WO2012057169A1

WO2012057169A1 - Power-supply device, vehicle using same, battery cell, and battery-cell manufacturing method

Info

Publication number: WO2012057169A1
Application number: PCT/JP2011/074593
Authority: WO
Inventors: 康広浅井
Original assignee: 三洋電機株式会社
Priority date: 2010-10-26
Filing date: 2011-10-25
Publication date: 2012-05-03

Abstract

A power-supply device provided with a fastening means for fastening together a plurality of battery cells (1) stacked with separators (2) interposed therebetween. Each battery cell (1) is provided with: a rectangular outer casing (12) comprising a top surface (24), a bottom surface (23), a pair of principal surfaces (21), and a pair of side surfaces (22); a tubular insulating film sheath (20) that covers the principal surfaces (21) and side surfaces (22) of the outer casing (12); and an insulating insulation layer (30) that covers the bottom surface (23) of the outer casing (12). Said insulation layer (30) is obtained by coating the outer casing so as to tightly cover the entire bottom surface (23) of the outer casing (12), stretch from said bottom surface (23) to the principal surfaces (21) and side surfaces (22), and overlap at least part of the bottom edge of the film sheath. With the respective bottom surfaces (23) of the plurality of battery cells (1) in roughly the same plane, the fastening means can fasten said battery cells together in a stack.

Description

Power supply device, vehicle using the same, battery cell, and battery cell manufacturing method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a power supply device for a large current used for a power source of a motor driving a vehicle such as a hybrid vehicle or an electric vehicle, and a vehicle, a battery cell, and a battery cell manufacturing method using the same.

An automobile such as an electric vehicle that runs on a motor or a hybrid vehicle that runs on both a motor and an engine is equipped with a power supply device in which a battery cell is housed in an outer case (see, for example, Patent Document 1). This power supply device is a battery block in which a large number of battery cells 1X are connected in series to increase the output voltage, as shown in FIGS. As shown in FIG. 23, each battery cell 1 </ b> X has a square outer can 12 and is provided with positive and negative electrode terminals 13 at the upper end.

A high output lithium ion secondary battery is often used for the battery cell 1X. Since the outer can 12 of the lithium ion secondary battery has an intermediate potential, the surface of the battery cell 1X has a high potential, and this needs to be insulated from the ground of the outer case. For this reason, insulation measures such as covering the outer can 12 of the battery cell 1X with an insulating cover or an insulating sheet are taken. In addition, the battery cell 1X is waterproof.

Generally, as shown in FIG. 24, the top surface 24 of the battery cell 1X is covered with a bag-shaped heat shrinkable sheet 20X so as to expose the electrode terminal 13 on the upper part of the battery cell 1X. Specifically, the heat-shrinkable sheet 20X having a cylindrical opening at the top and the bottom is cut with an appropriate length, and the battery cell 1X is inserted from one opening end as shown in FIG. As shown in b), the heat-shrinkable sheet 20X is heat-shrinked and brought into close contact with the surface of the outer can 12 as shown in FIG. At this time, the heat shrinkable tubes are thermally welded to each other at the bottom surface 23 of the battery cell 1X to close the opening, and the blank portion is cut as necessary to cover the surface of the battery cell 1X with the heat shrinkable tube. It was.

In this method, as shown in the cross-sectional view of FIG. 24C, the heat shrinkable tube protrudes from the bottom surface 23 of the battery cell 1X, so that the bottom surface 23 of the battery cell 1X becomes uneven. As a result, when a plurality of battery cells 1X are stacked and tightly attached with a bind bar or the like to form a battery stack, the bottom surfaces 23 of the battery cells 1X do not line up on the same plane. For this reason, the top surface 24 of each battery cell 1X does not necessarily coincide, and when the electrode terminals 13 protruded from the top surface 24 of the battery cell 1X are fixed with a bus bar or the like, the plurality of electrode terminals 13 are the same. Since they do not align on a flat surface, there is a problem that the contact surface with the bus bar is not uniform and the contact state is not constant. In addition, when cooling from the bottom by bringing the bottom surface of the battery cell into contact with the cooling plate, if the bottom surface of the battery cell is not constant, the contact state with the cooling plate for each battery cell is not constant, and the cooling capacity can be demonstrated. Disappear.

JP 2009-170258 A

The present invention has been made in order to solve the conventional problems as described above. The main object of the present invention is to make the bottom surfaces of the battery cells uniform and to make the bottom surfaces coincide with each other. It is an object of the present invention to provide an easy power supply device, a vehicle, a battery cell, and a battery cell manufacturing method using the same.

Means for Solving the Problems and Effects of the Invention

In order to achieve the above object, according to the power supply device of the first aspect of the present invention, a plurality of battery cells 1 whose outer shape is a rectangular shape whose thickness is thinner than a width, and the plurality of battery cells A separator 2 for insulating the battery cells 1 by interposing them on the surface where the ones are stacked, and a fastening means for stacking and fastening the plurality of battery cells 1 with the separators 2 interposed The battery cell 1 includes a top surface 24, a bottom surface 23, a rectangular outer can 12 including a pair of main surfaces 21 and side surfaces 22, and a main surface of the outer can 12 respectively. 21 and a cylindrical insulating coating film 20 that covers the side surface 22 and an insulating insulating layer 30 that covers the bottom surface 23 of the outer can 12. The insulating layer 30 is provided on the outer can 12. While covering the entire surface of the bottom surface 23 in close contact, It extends from the bottom surface 23 to the main surface 21 and the side surface 22 and is coated so as to overlap at least a part of the lower end edge of the covering film, and the bottom surfaces 23 of the plurality of battery cells 1 are substantially on the same plane. It can be fastened in a stacked state by the fastening means in a lined posture. Thus, the bottom surface of the battery cell is completely insulated to prevent water from entering from the bottom surface, and by making the bottom surface substantially planar, the bottom surface can be easily aligned on the same surface when the battery cells are stacked.

Moreover, according to the power supply device according to the second aspect, the cooling plate 7 can be provided which is further provided with a refrigerant pipe 26 arranged in a thermally coupled state with the bottom surface 23 of the outer can 12. Thereby, the battery cell can be cooled from the bottom surface side, and in particular, the battery cell can be efficiently and uniformly cooled by positioning the bottom surface on substantially the same plane.

