The present invention relates to a cell block (battery block) including a plurality of cells connected to each other.
In order to form a battery block by connecting a plurality of cells to each other, an interconnecting member, a case, and the like, in addition to a plurality of cells, are necessary, and it is desirable that they can be assembled and disassembled easily.
PTL 1 discloses a battery system including a plurality of cells positioned and interconnected without welding. The battery system disclosed herein includes a separator case having columnar portions and in which a plurality of cells are aligned, and contact-holding panels confronting electrodes of the cells on the upper and lower parts of the separator case, respectively. The contact-holding panels include a frame, a contact strip held by a hook provided to the frame, and blades that are in contact with the electrodes of the cells and provided to the contact strip. The blades are urged by a coil spring provided to the frame, and pressed against the electrodes. The contact-holding panels are fixed to the plurality of columnar portions of the separator case by screws, respectively.
PTL 1: Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2010-538435
It is desired that a battery block formed by connecting a plurality of cells to each other can be disassembled easily, so that the cells and other component elements can be recycled.
A battery block in accordance with the present invention includes a plurality of cells, each having a safety valve, aligned in such a manner that a safety valve side is arranged to a first side along a longitudinal direction of the cells, where the safety valve side is a side having the safety valve; a positive electrode plate part provided at a positive electrode side of the cells and a negative electrode plate part provided at a negative electrode side of the cells in order to connect the plurality of cells in parallel; and a duct cover covering the safety valve side of the cells and constituting a duct chamber for exhausting exhaust gas discharged from the safety valve. The positive electrode plate part or the negative electrode plate part corresponding to the safety valve side is an elastic electrode plate part that is in elastic contact with a positive electrode or a negative electrode which is a safety-valve-side electrode corresponding to the safety valve side. The duct cover is integrated with the elastic electrode plate part while pressing the elastic electrode plate part against the safety-valve-side electrode at a predetermined pressing pressure, with attractive force for attracting the duct cover and the elastic electrode plate part to each other.
According to the present invention, a battery block can be easily disassembled by removing attractive force, and the cells and other component elements can be recycled.
Hereinafter, exemplary embodiments of the present invention are described in more detail. The following material, dimension, shape and number of cells, and the like, are mere examples and may be appropriately modified depending upon the specifications of a battery block. Hereinafter, the same reference numerals are given to the corresponding components in all drawings, and description thereof is omitted.
Battery block 1 houses cell assembly 4 inside insulating case 5. Battery block 1 can be made attachable to, for example, an attachment plate for attaching a storage battery device (not shown), by using attachment members 2 and 3.
Attachment members 2 and 3 are not component elements of battery block 1, but they are members disposed along the outer periphery of insulating case 5, and attached to an attachment plate for attaching a storage battery device (not shown) by an appropriate fastening member. Thus, attachment members 2 and 3 press and integrate cells so that the cells of battery block 1 are not separated from each other. In other words, by removing attachment members 2 and 3 from battery block 1, battery block 1 can be disassembled easily. Examples of such attachment members 2 and 3 include bending plate material that has been processed from appropriate metallic material into a predetermined shape. Examples of the fastening member include a bolt, a screw, and the like.
Insulating case 5 is a case made of electrically insulating material and housing cell assembly 4 inside thereof. Insulating case 5 is made by combining lower case 6 and upper case 7 with each other. Therefore, when upper case 7 is taken off from lower case 6, cell assembly 4 can be taken out easily. Insulating case 5 is configured to integrate component elements of cell assembly 4 together and to electrically isolate a conductive part including cell assembly 4 and positive and negative electrode parts thereof from the outside. As such an insulating case 5, a case formed by molding plastic material having heat resistance property and electric insulation property into a predetermined shape can be used. Examples of the plastic material include polyethylene terephthalate, polyimide, polysulfone, polyether sulfone, polyetherimide, polyphenylene sulfide, polyether ether ketone, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, and the like.
As shown in
As the secondary cell, a lithium ion cell is used. In addition to this, a nickel metal-hydride cell, an alkaline cell, or the like, may be used. Cell 9 has a cylindrical outer shape. One of the both ends of the cylindrical cell is used as positive electrode terminal 16 and the other end is used as negative electrode terminal 17. One example of each cell 9 is a lithium ion cell having a diameter of 18 mm, height of 65 mm, a voltage between terminals of 3.6 V, and capacity of 2.5 Ah. This is an example for description, and cell 9 may have any other shapes, dimensions, and property values. For example, cell 9 may be a rectangular cell.
