BACKGROUND OF THE INVENTION

The invention relates to a cooling plate for the temperature control of at least one battery cell. Furthermore, the invention also relates to a battery system with such a cooling plate.

Cooling plates are known from EP0516280A1 for the temperature control of traction battery cells, having flow ducts covered by a flexible cover for the thermal contacting of the traction battery. Such cooling plates have the drawback that a reliable temperature control of the traction battery cells is not always possible.

SUMMARY OF THE INVENTION

The present invention describes a cooling plate for the temperature control of at least one battery cell, especially for a traction battery. The cooling plate comprises a frame with flow ducts designed for the flowing of a coolant through them and a flexibly configured cover. The flexibly configured cover bounds the flow ducts in fluid-tight manner and is provided for the thermal contacting of the at least one battery cell. According to the invention, the flow ducts comprise at least one perturbing contour, which is provided to increase the turbulence in the coolant flowing through the flow ducts. This has the benefit of improved cooling performance or temperature control ability as compared to the prior art. The increased turbulence which can be produced by means of the perturbing contours serves for more intense mixing of the coolant. In particular, a laminar flow formed by the coolant within the flow ducts, especially a laminar flow formed along a longitudinal direction of the flow ducts, is disrupted such that a temperature gradient perpendicular to the longitudinal direction is minimized. The perturbing contour produces for example a turbulent flow with eddy currents in the coolant. Preferably, the perturbing contour produces for example a flow with a Reynolds number over 100, preferably over 1000, especially preferably over 2000.

The cooling plate preferably comprises a first port, which is provided for a supply of the coolant. The cooling plate preferably comprises a second port, which is provided for a drainage or an outflow of the coolant. Especially preferably, the frame comprises the first port. Especially preferably, the frame comprises the second port. This has the benefit that the cooling plate is especially reliable and robust, especially being leakproof or tight.

By a coolant is meant especially preferably a liquid coolant. Preferably, the coolant comprises a mixture of water and glycol. Of course, however, other embodiments are possible with coolants comprising gases and/or aerosols.

The frame preferably comprises a plate, especially a plate formed largely rectangular. Preferably, the frame and/or the plate is formed at least partly from plastic. The geometry of the plate or the geometry of the cooling plate will depend in particular on the geometry of the battery cell being cooled, especially a dimension of the battery cell being cooled, so that the battery cell can be thermally contacted by the cooling plate. Preferably, the cooling plate or the plate is flat or largely flat. A flat cooling plate is provided for the thermal contacting on a flat side surface of the battery cell. It is also conceivable for the cooling plate or the plate to have a curvature. This has the advantage that an especially good thermal contacting of the battery cell is possible. In addition, it has the advantage that an especially stable and reliable mechanical contacting or connection between the battery cell and the cooling plate is possible.

The frame comprises flow ducts. By a flow duct is meant in particular a conduit formed for a coolant to flow through it, being especially elongated in shape. In particular, it should be understood that the flow duct has a much larger extension in a longitudinal direction than in a direction situated perpendicular to the longitudinal direction. In particular, a diameter of a flow cross section area of the flow duct oriented perpendicular to the longitudinal direction is significantly smaller than a length of the flow duct along the longitudinal direction. By a significantly greater first length than a second length is meant that the first length is larger by at least a factor of 10 than the second length, preferably by a factor of 20, especially preferably by a factor of 40. By a significantly smaller first length than a second length is meant that the first length is smaller by at least a factor of 10 than the second length, preferably by a factor of 20, especially preferably by a factor of 40.

In particular, a flow duct is formed open for at least a portion along its longitudinal direction. Preferably, openings or open areas of the flow duct are positioned such that they lie against the battery cell in the condition when mounted on the battery cell. In particular, it is conceivable that the openings or open areas of the flow ducts are arranged at least for a portion perpendicular or largely perpendicular to a normal to the cooling plate. By a first axis being arranged largely perpendicular to a second axis is meant that the first axis makes an angle with the second axis deviating not more than 8°, advantageously not more than 5°, especially advantageously not more than 2° from 90°.

Preferably, a flow duct each time comprises two webs arranged on the frame and/or preferably on the plate. Preferably, the webs run at least largely parallel to each other. Preferably, the two webs are in contact with the frame and/or with the plate in fluid-tight manner. In particular, a coolant flowing through the flow duct is bounded in fluid-tight manner by the webs and the frame or the plate. A web is a boundary wall of a flow duct. By a first axis being arranged largely parallel to a second axis is meant that the first axis makes an angle with the second axis deviating not more than 8°, advantageously not more than 5°, especially advantageously not more than 2° from 0°.

The flexibly configured cover is designed to bound the flow ducts in fluid-tight manner. In particular, the flexibly configured cover is designed to bound the open area or the open areas of a flow duct in fluid-tight manner. For example, the flexibly configured cover may contact the webs of a flow duct in fluid-tight manner, so that a coolant flowing through the flow duct is bounded by the webs, the flexibly configured cover and the frame or the plate in fluid-tight manner. This has the benefit of making possible an especially good temperature control of the battery cell, since heat can be transferred especially well between the battery cell and the coolant by the flexibly configured cover. In particular, the use of a sufficiently thin flexibly configured cover is possible, so that this has an especially slight thermal resistance.

By a flexibly configured cover is meant in particular a cover which is elastically or at least partly elastically deformable. In particular, a flexibly configured cover is deformable by a force acting upon it and designed to return at least partly to its original shape when the force goes away. A flexibly configured cover can be placed or flattened especially well against the at least one battery cell, especially to make thermal contact. This enables a more efficient cooling of the battery cell.

Preferably the frame comprises a plurality of flow ducts, preferably between 4 and 16 flow ducts, especially preferably between 8 and 12 flow ducts. The number of flow ducts depends in particular on the geometry of the battery cell being cooled, especially a dimension of the battery cell being cooled.

