JPH10223253A - Stacked battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stacked battery in which damage of a separator part is suppressed, contact of a current collector is increased, and internal resistance is decreased. SOLUTION: A stacked battery uses a current collector-separator member 1, having a sheet-shaped separator part 2 and current collectors 31, 32. An adjacent positive electrode and a negative electrode are separated with the separator part 2 of the current collector-separator member 1, and a plurality of these electrodes are stacked. Contact of the current collectors 31, 31 in the stacking direction is made larger than the contact of the separators 2 in the stacking direction. Wedged inclined surfaces 3c, 3d may be formed in the current collectors 31, 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stacked battery having a structure in which a plurality of positive and negative electrode bodies and a plurality of separators for partitioning the same are stacked.

[0002]

2. Description of the Related Art As a stacked battery, a storage battery having a structure shown in FIGS. 7 and 8 has been disclosed (Japanese Utility Model Laid-Open No. 4-47266). In this storage battery, as can be understood from FIGS. 7 and 8, an electrode group 400 having a laminated structure in which a sheet-shaped separator portion 300 is interposed between the adjacent positive electrode plate 100 and negative electrode plate 200 is used. Electrode group 400 is placed in battery case 50
0 in the storage room 503. 8, the wedge-shaped spacer plate 700 is press-fitted between the side wall 501 of the battery case 500 and the electrode plate group 400 as can be understood from FIG.

[0003] In the case 500, generally, the inner surface of the side wall 501 of the case 500 is formed with a draft at the time of molding.
In the upper part 501a, the degree of pressurization in the laminating direction tends to be lower than in the lower part 501c. Therefore, the separator part 3
The density of the upper half of 00 tends to be lower than the density of the lower half, and there is a problem that the retention of the electrolyte in the upper half of the separator 300 is apt to decrease.

The above-described technique shown in FIGS. 7 to 9 focuses on this inconvenience and press-fits a wedge-shaped spacer plate 700 to form an upper portion 50 of the side wall 501 of the battery case 500.
The pressure degree in 1a is increased. Similarly, Japanese Utility Model Application Laid-Open No. 59-9473 discloses a structure in which a wedge-shaped spacer plate is press-fitted between a side wall surface of a battery case and the plate group when the electrode group is housed in the battery case. A stacked battery is disclosed. According to the stacked battery according to this publication, since the positive electrode plate and the negative electrode plate constituting the electrode group are compressed in the thickness direction, the active material of the positive electrode plate and the negative electrode plate can be prevented from falling off. It is considered to be advantageous for extending the life.

[0005]

In the technique shown in FIGS. 7 to 9 (Japanese Utility Model Laid-Open No. 4-47266), as can be understood from FIG. 9, a wedge-shaped inclined surface 701 is formed on the spacer plate 700. Have been. Wedge-shaped inclined surface 70
1 is formed over the entire length of the electrode plate group 400 in the width direction, that is, the arrow X direction.

Accordingly, in the electrode plate group 400, a pressing force is applied over the entire length in the width direction, that is, the arrow X direction. Therefore, the positive electrode plate 100, the negative electrode plate 200, and the separator portion 300 constituting the electrode plate group 400 are strongly pressed in the thickness direction over their entire widths, and as a result, their adhesion is enhanced. By the way, in recent years, improvement of battery output per battery volume has been particularly demanded. In the above-mentioned publication technology, the press-fitted spacer plate 700 does not contribute to the original battery reaction or current collection function.

As described above, the wedge-shaped spacer plate 700 is used.
Although it does not contribute to the original battery reaction or current collecting function, it is mounted on the battery, so that extra dead space is required and the battery output per volume of the battery is easily reduced. Further, in the stacked battery according to the publication technology shown in FIGS. 7 to 9 described above, the positive electrode plate 100 and the negative electrode plate 20
0 and the separator portion 300 are strongly pressed in the stacking direction, that is, in the thickness direction thereof, so that the positive electrode plate 100 and the negative electrode
When 0 has a corner portion, the corner portion separates the separator portion 30.
0 may be damaged.