Furthermore, according to the power supply device according to the third aspect, the cooling plate 7 and the outer can 12 are made of metal, and the insulating plate that separates the cooling plate 7 from the bottom surface 23 of the outer can 12 is provided. A spacer 40 can be provided. Thereby, a metal exterior can and a cooling plate are physically insulated and the situation where several exterior cans are short-circuited with a cooling plate can be avoided effectively.

Furthermore, according to the power supply device according to the fourth aspect, the separator 2 is provided with the rib 41 that partially covers the bottom surface 23 of the battery cell 1 in a state where the separator 2 is in contact with the battery cell 1. The rib 41 is interposed between the bottom surface 23 of the battery cell 1 and the cooling plate 7 to separate them. Thereby, the conduction of the battery cell by the cooling plate can be avoided by providing the rib as a spacer on the separator.

Furthermore, according to the power supply device according to the fifth aspect, the lower edge of the covering film 20 can be positioned on the main surface 21 and the side surface 22 without protruding from the bottom surface 23 of the outer can 12. Thereby, the situation where a coating film protrudes from the lower surface of a battery cell and the battery cell bottom face does not become flat can be avoided.

Furthermore, according to the power supply device according to the sixth aspect, the covering film 20 can be a heat shrinkable tube. Thereby, a coating film can be easily attached to an exterior can.

Furthermore, according to the vehicle including the power supply device according to the seventh aspect, the above power supply device can be provided.

Furthermore, according to the battery cell which concerns on an 8th side surface, the external shape which consists of the top | upper surface 24 and the bottom face 23, and each pair of main surface 21 and the side surface 22 is made into the square shape which made thickness thinner than the width | variety. An outer can 12, a cylindrical insulating coating film 20 that covers the main surface 21 and the side surface 22 of the outer can 12, and an insulating insulating layer 30 that covers the bottom surface 23 of the outer can 12. The lower end edge of the covering film 20 is not projected from the bottom surface 23 of the outer can 12, but is located on the main surface 21 and the side surface 22, and the insulating layer 30 covers the entire bottom surface 23 of the outer can 12. In addition to being coated in a close contact state, the film can be coated so as to extend from the bottom surface 23 to the main surface 21 and the side surface 22 and to overlap at least part of the lower edge of the coating film. Thereby, while covering the bottom face of a battery cell in a completely insulated state and preventing water from entering from the bottom face, the bottom face can be made to be the same plane when the battery cells are stacked by making the bottom face substantially flat.

Furthermore, according to the method for manufacturing the power supply device according to the ninth aspect, the plurality of battery cells 1 having the outer shape of the outer can formed into a rectangular shape whose thickness is thinner than the width, and the plurality of battery cells 1 are combined. Separator 2 for insulating between the battery cells 1 interposed between the surfaces to be stacked, and fastening means for stacking and fastening the plurality of battery cells 1 with the separators 2 interposed therebetween. A method of manufacturing a power supply apparatus comprising: a cylindrical covering film 20 into which the outer can 12 including a top surface 24 and a bottom surface 23 and a pair of main surfaces 21 and side surfaces 22 can be inserted; Inserting the can 12 and thermally shrinking the covering film 20 in a state where the lower end edge of the covering film 20 is positioned on the main surface 21 and the side surface 22 without protruding from the bottom surface 23 of the outer can 12. Uncured liquid insulating resin 3 The battery cell 1 is filled in a resin tank 32 filled with a liquid from the bottom surface 23 to at least the entire bottom surface 23 of the battery cell 1, the main surface 21, and the side surface 22, and the coating film 20 is liquid so as to include the lower end A step of impregnating the insulating resin 31, a step of lifting the battery cell 1 from the resin tank 32, curing the insulating resin 31, and forming an insulating insulating layer 30 on the bottom surface 23 of the battery cell 1; Can be included. Thereby, by impregnating the bottom surface of the battery cell with an uncured liquid insulating resin, the insulating layer can be formed in an intimate contact state by eliminating the air layer, and the thermal conductivity on this surface can be increased. It is superior in terms of heat dissipation. Moreover, since it can seal from the circumference | surroundings of an insulation cell to a bottom face, the drip-proof property and waterproof reliability can also be improved.

Furthermore, according to the method for manufacturing the power supply device according to the tenth aspect, the step of impregnating the liquid insulating resin 31 and the step of forming the insulating layer 30 are performed for each battery cell, and then the insulation is performed. The battery cells in which the layer 30 is formed can be stacked and fastened with the separator 2 interposed between the battery cells 1 adjacent to each other by fastening means. Thereby, after performing an insulation process separately with respect to a battery cell, these can be laminated | stacked and a battery block can be comprised.

Furthermore, according to the method for manufacturing the power supply device according to the eleventh aspect, the step of impregnating the liquid insulating resin 31 and the step of forming the insulating layer 30 include the step of attaching the plurality of battery cells 1 by the fastening means. 2 can be performed in a stacked state. Thereby, the insulation process can be collectively performed with respect to the battery block which laminated | stacked the battery cell, and an insulating layer can be coat | covered efficiently. Also, with this method, since the insulating layer can be impregnated in the gap between the separator adjacent to the battery cell, the advantage of improving the thermal coupling between the battery cell and the separator can be obtained.

Furthermore, according to the method of manufacturing the power supply device according to the twelfth aspect, the step of impregnating the liquid insulating resin 31 includes the step of impregnating the liquid insulating resin 31 impregnated into the bottom surface 23 of the battery cell 1. The battery block 50 laminated | stacked by the fastening means of the said battery cell 1 in the state can be mounted on the upper surface of the cooling plate 7. Thereby, a cooling plate and a battery block can be couple | bonded with an insulating resin in the close_contact | adherence state, and the air coupling | bonding can be ensured by eliminating an air layer.

Furthermore, according to the method of manufacturing the power supply device according to the thirteenth aspect, the battery block 50 can be placed on the upper surface of the cooling plate 7 in a separated state. Thus, the cooling plate and the battery block are separated from each other and kept in an insulating state, and can be fixed in close contact with the insulating resin, and a short circuit on the battery cell bottom surface by the cooling plate can be avoided.

