Temperature control system for lithium-ion battery cells

Abstract

The invention relates to a temperature control system for effectively cooling and heating rechargeable battery cells, in particular lithium (Li) ion batteries, wherein the temperature control module comprises a housing (1) made of a polymer material, the housing surrounds at least one heat-conducting layer made of a unidirectional carbon fiber composite material (2), and has guide channels (3) for conveying a heat transfer medium on two opposite edge regions of a main surface of the housing, the guide channels (3) extending from one end to the other along the edge region; preferably, at least two layers made of a unidirectional carbon fiber composite material (2) arranged one above the other are provided, an intermediate layer (7) having flow channels (8) being located between the layers, the flow channels connecting the guide channels (3) to each other.

Description

Technical Field

[0001] The invention relates to an efficient temperature control system for cooling and heating rechargeable battery cells, in particular rechargeable lithium (Li) ion batteries (LIBs). Background Art

[0002] LIBs have a high energy density at a relatively low weight and space requirement. LIBs are therefore already used in a wide range of applications for efficient energy storage. A particularly prominent application example is electromobility, for example as an energy source in electric vehicles or so-called hybrid vehicles.

[0003] Typically, for operation, a certain number of battery cells are combined into a battery module and two or more battery modules are combined into a battery pack. Cells and / or modules can be connected in series and / or in parallel.

[0004] There are different sizes and designs of battery cells, for example cylindrical cells or flat cells, such as prismatic cells or bag cells (coffee bag cells). In bag cells, a flexible housing is used, which usually consists of an aluminum foil that is plastic-coated on both sides. Typical bag cell dimensions are 350 mm×100 mm. Flat cells, such as bag cells or prismatic cells, are preferred with regard to better heat dissipation and stackability.

[0005] The typical construction of a LIB is as follows, starting from the anode side:

[0006] an anode (usually copper) having a flow discharger which is coated with an active material (usually graphite) at least on the side facing the cathode,

[0007] - a separator for electronic separation of the electrodes, but said separator being permeable to Li ions, and

[0008] a cathode (usually aluminum) having a current discharger coated at least on the anode side with an active material that releases Li ions when the cell is charged, and

[0009] An electrolyte (usually liquid or solid) which acts as a medium between the reactions at the electrodes and ensures the transport of the Li ions.

[0010] Suitable materials for the active materials of the cathode or anode, separator and electrolyte are known in the art.

[0011] Maintaining a certain temperature range is of central importance for the operability and safety of LIBs, but also for all other types of rechargeable batteries. Thermal management of rechargeable battery cells is an important criterion in order to ensure normal operation with optimized power output and service life.

[0012] It is generally important to operate lithium-ion battery cells within a defined temperature range between 15°C and 35°C in order to avoid premature aging of the battery cells and to ensure a high cycle life. The industry-required charging cycles of up to 1,600 full cycles over a 10-year service life can only be achieved if the battery system is regularly operated within the ideal temperature range. Therefore, a battery system which has lost 20% of its storage capacity in its delivery state (Begin of Life, BoL) and therefore only has a maximum of 80% of the original cell capacity (State of Health, SoH) when fully charged is no longer usable for automotive applications (End of Life, EoL).

[0013] In every season, in summer and also in winter, appropriate temperature control of the battery cells must ensure that the cells can be operated in a constant temperature window between 15° C. and 35° C., with the optimum operating temperature being 25° C. If the battery is operated continuously at 40° C., for example, aging is accelerated by up to 50%.

[0014] It should be taken into account that the thermal properties of battery cells are strongly anisotropic. Perpendicular to the cell surface, the low thermal conductivity of the separator in the case of polyethylene films of approximately 1 W / mK determines the thermal conductivity of the cell stack or of the wound cell roll in cylindrical cells. In the plane of bag-shaped and prismatic cells or in the height of cylindrical cells, the thermal conductivity is determined by the metallic flow conductors, which are approximately 30 W / mK.

[0015] Another problem is the desire of the drivers of electric vehicles to keep the charging cycles at the charging station as short as possible. In the near future, charging systems with a supply voltage of 800 V will already be available, with which high charging rates (C-rates) of up to 3C to 5C can be achieved. Such high C-rates lead to an increase in the flow line density around the contact area of ​​the electrodes and ultimately to a strong heating of the entire unit.

[0016] Temperatures above 80° C. must be avoided in any case, since in this range the electrolyte layer around the graphite particles of the anode is reduced. Generally, temperatures above 60° C. should already be avoided. It should be taken into account here that in hot countries, the ambient temperature and the emission of heat from the road can already lead to such high heating.

[0017] Another important aspect for accelerated cell aging is the temperature uniformity over the cell surface and cell thickness in addition to the absolute operating temperature. A temperature drop is observed over the cell surface, with the highest temperatures in the area of ​​the electrode contacts. This different heat distribution leads to mechanical stresses inside the cell that can shorten the service life.

