JP5479947B2 - Battery case - Google Patents

Description

  The present invention relates to a case constituting a battery such as a lithium ion battery, and more particularly to a battery case used in a stacked state.

  Conventionally, a battery in which a plurality of flat unit cells are connected in series or in parallel to form an assembled battery or a module and the required power is obtained in a stacked state is known. Documents 1 to 4 are described. Among these, the assembled battery described in Patent Document 1 is configured by laminating an intermediate plate having a plurality of flat plate type single cells as separators, and the assembled battery described in Patent Document 2 is A flat unit cell is laminated with a plate-shaped heat sink interposed therebetween, and these are united together. On the other hand, the assembled battery described in Patent Document 3 and Patent Document 4 is housed in the case, and a cooling medium such as air is circulated through the case so as to prevent temperature rise. It is configured.

JP 2006-66322 A Japanese Patent No. 3731595 JP 2007-59088 A JP 2006-156090 A

  The unit cells constituting each of the above-mentioned assembled batteries generate heat when discharged or charged, and in extreme cases, there is a possibility of thermal runaway. Become. Therefore, as described in each of the above patent documents, a configuration for cooling is adopted, and in the case where the unit cell is configured to be accommodated in the case, Patent Document 3 and Patent As described in Document 4, each cell is directly cooled by providing an inlet and an outlet in the case, supplying a cooling fluid such as air into the case from the outside, and discharging it. It is configured to do. This is a configuration that accompanies a large number of single cells accommodated in one case. Therefore, in addition to the necessity to provide an inflow port and an outflow port in the case, a cooling fluid is provided inside the case. Therefore, there is a possibility that the structure of the assembled battery or the battery module becomes complicated and the productivity is deteriorated.

  In addition, the cases described in Patent Document 3 and Patent Document 4 described above are the most common rectangular parallelepiped shapes, and have a structure that takes into account the manufacturability and assemblability when stacked. However, there is room for developing a case excellent in assemblability and manufacturability without impairing cooling performance and strength as a case for an assembled battery used in a stacked manner.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a battery case excellent in assemblability and manufacturability without impairing cooling performance and strength.

In order to achieve the above object, the invention of claim 1 is formed as a thin hollow body so as to accommodate a battery unit, and is used by electrically connecting the battery units to each other in a stacked state. In the battery case, the support portions interposed between the mutually facing surfaces so that a gap through which the cooling fluid flows is formed between the surfaces facing each other in the stacking direction in the stacked state. And / or an opening that is formed in at least one of the peripheral portions of the surface and that communicates the gap with the outside is formed in at least one of the surfaces facing each other . A peripheral wall portion that is formed on the peripheral portion of one of the surfaces facing each other so as to protrude toward the other surface side, and an inner surface of the peripheral wall portion and / or a portion on the front end side of the peripheral wall portion An inclined receding surface that is deformed so as to be separated from the peripheral wall portion is formed on the peripheral portion of the other surface. The opening portion is a portion where the inclined receding surface and the peripheral wall portion are separated from each other .

According to a second aspect of the present invention, in the first aspect of the invention, at least one of the surfaces facing each other is fitted with any part of the constituent members of the battery unit. The battery case is characterized in that a relative position between the surface and the battery unit is determined and a through hole is formed to be fixed to each other.

According to a third aspect of the present invention, in the second aspect of the present invention, the constituent members of the battery unit are arranged around the power contact hole in the battery unit, and the power contact hole and the through hole coincide with each other. In this state, the battery case includes an insulating member fitted and / or connected to the through hole .

