Energy storage unit

Abstract

The invention relates to an energy storage unit (10) comprising: a storage battery unit (12) and an insulation unit (14), wherein the storage battery unit (12) is designed to store, absorb and / or output electrical energy, wherein the energy storage unit (10) can be arranged on a boundary element (16) in order to apply a predetermined force to the storage battery unit (12), wherein the insulation unit (14) is arranged between the storage battery unit (12) and the boundary element (16), wherein the insulation unit (14) is designed to reduce a heat flow between the storage battery unit (12) and the boundary element (16).

Description

[0001] Energy storage unit

[0002] Description

[0003] State of the art

[0004] The present invention relates to an energy storage unit, a method for producing an energy storage unit and a vehicle.

[0005] There are currently a multitude of different solutions for building battery systems in the automotive sector. Due to the increasing number of battery systems resulting from the mobility transition and the increased performance requirements, the demand for innovative and robust battery systems is continuously growing.

[0006] The constant weight reduction in vehicle construction to reduce fuel consumption as well as increasing competition are creating cost pressure, so that cheaper and more efficient components for vehicles are becoming more in demand.

[0007] Disclosure of the invention

[0008] Embodiments of the invention can advantageously provide an improved energy storage unit. The invention is defined in the independent claims. Advantageous further developments of the invention emerge from the dependent claims and the following description.

[0009] An advantage of the energy storage unit with the features of claim 1 is that the thermal conductivity of the outside of the battery unit can be significantly reduced by means of the insulation unit, so that the temperature distribution within the battery unit is as uniform as possible. Preferably, a battery unit has a plurality of cells, wherein in particular the cells have an insulation unit which rests against a frame of the battery unit and / or a boundary element, so that heat flow between the battery unit with the insulation unit and the adjacent non-cell component is reduced. A further advantage can be that preferably the cells in an edge region of the battery unit have the insulation units, so that the inner cells of the battery unit can be substantially free of insulation units, which can have a beneficial effect on the manufacturing costs of the battery units.Preferably, the cell can be in a swollen state due to aging and / or charging, and the contact area between the battery unit and the frame element is reduced by the resulting bulge. Preferably, a high mechanical rigidity of the energy storage unit can be achieved because the limiting element, which can rest against a frame element, can provide the necessary rigidity, while the insulation unit can prevent heat flow. More preferably, the insulation unit can be made particularly thin, so that little additional installation space is required. A further advantage is that the insulation unit can also be used to provide electrical insulation between the battery unit and the limiting element or the like. An additional advantage is that external temperature influences on the battery unit have only a minimal effect due to the insulation unit.Furthermore, it is advantageous that heat energy from the battery unit cannot essentially be transferred to the limiting element.

[0010] This is achieved according to the invention in that the energy storage unit has a battery unit and an insulation unit, wherein the battery unit is designed to store, absorb and / or release electrical energy, wherein the energy storage unit can be arranged on a limiting element in order to apply a predetermined force to the battery unit, wherein the insulation unit is arranged between the battery unit and the limiting element, wherein the insulation unit is designed to reduce a heat flow between the battery unit and the limiting element.

[0011] In other words, both heat input and heat dissipation into the battery unit can be reduced or minimized by the insulation unit via a limiting element against which the energy storage unit rests, in order to thus make the temperature of the battery unit, in particular of the individual cells of the battery unit, as uniform as possible. The battery unit preferably comprises at least three electrochemical cells arranged essentially in parallel, with the insulation unit preferably being arranged on the first cell and the third cell. The first cell and the third cell can preferably rest against the limiting element. The limiting element is preferably part of a housing wall or module housing and / or an outer wall of a battery system. Energy storage units in vehicles are preferably mechanically braced, for example, on their side surfaces.To ensure that the temperature within the battery unit of the energy storage unit remains essentially constant, an insulation unit is preferably arranged between the battery unit and the frame element or between the battery unit and the boundary element. This allows heat flow between the battery unit and the surroundings of the battery unit to be reduced, in particular minimized. For example, heat flow between the battery unit and the boundary element can be reduced, or the thermal conductivity at the boundary element can be reduced to less than 0.1 W m. _1 K' 1 be reduced.

[0012] The subclaims show preferred developments of the invention.