By a longitudinal direction of the flow duct is meant in particular a direction of principal lengthwise extension of the flow duct, preferably pointing in an intended direction of flow of the coolant and/or in a mean intended direction of flow of the coolant. By a longitudinal direction of the flow duct is meant in particular a mean direction over the respective longitudinal directions of the individual flow ducts. Preferably, all or nearly all of the flow ducts have the same or largely the same longitudinal direction.

Preferably, the cooling plate is made as a single piece with the frame. By a single piece is meant in this context in particular materially bonded, such as by a welding process and/or a gluing process, etc., and especially advantageously one which is molded on, such as by being made from a casting and/or being made in a single or multiple component injection molding process. Preferably, the cooling plate is formed as a single piece with the first port and/or the second port. This has the advantage that the cooling plate has a high mechanical stability.

Preferably, the frame comprises the first port and/or the second port. Preferably, the frame is formed as a single piece with the flow ducts and/or the first port and/or the second port. Preferably, at least one web of one flow duct is formed as a single piece with the frame and/or with the plate of the frame.

By a perturbing contour is meant in particular an element or component which changes a flow cross section area of a flow duct for a portion, especially one which reduces it. The perturbing contour is designed to disrupt a laminar flow through the flow duct, in particular to heighten the turbulence of the flow. Preferably, the perturbing contour is formed as a single piece with the frame and/or with the plate and/or with a web. For example, the perturbing contour may be formed as an extension of the frame and/or the plate and/or a web.

If the at least one perturbing contour deflects the coolant flowing through the flow duct at least partly in the direction toward the flexibly configured cover, the coolant will be mixed in the direction of the flexibly configured cover. In this way, a forming of laminar flow layers in the coolant is prevented. The coolant can take up a larger quantum of heat per unit of time and surface, so that a possible temperature control performance of the cooling plate is enhanced.

In one advantageous variant, a contour height of the at least one perturbing contour situated perpendicular to a longitudinal direction of the flow ducts increases at least for a portion along the longitudinal direction of the flow ducts. In this way, the turbulence can be increased in the coolant flowing through the flow ducts, without increasing the flow resistance too much. By selecting how quickly or greatly the contour height rises along the longitudinal direction, especially by selecting a gradient of the contour height, one can adjust the degree of turbulence and/or the flow resistance. The selection of how quickly or greatly the contour height rises along the longitudinal direction depends in particular on the technical requirements for the cooling plate, especially the requirements on temperature control performance, especially the cooling performance, and/or the requirements on the flow resistance of the cooling plate for the coolant.

A cooling plate in which the perturbing contour has a triangular cross section area parallel to the longitudinal direction is an especially easily produced variant of a cooling plate. Preferably, the triangular cross section area is formed as a right triangle. Preferably, the perturbing contour is arranged such that a first cathetus of the triangular cross section area is arranged parallel or largely parallel to the longitudinal direction. Especially preferably, the perturbing contour is arranged such that a second cathetus of the triangular cross section area is arranged perpendicular or largely perpendicular to the flexibly configured cover and/or the second cathetus is arranged parallel or largely parallel to a normal to the cooling plate.

Because a plurality of first perturbing contours in a respective flow duct are arranged in a first row along a longitudinal direction of the respective flow duct and a plurality of second perturbing contours in the respective flow duct are arranged in a second row along the longitudinal direction of the respective flow duct, a more even increasing of the turbulence across the entire cooling plate becomes possible. Preferably, the plurality of first perturbing contours in the first row are arranged uniformly or equidistant. Preferably, the plurality of second perturbing contours in the second row are arranged uniformly or equidistant. It is conceivable in variants for a further row or more than one further row to be arranged along the longitudinal direction of the respective flow duct each with a plurality of perturbing contours. This further enhances the uniformity of the turbulence increase.

If the second perturbing contours of the second row are offset from the first perturbing contours of the first row, this has the advantage that coolant flowing through the flow duct is deflected additionally in a direction which connects the first row to the second row. In particular, the coolant flowing through the flow duct is deflected additionally in a direction perpendicular to the longitudinal direction and parallel to the flexibly configured cover. For example, in this way it is possible for a flow of the coolant flowing through the flow duct to run largely along a zig zag line. In this way, the turbulence is further increased in the coolant flowing through the flow duct, so that the temperature control ability of the cooling plate can be further improved.

Especially advantageous for increasing the turbulence is a cooling plate in which each time four perturbing contours of a plurality of perturbing contours form a parallelogram. By four perturbing contours forming a parallelogram is meant that the four perturbing contours are arranged at the corners of an imaginary parallelogram. Especially advantageous is a parallelogram having an internal angle less than 90°.

The cooling plate is further improved when the flexibly configured cover comprises at least one film, preferably a plurality of films, especially one formed as a composite film. In this way, a good heat transfer between the coolant and the battery cell is assured for an especially durable seal of the flow ducts.

If the flexibly configured cover is materially bonded to the frame, especially with two webs bordering on a respective flow duct, this has the advantage that the fluid-tight sealing of the flow ducts by the flexibly configured cover is especially secure and reliable. By a materially bonded connection is meant in particular a connection by a sealing process, especially a hot sealing process. Preferably, a materially bonded connection may be a glue connection, a connection by vulcanization, a welded connection—especially a laser welded connection—and/or a soldered connection.

A battery system comprising a cooling plate according to the present invention and a battery module, wherein the battery module comprises at least one battery cell and the at least one battery cell is arranged on the flexibly configured cover so that a thermal contacting of the at least one battery cell and the flexibly configured cover is formed, has the advantage that the battery module has an especially good anticipated service life on account of the fact that the cooling plate can always provide the necessary cooling power.

