JP2000251950A - Sealed secondary battery system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealed secondary battery system capable of effectively cooling each cell in an inexpensive structure. SOLUTION: This sealed secondary battery system 1 is made up of a series connected plurality of cells 2 each formed by housing a power generating element in a battery jar 14 of a bottomed rectangular-cylindrical shape and sealing up an opening thereof. Cooling medium passages 21 are disposed on both sides of each cell 2 in the direction of its layout while cooling medium passages 18 causing the both-side cooling medium passages 21 to communicate with each other are formed between the battery jars 14 of the cells 2, and all of the side surfaces of the cells 2 including gaps between the cells 2 are forcedly cooled by a cooling medium passing through the both-side cooling medium passages 21 and the cooling medium passages 18 between the cells.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated sealed secondary battery in which a plurality of cells are arranged in series to form an integrated battery case.

[0002]

2. Description of the Related Art As a collective type sealed secondary battery of this kind,
The one disclosed in Japanese Patent Application Laid-Open No. 7-85847 is known. As shown in FIG. 11, the assembled sealed secondary battery 61 accommodates a power generating element in a battery case 63 formed in a rectangular tube shape with a bottom, and seals an opening of the battery case 63 with a lid 64. A plurality of unit cells 62 are arranged in series, and the battery case 63 of the unit cells 62 is tightly connected by an end plate 65 and a restraining band 66. Also, a positive terminal 67 and a negative terminal 68 of each unit 62 are provided. Are made to penetrate through the lid 64 and protrude upward, and these terminals 67 and 68 are sequentially connected in series by an electric connection bar 69.

Japanese Unexamined Patent Publication (Kokai) No. 6-215804 discloses a monoblock storage battery in which a plastic battery case and a lid are heat-welded to each other on the outer surfaces of two opposite side walls of the battery case. A cooling plate is formed between the side wall of the battery case and the side plate by heat-welding the side plate on which the cooling plate is formed, and an inlet orifice and an outlet orifice for the cooling liquid are provided on both ends of the side plate. .

In Japanese Patent Application Laid-Open No. 61-45571, a cooling passage penetrating vertically is provided in a partition wall between cells of a monoblock battery case, and a cooling medium flows in and out of the cooling passage.
There is disclosed an arrangement in which a header for discharge is provided, and a lid is provided separately for each cell.

[0005]

However, in the collective sealed secondary battery disclosed in Japanese Patent Application Laid-Open No. H7-85847, since the cells are closely arranged and tightened, when the ambient temperature is high or a large current is applied. When charging and discharging, there is a problem that heat is not sufficiently released from each unit cell, and the battery temperature rises and the battery life is shortened.

On the other hand, in the storage battery disclosed in JP-A-6-215804, the temperature rise can be suppressed to some extent because both sides of the battery case are cooled by the water-cooling jackets. However, as shown in FIG. In the assembled secondary battery, there is a problem that the temperature rise of the unit cells cannot be sufficiently suppressed because the unit cells cannot be cooled particularly.

On the other hand, in the storage battery disclosed in Japanese Patent Application Laid-Open No. 61-45571, portions of the partition between cells in the monoblock battery case where the upper and lower cooling passages are formed are forcibly cooled. The cooling effect is not sufficient because it is not forcibly cooled, and the manufacturing cost is high because the structure of the battery case is complicated, and it is necessary to provide a lid for each cell, which increases the number of assembly steps. There are problems such as an increase in cost.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a collective sealed secondary battery capable of effectively cooling each unit cell at a low cost.

[0009]

Means for Solving the Problems The assembled sealed secondary battery of the present invention comprises a plurality of unit cells each having a power generating element housed in a bottomed rectangular cylindrical battery case and whose opening is sealed. In a collective type sealed secondary battery arranged in series, a cooling medium passage is formed by communicating these between the battery cases of each unit cell and on both sides thereof with respect to the arrangement direction of the unit cells. All the cells, including between the cells, can be forcibly cooled with the cooling medium with the cooling medium passing through the cells, so that all the cells can be cooled effectively.

Further, when the cooling medium passage is provided outside the unit cells at both ends of the collective sealed secondary battery, the outer surfaces of the unit cells at both ends can also be forcibly cooled.

Further, when cooling jacket members are joined to both sides of the unit cells of the assembled type sealed secondary battery with respect to the arrangement direction of the cells and / or to both ends of the unit cells in the arrangement direction, the cooling medium passage is formed into a compact cooling jacket. The member can be easily and lightly configured.

