Battery module and battery system having a heat exchanger housing

Abstract

A battery module is provided that includes a liquid-tight housing and a plurality of battery cells disposed within the liquid-tight housing. A first temperature regulating fluid is contained within the liquid-tight housing in thermal contact with the plurality of battery cells and an inner surface of the liquid-tight housing. The liquid-tight housing is configured to allow a flow of a second temperature regulating fluid between an inner surface and an outer surface of the liquid-tight housing. A battery system is further provided that includes the battery module and a secondary temperature regulating system connected to the liquid-tight housing of the battery module and configured to establish a flow of the second temperature regulating fluid.

Description

[Technical Field]

[0001] The present invention relates to a battery module and a battery system that enable efficient and uniform temperature regulation of battery cells. [Background technology]

[0002] In light of the anticipated limited availability of traditional fuels and the increasing levels of air pollution from engine exhaust, attention has recently been focused on alternative propulsion solutions. Regardless of the primary energy source, most approaches require battery modules and systems with high power density, long life, and high performance.

[0003] Building a battery system involves mechanically, electrically, and thermally integrating multiple battery cells into a working unit. Additional aspects to consider are the chemical compatibility of the components used, safety features in case of thermal runaway, and ease of mass production.

[0004] Proper temperature control of each battery cell in a battery system is a critical requirement, especially when charging or discharging the battery. For example, for lithium-ion battery cells, failure to observe temperature limits can lead to a gradual degradation of battery performance and can even lead to rapid and dangerous destruction of the battery.

[0005] Conventionally, temperature control of battery cells in a battery system can be achieved indirectly, for example, by providing a cooling body in thermal contact with the base of a cylindrical battery cell. A flow of a temperature-regulating fluid is established through channels contained in the cooling body. In this way, heat generated by the battery cell is transferred to the cooling body through the outer shell of the battery cell. This configuration exhibits a large thermal inertia, resulting in high temperature peaks under heavy loads or during charging. These temperature peaks can be prevented by limiting the maximum current. However, conventional systems do not tolerate sudden load changes.

[0006] Alternatively, the battery cells can be cooled directly via a temperature-regulating fluid in direct thermal contact with the battery cells. For this purpose, liquid-tight hollow spaces can be provided around the outer shell of the battery cells. By passing the temperature-regulating fluid through these hollow spaces, heat generated primarily at the poles of the battery cells is transferred through the outer shell to the temperature-regulating fluid. This technique is known as immersion cooling. The disadvantage of such a system is that each hollow space around the outer shell of the battery cells requires a liquid-tight seal, usually at two locations on the outer shell of the battery cells.

[0007] In more advanced systems, the battery cells are completely immersed in the temperature-regulating fluid. This configuration requires a large amount of temperature-regulating fluid, which increases the weight and cost of the system. Furthermore, the temperature-regulating fluid must exhibit specific properties because it is in contact not only with the outer shell of the battery cells but also with the electrodes. Summary of the Invention [Problem to be solved by the invention]

[0008] In view of the above, it would be desirable to provide improved battery modules and systems that allow for efficient and uniform temperature regulation of battery cells. [Means for solving the problem]

[0009] This is achieved by the features of the independent claims. The dependent claims describe advantageous embodiments.

[0010] The present invention relates to a battery module including a liquid-tight housing and a plurality of battery cells disposed within the liquid-tight housing. The battery module further includes a first temperature-regulating fluid contained within the liquid-tight housing in thermal contact with the plurality of battery cells and an inner surface of the liquid-tight housing. The liquid-tight housing is configured to allow the flow of a second temperature-regulating fluid between the inner and outer surfaces of the liquid-tight housing.

[0011] In other words, the battery module comprises a plurality of battery cells in a housing. The housing is liquid-tight, i.e., the first temperature-regulating fluid contained in the housing cannot escape to the outside of the housing. However, the liquid-tight housing may comprise openings, for example, for electrical feedthroughs or signal lines. Furthermore, the liquid-tight housing may comprise openings connecting the interior of the liquid-tight housing to channels, tubes, pipes, etc. for the first temperature-regulating fluid. However, these openings (feed-through openings, fluid connection openings) are sealed against the ambient environment.

[0012] Each battery cell is in thermal contact with a first temperature-regulating fluid. In particular, the temperature-regulating fluid can cover the polar portions of each battery cell, since heat is primarily generated in the polar portions. Furthermore, the first temperature-regulating fluid is in thermal contact with the inner surface of the housing. For example, the first temperature-regulating fluid can be in contact with the entire inner surface of the housing or a portion of the entire inner surface of the housing. Thus, heat generated by the battery cells can be transferred to the housing via the first temperature-regulating fluid. This can be achieved, for example, by conduction or convection. A flow of a second temperature-regulating fluid can be established within the housing, i.e., between the inner and outer surfaces of the housing, for example, by a secondary temperature-regulating system. For this purpose, the housing can be configured to allow the flow of the second temperature-regulating fluid. For example, the wall of the housing can have an internal hollow space for the flow of the second temperature-regulating fluid. In other words, the wall portions of the liquid-tight housing can be configured to allow the second temperature-regulating fluid to flow through these wall portions. In particular, the wall portion arranged to allow the second temperature-regulating fluid to flow may correspond to an inner surface (or part thereof) of the liquid-tight housing that is in thermal contact with the first temperature-regulating fluid within the liquid-tight housing.

[0013] In this configuration, the liquid-tight housing of the battery module can function as a heat exchanger between an internal primary temperature-regulating system, e.g., a first temperature-regulating fluid contained in the housing, and an external secondary temperature-regulating system, particularly a second temperature-regulating fluid flowing through the housing wall. Because the second temperature-regulating fluid does not contact the battery cells, the requirements for the properties of this second temperature-regulating fluid are lower. In particular, the second temperature-regulating fluid does not necessarily need to be an insulator. Furthermore, the battery module is a separate, compact unit with an integrated heat exchanger connected to the secondary temperature-regulating system.

