Temperature control system for a lithium-ion battery cell

Abstract

The present 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 an outer shell (1) made of a polymer material surrounding at least one heat-conducting layer made of a unidirectional carbon fiber composite material (2), and two opposing edge regions of its main surfaces each have a conducting conduit (3) for conducting a heat-conducting medium, wherein the conducting conduit (3) extends from one end to the other along the edge region, and preferably at least two one-above-the-other layers made of the unidirectional carbon fiber composite material (2) are provided, with an intermediate layer (7) between the layers having a flow conduit (8) connecting the conducting conduits (3) to each other.

Description

Technical Field

[0001] The present invention relates to an effective temperature control system for cooling and heating a rechargeable battery cell, particularly a rechargeable lithium (Li) ion battery (LIB).

[0002] LIBs have a high energy density relative to their weight and required space. Therefore, they are already used in many application fields for effectively storing energy. Particularly prominent examples of applications are as an energy source in electromobility, for example in electric vehicles and so-called hybrid vehicles.

[0003] Typically, for operation, a plurality of battery cells are integrated into one battery module, or two or more battery modules are integrated into one battery pack. These cells and / or modules may be connected in series and / or in parallel.

[0004] There are battery cells of various sizes and shapes, such as cylindrical cells, prismatic cells, or flat cells such as pouch cells (coffee bag cells). In pouch cells, a flexible housing is used, which usually consists of an aluminum film coated with plastic on both sides. The typical dimensions of a pouch cell are 350 mm × 100 mm. Flat cells such as pouch cells and prismatic cells are advantageous from the viewpoints of better thermal conductivity and stackability.

[0005] The typical structure of an LIB is as follows. That is, starting from the anode side, - an anode having a current collector (usually copper) coated with an active material (usually graphite) on at least the side facing the cathode, - a separator for electronically separating the electrodes, but through which Li ions can permeate, - a cathode having a current collector (usually aluminum) coated with an active material that releases lithium ions during charging of the cell on at least the anode side, - It includes an electrolyte (usually liquid or solid) that functions as a mediator between the reactions at the electrodes and ensures Li-ion transport.

[0006] Suitable materials for the active substances of the cathode or anode, separator, and electrolyte are in the prior art.

[0007] For the operability and safety of LIBs, as well as for all other types of rechargeable batteries, the central importance lies in maintaining a specified temperature range. Thermal management of rechargeable battery cells is an important criterion to ensure normal operation with optimal output and service life.

[0008] Generally, it is important to operate lithium-ion battery cells within a defined temperature range between 15 °C and 35 °C to avoid premature aging of the battery cells and ensure high cycle stability. Only when the battery system operates consistently within the ideal temperature range can it achieve up to 1600 full-cycle charges over a 10-year service life required by the industry. Therefore, a battery system whose storage capacity is lost by 20% compared to its state at the time of shipment (Begin of Life, BoL), and as a result, can only use a maximum of 80% of the original cell capacity when fully charged (State of Health, SoH), can no longer be used for automotive applications (End of Life, EoL).

[0009] Regardless of the season, whether in summer or winter, it is necessary to ensure that the cells can operate within a constant temperature range of 15 °C to 35 °C through appropriate temperature control of the battery cells, where the optimal operating temperature is under 25 °C. For example, if the battery operates continuously at 40 °C, the aging will accelerate up to 50%.

[0010] It is necessary to take into account that the thermal behavior of the battery cell has strong anisotropy. In the case of a polyethylene film, in the direction perpendicular to the cell surface, the slight thermal conductivity of about 1 W / mK of the separator determines the thermal conductivity of the cell stack or the wound cell roll in a cylindrical cell. In the plane of a pouch cell or a prismatic cell or in the height direction of a cylindrical cell, the thermal conductivity is determined by the current collector made of metal, which is about 30 W / mK.

[0011] A further problem is caused by the desire of the driver of an electric vehicle to keep the charging cycle at the charging station as short as possible. In the near future, a charging system with a supply voltage of 800 V will already appear, and it will be possible to achieve a high charging rate (C-rate) from 3C to 5C. Such a high C-rate leads to an increase in the current line density around the contact area of the electrode and ultimately leads to a rapid heating of the entire cell.

[0012] In any case, temperatures above 80 °C must be avoided. Because in this range, the electrolyte layer around the graphite particles of the anode deteriorates. Generally, temperatures above 60 °C should be avoided. In this regard, in warm countries, it is necessary to take into account that the ambient temperature and the heat radiation from the road surface may lead to such high heating.

[0013] A further important aspect that accelerates the aging of the cell is, in addition to the absolute operating temperature, the temperature uniformity across the cell surface and the cell thickness. As seen across the cell surface, a temperature gradient occurs there, and the temperature here is maximum in the region of the electrode contact. Such different thermal distributions lead to mechanical stresses inside the cell that can shorten the service life.