Each of cells 9 includes safety valve 14. Safety valve 14 is a mechanism for releasing gas as exhaust gas from the inside of cell 9 to the outside when a pressure of gas generated by electrochemical reaction occurring inside cell 9 exceeds a predetermined threshold pressure. Safety valve 14 is disposed at the negative electrode side of cell 9.
When a side having safety valve 14 is defined as a safety valve side, cells 9 are aligned in such a manner that the safety valve side is arranged to one side along the longitudinal direction of cells 9. The one side is a direction in which duct cover 10 of cell assembly 4 is provided.
The reason why the safety valve sides are arranged to the side provided with duct cover 10 in this way is because exhaust gas is discharged to the outside of battery block 1 through duct chamber 15 formed by duct cover 10 when the exhaust gas is discharged from safety valve 14. In this case, since safety valve 14 is provided at the negative electrode side of each cell 9, the negative electrode sides of cells 9 are arranged to one side that is the direction in which duct cover 10 is provided. Therefore, negative electrode terminal 17 of cell 9 is a safety-valve-side electrode. In the case of a cell provided with safety valve 14 at a positive electrode side, the positive electrode sides of cells 9 are arranged to the one side that is the direction in which duct cover 10 is disposed. At such a time, positive electrode terminal 16 is a safety-valve-side electrode.
Positive electrode plate part 11 is a member for connecting thirty-two cells 9 to each other in parallel. A detailed configuration of positive electrode plate part 11 is described later.
Arrangement container 8 shown in
Negative electrode plate part 12 is a member for connecting negative electrode terminals 17 of thirty-two cells 9 to each other in parallel. As shown in
Insulating plate 19 has openings 21 in positions corresponding to negative electrode terminals 17 that are safety-valve-side electrodes of thirty-two cells 9. Insulating plate 19 electrically insulates thirty-two cells 9 from each other. Examples of such insulating plate 19 include a plate made of glass-fiber-containing epoxy resin plate material having openings 21. Instead of glass-fiber-containing epoxy resin, the same material as that of insulating case 5 may be used.
Negative-electrode-side current collector plate 20 is disposed on the upper surface of insulating plate 19 and is made of conductive plate material having thirty-two elastic annular parts 22. Thirty-two elastic annular parts 22 are respectively brought into elastic contact with negative electrode terminals 17 as safety-valve-side electrodes of thirty-two cells 9 through openings 21 of insulating plate 19. The upper surface of insulating plate 19 is a surface facing duct cover 10.
In a plate-like negative-electrode-side current collector plate 20, elastic annular parts 22 are provided such that a portion corresponding to each of openings 21 of insulating plate 19 is projected toward insulating plate 19 by press-molding so as to open the middle thereof. The projected amount is set such that when elastic annular part 22 is brought into contact with negative electrode terminal 17 of cells 9, contact resistance therebetween is in a predetermined range. Managing the contact resistance in a predetermined range can be carried out by, for example, managing whether or not the pressing force given to negative electrode terminal 17 falls within a predetermined pressing force range when elastic annular part 22 is pressed to negative electrode terminal 17 by elasticity.
The lower limit of the range of the pressing force can be pressing force when contact resistance between negative-electrode-side current collector plate 20 and negative electrode terminal 17 is a predetermined threshold value of the contact resistance. The upper limit can be pressing force when stress occurring in elastic annular part 22 becomes elastic critical stress. The thickness as that elastic annular part 22 is substantially the same thickness as that of negative-electrode-side current collector plate 20. An example of the thickness of negative-electrode-side current collector plate 20 is about 1 mm to about 2 mm. Therefore, elastic annular part 22 can generate appropriate elastic force, that is, pressing force with respect to negative electrode terminal 17.
Examples of such a negative-electrode-side current collector plate 20 include a metal plate that has been processed into a predetermined shape and provided with elastic annular parts 22. Examples of material of the metal plate include phosphor bronze, stainless steel, nickel, nickel-iron alloy, copper, aluminum, or the like. If necessary, it is preferable that a part of elastic annular part 22 is coated with conductive grease or the like. Elastic annular part 22 may be, for example, gold-plated.
Since negative-electrode-side current collector plate 20 is provided with a plurality of elastic annular parts 22, it has a function of electrically connecting these elastic annular parts 22 in parallel and collecting current.