[0013] Preferably, the battery unit has a separating layer, wherein a first modulus of elasticity of the separating layer is smaller than a second modulus of elasticity of the insulation unit.

[0014] An advantage of this embodiment is that the separating layer is softer in relation to the insulation unit, so that the separating layer can follow a change in volume of the battery unit and the insulation unit is stiff at the same time, so that it is very pressure-stable.

[0015] Further preferably, the battery unit has an outer side, wherein the insulation unit is arranged on the outer side of the battery unit.

[0016] An advantage of this embodiment is that the energy storage unit has increased stiffness since the outer side of the energy storage unit can provide high mechanical stiffness, such as a compression of < 10% at 1 MPa load.

[0017] Further preferably, the insulation unit is arranged on the battery unit by means of a material connection.

[0018] An advantage of this embodiment is that the insulation unit can be formed separately for connection to the battery unit. Preferably, the insulation unit can be overmolded onto the battery unit.

[0019] Preferably, the insulation unit is configured to substantially electrically insulate the battery unit from the limiting element.

[0020] One advantage is that the functional integration of the electrical insulation into the insulation unit eliminates the need for additional insulation components and improves insulation performance. Further preferably, the insulation unit forms at least one insulation structure, in particular nubs, on the battery unit.

[0021] An advantage of this embodiment is that the manufacturing costs of the energy storage unit can be further reduced, since an insulating structure such as knobs, hemispherical shapes, cylinders, truncated cones, hyperboloids or the like can be applied to the battery unit by means of a plastic injection molding process or the like.

[0022] Preferably, the insulation unit comprises a plurality of strands, wherein the plurality of strands form a lattice structure.

[0023] An advantage of this embodiment is that the lattice structure made up of a multitude of strands can be easily adapted to the individual dimensions of energy storage units, as the lattice structure can be available as a semi-finished product and only needs to be cut to size. For example, the lattice structure can be a mesh, an open woven fabric or a nonwoven fabric, a honeycomb lattice, a cross-layer lattice, or similar. For fiber-based surface materials such as woven, knitted, or nonwoven fabrics, it can be advantageous if the number of fiber layers across the thickness of the boundary element does not exceed. With a higher number of layers, increased compressibility can occur. When using materials equipped with fibers, the anisotropic properties of the fibers should be taken into account, so that the fibers always lie along the layer planes.

[0024] More preferably, the lattice density of the lattice structure is between 10% and 50%, preferably between 10% and 30%.

[0025] An advantage of this embodiment is that the predetermined force or tension forces can be absorbed by the plurality of strands, while simultaneously providing a thermally insulating effect through the lattice structure. The strands can be designed with a round and / or oval profile, limiting the contact area between the battery unit and the lattice structure to a few narrow lines, which can result in high thermal contact resistance. If the intersection points of the lattice are spatially emphasized (atomic lattice model: atoms as large spheres connected to each other by thin rods), the contact resistance between the insulation unit and the battery unit or boundary element can be further reduced.More preferably, the plurality of strands form a first layer and a second layer, wherein the insulation unit has a first carrier film, wherein the first carrier film is arranged between the first layer and the second layer.

[0026] An advantage of this design is that the carrier film can further reduce heat flow between the battery unit and the frame element or the ambient air. With round or oval strand profiles, only point-like contact can occur between the first and second layers. It would also be conceivable to create a sandwich of two insulation structures that only touch each other at a few intersection points—for example, two honeycomb layers that are not positioned congruently on top of each other.

[0027] Preferably, the insulation unit comprises a second carrier foil and a third carrier foil, wherein the second carrier foil is arranged on a first side of the plurality of strands, wherein the third carrier foil is arranged on a second side of the plurality of strands.

[0028] An advantage of this embodiment is that the manufacturing process of the insulation unit can be further simplified since a grid structure with the plurality of strands can first be formed and then a carrier film can be applied to both sides.

[0029] Further preferably, the second carrier film is designed to form a material-locking connection with the limiting element.

[0030] An advantage of this embodiment is that the second carrier film can have an adhesive layer to secure the insulation unit to the boundary element. It can be particularly advantageous that the insulation unit can be delivered to the finishing line as a complete unit, so that it can then be connected to the boundary element there.

[0031] Preferably, the insulation unit comprises at least one material selected from the group comprising at least: thermoplastics, thermosetting plastics, polyphenyl sulfide, polyimide and / or polyester.

