Battery for a motor vehicle

Abstract

The invention relates to a battery for a motor vehicle, comprising at least the following components: - a plurality of battery cells, - a guide channel; - an optical fiber arranged in the guide channel for transmitting an optical signal; and - an evaluation unit connected to the guide channel for outputting and recording light signals, wherein where at least a spatially resolved temperature along the optical fiber can be determined using the evaluation unit. A battery with temperature measurement via an optical fiber is proposed.

Description

[0001] The invention relates to a battery for a motor vehicle, and to a manufacturing method for such a battery.

[0002] Batteries, such as traction batteries, are a familiar feature in industrial applications, particularly in motor vehicles. Temperature management plays a crucial role during both charging and discharging. In industrial practice, this involves positioning individual temperature sensors at carefully selected measuring points during the battery's design. These sensors are typically placed at points considered to be potentially hot or cold.

[0003] The selection of measuring points must be made during the design phase and is limited to a few points, usually two or three measuring points per battery module. Furthermore, creating redundancies is costly in case one of the temperature sensors malfunctions or is damaged.

[0004] DE 10 2011 002 841 A1 describes an electrochemical energy storage device comprising a cell arrangement with at least one electrochemical cell, temperature sensing means which provide at least one piece of information about the temperature of at least one electrochemical cell, wherein the temperature sensing means include at least one fiber optic sensor.

[0005] DE 10 2012 214 441 B4 describes a method for detecting mechanical state variables, comprising the following steps: providing a fiber optic sensor with at least two cores made of a first material with a first refractive index and a cladding surrounding the cores made of a second material with a second refractive index, wherein at least one fiber Bragg grating is incorporated into each core and the fiber Bragg gratings are arranged at different locations along the longitudinal extent in at least a first longitudinal section of the fiber optic sensor, connecting the fiber optic sensor to a mechanical component, coupling light into at least two cores, detecting the light reflected by the fiber Bragg gratings, and evaluating the intensity in predefinable wavelength ranges.

[0006] DE 10 2014 219 720 B4 describes a battery with a battery housing and at least one battery cell and at least one fiber optic sensor, which has at least one waveguide with a core and a cladding surrounding the core, wherein at least one first fiber Bragg grating is incorporated in the core, which is mechanically coupled to the battery housing and / or the battery cell, and at least one second fiber Bragg grating is incorporated in the core, which is mechanically decoupled from the battery housing and the battery cell.

[0007] US 2022 O 412 810 A1 describes a temperature measurement device for fiber optic cables applied to a multi-stage power module, such as a battery storage system. The temperature measurement device is applied to a power device comprising multiple power modules. The temperature measurement device includes: fiber optic cable measuring units provided in the respective power modules; fiber optic cables inserted and installed in the respective fiber optic cable measuring units; and a control unit connected to one end of the fiber optic cables to measure the temperature.

[0008] Based on this, the present invention aims to overcome, at least partially, the disadvantages known from the prior art. The features of the invention are defined in the independent claims, for which advantageous embodiments are shown in the dependent claims. The features of the claims can be combined in any technically meaningful way, whereby the explanations in the following description and features from the figures, which comprise supplementary embodiments of the invention, can also be used.

[0009] The invention relates to a battery for a motor vehicle, comprising at least the following components: - a plurality of battery cells, - a guide channel; - an optical fiber arranged in the guide channel for transmitting an optical signal; and - an evaluation unit connected to the guide channel for outputting and recording light signals, wherein at least a spatially resolved temperature along the optical fiber can be determined by means of the evaluation unit.

[0010] Unless explicitly stated otherwise, ordinal numbers used in the preceding and following descriptions serve solely for unambiguous differentiation and do not indicate any order or ranking of the components referred to. An ordinal number greater than one does not necessarily imply the presence of another such component.

[0011] A battery for a motor vehicle is proposed here. Preferably, the battery comprises a plurality of battery modules. Preferably, the battery is a traction battery of a motor vehicle, particularly preferably of a purely electric motor vehicle (BEV [Battery Electric Vehicle]) or a hybrid vehicle.

[0012] Such a battery has a plurality of battery cells, a guide channel, an optical fiber and an evaluation unit.

