WO2024022999A1

WO2024022999A1 - Electric energy storage device with a degassing line

Info

Publication number: WO2024022999A1
Application number: PCT/EP2023/070406
Authority: WO
Inventors: Martin Wichtrei; Markus Lampalzer; Sebastian Kratzer; Michael Klauke; Mathias Wacker; Franco Zemczak
Original assignee: Man Truck & Bus Se
Priority date: 2022-07-28
Filing date: 2023-07-24
Publication date: 2024-02-01
Also published as: DE102022118992A1

Abstract

The invention relates to an electric energy storage device (10) for a motor vehicle. The electric energy storage device (10) has a plurality of battery cells (12), each of which has a degassing element (12a) for degassing the cell. The electric energy storage device (10) additionally has a degassing line (14) which fluidically connects the degassing elements (12a) of the plurality of battery cells (12) together. The degassing line (14) has a heat-resistant material (16), namely a silicate and/or a high-temperature plastic.

Description

Electrical energy storage with a degassing line

Description

The invention relates to an electrical energy storage device and a motor vehicle with such an energy storage device.

Electrical energy storage devices (e.g. high-voltage batteries) for motor vehicles usually consist of a large number of battery cells that are electrically interconnected or can be interconnected. Especially when using lithium-ion battery cells, external influences or a fault in one of the battery cells (e.g. an internal short circuit) can lead to thermal runaway. Large amounts of energy are released through internal exothermic reactions, with at least part of the cell's electrolyte changing into a gaseous state. The temperature of the gas can reach peak values of several hundred °C and even over 1000 °C. Furthermore, the gas stream can also contain conductive particles, which under certain circumstances can lead to a short circuit on live components. In the energy storage, this can lead to chain reactions (thermal propagation), which can ultimately destroy the entire energy storage.

In order to divert the gas flow from battery cells in the most controlled manner possible in the event of a fault, it is known in the prior art to provide appropriate pressure or safety valves, so-called “safety vents”, on the battery cells. As an example, reference is made to US 2006/0292437A1. To avoid damage to other battery components, the corresponding gas stream should be carried out of the electrical energy storage device as separated as possible from the remaining battery components, which can be achieved, for example. B. can be done via appropriate channel systems.

A disadvantage of the known solutions for gas removal is often their high weight, e.g. B. due to correspondingly thick walls to ensure sufficient temperature resistance in the event of a fault.

The invention is therefore based on the object of providing an improved device for energy storage for a motor vehicle. It is preferably an object of the invention to provide a solution that is as simple and light as possible, by means of which the highest possible protection against thermal propagation can be achieved. These tasks can be solved with the features of the independent claims. Advantageous embodiments and applications of the invention are the subject of the dependent claims and are explained in more detail in the following description with partial reference to the figures.

A first independent aspect of the present disclosure relates to an electrical energy storage device for a motor vehicle. The electrical energy storage is preferably an electrical energy storage for a commercial vehicle, e.g. B. for a truck and/or a bus.

The electrical energy storage has several battery cells (e.g. lithium-ion battery cells), each of which preferably has a degassing element for cell degassing (e.g. a pressure relief valve). The plurality of battery cells are preferably arranged next to one another and/or all oriented in the same way. For example, the multiple battery cells can each be arranged with their degassing element oriented upwards.

The electrical energy storage further has a degassing line, which fluidly connects the degassing elements of the plurality of battery cells to one another. For example, the degassing line can be designed as a pipeline. The corresponding degassing line preferably serves to collect or absorb substances (e.g. gases and/or particles) emerging from the respective degassing elements during cell degassing and/or to discharge (e.g. control) these substances from the electrical energy storage device.

The electrical energy storage is characterized in that the degassing line has a heat-resistant material, namely a preferably mineral silicate (e.g. mica) and/or a high-temperature plastic (e.g. a polyimide). By way of example only, a part of the degassing line, onto which the (hot) substances of the battery cells can impinge immediately after their release from the respective degassing elements, can be made of mica, while other areas of the degassing line that are less exposed to temperature can be made of the high-temperature plastic. In an advantageous manner, a temperature-resistant and, in particular in comparison to otherwise usual steel components, a gas outlet that is as weight-saving as possible can be provided, by means of which gases and/or particles released during cell degassing can be collected or removed as separated as possible from the other components of the energy storage device. According to one aspect, the heat-resistant material may have a melting temperature of at least 150 °C, preferably at least 250 °C, particularly preferably at least 400 °C. For example, the heat-resistant material can thus melt from a temperature of 150 ° C, preferably 250 ° C, particularly preferably 400 ° C, that is, change from the solid to the liquid aggregate state.

In another aspect, the silicate may include mica (e.g., muscovite or phlogopite). For example, the silicate or the heat-resistant material can be natural mica plates and / or artificial mica, such as. B. micanite. Artificial mica, which can also be referred to as pressed mica, preferably has (e.g. natural) mica fragments (e.g. mica waste) which are pressed with a, preferably heat-resistant, binder (e.g. with a silicone resin). The proportion of binder is preferably <15%, particularly preferably <10%. Due to the high temperature resistance of mica (melting point > 1200 °C) as well as its low density and therefore its low weight, safe and easy heat protection of the degassing line can be achieved in an advantageous manner.