[0014] The large charge and discharge currents, which are current issues, increase the current line density in the electrode terminal contact region, leading to an increase in heating in this region. This ultimately causes mechanical stress in the anode or cathode coating, which on the one hand can directly damage the anode particles in particular, and on the other hand can lead to a loss of electrical contact between the particles based on expansion and contraction, and ultimately can also lead to the peeling of the coating from the current collector film and the associated loss of electrical contact between the coating and the current collector. Therefore, it is necessary to release the heat from the electrode contact region and consider a heat distribution that is as uniform as possible across the cell surface or cell thickness.

[0015] In the thermal management of battery systems, it is also necessary to take into account the operation of the vehicle at low temperatures. At low temperatures, especially below 0 °C, the cell voltage drops extremely. Since the cell voltage is already insufficient for normal operation at temperatures below 10 °C, the driving range of the vehicle is significantly limited.

[0016] The operating voltage of LIBs is typically in the range of 2.7 V to 4.2 V. Based on the increase in electrolyte viscosity with decreasing temperature, its ionic conductivity and the associated cell voltage also decrease. Since the lower cut-off voltage of the cell is reached at about 2.7 V, further operation of the cell is not possible for safety reasons.

[0017] Also, when charging the battery cell at low temperatures, in addition to a decrease in battery capacity, there is also a possibility of so-called lithium plating (Li-Plating) on the anode. This lithium plating (Li-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 moves the ions from the cathode to the anode, where the ions are inserted (intercalated) into the lattice structure of the active material (e.g., graphite).

[0018] Especially at low temperatures, instead of lithium ions being deposited on the anode in a desirable form, metallic lithium is formed, and this metallic lithium accumulates on the anode, thereby potentially rendering it no longer usable for the charging process. Such a loss of cyclable lithium ions degrades the performance of the battery and, in the worst case, can lead to so-called "Thermal Runaway" involving cell ignition and explosion.

[0019] From the above, 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 necessary. Therefore, a temperature control module that can effectively enable both cooling and heating functions is desirable. For this purpose, the temperature control module should have as good a thermal contact as possible with the surface of the battery cells.

[0020] Therefore, a suitable temperature control module should have the following characteristics. That is, - Structurally, it should be as slim and lightweight as possible. - Mechanically, it should be self-supporting but have a certain degree of flexibility with respect to torsion and bending. - It needs to be flowable for temperature control by a liquid or gaseous heat transfer medium. - Preferably, the module should be able to compensate for temperature non-uniformity (temperature gradient) across the battery cell surface. - It should have an elastically deformable surface layer for better bonding with the uneven surface and an even distribution of the pressure load on the anode layer of the battery stack. - It should have a certain degree of mechanical flexibility to accommodate possible dimensional changes of the cells during charging / discharging, especially in the case of pouch cells. - The cell contacts of the battery cells should be able to be directly cooled or heated.

[0021] This problem is solved by a temperature control module according to the present invention for cooling or heating a battery cell. Here, the temperature control module has an outer shell made of a polymer material, and this outer shell includes two opposite main surfaces whose edges are connected to each other, and conduction pipelines for a heat transfer medium extending along the edges are provided in two opposite edge regions of the main surfaces respectively. Here, at least one heat conduction layer made of a unidirectional carbon fiber composite material is provided inside the module, and this heat conduction layer extends across the module surface between the conduction pipelines.

[0022] The thickness of the temperature control module should be made as thin as possible so as not to unnecessarily increase the required space of the battery system equipped with the temperature control module. Therefore, a flat temperature control module is desired, and its thickness is thin compared to other dimensions such as the length, width, or diameter of the temperature control module. The shape of the temperature control module follows the shape of the battery cell used. A rectangular basic shape is reasonable for flat battery cells. However, other shapes such as square and circular are also possible.

[0023] The outer shell surrounds the internal components of the module. This outer shell has two opposite main surfaces that are connected to each other along its edges. This connection can be made through the side surfaces.

[0024] The outer shell having an edge region is formed of at least a partially flexible polymer material such as silicone elastomer or polyurethane elastomer. The partially flexible polymer material preferably has a Shore hardness A of A20 to A60, or a Shore hardness 00 of 0020 to 0080. For example, for a battery cell or a battery cell stack having a structured and undulating surface, a more flexible polymer material that can be easily adapted to the surface structure of the battery can be used for the outer shell, so that good contact between the temperature control module and the battery cell surface can be ensured. Good contact between the temperature control module and the battery cell is desirable for as effective heat transfer as possible.

[0025] In addition to compensating for the undulations on the surface of the battery cell, this outer shell causes uniform pressure transmission to the cell. For example, a pressure of 0.1 to 0.5 MPa can be reliably transmitted, and complete restoration can be guaranteed when the pressure is released. Therefore, this outer shell can act against the dimensional changes during charging / discharging and can stabilize the anode and cathode coatings of the current collector.

[0026] Along two opposite edge regions of the main surface, one conduction pipeline for conducting a heat transfer medium extends respectively. These conduction pipelines can each have an inlet opening and an outlet opening for the heat transfer medium. If these conduction pipelines are connected to each other, one conduction pipeline can have an inlet opening and the other conduction pipeline can have an outlet opening.