[0032] Furthermore, the material can contain mechanically reinforcing fillers, such as glass fibers. This allows for thinner webs to be created. An advantage of this design is that, by carefully selecting the material, specific properties can be imparted to the insulation unit for a potential application scenario of the energy storage unit.

[0033] More preferably, the insulation unit comprises at least one material selected from the group comprising at least: natural building materials, wood and / or cork.

[0034] Further preferably, the insulation unit has a predetermined geometry, wherein the predetermined geometry is configured to withstand the predetermined force.

[0035] An advantage of this embodiment is that the clamping forces can be absorbed by the insulation unit or the geometry, such as a cross-section or the like, of the insulation unit can be adapted in such a way that a resistance force of the insulation unit corresponds to the predetermined force, in order to thus further reduce the required material.

[0036] It is further preferred that the insulation unit does not cover the entire surface of the battery unit and / or the boundary element. Frames are preferred here, for example, with the frame consisting of the grid structure described above. Multi-layer structures are also preferred, in which the first layer and the second layer have different surfaces. The first layer can, for example, completely cover the surface of the cell, whereas the second layer covers a partial surface of the first layer.

[0037] A further aspect of the invention relates to a battery system comprising an energy storage unit, as described above and below, wherein the battery system further comprises a frame element, wherein the frame element is configured to provide at least one limiting element, wherein an insulation unit of the energy storage unit is arranged between the limiting element and a battery unit of the energy storage unit, so that a heat flow between the battery unit and the limiting element is reduced.

[0038] Furthermore, effective thermal management can be important for battery systems or accumulator systems comprising a large number of cells. To prevent the individual cells in a battery system from aging at different rates, the temperature distribution between the individual cells can typically be below 4 Kelvin. Particularly in the case of external cells in a battery system, significantly lower temperatures can occur than in the cells within a battery system due to heat dissipation to the environment – ​​e.g., the module or battery housing. Furthermore, external cells are more susceptible to external heat sources, such as radiation from hot floors.

[0039] Further preferably, the insulation unit is arranged on the limiting element by means of a material connection.

[0040] A further aspect of the invention relates to a method for producing an energy storage unit comprising the steps:

[0041] Providing a battery unit,

[0042] - Arranging an insulation unit between the battery unit and a limiting element.

[0043] An advantage of this embodiment is that the energy storage unit can be constructed modularly, thus increasing the manufacturing costs as well as the adaptation of the energy storage unit.

[0044] More preferably, arranging the insulation unit further comprises the step:

[0045] - Forming an insulation structure on the battery unit to provide at least part of the insulation unit.

[0046] An advantage of this embodiment is that the manufacture of the energy storage unit can be further simplified since the limiting element can be formed substantially simultaneously with the insulation structure.

[0047] A further aspect of the invention relates to a vehicle having an energy storage unit as described above and below.

[0048] Furthermore, it should be noted that the term “unit” is to be understood broadly in this case and includes both a single-part design and a multi-part design of the respective units, whereby the respective unit does not have to be provided in one position in the vehicle, but can also be provided distributed within the vehicle.

[0049] All disclosures described above and below with respect to one aspect of the invention apply equally to all other aspects of the invention. Embodiments of the invention are described in detail below with reference to the accompanying drawings. In the drawing:

[0050] Figures 1 to 3f show an energy storage unit according to an embodiment,

[0051] Figures 4 and 5 show a flow chart illustrating steps of the method according to an embodiment.

[0052] Figure 6 shows a vehicle according to an embodiment.

[0053] Figure 7 shows a battery system according to an embodiment.

[0054] Embodiments of the invention:

[0055] The figures are merely schematic and not to scale. In the figures, identical, functionally identical, or similar elements may be provided with the same reference numerals.