When the stacked battery is a nickel-hydrogen battery, a hydrogen storage alloy is easily used as an active material. However, since the powder of the hydrogen storage alloy tends to have corners, a high degree of pressurization is required. However, there is a possibility that the separator section 300 may be damaged. The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a stacked battery that is advantageous in reducing the internal resistance of a battery by increasing the contact property of a current collector while suppressing damage to a separator portion.

[0009]

According to a first aspect of the present invention, there is provided a stacked battery comprising a sheet-shaped or plate-shaped separator and a current collector provided at an end of the separator in the width direction. Using a separator member, a stacked type having a structure in which a plurality of separators / collector members, a positive electrode body, and a plurality of negative electrode bodies are respectively stacked so that the adjacent positive electrode body and negative electrode body are separated by a separator portion of the current collector separator member. In the battery-collecting and current-collecting separator member, the contact degree in the stacking direction of the current collector is set to be larger than the contact degree in the stacking direction of the separator portion.

According to a second aspect of the present invention, in the first aspect, the current collector / separator member includes a positive electrode current collector provided on one side of the separator portion in the width direction and a positive electrode current collector provided on one side in the width direction of the separator portion. And a negative electrode current collector provided on the other side, at least one of the positive electrode current collector and the negative electrode current collector has a wedge-shaped inclined surface that increases the degree of contact in the stacking direction of the current collector. It is characterized by having.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the laminated battery according to the present invention, in the current collector / separator member, the degree of contact of the current collector in the direction of lamination is set to be higher than the degree of contact of the separator in the direction of lamination. In this case, a method in which a wedge-shaped inclined surface is provided on the current collector and pressure is applied in the stacking direction of the current collector by using a component force by the wedge-shaped inclined surface can be adopted.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. This embodiment is a case where the present invention is applied to a nickel-hydrogen secondary battery. (Configuration of Embodiment) As can be understood from FIGS. 1 and 2,
The current-collecting / separating member 1 includes a sheet-shaped or plate-shaped separator portion 2 and a current collector 3 provided at the end of the separator portion 2 in the width direction, that is, in the arrow XA direction. The current collector 3 has a current collecting function, and is made of a conductive material such as a nickel-based or copper-based material.

The current collector 3 includes a positive electrode current collector 31 provided on one side in the width direction of the separator portion 2, that is, on one side in the direction of the arrow XA.
The negative electrode current collector 32 is provided on the other side of the separator portion 2 in the width direction, that is, on the other side in the arrow XA direction. FIG.
As shown in the figure, the positive electrode current collector 31 is formed with wedge-shaped inclined surfaces 3c and 3d facing each other. The positive electrode current collector 31 includes two first divided bodies 31x and 31y divided in the thickness direction. As can be understood from FIG. 3, the first divided body 31x has the inclined surface 3c,
The division body 31y has the inclined surface 3d.

The first divided bodies 31x and 31y are connected by fasteners 3k such as screws, and sandwich the separator 2 in the thickness direction. Similarly, as can be understood from FIG. 1, the negative electrode current collector 32 has wedge-shaped inclined surfaces 3c and 3d.
Are formed to face each other. Negative electrode current collector 3
2 is two second divided bodies 32x, 3 divided in the thickness direction
2y. As can be understood from FIG. 1, the second divided body 32x has the inclined surface 3c, and the second divided body 32y
Has an inclined surface 3d. The second divided bodies 32x and 32y are connected by a fastener 3k, and sandwich the separator 2 in the thickness direction.

The separator section 2 has a function of separating a positive electrode plate 5 as a positive electrode body and a negative electrode plate 6 as a negative electrode body, as described later. In this embodiment, the separator 2 is an organic type (for example, a polypropylene type or a polyamide type).
Of fiber aggregates. 4 and 5 show the principle of assembling the stacked battery according to the present embodiment. When assembling the stacked battery, as can be understood from FIGS. 4 and 5, a plurality of adjacently-collecting / separating separator members 1 are arranged upside down in a stacked state. In this state, a pressing operation is performed in the height direction, that is, in the direction of the arrow WP. Thereby, the current collector / separator member 1 is placed in the storage chamber 8 of the battery case 8.
0 is stored. As can be understood from FIG. 4, end-side current collectors 39 are provided at both ends in the stacking direction.
The end-side current collector 39 has a wedge-shaped inclined surface 39a and a vertical surface 39b.