[0027] A connection part to a cooling / heating system is provided at the inlet opening, and here, these connection parts can be directly molded on the outer shell.

[0028] Between the main surfaces of the outer shell, at least one heat conduction layer made of a unidirectional carbon fiber composite material exists. The layer made of this unidirectional carbon fiber composite material is excellent due to its high thermal conductivity in the fiber direction. Therefore, these fibers are oriented parallel to the cell contacts of the battery cells to be temperature-controlled so as to distribute and integrate heat across the cell surface.

[0029] Due to the parallel orientation of the fibers, heat is released particularly from the contact regions of the cells that are thermally loaded. As a result, the contact regions are released from the thermal load, the heat is uniformly distributed across the entire plane, and overall cooling of the entire plane is obtained. Moreover, the layer made of the carbon fiber composite material is used as a partially flexible support structure for further module components.

[0030] This layer made of the carbon fiber composite material may be formed from a unidirectional web made of carbon fibers in a thermosetting or thermoplastic matrix.

[0031] Typically, the carbon fiber web may be composed of several layers of carbon fibers.

[0032] The thickness of the layer made of the 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 made of the carbon fiber composite material may be formed from a unidirectional web of carbon fibers in a silicone resin matrix.

[0033] If necessary, for example, the flexibility of the carbon fiber composite material layer can be increased when it is necessary to compensate for the non-uniformity of the surface of the battery cell or to facilitate the shape adaptation to the battery cell shape. For this purpose, plasticizers such as monofunctional siloxanes or epoxidized oleic acid esters that give the composite material higher flexibility can be added to the binding resin system of the layer made of the carbon fiber composite material at a higher ratio.

[0034] According to a special embodiment of the temperature control module, at least one heat conduction layer made of a unidirectional carbon fiber composite material may be provided on the inner side of each of the two main surfaces, and there is an intermediate layer having one or more flow-through pipes connecting the two conduction pipes to each other between these heat conduction layers made of the unidirectional carbon fiber composite material.

[0035] This intermediate layer may be made of a polymer material or a metal. For example, the polymer material can be used as described above for the outer shell. It is particularly advantageous when the material for the intermediate layer is thermally conductive. For example, a thermally conductive plastic or a metal having a good thermal conductivity can be used.

[0036] Based on their very good thermal conductivities at 0 °C respectively, particularly suitable metals are silver (429), copper (380), or aluminum (236). Based on a good price-performance ratio, copper is particularly advantageous.

[0037] Thermally conductive plastics, also referred to as thermally conductive plastic compounds, contain fillers that improve thermal conductivity. Since this filler is usually contained in large amounts in plastics, here, a plastic compound filled at a high concentration will be described. The filler content of a thermally conductive plastic compound filled at a high concentration is 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 more.

[0038] The fillers of thermally conductive plastic compounds are organic fillers such as graphite, metal fillers such as copper or aluminum, and ceramic fillers such as boron nitride and aluminum silicate. The content of the filler that improves thermal conductivity is generally at least 50% by weight, preferably at least 65% by weight, particularly preferably up to 80% by weight, and more as required.

[0039] In addition to the main filler component, the thermally conductive plastic compound can include one or more additional fillers.

[0040] The polymer material forms the matrix of the plastic compound. Various types of polymers can be used, such as thermoplastic polymers, thermoplastic elastomers, elastomers, or thermosetting resins.

[0041] The flow-through pipelines provided in the intermediate layer connect two conduction pipelines extending along two opposite edge regions of the module.

[0042] These flow-through pipelines can extend from one edge region to the opposite edge region so as to cross the intermediate layer. They may be oriented parallel to each other, particularly parallel to the horizontal axis. They can extend in a meandering line shape, a winding shape, or other suitable shapes.

[0043] Connection pipelines connecting two or more flow-through pipelines may be provided.

[0044] These flow-through pipelines may be groove-shaped cuts on one or both sides of the intermediate layer, where the groove-shaped cuts do not completely divide the intermediate layer. When groove-shaped flow-through pipelines are provided on both sides, the flow-through pipeline on one side may be arranged offset from the flow-through pipeline on the other side.

[0045] The generation of the groove-shaped cuts on the surface of the intermediate layer can be mechanically performed in a manner known per se, such as by embossing, milling, extrusion, etc.

[0046] For example, a thermoplastic plastic compound filled at a high concentration can be used for manufacturing an intermediate layer with a groove-shaped flow.

[0047] According to one embodiment, the flow-through pipeline can completely divide the intermediate layer, whereby the intermediate layer is divided into individual sections. Here, the opposite side surfaces of two adjacent sections form the side surfaces of the pipeline defined by the distance between the two sections.

[0048] As sections for forming an intermediate layer having a flow-through pipeline that completely divides the intermediate layer, for example, strips made of a good heat-conductive material as described above can be used, and these are arranged spaced apart from each other in sequence within the module.