Furthermore, according to the battery cell manufacturing method according to the fourteenth aspect, the outer shape composed of the top surface 24 and the bottom surface 23 and each pair of the main surface 21 and the side surface 22 is made thinner than the width. A battery cell manufacturing method comprising a rectangular outer can 12 and a cylindrical insulating coating film 20 that covers a main surface 21 and a side surface 22 of the outer can 12. The outer can 12 is inserted into the cylindrical covering film 20 that can be inserted into the casing, and the lower end edge of the covering film 20 is not projected from the bottom surface 23 of the outer can 12, and is positioned on the main surface 21 and the side surface 22. In this state, the step of heat shrinking the coating film 20 and the battery cell 1 filled with an uncured liquid insulating resin 31 from the bottom surface 23 to at least the bottom surface 23 of the battery cell 1. The whole surface and the main surface 21 line A step of impregnating the liquid insulating resin 31 with the covering film 20 so as to include the lower end, and the battery cell 1 is pulled up from the resin tank 32 to cure the insulating resin 31, Forming an insulating insulating layer 30 on the bottom surface 23 of the cell 1. Thereby, by impregnating the bottom surface of the battery cell with an uncured liquid insulating resin, the insulating layer can be formed in an intimate contact state by eliminating the air layer, and the thermal conductivity on this surface can be increased. It is superior in terms of heat dissipation. Moreover, since it can seal from the circumference | surroundings of an insulation cell to a bottom face, the drip-proof property and waterproof reliability can also be improved.

1 is a perspective view of a power supply device according to a first embodiment. It is a perspective view which shows the state which removed the upper case from FIG. It is a perspective view which shows the battery block of FIG. FIG. 4 is an exploded perspective view of the battery block of FIG. 3. It is a disassembled perspective view which shows the lamination | stacking state of the battery cells of FIG. It is a perspective view which shows the battery cell of FIG. It is a three-plane figure of the battery cell of FIG. It is sectional drawing of the insulating layer in the bottom face of the battery cell of FIG. It is a schematic diagram which shows the example which the lower end of a coating film protrudes from the bottom face of a battery cell. It is a disassembled perspective view of the battery cell of FIG. It is a front view which shows the state which coat | covered the coating film on the battery cell of FIG. It is a schematic diagram which shows the state which impregnates the bottom face of the battery cell of FIG. 11 in uncured liquid insulating resin. It is a schematic diagram which shows the state which impregnates a battery block in uncured liquid insulating resin. It is sectional drawing which shows the state which spaces apart a battery cell and a cooling plate through a spacer. It is sectional drawing which shows the state which clamps a battery cell with the separator which provided the rib. It is a schematic diagram which shows the cooling structure of the battery block which concerns on a modification. FIG. 17 is a partially enlarged vertical vertical sectional view of the battery block shown in FIG. 16. FIG. 17 is a vertical cross-sectional view of the battery block shown in FIG. 16. It is a block diagram which shows the example which mounts a battery system in the hybrid vehicle which drive | works with an engine and a motor. It is a block diagram which shows the example which mounts a battery system in the electric vehicle which drive | works only with a motor. It is a top view which shows the power supply device which laminated | stacked the battery cell. It is a side view of the power supply device of FIG. It is a perspective view of the battery cell of FIG. FIG. 24 is a trihedral view showing a state in which the battery cell of FIG. 23 is covered with a conventional coating film. It is a perspective view which shows a mode that the battery cell of FIG. 23 is coat | covered with the conventional coating film. It is a perspective view which shows a mode that a heat-shrink sheet | seat is heat-shrinked from the state of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a power supply device for embodying the technical idea of the present invention, a vehicle using the same, a battery cell, and a method for manufacturing the battery cell. The apparatus and the vehicle, battery cell, and battery cell manufacturing method using the same are not specified as follows. In addition, the member shown by the claim is not what specifies the member of embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in the embodiments are not intended to limit the scope of the present invention only to the description unless otherwise specified. It's just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing. In addition, the contents described in some examples and embodiments may be used in other examples and embodiments.
Example 1

1 to 20 show a power supply apparatus according to a first embodiment, a vehicle using the same, and a battery cell. In these drawings, FIG. 1 is a perspective view of the battery system 91, FIG. 2 is a perspective view showing a state where the upper case 72 is removed from FIG. 1, FIG. 3 is a perspective view showing the battery block 50 of FIG. 3 is an exploded perspective view of the battery block 50, FIG. 5 is an exploded perspective view showing a stacked state of the battery cells 1 of FIG. 4, FIG. 6 is a perspective view showing the battery cell 1 of FIG. 5, and FIG. FIG. 8 is a cross-sectional view of the insulating layer 30 on the bottom surface 23 of the battery cell 1 in FIG. 6, and FIG. 9 is a schematic diagram illustrating an example in which the lower end of the coating film protrudes from the bottom surface 23 of the battery cell 1. 10 is an exploded perspective view of the battery cell 1 of FIG. 6, FIG. 11 is a front view showing a state in which the battery cell 1 of FIG. 10 is covered with a coating film, FIG. 12 shows an uncured liquid insulating resin 31, and FIG. FIG. 13 is a schematic diagram showing a state in which the bottom surface 23 of the battery cell 1 is impregnated. FIG. 14 is a cross-sectional view showing a state in which the battery cell 1 and the cooling plate 7 are physically separated with a spacer 40 interposed therebetween, FIG. FIG. 16 is a cross-sectional view showing a state in which the battery cell 1 is sandwiched between the separators 2 provided with ribs 41, FIG. 16 is a schematic view showing a cooling structure of the battery block 50 according to a modification, and FIG. 17 is a battery block 50 shown in FIG. 18 is a partially enlarged vertical longitudinal sectional view, FIG. 18 is a vertical transverse sectional view of the battery block 50 shown in FIG. 16, and FIG. 19 is a block diagram showing an example in which a battery system is mounted on a hybrid vehicle running with an engine and a motor. FIG. 1 is a block diagram showing an example in which a battery system is mounted on an electric vehicle that runs only by a motor.