[0018] High charging or discharging currents such as those currently being sought produce an increased flow line density in the region of the electrode connection contacts, which leads to increased heating in this region. This ultimately results in mechanical stresses in the anode or cathode coating, which can, on the one hand, directly damage the anode particles in particular, and, on the other hand, can lead to a loss of electrical contact between the particles due to expansion and contraction, and ultimately also to detachment of the coating from the flow deflector foil and thus to a loss of electrical contact between the coating and the flow deflector. It is therefore necessary to remove heat from the electrode contact region and to ensure that the heat distribution is as uniform as possible over the cell surface or cell thickness.

[0019] The thermal management of battery systems also takes into account vehicle operation at low temperatures. At low temperatures, in particular below 0° C., the cell voltage decreases significantly. Since the cell voltage is no longer sufficient for normal driving operation at temperatures below 10° C., the range of the vehicle is significantly limited.

[0020] The operating voltage of the LIB is typically in the range between 2.7 V and 4.2 V. As the viscosity of the electrolyte increases when the temperature drops, the ionic conductivity of the electrolyte and thus the cell voltage decreases. At approximately 2.7 V, the lower cut-off voltage of the cell is reached and further operation of the cell is therefore no longer possible for safety reasons.

[0021] In addition to a reduction in cell capacity, charging of battery cells at low temperatures can also lead to so-called lithium plating of the anode. Lithium plating is based on the fact that both the cathode and the anode have the physical ability to bind lithium ions. During charging, the electric field forces the ions to migrate from the cathode to the anode, where they are incorporated into the lattice structure of the active material, such as graphite.

[0022] In particular, at low temperatures, lithium ions (instead of being introduced into the anode as desired) form metallic lithium, which is deposited on the anode and is therefore no longer available for the charging process. This loss of circulated lithium ions reduces the effective power of the battery and can, in the worst case, lead to so-called "thermal runaway" with combustion and explosion of the cell. Summary of the invention

[0023] From the above embodiments, it can be seen that for optimal thermal management of the battery system, in addition to the cooling function at high temperatures and / or high charging rates, heating of the cells at low temperatures is also required. Therefore, a temperature control module is desirable, which can effectively perform both cooling and heating functions. To this end, the temperature control module should have the best possible thermal contact with the surface of the battery cells.

[0024] Therefore, a suitable temperature control module should have the following characteristics:

[0025] - The temperature control module should be as slender and light as possible in structure;

[0026] – The temperature control module should be mechanically self-supporting but allow a certain flexibility with respect to torsion and bending;

[0027] - The temperature control module must be able to flow through a liquid or gaseous heat transfer medium for temperature control;

[0028] - the module should preferably be able to compensate for temperature inhomogeneities (temperature gradients) on the surface of the battery cells;

[0029] The temperature control module should have an elastically deformable surface layer for better connection to uneven surfaces and for uniform distribution of the pressure load on the anode layer of the battery stack;

[0030] The temperature control module should have a certain mechanical flexibility in order to be able to adapt to possible dimensional changes of the cell during charging / discharging, as is the case in particular with pouch cells;

[0031] - The temperature control module should be able to directly cool or heat the cell contacts of the battery cells.

[0032] The object is achieved by a temperature control module for cooling or heating a battery cell according to the invention, the temperature control module having a housing made of a polymer material, and the housing comprising two opposite main surfaces, the main surfaces being connected to each other along their edges, and guide channels for a heat transfer fluid being respectively arranged on two opposite edge regions of the main surfaces, the guide channels extending along the edges, and at least one heat conducting layer made of a unidirectional carbon fiber composite material being arranged in the interior of the module, the heat conducting layer extending on the module surface between the guide channels.

[0033] The thickness of the temperature control module should be as small as possible in order not to unnecessarily increase the space requirement of the battery system equipped with the temperature control module. Therefore, a flat temperature control module is desirable, the thickness of which is thin relative to the other dimensions of the temperature control module, such as the length, width or diameter. The shape of the temperature control module depends on the shape of the battery cell, in which it is used. For flat battery cells, a rectangular basic shape is suitable. However, other shapes are also possible, such as square, round, etc.

[0034] The housing surrounds the components of the module located inside. The housing has two opposite main surfaces, which are connected to each other along their edges. The connection can be carried out via the side surfaces.

[0035] The housing with the edge region is made of an at least partially flexible polymer material, such as a silicone elastomer or a polyurethane elastomer. The partially flexible polymer material preferably has a Shore A hardness of A20 to A60 or a Shore hardness of 00 of 0020 to 0080. For battery cells or battery cell stacks with structured uneven surfaces, for example, a softer polymer material can be used for the housing, which can be adapted more easily to the surface structure of the battery, so that good contact between the temperature control module and the surface of the battery cell can be ensured. Good contact between the temperature control module and the battery cell is desirable for a heat transfer that is as efficient as possible.

[0036] In addition to compensating for surface irregularities of the battery cells, the housing provides for a uniform pressure transfer to the cells. For example, a pressure of 0.1 MPa to 0.5 MPa can be reliably transmitted and complete resetting can be ensured when the pressure is released. The housing can thus suppress dimensional changes during charging / discharging and stabilize the anode and cathode coatings on the flow deflector.

[0037] Along two opposite edge regions of the main surface, guide channels for conveying a heat transfer medium extend respectively. The guide channels can respectively have an inlet opening and an outlet opening for the heat transfer medium. If the guide channels are connected to each other, one guide channel can have an inlet opening and the other guide channel can have an outlet opening.