[0049] The coating of the exposed surface of the flow-through pipeline and the accompanying closure upward or downward of the flow-through pipeline form adjacent layers, for example, inside the main surface of the outer shell, or further inner layers of the module, such as a single layer or multiple layers made of, for example, a unidirectional carbon fiber composite material.

[0050] The intermediate layer made of a heat-conductive material contributes to releasing the heat coming from the cell to the heat transfer medium. Furthermore, the heat-conductive material ensures a good heat distribution over the height of the temperature control module.

[0051] The thickness of the intermediate layer is generally from 0.1 mm to 0.5 mm, preferably from 0.2 mm to 0.3 mm, and the width is from 0.1 mm to 10 mm or less. The depth of the flow-through pipeline that completely divides the intermediate layer corresponds to the thickness of the intermediate layer. The depth of the groove-shaped flow-through pipeline and the width of the (divided or groove-shaped) flow-through pipeline are determined according to the thickness of the intermediate layer and the application. It should be understood that the thickness and width of the intermediate layer or the depth of the flow-through pipeline can be changed as required.

[0052] Therefore, the layer structure of a particularly preferred embodiment of the temperature module according to the present invention has the following cross-section, that is, - An outer shell (having an edge region with a conduction pipeline) - A unidirectional carbon fiber composite material layer - An intermediate layer having a flow-through pipeline, preferably an intermediate layer made of a material with good thermal conductivity - A unidirectional carbon fiber composite material layer - An outer shell (having an edge region with a conduction pipeline) which occurs in a cross-section consisting of

[0053] The outer shell can be cast around a further layer using a conventional casting method, where, at the same time, the edge region having the conduction pipeline can also be cast.

[0054] The heat transfer medium may be a liquid or a gas. Based on better heat transfer, a liquid medium is advantageous.

[0055] According to a preferred embodiment, a gradient in the cooling capacity is generated across the surface of the temperature control module. This means that in regions with a higher heat load, correspondingly higher cooling capacity is possible compared to regions with a lower heat load. As already mentioned, the regions of the electrode contacts are particularly exposed to high heat loads and heat generation. By providing a temperature gradient, these regions can be effectively relieved of the load.

[0056] Examples of measures such as means for generating a temperature gradient are shown below. The performance is not final.

[0057] For example, in order to generate a gradient, more flow-through pipes may be provided in a region with a relatively large amount of heat generation than in a region with a low heat load, for example.

[0058] Different thermally conductive materials can be used for the intermediate layer. In this case, a material having a very good thermal conductivity, such as copper, is arranged in the region with the maximum heat generation amount. Materials with a smaller thermal conductivity can be used as the distance from the region with the maximum heat generation amount increases.

[0059] The flow-through pipes can have different diameters. The pipes in the region with the maximum heat generation amount have a larger diameter, and the diameter decreases as the distance from the region with the maximum heat generation amount increases. Thus, in the region with the maximum heat generation amount, higher cooling and overall uniformization of the heat distribution across the battery cell surface can be obtained. In the case of conduction pipes, the diameter can be made smaller in the direction where the heat load is lower.

[0060] In the flow-through pipes and / or conduction pipes, a porous material can be used, and its porosity decreases as the distance from the region with the maximum heat generation amount increases.

[0061] In the flow-through pipes and / or conduction pipes, obstacles may be provided, and their arrangement and / or configuration are selected such that the flow velocity of the heat transfer medium increases as the distance from the region with the maximum heat generation amount increases. For example, the number of obstacles can be increased as the distance from the region with the maximum heat generation amount increases, thereby reducing the flow rate.

[0062] It should be understood that the means for generating the temperature gradient can be combined with each other.

[0063] Alternative or additional means for generating a gradient of cooling capacity consists in providing cooling fins on the inner wall of the flow-through conduit protruding into the flow-through conduit. For a stepwise change in cooling capacity, these fins may be attached to the inner wall at various lengths of distance and / or in various numbers.

[0064] The cooling fins can be manufactured by various techniques, for example, electrodeposition, etching removal from a thin film, stamping, etc.

[0065] These fins increase the surface that can be flowed around, thereby improving the homogenization of the temperature distribution in the heat transfer medium. At the same time, they can also be used to adjust the flow rate of the heat transfer medium.

[0066] In particular, for use in a conduction conduit, means such as reducing the diameter, providing a porous material, and providing obstacles are suitable. In this case, the number of pores or obstacles is reduced in the direction of the region with a lower heat load.

[0067] According to one embodiment, by using a temperature control module, the reverse-polarity connection contact of the battery cell can be directly cooled. For this purpose, a cooling tab made of a thermally conductive material is drawn out from the temperature control module, and this cooling tab can be directly connected to the cell contact.

[0068] Preferably, corresponding shaped parts can be drawn out from the end section of the intermediate layer made of a thermally conductive material to form one or more cooling tabs.

[0069] These cooling tabs are used as heat sinks enabling direct cooling of the connection contacts, which generally represents the most effective method of cell cooling. These cooling tabs directly release heat to the heat transfer medium through contact with the carbon fiber composite material layer and the heat transfer medium within the temperature control module.