As shown in FIGS. 1 and 2, the external appearance of the battery system 91 is obtained by dividing a box-shaped outer case 70 into two and housing a plurality of battery blocks 50 therein. The exterior case 70 includes a lower case 71, an upper case 72, and end plates 73 connected to both ends of the lower case 71 and the upper case 72. The upper case 72 and the lower case 71 have a flange portion 74 protruding outward, and the flange portion 74 is fixed with a bolt and a nut. In the exterior case 70 of FIGS. 1 and 2, the flange portion 74 is disposed on the side surface of the exterior case 70. In the example of FIG. 2, a total of four battery blocks 50 are stored in the lower case 71, two in the longitudinal direction and two in the horizontal direction. Each battery block 50 is fixed to the lower case 71 with a set screw or the like, and fixed to a fixed position inside the outer case 70. The end surface plate 73 is connected to both ends of the lower case 71 and the upper case 72 and closes both ends of the exterior case 70.
(Battery block 50)

As shown in FIG. 3, each battery block 50 has a substantially box-like appearance, and a battery stack 10 in which a large number of battery cells 1 are stacked is sandwiched by end plates 4 from both end faces via bind bars 11. Yes. As shown in the exploded perspective view of FIG. 4, the battery stack 10 is configured by stacking a plurality of prismatic battery cells 1 via separators 2. In the example of the battery block 50 in FIG. 4, 18 rectangular battery cells 1 are stacked. The bind bar 11 functions as a fastening means for fastening the battery cell 1. In this example, both ends of the strip-shaped metal plate are bent into bent pieces, and the whole is formed in a U shape. Further, the end plate 4 is provided with a recess at a position for receiving the bent piece of the bind bar 11. By providing a screw hole in the bent piece and the end plate 4, the bind bar 11 is screwed and fixed to the end plate 4.
(Battery cell 1)

As shown in FIG. 5 and FIG. 6, the battery cell 1 is configured by an outer can 12 having an outer shape with a rectangular shape whose thickness is thinner than a width, and closes the top surface 24 of the outer can, that is, the outer can 12. Positive and negative electrode terminals 13 are provided on the sealing plate. The electrode terminals 13 are electrically connected via a bus bar 17 shown in FIG. The outer can of the battery cell can be made of an insulating material such as plastic. In this case, since it is not necessary to insulate the outer can when the battery cells are stacked, the separator can be made of metal.
(Separator 2)

The battery block 50 has a separator 2 sandwiched between stacked battery cells 1. The battery block 50 can be laminated with the outer can 12 of the battery cell 1 made of metal and insulated by the plastic separator 2. The separator 2 has a shape that can be fitted to the battery cell 1 on both sides, and can be stacked while preventing the positional deviation of the adjacent battery cells 1. The battery block can also be fixed in a laminated state without sandwiching a separator by using an outer can of the battery cell as an insulating material such as plastic.

As shown in FIG. 5, the separator 2 is provided with a cooling gap 53 that allows a cooling gas such as air to pass between the battery cell 1 and the battery cell 1 in order to cool the battery cell 1. Thereby, the battery block 50 has laminated | stacked the several battery cell 1 in the state in which the cooling gap 53 is made. As a cooling mechanism for cooling the battery cells 1 of the battery block 50 by forcibly blowing cooling gas, a forced blowing mechanism 9B is provided as shown in FIG. As shown in FIG. 4, the battery block 50 has a separator 2 sandwiched between stacked battery cells 1. As shown in FIG. 5, the separator 2 has a shape in which a cooling gap 53 is formed between the separator 2 and the battery cell 1. Furthermore, the separator 2 of the figure has connected the battery cell 1 with the fitting structure on both surfaces. Through the separator 2 connected to the battery cell 1 with a fitting structure, the adjacent battery cells 1 are stacked while being prevented from being displaced.
(Battery cell 1)

The battery cell 1 is a prismatic battery of a lithium ion secondary battery. However, the battery cell may be a secondary battery such as a nickel metal hydride battery or a nickel cadmium battery. The battery cell 1 shown in FIG. 6 made of a square battery is a quadrilateral having a predetermined thickness, and has positive and negative electrode terminals 13 protruding from both ends of the top surface 24, and a safety valve at the center of the top surface 24. The opening is provided. The battery cells 1 to be stacked are connected in series by connecting adjacent positive and negative electrode terminals 13 with a bus bar 17. A battery system in which adjacent battery cells 1 are connected in series can increase the output voltage and increase the output. However, the battery system can also connect adjacent battery cells in parallel.

The surfaces of the battery cell 1 other than the top surface 24 are insulated. Specifically, the surface excluding the top surface 24 and the bottom surface 23 of the battery cell 1 is covered with the coating film 20. The bottom surface 23 is insulated by an insulating layer 30 described later. The top surface 24 is not insulated because the electrode terminals 13 need to be exposed for electrical connection, while the other surfaces are insulated to avoid unintended short circuits. In the configuration in which the battery cells are provided with an insulating property by covering with such an insulating material, it is necessary to pay attention so that the height positions of the battery cells are aligned when the battery cells are stacked. That is, when the battery cells are stacked to form a battery stack, the electrode terminals 13 of the adjacent battery cells are fastened by the bus bar 17, and at this time, the surface of the battery cell is insulated only by the conventional shrink tube. In the method, the height direction positions of the electrode terminals of the adjacent battery cells are shifted due to the step formed on the bottom surface of the battery cell. As a result, a contact failure between the bus bar and the electrode terminal occurs, or an extra load is applied to the electrode terminal. In order to solve this problem, in this embodiment, the use of the insulating layer 30 in addition to the covering film avoids a situation where a step is formed on the bottom surface 23 of the battery cell 1. This will be described below.
(Coating film 20)

The main surface 21 of the battery cell 1 is covered with a covering film 20 as shown in FIGS. 6, 7, and 8. The covering film 20 is covered as a heat shrinkable tube by heat shrinking the outer surface of the battery cell 1. For such a covering film 20, a resin such as PET preferably having excellent insulating properties and stability can be used. In particular, a shrink tube made of PET resin is inexpensive and preferable as a heat shrinkable tube.