Additionally or alternatively, the high-temperature plastic can comprise a, preferably aromatic, polyimide (e.g. Vespel). The polyimide preferably has an imide group in its molecular structure, consisting of two acyl groups bonded to nitrogen. Like mica, polyimide also has good temperature resistance and low weight, so that a light and safer degassing line can also be advantageously created with this material. In particular, the high-temperature plastic can be used in areas of the degassing line that are less exposed to high temperatures.

According to a further aspect, the degassing line can be designed to collect substances (e.g. gases and/or particles) emerging from the plurality of battery cells via the degassing elements and preferably to direct them out of the electrical energy storage device. The degassing line can z. B. be tubular and / or channel-shaped. The degassing line can be in fluid communication with the respective degassing elements of the plurality of battery cells, for example via corresponding openings in the degassing line and/or supply lines.

Additionally or alternatively, the degassing line can be designed to at least partially limit a receiving space for substances emerging from the respective degassing elements. The receiving space is preferably separated (fluidically). of live components of the battery cells (e.g. their contacts) or the electrical energy storage (e.g. HV rails). In an advantageous manner, thermal and/or electrical damage to the battery cells can be avoided as far as possible.

According to a further aspect, the degassing line can (e.g. at least in sections) have a hollow profile section. By way of example only, the hollow profile section can have a rectangular, square or other (circumferentially) closed cross-section, which preferably delimits the receiving space on the circumferential side. In one embodiment, the hollow profile section has a plurality of through openings (e.g. holes and/or recesses), which are preferably arranged in alignment with the respective degassing elements. For example, one of the multiple through openings can be arranged above one of the multiple degassing elements. The plurality of through openings can also each be designed to enable a (free or unhindered) passage of the substances emerging from the respective degassing elements during cell degassing into the degassing line or the receiving space. In an advantageous manner, a gas discharge that is as closed or sealed as possible can be provided.

Additionally or alternatively, the degassing line can (e.g. at least in sections) have an open profile section (e.g. a U-, C- and/or hat-profile section). As is usual in connection with profiles, the term “open” profile should preferably refer to a cross section of the profile (profile cross section). In general, a distinction can be made between closed hollow profiles (e.g. pipes), which have no opening, and open profiles (such as U-profiles, C-profiles and/or hat profiles), which have an opening. The open profile section preferably has a cross section that is open towards the respective degassing elements. For example, the open profile section can be arranged such that an opening of the open profile section faces the degassing elements. The open profile section is preferably connected at least in sections to the plurality of battery cells (possibly via a seal) or delimits the receiving space together with them. In an advantageous manner, a gas discharge that is as easy to install as possible can be provided.

According to a further aspect, the degassing line can have a base body (e.g. made of plastic) to which the heat-resistant material (e.g. artificial mica) is applied as a coating. The base body can thus be coated with the heat-resistant material. For example, the coating can have a thickness of less than 2 mm, preferably less than 1 mm. As will be explained below, this can advantageously achieve an application of the heat-resistant material that is as needs-based as possible.

According to a further aspect, the coating may have a first region with a first thickness of the coating and a second region with a second thickness of the coating that is different from the first thickness. For example, the thickness in the second area can be specifically increased or reinforced, e.g. B. in order to increase the temperature resistance of the degassing line in this area. For example, the second area can be a particularly temperature-exposed area, e.g. B. act in an area arranged opposite the degassing elements, the degassing line.

Additionally or alternatively, the coating can be arranged, preferably exclusively, on a surface of the base body facing the respective degassing elements. For example, the coating can be arranged (e.g. only) on an inside (e.g. delimiting the receiving space) of the hollow profile section and/or the open profile section. In an advantageous manner, a resistant impact surface can be provided as required as possible for the (hot) substances emerging from the respective degassing elements during cell degassing.

According to a further aspect, the heat-resistant material can be formed as a (e.g. pressed and/or cast) molded part (e.g. as a tube). For example, the entire degassing line (e.g. continuously) can be made of the heat-resistant material. In one embodiment, for example, mica fragments can be pressed into a predetermined shape using a synthetic resin (e.g. epoxy or a silicone resin) as a binder and then baked under pressure and temperature.

Additionally or alternatively, the degassing line can essentially (e.g. continuously) consist of the heat-resistant material. In contrast to the coating of a base body, according to this variant, the degassing line can, for example, be formed essentially exclusively from the heat-resistant material. Overall, the highest possible temperature resistance of the degassing line can be achieved in an advantageous manner. According to a further aspect, the electrical energy storage can have a cover plate. This cover plate can be arranged between the degassing line and the multiple battery cells and cover the multiple battery cells. The cover plate preferably serves to protect the plurality of battery cells from substances escaping from the respective degassing elements, e.g. B. conductive particles. Additionally or alternatively, the cover plate can also serve as protection against contact and, for example. B. Cover the contacts of the several battery cells. The safety of the electrical energy storage can thereby be further increased in an advantageous manner.

