing member (5) to which the pressing plate (51) is fixed is provided at a base end of the pressing nut (5).
4) is screwed into the screw portion (53) of the clamping member (5),
(6) is loosely fitted to the shaft portion (50) of the pressing member (5), and the pressing plate (5) is loosely fitted.
The cylindrical lithium secondary battery according to claim 1, which is interposed between (1) and a flange portion (72) of the fastening member (7). 3. A pressing member (5) for tightening the pressing nut (54) on a pressing plate (51) of the pressing member (5) on a surface facing the winding electrode body (2). Prism pieces that should be used to prevent rotation
The cylindrical lithium secondary battery according to claim 2, wherein (52) is provided in a protruding manner. 4. Inside the battery can (1), between the opposing surfaces of the lid (12) and the insulating packing (8), the opposing surfaces of the insulating packing (8) and the flange portion (72) of the fastening member (7). Between surfaces and fastening members
The cylindrical lithium secondary battery according to claim 3, wherein O-rings (82), (83), and (84) are interposed between the flange portion (72) and the opposing surface of the pressure receiving plate (6). Next battery. 5. The clamping plate (51) and the clamping receiving plate (6) have a clamping area capable of clamping the tips of the plurality of current collecting tabs (3). The cylindrical lithium secondary battery according to claim 1. 6. The cylindrical mold according to claim 1, wherein the pressure plate (51) and the pressure receiving plate (6) are formed in a disk shape having substantially the same outer diameter as each other. Lithium secondary battery. 7. The cylindrical lithium secondary battery according to claim 1, wherein each of the current collecting tabs (3) is formed of a conductive strip-shaped foil.