As shown in the cross-sectional view of FIG. 8, the covering film 20 is preferably the same length as the side surface 22 of the battery cell 1 or the length thereof so as not to protrude from the bottom surface 23 of the battery cell 1 in the vicinity of the bottom surface 23 of the battery cell 1. It is formed to be shorter. By doing in this way, the situation where the coating film 20 protrudes to the bottom face 23 side of the battery cell 1 can be avoided. As shown in FIG. 9, when the covering film 20 is formed long and protrudes by t from the bottom surface 23 of the battery cell 1, the bottom surface of the battery cell 1 is covered with the insulating layer 30 covering the battery cell bottom surface 23. As a result, the bottom surface 23 of the battery cell 1 does not become flat, and irregularities are partially formed. Since such unevenness may cause individual differences for each battery cell, when stacking battery cells, the height or protruding amount of the battery cells cannot be kept constant, and the bottom surface and the ceiling of the battery cell cannot be maintained. When the surface of the battery cell is not aligned, the height of the electrode terminal is not aligned on the top surface of the battery cell, and when the adjacent electrode terminals are connected by the bus bar, the fixed state with the bus bar varies from battery cell to battery cell, resulting in high contact resistance. Become. Further, when connecting to the cooling plate on the bottom surface of the battery cell (FIG. 16 described later), the contact area between the cooling plate and the battery cell bottom surface is different, the cooling capacity varies, and the performance between the battery cells is deteriorated. This is not preferable because individual differences occur.

Therefore, in order to avoid the occurrence of such unevenness, the covering film 20 has the bottom surface 23 of the battery cell 1 substantially the same height so as not to protrude from the bottom surface 23 of the battery cell 1, or the covering film 20 or the battery Considering the manufacturing tolerance of the cell 1, the lower end of the covering film 20 is set to be slightly shorter than the bottom surface 23 of the battery cell 1 as shown in FIG. By doing in this way, protrusion of the coating film 20 from the battery cell bottom face 23 can be avoided, and it leads to manufacture of a stable battery cell.

Note that the fact that the coating film does not protrude from the bottom surface side of the battery cell does not mean that the length of the coating film is necessarily shorter than the height of the battery cell. That is, it is sufficient that the coating film does not protrude from the bottom surface side of the battery cell, and conversely, the coating film slightly protruding on the top surface side of the battery cell is allowed as long as the electrical connection of the electrode terminals is not hindered.

That is, on the top surface 24 side, when the battery cells 1 are stacked to form a battery stack, variation in the height position of the electrode terminals 13 between the adjacent battery cells 1 can be suppressed, and when connecting using the bus bar However, the height difference can be reduced, the contact state can be made uniform and the bus bar can be fastened without any trouble, and the reliability of the electrical connection can be improved.

On the other hand, in order to avoid reaching the bottom surface of the battery cell, in other words, when the covering film is intentionally shortened at the lower end and the main surface of the battery cell is exposed near the bottom surface, this portion is not intended unless it is covered. Conduction occurs. Therefore, the insulating layer 30 covering the bottom surface 23 of the battery cell 1 is continuously extended from the bottom surface 23 side to cover such an exposed portion. As a result, a portion where the covering film 20 and the insulating layer 30 overlap is generated along the periphery of the battery cell 1. In the three views of FIG. 7, the overlapping portion is indicated by OW.

To coat the outer can with this covering film, the outer can 12 is inserted into a cylindrical covering film 20 into which the outer can 12 can be inserted, as shown in FIG. Here, the lower end of the coating film 20 is aligned with the main surface 21 and the side surface 22 of the battery cell 1 at a position that does not protrude from the lower end edge, and is thermally welded. As a result, as shown in FIG. 11, the covering film can be fixed in a state where the main surface 21 and the side surface 22 of the outer can are covered.
(Insulating layer 30)

The insulating layer 30 is made of a resin having an insulating property, and a resin having an excellent insulating property such as silicone, urethane, or epoxy can be suitably used. Further, a liquid resin is used in an uncured state. By making such a liquid, as shown in FIG. 12, the bottom surface 23 of the battery cell 1 shown in FIG. 11 is impregnated into the uncured liquid insulating resin 31 filled in the resin tank 32. The insulating layer 30 is formed by curing the resin, and the bottom surface 23 of the battery cell 1 not covered with the covering film is covered and insulated by the insulating layer 30. According to this method, the liquid insulating resin 31 before curing spreads over the surface of the battery cell 1 and also enters and fills in the minute gaps between the battery cell 1 and the coating film. Without being formed, an insulating sealing structure is configured.

Also, with this method, it is easy to form the insulating layer 30 with a uniform thickness. In particular, by forming the insulating layer 30 thin, it is possible to avoid a conspicuous step formed by the edge of the insulating layer on the main surface 21 of the battery cell 1, and the battery cell main surface 21 can be maintained flat. The thickness of the insulating layer 30 is preferably 0.01 mm to 3 mm, more preferably 0.05 mm to 0.2 mm. Further, since not only the main surface 21 of the battery cell 1 but also the bottom surface 23 can be substantially flat, it is convenient to form a thermal coupling by bringing this surface into contact with the heat radiating plate. Further, since the bottom surface 23 of the battery cell 1 is insulated, even if it is brought into direct contact with the metal heat radiating plate, it is not short-circuited between adjacent battery cells. In addition, since the bottom surface 23 can be completely covered, the waterproof property can be exhibited against dew condensation and water intrusion, and the battery cell can be protected from water droplets.

Impregnation can be easily performed by dipping. Here, it is sufficient to immerse the battery cell until the liquid insulating resin 31 is positioned higher than the lower end of the coating film. In particular, by reducing the thickness of the insulating layer 30, there is no noticeable level difference, and no precise control is required for the region OW where the covering film and the insulating layer 30 overlap, and impregnation workability is improved. Also excellent.

The battery cell 1 having the bottom surface 23 covered with the insulating layer 30 in this way is fastened by fastening means with the separator 2 interposed therebetween, and constitutes a battery block 50. In the example of FIG. 12, the example in which one battery cell 1 is individually impregnated in the resin tank 32 and the insulating layer 30 is provided has been described. However, the present invention is not limited to this example, and for example, battery cells covered with a coating film are stacked. In this state, the resin tank 32 can be impregnated as shown in FIG. This method is excellent in dipping workability because it can be impregnated all at once. Further, by dipping the bottom surface 23 while the battery cell 1 is held between the separators 2, the liquid insulating resin 31 is filled not only in the bottom surface 23 of the battery cell 1 but also in the gap between the battery cell 1 and the separator 2. Thus, formation of an air layer between the battery cell 1 and the separator 2 is also eliminated, and an advantage that is advantageous in heat dissipation via the separator 2 can be obtained. Further, after impregnating and dipping the battery block 50 in a lump and before the liquid insulating resin 31 is cured, the battery block 50 is disposed on the cooling plate 7 to be described later. 50 can be fixed in close contact with the cooling plate 7. Since no gap is formed between the battery block 50 and the cooling plate 7 and air bubbles are prevented from entering, the battery block 50 can be cooled more efficiently by the cooling plate.