[0038] The access opening is provided with a connection to the cooling / heating system, which connection can be formed directly onto the housing.

[0039] At least one heat-conducting layer of unidirectional carbon fiber composite material is arranged between the main surfaces of the housing. The layer of unidirectional carbon fiber composite material is characterized by a high thermal conductivity in the fiber direction. The fibers are thus oriented parallel to the cell contacts of the battery cells to be temperature-controlled, so that the heat can be distributed and uniformly distributed over the cell surface.

[0040] By orienting the fibers in parallel, heat can be conducted away from the thermally particularly loaded contact areas of the unit, whereby the contact areas are freed of heat, the heat is distributed more evenly over the total area and overall cooling of the total area is achieved. In addition, the layer made of carbon fiber composite material acts as a partially flexible support structure for other module components.

[0041] The layer composed of carbon fiber composite material can be composed of a unidirectional non-woven layer composed of carbon fibers in a thermosetting plastic or thermoplastic matrix. Typically, the carbon fiber non-woven layer can be constructed from a plurality of layers composed of carbon fibers.

[0042] The thickness of the layer composed of carbon fiber composite material is typically 0.1 mm to 0.5 mm, preferably 0.2 mm to 0.3 mm. For example, the layer composed of carbon fiber composite material can be composed of a unidirectional non-woven layer composed of carbon fibers in a silicone matrix.

[0043] If necessary, the flexibility of the carbon fiber composite material layer can be increased, for example in the case where unevenness of the surface of the battery cell is to be compensated or in order to facilitate shape adaptation to the shape of the battery cell. For this purpose, a higher proportion of a softener can be added to the bonding resin system of the layer composed of carbon fiber composite material, such as a monofunctional siloxane or an epoxy-treated oleic acid ester, which imparts a higher flexibility to the composite material.

[0044] According to a special design of the temperature control module, at least one heat-conducting layer composed of a unidirectional carbon fiber composite material can be arranged on each inner side of the two main surfaces, and an intermediate layer is arranged between the heat-conducting layers composed of a unidirectional carbon fiber composite material, the intermediate layer having one or more flow channels, and the two guide channels are connected to each other via the flow channels.

[0045] The intermediate layer can be made of a polymer material or a metal. For example, a polymer material as described above for the housing can be used. It is particularly advantageous if the material used for the intermediate layer is thermally conductive. For example, a thermally conductive plastic or a metal with good thermal conductivity can be used.

[0046] Particularly suitable metals are silver (429), copper (380) or aluminum (236) due to their very good thermal conductivity, respectively at 0° C. Copper is particularly preferred due to its good price / performance ratio.

[0047] Thermally conductive plastics, also referred to as thermally conductive plastic compounds, contain fillers that improve the thermal conductivity. The fillers are usually introduced into the plastic in large quantities, so that highly filled plastic compounds are mentioned. Thermally conductive highly filled plastic compounds have a filler content of at least 50% by weight. Preferably, the thermally conductive plastic compound has a thermal conductivity of at least 0.5 W / mK to 3 W / mK or even more.

[0048] Fillers for heat-conducting plastic compounds are organic fillers such as graphite, metal fillers such as copper or aluminum and ceramic fillers such as boron nitride, aluminum silicate. The quantitative proportion of fillers that improve thermal conductivity is usually at least 50% by weight, preferably at least 65% by weight and particularly preferably up to 80% by weight and more if necessary.

[0049] The thermally conductive plastic compound may contain one or more additional fillers in addition to the main filler component.

[0050] Polymer materials form the matrix of plastic compounds. Many different polymer classes can be used, such as thermoplastic polymers, thermoplastic elastomers, elastomers or thermosets.

[0051] The flow channel provided in the intermediate layer connects two guide channels which extend along two opposite edge regions of the module.

[0052] The flow channels can extend transversely via the intermediate layer from one edge region to the opposite edge region. The flow channels can be oriented parallel to each other, in particular parallel to the transverse axis. The flow channels can extend in a serpentine shape, as a corrugation or in another suitable shape.

[0053] A connecting channel may be provided which connects two or more flow channels to one another.

[0054] The flow channel can be a groove-shaped notch on one or both surface sides of the intermediate layer, and the groove-shaped notch does not completely cut the intermediate layer. If groove-shaped flow channels are provided on both surface sides, the flow channel on one surface side can be arranged staggered with the flow channel on the other surface side.

[0055] The production of the groove-shaped recesses in the surface of the intermediate layer can be carried out mechanically in a manner known per se, by embossing, milling, by means of pressing or the like.

[0056] For example, a thermoplastic, highly filled plastic compound can be used to produce the intermediate layer having the groove-shaped through-flow section.

[0057] According to a design, the flow channel can completely interrupt the intermediate layer, thereby dividing the intermediate layer into individual segments. Here, the opposite sides of two adjacent segments constitute the sides of the channel defined by the spacing between the two segments.

[0058] As sections of the intermediate layer for forming flow channels which completely cut through the intermediate layer, strips of the above-mentioned material with good thermal conductivity can be used, for example, which are arranged one behind the other and at a distance from one another in the module.