[0014] The liquid-tight housing allows multiple thermally independent battery modules to be electrically connected to each other to form a battery system. The multiple thermally independent battery modules can be connected to a secondary temperature regulation system, which allows for individual temperature control of each of the multiple battery modules, such that temperature differences between the modules can be minimized or intentionally induced.

[0015] Furthermore, by separating the internal primary temperature-regulating system from the secondary temperature-regulating system for each temperature-regulating fluid, it is possible to use a general second temperature-regulating fluid that does not exhibit specific electrical properties, and in particular does not necessarily need to be an insulator, since the second temperature-regulating fluid does not come into contact with the battery cells, particularly their pole portions.

[0016] In one embodiment, the battery module further includes a pump disposed outside the liquid-tight housing and connected to the interior of the liquid-tight housing through a first fluid channel of the liquid-tight housing, the pump configured to generate a flow of the first temperature-regulating fluid within the liquid-tight housing by pumping the first temperature-regulating fluid through the first fluid channel.

[0017] That is, the flow of the first temperature-conditioning fluid can be actively established inside the liquid-tight housing by the pump. The first fluid channel of the liquid-tight housing can be spatially separated from the flow of the second temperature-conditioning fluid within the walls of the liquid-tight housing. In other words, the first temperature-conditioning fluid and the second temperature-conditioning fluid do not mix with each other. The internal temperature-conditioning circle (pump, first channel, liquid-tight housing) is spatially separated from the secondary temperature-conditioning circle (external temperature-conditioning system, flow of the second temperature-conditioning fluid within the walls of the liquid-tight housing).

[0018] Within the liquid-tight housing, the flow of the first temperature-regulating fluid can be guided by a dedicated channel that may be formed, for example, by the arrangement of the battery cells relative to the housing. That is, the flow of the first temperature-regulating fluid can be determined by the specific arrangement of the battery cells rather than by a dedicated tube or pipe. In other words, the channel does not need to be formed by a dedicated physical conduit, pipe, or tube, but can be formed by the configuration of space within the liquid-tight housing that is not occupied by physical solid components such as battery cells, sensors, housing parts, holders, wires, other electrical connection means, etc.

[0019] In this configuration, the temperature uniformity within the battery module can be increased, and further, the heat transfer between the battery cells and the housing can be improved.

[0020] In one embodiment, the fluid-tight housing, the pump, and the first fluid channel form a materially closed system for the first temperature regulating fluid.

[0021] That is, the first temperature-regulating fluid is enclosed within the space provided by the liquid-tight housing, the first fluid channel, and the interior space of the pump. In other words, exchange of material (e.g., the first temperature-regulating fluid) between the internal system (e.g., the interior of the liquid-tight housing, the first fluid channel, and the interior of the pump) and the outside of the battery module is prevented, while exchange of thermal energy, i.e., heat, can occur.

[0022] In one embodiment, the fluid-tight housing comprises a second fluid channel for the flow of a second temperature-regulating fluid.

[0023] That is, the liquid-tight housing can be configured to allow the flow of a second temperature-regulating fluid between the inner surface of the liquid-tight housing and the outer surface of the liquid-tight housing by providing a second fluid channel. In other words, the second flow path is formed within the wall of the liquid-tight housing. Furthermore, the liquid-tight housing may include multiple second flow paths. The second flow paths do not fluidly communicate with the interior of the battery module, the first flow path, or the pump.

[0024] In one embodiment, the second fluid channel projects into the interior of the fluid-tight housing. That is, the inner surface of the liquid-tight housing, which is in thermal contact with the first temperature-conditioning fluid, exhibits a structured, non-flat surface. For example, the inner surface may exhibit a wavy or grooved surface. The inner surface may have grooves and ridges. For example, the paths of the second fluid channels may correspond to or match the paths of the respective ridges on the inner surface. For example, the ridges and the second fluid channels may be arranged so that the second fluid channels are located within the respective ridges. A particular advantage of an inner surface exhibiting a non-flat surface is that it increases the area of thermal contact with the first temperature-conditioning fluid. This improves the heat transfer rate between the first and second temperature-conditioning fluids through the channel walls, resulting in higher cooling / heating efficiency.

[0025] For example, the second fluid channel has a circular cross section. The cross section of the second fluid channel may be oval, rectangular, etc. Furthermore, the second fluid channel may exhibit portions with circular cross section and portions with different cross sections.

[0026] In one embodiment, the second fluid channel extends in the direction of the major axis of the battery module. The major axis of the battery module may be an axis extending in a predetermined direction relative to the housing. For example, the major axis may be a base axis of the battery module. For example, the major axis may extend in a direction corresponding to the direction of the maximum or minimum physical size of the battery module or the liquid-tight housing. For example, the major axis may extend in a direction corresponding to the direction of the highest or lowest (discrete) axis of rotational symmetry of the battery module or the liquid-tight housing. If the liquid-tight housing is substantially box-shaped, the major axis of the battery module may extend in a direction perpendicular to the side of the (notional) circumscribing box.

[0027] According to one embodiment, the liquid-tight housing includes a profiled housing, a first end plate, and a second end plate. The profiled housing has two open end faces located opposite each other along a major axis of the battery module. The first and second end plates close the profiled housing in a liquid-tight manner at the two open end faces.

[0028] The profiled housing may be a box-shaped or substantially box-shaped housing portion having two opposing open faces and four wall portions arranged to have a rectangular or substantially rectangular cross section. The main axis of the battery module may extend from the first open face to the second open face of the profiled housing. The profiled housing may include grooves and / or ridges on the outer and / or inner surfaces of one or more of the face portions. The grooves may extend in the direction of the main axis of the battery module. The first and second end plates are attached to the profiled housing to close the open faces of the profiled housing in a liquid-tight manner. This seals the interior of the battery module against leakage of the first temperature-regulating fluid at contact points or contact areas.