Further, a projection is provided on at least one of the opposing wall surfaces of the battery case of each unit cell, and a cooling medium passage is formed between the opposed wall surfaces. Only by forming the protrusions, a cooling medium passage over substantially the entire surface between the opposed wall surfaces of the unit cell can be formed easily and inexpensively.

[0013] Further, if the cooling medium passage is provided with a rectifying ridge so that the cooling medium flows through the entire surface of the cooling medium passage on both sides in the unit cell arrangement direction, the whole can be cooled reliably and uniformly. High cooling performance can be secured.

Further, when the unit cells are integrally joined to each other and the opening is sealed with an integral lid, an assembled closed secondary battery having an integrated battery case with a small number of parts and assembling steps is obtained. be able to.

Further, when the battery case and the lid of the unit cell, or the battery case, the cover and the cooling jacket member of the unit cell are made of synthetic resin and joined to each other by welding to be integrated, A secondary battery in which unit cells are assembled can be easily obtained as an integrated battery case.

Further, an inlet orifice and an outlet orifice of the cooling medium for supplying and discharging the cooling medium to and from the cooling medium passages on both sides in the unit cell arrangement direction are provided at both ends in the unit cell arrangement direction, and both sides are arranged via the distribution header. Connected to the cooling medium passage, the cooling medium can be supplied and discharged from the single inlet orifice and the single outlet orifice, and the cooling pipe for the secondary battery can be simplified.

Further, when a cooling medium passage is formed between the two battery cells of each cell, the cross-sectional area of one cooling medium passage can be increased with the same overall length, and the pressure loss in the cooling medium passage can be reduced. Can be smaller.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an assembled sealed secondary battery according to an embodiment of the present invention.

The assembled sealed secondary battery 1 of this embodiment is a nickel-metal hydride secondary battery which can be suitably used as a drive power source for an electric vehicle. As shown in FIGS. 2 are connected in series and joined together to form an integrated battery case.
The plate-shaped cooling jacket member 3 having a flat space recessed inward on both sides thereof in the arrangement direction of the end plates 6 is joined, and a single lid 5 is joined thereon, thereby forming each unit cell. The end plate 6 and the end plate 6 are hermetically closed, and the end plate 6 is tightly tightened by a restraining band 7. Reference numeral 8 denotes a terminal mounting hole formed in the lid 5 so that a positive electrode terminal and a negative electrode terminal protruding upward from the cell 2 at one end and the other end penetrate, and 9 denotes a lid 5 corresponding to each cell 2. Is a safety valve mounting hole formed through. 10,
Reference numeral 11 denotes an inlet orifice and an outlet orifice for the cooling medium, which are integrally mounted on both ends of the lid 5. The cell 2, the cooling jacket member 3, the lid 5, the end plate 6, the inlet orifice 10, the outlet orifice 11, and the like are made of a synthetic resin such as a PP / PPE alloy, and are integrally joined to each other by welding. . In addition, adjacent cells 2 and 2
As shown in FIGS. 2 and 3, they are electrically connected by a connector 12.

The cell 2 will be described below in detail. As shown in FIGS. 2 and 3, a power generating element 15 is housed in a battery case 14 having a bottomed rectangular cylindrical shape. On the opposed wall surface 16 of the battery case 14 facing each other in a state of being arranged in series,
A large number of projections 17 that come into contact with each other are provided in a matrix, and the projections 17 define a cooling medium passage 18 in a space formed between the opposed wall surfaces 16.
In addition, the opposing wall surface 16 outside the cell 2 at both ends of the cell row
The end plate 6 is abutted and joined to the, and a cooling medium passage 18 is also formed between the end plate 6 and the opposing wall surface 16.
The end plate 6 may be constituted by a cooling jacket member.
Also, a plurality of (four in the illustrated example) projections 17 at appropriate locations
Are formed with a large diameter, and engagement protrusions 19a and engagement recesses 19b which are fitted and engaged with each other are formed on the end surfaces thereof, so that the battery case 14 is positioned relative to the other. In addition, a joining edge portion 20 that abuts on the lower end edge portion at an appropriate distance from the upper end of the battery case 14 protrudes. Then, in a state where the cells 2 are arranged in series, the projecting portions 17 and the joining edges 20 which are in contact with each other are welded to each other, whereby the cells 2 are integrally joined as an integral battery case.

