DE102006059989A1 - Arrangement for cooling battery, has multiple individual cells, which are assembled together for battery and individual cells have cylindrical housing form - Google Patents

Abstract

The arrangement has multiple individual cells (1.1,1.2,1.3,1.4,1.5,1.6,1.7), which are assembled together for the battery. The cells have a cylindrical housing form and are assembled for the battery such that the rotation axis of the cells are oriented parallel to each other. A base plate (3) is provided for the cells where cells stand perpendicular. The cells are in thermal contact with the base plate. The thermal contact of the cells to the base plate takes place over cooling element (2), which is arranged in the space of the dense packing. An independent claim is also included for a method for manufacturing an arrangement.

Description

The The invention relates to an arrangement for cooling one of a plurality of individual cells existing battery and a method of manufacturing the device.

It already such an arrangement is known in the prismatic Single cells are arranged side by side. Between these prismatic single cells each is a cooling element arranged by the resulting heat of the prismatic single cells in the area dissipated shall be. These prismatic single cells are on a base plate attached, which is in thermal contact with the cooling elements. For better heat dissipation This base plate is flowed through by a cooling medium.

Of the The present invention is based on the object of heat removal of single cells with cylindrical Gehauseform to improve.

These The object is according to the present invention according to claim 1 by an arrangement for cooling solved a battery consisting of several single cells, wherein the single cells are mounted together to the battery, wherein the Single cells of the battery cells with cylindrical housing shape are, with the individual cells assembled so to the battery are that the axes of rotation of the cylindrical single cells parallel oriented to each other, wherein the individual cells next to each other are arranged in the tightest packing, wherein the individual cells a base plate is present, wherein the single cells are vertical stand on the base plate, with the single cells in thermal Contact with the base plate, with the thermal contact the single cell is made to the base plate via cooling elements, which in the gussets of the densest packing of the individual cells are arranged, where the outer contour the cooling elements has a trigonal symmetry and the single cells on the cylindrical outsides thermally contact and wherein the base plate by means of a flowing cooling medium chilled becomes.

there it proves to be advantageous that such a battery join tight and compact leaves. In particular, you can the single cells and the cooling elements pressed tightly together, leaving a good mechanical Contact arises. This mechanical contact simultaneously promotes heat exchange, so that by the described arrangement a good heat dissipation is feasible. This results in a compact arrangement of this Single cells. Overall, the space requirement can be advantageous minimize. Furthermore, it proves to be advantageous that the Single cells can be efficiently clamped mechanically, so that gap formation between the fin and cell in consequence of thermal expansion the individual cells are largely avoided during operation of the battery can. Leg not under permanent compression held connections to lead these thermal expansions to problems in the contact of the individual cells with the associated Cooling elements. By the constructive avoidance of gap formation due to thermal expansion during operation of the battery can advantageously turn the heat dissipation be improved.

By the arrangement of the individual cells creates a compact design of Battery. By the arrangement of the cooling elements in the remaining spaces is Advantageously, the heat dissipation efficient realized.

In the gussets between each three parallel individual cells in the tightest packing are cooling elements arranged. These are in thermal contact with the base plate. Due to the arrangement of the individual cells with a cylindrical housing shape in closest packing results in the shape of the cooling elements such that these in a section perpendicular to the axes of the individual cells an outer contour having trigonal symmetry. The areas that make up the single cells Contact the curvature adapted to the cylindrical cells and therefore to the midline of the area in the longitudinal direction curved down.

Advantageous lets along this arrangement a compact and filled in the full area cross-section package of single cells and cooling elements describe. The cooling elements can consist for example of aluminum. By filling the package completely, let yourself also simply tense this package.

The cooling elements can be connected or simply juxtaposed be, with the cooling elements with the single cells first be radially clamped and thereby held together. After that the finished cell pack is axially connected to the cooling plate.

at The arrangement according to claim 2 are advantageous, the individual cells mounted on both sides of the base plate.

As a result, it is advantageously achieved that the area for heat transfer is better utilized in the base plate cooled by the flowing cooling medium. Compared to the prior art, in which the individual cells are arranged only on one side of the base plate, it turns out that in this embodiment it is not necessary to thermally isolate the base plate on the one side to the available cooling energy for To have the heat dissipated from the battery. Rather, in the present invention, the full area of the base plate is used for heat transfer from the battery.

at the arrangement according to claim 3, the contacting of the poles takes place seen from the single cell on the base plate opposite Page.