As described above, the main surface 21 and the side surface 22 of the battery cell 1 are mainly insulated by the covering film, while the bottom surface 23 of the battery cell 1 is insulated by applying the insulating layer 30. As described above, by properly using the insulating configuration, it is possible to configure cell insulation that can achieve both the cooling performance and the strength of the insulating layer 30. That is, since the main surface 21 of the battery cell 1 is fastened by the fastening means in a state where a large number of battery cells 1 are stacked via the separator 2, a high pressure is applied. For this reason, the intensity | strength which can maintain insulation even if always exposed to a high pressing force is calculated | required. A coated film such as a shrink tube has high strength and is convenient for such an application. On the other hand, on the bottom surface of the battery cell, not only insulation but also maintenance of waterproofness is important. In particular, water entering from the outside and dew condensation generated inside accumulate at the bottom inside the case, so it can be said that the bottom surface of the battery cell is easily flooded. Therefore, it can be said that the insulating layer 30 formed by impregnating the liquid insulating resin 31 in which a slight gap or gap is filled so as to reliably prevent the intrusion of moisture is preferable from the viewpoint of such waterproofness. In this way, the main surface 21 of the battery cell 1 that requires strength and thinness is insulated with a coating film, while the bottom surface 23 of the battery cell 1 is formed with an insulating layer 30 by dipping, thereby providing cooling performance and insulation. It is possible to realize an insulating structure that can achieve both layer strength and excellent reliability.

As described above, the bottom surface 23 of the battery cell 1 covered with the insulating layer 30 is not provided with irregularities, and is maintained flat. In this way, when stacking a plurality of battery cells 1, it becomes easy to match the bottom surface 23 so as to be substantially the same surface. As a result, the electrode terminals 13 are also on the same surface on the top surface of the battery stack 10. As a result, the connection by the bus bar 17 and the like can be performed stably, leading to an improvement in reliability.

In addition, as shown in the modification of FIG. 16, in the cooling method in which the bottom surface 23 of the battery cell 1 is brought into contact with the cooling plate 7 to cool, the contact surface between the battery cell 1 and the cooling plate 7 is a flat surface. The heat coupling can be ensured and the cooling capacity can be demonstrated. In particular, the cover film is not protruded toward the bottom surface of the battery cell, and the bottom surface 23 coated with the insulating layer 30 is made to be a substantially flat surface along the bottom surface 23 of the outer can so that the connection with the cooling plate 7 for each battery cell is achieved. There are also advantages that individual differences and variations in state can be reduced, and variations in cooling capacity between battery cells can be suppressed. Further, by not providing an extra unevenness on the main surface 21 side of the battery cell 1, it becomes possible to stably stack the battery cells, and there is also an advantage that the fastening by the bind bar can be surely performed.
(Spacer 40)

Further, the battery cell bottom surface 23 covered with the insulating layer 30 is directly connected to the cooling plate 7, and the battery cell 1 and the cooling plate 7 are physically separated by interposing a spacer 40 as shown in FIG. It is also possible to insulate between the two. The spacer 40 is made of an insulating member. In this configuration, since the insulation between the battery cell 1 and the cooling plate 7 is exhibited by the spacer 40 in addition to the insulating layer 30, double protection is achieved.

Also, the spacer can be formed as a separate member or integrally with the separator. For example, in the example shown in FIG. 15, a rib 41 bent at a lower end of the separator 2 so as to partially cover the bottom surface 23 of the battery cell 1 is provided as the spacer 40. The battery cell 1 whose bottom surface 23 is covered with the rib 41 is in a state of being lifted from the floor surface while being sandwiched between the separators 2. Even in this configuration, the battery cell 1 can be physically separated from the cooling plate 7 to reliably maintain insulation.

Further, when such a spacer 40 is used, the method of dipping the battery stack is particularly advantageous as shown in FIG. 12 described above. That is, by applying the uncured liquid insulating resin 31, the resin also enters and fills the gaps between the spacer 40, the cooling plate 7, and the battery cell 1. Thermal conductivity is improved. In this case, in addition to dipping the battery stack in the resin tank 32, the insulating layer can be formed by pouring the liquid insulating resin 31 in a state where the battery stack is placed on the cooling plate.

As described above, the reliability of the battery stack in which the battery cells are stacked by individually configuring the covering film that covers the main surface 21 and the side surface 22 of the battery cell 1 and the insulating layer 30 that covers the bottom surface 23. Can be increased.
(Modification)

Moreover, in the example of FIG. 1 etc. which were demonstrated above, although the air-cooling type which forcedly ventilates cooling air with a fan and cooled the battery cell 1 was employ | adopted, it is not restricted to this structure, It cools directly using a refrigerant | coolant etc. It is good also as a structure which employ | adopts a cooling system. Such an example will be described as a modification with reference to FIGS.

The power supply device that constitutes the battery system 92 shown in FIG. 16 is arranged in a thermally coupled state to the battery stack 10 in which the battery cells 1 composed of a plurality of prismatic batteries are stacked, and to the battery cells 1 that constitute the battery stack 10. And a cooling mechanism 9 for cooling the cooling plate 7. The cooling mechanism 9 can effectively cool the battery stack 10 directly by bringing the battery stack 10 into contact with the cooling plate 7. Further, not only the battery stack, but also, for example, each member disposed on the end face of the battery stack 10 can be cooled together, which is excellent in terms of reliability.
(Cooling plate 7)

The cooling plate 7 is a heat radiating body for conducting heat of the battery cell 1 to dissipate it to the outside, and in the example shown in the figure, a refrigerant pipe is provided. As shown in the cross-sectional view of FIG. 17, the cooling plate 7 has a closed chamber as an inside, and as a heat exchanger in the closed chamber, a coolant pipe 26 made of copper, aluminum, or the like that circulates a liquefied coolant that is a coolant. Built-in cooling pipe. The cooling pipe is fixed so as to be in close contact with the upper surface plate of the cooling plate 7 to cool the upper surface plate, and a heat insulating material is disposed between the cooling plate and the bottom plate to insulate the space from the bottom plate. Further, the cooling plate 7 can be composed of only a metal plate in addition to the cooling function by the refrigerant. For example, it is made into the shape excellent in heat dissipation and heat transfer property, such as a metal body provided with a radiation fin. Or you may utilize not only metal but the heat-transfer sheet | seat which has insulation.