Insulating holding part 13 is a member for securing electrical insulation between negative-electrode-side current collector plate 20 of negative electrode plate part 12 and duct cover 10. As shown in
Duct cover 10 is a component covering the safety valve side of cell assembly 4 and forming duct chamber 15. Duct chamber 15 allows exhaust gas to flow along the end portion at the negative electrode side of cell assembly 4. Duct cover 10 includes ceiling part 27 and leg parts 28 and 29 extending downward from the both sides of ceiling part 27, and has a rectangular U-shape or a C-shape that opens downward. Use of duct chamber 15 enables exhaust gas discharged from safety valve 14 to be discharged from a predetermined exhaust hole to the outside of battery block 1 through duct chamber 15 without being leaked to other places. As such a duct cover 10, a cover, which has been processed from metal or other material having predetermined heat resistance and strength into a predetermined shape, can be used.
Next, pressing force given by negative electrode plate part 12 as an elastic electrode plate part to negative electrode terminal 17 in battery block 1 is described with reference to
As shown in
As shown in
Furthermore, fixing power F generates attractive force for attracting duct cover 10 and negative electrode plate part 12 confronting duct cover 10 to each other. With this attractive force, duct cover 10 is integrated with the elastic electrode plate part while pressing negative electrode plate part 12 as the elastic electrode plate part against negative electrode terminal 17 as the safety-valve-side electrode with predetermined pressing pressure. That is to say, duct cover 10 presses negative electrode plate part 12 toward negative electrode terminals 17 of cells 9 via insulating holding part 13. Negative electrode plate part 12 is a laminated body of insulating plate 19 and negative-electrode-side current collector plate 20. From the bottom surface of the laminated body, thirty-two elastic annular parts 22 protrude. Therefore, fixing power F is given as dispersion force, that is, pressing force f by which each of thirty-two elastic annular parts 22 presses negative electrode terminal 17. Pressing force f has magnitude of F/32 according to calculation, but individual pressing force f of each elastic annular part 22 is not F/32 due to, for example, variations of thirty-two elastic annular parts 22. With the variations of thirty-two elastic annular parts 22 or the like taken into account, pressing force f of each of elastic annular parts 22 is set such that the contact resistance between negative-electrode-side current collector plate 20 and negative electrode terminal 17 becomes a predetermined threshold value or less.
An opening in the middle of elastic annular part 22 shown in
Similar to negative electrode plate part 12, positive electrode plate part 11 is a member for connecting negative electrode terminals 17 of thirty-two cells to each other in parallel. As shown in
Sealing plate 50 is disposed on the positive electrode side of cells 9. Sealing plate 50 is connected to each of the positive electrodes inside cells 9 and has positive potential of cell 9. Opening edge portion 52 of battery can 51 having negative potential of cell 9 is pressed and bent. Sealing plate 50 is fixed to battery can 51 by gasket 53 as insulating material. The middle part of sealing plate 50 is protrusion-shaped positive electrode terminal 16. In this way, in the positive electrode side of cell 9, the middle part of sealing plate 50 protrudes as positive electrode terminal 16, and the surrounding thereof is surrounded by opening edge part 52 which is pressed and bent portion of battery can 51 insulated by gasket 53. Opening edge portion 52 of battery can 51 corresponds to the case of cell 9, and has a firm strength.
Insulating plate 41 of positive electrode plate part 11 is insulating plate material similar to insulating plate 19 used for negative electrode plate part 12. Insulating plate 41 is provided with openings 44 at positions corresponding to positive electrode terminals 16 of thirty-two cells 9, respectively. As such insulating plate 41, insulating material, which is the same material as that of insulating plate 19 of the negative electrode side and is molded in a predetermined shape, can be used.
Positive electrode contact plate 42 is a flexible circuit board in which conductive wiring 46 is disposed on flexible resin sheet 45. As shown in (b), conductive wiring 46 includes positive electrode contact part 47 and fuse 48 from which resin sheet 45 has been removed, and is electrically connected to positive-electrode-side current-collector plate 43.
Positive electrode contact part 47 is bent so as to protrude from resin sheet 45 toward the positive electrode terminal 16 side. Positive electrode contact part 47 can pass through opening 44 in insulating plate 41 and be brought into contact with positive electrode terminal 16, and is connected and fixed to positive electrode terminal 16 by, for example, welding. Fuse 48 is a safety device obtained by forming conductive wiring 46 into a narrow and long shape and has a moderately high resistance value. Fuse 48 is melted and cut when an excessive amount of electric current flows therein. Examples of such positive electrode contact part 47 include a polyimide resin sheet on which a copper foil is wired.