Advantageous this results in the possibility a simple contact. This can be from a single cell each with individual connecting elements to the next single cell. By the defined arrangement of the individual cells in the package is it also possible provide a bonding plate. With such a plate can be Make the contact with reduced time.

at the embodiment according to claim 4, the base plate is in thermal Contact to at least one cooling line, which is flowed through by a coolant.

there it proves to be advantageous that the cooling of the base plate and thus improves the heat dissipation becomes. It can From the prior art already known measures can be realized as For example, the broadening of the cross section for the flowing cooling medium in the area of centralized single cells or use of guide vanes and flow resistances.

The cooling line has at least one inlet and at least one outlet.

at The embodiment according to claim 5, the base plate an at least Two-part construction on, with the two parts in the manner of a bottom part sealingly connected to each other with a lid part, wherein between the bottom part and the cover part, a continuous planar cavity arises from a coolant flows through becomes.

Advantageous it is not necessary in this embodiment, the base plate to bring in thermal contact with a cooling line, because the interior of the base plate is flowed through directly by the coolant.

at The embodiment according to claim 6, the arrangement of the individual cells with the cooling elements by means of tension bands braced together.

Advantageous results from the clamping a compact design, in the also gap formation as a result of thermal expansion in operation can be largely avoided. As a result, the thermal contact with the cooling elements and thus also the heat dissipation ensured during operation of the battery.

at The configuration of the arrangement according to claim 7, the outer cooling elements connected together so that the individual cells with the cooling elements even without using an extra Clamping band are securely clamped under pressure prestressing.

Advantageous have in this embodiment, the outer cooling elements elastic connectors as an integral part of these cooling elements. By a Connection of the outer cooling elements in this case, the mechanical tension of the Package.

at the embodiment according to claim 8, the cooling elements made of metal and are at the contact surfaces electrically isolated against the single cells.

The Metal may be, for example, aluminum or magnesium. These Metals have good thermal conduction properties, are relatively easy to handle in production and are light, so that the total weight of the battery is limited.

The electrical insulation against the single cells can be realized by the housing the individual cells are electrically floating.

Come For example, Li-ion cells used as single cells, this is usually not the case. In this case, the contact surfaces with be provided an electrically insulating material.

According to the embodiment according to claim 9, to between the cooling elements and the individual cells Mica film can be arranged.

A commercial For example, thermally highly conductive mica film has a thickness of 0.14 mm. This mica foil can be double-layered around the single cell to be beaten around.

at This type of insulation proves to be advantageous in that the mica foil is not flammable, so that even in case of fire the thermal insulation is maintained. In addition, the mica film is comparatively inexpensive, has good insulation and is durable.

Alternatively, the electrical insulation can be realized in an arrangement according to claim 10, in that the cooling elements consist of a metallic base body, which is made of a plastic give is.

Of the metallic body For example, it can be made of aluminum or magnesium again.

Of the metallic body can be made in this embodiment by the metallic body the individual cooling elements Bars formed be, for example, by friction welding with corresponding holes or Holes of the base plate thermally and mechanically connected become. The base plate may for example consist of aluminum. The metallic basic body the cooling elements can also Made of aluminum. In the connection by means of friction welding is It is also conceivable that the metallic base body of the individual cooling elements consist of copper.

alternative to the metallic bars can the main body also be designed as a heat pipe. At cheap automatically manufactured heat pipes shows that these are not at the bar ends cool well. Therefore, this embodiment is suitable for single cells, which are mounted on both sides of the base plate. In this case can the base plate are provided with precisely fitting through holes. The rod-shaped Heat pipe rods be through these holes put through and connected in the middle with the base plate. Suitable for this For example, the thermal shrinking. Here are the Heat pipes cooled strongly before mounting and heated the base plate. When mounting the single cells on both sides of the base plate shows here that the number of components is halved. Using The heat pipes show a good cooling, as the thermal gradient along the cooling element according to this cooling principle is minimal. Furthermore the possibility arises a weight reduction, because the heat pipe is a hollow body.

at the embodiment according to claim 11, the cooling elements plates with each other connected, extending from the edge of a cooling element to the adjacent Extend edge of another cooling element, these plates contain at least one mineral. Such plates can for example, be mica plates.