[0059] The free surface of the flow channel is covered and thus the flow channel is closed at the top or bottom by adjacent layers, for example the inside of a main surface of the housing or other inner layers of the module, for example one or more layers of unidirectional carbon fiber composite material.

[0060] The intermediate layer consisting of the heat-conducting material helps to conduct the heat from the unit to the heat transfer medium. In addition, the heat-conducting material ensures a good heat distribution at the height of the temperature control module.

[0061] The thickness of the intermediate layer is usually 0.1 mm to 0.5 mm, preferably 0.2 mm to 0.3 mm, and the width is 0.1 mm to ≥10 mm. The depth of the flow channel that completely cuts off the intermediate layer corresponds to the thickness of the intermediate layer. The depth of the grooved flow channel and the width of the flow channel (cut or grooved) are determined according to the thickness of the intermediate layer and the application. It goes without saying that the thickness and width of the intermediate layer or the depth of the flow channel can be varied as required.

[0062] The layer structure for a particularly preferred embodiment of the temperature module according to the invention thus results in the following in cross section:

[0063] - housing (including edge area with guide channel)

[0064] -Unidirectional carbon fiber composite layer

[0065] - An intermediate layer with flow channels, preferably made of a material with good thermal conductivity

[0066] -Unidirectional carbon fiber composite layer

[0067] - housing (including edge region with guide channel).

[0068] The outer shell can be cast around the other layers / coatings by means of conventional casting methods, and the edge regions with the guide channels can be cast at the same time. The heat transfer medium can be liquid or gaseous. Liquid media are preferred due to better heat transfer.

[0069] According to an advantageous embodiment, a gradient is generated on the surface of the temperature control module with respect to the cooling power. This means that a correspondingly higher cooling power can be achieved in areas with a higher thermal load than in areas with a lower thermal load. As already mentioned, the area of ​​the electrode contacts is subject to a particularly high thermal load and heat release. By providing a temperature control gradient, heat can be released very effectively in these areas.

[0070] Examples of means such as measures for generating a temperature gradient are listed below. The list is not exhaustive.

[0071] In order to generate the gradient, for example, a greater number of flow channels can be provided in regions with a higher heat release than in regions with less thermal load.

[0072] Materials with different thermal conductivities can be used for the intermediate layer. In this case, a material with very good thermal conductivity, such as copper, is placed in the region of maximum heat release. As the distance from the region with maximum heat release increases, a material with decreasing thermal conductivity can then be used.

[0073] The flow channels can have different diameters, with the channels having a larger diameter in the region with the greatest heat release and the diameter decreasing with increasing distance from the region with the greatest heat release, so that a higher cooling can be achieved in the region with the greatest heat release and overall a more homogenous heat distribution can be achieved over the battery cell surface. In the case of guided channels, the diameter can decrease in the direction of lower thermal loads.

[0074] In the flow channel and / or in the guide channel, a porous material can be used, the porosity of which decreases with increasing distance from the region with the greatest heat release.

[0075] Obstacles may be provided in the flow channel and / or in the guide channel, the arrangement and / or design of the obstacles being selected in such a way that the flow velocity of the heat transfer medium increases with increasing distance from the region with maximum heat release. For example, the number of obstacles may increase with increasing distance from the region with maximum heat release, thereby reducing the flow velocity.

[0076] It goes without saying that the measures for generating the temperature gradient can be combined with one another.

[0077] An alternative or additional possibility for generating a gradient in cooling power is cooling fins arranged on the inner wall of the flow channel, which extend into the flow channel. In order to grade the cooling power, the fins can be mounted on the inner wall at different intervals and / or in different numbers.

[0078] The cooling fins can be manufactured in different ways, for example by electrolytic separation, etching from thin foil, stamping, etc.

[0079] The fins increase the surface area that can flow around, thereby improving the homogenization of the temperature distribution in the heat transfer medium. At the same time, the fins can also be used to adjust the flow resistance of the heat transfer medium.

[0080] In particular, for use in guide channels, measures such as reducing the diameter, providing porous materials and providing obstacles are suitable, the porosity or the number of obstacles decreasing in the direction of the area with the lower thermal load.

[0081] According to a design, the connection contacts of the opposite poles of the battery cells can be directly cooled together using the temperature control module. For this purpose, a cooling tab made of a heat-conducting material is pulled out from the temperature control module, and the cooling tab can be directly connected to the cell contacts.

[0082] Advantageously, in order to form one or more cooling webs, corresponding shaped parts can be pulled out of the terminal section of the intermediate layer composed of heat-conducting material.

[0083] The cooling tabs act as heat sinks that enable direct cooling of the connection contacts, which generally constitutes the most effective method for unit cooling. The cooling tabs release heat directly to the heat transfer medium within the temperature control module via contact with the carbon fiber composite material layer and the heat transfer medium.

[0084] In order to avoid a short circuit between two connecting contacts of opposite polarity when cooling lugs are provided, the carbon fiber composite material layer must be electrically isolated from the cell contacts. For electrical isolation, insulating interruptions made of electrically insulating material can be provided in the carbon fiber composite material layer.