[0070] When a cooling tab is provided, the carbon fiber composite material layer must be electrically insulated from the cell contacts in order to avoid a short circuit between two connection contacts of opposite polarities. For this electrical insulation, an insulating barrier made of an electrically insulating material may be provided in the carbon fiber composite material layer.

[0071] By using the electrically insulating barrier, the carbon fiber composite material layer is separated into two electrically insulated portions.

[0072] The position of the electrically insulating barrier is adjusted according to the position of the electrical contacts of the battery cell. That is, it is adjusted according to whether 1) there is one contact on each of the opposite sides, or 2) two contacts are adjacent to each other on the same side of the battery cell.

[0073] In the former case, the electrically insulating barrier in the carbon fiber composite material layer is oriented transversely to the connection axis between the electrical contacts at the center, and in the latter case, it is oriented parallel to the electrical contacts at the center. In both cases, the carbon fiber composite material layer is divided into portions that are electrically insulated from each other. Usually, the carbon fiber composite material layer is separated into two halves.

[0074] The electrically insulating barrier can be made, for example, by inserting a separation strip made of an electrically insulating material into the carbon fiber composite material layer, which separates the carbon fiber composite material layer into two parts. Since the carbon fiber composite material layer is formed from a series of fiber layers, for example, the fibers of each fiber layer are shortened to a sufficient length along the separation plane, and the resulting empty space can be filled with an insulating material.

[0075] The electrically insulating material for the barrier may be a glass fiber composite material or other suitable electrically insulating material.

[0076] The thickness of the electrical barrier can be 0.1 mm to 0.5 mm, preferably 0.2 mm to 0.3 mm, in the direction of the thickness of the carbon fiber composite material layer.

[0077] For operation, the conduction pipeline of the temperature control module is connected to the upper heating and cooling system, whereby the heat transfer medium can be temperature-controlled according to the operating conditions and the ambient conditions.

[0078] Hereinafter, the present invention will be described in more detail based on embodiments with reference to the drawings. FIGS. 1 to 6 show embodiments of the temperature control module according to the present invention for use in flat cells such as prismatic cells or pouch cells. FIG. 7 shows a usage form for a cylindrical cell.

Brief Description of the Drawings

[0079]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

[0080] FIG. 1 shows a plan view of a cross section parallel to the surface of a temperature control module having a plate-shaped rectangular basic shape. The temperature control module according to FIG. 1 is designed for use with flat battery cells, and its electrode contacts 6 are present on the same side of the battery and project beyond the left short side of the module in the figure.

[0081] The edge region of the outer shell 1 along the long side and the conduction pipe 3 existing in the edge region extending along the long side between the two short sides can be visually recognized. At least one layer made of a unidirectional carbon fiber composite material 2 is arranged between these edge regions. The carbon fibers extend parallel from the short side having the electrode contact 6 along the long side to the opposite short side (right side in the figure).

[0082] Each conduction pipe 3 has an inlet opening 4 and an outlet opening 5 for the heat transfer medium at the end of the short side, respectively. The inlet opening 4 is on the same short side, that is, the short side where the electrode contact 6 exists during application, and the outlet opening 5 is on the opposite short side, respectively.

[0083] The flow path of the heat transfer medium in the conduction pipe 3 is shown by the orientation of the arrows extending in the conduction pipe 3. The high heat load generated in the electrode contact region can be effectively released to the relatively cooler end by using the carbon fibers oriented parallel to the fresh heat transfer medium flowing in there, so that this heat load can be distributed substantially uniformly over the entire cell surface.

[0084] Figure 2 shows a longitudinal cross-section through an array of two temperature control modules in contact with the main surface of the pouch-shaped cell 9. In this embodiment, the module has two layers made of unidirectional carbon fiber composite material 2, between which there is an intermediate layer 7 having a flow-through conduit 8. One or more of the flow-through conduits 8 or all of the flow-through conduits 8 can be connected to a conduction conduit 3 extending along the long side within the edge region of the main surface.

[0085] The intermediate layer 7 preferably consists of a thermally conductive material such as a metal, for example copper. However, it can also be manufactured from other suitable materials such as thermally conductive plastic compounds.

[0086] As already mentioned, the flow-through conduit 8 can completely divide the intermediate layer 7, thereby obtaining separate sections 10 of the intermediate layer 7, and the distance between adjacent sections 10 defines the flow-through conduit 8.

[0087] Preferably, there are sections 10 made of a thermally conductive material at the two short sides (ends) of the temperature control module, from which tabs are drawn out as cooling tabs 11 that contact the electrode contacts 6 of the battery cell 9 (here, for example, a pouch-shaped cell). These cooling tabs 11 are used as heat sinks for directly cooling the electrode contacts 6.