This has advantages in that no plastic compound on this Spot must be made, at the wall thickness low is. Otherwise it would be the packing density for manufacturing reasons limited. The mica plates have in turn, the advantage of fire resistance, so that with this embodiment also provide benefits in case of fire.

claim 12 relates to a method for producing an arrangement according to claim 10 or 11, wherein rod-shaped metallic bars as parts of cooling elements at least thermally connected to a metallic base plate be, taking the metallic parts before mounting the cells with an injection molding process wrapped in plastic become.

there have to the places for the later assembly the individual cells are kept free. So there is a "hedgehog" from the metallic ones primitives the cooling elements, the following be overmoulded with plastic. The shape must be designed in this way be that one subsequent Assembly of single cells possible is.

claim 13 relates to a method of manufacturing an assembly according to claim 10 or 11, wherein a plastic jacket of the metallic parts prefabricated by using a flat prefabricated plastic cover over the Cooling plate and precisely fitting prefabricated sleeves made of plastic over the metallic cooling fins all metal parts of the cooling device be covered electrically insulating. Sleeves and cooling plate cover may also be present the assembly made as a part and (almost like a glove) in one step over pushed the prefabricated heat sink become.

at The embodiment according to claim 13 is an injection molding process. Again, a "hedgehog" made of the metallic bodies of the first Cooling elements.

Farther Be separate the plastic sheathing of this metallic body in an injection molding process hergstellt. Advantageously, these individual sleeves are welded together so that this in a single operation as the only part on the "hedgehog" of the metallic body of the cooling elements be pushed. This welding can be done by means of a cover done, which simultaneously causes a cover of the base plate and thus also this electrically isolated against the individual cells.

Subsequently, will the process for producing the battery as a whole is explained by way of example.

Becomes the "hedgehog" prefabricated, the diameter must be the single cells are smaller than the openings in the "hedgehog." This is through the tolerances conditional. Nevertheless, in order to achieve a good heat conduction, the Single cells pressed together with the surrounding cooling elements be, for example with the help of a strap around the cell pack around.

In the embodiment of a method for producing an arrangement according to one of the Proverbs 1 to 11, the individual cells and the cooling elements located between the individual cells are first arranged to one another in layers, wherein then this package is connected to the base plate.

This Method is suitable for cooling elements, not passed through the base plate or with positive fit with this be connected. The fridge is mounted simultaneously with the cells by alternating layers from single cells and cooling elements one above the other be placed. The finished stack is then with a rotating Clamping band radially clamped. Subsequently, the cooling elements for example, by exciting expansion screws axially with the base plate anchored. The flat end faces of the cooling elements are thus mechanical force fit pressed onto the base plate. The tolerance of the hole in the cooling elements must be chosen be that a geometric offset of the expansion screws from the center the trigonal gusset according to the tolerances of the individual cells and the cooling elements is possible.

Advantageous the radial and axial tension of the stack becomes simultaneously carried out, to allow a tolerance compensation in both directions.

By This procedure described creates an axially frictional connection.

For example by gluing, welding, friction welding, soldering or thermal shrinking leaves itself an axially positive Connection of the cooling elements achieve with the base plate. The gluing is here, however only conditionally long-term resistant. A form-fitting Connection is also possible through corresponding recesses in the base plate.

at This approach is initially the "cooling" complete with electrical Made of insulation, the openings has, which are larger according to the tolerances than the individual cells. These are in these openings plugged. The stack is then distorted with a strap so that the cells are fixed to the cooling fins are pressed. This results in a slight change in shape of the cooling elements until they rest against the individual cells.

These strain requires use enough elastic or ductile materials for the cooling elements. This is for example through the use of cooling fins made of copper or aluminum. In addition, part of the necessary strain by a slight deflection of the cooling elements in the lower area near the base plate can be achieved. Between the single cells and the Base plate is required a certain distance of a few millimeters in length to ensure the electrical insulation to the base plate and one To create space for the intake of gases which in the event of damage can escape the floor of the cell. This is especially true for the common Li-ion cells.