FIG. 6 schematically shows a cross section taken along the line VI-VI of FIG. As described above, the current collecting / separating member 1
6 is stored in the storage chamber 80 of the battery case 8 in FIG.
As can be understood from FIG. 3, the current collector / separator member 1, the positive electrode plate 5, and the negative electrode plate 6 are each laminated in plural. As can be understood from FIG. 6, the adjacent positive electrode plate 5 and negative electrode plate 6 are separated by the separator portion 2 of the current collector / separator member 1 to prevent short circuit.

In the present embodiment, the negative electrode plate 6 is formed by pressing a powder of a hydrogen storage alloy that functions as a negative electrode active material and storing hydrogen into a foam metal (for example, foam nickel) and then press-molding it into a sheet. is there. The positive electrode plate 5 is obtained by loading a foamed metal (for example, nickel foam) with a powder mainly composed of nickel hydroxide as a positive electrode active material into a foamed metal (for example, nickel foam), and then press-molding it into a sheet. .

As can be understood from FIG. 6, the negative electrode plate 6 has a brim-shaped electricity extraction portion 6m. The electric extraction section 6m is sandwiched between the negative electrode current collectors 32 adjacent in the stacking direction. Further, the positive electrode plate 5 has a brim-shaped electricity extraction portion 5m. The electric outlet 5m is sandwiched between the positive electrode current collectors 31 that are adjacent in the stacking direction. In the above state, the current collector / separator member 1, the positive electrode plate 5, and the negative electrode plate 6 are stored in the storage chamber 80 of the battery case 8 in a stacked state. The storage chamber 80 stores an electrolyte.

In this embodiment, as can be understood from FIG. 1, in the negative electrode current collector 32, the center line of the separator portion 2 is Pc, the protrusion amount of the second divided body 32x with respect to the center line Pc is H1, Second divided body 32y with respect to line Pc
Is set as H1 = H2 + H3, assuming that the protrusion amount of H2 is H2 and the thickness of the electricity extraction portion 6m of the negative electrode plate 6 is H3. The thickness of the electricity extraction portion 6m of the negative electrode plate 6 is taken into consideration.

The same configuration is also applied to the positive electrode current collector 31. (Effects of Embodiment) As described above, in this embodiment, the wedge-shaped inclined surfaces 3c and 3d are formed on the positive electrode current collector 31, and the wedge-shaped inclined surfaces 3c and 3d are also formed on the negative electrode current collector 32. Is formed. For this reason, the current collector separator member 1
The when accommodated in the container casing 8 with the positive electrode plate 5 and negative electrode plate 6, as can be understood from FIG. 5, acts in the stacking direction, that arrow YB direction component force F _a directed outward as突張Ri force I do.

[0021] In other words, in the thickness direction of the current collector 3, a component force F _a is applied toward the outside. Therefore, the degree of contact in the positive electrode current collector 31 increases, and the contact resistance at the boundary between the adjacent positive electrode current collectors 31 decreases. Similarly, the degree of contact in the negative electrode current collector 32 increases, and the contact resistance at the boundary between the adjacent negative electrode current collectors 32 decreases. Therefore, it can contribute to the reduction of the internal resistance of the battery.

[0022] Additionally in this embodiment, the electric extraction portion 6m of the negative electrode plate 6, for the electric extraction portion 5m of the positive electrode plate 5, strongly fixed using wedge-shaped inclined surface 3c, the component force F _a by 3d Therefore, it is possible to further contribute to the reduction of the internal resistance of the battery. Further, in the present embodiment in which the wedge-shaped inclined surfaces 3c and 3d are formed on the current collector 3, the wedge-shaped inclined surfaces 3c and 3d are provided.
Component force F _a by, although greatly acting on the current collector 3, or the separator portion 2 is not much effect, or is a working hard structure. For this reason, in the present embodiment, it is possible to prevent excessively high pressure in the thickness direction of the separator portion 2, and unlike the above-described prior art, the separator portion 2
This is advantageous in suppressing damage to the device. Therefore, as an active material,
Even when a powder having corners such as hydrogen storage alloy powder is used, it is advantageous in suppressing damage to the separator 2.