  According to the present invention, when the assembled battery configured to accommodate the battery unit is stacked inside the case, the support portion provided on one of the facing surfaces of the cases adjacent to each other is provided between the facing surfaces. Since the gap is secured to the outside and communicated to the outside through the opening, a passage through which the cooling fluid flows can be formed between the stacked assembled batteries. Therefore, according to the present invention, the assembled battery can be air-cooled, for example, to avoid temperature rise or thermal runaway. In addition, if the support portion is configured by a leg portion that contacts the inner surface of the peripheral wall portion and / or the tip side portion of the peripheral wall portion in a stacked state, the relative positions of the stacked cases can be determined by the leg portions. In addition, since the relative parallel movement of each can be restricted, the assemblability for stacking the assembled batteries can be improved. This is because a stepped portion is formed on one peripheral portion of the surfaces facing each other in the laminated state, and the inner surface of the peripheral wall portion and / or the tip side portion of the peripheral wall portion formed on the peripheral portion of the other surface is formed on the stepped portion. When configured to be engaged, the relative positions of the stacked cases can be determined by continuously contacting with the stepped portions, and the relative translation of each can be further restricted. When the inclined receding surface is formed as the opening, the strength of the case can be further improved by forming the reinforcing bead portion together therewith. And the assembly property of the battery unit of each assembled battery and a case can be improved by providing the through-hole which fits the structural member of an electric unit. Moreover, the assembly property which laminates each assembled battery can be improved more by providing the insulating member which is arrange | positioned around the contact hole for electric power, and is fitted to the case and / or connected.

It is a perspective view which shows an example of this invention. It is the bottom view. It is a partial side view which shows one of the leg parts. It is a fragmentary sectional view which shows the winding fastening part of the cover part and a main-body part. It is a fragmentary sectional view which shows typically the fitting state of the insulating member with respect to a through-hole. It is a fragmentary sectional view which shows the contact state of the leg part and cover part in the laminated state. It is a fragmentary sectional view showing an example of an opening formed between cases supported by a leg. It is a bottom view which shows the other example of this invention. It is a fragmentary sectional view which shows the shape of the step part. It is a fragmentary sectional view which shows the engagement state of the step part and a surrounding wall part. It is a fragmentary sectional view showing an example of the shape of the inclined receding surface. It is a fragmentary sectional view showing the state where the inclined receding surface is separated from the peripheral wall portion in the laminated state.

  The present invention will be described with reference to specific examples shown in the drawings. A battery case 1 according to the present invention is a case mainly used for packing a plurality of single cells such as a lithium ion battery, a nickel cadmium battery, or a nickel metal hydride battery, and is made of a thin metal plate such as aluminum or an alloy thereof. Alternatively, the metal thin plate coated with a resin film such as a polyester film is molded into a predetermined shape. This type of assembled battery (packed battery) is used by connecting a large number in series or in parallel depending on the application. Therefore, in order to reduce the space when stacked or to facilitate stacking, The overall shape is thinned. Therefore, the case 1 is configured as a substantially rectangular or rectangular thin hollow body. An example thereof is schematically shown in FIG. 1, and the case 1 shown here is a recess that forms a substantial housing portion that houses a battery unit (not shown) made of a unit cell, a support plate, a substrate, or the like. It is comprised by the main-body part 2 of a cross-sectional shape, and the cover part 3 which closes the opening end.

  The main body 2 is formed by drawing a metal thin plate coated with the above-described resin film by a press and has a rectangular shape in a plan view, and its depth is the thickness of contents such as a unit cell or a support plate. It is somewhat deeper than that. FIG. 2 shows the shape of the bottom, and a leg 4 is formed on the bottom so as to protrude outward. In short, the leg portion 4 is a portion for supporting the main body portion 2 so that a gap is formed on the bottom surface side of the main body portion 2, and an appropriate number may be provided so as to achieve the purpose. In the example shown in FIG. 2, leg portions 4 are formed at the four corners of the bottom surface of the main body portion 2 as ridges bent along the corners thereof, which are formed by partially protruding the bottom surface of the main body portion 2. Has been. A view of one of the legs 4 as seen from the side of the case 1 is shown in FIG.

  A through hole (round hole) 5 for a connection terminal (not shown) is formed in the vicinity of one long side of the bottom surface of the main body 2. In the vicinity of the other long side on the opposite side, a connector through hole (long hole) 6 for connecting a node substrate (not shown) which is a component of the battery is formed. The bottom surface of the main body 2 does not have to be a flat surface as a whole, and may be formed by projecting inward a surface that is in close contact with and supports the internal battery unit or the like.