In an example of 7 cells with a diameter of 41 each mm with a tolerance of + -0.2 mm in hexagonal arrangement results in a "hedgehog" with 12 cooling elements with a diameter the metal bars of 5 mm. The positional deviation of the cooling elements on the base plate should be 0.05 mm. The distance of the individual cells to the base plate should 5 mm. This results in a maximum deformation of the outer cooling elements in height the floors of individual cells: 0.2 mm / 2 (inner single cell in the pack) + 0.2 mm / 2 (outer single cell in Pack) + 0.05 mm (cooling element) = 0.25 mm. As a result, the cooling element by the tension is deformed so that the center of the cooling element is a maximum of a Height of 5 mm offset by 0.25 mm in the horizontal.

A Such deformation can be easily performed even under production conditions carried out be because the stiffness of the individual cells is many times higher than that of the cooling elements. Also, the necessary deformation can be reduced even if as plastic for the Kühlelementummantelung a material with height elasticity is used, such as good heat conductive silicone rubber.

in the In connection with claim 11, an arrangement has already been mentioned, at the individual cooling elements at the edges of which are interconnected by means of mica plates. By this configuration is advantageously achieved that the distance between the individual cells can be minimized.

Since the injection molding of plastics must not fall below a certain minimum thickness in order to ensure a reliable electrical isolation between the individual cells, even under high voltage, are at the points where the individual cells are closest (in heax -agonal arrangement around an inner Single cell around), thin and very well insulating plates on mica bases (for example MICA) with rectangular cut used in the body of solids. For the cooling elements, which are positioned in the gussets, this means that these mica plates, starting from the edges, connect this cooling element to the corresponding edge of another cooling element. It proves to be advantageous that these mica sheets are fire-resistant, so that even in case of damage in a battery fire electrical insulation between adjacent individual cells is maintained. In the mounted state, an internally arranged single cell of the battery pack is then surrounded by six rectangular mica plates over the entire height of the cylindrical housing. In the six spaces at the abutting edges of the mica plates also touch over the entire height of the cylindrical body a total of six plastic body of the cooling elements, the cell housing.

When example for The gain in space results in an arrangement with 10 individual cells with a diameter of 41 mm in one row of the battery Distance with a pure plastic insulation of 2 mm. The total length of the Arrangement is 10 x 41 mm + 8 · 2 mm = 426 mm (100%). Be the plastic insulation as described replaced by mica sheets with a thickness of 0.3 mm, the the cell housings abut, results in a total length of the arrangement of 10 x 41 mm + 8 · 0.3 mm = 412.4 mm (96.8%).

The Mica plates can in the production of trigonal plastic sleeves of the cooling elements simultaneously with these are connected by partial encapsulation and simultaneously or afterwards along with the pods be mounted on the metallic "hedgehog".

It is possible, too, to make the separately manufactured plastic sleeves so that they truncated in the trigonal rotational symmetric cross-sectional area Contain corners that are provided with slots in the later rectangular mica plates can be inserted.

In order to This results in a finished honeycomb structure, in which then the Single cells can be used. The advantage here is that at the later radial clamping of the cell pack the mineral mica plates substantially be charged on pressure and not on train. Nevertheless, in the case the positive Fix the mica plates in grooves to sufficient tolerances to pay attention and if possible for the Plastic to choose a material with rubbery elasticity.

One embodiment the invention is shown in the drawing. Showing:

1 an example of the battery composed of single cells with cooling elements and a base plate,

2 a plan view of the arrangement according to 1 .

3 a separate representation of the arrangement of the cooling elements,

4 an example of the design of a base plate with a cooling tube,

5 another example of the design of a base plate with a cooling tube,

6 another example of the design of a base plate with a cooling tube,

7 another example of the design of a base plate with a cooling tube,

8th an example of a multi-part base plate, the interior of which flows through a cooling medium,

9 a tension of the individual cells

10 a first example of a current-carrying contact of the individual cells with cell connectors,

11 a further example of an additional low-current carrying contact with a circuit board,

12 a schematic diagram of the battery with housing and connections for cooling.

1 shows an embodiment of the single cells 1 with cooling elements 2 as well as a base plate 3 assembled battery in a perspective view.