[0088] To avoid the cooling tabs 11 in the temperature control module electrically short-circuiting the two electrodes of opposite polarities 6 through contact with the carbon fiber composite material layer 2 and the heat transfer medium, the carbon fiber composite material layer 2 can be electrically insulated from the electrode contacts 6 using corresponding cut-off parts. For this purpose, the carbon fiber composite material layer 2 may be provided with an electrical insulation cut-off part 12 extending across the entire width of the carbon fiber composite material layer 2. The electrical insulation material for this cut-off part 12 may be a glass fiber composite material. This electrical insulation cut-off part 12 can extend in a strip shape between the carbon fiber composite material layer 2 and the section 10. This electrical insulation cut-off part may be an integral component of the carbon fiber composite material layer 2.

[0089] As is apparent from FIGS. 2 and 5, on the outside of the main surface of the temperature control module that abuts against the battery cell 9 during application, a recess or depression 13 may be provided that corresponds to the length and width dimensions of the cell body 9 and can fix the cell body 9 or support it in a cell stack (FIG. 5) (FIG. 5).

[0090] FIG. 3 shows a longitudinal cross-sectional view of a temperature control module disposed on a pouch-shaped cell 9. In order to visually recognize the thermally conductive sections 10, which are preferably spaced apart from each other, here, cooling tabs 11 for directly cooling the contacts 6 are drawn out from the end sections 10 on the short sides of the temperature control module, respectively. Correspondingly, in order to avoid a short circuit between two electrodes of opposite polarities 6, an electrical cutoff section 12 is incorporated into the carbon fiber composite material layer 2. On the longitudinal side of the temperature control module behind FIG. 3, an edge region having a conduction conduit 3 can be visually recognized.

[0091] FIG. 4 shows a plan view of a cross-section passing parallel to an intermediate layer 7 having a flow conduit 8 or section 10 of the temperature control module according to the present invention according to FIG. 3. Therein, the conduction conduits 3 extending along the two long sides of the temperature control module can be clearly visually recognized. One conduction conduit 3 (above in the figure) has a fluid inlet opening 4, and the opposing conduction conduit 3 has a fluid outlet opening 5. In this case, these inlets 4 and outlets 5 are arranged on the opposing short sides of the module. The conduction conduits 3 are connected to the ends opposite to the inlet opening 4 and the outlet opening 5.

[0092] The intermediate layer 7 may be formed of strip-shaped, preferably thermally conductive sections 10, arranged to horizontally cross the module surface from the conduction conduit 3 having the inlet 4 to the conduction conduit 3 having the outlet 5. The distance between adjacent sections 10 defines a flow conduit 8 for the heat transfer medium.

[0093] The heat-conductive section 10 at the end protrudes from the module and has a cooling tab 11 that functions as a heat sink for the electrical contact 6 of the battery cell 9. Correspondingly, within the module, there are electrical cutoff portions 12 arranged on both sides of the central section 10 here to electrically insulate the opposing electrode contacts 6 from each other.

[0094] FIG. 5 shows a cross-sectional view of the cutting position A perpendicular to the surface according to FIG. 4. Here, a battery array having two battery cells 9 in contact with two temperature control modules is shown. The battery cells 9 are arranged here between the two temperature control modules. The second battery cell 9 has one main surface in contact with the exposed second main surface of the temperature control module on the left side. Here, the edge region of the outer shell 1 having the conduction pipeline 3, as well as the depression / recess 13 of the outer shell 1 used for holding the battery cell 9 extending between the outer edge regions, can be clearly visually recognized. Inside the outer shell 1, there are layers made of carbon fiber composite material 2 respectively, and this layer extends between the two opposing edge regions of the outer shell 1 along the main surface of the temperature control module. The intermediate layer is a cut section passing through the flow-through pipeline 8 of the intermediate layer 7.

[0095] It should be understood that the battery array can be designed as a battery stack or battery pack having a desired number of battery cells 9 with temperature control modules arranged therebetween, in which case the exposed main surface of the end battery cell can also be in contact with the temperature control module.

[0096] Figure 6 shows a cross-sectional view parallel to the surface of a temperature control module as shown in Figures 2 and 5. In this embodiment, a plurality of cooling fins 14 protruding into the flow-through pipe 8 are present on the side surfaces of the strip-shaped section 10 of the intermediate layer 7. These cooling fins 14 cause an increase in the surface of the strip-shaped section 10, thereby resulting in better heat transfer. As shown here, these fins 14 may be arranged offset from each other on two opposite side surfaces of adjacent thermally conductive strip-shaped sections 10 and can extend into the gap region between two adjacent fins 14 on the opposite side surfaces of the strip-shaped section 10.

[0097] It should be understood that the number and arrangement of the cooling fins 14 can be changed as needed.

[0098] An electrical cutoff 12 is provided for electrical insulation of the opposite short sides having the cooling tabs 11, i.e., for positioning the electrodes 6 of the opposite polarity of the battery cell 9 during application. This electrical cutoff 12 extends across the entire width between the conduction pipes 3 of the module.

[0099] Figures 1 to 6 show the configuration and use of the temperature control module according to the present invention for flat battery cells such as pouch cells. However, the temperature control module according to the present invention can also be used for temperature control of battery cells having a shape different from the flat configuration, such as the cylindrical cell shown in Figure 7. In that case, the functionality is the same.