[0013] Preferably, each battery module comprises a plurality of battery cells. For example, each battery module has a separate guide channel with an optical fiber, which is connected to a separate evaluation unit. Alternatively, a plurality of battery modules have a common guide channel with a common optical fiber, which is connected to a common evaluation unit.

[0014] For example, the guide channel is at least partially an integral part of a battery housing and / or module housing of the battery or battery module. In such an embodiment, the guide channel is produced by a casting process and / or by machining, for example, milling and / or drilling. Alternatively or additionally, the guide channel is formed separately, for example, using pipes and / or hoses.

[0015] An optical fiber is suitable for transmitting an optical signal. For example, an optical fiber is a glass fiber. For example, a battery contains a fiber bundle with multiple optical fibers.

[0016] This evaluation unit is optically connected to the optical fiber or fiber bundle. Thus, an optical signal can be output to and received from the fiber using the evaluation unit.

[0017] Preferably, the evaluation unit is designed to detect the Raman backscatter of the output light signal. Preferably, the evaluation unit is designed to determine a location-dependent temperature based on the detected Raman backscatter, for example, based on the intensity of the Raman backscatter in the anti-Stokes band and / or Stokes band.

[0018] For example, the evaluation unit includes an OFDR Raman temperature sensor (OFDR [Optical Frequency Domain Reflectometry]).

[0019] The evaluation unit allows for the determination of at least one, preferably a plurality of, spatially resolved temperatures along the optical fiber.

[0020] The proposed battery enables simple temperature measurement at multiple measuring points.

[0021] In an advantageous embodiment of the battery, it is further proposed that the battery has a plurality of optical fibers arranged parallel to each other, wherein The optical fibers are designed and arranged to measure redundantly identical measurement points.

[0022] According to this embodiment, the battery has a plurality of optical fibers or fiber bundles. The plurality of optical fibers or fiber bundles are arranged parallel to each other in a common or separate, parallel guide channels.

[0023] The fibers or fiber bundles are arranged so close together that they redundantly capture the same measurement points. In other words, the fibers are arranged so close together that the measurement points have the same temperature, except for acceptable tolerance deviations. For example, the fibers or fiber bundles are arranged adjacent to each other.

[0024] In a further advantageous embodiment of the battery, it is proposed that the optical fiber is designed as a loop and that the measuring points are redundantly connected to the evaluation unit by means of a forward path and a return path.

[0025] According to this embodiment, the optical fiber or fiber bundle is configured as a loop. For example, two optical fibers or fiber bundles, as described above, are connected to each other at one end opposite the evaluation unit to form a loop. Thus, the outward path of the loop to the end opposite the evaluation unit provides redundancy for the return path from that end. In such a case, redundancy is also created in the event of a fiber break.

[0026] In a further advantageous embodiment of the battery, it is proposed that the battery has a plurality of evaluation units.

[0027] According to this embodiment, the battery has a plurality of evaluation units or at least parts of the evaluation unit. For example, the evaluation unit has a signal transmitter for outputting the light signal and a receiver for detecting the light signal. For example, the battery has a plurality of signal transmitters and / or a plurality of receivers. For example, each battery module has a plurality of evaluation units or signal transmitters and / or receivers. The evaluation units or receivers and / or signal transmitters are designed to be redundant to one another, so that redundancy against the failure of such a unit and / or the possibility of verifying the measured values ​​of the individual units is created. Preferably, the optical fiber or plurality of optical fibers are connected to several redundant evaluation units or receivers and / or signal transmitters.

[0028] In a further advantageous embodiment of the battery, it is proposed that the evaluation unit or a plurality of evaluation units is designed to output a plurality of different measurement signals in order to measure the measurement points redundantly, and The evaluation unit or a plurality of evaluation units is designed to receive the majority of light signals and to evaluate the measuring points redundantly.

[0029] According to this embodiment, light signals with different frequencies can be output by means of one or more evaluation units or signal transmitters, thus creating redundancy for the frequency range.

[0030] Accordingly, the evaluation unit or the plurality of evaluation units or receiving units is designed to receive and evaluate the majority of light signals.

[0031] The guide channel has a plurality of sub-segments, the sub-segments being connected to each other in a compressed airtight manner by means of pipe grouting and / or seals.

[0032] The embodiment proposed here enables a compressed air-tight guide channel, which is cost-effective to manufacture and allows for the simple insertion of an optical fiber.