According to a further aspect, the cover plate can have a plurality of passages (e.g. holes), wherein the several passages can each be arranged correspondingly (e.g. aligned) to the respective degassing elements. For example, one of the multiple passages can be arranged above one of the multiple degassing elements. The multiple passages can each be designed to allow (free or unhindered) passage of the substances emerging from the respective degassing elements during cell degassing (through the cover plate) into the degassing line or the receiving space. In order to enable the most reliable protection of the battery cells in this context and to influence the cell degassing as little as possible, a contour of the respective passages can be designed to correspond in shape to a respective outer contour of the associated degassing elements.

Additionally or alternatively, the cover plate may cover a side surface of each of the plurality of battery cells. The cover plate can therefore extend at least in sections over all of the several battery cells. However, this should preferably not exclude the possibility that, under certain circumstances, additional components (e.g. contacting elements) can also be arranged in sections between the cover plate and the plurality of battery cells. In one embodiment, the cover plate can cover a top surface of each of the several battery cells. The cover plate can therefore z. B. be arranged above the several battery cells.

Additionally or alternatively, the cover plate, together with the degassing line, can limit a receiving space for substances emerging from the respective degassing elements. For example, in one embodiment, the cover plate can limit the receiving space together with the open profile section (e.g. designed as a U-profile section). Here, the cover plate can cover the receiving space, for example. B. downwards and the degassing line limits the receiving space upwards.

According to a further aspect, the electrical energy storage can have at least one outlet valve (e.g. a pressure relief valve). The at least one outlet valve can be arranged on a housing of the electrical energy storage device. For example, the housing can have a passage in which the at least one outlet valve is arranged. The at least one outlet valve preferably serves to remove the substances emerging from the respective degassing elements from the housing. A connection to the environment or to the outside of the electrical energy storage can thus be enabled via the at least one outlet valve. Here, the at least one outlet valve can be fluidly connected to the degassing line. For example, the degassing line can open into the at least one outlet valve. In an advantageous manner, the substances released during cell degassing can be removed from the electrical energy storage device.

According to a further aspect, the plurality of battery cells can be arranged in the form of at least two battery cell stacks. The at least two battery cell stacks preferably each have the same stacking direction. For example, the at least two battery cell stacks can be arranged next to each other, offset in parallel.

Additionally or alternatively, the degassing line can have at least two straight main line sections. For example, these can each be assigned to one of the at least two battery cell stacks. The at least two straight main line sections can, for example, each extend along the respective battery cell stack. One of the at least two straight main line sections can be arranged above one of the at least two battery cell stacks.

Furthermore, the degassing line can have at least one connecting line section that connects the two straight main line sections to one another. The at least one connecting line section preferably runs perpendicular to the at least two straight main line sections. The at least one connecting line section can be designed as a separate component, which can be attached (e.g. glued) to the two straight main line sections. Alternatively, the at least one connecting line section can be used together with the two straight ones Main line sections can be designed as a one-piece component, in which the aforementioned components z. B. are integrally connected to one another.

According to a further aspect, the at least one connecting line section can extend at least in sections above the two straight main line sections. The two straight main line sections can thus be arranged below the at least one connecting line section with respect to a vertical axis of the electrical energy storage. For example, the at least one connecting line section can connect the two straight main line sections to one another in an arc.

Alternatively, the at least one connecting line section can extend at least in sections below the two straight main line sections. The two straight main line sections can thus be arranged above the at least one connecting line section with respect to a vertical axis of the electrical energy storage. For example, the at least one connecting line section can run or be arranged laterally next to the plurality of battery cells (e.g. at one or more stack ends).

According to a further aspect, the electrical energy storage can have at least one sealing element. The at least one sealing element can be arranged between the degassing line and the plurality of battery cells. The at least one sealing element can z. B. be designed in the form of a sealing ring or in the form of an elastomer mat. The at least one sealing element can be made of an elastic material. The at least one sealing element preferably serves to seal a gap located between the degassing line and the plurality of battery cells. This can advantageously ensure that the gases and/or particles released during cell degassing reach the degassing line or the receiving space as completely as possible.

Furthermore, the disclosure relates to a motor vehicle (e.g. a truck or a bus), the motor vehicle having an electrical energy storage device as disclosed in this document. The motor vehicle is preferably a commercial vehicle, ie a motor vehicle which, due to its design and equipment, is specifically designed to transport goods and/or to tow one or more (e.g. agricultural) trailer vehicles. For example, the commercial vehicle can be a truck, a semi-trailer, a construction site vehicle and/or an agricultural machine (e.g. a tractor).

The previously described aspects and features of the present disclosure can be combined with one another in any way. Further details and advantages are described below with reference to the accompanying drawings. Show it:

Figure 1A shows a schematic representation of an electrical energy storage device according to an embodiment;

Figure 1B shows a schematic representation of an electrical energy storage device with a degassing line according to an embodiment;

Figures 2A-2C various views of a degassing line according to an embodiment;

Figures 3A-3C show schematic representations of degassing lines according to various further embodiments;

4A shows a schematic representation of an electrical energy storage device with a degassing line according to a further embodiment; and

Figures 4B-5B various views of a degassing line according to another

Embodiment.