[0085] The carbon fiber composite material layer is divided into two parts electrically insulated from one another by means of the electrically insulating interruption.

[0086] The position of the interruption in electrical insulation depends on the position of the electrical contacts of the battery cell: ie whether 1) one contact is located on opposite sides or 2) both contacts are located side by side on the same side of the battery cell.

[0087] In the first case, the electrically insulating interruption is oriented centrally in the carbon fiber composite material layer transversely to the connection axis between the electrical contacts and in the second case centrally parallel to the electrical contacts. In both cases, the carbon fiber composite material layer is divided into parts that are electrically insulated from one another. The carbon fiber composite material layer is usually divided into two halves.

[0088] The interruption of the electrical insulation can be achieved, for example, by inserting a separator strip made of an electrically insulating material into the carbon fiber composite material layer, which separator strip divides the carbon fiber composite material layer into two parts. Since the carbon fiber composite material layer is constructed from a row of fiber layers, for this purpose, for example, the fibers of each fiber layer can be cut short to a sufficient length along the dividing surface and the resulting empty space can be filled with insulating material.

[0089] The electrically insulating material used for the interruption may be a glass fiber composite material or another suitable electrically insulating material.

[0090] The thickness of the electrical interruption depends on the thickness of the carbon fiber composite material layer and can be between 0.1 mm and 0.5 mm, preferably between 0.2 mm and 0.3 mm.

[0091] For operation, the guide channels of the temperature control module are connected to a superordinate cooling and heating system, with which the temperature of the heat transfer medium can be controlled in accordance with the operating and environmental conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] The invention is explained in more detail below using exemplary embodiments with reference to the accompanying drawings. Figures 1 to 6 An embodiment of a temperature control module according to the invention is shown for use in flat cells, for example prismatic cells or bag cells. Figure 7 An application example for a cylindrical unit is shown.

[0093] In the attached figure:

[0094] Figure 1 An embodiment of a temperature control module according to the invention is shown having an essentially plate-shaped rectangular basic shape with two opposite main surfaces having two long sides and two short sides;

[0095] Figure 2 A view showing a further embodiment of a temperature control module according to the invention in longitudinal section, two temperature control modules being placed on both sides against a flat battery cell;

[0096] Figure 3 Shown in accordance with Figure 2 A longitudinal section view of a temperature control module, which is arranged on the surface of the bag unit;

[0097] Figure 4 Shown parallel to Figure 3 A top view of a cross section of a surface of a temperature control module;

[0098] Figure 5 Shown perpendicular to Figure 4 a view of a cut-away position A on the surface of

[0099] Figure 6 Shown parallel to Figures 2 to 5 A top view of a cross section of a surface of a temperature control module having additional cooling fins;

[0100] Figure 7 A cell group consisting of cylindrical cells is shown, which has a temperature control module according to the invention adapted to the cylindrical shape; and

[0101] Figures 8 to 12 Different possibilities for staging the heat dissipation in a temperature control module according to the invention are shown. DETAILED DESCRIPTION

[0102] exist Figure 1 , a top view of a section parallel to the surface of a temperature control module having a plate-shaped rectangular basic shape is shown. Figure 1 The temperature control module is designed for use with flat battery cells, the electrode contacts 6 of which are located on the same battery side and project beyond the left short side of the module in the figure.

[0103] The edge regions of the housing 1 along the long sides and the guide channels 3 located on the edge regions can be seen, which extend along the long sides between the two short sides. At least one layer of unidirectional carbon fiber composite material 2 is arranged between the edge regions. The carbon fibers extend parallel to the long sides from the short side with the electrode contacts 6 to the opposite short side (on the right in the figure).

[0104] Each guide channel 3 has at the end on the short sides an inlet opening 4 and an outlet opening 5 for the heat transfer medium. The inlet opening 4 is located on the same short side, i.e., on the short side on which the electrode contact 6 is provided in the case of use, and the outlet openings 5 ​​are located on the opposite short side.

[0105] The flow path of the heat transfer medium in the guide channel 3 is indicated by the orientation of the arrows extending in the guide channel 3. The high heat load generated in the electrode contact area can be effectively discharged to the opposite, cooler end by the good heat transfer medium entering there and by means of the parallel-oriented carbon fibers, so that the heat load can be distributed essentially evenly over the entire unit surface.

[0106] exist Figure 2 , a longitudinal section through an arrangement of two temperature control modules is shown, each of which rests on a main surface of a bag unit. In this embodiment, the module has two layers of unidirectional carbon fiber composite material 2, between which an intermediate layer 7 with flow channels 8 is arranged. One, several or all of the flow channels 8 can be connected to a guide channel 3, which extends along the long sides in the edge region of the main surface.

[0107] The intermediate layer 7 is preferably made of a heat-conducting material, such as a metal, for example copper. However, the intermediate layer can also be made of any other suitable material, for example a heat-conducting plastic compound.

[0108] As already mentioned, the flow channel 8 can completely interrupt the intermediate layer 7 , whereby individual sections 10 of the intermediate layer 7 are obtained and the distances between adjacent sections 10 define the flow channel 8 .