Positive-electrode-side current-collector plate 43 is conductive plate material provided with appropriate opening 49 at a position corresponding to a position in which positive electrode contact part 47 of positive electrode contact plate 42 and fuse 48 are disposed. Presence of providing of opening 49 can prevent fuse 48 from being brought into contact with and short-circuited to positive-electrode-side current-collector plate 43. Furthermore, positive-electrode-side current-collector plate 43 is electrically connected to thirty-two positive electrode contact parts 47 via fuse 48, and positive electrode contact parts 47 are connected to corresponding positive electrode terminals 16 by, for example, welding. Accordingly, positive electrode contact parts 47 have a function of electrically connecting positive electrode sides of thirty-two cells 9 in parallel and collecting current. As such positive-electrode-side current-collector plate 43, a plate formed by molding a metal conductive plate having an appropriate thickness into a predetermined shape can be used. Examples of the metal material include aluminum, copper, nickel, and an ally of iron and nickel.
As shown in
Thus, fixing power F is given to insulating case 5 by attachment members 2 and 3, and fixing power F fixes duct cover 10 to the inside of insulating case 5. Fixing power F generates attractive force for attracting duct cover 10 to negative electrode plate part 12 confronting duct cover 10. The attractive force allows duct cover 10 to be integrated with negative-electrode-side current collector plate 20. Then, with fixing power F, duct cover 10 presses elastic annular part 22 as the elastic electrode plate part of negative electrode plate part 12 to negative electrode terminal 17 as the safety-valve-side electrode with pressing force f exceeding a predetermined threshold pressing pressure. This ensures electrical conduction between negative electrode terminals 17 of cells 9 and negative electrode plate part 12.
Then, when attachment members 2 and 3 are taken off from the attachment plate, the attractive force for attracting duct cover 10 and negative electrode plate part 12 confronting duct cover 10 is removed.
Accordingly, the component elements can be easily separated from each other and disassembled. That is to say, insulating case 5 is divided into lower case 6 and upper case 7, and cell assembly 4 can be taken out from lower case 6. In this state, since duct cover 10 is not fixed to insulating case 5, duct cover 10, negative-electrode-side current collector plate 20 constituting negative electrode plate part 12, and insulating plate 19 can be disassembled sequentially. When arrangement container 8 is taken off, thirty-two cells 9 fixed to positive electrode plate part 11 appear downward from cell-containing portion 18 of arrangement container 8.
Furthermore, positive electrode terminal 16 of cell 9 is connected and fixed to positive electrode contact part 47 via fuse 48 by, for example, welding.
By cutting fuse 48 by an external pressure, thirty-two cells 9 fixed to positive electrode plate part 11 can be separated from positive electrode plate part 11. In order to cut fuse 48 by an external pressure, it is preferable that fuse 48 has such strength that can be cut by a cutter or the like, and such tensile strength that can be cut when positive electrode plate part 11 and cell 9 are drawn in the opposite directions.
In this way, by removing attachment members 2 and 3, and removing the fixture of duct cover 10 by insulating case 5, battery block 1 can be easily disassembled into each component element.
In the above configuration, with fixing power F for attaching battery block 1 to the attachment plate, duct cover 10 is integrated with negative electrode plate part 12 while pressing negative electrode plate part 12 as the elastic electrode plate part against negative electrode terminal 17 as the safety-valve-side electrode at a predetermined pressing pressure. Instead, a duct cover and an insulating case can be integrated with each other by using a fixing member, and, with tightening force thereof, duct cover 10 can be integrated with negative electrode plate part 12, while pressing negative electrode plate part 12 against negative electrode terminal 17 at a predetermined pressing pressure.
Battery block 60 shown in
Duct cover 61 is provided with flange portions at the both sides in the width direction in order to attach fixing screws 63. Insulating case 62 is a pipe-shaped member having a bottom and opening at a duct cover 61 side.
In insulating case 62, upper case 7 shown in
In the above configuration, the attractive force for attracting duct cover 61 and negative electrode plate part 12 as the elastic electrode plate part to each other is given via insulating cases 5 and 62. However, the attractive force for attracting duct cover 61 and negative electrode plate part 12 as the elastic electrode plate part to each other may be given only by cell assembly 4.
