JP2000285900A - Nonaqueous electrolyte battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte battery having excellent sealing properties and hardly generating wire breakage in a collector plate for connecting a terminal to an electrode. SOLUTION: This nonaqueous electrolyte battery comprises a pair of first and second electrodes having different polarities, in which an electrode active material is formed on a collector constructed of a thin sheet-like member, a container for storing these electrodes, a pair of first and second terminals 2 and 4 for connecting respective electrodes to an external circuit at every polarity, a first collector plate 5 connected to the first electrode at a position near the upper end face of the container and fixed to the first terminal 2 and a second collector plate 3 connected to the second electrode at a position near the lower end face of the container, extending in the plan direction of the electrode and bent at a position near the upper end face of the container to be fixed to the second terminal 4. In the battery, the respective electrodes 2 and 4 are fixed to the container through a hermetic seal and a round is mounted on a bent part 3d of the second collector plate 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a non-aqueous electrolyte battery such as a lithium ion secondary battery, and more particularly to a non-aqueous electrolyte battery used at high acceleration.

[0002]

2. Description of the Related Art Lithium-ion secondary batteries have high safety, high energy density and long life, and are therefore demanded for use in electric vehicles and for load leveling (load leveling of electric power).

[0003] Generally, a lithium ion secondary battery contains a pair of positive and negative electrodes, a separator and an electrolyte (usually an organic electrolyte) interposed between the electrodes, and accommodates these electrode elements, and has an end face for connecting to an external circuit. And a container provided with terminals.

In recent years, as an electrode, a type in which an electrode active material is formed on a current collector formed of a metal foil, a laminate of a metal thin film and a resin film, or the like is used for weight reduction. In order to connect such a thin electrode to a terminal, a current collector plate made of a metal plate that is easily bent is used.
The current collector plate is partially processed into a fold shape, sandwiches the electrode at the fold portion, is connected to the electrode by ultrasonic welding or caulking, and is fixed to the terminal using a rivet at a flat portion. I have. Usually, in order to prevent a short circuit, the portion of the fold to which the electrodes are connected is located near the terminal, that is, at the upper edge of the electrode in one electrode (for example, the negative electrode), and in the other electrode (for example, the positive electrode). Is on the opposite side of the terminal, ie, on the lower edge of the electrode. In this case, the current collector connected to the other electrode needs to be connected to the terminal, so it extends from the lower end of the electrode to the upper end along the electrode surface, and is bent at a right angle at the height of the rivet in order to caulk the rivet. Can be

[0005] As a method for hermetically fixing the terminal and the container, a seal ring or a gasket made of an insulating material is interposed between the terminal and an upper end surface (usually corresponding to a lid) of the container and the outer peripheral surface of the terminal is fixed. In general, a lock nut is screw-fitted to a male screw formed in the above.

[0006]

However, since the terminal is also fixed to the current collector plate, as shown in the above-mentioned example of the positive electrode,
In the case where the current collector is bent at the height of the rivet and riveted, if the bending angle is not exactly a right angle, the terminal is pushed or pulled by the current collector and receives a vertical force. As a result, the sealing performance of a sealing member such as a seal ring or a gasket is deteriorated.

However, a groove having a V-shaped cross section is provided along the fold line on the valley fold side of the bent portion of the current collector plate, and the V-shaped groove is closed at the time of bending so that the current collector plate can be bent at a right angle. However, if a large acceleration is applied, the V-shaped groove easily breaks the wire. If only used as a power source for electric vehicles as before,
It would have been good if it had impact resistance of about 10G, but it is clear that if the impact resistance requirement becomes more severe in the future, the tendency of disconnection in the V-shaped groove will be remarkable. Therefore, an object of the present invention is to provide a non-aqueous electrolyte battery which is excellent in sealing properties and in which a current collector plate connecting a terminal and an electrode is hardly disconnected.