[0109] Preferably, sections 10 made of heat-conducting material are provided on the two short sides (ends) of the temperature control module, from which sections are pulled out webs as cooling webs 11, which are in contact with the electrode contacts 6 of the battery cells 9 (here, for example, bag cells). The cooling webs 11 serve as heat sinks for directly cooling the electrode contacts 6.

[0110] In order to prevent the cooling fins 11 from electrically short-circuiting the two oppositely polarized electrode contacts 6 via contact with the carbon fiber composite material layer 2 and the heat transfer medium inside the temperature control module, the carbon fiber composite material layer 2 can be electrically insulated from the electrode contacts 6 by means of corresponding interruptions. For this purpose, an electrically insulating interruption 12 can be provided in the carbon fiber composite material layer 2, which extends transversely over the entire width of the carbon fiber composite material layer 2. The electrically insulating material for the interruption 12 can be a glass fiber composite material. The electrically insulating interruption 12 can extend in a strip shape between the carbon fiber composite material layer 2 and a section 10. The interruption can also be an integrated component of the carbon fiber composite material layer 2.

[0111] If Figure 2 and Figure 5 As can be seen, in the main surface of the temperature control module which bears against the battery cell 9 during use, a recess or cavity 13 can be provided on the outside, which corresponds to the length and width dimensions of the cell body and can fix the cell body or the cell stack ( Figure 5 ) is carried in.

[0112] exist Figure 3 , a longitudinal section of a temperature control module is shown, which is arranged on a bag unit. It can be seen that the preferably heat-conducting sections 10 are arranged at a distance from each other, and cooling tabs 11 for directly cooling the electrode contacts 6 are pulled out from the sections 10 at the ends on the short sides of the temperature control module. Correspondingly, an electrical interrupter 12 is installed in the carbon fiber composite material layer 2 to avoid short circuits of the two oppositely polarized electrode contacts 6. Figure 3 The edge region with the guide channel 3 can be seen on the rear long side.

[0113] In parallel by following Figure 3 A top view of a section of an intermediate layer 7 with a flow channel 8 or a section 10 of a temperature control module according to the invention is shown in FIG. Figure 4 . The guide channel 3 can be clearly seen, which extends along the two long sides of the temperature control module. The guide channel 3 (upper in the figure) has a fluid inlet opening 4 and the opposite guide channel 3 has a fluid outlet opening 5, which are arranged on opposite short sides of the module. At the end opposite the inlet or outlet opening 4, 5, the guide channel 3 is closed.

[0114] The intermediate layer 7 can be formed by strip-shaped, preferably heat-conducting sections 10, which are arranged horizontally and transversely on the module surface from the guide channel 3 with the inlet opening 4 to the guide channel 3 with the outlet opening 5. Between adjacent sections 10 there are defined flow channels 8 for the heat transfer medium.

[0115] The heat-conducting sections 10 at the ends have cooling webs 11 which protrude from the module and act as heat sinks for the electrode contacts 6 of the battery cells 9. Correspondingly, electrical interruptions 12 are provided in the module, here on both sides of the central section 10, in order to electrically insulate the opposing electrode contacts 6 from one another.

[0116] exist Figure 5 In the figure, it is shown that the Figure 4 . A battery arrangement with two battery cells 9 is shown, which are in contact with two temperature control modules. The battery cell 9 is arranged here between the two temperature control modules. The second battery cell 9 is in contact with the free second main surface of the temperature control module on the left with one main surface. The edge areas of the housing 1 with the guide channels 3 and the depressions / recesses 13 of the housing 1 extending on the outside between the edge areas, which are used to hold the battery cells 9, can be clearly seen. On the inner side of the housing 1, a layer of carbon fiber composite material 2 is respectively provided, which extends along the main surface of the temperature control module and between two opposite edge areas of the housing 1. The middle layer is a cross-section of the flow channel 8 of the middle layer 7.

[0117] It goes without saying that the battery arrangement as a battery stack or battery pack can be designed with a desired number of battery cells 9 having temperature control modules arranged between them, against which the free main surfaces of the terminal battery cells can also rest.

[0118] Figure 6 As a cross-sectional view parallel to the surface of the temperature control module, Figure 2 and Figure 5 . In this design, a certain number of cooling fins 14 are located on the side of the strip-shaped section 10 of the intermediate layer 7, and the cooling fins extend into the flow channel 8. The cooling fins 14 cause an increase in the surface of the strip-shaped section 10 and thus a better heat transfer. As shown here, the fins 14 can be arranged offset from each other on two opposite sides of adjacent heat-conducting strip-shaped sections 10 and can extend into the region of the gap between two adjacent fins 14 on the opposite sides of the strip-shaped section 10.

[0119] It goes without saying that the number and arrangement of the cooling fins 14 can be changed as required.

[0120] To electrically insulate the opposite short sides with cooling webs 11, ie in use the locations of the electrode contacts 6 of the opposite poles of the battery cells 9, electrical interruptions 12 are provided which extend transversely over the entire width between the guide channels 3 of the module.

[0121] Figures 1 to 6 The embodiment and use of the temperature control module according to the invention for flat battery cells, such as pouch cells, are shown. However, the temperature control module according to the invention can also be used for temperature control of battery cells having a structure other than flat, such as for example for cylindrical cells, as in Figure 7 Here, the functions are the same.