[0029] In one embodiment, the battery module includes a first seal disposed circumferentially between the first end plate and the profiled housing, and a second seal disposed circumferentially between the second end plate and the profiled housing.

[0030] That is, the first and second end plates can be attached to the profiled housing, with a seal being provided in the contact area between the end plates and the profiled housing, the seal extending circumferentially substantially following the cross section of the profiled housing.

[0031] For example, the first seal and the second seal are flat seals. In one embodiment, each of the first seal and the second seal is disposed in a plane perpendicular to the major axis of the battery module.

[0032] In one embodiment, the profile housing is configured as a double-walled profile housing with the second fluid channel integrally formed therein.

[0033] In other words, the profile housing comprises an outer wall and an inner wall portion with the second fluid channel integrally formed therebetween.

[0034] In one embodiment, the profile housing is made of a material having a thermal conductivity of 50 W / (m·K) or greater.

[0035] A thermal conductivity of 50 W / (m·K) or more may allow for improved heat transfer between the first and second temperature regulating fluids through the liquid-tight housing. The profile housing may be made of a material having a thermal conductivity of preferably 100 W / (m·K) or more, more preferably 150 W / (m·K) or more, more preferably 200 W / (m·K) or more, more preferably 300 W / (m·K) or more, more preferably 400 W / (m·K) or more.

[0036] For example, the profile housing is made of aluminum. The profile housing may be made of another material such as gold, silver, titanium, steel, copper, etc. For example, the profile housing may be made of metal.

[0037] In one embodiment, the first endplate and / or the second endplate are made of a synthetic material.

[0038] For example, the first end plate and / or the second end plate may be made of plastic or fiberglass reinforced plastic. For example, the first end plate and / or the second end plate may be made of another material, such as acrylonitrile-butadiene-styrene copolymer (ABS), nylon 12 (polyamide 12, PA12), etc.

[0039] In one embodiment, the liquid-tight housing is partially filled with a gas. In other words, the liquid-tight housing may not be completely filled with the first temperature regulating fluid (in addition to the physical solid components included as battery cells, connection means, etc.) but may also contain a quantity of gas, thereby allowing for changes in the volume of the first temperature regulating fluid, for example due to changes in temperature, without significantly increasing or decreasing the pressure within the liquid-tight housing.

[0040] For example, the liquid-tight housing may be partially filled with air, nitrogen, or an inert gas such as a noble gas (eg, helium, neon, argon, krypton, xenon).

[0041] For example, the volume percentage of the liquid-tight housing filled with gas is 5% or less. For example, this volume percentage may be 10% or less, 5% or less, 4% or less, 3% or less, or 1% or less. For example, the volume percentage may be a predetermined percentage or more (e.g., 0.1%, 0.2%, 1%, etc.). For example, the volume percentage may be between 0.1% and 1%, between 1% and 2%, between 2% and 3%, between 3% and 4%, between 4% and 5%, etc. The volume percentage may relate to the volume percentage relative to the total volume of the interior of the liquid-tight housing at a predetermined temperature, such as 298.15 K (25°C).

[0042] For example, the ratio of the volume of gas to the volume of the first temperature regulating fluid at a predetermined temperature may be 1% or less, 2% or less, 3% or less, 4% or less, 5% or less, 10% or less, 15% or less, etc. The ratio of the volume of gas to the volume of the first temperature regulating fluid at a predetermined temperature may be greater than a predetermined percentage (e.g., 0.1%, 0.2%, 1%, etc.).

[0043] In one embodiment, the liquid-tight housing is airtight. That is, the liquid-tight housing may be configured to prevent gas from entering or escaping the liquid-tight housing.

[0044] For example, the liquid-tight housing is gas-tight up to a positive pressure of at least 1 bar. For example, the liquid-tight housing is gas-tight up to a negative pressure of at least 1 bar.

[0045] Positive pressure is the pressure difference between the outside and the inside of the liquid-tight housing, where the pressure outside the liquid-tight housing is lower than the pressure inside the liquid-tight housing. Negative pressure is the pressure difference between the inside and the outside of the liquid-tight housing, where the pressure outside the liquid-tight housing is higher than the pressure inside the liquid-tight housing. 1 bar is 10 5 Pa and therefore corresponds approximately to normal atmospheric pressure.

[0046] For example, the liquid-tight housing may exhibit a leak rate below a predetermined threshold. -2 mbar·l / s, 10 -3 mbar·l / s, 10 -4 mbar·l / s, 10 -5 mbar·l / s, or 10 -6 It may exhibit a leak rate of up to mbar·l / s.

[0047] In one embodiment, the battery module further comprises a plurality of cell holders including half-shell portions configured to hold the plurality of battery cells, the sides of the plurality of battery cells being covered by the half-shell portions.

[0048] That is, the battery cells are held by the cell holder of the battery module, and the side surfaces of the battery cells are completely covered or covered to a significant extent (e.g., more than 95%, more than 90%). In the case of a cylindrical battery cell having a side shell and two poles located at the upper and lower bases, the half-shell portions of the cell holder have a substantially semicircular cross section. Note that the battery module is not limited thereto, and the half-shell portions may have a cross section corresponding to the shape of the battery cell. That is, for example, in the case of a non-cylindrical battery cell, the half-shell portions may be non-circular but correspond to the shape of the battery cell. Furthermore, while the shape of the inner surface of the half-shell portion that contacts the battery cell can correspond to the shape of the battery cell, the shape of the outer surface of the half-shell portion may differ from the shape of the battery. Each battery cell may be held between two half-shell portions that are in contact with each other in a mating manner. For example, the thickness of each half-shell portion may exceed a predetermined threshold.

[0049] In this configuration, the first temperature-regulating fluid can be preferentially guided along the poles of the battery cells where heat is primarily generated. Furthermore, by providing a cell holder with a specific thickness, the volume of the space for the first temperature-regulating fluid can be reduced, thereby reducing the weight of the battery module. Furthermore, heat transfer from the battery cells to the second temperature-regulating fluid via the first temperature-regulating fluid and the liquid-tight housing can be improved.