It can be seen that is between the individual cells 1 cooling elements 2 are located. These cooling elements 2 For example, they can be made of aluminum. As a result, the weight of the battery is not significantly increased. At the same time, the cooling elements made of this material have a good thermal conductivity. These cooling elements 2 are in thermal contact with the base plate 3 ,

The single cells 1 are arranged such that in the arrangement of the single cells 1 seven of these single cells ( 1.1 . 1.2 . 1.3 . 1.4 . 1.5 . 1.6 . 1.7 ) define the vertices of a uniform hexagon in a section transverse to their longitudinal direction ( 1.1 . 1.2 . 1.3 . 1.4 . 1.5 . 1.6 ), whereby one of the single cells ( 1.7 ) is arranged in the middle of this hexagon.

Furthermore, it can be seen that on both sides of the base plate 3 an arrangement of the individual cells 1 with appropriate cooling elements 2 is appropriate.

This will make the heat transfer surface the base plate 3 optimally used for cooling the individual cells 1 the battery.

2 shows the arrangement of 1 in a top view. The arrangement of the individual cells 1.1 . 1.2 . 1.3 . 1.4 . 1.5 . 1.6 such as 1.7 is again clarified.

You can also see that one in the middle of the package of single cells 1 single cell 1.8 of six cooling elements 2 is surrounded, which have the shape of a uniform triangle in a section transverse to the longitudinal direction. The sides of this uniform triangle are curved concavely in a viewing direction from the outside to the respective side, wherein the radius of curvature of the concave curvature corresponds to the radius of the cylindrical individual cells.

The cooling elements 2 are still dimensioned so that six of these cooling elements 2 the single cell 1.8 completely enclose.

The cooling elements 2 are in thermal contact with the base plate 3 , As a result, the heat of the individual cells can advantageously be dissipated efficiently.

3 shows again in a representation without the single cells 1 as well as the base plate 3 the arrangement of the cooling elements 2 in a perspective view. In the presentation of the 3 are only the cooling elements with the reference numeral 2 referred to completely enclose a single cell in its assembled state. The other cooling elements are not provided with a reference numeral.

4 shows a first embodiment in which the base plate 3 with a cooling tube 4 is provided. This cooling tube 4 For example, it can have a diameter of 6 mm and can be flown through with R744 (CO2) as the coolant.

5 shows a further embodiment of an embodiment of a base plate 3 with an associated cooling tube 4 , This cooling tube 4 the representation of 5 can have a diameter of 14 mm and can be flowed through with the coolant R134a.

6 shows a further embodiment of a base plate 3 with an associated cooling tube 4 , This six-parallel-flow-through cooling tube, for example, have a cross section 7 mm. In the embodiment according to 6 In turn, the coolant R134a can be used. Furthermore, in the illustration of the 6 another supply line 5 as well as a return 6 to see for the coolant. It can be seen that the supply line 5 as well as the return line 6 in the assembled state parallel to the single cells 1 the battery are arranged.

7 shows a further embodiment of the base plate 3 with a cooling tube 4 , Here is the cooling tube 4 on the base plate 3 designed as a double tube. The cooling tube 4 can have a cross section of 6 mm. It is again the supply line 5 as well as the return line 6 to see.

8th shows a further embodiment of the base plate 3 , Here is the base plate 3 from a bottom part 3.1 and a lid part 3.2 produced. The bottom part 3.1 and the lid part 3.2 are shaped so that they can be joined together sealingly, being inside the base plate 3 results in a continuous flow with a cooling medium. The bottom part 3.1 and the lid part 3.2 For example, they can be milled out or made as castings.

It are also the positions for the single cells as well as the cooling elements to recognize.

9 shows an arrangement of single cells 1 , Cooling elements 2 as well as a base plate 3 with straps 7 and 8th held together. Furthermore, there are filling elements 9 and 10 to be seen, which are introduced with, so that the tension bands 7 and 8th sufficient pressure on the arrangement of the individual cells 1 with the cooling elements 2 exercise. The filling elements 9 and 10 are formed in this example as tubes that allow subsequent assembly of the cell pack with the battery case via expansion bolts, threaded rods or bolts.

10 shows a first way of electrical contacting, in which the contacts of the individual cells with cell connectors 11 . 12 be plated through from one single cell to the next.

11 shows a further possibility in which cell connector boards are present for contacting the individual cells.

Both in the embodiment according to 10 as well as in the design 11 the contacting of the individual cells takes place 1 on the base plate 3 opposite side.