[0008]

In order to achieve the above-mentioned object, a non-aqueous electrolyte battery according to the first aspect of the present invention is a non-aqueous electrolyte battery in which electrode active materials are formed on a current collector composed of a thin planar member and have different polarities. First and second pair of electrodes, a container for accommodating the electrodes, and first and second pair of terminals fixed to the upper end surface of the container and connecting each electrode to an external circuit for each polarity. The first current collector plate connected to the first electrode and the position near the upper end surface of the container and fixed to the first terminal, and connected to the second electrode and the position near the lower end surface of the container, In a non-aqueous electrolyte battery comprising a second current collector plate that extends along the surface direction of the electrode and is bent at a position close to the upper end surface of the container and fixed to the second terminal, each terminal is connected via a hermetic seal. The second current collector plate is fixed to a container and has a corner of a bent portion. Wherein the radius R is attached.

According to the non-aqueous electrolyte battery of the first invention,
Since each terminal is fixed to the container via the hermetic seal, the sealing property of the terminal fixing portion is ensured even if the current collecting plate does not form a right-angled bent angle. Rather, by adding a radius R to the corner of the bent portion of the current collector plate, the stress applied to the bent portion at the time of vibration is dispersed, and cutting becomes difficult. As a result, impact resistance is improved.

[0010] The non-aqueous electrolyte battery according to the second aspect of the present invention that achieves the above object has a first and second pair of electrodes having different polarities, each formed by forming an electrode active material on a current collector formed of a thin planar member. A container for accommodating the electrodes, a first and second pair of terminals fixed to the upper end surface of the container for connecting each electrode to an external circuit for each polarity, and a first electrode and a container. The first current collector plate connected at a position close to the end face and fixed to the first terminal, and connected at a position near the lower end face of the second electrode and the container, and extends along the surface direction of the electrode, In a non-aqueous electrolyte battery comprising a second current collector plate that is bent at a position near the upper end surface of the container and fixed to the second terminal,
A bag made of an electrolytic solution-resistant rubber is installed in a space sandwiched between the portion of the second current collector plate fixed to the second terminal and the edge of the electrode, and the bag is filled with an insulating resin. It is characterized by.

According to the non-aqueous electrolyte battery of the second invention,
A bag made of an electrolytic solution-resistant rubber is installed in a space between the fixed portion of the second current collector plate and the second terminal, and a space between the edges of the electrodes,
Since the bag is filled with the insulating resin, the insulating resin functions as a spacer without being eroded by the electrolytic solution. Therefore, the fixed portion of the second current collector plate with the second terminal is supported by the electrode via the spacer, so that even if the battery is impacted, an excessive load is not applied to the bent portion of the second current collector plate. In addition, disconnection of the second current collector plate is prevented. In addition, since the electrode current collector is formed of a planar member, the space between the edge of the electrode and the portion of the second current collector that is fixed to the second terminal does not have a constant volume and does not have a fixed shape. Is made of rubber, the space can be filled with an appropriate amount of resin. The resin is preferably a liquid that can be injected with a syringe needle or the like at the time of filling and solidifies after filling.

The non-aqueous electrolyte battery according to the third aspect of the present invention, which achieves the above object, comprises a first and a second pair of electrodes having different polarities, each having an electrode active material formed on a current collector formed of a thin planar member. A container for accommodating the electrodes, a first and second pair of terminals fixed to the upper end surface of the container for connecting each electrode to an external circuit for each polarity, and a first electrode and a container. The first current collector plate connected at a position close to the end face and fixed to the first terminal, and connected at a position near the lower end face of the second electrode and the container, and extends along the surface direction of the electrode, In a non-aqueous electrolyte battery comprising a second current collector plate that is bent at a position near the upper end surface of the container and fixed to the second terminal,
A spacer made of an insulating solid is interposed between a portion of the second current collector plate fixed to the second terminal and an upper end surface of the container.

According to the nonaqueous electrolyte battery of the third invention,
Since the spacer is interposed between the fixed portion of the second current collector plate with the terminal and the upper end surface of the container, the fixed portion of the second current collector plate with the terminal is sharply upward due to an impact. Even if a force acts, it is held down by the upper end surface of the container via the spacer. For this reason, even if the battery receives an impact, an excessive load is not applied to the bent portion of the second current collector, and disconnection of the second current collector is prevented.