The cooling plate 7 constitutes a battery cooling means for cooling the battery stack 10 placed on the upper surface. In this example, as shown in the cross-sectional views of FIGS. 17 and 18, a refrigerant pipe 26 for circulating the refrigerant is provided inside the cooling plate 7. The coolant is supplied from the cooling mechanism 9 shown in FIG. 16 to the refrigerant pipe 26 to cool the cooling plate 7. The cooling plate 7 can cool the cooling plate 7 more efficiently by using the cooling liquid supplied from the cooling mechanism 9 as a refrigerant that cools the cooling plate 7 with heat of vaporization that evaporates inside the refrigerant pipe 26.

The cooling plate 7 is fixed in a thermally coupled state to the bottom surface 23 which is the outer peripheral surface of each battery cell 1 constituting the battery block 200 in order to cool the battery cell 1. In a battery system in which adjacent battery cells are connected in series, there is a potential difference between adjacent battery cells. Therefore, if a battery cell composed of a metal outer can is electrically connected to the cooling plate as it is, a short circuit occurs and a large short current flows. On the other hand, as described above, the battery cell 1 in which the bottom surface 23 of the outer can is covered with the insulating layer 30 can avoid such a short circuit and can be thermally coupled to the cooling plate 7 in an insulated state. The insulating layer 30 is preferably made of an insulating member having excellent thermal conductivity so that the insulating layer 30 can be in a thermally coupled state while being insulated from the cooling plate 7. A polyimide tape or the like is suitable as a material for obtaining such characteristics as described above. Further, a heat conductive paste such as silicon oil may be applied between the insulating layer 30 and the cooling plate 7 so as to conduct heat more efficiently.

Further, the cooling plate 7 also functions as a soaking means for equalizing the temperatures of the plurality of battery cells 1. That is, the heat energy absorbed by the cooling plate 7 from the battery cell 1 is adjusted to efficiently cool the battery cell whose temperature is increased, for example, the battery cell in the central portion, and the battery where the temperature is decreased, such as the battery at both ends. Reduce the temperature difference between the battery cells by reducing the cooling of the cells. Thereby, the temperature unevenness of the battery cells can be reduced, and a situation in which deterioration of some of the battery cells proceeds and overcharge and overdischarge can be avoided.

In the example of FIG. 16, an example in which the cooling plate 7 is disposed on the bottom surface 23 of the battery block 200 is shown, but the configuration is not limited to this. For example, the cooling plate can be disposed on the side surface of the battery cell.
(Vehicle using power supply)

Next, a vehicle equipped with a power supply device using the above battery cells will be described with reference to FIGS. FIG. 19 shows an example of a hybrid vehicle HV that is equipped with a battery system for a vehicle and that travels by both an engine and a motor. The hybrid vehicle shown in this figure includes an engine 96 and a running motor 93 for running the vehicle,

battery systems

91 and 92 for supplying electric power to the motor 93, and a generator 94 for charging the batteries of the

battery systems

91 and 92. I have. The

battery systems

91 and 92 are connected to a motor 93 and a generator 94 via a DC / AC inverter 95. The hybrid vehicle runs on both the motor 93 and the engine 96 while charging and discharging the batteries of the

battery systems

91 and 92. The motor 93 is driven to drive the vehicle when the engine efficiency is low, for example, during acceleration or low-speed driving. The motor 93 is driven by power supplied from the

battery systems

91 and 92. The generator 94 is driven by the engine 96 or is driven by regenerative braking when the vehicle is braked, and charges the batteries of the

battery systems

91 and 92.

Further, FIG. 20 shows an example of an electric vehicle EV which is a vehicle equipped with a battery system for vehicles and runs only by a motor. The electric vehicle shown in this figure includes a traveling motor 93 for traveling the vehicle,

battery systems

91 and 92. I have. The

battery systems

91 and 92 are connected to a motor 93 and a generator 94 via a DC / AC inverter 95. The motor 93 is driven by power supplied from the

battery systems

91 and 92. The generator 94 is driven by energy used when regenerative braking of the vehicle, and charges the batteries of the

battery systems

91 and 92.

A power supply apparatus according to the present invention, a vehicle using the same, a battery cell, and a battery cell manufacturing method include a plug-in hybrid electric vehicle, a hybrid electric vehicle, an electric vehicle, and the like that can switch between an EV traveling mode and an HEV traveling mode. It can be suitably used as a power supply device.

DESCRIPTION OF

SYMBOLS

1, 1X ... Battery cell 2 ... Separator 4 ... End plate 7 ... Cooling plate 9 ... Cooling mechanism 9B ... Forced ventilation mechanism 10 ... Battery laminated body 11 ... Bind bar 12 ... Exterior can 13 ... Electrode terminal 17 ... Bus bar 20 ... Covering film 20X ... heat shrink sheet 21 ... main surface 22 ... side surface 23 ... bottom surface 24 ... top surface 26 ... refrigerant pipe 30 ... insulating layer 31 ... insulating resin 32 ... resin tank 40 ... spacer 41 ... rib 50 ... battery block 53 ... cooling gap 70 ... Exterior case 71 ... Lower case 72 ... Upper case 73 ... End face plate 74 ...