[0033] For example, the sub-segments are pipes, hoses, or integral channels within a battery housing, module housing, and / or cell housing. The sub-segments are connected to each other in a compressed airtight manner by means of pipe crimping, gluing, welding, soldering, and / or gaskets.

[0034] According to another aspect, a manufacturing process for a battery is proposed, comprising the following steps: a. Providing a battery with a guide channel; and b. By means of compressed air, blowing an optical fiber into the guide channel.

[0035] A manufacturing process for a battery is proposed here in which the optical fiber is blown into a guide channel of the battery using compressed air. Preferably, the evaluation unit is then connected to the optical fiber.

[0036] In step a.0, a plurality of sub-segments are connected to form a guide channel in a compressed air-tight manner.

[0037] According to this embodiment, the sub-segments of the guide channel are connected to each other in a compressed air-tight manner before the fiber is blown in. Complete airtightness is not required. In this context, "compressed air-tight" means that the seal is sufficient to allow the optical fiber to be conveyed through the entire guide channel using compressed air in the subsequent step. For example, several sub-segments integrally formed in the battery housing, cell housing, and / or module housing are connected to each other or to pipe segments and / or hose segments, or several pipe segments or hose segments are connected to each other.

[0038] For example, the sub-segments are pressed together, soldered, welded, glued and / or fitted with seals.

[0039] In an advantageous embodiment of the manufacturing process, it is further proposed that the manufacturing process for producing a battery according to an embodiment as described above is set up.

[0040] The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way limited by the purely schematic drawings, although it should be noted that the drawings are not dimensionally accurate and are not suitable for defining size relationships. It is illustrated in Fig. 1: A schematic representation of a battery with an optical fiber for temperature measurement in a perspective view; Fig. 2: a schematic representation of an optical fiber in a guide channel; Fig. 3: a schematic representation of an optical fiber with two evaluation units; Fig. 4: a schematic representation of two optical fibers with an evaluation unit; Fig. 5: a schematic representation of an optical fiber as a loop with an evaluation unit; and Fig. 6: A motor vehicle in a schematic top view.

[0041] In Fig. Figure 1 is a schematic representation of a battery 1 with an optical fiber 5 for temperature measurement, shown in a perspective view. The battery 1 comprises a plurality of battery cells 3, three of which are shown here as an example, and a guide channel 4, which runs along a predetermined path between or over the battery cells 3. Exemplary measuring points 7 are indicated along the guide channel 4, at which the temperature of the battery cells 3 is measured by means of an evaluation unit 6 (see Figure 1). Fig. 3) is measurable.

[0042] The guide channel 4 is, for example, integrally formed in a cell housing of the battery cells 3. The guidance of the guide channel 4 is shown here as an example and covers the battery cells 3 over a large area.

[0043] For example, battery 1 is designed as a traction battery 1 of a motor vehicle 2.

[0044] In Fig. Figure 2 shows a schematic representation of an optical fiber 5 in a guide channel 4. A fiber 5, for example an optical fiber, is arranged within the guide channel 4 and is blown into the guide channel 4 along an injection direction 13. Preferably, the fiber 5 can be blown into the guide channel 4 using compressed air. For example, a guide head (not shown) is arranged at one end of the fiber 5 so that it moves the fiber 5 through the guide channel 4 along the injection direction 13.

[0045] For example, a guide channel 4 comprises a plurality of sub-segments which are connected to each other in a compressed airtight manner for this purpose.

[0046] In Fig. Figure 3 shows a schematic representation of an optical fiber 5 with two evaluation units 6. In this embodiment, a splitter 14 is arranged outside the battery 1, at which the optical fiber 5 is divided into two paths, so that each of the two paths is connected to an evaluation unit 6. Each evaluation unit 6 comprises a signal transmitter 11 and a receiver 12. The light signal is transmitted through the optical fiber 5 and received by the receiver 12 to measure the temperature at measuring points 7 within the battery 1 with spatial resolution. It should be noted that the optical fiber 5 can also be implemented as a fiber bundle.

[0047] By means of the several evaluation units 6 or signal generators 11, light signals with different frequencies are generated by (as shown here, one) or several (compare Fig. 4 and Fig. 5) optical fibers 5 output, so that redundancy for the frequency range is created with the embodiment proposed here.