In this embodiment, the wedge-shaped inclined surface 3 is used.
c and 3d are formed on the current collector 3 having a current collecting function. Therefore, unlike the related art shown in FIGS. 7 to 9 in which a wedge-shaped inclined surface is formed on the spacer plate 700 that does not contribute to the current collecting function and the battery reaction, the present embodiment is advantageous in reducing dead space, This is advantageous for securing the battery output.

(Other Examples) In the above example, the present invention is applied to a nickel-metal hydride battery. However, it is needless to say that the present invention is not limited to this and can be applied to other stacked batteries such as a lead battery and a lithium ion battery.

[0025]

According to the stacked battery of the first aspect, in the current collector / separator member, the contact of the current collector in the stacking direction is set to be larger than the contact of the separator in the stacking direction. Therefore, the degree of contact on the current collector increases,
The contact resistance at the boundary of the current collector is reduced. Therefore, it can contribute to the reduction of the internal resistance of the battery.

Furthermore, since the degree of contact in the stacking direction of the current collector is larger than the degree of contact in the stacking direction of the separator, excessive stress in the thickness direction of the separator, that is, in the stacking direction, can be prevented, and damage to the separator can be suppressed. Is advantageous. Therefore, even when powder having corners (for example, powder of a hydrogen storage alloy) is used as the active material, it is advantageous in suppressing damage to the separator.

Further, according to the stacked battery of the second aspect,
At least one of the positive electrode current collector and the negative electrode current collector has a wedge-shaped inclined surface that increases the degree of contact in the stacking direction of the current collector, so that the current collector separator member is stored in the battery case. , Due to the wedge-shaped inclined surface, a component force acts outward in the thickness direction of the current collector, thereby increasing the degree of contact with the current collector and reducing the contact resistance at the boundary of the current collector. Therefore, it can contribute to the reduction of the internal resistance of the battery.

[Brief description of the drawings]

FIG. 1 is a plan view of a current collecting / separating member.

FIG. 2 is a front view of a current collecting / separating member.

FIG. 3 is an arrow view along a line III-III in FIG. 1;

FIG. 4 is a principle view schematically showing a state in which a current collecting / separating member is housed in a housing chamber of a battery case.

FIG. 5 is a principle view schematically showing a state in which the current collecting / separating member is housed in a housing room of a battery case.

FIG. 6 is a view schematically showing a state in which the current-collecting / separating member is housed in the housing chamber of the battery case, and is a view taken along the line VI-VI in FIG.

FIG. 7 is a front view, partially in section, showing a state in which an electrode group is housed in a housing chamber of a battery case according to the prior art.

FIG. 8 relates to the prior art, and IIX-IIX in FIG.
It is sectional drawing which follows a line.

FIG. 9 is a perspective view of a wedge-shaped spacer plate according to the related art.

[Explanation of symbols]

In the drawing, reference numeral 1 denotes a current collector separator member, 2 denotes a separator portion, 3 denotes a current collector, 31 denotes a positive electrode current collector, 32 denotes a negative electrode current collector, 3c and 3d wedge-shaped inclined surfaces, and 5 denotes a positive electrode plate ( A positive electrode body), 6 is a negative electrode plate (negative electrode body), 8 is a battery case, and 80 is a storage chamber.

Claims (2)

[Claims] An anode and a cathode are disposed adjacent to each other using a current collector / separator member having a sheet-shaped or plate-shaped separator and a current collector provided at an end of the separator in the width direction. A stacked battery having a structure in which a plurality of the current collecting separator member, the positive electrode body, and the negative electrode body are stacked, such that the current collecting separator member is separated by the separator portion of the current collecting separator member. In the dual-purpose separator member, the contact degree of the current collector in the stacking direction is set to be larger than the contact degree of the separator portion in the stacking direction. 2. The positive electrode current collector according to claim 1, wherein the current collector / separator member is provided on one side in the width direction of the separator portion and on another side in the width direction of the separator portion. A negative electrode current collector, wherein at least one of the positive electrode current collector and the negative electrode current collector has a wedge-shaped inclined surface that increases the degree of contact in the stacking direction of the current collector. And a stacked type battery.