  On the other hand, the lid 3 is a thin plate-like member having a shape substantially equal to the opening shape of the main body 2, and is configured in a rectangular shape by a thin metal plate coated with a resin film that is the same material as the main body 2. . The peripheral portion of the lid portion 3 rises on the outer surface (upper surface) side, and forms a peripheral wall portion 7 that fits inside the opening end of the main body portion 2 described above, and on the upper end side of the peripheral wall portion 7 A flange portion 8 for winding is formed. And the height of the surrounding wall part 7 in the state which wound the flange part 8 around the opening end of the main-body part 2 is set so that it may become somewhat lower than the height of the leg part 4 in the main-body part 2 mentioned above. . The winding portion is shown as a partial cross-sectional view in FIG.

  Further, round holes 9 and long holes 10 corresponding to the round holes 5 and the long holes 6 in the main body 2 are formed in the vicinity of the long side of the lid 3. That is, in the state where the lid 3 is attached to the opening end of the main body 2, the round holes 5, 9 and the long holes 6, 10 are opposed to each other. Moreover, the center part of the cover part 3 is depressed on the inner surface side (lower surface side) over a predetermined area to form a depressed portion 11. This is because the content such as the battery unit is sandwiched and held between the main body 2 and the bottom surface in close contact with the internal battery unit or the like.

  The case 1 is configured by fitting the lid portion 3 configured as described above to the opening end of the main body portion 2 and winding the flange portion 8 around the opening end of the main body portion 2 in this state. That is, a battery unit including a single cell, a support plate, and a substrate is accommodated in the main body 2 in a desired posture, and the main body 2 is closed by covering the lid 3 with the battery unit. In this case, for example, as shown in FIG. 5, the power contact holes 13 and 14 in the battery unit 12 are made to coincide with the respective round holes 5 and 9 in the main body 2 and the lid 3, and the surrounding insulating members 15 and The cylindrical portions (boss portions) 17 and 18 formed in 16 are brought into close contact with the respective round holes 5 and 9 to be fitted. As a result, the relative position between the case 1 and the battery unit 12 therein is determined, and the movement of the battery unit 12 in the case 1 is prevented. In addition, since the battery unit 12 is clamped by the recessed part 11 in the cover part 3 and the bottom part inner surface in the main body part 2, the battery unit 12 in the case 1 does not rattle.

  In the assembled battery configured as described above using the case 1 according to the present invention, the shape of the region partitioned by the peripheral wall portion 7 in the lid portion 3 is substantially the same as the outer shape of the bottom portion in the main body portion 2. It has become. Therefore, when a plurality of assembled batteries are stacked in the same posture to form a battery stack, the bottom part of the adjacent assembled battery is fitted inside the lid 3. In that case, the leg portion 4 described above is formed on the bottom surface of the main body portion 2, and the leg portion 4 contacts the surface (upper surface) of the lid portion 3, so that the upper surface of the lid portion 3 and the bottom surface of the main body portion 2 In the meantime, a predetermined gap 19 is generated. This state is shown in FIG.

  In addition, since the height of the peripheral wall portion 7 after the tightening is performed is lower than the height of the leg portion 4 formed on the main body portion 2, the leg portion 4 is removed from the bottom outer peripheral portion of the main body portion 2. The portion is separated from the upper end edge of the peripheral wall portion 7. This state is shown in FIG. Accordingly, the gap 19 between the upper surface of the lid 3 and the bottom surface of the main body 2 is in an open state or in communication with the outside of the battery stack at a position away from the leg portion 4. It becomes a ventilation passage for cooling.