The non-aqueous electrolyte battery according to the fourth aspect of the present invention, which achieves the above object, has a first and second pair of electrodes having different polarities, each having a current collector formed of a thin planar member and having an electrode active material formed thereon. A container for accommodating the electrodes, a first and second pair of terminals fixed to the upper end surface of the container for connecting each electrode to an external circuit for each polarity, and a first electrode and a container. The first current collector plate connected at a position close to the end face and fixed to the first terminal, and connected at a position near the lower end face of the second electrode and the container, and extends along the surface direction of the electrode, In a non-aqueous electrolyte battery comprising a second current collector plate that is bent at a position near the upper end surface of the container and fixed to the second terminal,
A spacer made of an insulating solid is interposed between the second current collector plate and the lower end surface of the container.

According to the nonaqueous electrolyte battery of the fourth invention,
Since the spacer is interposed between the second current collecting plate and the lower end surface of the container, the second current collecting plate can be positioned below the container via the spacer even if a sudden downward force acts due to an impact. Supported by end faces. For this reason, even if the battery receives an impact, an excessive load is not applied to the bent portion of the second current collector, and disconnection of the second current collector is prevented.

[0016]

Embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the negative electrode, the negative electrode terminal, and the negative electrode current collector plate respectively correspond to the first electrode, the first terminal, and the first current collector plate in the present invention, and the positive electrode, the positive electrode terminal, and the positive electrode current collector plate each correspond to the second electrode. It corresponds to an electrode, a second terminal, and a second current collector.

Embodiment 1 FIG. 1 is a perspective view showing an electrode element used in a lithium ion secondary battery of a first embodiment. The electrode element 1 includes a positive electrode 1a in which an electrode active material is formed on a current collector made of a thin planar member such as a metal foil or a metal / resin laminated sheet.
And negative electrode 1b and separator 1c interposed between these electrodes
Consists of The metal used for the current collector of the positive electrode 1a is usually aluminum, and the active material is a lithium-cobalt composite oxide. The metal used for the current collector of the negative electrode 1b is usually copper or nickel, and the active material is graphite. A polyethylene porous membrane is used for the separator 1c. The positive electrode 1a, the separator 1c, and the negative electrode 1b are sequentially superimposed and wound in an oval spiral shape as shown in FIG. 1 with the positive electrode 1a inside, and a predetermined portion of the current collector plate at the upper or lower edge in the winding axis direction. Connected to In this embodiment, the negative electrode is the upper edge,
Since the positive electrode is connected to the current collector at the lower edge, the upper edge of the negative electrode current collector protrudes slightly above the separator, and conversely, the lower edge of the positive electrode current collector is slightly lower than the separator. Protruding.

FIG. 2 is a perspective view showing a current collector connected to the electrode element 1 and terminals for connecting each electrode to an external circuit for each polarity. Each of the terminals 2 and 4 has a cylindrical shape with a screw formed on the inner periphery. The positive terminal 2 and the negative terminal 4 are fixed to the positive current collector 3 and the negative current collector 5 by rivets. The positive electrode current collector plate 3 includes a fold portion 3a for sandwiching the positive electrode current collector at a position facing the lower edge of the electrode element 1, a lead portion 3b orthogonal to the fold portion 3a and extending in the electrode surface direction, and a positive electrode. A metal plate is punched or cut and molded into a predetermined shape having a fold portion 3a, and then the fold portion 3a, a lead portion 3b, and a lead portion 3b are formed.
And the fixing portion 3c is bent at a right angle. However, a corner 3d of a bent portion between the lead portion 3b and the fixing portion 3c is provided with a radius R inside and outside as shown in a sectional view in FIG. The size of R is
0.8 to 3.2 mm, thickness of current collector plate 0.5 to 2 m
m is about 1.6 times.