The embodiments shown in the figures are at least partially identical, so that similar or identical parts are provided with the same reference numbers and for their explanation reference is also made to the description of the other embodiments or figures in order to avoid repetition. Furthermore, for reasons of clarity, components that occur multiple times were not referenced separately.

Figures 1A, 1B and 4A show (partially) embodiments of an electrical energy storage device 10 for a motor vehicle (not shown). The electrical energy storage 10 can provide electrical energy for at least one electrical drive unit for driving the motor vehicle. For example, the motor vehicle can be driven by a central electric drive, by several electric wheel hub drives or by several electric drives close to the wheel. The electrical energy storage 10 can be designed as a high-voltage energy storage device. The high-voltage energy storage can z. B. with one DC voltage between 60 V and 1.5 kV, particularly preferably between 400 V and 850 V, can be operated or operated. The electrical energy storage 10 can be charged externally via an electrical charging cable connected to a charging socket of the motor vehicle.

The electrical energy storage 10 has several (e.g. forty-eight) battery cells 12. The multiple battery cells 12 can, for. B. lithium-ion battery cells. The multiple battery cells 12 can each be designed the same. The multiple battery cells 12 can each have an electrolyte and an electrode stack and/or electrode coil. The multiple battery cells 12 can each have a cell housing. An electrolyte and an electrode stack or electrode coil can be accommodated in the respective cell housings. The cell housing can have a top surface, a bottom surface and a lateral surface connecting the top and bottom surfaces. In a preferred embodiment, the plurality of battery cells 12 may each be prismatic battery cells. However, the multiple battery cells 12 can also be designed as bag cells or as round cells.

The multiple battery cells 12 can be arranged in one layer. The plurality of battery cells 12 are preferably all oriented in the same way (cf. FIG. 1 A). For example, the top surfaces of the plurality of battery cells 12 can each be oriented upwards. Within the layer, the multiple battery cells 12 can be arranged in the form of a battery cell stack or multiple battery cell stacks. For example, the plurality of battery cells 12 can be arranged in the form of at least two (e.g. three), preferably parallel, battery cell stacks. The battery cell stacks can each have the same design or each have the same number of battery cells 12 (e.g. sixteen battery cells 12). Within a battery cell stack, the battery cells 12 can be arranged next to one another or stacked one behind the other along a stacking direction. The stacking direction can be oriented horizontally, for example. The at least two battery cell stacks preferably each have the same stacking direction. Furthermore, it is possible for a gap filler (e.g. a gap pad) to be arranged between two of the battery cells 12 of a battery cell stack in order to bridge a gap between the battery cells 12 of a battery cell stack.

The plurality of battery cells 12 may each have contact poles 12b (e.g. a positive pole and a negative pole). The respective contact poles 12b can z. B. be arranged on the respective top surfaces of the battery cells 12. The contact poles 12b of the several Battery cells 12 can be connected to one another (e.g. in series). For this purpose, the electrical energy storage 10 can have a cell contacting system (not shown).

The plurality of battery cells 12 preferably also each have a degassing element 12a for cell degassing. For example, the respective degassing elements 12a can each be designed in the form of a pressure relief valve and/or in the form of a material weakening or predetermined breaking point (e.g. in the form of a rupture disk). The respective degassing elements 12a can open automatically when a pressure threshold value is exceeded inside the respective battery cells 12 or within the cell housing. The respective degassing elements 12a can thus serve to protect the respective battery cells 12 from damaging excess pressure. Accordingly, the respective degassing elements 12a can be designed to produce a gas stream from a respective interior of the cell housing, e.g. B. along a predetermined degassing path into an environment of the respective battery cell 12. The respective degassing elements 12a can each be arranged on the same side surface of the respective battery cells 12 as the contact poles 12b. For example, the respective degassing elements 12a can be arranged on the respective cover surfaces of the battery cells 12 (e.g. between the contact poles). Accordingly, the degassing elements 12a of the plurality of battery cells 12 of the electrical energy storage device 10 can all be oriented upwards.

The electrical energy storage 10 can also have a housing 11. The housing 11 can z. B. made of a metal alloy or plastic. The multiple battery cells 12 can be accommodated in the housing 11. The housing 11 can serve to protect the multiple battery cells 12 against external influences, in particular dirt and/or moisture. The housing 11 can be frame-shaped, preferably polygonal-frame-shaped (e.g. rectangular-frame-shaped). The housing 11 is preferably completely circumferential or forms a closed, multi-sided (e.g. four-sided) frame (see, for example, Figure 1 A).

The housing 11 can have a length. This can, for example, denote a spatial extent along a longitudinal axis L of the housing 11 or the energy storage device 10. The longitudinal axis L can, for example, run in the direction of the longest extension of the housing 11 or the energy storage device 10. The housing 11 can also have a width. This can, for example, denote a spatial extent along a transverse axis Q of the housing 11 or the energy storage device 10. The transverse axis Q can, for example, be oriented in a further direction perpendicular to the longitudinal axis L. For example, the longitudinal axis L and transverse axis Q can each be oriented horizontally. Furthermore, the housing 11 or the energy storage 10 can have a vertical axis H. This can preferably be perpendicular to the longitudinal axis L and transverse axis Q. For example, the vertical axis H can be oriented vertically or parallel to the direction of gravity.