[0050] In one embodiment, each battery cell is electrically connected in parallel or series to one or more other battery cells to form a battery stack.

[0051] In other words, the plurality of battery cells can include subsets of battery cells, with the battery cells of each subset connected in parallel with each other, and further subsets of battery cells connected in series with each other, thereby forming a battery stack, with the overall voltage provided by the battery stack depending on the number of series-connected subsets and the types of battery cells used.

[0052] In one embodiment, the battery module includes an electrical feedthrough connected to the battery stack.

[0053] Electrical feedthroughs can pass through the liquid-tight housing to provide electrical connection to the battery stack. The battery module can include two electrical feedthroughs as the positive and negative terminals of the battery module.

[0054] According to another aspect, the present invention relates to a battery system comprising a battery module according to any one of the above aspects and variations thereof, and a secondary temperature-regulating system connected to the liquid-tight housing of the battery module and configured to establish a flow of a second temperature-regulating fluid.

[0055] In other words, the battery system includes a battery module including a primary temperature-conditioning system, such as a first temperature-conditioning fluid in thermal contact with the battery cells and the inner surface of a liquid-tight housing, and a secondary temperature-conditioning system. The liquid-tight housing functions as a heat exchanger for exchanging heat between the first temperature-conditioning fluid and the second temperature-conditioning fluid. Specifically, heat can be transferred from the battery cells to the first temperature-conditioning fluid and further to the second temperature-conditioning fluid through the liquid-tight housing. The heat absorbed by the second temperature-conditioning fluid can then be dissipated by a dedicated heat dissipation means of the secondary temperature-conditioning system, which can be a second heat exchanger for exchanging heat between the second temperature-conditioning fluid and a heat sink, which can be ambient air. Similarly, heat can be transferred to the battery module by heating the second temperature-conditioning fluid by a dedicated heating means of the secondary temperature-conditioning system.

[0056] In one embodiment, the first temperature regulating fluid is different from the second temperature regulating fluid. For example, the first temperature-regulating fluid may be an electrically insulating temperature-regulating fluid. The second temperature-regulating fluid does not necessarily have to be electrically insulating, since it does not come into contact with the poles and / or electrical connection means in the liquid-tight housing of the battery module. For example, the second temperature-regulating fluid may be a mixture of water and glycol.

[0057] The battery system of the present invention provides improved temperature control capabilities, uniform cooling of battery cells within the battery module, reduced weight of the battery module, and / or improved system flexibility through an internal temperature regulation system that can be thermally coupled to a secondary temperature regulation system by allowing a second temperature regulation fluid to flow between the inner and outer surfaces of the housing.

[0058] Further benefits and advantages of the present invention will become apparent from the detailed description of the embodiments and the drawings. [Brief explanation of the drawings]

[0059] [Figure 1] 1 shows an external view of a battery module. [Figure 2] 1 shows an external view of a battery module. [Figure 3] FIG. 1 is an external view of a battery module, without showing the cover. [Figure 4] 1 shows the profile housing of the battery module. [Figure 5] FIG. 1 is a cutaway view of a basic arrangement of battery cells within a battery module. [Figure 6] FIG. 1 is a cross-sectional view of the arrangement of battery cells within a profile housing. [Figure 7] 1 shows the flow of a first temperature regulating fluid within a battery module. [Figure 8] 10 illustrates the flow of a second temperature regulating fluid within the housing of the battery module. [Figure 9] 1 illustrates an exemplary electrical connection of multiple battery cells in parallel from an orientation. [Figure 10]10 illustrates an exemplary electrical connection of multiple battery cells in parallel from another perspective. [Figure 11] 10 illustrates an exemplary electrical connection of multiple battery cells in parallel from another perspective. [Figure 12] 10 illustrates an exemplary electrical connection of multiple battery cells in parallel from another perspective. [Figure 13] 1 shows electrically connected battery cells held by cell holders. [Figure 14] 1 shows electrically connected battery cells held by cell holders. [Figure 15] 1 shows two sets of parallel-connected battery cells with their respective cell holders. [Figure 16] 1 shows two sets of parallel-connected battery cells with their respective cell holders. [Figure 17] 1 shows a battery stack including multiple battery cells. [Figure 18] 1 shows a battery stack including multiple battery cells. [Figure 19] FIG. 2 is an overall view of a battery stack. [Figure 20] FIG. 2 is an overall view of a battery stack. [Figure 21] FIG. 2 is a schematic diagram of the electrical connections of the battery cells in the battery stack. [Figure 22] 1 shows the appearance of a battery module. [Figure 23] 1 shows the appearance of a battery module. DETAILED DESCRIPTION OF THE INVENTION

[0060] DESCRIPTION OF THE PREFERRED EMBODIMENT In the following, preferred embodiments will be described in detail by referring to the drawings.

[0061] 1 and 2 show external views of a battery module 100 viewed from different directions. The battery module includes a liquid-tight housing 110, which includes a first end plate 114, a profiled housing 113, and a second end plate 116. The battery module 100 also includes a pump cover 115, two electrical feedthroughs 117a, 117b, and four ports 118a-118d for connection to a secondary temperature regulation system.

[0062] The liquid-tight housing 110 has a substantial shape of a rectangular parallelepiped, with two opposite sides formed by a first end plate 114 and a second end plate 116, and the remaining four sides formed by the profiled housing 113. A pump cover 115 is disposed on the outer surface of the first end plate 114 and covers a pump 130 attached to the outside of the first end plate 114. Planar seals are provided between the first end plate 114 and the profiled housing 113, and between the second end plate 116 and the profiled housing 113, to close the housing 110 in a liquid-tight manner. The planar seals circumferentially surround the open end faces of the profiled housing 113.

[0063] The liquid-tight housing 110 contains a plurality of battery cells 120 connected together to form a battery stack, the details of which are described further below. Additionally, a first temperature-regulating fluid is contained within the liquid-tight housing 110. The first temperature-regulating fluid is preferably an insulating fluid having a high thermal conductivity.