In the presentation of the 11 you can still see that two more boards 14 and 15 present are the monitoring of single cells 1 serve. These boards are advantageously integrated into the battery.

12 shows a thermally and electrically isolated battery with a metal housing 17 and a housing cover 16 , From the housing cover 16 are the connections of the supply line 5 and the return 6 to see for the cooling medium.

Claims (14)

Arrangement for cooling one of several individual cells ( 1 ) existing battery, whereby the single cells ( 1 ) are mounted together to the battery, wherein the single cells ( 1 ) have a cylindrical housing shape, wherein the individual cells ( 1 ) are assembled to the battery such that the axes of rotation of the individual cells ( 1 ) are oriented parallel to one another, wherein the individual cells ( 1 ) are arranged next to each other in the densest packing, with the individual cells ( 1 ) a base plate ( 3 ), the individual cells ( 1 ) perpendicular to the base plate ( 3 ), whereby the single cells ( 1 . 2 ) in thermal contact with the base plate ( 3 ), wherein the thermal contacting of the individual cells ( 1 ) to the base plate ( 3 ) via cooling elements ( 2 ) carried out in the interstices of the densest packing of the individual cells ( 1 ), wherein the outer contour of the cooling elements ( 2 ) has a trigonal symmetry and the single cells ( 1 ) thermally contact on the cylindrical outer sides and wherein the base plate ( 3 ) is cooled by means of a flowing cooling medium. Arrangement according to claim 1, characterized in that the individual cells ( 1 ) on both sides of the base plate ( 3 ) are mounted. Arrangement according to one of the preceding claims, characterized in that from the Einzelle ( 1 ), the contacting of the poles of the individual cells ( 1 ) at the base plate ( 3 ) on the opposite side. Arrangement according to one of the preceding claims, characterized in that the base plate ( 3 ) in thermal contact with at least one cooling line ( 4 ), which is flowed through by a coolant. Arrangement according to one of the preceding claims, characterized in that the base plate ( 3 ) an at least two-part construction ( 3.1 . 3.2 ), wherein the two parts in the manner of a bottom part ( 3.1 ) with a cover part ( 3.2 ) are sealingly connected to each other, wherein between bottom part ( 3.1 ) and lid part ( 3.2 ) creates a continuous planar cavity, which is flowed through by a coolant. Arrangement according to one of the preceding addresses, characterized in that the arrangement of the individual cells ( 1 ) with the cooling elements ( 2 ) by means of clamping bands ( 7 . 8th ) are braced together. Arrangement according to one of the preceding claims, characterized in that the outer cooling elements ( 2 ) are interconnected in such a way that the individual cells ( 1 ) with the cooling elements ( 2 ) are prestressed under compressive stress. Arrangement according to one of the preceding claims, characterized in that the cooling elements ( 2 ) consist of metal and at the contact surfaces against the individual cells ( 1 ) are electrically isolated. Arrangement according to claim 8, characterized in that between the cooling elements ( 2 ) and the single cells ( 1 ) a film is arranged, which contains mineral constituents. Arrangement according to claim 8, characterized in that the cooling elements ( 2 ) consist of a metallic base body, which is surrounded by a plastic. Arrangement according to one of claims 1 to 10, characterized in that the cooling elements ( 2 ) are interconnected by plates extending from the edge of a cooling element ( 2 ) to the adjacent edge of another cooling element ( 2 ), these plates containing at least one mineral. Method for producing an arrangement according to claim 10 or 11, characterized in that rod-shaped metallic rods are used as parts of cooling elements ( 2 ) at least thermally with a metallic base plate ( 3 ), wherein the metallic parts before assembly of the individual cells ( 1 ) are wrapped with an injection molding with plastic. Method for producing an arrangement according to claim 10 or 11, characterized in that a plastic coating of the metallic parts is prefabricated by plastic existing sleeves of the metallic body of the cooling elements ( 2 ) via a plastic cover of the metallic base plate ( 3 ), wherein this plastic sheath is pushed over the metallic parts in one step. Method for producing an arrangement according to one of Claims 1 to 11, characterized in that the individual cells ( 1 ) as well as between the individual cells ( 1 ) located cooling elements ( 2 ) are arranged to each other, wherein then this package with the base plate ( 3 ) is connected.