The energy storage 10 can also have a, preferably plate-shaped, base (not shown). The floor can cover the housing 11 from below.

The energy storage 10 can also have a, preferably plate-shaped, cover (not shown). The lid can cover the housing 11 from above.

The electrical energy storage 10 also has a degassing line 14 (e.g. in the form of a pipeline) (see, for example, Figures 1 B and 4A). The degassing line 14 can be arranged in the housing 11 or accommodated in the housing 11. The degassing line 14 preferably serves to collect the substances (e.g. gases and/or particles) emerging from the respective degassing elements during cell degassing as separated as possible from the other components of the electrical energy storage 10 or to collect the substances from the electrical energy storage in as controlled a way as possible 10 to be discharged.

For this purpose, a receiving space 20 can be formed in the degassing line 14 for the substances emerging from the respective degassing elements 12a. For example, the receiving space 20 can be designed as a free cavity delimited by the degassing line 14 (e.g. inside the degassing line 14). Accordingly, the degassing line 14 or the energy storage 10 can have the receiving space 20. The receiving space 20 can be fluidically separated from other components of the electrical energy storage 10 (e.g. the contact poles 12b of the plurality of battery cells) by the degassing line 14.

Furthermore, the respective degassing elements 12a of the plurality of battery cells 12 can be fluidly connected to one another via the degassing line 14. The degassing line 14 or the receiving space 20 can z. B. be arranged above the several battery cells 12 or above the respective degassing elements 12a. The degassing line 14 or the receiving space 20 can thus be aligned essentially in a horizontal plane. Furthermore, the degassing line 14 can at least partially be connected directly to the several battery cells 12 rest or be connected to the several battery cells 12 via a seal (not shown).

The degassing line 14 can be tubular and/or tubular. For example, the degassing line 14 can (e.g. at least in sections) have a hollow profile section 14a (cf. e.g. Figure 3A). This can e.g. B. have a rectangular, square or other (circumferentially) closed cross section. Preferably, the hollow profile section 14a therefore has, at least in sections, a completely circumferential wall (on the circumferential side). The hollow profile section 14a can, for example, have a width of 50-80 mm and/or a height of up to 20 mm. The hollow profile section 14a can limit the receiving space 20 for the substances emerging from the respective degassing elements 12a. For example, the receiving space 20 can be designed as a free cavity delimited by the hollow profile section 14a. The hollow profile section 14a can be oriented essentially along the transverse axis Q of the housing 11 or the energy storage 10 or have its longest extension along the transverse axis Q.

In order to enable the substances released during cell degassing to flow into the degassing line 14 or the hollow profile section 14a, the hollow profile section 14a or the degassing line 14 can have a plurality of through openings 15 (e.g. holes and/or recesses). The receiving space 20 can be connected (fluidically) to the degassing elements 12a via the multiple through openings 15. The plurality of through openings 15 should preferably be arranged on a lateral surface of the hollow profile section 14a. For example, the plurality of through openings 15 can be arranged on an underside of the hollow profile section 14a, preferably facing the plurality of battery cells 12 (cf. Figures 2C and 5A). In addition, the hollow profile section 14a can have one or two front openings. The multiple through openings 15 can each be arranged aligned or aligned with the respective degassing elements 12a. For example, one of the multiple through openings 15 can be arranged above one of the multiple degassing elements 12a. Accordingly, one of the several through openings 15 can be assigned to one of the degassing elements 12a. The multiple through openings 15 can also be arranged in a grid and/or a pattern. For example, the plurality of through openings 15 can be arranged in one row or in several rows (e.g. three), preferably arranged parallel next to one another. Preferred the grid and/or the pattern of the plurality of through openings 15 corresponds to a grid and/or pattern in which the plurality of battery cells 12 or their degassing elements 12a are arranged.

The degassing line 14 can also be trough-shaped and/or channel-shaped. For example, the degassing line 14 can have (e.g. at least in sections) an open profile section 14b (cf. Figures 3B and 3C). For example, the degassing line 14 (e.g. at least in sections) can have a II, C and/or hat profile section. The open profile section 14b should preferably have an open (e.g. open on one side) cross section or a cross section with an opening. Preferably, the opening of the cross section faces the degassing elements 12a or is oriented in the direction of the degassing elements 12a. For example, it can be a II, C and/or hat profile section that is open at the bottom. The open profile section 14b can limit the receiving space 20 for the substances emerging from the respective degassing elements 12a. The receiving space 20 can, for example, be designed as a free cavity delimited by the open profile section 14b. In one embodiment, the open profile section 14b can limit the receiving space 20 laterally and upwards.

Furthermore, the receiving space 20 can also be limited by the several battery cells 12. For example, the receiving space 20 can be delimited at the bottom by the several battery cells 12. For this purpose, the open profile section 14b can be connected to the several battery cells 12 (e.g. their top surfaces). The open profile section 14b, preferably open in the direction of the plurality of battery cells 12, can be z. B. at least in sections rest directly on the several battery cells 12 or be connected to the several battery cells 12 via a seal (not shown).