  As described above, according to the case 1 according to the present invention, since the cooling ventilation path can be secured between the stacked assembled batteries, the heat accompanying the charging / discharging of the battery unit 12 can be efficiently released to the outside, and the temperature rise or thermal runaway Can be avoided or suppressed. In addition, since the temperature does not rise excessively, the durability of the assembled battery can be improved and the temperature of each assembled battery in the stacked state is equalized to stabilize its charge / discharge capacity. In addition, it is possible to prevent the lifetime of any particular assembled battery from being reduced. Furthermore, when the above-described leg portion 4 is formed as a convex bead portion that is in close contact with the inner surface of the peripheral wall portion 7 and / or the upper end side (tip end side) portion of the lid portion 3, the strength of the bottom surface of the case 1 is improved. As a result, the strength of the assembled battery can be improved, and the relative position between the adjacent assembled batteries can be determined by the leg portion 4 and the peripheral wall portion 7, so that the assembled battery has good bondability or stackability. Can be.

  In addition, electrical conduction between the assembled batteries is performed by the connection terminals 20 inserted into the power contact holes 13 and 14 described above. As shown in FIG. 5 described above, the connection terminal 20 inserted into the upper power contact hole 13 protrudes to the upper side of the assembled battery, and its protruding end fits into the power contact hole 14 on the bottom side of the upper assembled battery. Can be combined. Therefore, the relative positions of the upper and lower assembled batteries are also determined by the connection terminal 20.

  Next, another example of the present invention will be described. The above-described example is an example in which the gap 19 serving as a cooling ventilation path between the stacked assembled batteries is secured by the leg 4 provided at the bottom of the case 1. Can be provided on the peripheral wall portion 7 of the lid portion 3. FIG. 8 shows a bottom surface shape in another example of the present invention. A stepped portion 21 is formed on the outer peripheral corner portion of the bottom surface by being stepped into the entire inner periphery. . The step portion 21 is a portion into which the upper end portion of the peripheral wall portion 7 in the lid portion 3 is inserted. Therefore, the cross-sectional shape of the step portion 21 is preferably a shape approximate to the cross-sectional shape of the upper end portion of the peripheral wall portion 7. . An example of the shape is shown in FIG. 9, and the state of engagement with the upper end of the peripheral wall 7 is shown in FIG.

  By engaging the step portion 21 with the upper end side (tip end side) portion of the peripheral wall portion 7, the bottom surface of the upper case 1 (assembled battery) and the lid portion 3 in the lower case 1 (assembled battery). A gap 19 is ensured between the upper surface of each of the layers. An opening for communicating the gap 19 with the outside is formed. That is, the process which makes those places recede to the inner side of case 1 is given to several places of the bottom part corner part of case 1, and it inclines with respect to the bottom face and side face of case 1, and connects these bottom face and side face. An inclined receding surface 22 is formed. The inclined receding surface 22 is for partially retracting the bottom corner portion of the case 1 from the stepped portion 21 described above. An example of the shape is shown in FIG. The relative position with respect to the peripheral wall portion 7 is shown in FIG. That is, as shown in FIG. 12, the inclined receding surface 22 is configured to be separated from the peripheral wall portion 7 of the adjacent case 1 when the cases 1 are overlapped with each other.

  The step portion 21 is a portion where curved surfaces having a large curvature are continuous, whereas the inclined receding surface 22 has a small curvature. Therefore, since the rigidity is relatively lowered in the vicinity of the inclined receding surface 22, a bead portion 23 for reinforcement is formed on the bottom surface of the case 1 along the inclined receding surface 22. The bead portion 23 is a portion of the bottom surface of the case 1 having a predetermined length along the inclined receding surface 22 that is linearly recessed inside the case 1. Rigidity is relatively large due to curing. The other configuration is the same as the example shown in FIGS. 1 to 7 described above, and is used for the assembled battery in the same manner as the above-described example.

  In the assembled battery configured using the case 1 according to the present invention shown in FIGS. 8 to 12, the contour shape of the region defined by the peripheral wall portion 7 in the lid portion 3 and the contour shape of the bottom portion are as follows. It almost matches. Therefore, when a plurality of assembled batteries are aligned to form a battery stack, the stepped portion 21 formed on the outer peripheral portion of the bottom surface becomes the inner surface of the peripheral wall portion 7 and / or the lower assembled battery. Riding on the upper end side (front end side) portion of the peripheral wall portion, the relative position in the plane direction parallel to the bottom surface is determined, and each assembled battery is stacked in that state. Therefore, the assemblability when assembling the battery stack is good.