Insulating columnar portion 74 is insulating material constituting the integrating means and being disposed between positive electrode plate part 11 as a rear-side electrode part and duct cover 71. Insulating columnar portion 74 is provided so as to secure insulation when duct cover 71 and positive electrode plate part 11 are integrated with each other. Insulating columnar portion 74 includes first columnar portions 75 replaced with some of the plurality of cells 9 housed in arrangement container 8 and second columnar portion 76 integrated with first columnar portions 75 and extending toward duct cover 71. Positive electrode plate part 11 side of first columnar portion 75 is provided with a screw hole corresponding to positive-electrode-plate-side attachment screw 73. Duct cover 71 side of second columnar portion 76 is provided with a screw hole corresponding to cover-side attachment screw 72.
Rivet 83 includes rivet main body 84, cover-side head portion 82, positive-electrode-side head portion 85 at the positive electrode plate side, and insulating part 86 for covering positive-electrode-side head portion 85. Insulating part 86 is used to secure insulation along with insulating holding part 13 when duct cover 81 and positive electrode plate part 11 are integrated with each other. Rivet main body 84 is provided not to a position of the cell-containing portion that is an opening for housing cells 9 in arrangement container 8, but to a portion including material constituting arrangement container 8. Through-hole 87 through which rivet main body 84 is allowed to pass is provided. As such a rivet 83, a rivet called a blind rivet, which is capable of rivet operation on one side of positive electrode plate part 11 side or the duct cover 81 side, can be used.
The rivet operation can be carried out as follows. Rivet material before the rivet operation is thin wire material having a predetermined length and provided with a head portion at one end and a thin head counterpart before operation at the other end. The head counterpart is provided with an insulating cover as an insulating part in advance. This rivet material is disposed at the duct cover 81 side, for example, in a state in which the head portion is located at cover-side head portion 82. The head counterpart and a thin wire material part are allowed to pass through through-hole 87 of arrangement container 8, and the head counterpart is allowed to protrude at positive electrode plate part 11 side. The protruding head counterpart having the insulating cover is drawn by using a rivet operation tool, so that positive-electrode-side head portion 85 having insulating part 86 is formed. Thus, duct cover 81 and positive electrode plate part 11 are integrated with each other while insulation is secured.
When the attractive force for attracting the duct cover and negative electrode plate part 12 as the elastic electrode plate part to each other is insufficient, variation may occur in the electrical contact between negative electrode terminal 17 and negative electrode plate part 12 in the plurality of cells 9 depending on places. In order to suppress the variation, a pressing member for pressing lifting of the elastic electrode plate part may be provided between the duct cover and the upper surface of negative electrode plate part 12 as the elastic electrode plate part covered with the duct cover.
Battery block 1 shown in
Battery block 1 shown in
Rib 91 partially extends in the width direction of duct cover 10, and is brought into contact with negative electrode plate part 12 on the bottom surface thereof. Rib 91 includes projected part 92 integrated with duct cover 10 and insulating member 93 provided on the bottom surface of projected part 92. Similar to insulating holding part 13, insulating member 93 is used to secure insulation between duct cover 10 and negative electrode plate part 12.
Note here that the pressing member is not necessarily limited to a member, such as projected part 92 of rib 91, integrated with duct cover 10. For example, insulating holding part 13 shown in
In the above configuration, in order to align cells 9, arrangement container 8 is used. However, arrangement container 8 may be occasionally omitted. A shape of the inner wall of insulating case 5 can be made so as to be suitable for aligning, so that a plurality of cells 9 is aligned by using the shape of the inner wall.
In the above configuration, safety valve 14 is provided in the vicinity of negative electrode terminals 17 of cells 9, and duct cover 10 is configured to press negative electrode plate part 12. When safety valve 14 is provided in the vicinity of positive electrode terminals 16 of cells 9, the structure of
In the above configuration, insulating plates 19 and 41 are not necessarily limited to a plate shape. For example, insulating plates 19 and 41 may be provided with a holder part for holding a part of cells 9 or arrangement container 8.
In the above configuration, arrangement container 8 is a framework body provided with thirty-two cell-containing portions 18 opening at both end sides in the height direction. However, as long as a holding container which holds cells 9 in a state in which cells 9 are aligned in a predetermined arrangement relation, each of cell-containing portions 18 provided in arrangement container 8 is not necessarily a container for housing one cell.
By the way, battery block 1 is required to be small in size in order to increase the amount thereof to be mounted on a vehicle or to reduce space for a storage battery device.
Cell-containing portion 18 of
Number | Date | Country | Kind |
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2013-073918 | Mar 2013 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2014/001434 | 3/13/2014 | WO | 00 |