Furthermore, the electrical energy storage 10 can have at least one cover plate 18 (see FIG. 3C). This can be arranged between the degassing line 14 (e.g. the open profile section 14b) and the several battery cells 12. Accordingly, the degassing line 14 can be connected to the plurality of battery cells 12 via the cover plate 18. Here too, a seal (not shown) can be arranged between the cover plate 18 and the several battery cells 12 or between the cover plate 18 and the degassing line 14. The at least one cover plate 18 can cover the plurality of battery cells 12 (e.g. their cover surfaces and/or their contact poles 12b). For example, the cover plate 18 can span the plurality of battery cells 12 (e.g. their top surfaces). The at least one cover plate 18 is preferably used Protection of the several battery cells 12 or their contact poles 12b from substances emerging from the respective degassing elements 12a, such as. B. conductive particles. Furthermore, the at least one cover plate 18 can also serve as protection against contact.

The at least one cover plate 18 can have a flat and/or flat shape. For example, the cover plate 18 can be essentially cuboid-shaped. The at least one cover plate 18 can be aligned essentially horizontally. The at least one cover plate 18 can include a (e.g. lower) side surface facing the plurality of battery cells 12, which can also be referred to as the first side surface. The at least one cover plate 18 may further comprise a second side surface that is opposite (e.g. upper) to the first side surface. The second side surface can be coated with a heat-resistant material. The second side surface can limit the receiving space 20 (e.g. downwards).

The at least one cover plate 18 can have several passages 18a (e.g. holes). The multiple passages 18a can each be arranged aligned or aligned with the respective degassing elements 12a. For example, one of the multiple passages 18a can be arranged above one of the multiple degassing elements 12a. Accordingly, one of the several passages 18a of the at least one cover plate 18 can be assigned to one of the degassing elements 12a. The multiple passages 18a may further be arranged in a grid and/or a pattern. For example, the plurality of passages 18a can be arranged in one row or in several rows (e.g. three), preferably arranged in parallel next to one another. The grid and/or the pattern of the plurality of passages 18a preferably corresponds to a grid and/or pattern in which the plurality of battery cells 12 or their degassing elements 12a are arranged. The at least one cover plate 18 can also include several cover plates 18, preferably of the same design. The at least one cover plate 18 can therefore also be designed in several parts. For example, the plurality of cover plates 18 can each be assigned to one of the battery cell stacks and/or joined together.

Furthermore, the electrical energy storage 10 can have at least one outlet valve (not shown) which is arranged on the housing 11. The at least one outlet valve can z. B. be arranged on a side surface of the housing 11. For example, the at least one outlet valve can be arranged on the housing 11 at the level of the battery cells 12. The at least one outlet valve can be in the form of a pressure relief valve and/or a in the form of a material weakening or predetermined breaking point (e.g. in the form of a rupture disk) in the housing 11. The at least one outlet valve can be connected (fluidically) to the degassing line 14 or the receiving space 20. For example, the degassing line 14 or the receiving space 20 can open into the at least one outlet valve or into an outlet line connected to the at least one outlet valve. The at least one outlet valve can open automatically when a pressure threshold value in the degassing line 14 or in the receiving space 20 is exceeded. The at least one outlet valve can be designed to allow a gas flow to escape from the degassing line 14 or from the receiving space 20 into an environment of the housing 11. In the case of cell degassing, the substances emerging from one of the degassing elements 12a can, for example, first flow into the degassing line 14 or the receiving space 20 and from there reach at least one outlet valve 13, where they can ultimately be discharged into the outside space. It is also possible for the at least one outlet valve to comprise a plurality of outlet valves or for the electrical energy storage device 10 to have a plurality of such outlet valves.

In order to collect the substances released during cell degassing or to direct them to the outlet valve, different configurations of the degassing line 14 are possible (cf. Figures 1 B and 4A). For example, the degassing line 14 can have at least two (e.g. three) straight main line sections 14.1. The at least two straight main line sections 14.1 can each be assigned to one of the at least two battery cell stacks. Thus, one of the at least two straight main line sections 14.1 can extend continuously along one of the at least two battery cell stacks. For example, a first straight main line section of the at least two straight main line sections 14.1 can cover or span all battery cells 12 of a first of the at least two battery cell stacks and a second straight main line section of the at least two straight main line sections 14.1 can cover or span all battery cells 12 of a second of the at least two battery cell stacks. The at least two straight main line sections 14.1 can be arranged parallel to one another and/or at the same height. The at least two straight main line sections 14.1 can each be oriented along the transverse axis Q of the energy storage 10 or the housing 11 or have their longest extension along the transverse axis Q. The at least two straight main line sections 14.1 can each be closed on one of their end faces. The at least two straight main line sections 14.1 can each be designed in the form of the aforementioned hollow profile section 14a or the open profile section 14b or each have the aforementioned hollow profile section 14a or open profile section 14b.