The space formed between the unit cell 2 and the inner surface of the cooling jacket member 3 on both sides in the arrangement direction of the unit cells 2 forms cooling medium passages 21 on both sides. A distribution header forming gutter 22 is formed on the upper edge of the end plate 6 to communicate with the cooling medium passages 21 on both sides and distribute the cooling medium (water).

An upper frame 26 above the upper joining edge 20 in the battery case 14 of each unit cell 2 formed as an integrated battery case has
As shown in FIGS. 2, 3, and 4, substantially triangular cutouts 13 for arranging connecting bodies 12 for electrically connecting adjacent unit cells 2 are formed in a staggered manner. 1
3 and integrally joined to the battery case 14 and the lid 5 in a sealed state.

As shown in FIGS. 2, 3 and 5, the connecting body 12 is composed of a connecting shaft 27 made of metal (nickel or the like) and a support 28 made of synthetic resin. 28
Of the connection shaft 27 and the inner periphery of the holding cylinder portion 29 and are completely sealed by an O-ring 31 interposed between the flange portion 27a of the connection shaft 27 and the inner periphery of the holding cylinder portion 29. The support 28 has a pair of triangular wings 30 from a holding cylinder 29.
Are arranged so as to be joined to the individual frames 26 when the connecting bodies 12 are arranged in the cutouts 13, respectively.

As shown in FIGS. 2, 3, and 6, the lid 5 has an individual frame 32 formed on the inner surface thereof so as to correspond to the upper frame 26 of each battery case 14, and an inverted cross section on the outer peripheral portion. An outer peripheral frame 33 hangs down in an L-shape, and sealing ridges 34 are formed at both ends in the longitudinal direction and are joined to the upper ends of the distribution header forming gutters 22 to hermetically form the distribution header 35.

A terminal mounting hole 8 is formed on one side of both ends of the lid 5, and a joining ridge 36 for joining the inlet orifice 10 and the outlet orifice 11 is provided on the other side. . These orifices 10 and 11 have a plane shape of substantially J.
The connection port 38 is configured to protrude from the tip of the short side of the J-shaped box piece 37 having a U-shape and open at the bottom. In addition, the lid 5
A communication opening 39 communicating with the distribution header 35 is formed at a portion facing the long side end of the J-shaped box piece 37 of FIG.

As shown in FIG. 7A, a meandering flow passage 40 meandering up and down is formed on the inner surface of the cooling jacket member 3 so that the cooling medium flows evenly over the entire surface of the cooling medium passage 21. A rectifying ridge 41 to be formed is provided so as to protrude.
Instead of the rectifying ridge 41, as shown in FIG.
A plurality of horizontal straightening ridges 42 may be provided at appropriate intervals in the vertical direction at the upper portion, which are shorter at the upper portion and longer at the lower portion. FIG.
As shown in (c), these rectifying ridges 41 and 42 may not be necessarily provided, but in this case, a stagnation area 43 of the cooling medium is generated at the lower part on both sides of the cooling medium passage 21, and the single ends at both ends in the arrangement direction are formed. Since there is a possibility that the lower part of the battery 2 may not be sufficiently cooled, it is desirable to provide the rectifying ridges 41 and 42.
The rectifying ridges 41 and 42 are connected to the battery case 14 of the cell 2.
It may be provided on the side.

In the assembled sealed secondary battery 1 having the above structure, when a cooling medium is supplied from the inlet orifice 10,
The coolant flows into the cooling medium passages 21 on both sides through the distribution header 35, flows downstream in the cooling medium passages 21, and passes through the cooling medium passages 18 between the cells 2. 21, all sides including the opposed wall surface 16 of the battery case 14 of the unit cell 2 are forcibly cooled by the cooling medium, and the cooling medium is thereafter cooled by the outlet orifice 1.
Emitted from 1. Therefore, the four circumferential sides of all the cells 2 are effectively cooled by the cooling medium.

Further, since the unit cells 2 are welded and integrally joined to each other to form an integrated battery case, and an integral lid 5 is welded and sealed to the opening, so that the number of parts is small. The assembly type sealed secondary battery 1 formed as an integrated battery case can be obtained by assembling man-hours. Further, the projecting portion 17 is formed on the opposing wall surface 16 of the battery case 14 of each unit cell 2, and the projecting portion 17 is brought into contact. Therefore, the cooling medium passage 18 extending over substantially the entire surface between the opposed wall surfaces 16 can be formed easily and inexpensively.