  Further, since the upper assembled battery is mounted on the upper end of the peripheral wall portion 7, a gap 19 is formed between the upper and lower assembled batteries. In addition, the inclined receding surface 22 described above is formed at the bottom corner portion of the case 1, and the upper and lower assembled batteries are separated from each other at this portion. As a result, the upper surface of the lid 3 in the upper and lower assembled batteries The gap 19 between the bottom surface of the main body 2 is opened or communicated with the outside of the battery stack at the inclined receding surface 22, and therefore the gap 19 becomes a cooling ventilation path.

  Thus, even when configured as shown in FIG. 8 to FIG. 12, the cooling performance or heat dissipation performance of each assembled battery when stacked as a battery stack can be improved, which is the same as the specific example described above. The operation and effect of can be obtained. Further, since the bead portion 23 is formed in the bottom corner portion in addition to the inclined receding surface 22, the cooling performance or the heat radiation performance can be improved without impairing the rigidity of the case 1. Note that the electrical conduction between the assembled batteries is performed by the connection terminal 20 described above, and accordingly, the relative position of the assembled batteries is determined by the connection terminal 20 in the same manner as in the specific example described above.

  In each of the specific examples described above, the case where the assembled battery is stacked vertically has been described. However, the case 1 of the present invention may be a case for the assembled battery stacked in the horizontal direction, and is limited to the specific examples described above. Not. Further, the shape of the inclined receding surface 22 described above may be a shape of a curved surface having a small curvature or a flat surface, or may be a semi-cylindrical surface. What is necessary is just to be formed as an opening part which connects the clearance gap formed in this to the exterior. Moreover, the bead part 23 mentioned above will not be limited to the linear shape shown in the said specific example, if it has the bead shape which reinforces an inclination retreat surface and a peripheral part. And the leg part 4 mentioned above, the step part 21, and the surrounding wall part 7 are equivalent to the support part in this invention, Therefore The support part in this invention is formed in the peripheral part of the bottom face or upper surface of a case. If it exists, it is not limited to the thing of the structure shown in each said specific example.

  DESCRIPTION OF SYMBOLS 1 ... Case, 2 ... Main-body part, 3 ... Lid part, 4 ... Leg part, 5 ... Through-hole (round hole), 6 ... Through-hole for connectors (long hole), 7 ... Perimeter wall part, 8 ... Flange part, 9 ... round hole, 10 ... long hole, 11 ... hollow part, 12 ... battery unit, 13, 14 ... power contact hole, 15, 16 ... insulating member, 17, 18 ... cylindrical part (boss part), 19 ... gap, 20 ... Connection terminal, 21 ... Step part, 22 ... Inclined receding surface, 23 ... Bead part.

Claims (3)

In a battery case that is formed as a thin hollow body so as to accommodate a battery unit and is used by electrically connecting the battery units to each other in a stacked state,
In a stacked state, support portions interposed between the facing surfaces are formed so that a gap through which the cooling fluid flows is formed between the facing surfaces in the stacking direction. Formed in at least one of the peripheral parts,
And an opening for communicating the gap with the outside is formed on at least one of the mutually facing surfaces ,
The support portion includes a peripheral wall portion formed on the periphery of one of the surfaces facing each other so as to protrude toward the other surface, and an inner surface of the peripheral wall portion and / or a portion on the front end side of the peripheral wall portion. And a step formed on the periphery of the other surface so as to engage,
An inclined receding surface that is deformed so as to be separated from the peripheral wall portion is formed in the periphery of the other surface,
The battery case , wherein the opening is a portion where the inclined receding surface and the peripheral wall portion are separated from each other . At least one of the surfaces facing each other is fitted with any part of the constituent members of the battery unit to determine the relative position between the one surface and the battery unit, and The battery case according to claim 1, wherein a through-hole to be fixed is formed. Components of the cell unit, when placed around the prior SL power contact hole definitive battery unit together, in a state of being matched with the through hole and the power contact hole, fitted in the through-hole The battery case according to claim 2, further comprising insulating members connected together and / or connected.

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