Furthermore, the degassing line 14 can have at least one connecting line section 14.2, which connects the two straight main line sections 14.1 to one another. The at least one connecting line section 14.2 preferably runs perpendicular to the at least two straight main line sections 14.1. The at least one connecting line section 14.2 can thus be oriented along the longitudinal axis L of the energy storage 10 or the housing 11. The at least one connecting line section 14.2 can extend at least in sections above or below the two straight main line sections. For example, the at least one connecting line section 14.2 can contain the two straight main line sections

14.1 connect in the form of an arch that is open at the bottom or top (see Figure 2B or 5B). In one embodiment, the at least one connecting line section 14.2 can be arranged at least in sections at the level of the plurality of battery cells 12. For example, the at least one connecting line section 14.2 can be arranged adjacent or adjacent to respective end faces of the at least two battery cell stacks.

Furthermore, the at least one connecting line section 14.2 can each be arranged at an end region of the two straight main line sections 14.1. In the case of three parallel main line sections 14.1, which are connected in pairs via a connecting line section 14.2, the degassing line 14 can thus be designed in the form of the letter “E”. However, the at least one connecting line section 14.2 can be arranged in a central area of the two straight main line sections 14.1 or in an area between the end area and the middle area (see Figures 4B and 5A). Furthermore, the at least one connecting line section 14.2 can have several (e.g. two) connecting line sections

14.2 include. These can e.g. B. can be arranged spaced apart from one another along the transverse axis Q. In the case of three parallel main line sections 14.1, e.g. B. two of the main line sections 14.1 can be connected in a central area via a connecting line section 14.2 in the form of the letter “H”, while two of the main line sections 14.1 can be connected to one another via two spaced-apart connecting line sections 14.2. The present degassing line 14 is further characterized in that it has a heat-resistant material 16, namely a silicate and/or a high-temperature plastic (see Figures 3A-3C). A heat-resistant material 16 can be understood as a material that withstands high temperatures (e.g. temperatures > 100 ° C) or retains its characteristic properties even at high temperatures. For example, the heat-resistant material 16 can have a melting temperature of at least 150 ° C, preferably at least 250 ° C, particularly preferably at least 400 ° C.

Salts and esters of ortho-silicic acid and their condensates can be understood as silicate. The silicate can be, for example, a mineral silicate, such as. B. mica. By way of example only, the degassing line 14 or the heat-resistant material 16 can be natural mica plates and/or natural mica fragments, e.g. B. made of muscovite or phlogopite. The mica fragments can be bonded with a, preferably heat-resistant, binder (e.g. with a silicone resin) to form so-called artificial mica or pressed mica. The degassing line 14 or the heat-resistant material 16 can, for example, also be mica paper, e.g. B. multi-layer silicone resin-impregnated mica paper.

A high-temperature plastic can be understood as a polymer material with high heat resistance. For example, the heat-resistant material 16 or the high-temperature plastic can comprise a, preferably aromatic, polyimide (e.g. Vespel). The heat-resistant material 16 or the high-temperature plastic can also include, for example, a polyamideimide, a polyether ketone and/or a polyether ether ketone. The high-temperature plastic can be a thermoplastic and/or a thermoset.

The degassing line 14 can be coated with the heat-resistant material 16 (see Figure 3A). For example, the degassing line 14 can have a base body (e.g. made of plastic and/or high-temperature plastic) to which the heat-resistant material 16 is applied as a coating. The coating can be applied to the entire base body or only in sections, e.g. B. in particularly temperature-exposed areas. For example, the coating can be arranged exclusively on a surface of the base body facing the respective degassing elements 12a. So the coating can e.g. B. be arranged on an inside of the hollow profile section 14a and / or the open profile section 14b. The coating can be homogeneous. Alternatively, the coating can be spatially structured. The coating can e.g. B. a first Have an area with a first thickness of the coating and a second area with a second thickness of the coating that is different from the first thickness. The degassing line 14 or the coating can therefore have at least two different layer thicknesses of the heat-resistant material 16.

The degassing line 14 can further comprise a molded part made of the heat-resistant material 16 (see Figures 3B and 3C). For example, the heat-resistant material 16 can be designed as a (e.g. pressed and/or cast) molded part (e.g. as a tube and/or profile element). In one embodiment, for example, the entire degassing line 14 (e.g. continuously) can be made of the heat-resistant material 16. For this purpose, the heat-resistant material 16 can be originally formed and/or reshaped in the form of the degassing line 14. For example, mica fragments can be pressed into a pipe structure using a synthetic resin (e.g. epoxy or a silicone resin) as a binder and then baked under pressure and temperature. Accordingly, the (entire) degassing line 14 can essentially consist of the heat-resistant material 16.

Furthermore, the electrical energy storage 10 can each have further of the aforementioned components. These can be designed as described above. The several of the aforementioned components can be offset from one another or repeatedly arranged in different positions. In one embodiment, the electrical energy storage 10 can be, for example, a multi-layer energy storage (not expressly shown).