[0048] In Fig. Figure 4 shows a schematic representation of two optical fibers 5 with an evaluation unit 6. In this embodiment, compared to the embodiment in Fig. Figure 3 shows only an evaluation unit 6, with, for example, a signal transmitter 11 and a receiver unit 12. The evaluation unit 6 is connected to two optical fibers 5, which run within a battery 1, thus providing redundancy in case of breakage or loss of one optical fiber 5.

[0049] In Fig. Figure 5 shows a schematic representation of an optical fiber 5 as a loop 8 with an evaluation unit 6. In this embodiment, the optical fiber 5 or fiber bundle is configured as a loop 8. For example, two optical fibers 5 or fiber bundles are connected to each other at one end opposite the evaluation unit 6, forming a loop 8, as described above. Thus, the forward path 9 of the loop to the end opposite the evaluation unit 6 provides redundancy for the return path 10 from this end. In such a case, redundancy is also created in the event of a fiber break, even if the fibers 5 are not completely redundantly connected to each other on the forward path 9 and the return path 10.

[0050] In Fig. 6 is a motor vehicle 2 with a battery 1, according to Fig.Figure 1 shows a schematic top view. The motor vehicle 2 comprises (here optionally two) electric drive motors 15, one on a front axle and one on a rear axle of the motor vehicle 2. The rear electric drive motor 15 is connected to two drive wheels 18 on the left and right via a transmission gearbox 16 and a differential 17, transmitting torque. Inside the traction battery 1, a guide channel 4 with an optical fiber 5 and an evaluation unit 6 (not shown here) is arranged.

[0051] Optionally, a second electric drive motor 15 is arranged in the front area of ​​the vehicle 2, which is connected to further drive wheels 18 on the left and right, transmitting torque. Thus, (optionally) all four wheels of the vehicle 2 are configured as drive wheels 18. Alternatively, a purely rear-wheel drive or a purely front-wheel drive is provided with one or more drive motors 15.

[0052] The electric drive motors 15 can be supplied with electrical power by means of the battery 1. Thus, a drive torque can be converted into a propulsion of the motor vehicle 2 by means of the electric drive motors 15 via the drive wheels 18.

[0053] A battery with temperature measurement via an optical fiber is proposed. Reference symbol list 1 battery 2 motor vehicles 3 battery cells 4 guide channel 5 fiber 6 evaluation unit 7 measuring point 8 loops 9 Outbound leg 10 Return leg 11 Signal transmitters 12 receiving units 13. Blowing direction 14 switches 15 electric drive motor 16 transmission gears 17 Differential 18 drive wheel

Claims

Battery (1) for a motor vehicle (2), comprising at least the following components: - a plurality of battery cells (3), - a guide channel (4); - an optical fiber (5) arranged in the guide channel (4) for transmitting an optical signal; and - an evaluation unit (6) connected to the guide channel (4) for outputting and receiving light signals, wherein at least a spatially resolved temperature along the optical fiber (5) can be determined by means of the evaluation unit (6), wherein the guide channel (4) comprises a plurality of sub-segments, and wherein the sub-segments are connected to each other in a compressed airtight manner by means of pipe crimping, gluing, welding, soldering and / or sealing. Battery (1) according to claim 1, wherein the battery (1) has a plurality of optical fibers (5) arranged parallel to each other, wherein the optical fibers (5) are designed and arranged to measure redundantly identical measuring points (7). Battery (1) according to claim 1 or claim 2, wherein the optical fiber (5) is formed as a loop (8) and the measuring points (7) are redundantly connected to the evaluation unit (6) by means of a forward path (9) and a return path (10). Battery (1) according to one of the preceding claims, wherein the battery (1) has a plurality of evaluation units (6). Battery (1) according to one of the preceding claims, wherein the evaluation unit (6) or a plurality of evaluation units (6) is designed to output a plurality of different measurement signals in order to measure the measurement points (7) redundantly, and the evaluation unit (6) or a plurality of evaluation units (6) is designed to receive the plurality of light signals and to evaluate the measurement points (7) redundantly. A manufacturing method for a battery (1) comprising the following steps: a. providing a battery (1) with a guide channel (4); and b. using compressed air, blowing an optical fiber (5) into the guide channel (4), wherein the manufacturing method for producing a battery (1) is set up according to any one of claims 1 to 5.

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