[0100] If necessary, the flexibility of the module can be increased for this application, thereby enabling the shape of the module to be well adapted to the curved surface of the cylindrical battery cell. For example, for this purpose, a higher proportion of plasticizer that gives the composite material higher flexibility can be added to the binding resin system of the layer made of the carbon fiber composite material 2. Examples include monofunctional siloxane or epoxidized oleic acid ester. However, basically, the layer made of the carbon fiber composite material 2 can also be press-processed into a desired waveform by pressing under pressure and temperature using a corresponding corrugated press mold.

[0101] As already described above, for example, when it is desirable to stepwise control heat dissipation to compensate for the temperature gradient within the battery cell 9, higher heat dissipation may be assumed in regions with particularly high heat loads than in regions with lower heat loads. Examples of means for realizing the stepwise control of heat dissipation are schematically shown in FIGS. 8 to 12.

[0102] FIGS. 8 to 12 each show a plan view of a cross-section parallel to the surface of the temperature control module according to the present invention. Different from the embodiments shown in FIGS. 2 and 7, in the embodiment shown here, a plurality of cooling tabs 11 are present on the same short side of the module. Alternatively to the module shown in FIGS. 2 to 7, each of the conduction pipelines 3 has a fluid inlet opening 4 on one short side and a fluid outlet opening 5 on the opposite short side, and in this case, for both conduction pipelines 3, the inlet 4 and the outlet 5 are present on the same short side of the module respectively.

[0103] The fluid inlet opening 4 is present on the short side having the cooling tab 11, and thus on the side where the electrode contact 6 of the battery cell 9 is present for the purpose of use when attaching the temperature control module to the battery cell 9. This is reasonable because the maximum heat load occurs in the region of the electrode contact 6.

[0104] As already described in connection with FIG. 1, heat conduction can be caused by providing a layer made of unidirectional carbon fiber composite material 2, in which case the carbon fibers extend from the side having the electrode contact 6 to the opposite short side of the module. Thus, heat can be released from the region with the highest heat load having the electrode contact 6 to the region with a lower heat load.

[0105] According to a further means for heat release and heat homogenization across the cell surface, the number of flow-through channels 8 can be varied along the longitudinal extension direction of the module as shown in FIG. 8. Thereby, the number of flow-through channels 8 in the region with the highest heat load (left side in FIG. 8) may be greater than that in the region with a lower heat load.

[0106] When the heat-conductive strip 10 defines the flow-through channels 8, materials with different thermal conductivities can be used (see FIG. 9). Thus, in the region with a high heat load, a material with a higher thermal conductivity than that in the region with a lower heat load can be used. For example, a very good heat conductor, such as copper, can be arranged at the location with the highest heat load, i.e., on the side having the electrode contact covered by the cooling tab 11 here in FIG. 9. For the heat-conductive strip 10, a material with a decreasing thermal conductivity as the distance from this region increases, such as aluminum, can be used.

[0107] The gradient of heat release can be realized by different diameters of the flow-through channels 8 as shown in FIG. 10. Here, the diameter of the flow-through channels 8 decreases as the distance from the region with the highest heat load increases. Thus, the cooling capacity is higher in the region with a higher heat load to obtain a higher cooling effect, and in order to maintain the heat distribution or the homogenization of the heat load along the longitudinal extension direction of the module, it becomes higher in the region having the flow-through channels 8 with a large / larger diameter and decreases with the diameter.

[0108] In FIG. 10, the decrease in the diameter of the flow-through channels 8 from the side having the electrode contact 6 to the opposite side is shown by the row of circles with decreasing diameters shown above the temperature control module.

[0109] The conduction line 3 and / or the flow line 8 may be provided with a porous material 13, and the porosity thereof decreases as the distance from the region most thermally loaded increases.

[0110] An example of the longitudinal cross-section of the conduction line 3 having the porous material 15 is shown in FIG. 11. The region with the maximum porosity 15 is on the left side of FIG. 11. This is the region with the maximum thermal load here. This porosity 15 gradually decreases in the direction of the opposite right short side. If the porous material 15 is provided in the flow line 8, it is reasonable that the porosity 15 in the flow line in the region with a strong thermal load decreases in the direction of the region with a low thermal load.

[0111] As shown in FIG. 12, the pipeline, particularly the conduction line 3, may be provided with obstacles 16 for adjusting the flow rate of the heat transfer fluid. As shown in FIG. 12, the number of obstacles 16, and thus the number of inhibitions to the flow, is minimized in the region with the maximum heat generation amount (here the left end), and increases in the direction towards the region with the minimum heat generation amount (the right side of the figure).

[0112] When the obstacle is present in the flow line 8, the inhibition of the flow in the region with a higher thermal load, that is, the number of obstacles 16 in the flow line 8, should be more than that in the region with a lower thermal load.

[0113] The adjustment of the flow rate of the heat transfer medium can also be carried out by selecting the shape and / or size of the obstacle.

[0114] The reduction or stepwise reduction of heat transfer can also be obtained by reducing the number of cooling fins 14.