For example, the electrical energy storage device 10 can have additional battery cells which are arranged in a further or offset position or plane compared to the aforementioned multiple battery cells 12. For example, the plurality of additional battery cells can be arranged offset in parallel (e.g. above or below) to the plurality of battery cells 12. The several additional battery cells can each have a further degassing element for cell degassing. Furthermore, the electrical energy storage 10 can have a further degassing line, which can fluidly connect the further degassing elements of the several further battery cells to one another. The further degassing line can also have the heat-resistant material (e.g. in the form of a coating). The further degassing line can be fluidly connected (e.g. across layers) to the aforementioned degassing line 14. Additionally or alternatively, the further degassing line can also be connected to a further outlet valve (e.g. a pressure relief valve). For example, the further Exhaust valve may be arranged on the housing 11. The housing 11 is preferably designed in several parts or modularly. For example, the housing 11 can have several, preferably frame-shaped, housing sections that are stacked, preferably one on top of the other. In a preferred embodiment, each of the housing sections has a corresponding outlet valve.

Although the invention has been described with reference to specific embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents substituted without departing from the scope of the invention. Accordingly, the invention is not intended to be limited to the embodiments disclosed, but is intended to include all embodiments that fall within the scope of the appended claims. In particular, the invention also claims protection for the subject matter and features of the subclaims, regardless of the claims referred to.

Reference symbol list

10 Electrical energy storage

11 housing

12 battery cell

12a degassing element

14 degassing line

14.1 Main line section

14.2 Connecting line section

14a hollow profile section

14b Open profile section

15 passage opening

16 Heat-resistant material

18 cover plate

18a passage

20 recording room

H vertical axis

L longitudinal axis

Q transverse axis

Claims

Patent claims

1. Electrical energy storage (10) for a motor vehicle, preferably commercial vehicle, comprising: a plurality of battery cells (12), each of which has a degassing element (12a) for cell degassing; and a degassing line (14) which fluidly connects the degassing elements (12a) of the plurality of battery cells (12) to one another; wherein the degassing line (14) has a heat-resistant material (16), namely a silicate and/or a high-temperature plastic

2. Electrical energy storage (10) according to claim 1, wherein: the heat-resistant material (16) has a melting temperature of at least 150 °C, preferably at least 250 °C, particularly preferably at least 400 °C.

3. Electrical energy storage (10) according to one of the preceding claims, wherein: the silicate comprises mica, preferably artificial mica; and/or the high-temperature plastic comprises a polyimide.

4. Electrical energy storage (10) according to one of the preceding claims, wherein the degassing line (14): is designed to collect substances emerging from the plurality of battery cells (12) via the degassing elements (12a) and preferably from the electrical energy storage (10). lead; and/or at least partially delimits a receiving space (20) for substances emerging from the respective degassing elements (12a).

5. Electrical energy storage (10) according to one of the preceding claims, wherein the degassing line (14) has: a hollow profile section (14a) with a plurality of through openings (15), preferably the plurality of through openings (15) each being aligned with the respective degassing elements (12a). are arranged; and/or an open profile section (14b), preferably a II, C and/or hat profile section, wherein the open profile section (14b) has a cross section that is open towards the respective degassing elements (12a).

6. Electrical energy storage (10) according to one of the preceding claims, wherein: the degassing line (14) has a base body, preferably made of plastic, to which the heat-resistant material (16) is applied as a coating.

7. Electrical energy storage (10) according to claim 6, wherein the coating: a) has a first region with a first thickness of the coating and a second region with a second thickness of the coating that is different from the first thickness; and/or b) is arranged on a surface of the base body facing the respective degassing elements (12a).

8. Electrical energy storage (10) according to one of the preceding claims, wherein: the heat-resistant material (16) is designed as a, preferably pressed and / or cast, molded part; and/or the degassing line (14) essentially consists of the heat-resistant material (16).

9. Electrical energy storage (10) according to one of the preceding claims, further comprising: a cover plate (18) which is arranged between the degassing line (14) and the plurality of battery cells (12) and which covers the plurality of battery cells (12), preferably for Protection of the several battery cells (12) from substances escaping from the respective degassing elements (12a).

10. Electrical energy storage (10) according to claim 9, wherein the cover plate (18): a) has a plurality of passages (18a), each of which is arranged correspondingly, preferably aligned, to the respective degassing elements (12a); and/or b) a side surface, preferably a top surface, of each of the plurality of battery cells (12) is covered; and/or c) together with the degassing line (14), a receiving space (20) is delimited for substances emerging from the respective degassing elements (12a). Electrical energy storage (10) according to one of the preceding claims, further comprising: at least one outlet valve, preferably arranged on a housing (11) of the electrical energy storage, which is fluidly connected to the degassing line (14), preferably for discharging the gases from the respective degassing elements (12a) escaping substances from the housing (11). Electrical energy storage (10) according to one of the preceding claims, wherein: the plurality of battery cells (12) are arranged in the form of at least two battery cell stacks, which preferably each have the same stacking direction; the degassing line (14) has at least two straight main line sections (14.1), each of which is assigned to one of the at least two battery cell stacks; and the degassing line (14) has at least one connecting line section (14.2) which connects the two straight main line sections (14.1) to one another. Electrical energy storage (10) according to claim 12, wherein: the at least one connecting line section (14.2) extends at least in sections above or below the two straight main line sections (14.1). Electrical energy storage (10) according to one of the preceding claims, further comprising: at least one sealing element which is arranged between the degassing line (14) and the plurality of battery cells (12). Motor vehicle, preferably commercial vehicle, having an electrical energy storage (10) according to one of the preceding claims.