Further, since the cooling medium passages 21 on both sides are formed by joining the compact plate-shaped cooling jacket members 3 to both sides of the unit cell array, the weight can be reduced.

The cooling medium inlet orifice 10 for supplying and discharging the cooling medium to and from the cooling medium passages 21 on both sides.
And the outlet orifices 11 are disposed at both ends in the unit cell arrangement direction and are connected to the cooling medium passages 21 on both sides via the distribution header 35. The entire circumference of the battery 2 can be effectively cooled.

In the above description of the embodiment, FIG.
As shown in FIG. 8A, an example in which the cooling medium passage 18 is provided between the cells 2 is shown. However, as shown in FIG. Cooling medium passage 18
May be formed. In this case, the width of the cooling medium passage 18 is changed to t while keeping the overall length L of the secondary battery 1 the same.
To 2t, and the flow path cross-sectional area can be increased, so that the pressure loss in the cooling medium passage 18 can be reduced.

In the above description of the embodiment, an example is shown in which the inlet orifice 10 and the outlet orifice 11 are arranged on one side in a direction orthogonal to the direction in which the cells 2 are arranged.
As shown, the inlet orifice 10 and the outlet orifice 1
The cooling medium 1 may be disposed at a diagonal position so that the cooling medium flows through the cooling medium passage 18 between the cells 2. In the example of FIG. 9A, a meandering passage is formed by the cooling medium passages 21 on both sides and the cooling medium passage 18 between the cells. FIG.
In the example of (b), each cooling medium passage 18 is provided by providing the inlet orifice 10 at one end of the cooling medium passage 21 on one side and the outlet orifice 11 at the other end of the cooling medium passage 21 on the other side.
The cooling medium is allowed to flow through the cooling medium.

In the above embodiment, the lid 5 covers the end plate 6, and the inlet orifice 10 and the outlet orifice 11
In the example shown in FIG. 10, the cover 5 covers only the group of cells 2, and the distribution header 52 is integrated with the upper end of the end plates 6 at both ends as shown in FIG. 10. The cooling orifice 10 and the outlet orifice 11 are protruded from the upper surface thereof, and a connection portion 53 for connecting the internal cooling medium passage 21 to both ends of the distribution header portion 52 is provided at the upper end of both ends of the cooling jacket member 3. It may be bent. The hatched portions in FIG. 10 are the assembly of the unit cells 2 and the welded portion 54 of the cooling jacket member 3.

In this embodiment, basically, the same operation and effect as those of the above embodiment can be obtained.

Further, in the above-described embodiment, an example has been shown in which the constituent members are integrally joined by welding, but they may be integrally joined with an adhesive.

[0036]

According to the collective sealed secondary battery of the present invention,
As is clear from the above description, the cooling medium passages are formed by connecting these between the battery cases of each unit cell and both sides thereof with respect to the arrangement direction of the unit cells, and pass through these cooling medium passages. Since the cooling medium can forcibly cool all sides of the single cell including the single cells with the cooling medium, all the single cells can be effectively cooled.

Further, when the cooling medium passages are provided outside the unit cells at both ends of the collective sealed secondary battery, the outer surfaces of the unit cells at both ends can also be forcibly cooled.

When the cooling jacket members are joined to both sides of the unit cells of the assembled sealed secondary battery with respect to the arrangement direction of the cells and / or to both ends of the unit cells in the arrangement direction, the cooling medium passage is connected to the cooling jacket members. And can be formed easily and lightly.

Further, a projecting portion is provided on at least one of both opposing wall surfaces of the battery case of each unit cell, and a cooling medium passage is formed between both wall surfaces. Only by forming the protrusions, a cooling medium passage over substantially the entire surface between the opposed wall surfaces of the unit cell can be formed easily and inexpensively.

Further, by providing a rectifying ridge in the cooling medium passage so that the cooling medium flows through the entire surface of the cooling medium passages on both sides, the entire cooling can be surely and uniformly cooled, and high cooling performance can be achieved. Can be secured.

Further, when the unit cells are integrally joined to each other and the opening is sealed with an integral lid, a collective sealed secondary battery having an integrated battery case with a small number of parts and man-hours is obtained. be able to.

Further, when the battery case and lid of the unit cell, or the battery case, lid and cooling jacket member of the unit cell are made of synthetic resin and are alternately joined by welding to be integrated, A secondary battery in which unit cells are assembled can be easily obtained as an integrated battery case.