[0122] If necessary, the flexibility of the module can be increased for such applications so that its shape can be better adapted to the curved surface of a cylindrical battery cell. For this purpose, for example, a higher proportion of a softener can be added to the bonding resin system of the layer of carbon fiber composite material 2, which softener imparts a higher flexibility to the composite material. Examples are monofunctional siloxanes or epoxidized oleic acid esters. In principle, however, the layer of carbon fiber composite material 2 can also be pressed into the desired corrugation under pressure and temperature by means of a corresponding corrugated die in a press.

[0123] As already described above, it may be desirable to grade the heat dissipation, for example to compensate for temperature drops in the battery cells 9. In this case, a higher heat dissipation may be provided in areas with a particularly high thermal load than in areas with a lower thermal load. An example of measures for achieving graded heat dissipation is schematically shown in Figures 8 to 12 Shown in. Figures 8 to 12 In each case, a top view of a section parallel to the surface of the temperature control module according to the invention is shown. Figure 2 and Figure 7 In the embodiment shown in FIG. 1 , the cooling fins 11 are located on the same short side of the module. Figures 2 to 7 In the module shown in FIG. 1 , the guide channels 3 each have a fluid inlet opening 4 on a short side and a fluid outlet opening 5 on an opposite short side, and in both guide channels 3 , the inlet opening 4 and the outlet opening 5 are each located on the same short side of the module.

[0124] The fluid inlet opening 4 is located on the short side with the cooling web 11 and therefore on the side where the electrode contacts 6 of the battery cell 9 are located when the temperature control module is mounted on the battery cell 9. This is appropriate because the highest thermal loads occur in the region of the electrode contacts 6.

[0125] If already combined Figure 1 As described, heat conduction can be caused by providing a layer of unidirectional carbon fiber composite material 2, which extends from the side with electrode contacts 6 to the opposite short side of the module. Thus, heat can be dissipated from the most thermally loaded area with electrode contacts 6 to the less thermally loaded area.

[0126] According to another possibility for heat dissipation and heat homogenization on the unit surface, the number of flow channels 8 can be varied over the length extension of the module, such as in Figure 8 Thus, the number of flow channels 8 can be in the area with the highest thermal load (in Figure 8 in the area on the left) than in the area with a smaller heat load.

[0127] In the case of the heat-conducting strips 10 defining the flow channels 8, materials with different thermal conductivities can be used (see Fig. 9 ). Thus, in areas with high thermal loads, materials with higher thermal conductivity can be used than in areas with low thermal loads. For example, a very good thermal conductor, such as copper, can be placed at the location with the greatest thermal load, i.e. at the Fig. 9 The heat conducting strip 10 is placed on the side with the electrode contacts and is covered here by the cooling web 11. As the distance from this region increases, a material with decreasing thermal conductivity, such as aluminum or the like, can be used for the heat conducting strip 10.

[0128] The gradient of heat dissipation can be achieved by different diameters of the flow channel 8, such as in Fig.10 . In this case, the diameter of the flow channel 8 decreases with increasing distance from the area with the highest thermal load. The cooling power is therefore higher in the area with flow channels 8 having a large / larger diameter and decreases with the diameter, in order to achieve a higher cooling in the more thermally loaded areas and to obtain a homogenization of the heat distribution or thermal load over the length extension of the module.

[0129] exist Fig.10 In FIG. 1 , the reduction in the diameter of the flow channel 8 from the side with the electrode contacts 6 to the opposite side is graphically illustrated by the row of circles with decreasing diameters shown on the temperature control module.

[0130] A porous material 13 can be arranged in the guide channel 3 and / or the flow channel 8 , the porosity of which decreases with increasing distance from the region of greatest thermal load.

[0131] By way of example, a longitudinal section of a guide channel 3 with a porous material 15 is shown in FIG. Fig.11 The region with the highest porosity is Fig.11 In the left side. This is the area with the highest thermal load here. The porosity decreases continuously in the direction of the opposite right short side. If the porous material 15 is arranged in the flow channel 8, it is suitable that the porosity in the flow channel decreases in the direction of the area with greater thermal load in the direction of the area with less thermal load.

[0132] As in Fig.12As shown in FIG. 1 , an obstacle 16 for adjusting the flow velocity of the heat transfer fluid can be provided in the channel, especially in the guide channel 3. Fig.12 As shown in , the number of obstacles 16 and thus the obstruction to the flow is smallest in the region with the highest heat release (here at the left end) and increases in the direction of the region with the lowest heat release (to the right in the figure).

[0133] If obstacles are located in the flow channel 8 , the obstruction to the flow in the flow channel 8 , ie the number of obstacles 16 , is greater in areas with greater thermal load than in areas with less thermal load.

[0134] The flow velocity of the heat transfer medium can also be adjusted by selecting the shape and / or size of the obstacles.

[0135] The reduction or grading of the heat transfer can also result in a reduction in the number of cooling fins 14 .