[0056] Figure 1 shows an energy storage unit 10 according to one embodiment. The energy storage unit 10 preferably has a battery unit 12 and an insulation unit 14. The battery unit 12 is preferably configured to store, absorb, and / or release electrical energy. The energy storage unit 10 can be arranged on a limiting element 16 in order to apply a predetermined force to the battery unit 12. The insulation unit 14 is arranged between the battery unit 12 and the limiting element 16. The insulation unit 14 is configured to reduce heat flow between the battery unit 12 and the limiting element 16. As can be seen in Figure 1, the insulation unit 14 of the energy storage unit 10 preferably rests against the limiting element 16, in particular of a vehicle 200, so that a predetermined force 13 acts on the insulation unit 14 or the energy storage unit 10.An insulation unit 14 is preferably arranged between the battery unit 12 and the boundary element 16. As can be seen in Figure 1, a boundary element 16 can be formed on both sides of a battery unit 12, in particular, with an insulation unit 14 abutting each boundary element 16, the insulation units 14 abutting the battery unit 12. More preferably, the battery unit 12 comprises a separating layer 15, which can be arranged in particular between two cells of the battery unit 12. Figure 2a shows an energy storage unit 10 according to one embodiment. The energy storage unit 10 preferably has an insulation unit 14. The insulation unit 14 preferably has a plurality of strands 18 in order to be able to form a lattice structure.

[0057] Figure 2b shows an energy storage unit 10 according to one embodiment. The energy storage unit 10 preferably has an insulation unit 14 with a plurality of strands 18. As shown in Figure 2b, the insulation unit 14 preferably has a lattice structure by means of cross layers of a plurality of strands 18.

[0058] Figure 2c shows an energy storage unit 10 according to one embodiment. The energy storage unit 10 preferably comprises an insulation layer with a plurality of strands 18. The plurality of strands 18 preferably form a first layer 20 and a second layer 22, with a first carrier film 24 arranged between the first layer 20 and the second layer 22.

[0059] Figure 2d shows an energy storage unit 10 according to one embodiment. The energy storage unit 10 preferably has a boundary element 16, on which the insulation unit 14 is arranged, in particular by means of a material connection. As shown in Figure 2d, the insulation unit 14 preferably forms an insulation structure 17 on the battery unit 12, for example, by injecting nubs or the like onto the battery unit 12.

[0060] Figure 2e shows an energy storage unit 10 according to one embodiment. The energy storage unit 10 has an insulation unit 14, with an insulation structure 17 preferably formed on the battery unit 12. A first carrier film 24 can be arranged between the insulation structure 17 and the battery unit 12.

[0061] Figure 2f shows an embodiment of the energy storage unit 10. The energy storage unit 10 preferably has an insulation unit 14 with a plurality of strands 18. Preferably, a second carrier film 26 is arranged on a first side of the plurality of strands 18 and a third carrier film 28 is arranged on a second side of the plurality of strands 18. Preferably, the second carrier film 26 can form a material connection, for example an adhesive connection, with the battery unit 12.

[0062] Figure 3a shows an embodiment of the energy storage unit 10. The energy storage unit 10 preferably has an insulation unit 14, which has a plurality of strands 18 in order to be able to form, for example, a lattice structure with a honeycomb.

[0063] Figure 3b shows an energy storage unit 10 according to one embodiment. The energy storage unit 10 preferably has an insulation unit 14, which comprises a plurality of strands 18, which can form a lattice structure by means of cross-layers.

[0064] Figure 3c shows an energy storage unit 10 according to one embodiment. The energy storage unit 10 preferably has an insulation unit 14 with a plurality of strands 18. As can be seen in Figure 3c, the plurality of strands 18 preferably form a first layer 20 and a second layer 22. Further preferably, a first carrier film 24 is arranged between the first layer 20 and the second layer 22.

[0065] Figure 3d shows an energy storage unit 10 according to one embodiment. The energy storage unit 10 preferably has an insulation unit 14, which can preferably be arranged on the battery unit 12. The insulation unit 14 can form an insulation structure 17, which can be, for example, studs or the like.

[0066] Figure 3e shows an energy storage unit 10 according to one embodiment. The energy storage unit 10 preferably comprises an insulation unit 14, which is arranged on a first carrier film 24 applied to the battery unit 12.

[0067] Figure 3f shows an embodiment of the energy storage unit 10. The energy storage unit 10 preferably has an insulation unit 14, which comprises a plurality of strands 18. Preferably, a second carrier film 26 is arranged on a first side of the plurality of strands 18, and a third carrier film 28 is arranged on a second side of the plurality of strands 18.