Further, cooling medium inlet and outlet orifices for supplying and discharging the cooling medium to and from the cooling medium passages on both sides are disposed at both ends in the cell arrangement direction, and the cooling medium passages on both sides are arranged via distribution headers. The cooling medium can be supplied and discharged from the single inlet orifice and the single outlet orifice, and the cooling battery piping for the secondary battery can be simplified.

When a cooling medium passage is formed between two battery cells of each cell, the cross-sectional area of one cooling medium passage can be increased with the same overall length, and the pressure loss in the cooling medium passage can be reduced. Can be smaller.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an embodiment of a collective sealed secondary battery of the present invention.

FIG. 2 is a vertical sectional side view of the embodiment.

FIG. 3 is a partial vertical sectional front view of the embodiment.

FIG. 4 is a partial perspective view of the intermediate lid of the embodiment.

FIG. 5 is a perspective view of the electric connection body of the embodiment.

FIG. 6 is a perspective view of the lid according to the embodiment.

FIG. 7 is a longitudinal sectional view showing various configuration examples in the cooling medium passages on both sides of the embodiment.

FIG. 8 is a schematic cross-sectional plan view showing an arrangement state of a cooling medium passage and a modification thereof in the embodiment.

FIG. 9 is a schematic cross-sectional plan view of a flow path configuration example that forms another flow of the cooling medium in the embodiment.

FIG. 10 is an exploded perspective view of another embodiment of the collective sealed secondary battery of the present invention.

FIG. 11 is a front view of a conventional collective sealed secondary battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Set-type sealed secondary battery 2 Single cell 3 Cooling jacket member 5 Lid 10 Inlet orifice 11 Outlet orifice 14 Battery case 15 Power generation element 16 Opposite wall surface 17 Projection 18 Coolant passage 21 Coolant passage on both sides 35 Distribution header 41 Rectification Ridge 42 straightening ridge

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinsuke Fukuda 555 Sakaijuku, Kosai-shi, Shizuoka Prefecture Inside Panasonic EV Energy Co., Ltd. (72) Inventor Shinichi Yuasa 555 Sakaijuku, Kosai-shi, Shizuoka Prefecture Inside Panasonic EV Energy ( 72) Inventor Shinji Hamada 555 Sakaijuku, Kosai-shi, Shizuoka Prefecture F-term in Panasonic EV Energy Co., Ltd. (reference) 5H020 AS06 CC06 CC13 KK13 5H031 AA09 BB03 EE04 KK08

Claims (10)

[Claims] 1. An assembled closed secondary battery in which a plurality of cells each having a power generating element housed in a bottomed rectangular cylindrical battery case and whose opening is sealed are arranged in series, a cooling medium passage is provided. An integrated sealed secondary battery, wherein the battery is formed by connecting the cells between battery cases and on both sides of the unit cell in the arrangement direction thereof. 2. The collective sealed secondary battery according to claim 1, wherein the cooling medium passages are provided outside the unit cells at both ends of the collective sealed secondary battery. 3. A cooling jacket member is joined to both sides of the united sealed secondary battery with respect to the unit cell arrangement direction and / or both ends in the unit cell arrangement direction. A collective sealed secondary battery as described in the above. 4. A cooling medium passage is formed between at least one of the opposed wall surfaces of the battery case of each of the unit cells.
4. The collective sealed secondary battery according to any one of 3. 5. The cooling medium passage according to claim 3, wherein a straightening ridge is provided in the cooling medium passage so that the cooling medium flows through the entire surface of the cooling medium passage on both sides in the unit cell array direction. 2. The assembled sealed secondary battery according to 1. 6. The collective sealed secondary battery according to claim 1, wherein the unit cells are integrally joined to each other, and the opening is sealed with an integrated lid. . 7. The collective sealed secondary battery according to claim 6, wherein the battery case and the lid of the unit cell are made of synthetic resin and joined together by welding to be integrated. 8. The collective hermetically sealed secondary according to claim 6, wherein the battery case, lid and cooling jacket member of the unit cell are made of synthetic resin and joined together by welding to be integrated. battery. 9. An inlet orifice and an outlet orifice of a cooling medium for supplying and discharging a cooling medium to and from a cooling medium passage on both sides in the unit cell arrangement direction are arranged at both ends in the unit cell arrangement direction and both sides via a distribution header. The collective sealed secondary battery according to any one of claims 1 to 3, wherein the battery is connected to the cooling medium passage. 10. A cooling medium passage formed between two battery cells of each battery case.
4. The collective sealed secondary battery according to any one of 3.