On the other hand, the negative electrode current collector 5 is
A positive electrode current collector plate comprising a fold portion 5a for sandwiching the negative electrode current collector at a position facing the upper end edge of the negative electrode terminal and a fixing portion 5c for fixing to the negative electrode terminal 4, except that there is no need for bending since there is no lead portion. 3 is formed in the same manner.

Each of the terminals 2 and 4 is surrounded by a metal ring 6 for fixing to a lid of a container to be described later, and both terminals are insulated to hermetically seal the metal ring 6 and the terminals 2 and 4 and to hermetically seal them. A ceramic or glass ring 7 is fitted between them and hermetically sealed with a metal brazing.

The electrodes 1a and 1b of the electrode element 1 are
As shown in FIG. 4 as a perspective view, the upper end edge or the lower end edge thereof is connected to and fixed to the current collector plate by being crimped between the corresponding fold portions of the current collector plates 3 and 5. For convenience of illustration, the positive electrode current collector 3 and the positive electrode terminal 2 are omitted. FIG. 5 is a perspective view showing an assembly of the electrode element 1, the current collectors 3, 5, and the terminals 2, 4. FIG.
FIG. 5 is a sectional view taken along line XX of FIG.

The above assembly is housed in a container 8 as shown in an exploded perspective view in FIG. 7, and is closed by a lid 10 in which a liquid injection hole 9 is formed. The lid 10 and the container 8 are fixed by welding. A hermetic seal composed of rings 6, 7 and a metal braze 11 is interposed between the terminals 2, 4 and the lid 10, as shown in a sectional view in FIG. ing. After sealing, for example, LiPF
_An electrolyte composed of a mixed solution of ethylene carbonate: methyl ethyl carbonate = 4: 6 (volume ratio) containing 1 mol / L of ₆ is injected from the injection hole 9, closed, charged, and charged to complete the battery.

In the battery of this embodiment, since the terminals 2 and 4 and the lid 10 of the container are fixed via the hermetic seal, the sealing reliability is high. Moreover, since the corner of the bent portion of the positive electrode current collector plate 3 is provided with a radius 3d,
The stress applied to the bent part during vibration is dispersed, making it difficult to cut. As a result, the impact resistance is excellent.

Embodiment 2 FIGS. 9 and 1 show a lithium ion secondary battery according to a second embodiment.
It will be described together with 0. FIG. 9 is a perspective view showing an assembly of a current collector and a terminal used in the battery of the second embodiment, and FIG. 10 is a sectional view showing a bent portion of a positive electrode current collector of the assembly.

The same components as those in the first embodiment are denoted by the same reference numerals. In this embodiment, the corners 3d of the bent portion of the positive electrode current collector plate 3 are not provided with the radius R, but are provided with a V-shaped groove having a 45-degree slope on the valley fold side. It is precisely bent at right angles by bending. Further, a bag 12 made of an electrolytic solution rubber, for example, EPDM is installed in a space sandwiched between the fixed portion 3 c of the positive electrode current collector plate 3 and the positive electrode terminal 2 and the upper edge of the electrode element 1. Is filled with an insulating resin (not shown), for example, a polyolefin polyol adhesive. Other configurations are the same as those of the first embodiment.

According to the battery of this embodiment, the bag 12 made of the electrolyte-resistant rubber is installed in the space sandwiched between the fixing portion 3c and the upper edge of the electrode element 1.
Since the insulating resin 2 is filled with the insulating resin, the insulating resin functions as a spacer without being eroded by the electrolytic solution. Therefore, the fixing portion 3c is supported by the electrode element 1 via the spacer, and even if the battery receives an impact, an excessive load is not applied to the bent portion 3d of the positive electrode current collector plate 3, and the positive electrode current collector Disconnection of the plate 3 is prevented.
Further, since the electrode current collector is made of a sheet-like member, the space in which the bag 12 is installed has a fixed volume and a fixed shape.
Since 2 is made of rubber, the space can be filled with an appropriate amount of resin.