[0064] The profiled housing 113 is substantially box-shaped and has two open sides opposite each other. The profiled housing 113 is made of aluminum and therefore exhibits high thermal conductivity. However, the material of the housing is not limited to aluminum, and the housing may be made of other materials with thermal conductivity of 50 W / (K·m) or more, preferably 100 W / (K·m) or more, more preferably 150 W / (K·m) or more, and even more preferably 200 W / (K·m) or more.

[0065] The profiled housing 113 has grooves and / or ridges on two opposing outer surfaces. However, the profiled housing 113 is not limited to having grooves and / or ridges on two opposing surfaces. The profiled housing 113 can have grooves and / or ridges on only one surface, two surfaces, three surfaces, or all four surfaces. In the battery module 100 shown in FIGS. 1 and 2 , the grooves and / or ridges extend in the direction of the major axis (y-axis) of the battery module 100. The direction of the major axis extends along the direction of the maximum physical size of the profiled housing 113.

[0066] The profile housing 113 further comprises threaded holes on the front and rear sides for attaching the first end plate 114 and the second end plate 116 in a liquid-tight manner.

[0067] The first end plate 114 and the second end plate 116 are substantially flat rectangular shapes. The substantially rectangular shapes of the first and second end plates 114, 116 correspond to the cross-sectional shape of the profiled housing 113. The first and second end plates 114, 116 include screw holes at positions corresponding to the positions of the screw holes in the profiled housing 113.

[0068] The first end plate 114 is attached to one open end surface of the profiled housing 113 by a plurality of screws inserted into the screw holes of the first end plate 114 and the corresponding screw holes of the profiled housing 113. The second end plate 116 is attached to the other open end surface of the profiled housing 113 by a plurality of screws inserted into the screw holes of the second end plate 116 and the corresponding screw holes of the profiled housing 113. The attachment of the end plates 114, 116 to the profiled housing 113 is not limited to being achieved using screws and corresponding screw holes and threaded holes, but may be achieved using different attachment means, such as bolts and nuts.

[0069] The electrical feedthroughs 117a, 117b are connected to the battery cells 120 contained inside the liquid-tight housing 110. Specifically, one of the electrical feedthroughs 117a, 117b is connected to the positive pole of a battery stack formed by the multiple battery cells 120 in the battery module 100. The other of the electrical feedthroughs 117a, 117b is connected to the negative pole of the battery stack inside the battery module 100. In other words, the voltage of the battery module 100 is accessible from the outside through the electrical feedthroughs 117a, 117b. The electrical feedthroughs 117a, 117b, which provide electrical connection to the battery cells 120, are disposed in sealed holes in the first and second end plates 114, 116, respectively. However, the electrical feedthroughs 117a, 117b may also be provided in the profile housing 113.

[0070] Each of the first and second end plates 114, 116 is provided with two ports 118a-118d for connection to a secondary temperature regulation system, details of which are provided further below.

[0071] 3 is an external view of the battery module 100, without showing the pump cover 115. The battery module 100 includes a pump 130 attached to the outer surface of the first end plate 114. The pump 130 may be a micropump connected to the interior of the liquid-tight housing 110 via the first fluid channel 111. The pump 130 is configured to pump a first temperature-regulating fluid through the first fluid channel 111. This establishes a flow of the first temperature-regulating fluid within the liquid-tight housing 110.

[0072] 4 is a diagram of the profiled housing 113. The profiled housing 113 includes a plurality of second fluid channels 112 integrally formed with the profiled housing 113 between the inner and outer surfaces of the profiled housing 113. The second fluid channels 112 have a circular cross-section and protrude into the profiled housing 113. This increases the area of contact with the first temperature-regulating fluid within the profiled housing 113, leading to an improved heat transfer rate between the first temperature-regulating fluid and the second temperature-regulating fluid within the plurality of second fluid channels 112. Because the second temperature-regulating fluid does not contact the battery cells 120, it does not need to be an insulator and can be a common temperature-regulating fluid, such as a mixture of water and glycol.

[0073] Although the profiled housing 113 shown in FIG. 4 has nine linear second fluid channels 112 extending in the direction of the major axis y of the battery module 100 on two opposing sides, the profiled housing 113 is not limited thereto. In particular, the profiled housing 113 may have a different number of second fluid channels 112. Furthermore, the second fluid channels 112 may be provided on one, two, three, or four sides of the profiled housing 113. Furthermore, the second fluid channels may be curved or serpentine. Furthermore, the cross section may be oval, rectangular, etc.

[0074] 5 is a cutaway view of the basic arrangement of battery cells 120 within a battery module 100. The battery module 100 includes a plurality of battery cells 120 within a liquid-tight housing 110. The battery cells 120 may be lithium-ion, nickel-cadmium, nickel-metal hydride, lead-acid, polymer-based, or any other type of battery cell. The battery cells 120 have a cylindrical shape with the poles of the battery cells 120 positioned on both circular faces of the battery cells 120. The battery cells 120 are positioned so that the circular faces are perpendicular to the major axis y of the battery module 100. When viewed along the y-axis, the battery cells 120 are arranged in a hexagonal pattern relative to each other.

[0075] FIG. 6 is a cross-sectional view of the arrangement of the battery cells 120 in the profiled housing 113. In the figure, the battery cells 120 and the second fluid channels 112 are shown for illustrative purposes only. The battery cells 120 are arranged in a dense hexagonal arrangement, and the distance between adjacent battery cells 120 on two opposite sides of the profiled housing 113, including the second fluid channels 112, is greater than the distance between adjacent battery cells 120 and the distance between the battery cells 120 and the inner surfaces of the other two sides of the profiled housing 113. This arrangement forms spaces 119 on both sides of the battery module 100 where no battery cells 120 are present, to guide the flow of the first temperature-regulating fluid through the liquid-tight housing 110. However, the arrangement of the battery cells 120 is not limited to a hexagonal arrangement and may be different. For example, the battery cells may be arranged according to a rectangular or square arrangement.