[0115] It should also be understood here that a combination of the above-described means for adjusting the temperature gradient across the temperature control module is possible. For example, the means for adjusting the flow-through as shown in FIGS. 11 and 12 can be combined with one or more additional means such as providing a layer made of a unidirectional carbon fiber composite material (FIG. 1), providing different distances of the flow-through conduits (FIG. 10), providing materials for the heat-conductive strips 6 having different thermal conductivities (FIG. 9), and / or reducing the diameter of the flow-through conduit 8 according to FIG. 10.

[0116] For example, in the case of a battery having electrode contacts 6 on opposite sides as shown in FIGS. 2 to 6, the heat dissipation means as described in the embodiments according to FIGS. 8 to 12 is reasonably oriented towards the center of the module.

[0117] According to the present invention, a variety of temperature control modules for cooling and heating rechargeable battery cells, particularly lithium-ion battery cells, are provided, which can ensure safe operation in an ideal temperature range between 15°C and 35°C, uniform distribution of the heat load across the entire battery surface, effective release of heat from particularly heat-loaded regions such as the regions of the electrode contacts, and stepped heat release with particularly high release capacity in particularly heat-loaded regions. Further, this temperature control module can be designed according to different battery types and different forms.

Description of the reference numerals

[0118] 1 Outer shell 2 Layer made of a unidirectional carbon fiber composite material 3 Conductive conduit 4 Inlet opening for the heat transfer medium 5 Outlet opening for the heat transfer medium 6 Electrode contact 7 Intermediate layer 8 Flow-through conduit 9 Battery cell 10 Strip, particularly a heat-conductive strip (section) 11 Cooling tab 12 Electric insulation barrier 13 Depression / recess in the outer shell 1 14 Cooling fins 15 Porous material 16 Obstacle for adjusting the flow-through velocity

Claims

1. A temperature control module for cooling or heating a battery cell, wherein the temperature control module includes a housing (1) made of a polymer material, the housing (1) has two opposite main surfaces whose edges are interconnected, and the housing (1) surrounds the internal components of the temperature control module, at least one heat conduction layer made of a unidirectional carbon fiber composite material is provided inside the temperature control module, and one conduction pipeline (3) for conducting a heat transfer medium extends in each of two opposite edge regions of the main surface, the at least one heat conduction layer made of the unidirectional carbon fiber composite material (2) extends across the module surface between the conduction pipelines (3), the carbon fibers of the unidirectional carbon fiber composite material (2) are oriented parallel to the conduction pipelines (3). Temperature control module.

2. A layer made of a unidirectional carbon fiber composite material (2) is provided inside each of the two main surfaces of the housing (1), and an intermediate layer (7) having one or more flow-through pipelines (8) connecting the conduction pipelines (3) exists between the layers made of the unidirectional carbon fiber composite material (2). The temperature control module according to claim 1.

3. The intermediate layer (7) is made of a heat conductive material. The temperature control module according to claim 2.

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

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

6. The heat conductive plastic compound has a thermal conductivity of 0.5 W / mK. The temperature control module according to claim 5.

7. One or more flow-through pipelines (8) divide the intermediate layer (7) into mutually separated individual sections (10). The temperature control module according to any one of claims 2 to 6.

8. The one or more flow-through pipelines (8) are groove-shaped cuts in the intermediate layer. The temperature control module according to any one of claims 2 to 6.

9. Cooling fins (14) are provided on the side walls of the flow-through pipeline (8). The temperature control module according to any one of claims 2 to 6.

10. The temperature control module according to any one of claims 1 to 9, wherein a recess (13) for holding a battery cell is provided outside the two main surfaces.

11. The temperature control module according to any one of claims 2 to 9 or claim 10 which cites claim 2, wherein the flow-through pipelines (8) extend parallel to each other along the horizontal axis of the temperature control module between the conduction pipelines (3).

12. The temperature control module according to any one of claims 1 to 11, wherein means for staging heat dissipation is provided.

13. Said means are the following means, namely: a) means for reducing the number of the flow-through pipelines (8) along a temperature gradient; b) means for reducing the thermal conductivity of the material for the individual sections / strips (7 / 10) obtained by separating the intermediate layer (7) from each other along a temperature gradient; c) means for reducing the diameter of the flow-through pipelines (8) and / or the conduction pipelines (3) along a temperature gradient; d) means for inserting a porous material (13) into the conduction pipelines (3) and / or the flow-through pipelines (8) and reducing the porosity along a temperature gradient; e) means for inserting obstacles (16) into the conduction pipelines (3) and / or the flow-through pipelines (8) and increasing the number of the obstacles (16) along a temperature gradient; f) means for combining two or more of said means a) to e); The temperature control module according to claim 12 which cites claim 2, selected from the above.

14. The temperature control module according to any one of claims 1 to 13, wherein a cooling tab (11) for directly cooling the electrode contacts (6) of adjacent battery cells (9) is provided on at least one end face of the temperature control module.

15. The temperature control module according to any one of claims 1 to 14, wherein the polymeric material for the outer shell (1) is an elastomer.

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