Embodiment 3 A lithium ion secondary battery according to Embodiment 3 will be described with reference to FIG. FIG. 11 shows an assembly of an electrode element, a current collector, and a terminal used in the battery according to the third embodiment as indicated by XX in FIG.
It is sectional drawing cut | disconnected along the line equivalent to a line.

The same components as those in the first embodiment are denoted by the same reference numerals. Also in this embodiment, the corner 3d of the bent portion of the positive electrode current collector plate 3 is not provided with a radius R, and a V-shaped groove having a 45-degree slope on the valley fold side is provided. It is precisely bent at right angles by bending. Further, between the fixed portion 3c of the positive electrode current collector plate 3 and the positive electrode terminal and the upper end surface of the container 8, that is, the lid 10,
In addition, spacers 13 and 14 made of polypropylene are interposed between the positive electrode current collector plate 3 and the lower end surface, that is, the bottom of the container 10. Other configurations are the same as those of the first embodiment.

According to the battery of this embodiment, since the spacers 13 and 14 are interposed in the upper and lower spaces between the positive electrode current collector 3 and the container 8, respectively, the positive electrode current collector 3 Even if a force is applied, the lid 10 is
And supported by the bottom of the container 8. For this reason, even if an impact is applied to the battery, an excessive load is not applied to the bent portion 3d of the positive electrode current collector plate 3, and disconnection of the positive electrode current collector plate 3 is prevented.

[0030]

EXAMPLES-Example 1-In the battery of the first embodiment, the positive electrode current collector plate 3 was made of aluminum, a thickness of 1 mm, and a bent portion 3d.
A vibration test was performed under the following conditions using a sample having a width of 50 mm and a radius R of 1.6 mm. For comparison, a vibration test was similarly performed on a valley-folded side having a V-shaped groove with a depth of 0.3 mm and bending at a right angle instead of attaching a radius R to the bent portion 3d.

Vibration direction: up and down Frequency: sine waveform 30 to 70 Hz Acceleration: 12 G, 20 G, 25 G, 30 G, 35 G Sweep speed: 1 minute reciprocation Number of applications: 1 reciprocation The battery withstood up to 25G, but the battery with a V-shaped groove
, The bent portion 3d was cut.

Example 2 In the battery of the second embodiment, the positive electrode current collector plate 3 was made of aluminum, a thickness of 1 mm, and a bent portion 3d.
Of 50 mm wide and 0.3 mm deep V-shaped groove,
A vibration test was performed in the same manner as in Example 1 using EDPM as the bag 12 and Polytail HA manufactured by Mitsubishi Chemical Corporation as the resin to be filled therein. As a result, the positive current collector 3
Endured up to 5G.

Example 3 In the battery of the third embodiment, the positive electrode current collector plate 3 was made of aluminum, a thickness of 1 mm, and a bent portion 3d.
Of 50 mm wide and 0.3 mm deep V-shaped groove,
A vibration test was performed in the same manner as in Example 1 using polypropylene as the spacers 13 and 14. As a result, the positive electrode current collector plate 3 withstood up to 20G.

[0034]

As described above, the nonaqueous electrolyte battery of the present invention has excellent resistance to shock and vibration, and is therefore useful for power sources for automobiles and satellites.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an electrode element used for a lithium ion secondary battery of a first embodiment.

FIG. 2 is a perspective view showing a current collector plate and terminals used in the lithium ion secondary battery of the first embodiment.

FIG. 3 is a partial cross-sectional view of a positive electrode current collector used in the lithium ion secondary battery of the first embodiment.

FIG. 4 is a perspective view showing a connection structure between an electrode element and a current collector used in the lithium ion secondary battery of the first embodiment.

FIG. 5 is a perspective view showing an assembly of an electrode element, a current collector, and a terminal used in the lithium ion secondary battery of the first embodiment.

FIG. 6 is a sectional view taken along the line XX of FIG. 5;

FIG. 7 is an exploded perspective view of the lithium ion secondary battery of the first embodiment.

FIG. 8 is a cross-sectional view showing a portion where the terminal of the lithium ion secondary battery of the first embodiment is fixed to the lid of the container.