[0076] The first channel 111 of the first end plate 114 connects the pump 130 to the interior of the battery module 100 at a location corresponding to the location of the space 119. This configuration allows the pump 130 to establish a flow of the first temperature regulating fluid around the battery cells 120 in a parallel manner in the x-direction.

[0077] 7 shows the flow of the first temperature-regulating fluid by the thick arrows. The first temperature-regulating fluid is pumped by the pump 130 through the first fluid channel 111 into the interior of the liquid-tight housing 110 at a position corresponding to the position of the space 190. Because the space 190 has a relatively large cross-section, the resistance to flow in the y direction is relatively small, so the first temperature-regulating fluid flows around the battery cells 120 in a parallel manner in the x direction. The first temperature-regulating fluid then enters the other space 190 located on the opposite side and re-enters the pump 130 via the first fluid channel 111.

[0078] The first and second end plates 114, 116 include a second fluid channel connecting the second flow passage 112 of the profiled housing 113 to the port 118. That is, the second fluid channel 112 on one side of the profiled housing 113 merges with the second fluid channel in the end plates 114, 116 and leads to a fitting port 118 for connection to a secondary temperature conditioning system.

[0079] 8 shows the flow of the second temperature regulating fluid in this secondary temperature regulating system with thick arrows. The second temperature regulating fluid passes through port 118, the second fluid channel in the end plate, second fluid channel 112 in profile housing 113, the second fluid channel in the other end plate, and out of battery module 100 through another port 118.

[0080] 7 and 8, the flow of the first temperature regulating fluid in the space 119 is directed in a direction opposite to the flow of the second temperature regulating fluid in the second fluid channel 112 of the profiled housing 113. This optimizes thermal coupling between the first and second temperature regulating fluids.

[0081] That is, the liquid-tight housing 110 acts as a heat exchanger between a first temperature-regulating fluid sealed within the liquid-tight housing 110 (including the pump 130 and the first fluid channel 111) and a second temperature-regulating fluid of the secondary temperature-regulating system.

[0082] 9-12 show exemplary electrical connections of multiple parallel battery cells 120 viewed from various directions. The figures show eight battery cells 120 connected to each other in a parallel manner by two electrical connection bars 121. These electrical connection bars 121 are made of, for example, metal. The first connection bar 121 connects the positive poles of the battery cells 120 together. The second connection bar 121 connects the negative poles of the battery cells 120 together.

[0083] The connection bars 121 may be welded to the positive or negative pole of the battery cells 120. For example, each connection bar 121 may be laser welded to either the positive or negative pole of the battery cells 120. The connection bars 121 have terminal portions 122 for connection to a measuring device such as a voltage sensor (not shown). It goes without saying that the number of battery cells 120 connected in parallel with each other may be more or less than eight. Furthermore, the electrical connection means is not limited to bars 121, and may be a sheet or the like.

[0084] 13 and 14 show the electrically connected battery cells 120 of FIGS. 9 to 12 held by a cell holder 140. The cell holder 140 includes a plurality of half-shell portions 141 for respectively holding the plurality of battery cells 120. Specifically, the battery cells 120 are held by their sides, with the pole portions remaining uncovered. The cell holder 140 may be made of a non-conductive material, such as a synthetic material such as glass fiber reinforced plastic. The cell holder 140 may include mounting portions, such as holes for screws, for connection to the liquid-tight housing 110 and / or another cell holder 140.

[0085] The entire or substantially the entire side surface of the battery cell 120 is covered by the half-shell portions 141 of the two cell holders 140. In the figure, for the sake of explanation, only one cell holder 140 is shown. However, the side surface of the battery cell 120 is covered by the lower cell holder 140 (shown) and the upper cell holder (not shown). The half-shell portions of the lower cell holder 140 and the upper cell holder fit together to cover the side surface of the battery cell 120. The cell holder 140 is configured to reduce the volume occupied by the first temperature regulating fluid within the liquid-tight housing 110. For example, the cell holder may have a thickness greater than a predetermined threshold.

[0086] 15 and 16 show two sets of parallel-connected battery cells 120 with respective cell holders 140, where the two sets of parallel-connected battery cells are connected in series with each other.

[0087] 17 and 18 show a battery stack including multiple battery cells 120 viewed from both directions along the y-axis. Figures 19 and 20 are overall views of the battery stack. The battery cells 120 are connected to each other by connecting sheets 123a to 123d on the front and rear surfaces corresponding to the open end surfaces of the profiled material housing 113.

[0088] Specifically, on the surface corresponding to the position of the first end plate 114, as shown in Fig. 17, the positive electrodes of the upper three rows of battery cells 120 are connected to one another by a first connection sheet 123a. The first connection sheet 123a is connected to the first electrical feedthrough 117a. Furthermore, the negative electrodes of the middle three rows of battery cells 120 and the positive electrodes of the lower three rows of battery cells 120 are connected to one another by a second connection sheet 123b.

[0089] 18, on the surface corresponding to the position of the second end plate 116, the negative electrodes of the upper three rows of battery cells 120 and the positive electrodes of the central three rows of battery cells 120 are connected to each other by a third connection sheet 123c. Furthermore, the negative electrodes of the lower three rows of battery cells 120 are connected to each other by a fourth connection sheet 123d. The fourth connection sheet 123d is connected to the second electrical feedthrough 117b.

[0090] The battery module 100, and in particular the battery stack, is not limited to the above configuration. In particular, the battery cells 120 may be arranged in different ways depending on the type of the battery cells 120, the total voltage, and the performance to be achieved.

[0091] Furthermore, as mentioned above, each battery cell 120 is held by two half-shell portions 141 of a respective cell holder 140 located below and above the battery cell 120 .