[0068] Figure 4 shows a flowchart illustrating steps of the method 100 for producing an energy storage unit 10. The method 100 preferably comprises the steps:

[0069] Providing S1 a battery unit 12,

[0070] - Arranging S2 an insulation unit 14 between the battery unit 12 and a limiting element 16.

[0071] Figure 5 shows a flowchart illustrating steps of method 100 according to one embodiment. Method 100 preferably comprises the same steps S1 and S2 as already explained with reference to Figure 4. More preferably, method 100 further comprises the following step:

[0072] - Forming S3 an insulation structure 17 on the battery unit 12 for providing at least a part of the insulation unit 14.

[0073] Figure 6 shows a vehicle 300 according to one embodiment. The vehicle 300 preferably has an energy storage unit 10, as described above and below.

[0074] Figure 7 shows a battery system 200 according to one embodiment. The battery system 200 preferably has an energy storage unit 10, as described above and below.

Claims

Claims 1. Energy storage unit (10) comprising: a battery unit (12), an insulation unit (14), wherein the battery unit (12) is configured to store, absorb and / or release electrical energy, wherein the energy storage unit (10) can be arranged on a limiting element (16) in order to apply a predetermined force to the battery unit (12), wherein the insulation unit (14) is arranged between the battery unit (12) and the limiting element (16), wherein the insulation unit (14) is configured to reduce a heat flow between the battery unit (12) and the limiting element (16).

2. Energy storage unit (10) according to claim 1, wherein the battery unit (12) has a separating layer (15), wherein a first modulus of elasticity of the separating layer (15) is smaller than a second modulus of elasticity of the insulation unit (14).

3. Energy storage unit (10) according to one of the preceding claims, wherein the insulation unit (14) is arranged on the battery unit (12) by means of a material connection.

4. Energy storage unit (10) according to one of the preceding claims, wherein the insulation unit (14) is configured to substantially electrically insulate the battery unit (12) from the limiting element (16).

5. Energy storage unit (10) according to one of the preceding claims, wherein the insulation unit (14) forms at least one insulation structure (17), in particular knobs, on the battery unit (12).

6. Energy storage unit (10) according to one of the preceding claims, wherein the insulation unit (14) has a plurality of strands (18), wherein the plurality of strands (18) form a lattice structure.

7. Energy storage unit (10) according to claim 6, wherein the lattice density of the lattice structure is between 10% and 50%, preferably between 10% and 30%.

8. Energy storage unit (10) according to one of claims 6 to 7, wherein the plurality of strands (18) form a first layer (20) and a second layer (22), wherein the insulation unit (14) has a first carrier film (24), wherein the first carrier film (24) is arranged between the first layer (20) and the second layer (22).

9. Energy storage unit (10) according to one of claims 6 to 7, wherein the insulation unit (14) comprises a second carrier foil (26) and a third carrier foil (28), wherein the second carrier foil (26) is arranged on a first side of the plurality of strands (18), wherein the third carrier foil (28) is arranged on a second side of the plurality of strands (18).

10. Energy storage unit (10) according to one of the preceding claims, wherein the insulation unit (14) comprises at least one material selected from the group at least comprising: thermoplastics, thermosetting plastics, polyphenyl sulfide, polyimide and / or polyester.

11. Energy storage unit (10) according to one of claims 1 to 9, wherein the insulation unit (14) comprises at least one material selected from the group at least comprising: natural building materials, wood and / or cork.

12. Battery system (200) comprising an energy storage unit (10) according to one of the preceding claims, wherein the battery system (200) further comprises a frame element (202), wherein the frame element (202) is configured to provide at least one limiting element (16), wherein an insulation unit (16) of the energy storage unit (10) is arranged between the limiting element (16) and a battery unit (12) of the energy storage unit (10), such that a heat flow between the battery unit (12) and the limiting element (16) is reduced.

13. A method (100) for producing an energy storage unit (10) comprising the steps: Providing (S1) a battery unit (12), - Arranging (S2) an insulation unit (14) between the battery unit (12) and a limiting element (16).

14. The method (100) according to claim 13, wherein the arranging (S2) of the insulation unit (14) further comprises the step: Forming (S3) an insulation structure (17) on the battery unit (12) for providing at least part of the insulation unit (14).

15. Vehicle (300) comprising an energy storage unit (10) according to one of claims 1 to 11 and / or a battery system (200) according to claim 12.

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