Bridges

91, 92 ... Battery system 93 ... Motor 94 ... Generator 95 ... Inverter 96 ... Engine 200 ... Battery block HV, EV ... Vehicle OW ... Overlapping part t ... Projection amount

Claims

A plurality of battery cells (1) whose outer shape is a square with a thickness smaller than the width,
A separator (2) for insulating between the battery cells (1) by interposing on the surface where the plurality of battery cells (1) are laminated,
Fastening means for stacking and fastening the plurality of battery cells (1) with the separator (2) interposed therebetween,
A power supply device comprising:
Each of the battery cells (1) is
A top surface (24), a bottom surface (23), and a rectangular outer can (12) composed of a pair of main surfaces (21) and side surfaces (22);
A cylindrical insulating covering film (20) covering the main surface (21) and the side surface (22) of the outer can (12);
An insulating insulating layer (30) covering the bottom surface (23) of the outer can (12);
With
The insulating layer (30) covers the entire bottom surface (23) of the outer can (12) in a close contact state, and extends from the bottom surface (23) to the main surface (21) and the side surface (22), and at least It is coated so as to overlap a part of the lower edge of the covering film,
The power supply device, wherein the bottom surfaces (23) of the plurality of battery cells (1) are fastened in a stacked state by the fastening means in a posture in which they are arranged on substantially the same plane.
The power supply device according to claim 1, further comprising:
A power supply apparatus comprising: a cooling plate (7) provided with a refrigerant pipe (26) arranged in a thermally coupled state with a bottom surface (23) of the outer can (12).
The power supply device according to claim 2,
The cooling plate (7) and the outer can (12) are made of metal,
A power supply device comprising an insulating spacer (40) for separating the cooling plate (7) and the bottom surface (23) of the outer can (12).
The power supply device according to claim 3,
In the state where the separator (2) is in contact with the battery cell (1), a rib (41) is provided to partially cover the bottom surface (23) of the battery cell (1).
The power supply device according to claim 1, wherein the rib is interposed between the bottom surface (23) of the battery cell (1) and the cooling plate (7) so as to be separated from each other.
The power supply device according to any one of claims 1 to 4,
The power supply apparatus according to claim 1, wherein a lower end edge of the covering film (20) is not projected from the bottom surface (23) of the outer can (12) but is positioned on the main surface (21) and the side surface (22).
The power supply device according to any one of claims 1 to 5,
The power supply apparatus, wherein the covering film (20) is a heat shrinkable tube.
A vehicle comprising the power supply device according to claim 1.
An outer can (12) having a top surface (24), a bottom surface (23), and a pair of main surfaces (21) and side surfaces (22), the outer shape being a rectangular shape with a thickness smaller than the width;
A cylindrical insulating covering film (20) covering the main surface (21) and the side surface (22) of the outer can (12);
An insulating insulating layer (30) covering the bottom surface (23) of the outer can (12);
With
The lower end edge of the covering film (20) does not protrude from the bottom surface (23) of the outer can (12), and is positioned on the main surface (21) and the side surface (22),
The insulating layer (30) covers the entire bottom surface (23) of the outer can (12) in a close contact state, and extends from the bottom surface (23) to the main surface (21) and the side surface (22), and at least A battery cell, wherein the battery cell is coated so as to overlap a part of a lower end edge of the covering film.
A plurality of battery cells (1) in which the outer shape of the outer can is a rectangular shape whose thickness is smaller than the width;
A separator (2) for insulating between the battery cells (1) by interposing on the surface where the plurality of battery cells (1) are laminated,
Fastening means for stacking and fastening the plurality of battery cells (1) with the separator (2) interposed therebetween,
A method of manufacturing a power supply device comprising:
The cylindrical covering film (20) into which the outer can (12) composed of the top surface (24) and the bottom surface (23), and each pair of main surfaces (21) and side surfaces (22) can be inserted, The outer can (12) is inserted, and the lower end edge of the covering film (20) is not projected from the bottom surface (23) of the outer can (12), and is positioned on the main surface (21) and the side surface (22). In a state where the coating film (20) is thermally shrunk,
The battery cell (1) is filled in the resin tank (32) filled with uncured liquid insulating resin (31) from the bottom surface (23), at least the entire bottom surface (23) of the battery cell (1), and the main body. Impregnating the liquid insulating resin (31) to include the lower end of the surface (21) and the side surface (22), and including the lower end;
The battery cell (1) is pulled up from the resin tank (32), the insulating resin (31) is cured, and an insulating insulating layer (30) is formed on the bottom surface (23) of the battery cell (1). Process,
The manufacturing method of the battery cell characterized by including.
It is a manufacturing method of the power supply device according to claim 9,
The step of impregnating the liquid insulating resin (31) and the step of forming the insulating layer (30) are performed for each battery cell (1), and then the battery cell in which the insulating layer (30) is formed ( 1) A method of manufacturing a power supply device, comprising a step of laminating and fastening each other with battery cells (1) adjacent to each other by fastening means while interposing the separator (2).
It is a manufacturing method of the power supply device according to claim 9,
The step of impregnating the liquid insulating resin (31) and the step of forming the insulating layer (30) are performed in a state where the plurality of battery cells (1) are laminated with the separator (2) interposed by fastening means. A method of manufacturing a power supply device, which is performed.
It is a manufacturing method of the power supply device according to any one of claims 9 to 11,
In the step of impregnating the liquid insulating resin (31), the liquid insulating resin (31) impregnated on the bottom surface (23) of the battery cell (1) is in an uncured state, and the battery cell (1) A method of manufacturing a power supply device, comprising a step of placing a battery block (50) laminated by a fastening means on an upper surface of a cooling plate (7).
It is a manufacturing method of the power supply device according to claim 12,
A method of manufacturing a power supply device, wherein the battery block (50) is placed on the upper surface of the cooling plate (7) in a separated state.
An outer can (12) having a top surface (24), a bottom surface (23), and a pair of main surfaces (21) and side surfaces (22), the outer shape being a rectangular shape with a thickness smaller than the width;
A cylindrical insulating covering film (20) covering the main surface (21) and the side surface (22) of the outer can (12);
A method for producing a battery cell comprising:
Inserting the outer can (12) into the cylindrical covering film (20) into which the outer can (12) can be inserted, the lower end edge of the covering film (20), the outer can (12) Without projecting from the bottom surface (23), the step of heat shrinking the covering film (20) in a state of being located on the main surface (21) and the side surface (22),
The battery cell (1) is filled in the resin tank (32) filled with uncured liquid insulating resin (31) from the bottom surface (23), at least the entire bottom surface (23) of the battery cell (1), and the main body. Impregnating the liquid insulating resin (31) to include the lower end of the surface (21) and the side surface (22), and including the lower end;
The battery cell (1) is pulled up from the resin tank (32), the insulating resin (31) is cured, and an insulating insulating layer (30) is formed on the bottom surface (23) of the battery cell (1). Process,
The manufacturing method of the battery cell characterized by including.