[0092] FIG. 21 is a schematic diagram of the electrical connections of battery cells 120 in a battery stack. For reasons of clarity and ease of understanding, the battery stack is shown as including six layers of battery cells 120, with each layer containing nine battery cells 120 connected to each other in parallel or series. The layers are connected to each other by four connecting sheets 123a-123d. The total voltage of the battery stack is provided between two electrical feedthroughs 117a and 117b. The illustration is a simple visualization of the battery stack connection principle; therefore, the battery module 100 is not limited to the number of battery cells 120, rows, and layers shown.

[0093] 22 and 23 are diagrams showing the external appearance of the battery module 100, and the first and second end plates 114, 116 and the pump cover 115 are not shown.

[0094] When the battery module 100 is charging or supplies a large current, heat is generated inside the battery module 100, primarily at the poles of the battery cells. This heat may be transferred to the first temperature-regulating fluid, causing a change in the volume of the first temperature-regulating fluid. When the liquid-tight housing 110 is completely filled with the first temperature-regulating fluid, the pressure inside the liquid-tight housing 110 may increase. Therefore, the liquid-tight housing 110 is configured to be airtight. For example, the liquid-tight housing may be airtight up to a positive pressure of 1 bar, 1.5 bar, 2 bar, etc. Similarly, as the temperature of the first temperature-regulating fluid decreases, the pressure inside the liquid-tight housing 110 may decrease. Therefore, the liquid-tight housing is configured to be airtight down to a negative pressure of 1 bar. This can be achieved, for example, by utilizing a sufficiently thick profile housing 113 and first and second end plates 114, 116 that are airtightly connected to each other using a sufficient number of screws with appropriate seals.

[0095] To allow for volumetric changes of the first temperature-regulating fluid without excessive increase / decrease in pressure within the liquid-tight housing 110, the liquid-tight housing 110 may be partially filled with gas. For example, the gas may occupy up to 1%, 2%, 3%, 4%, 5%, etc., volume percentage of the interior of the liquid-tight housing. The volume percentage may be within a range between any two of the values. The volume percentage may exceed a predetermined value (e.g., 0.1%, 0.2%, 1%, etc.). The volume percentage may refer to the volume percentage relative to the volume of the interior of the liquid-tight housing 110 at a given temperature, such as 298.15 K (25° C.). Without being limited thereto, the gas contained in the liquid-tight housing 110 may be, for example, air.

[0096] In addition to the above-mentioned components, the battery module 100 may include one or more temperature sensors attached to the battery cells 120, the cell holder 140, the inner surface of the liquid-tight housing 110, etc., and respective temperature detection wires for providing temperature sensor signals to the outside of the battery module 100. The battery module 100 may further include one or more voltage detection wires connected to, for example, the connection bar 121 or the connection sheets 123a-123d for providing voltage signals to voltage sensors outside the battery module 100. Furthermore, the battery module 100 may include one or more current-limiting elements, such as fuses. The battery module 100 may further include a controller, such as a microprocessor, connected to the pump 130. The controller may receive a voltage signal from the voltage sensor and / or a temperature signal from the temperature sensor. The controller controls the operation of the pump 130 based on the temperature signal and / or the voltage signal, and, for example, their respective set points.

[0097] A battery system according to one embodiment includes at least one battery module 100 as described above and a secondary temperature-regulating system connected to the port 119 of the battery module 100. The temperature-regulating system may include, for example, a pump, a heat exchanger, and a fluid conduit for establishing a flow of a second temperature-regulating fluid. For example, the temperature-regulating system may be connected to multiple battery modules 100. For example, the second temperature-regulating fluid may flow through the multiple battery modules 100 in a parallel or serial manner. The heat exchanger of the temperature-regulating system may be configured to exchange heat between the second temperature-regulating fluid and a heat sink and / or heat source. The heat sink or heat source may be, for example, ambient air. Furthermore, the temperature-regulating system may include an electric heater configured to heat the second temperature-regulating fluid to enable temperature control of each battery module 100.

[0098] The concept of the battery module 100 and the battery system will be summarized below. The central idea of the battery module / system is to design the temperature regulation circuit for the battery module 100, consisting of multiple battery cells 120, as a closed system. This means that a defined liquid reservoir (first temperature regulation fluid) is enclosed together with the battery cells 120 in an assigned space (liquid-tight housing 110, pump 130, and first fluid channel 111). The first temperature regulation fluid circulates therein and dissipates heat from the poles of the battery cells. The heat is transferred to the inner wall of the profiled housing 113 via the first temperature regulation fluid, which is electrically non-conductive but has good thermal conductivity. A second fluid channel 112, configured to be connected to a secondary temperature regulation system, is contained in the profiled housing 113. The profiled housing 113 thus forms a heat exchanger in the form of a housing.

[0099] The end plates 114, 116 and the profiled housing 113 cooperate to form a closed, liquid-tight housing 110. The seal between the end plates 114, 116 and the profiled housing 113 ensures that the housing remains sealed and the first temperature regulating fluid does not leak even at overpressures of up to 1 bar.

[0100] A pump 130 (e.g., a micropump) is attached to one of the end plates 114, 116 of the liquid-tight housing 110 and directly connected to the first fluid channel 111 integrated into the end plates 114, 116 to transport the first temperature-regulating fluid within the liquid-tight housing 110 and generate circulation. This circulation assists in heat dissipation or absorption between the profiled housing 113 and the first temperature-regulating fluid. The profiled housing 113 can then dissipate heat through the integrated second fluid channel 112 with a second temperature-regulating fluid, such as a water-glycol mixture. This gives the profiled housing 113 the function of a heat exchanger, for example, for a temperature range of -50°C to 60°C. The temperature range for operation of the battery module 100 may depend on the flow point of the second temperature-regulating fluid in the second fluid channel 112.