FIG. 9 is a perspective view showing an assembly of a current collector and terminals used in the battery of the second embodiment.

FIG. 10 is a sectional view showing a bent portion of a positive electrode current collector plate of the assembly of FIG. 9;

11 is a cross-sectional view of an assembly of an electrode element, a current collector, and a terminal used in the battery according to the third embodiment, taken along a line corresponding to line XX in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrode element 2 positive electrode terminal 3 positive electrode current collector plate 4 negative electrode terminal 5 negative electrode current collector plate 6 metal ring 7 ring 8 container 9 liquid injection port 10 lid 11 metal brazing 12 bags 13, 14 spacer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H011 AA01 FF04 GG01 HH08 HH09 5H022 AA09 BB02 CC03 CC12 CC22 KK03 5H029 AJ11 AK00 AL00 AM03 AM05 AM07 BJ02 BJ14 DJ01 DJ03 DJ05 EJ11

Claims (4)

[Claims] 1. A pair of first and second electrodes having different polarities, each having an electrode active material formed on a current collector formed of a thin planar member, a container for accommodating the electrodes, and an upper end surface of the container. First and second pair of terminals that are fixed and connect each electrode to an external circuit for each polarity, and are connected to the first electrode and a position near the upper end surface of the container and are fixed to the first terminal. And a second current collector connected to the second electrode at a position near the lower end surface of the container, extending along the surface direction of the electrode, and bent at a position near the upper end surface of the container. A non-aqueous electrolyte battery comprising a second current collector plate fixed to the container, wherein each of the terminals is fixed to the container via a hermetic seal, and a radius R is attached to a corner of a bent portion of the second current collector plate. Non-aqueous electrolyte battery characterized by being used. 2. A pair of first and second electrodes having different polarities, each having an electrode active material formed on a current collector formed of a thin planar member, a container for accommodating the electrodes, and an upper end surface of the container. First and second pair of terminals that are fixed and connect each electrode to an external circuit for each polarity, and are connected to the first electrode and a position near the upper end surface of the container and are fixed to the first terminal. A first current collector plate, which is connected to the second electrode at a position near the lower end surface of the container, extends along the surface direction of the electrode, and is bent at a position near the upper end surface of the container to form a second terminal A non-aqueous electrolyte battery comprising: a second current collector plate fixed to the non-aqueous electrolyte battery; a portion fixed to the second terminal of the second current collector plate; Non-aqueous electrolysis characterized in that a bag is installed and the bag is filled with an insulating resin. Battery. 3. A pair of first and second electrodes having different polarities, each having an electrode active material formed on a current collector formed of a thin planar member, a container for accommodating the electrodes, and an upper end surface of the container. First and second pair of terminals that are fixed and connect each electrode to an external circuit for each polarity, and are connected to the first electrode and a position near the upper end surface of the container and are fixed to the first terminal. And a second current collector connected to the second electrode at a position near the lower end surface of the container, extending along the surface direction of the electrode, and bent at a position near the upper end surface of the container. A non-aqueous electrolyte battery comprising a second current collector plate fixed to the non-aqueous electrolyte battery, wherein a spacer made of an insulating solid is provided between a portion of the second current collector plate fixed to the second terminal and an upper end surface of the container. Non-aqueous electrolyte battery characterized by being interposed. 4. A pair of first and second electrodes having different polarities, each having an electrode active material formed on a current collector formed of a thin planar member, a container for accommodating the electrodes, and an upper end surface of the container. First and second pair of terminals that are fixed and connect each electrode to an external circuit for each polarity, and are connected to the first electrode and a position near the upper end surface of the container and are fixed to the first terminal. And a second current collector connected to the second electrode at a position near the lower end surface of the container, extending along the surface direction of the electrode, and bent at a position near the upper end surface of the container. A non-aqueous electrolyte battery having a second current collector plate fixed to the non-aqueous electrolyte, wherein a spacer made of an insulating solid is interposed between the second current collector plate and the lower end surface of the container. Non-aqueous electrolyte battery.