[0136] It goes without saying that a combination of the measures shown above for adjusting the temperature gradient via the temperature control module is also possible. The measures for adjusting the flow rate can be, for example, as in Fig.11 and Fig.12 As shown in FIG. 1 , in combination with one or more further measures, such as providing a layer of unidirectional carbon fiber composite material ( Figure 1 ), different spacings of flow channels are provided ( Fig.10 ), provided with materials for heat-conducting strips 10 having different thermal conductivities ( Fig. 9 ) and / or reduce the Fig.10 The diameter of the flow channel 7.

[0137] For batteries having electrode contacts 6 on opposite sides, such as for example Figures 2 to 6 As in the case of heat conduction, the measures for Figures 8 to 12 As described in the embodiments of the present invention, it is oriented in a suitable manner towards the center of the module.

[0138] According to the invention, a multi-functional temperature control module for cooling and heating rechargeable battery cells, in particular lithium-ion battery cells, is provided, which ensures reliable operation in an ideal temperature range between 15° C. and 35° C., enables uniform distribution of the heat load over the entire battery surface, efficient heat removal from particularly thermally loaded areas, such as the area of ​​the electrode contacts, and graded heat removal with particularly high heat removal performance in particularly thermally loaded areas. In addition, the temperature control module can be designed for different battery types and shapes.

[0139] Reference numerals list

[0140] 1 Shell

[0141] 2 layers of unidirectional carbon fiber composite material

[0142] 3 Guide Channel

[0143] 4 Inlet opening for heat transfer medium

[0144] 5. Discharge opening for heat transfer medium

[0145] 6-pole contact

[0146] 7 Middle Layer

[0147] 8 flow channels

[0148] 9 Battery Cells

[0149] 10 strips, especially heat-conducting strips (sections)

[0150] 11Cooling tabs

[0151] 12 Electrical insulation interruption

[0152] 13 Recessed portion / recess in housing 1

[0153] 14 Cooling fins

[0154] 15Porous materials

[0155] 16 Obstacles for adjusting flow velocity.

Claims

1. Thermostatic modules for heating or cooling battery cells, in, The temperature control module comprises a housing (1) made of a polymer material, and the housing (1) has two opposite main surfaces, the two main surfaces are connected to each other along their edges, and the housing (1) surrounds the components of the temperature control module located inside. At least one heat-conducting layer made of a unidirectional carbon fiber composite material (2) is arranged inside the temperature control module, and a guide channel (3) extends on two opposite edge regions of the two main surfaces respectively for conveying a heat transfer medium. The at least one heat-conducting layer made of a unidirectional carbon fiber composite material (2) extends between the guide channels (3) on the module surface, and The carbon fibers of the carbon fiber composite material (2) are oriented parallel to electrode contacts (6) of a battery cell to be temperature-controlled in order to dissipate heat from the contact region of the battery cell.

2. The temperature control module according to claim 1, in, A layer composed of a unidirectional carbon fiber composite material (2) is arranged on the inner side of each of the two main surfaces of the shell (1), and an intermediate layer (7) is arranged between the layers composed of the unidirectional carbon fiber composite material (2), the intermediate layer having one or more flow channels (8), and the guide channels (3) are connected via the flow channels.

3. The temperature control module according to claim 2, in, The intermediate layer (7) is made of heat-conducting material.

4. The temperature control module according to claim 3, in, The heat conductive material used for the intermediate layer (7) is metal.

5. The temperature control module according to claim 3, in, The thermally conductive material used for the intermediate layer (7) is a thermally conductive plastic compound.

6. The temperature control module according to claim 5, in, The thermally conductive plastic compound has a thermal conductivity of at least 0.5 W / mK.

7. The temperature control module according to claim 2 or 3, in, The one or more flow channels (8) divide the intermediate layer (7) into individual sections (10) separated from one another.

8. The temperature control module according to claim 2 or 3, in, The one or more flow channels (8) are groove-shaped recesses in the intermediate layer.

9. The temperature control module according to claim 2 or 3, in, Cooling fins (14) are installed on the side walls of the flow channel (8).

10. The temperature control module according to any one of claims 1 to 6, in, Recesses (13) are provided on the outer sides of the two main surfaces for holding the battery cells.

11. The temperature control module according to claim 2 or 3, in, The flow channels (8) extend parallel to each other between the guide channels (3) along a transverse axis of the temperature control module.

12. The temperature control module according to claim 7, in, Measures are provided for grading the heat dissipation.

13. The temperature control module according to claim 12, wherein: The measures are selected as follows: a) the number of flow channels (8) decreases along the temperature drop, b) the thermal conductivity of the material used for said section (10) decreases along the temperature drop, c) the diameter of the flow channel (8) and / or the guide channel (3) decreases along the temperature drop, d) inserting a porous material (15) into the guide channel (3) and / or the flow channel (8), wherein the porosity decreases as the temperature drops, e) inserting obstacles (16) into the guide channel (3) and / or the flow channel (8), the number of the obstacles (16) increasing along the temperature drop, and f) Combining two or more of the above measures a) to e).

14. The temperature control module according to any one of claims 1 to 6, in, Cooling fins (11) for directly cooling electrode contacts (6) of adjacent battery cells (9) are provided at least on the end sides of the temperature control module.

15. The temperature control module according to any one of claims 1 to 6, in, The polymer material used for the housing (1) is an elastomer.

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