[0101] The liquid-tight housing 110 contains individual battery cells 120 that are electrically connected to each other and held in place by structural components, namely, cell holders 140. The cell holders 140 also function to cover the sides of the individual battery cells 120. The cell holders 140 can cover approximately 50% of the sides. The cell holders 140 of the next row of battery cells 120 fit adjacent to this cell holder 140, covering additional surfaces in such a way that the sides of the battery cells 120 are bounded from the first temperature-regulating fluid all around. This reduces the space occupied by the first temperature-regulating fluid.

[0102] The liquid-tight housing 120, which represents a sealed container, is filled with a first temperature-regulating fluid to the extent that a layer of gas, e.g., air, is formed only in the upper region. This region is designed so that when the first temperature-regulating fluid expands under temperature, the volume of the enclosed air decreases by the volume of the expansion of the first temperature-regulating fluid. This results in a small increase in pressure within the system. The seal of the liquid-tight housing 110 is designed to withstand this pressure increase of approximately 0.3 bar, 1.0 bar, 1.5 bar, etc.

[0103] The liquid-tight housing 110 allows thermally independent battery modules 100 to be electrically connected to each other as desired to form a battery pack. This allows the internal circulation of the first temperature-regulating fluid within the battery modules 100 to be individually regulated, thereby reducing temperature differences between the battery modules 100. However, it is also possible to achieve a desired temperature distribution between the battery modules 100. This can be advantageous when parts of the battery system are used for special purposes, in which case thermal isolation can be achieved in addition to electrical isolation. The heat exchanger function is integrated into the liquid-tight housing 110 of the battery module 100. This saves costs and weight. Furthermore, it eliminates the need for complex and diverse seals. A common liquid (water-glycol) that does not need to have any special electrical properties can be used as the second temperature-regulating fluid in the secondary circuit.

[0104] In summary, a battery module is provided that includes a liquid-tight housing and a plurality of battery cells disposed within the liquid-tight housing. A first temperature-regulating fluid is contained within the liquid-tight housing in thermal contact with the plurality of battery cells and an inner surface of the liquid-tight housing. The liquid-tight housing is configured to allow a flow of a second temperature-regulating fluid between the inner and outer surfaces of the liquid-tight housing. A battery system is also provided that includes the battery module and a secondary temperature-regulating system connected to the liquid-tight housing of the battery module and configured to establish a flow of the second temperature-regulating fluid.

Claims

1. a liquid-tight housing (110); a plurality of battery cells (120) disposed within the liquid-tight housing (110); a first temperature regulating fluid contained within the liquid-tight housing (110) in thermal contact with the plurality of battery cells (120) and an inner surface of the liquid-tight housing (110); A battery module comprising: the liquid-tight housing (110) is configured to allow a flow of a second temperature-regulating fluid between the inner and outer surfaces of the liquid-tight housing (110); The liquid-tight housing (110) a profiled housing (113) having two open end faces located opposite each other along a major axis of the battery module; a first end plate (114) and a second end plate (116) that close the profile housing (113) fluid-tightly at the two open end faces; Equipped with The profiled housing (113) is configured as a double-walled profiled housing having integrally formed therein a second fluid channel (112) for the flow of the second temperature-regulating fluid. A battery module characterized by:

2. a pump (130) disposed outside the liquid-tight housing (110) and connected to the interior of the liquid-tight housing (110) via a first fluid channel (111) of the liquid-tight housing (110); Furthermore, The pump (130) is configured to generate a flow of the first temperature-conditioning fluid within the liquid-tight housing (110) by pumping the first temperature-conditioning fluid through the first fluid channel (111). The battery module according to claim 1 .

3. The fluid-tight housing (110), the pump (130), and the first fluid channel (111) form a material-closed system for the first temperature-regulating fluid. The battery module according to claim 2 .

4. The second fluid channel (112) projects into the interior of the liquid-tight housing (110). The battery module according to any one of claims 1 to 3.

5. The second fluid channel (112) has a circular cross section. The battery module according to any one of claims 1 to 4.

6. The second fluid channel (112) extends in the direction of the major axis of the battery module. The battery module according to any one of claims 1 to 5.

7. a first seal disposed circumferentially between the first end plate (114) and the profile housing (113); a second seal disposed circumferentially between the second end plate (116) and the profile housing (113); The battery module according to any one of claims 1 to 6, comprising:

8. The first seal and the second seal are flat seals. The battery module according to claim 7 .

9. Each of the first seal and the second seal is disposed in a plane perpendicular to a major axis of the battery module. The battery module according to claim 7 or 8.

10. The profile housing (113) is made of a material with a thermal conductivity of 50 W / (m·K) or more. The battery module according to any one of claims 1 to 9.

11. The profile housing (113) is made of aluminum The battery module according to any one of claims 1 to 10.

12. The first end plate (114) and / or the second end plate (116) are made of a synthetic material. The battery module according to any one of claims 1 to 11.

13. The liquid-tight housing (110) is partially filled with gas. The battery module according to any one of claims 1 to 12.

14. The volume percentage of the liquid-tight housing (110) filled with the gas is 5% or less. The battery module according to claim 13.

15. The liquid-tight housing (110) is airtight The battery module according to any one of claims 1 to 14.

16. The liquid-tight housing (110) is gas-tight up to a positive pressure of at least 1 bar The battery module according to claim 15.

17. A plurality of cell holders (140) including half-shell portions (141) configured to hold the plurality of battery cells (120), wherein the sides of the plurality of battery cells (120) are covered by the half-shell portions (141). The battery module according to any one of claims 1 to 16, further comprising:

18. Each battery cell (120) is electrically connected in parallel or series to one or more other battery cells (120) to form a battery stack. The battery module according to any one of claims 1 to 17.

19. Electrical feedthroughs (117a, 117b) connected to the battery stack The battery module of claim 18 further comprising:

20. A battery module (100) according to any one of claims 1 to 19; a secondary temperature-regulating system connected to the liquid-tight housing of the battery module and configured to establish a flow of the second temperature-regulating fluid; A battery system comprising:

21. 21. The battery system of claim 20, wherein the first temperature regulating fluid is different from the second temperature regulating fluid.

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