Battery pack with optical fiber sensor

Abstract

A battery pack with an optical fiber sensor comprises a battery module which comprises a plurality of battery cells and a plurality of busbars, the plurality of battery cells are arranged at least along a first direction, and output poles of adjacent battery cells arranged along the first direction are connected through the busbars; a battery box; and the optical fiber sensors take the battery cells coaxially arranged along the first direction as a column, one optical fiber sensor is arranged on each column of battery cells along the first direction, the optical fiber sensors are connected to the plurality of busbars of the battery cells in the column, and each optical fiber sensor comprises a plurality of optical fiber gratings which are arranged in one-to-one correspondence with the plurality of battery cells in the column. By reasonably arranging the optical fiber sensors, the real-time temperature of each battery cell can be accurately acquired, the accuracy of temperature acquisition is improved, the probability of thermal runaway of the battery pack is reduced, and meanwhile, compared with an existing scheme adopting an acquisition wire harness, the acquisition cost is reduced, the labor is saved, the installation and maintenance are convenient, and the interior of the battery pack is neat and attractive.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery pack with an optical fiber sensor. Background Art

[0002] As an important component of electrochemical energy storage systems, battery packs will play an increasingly important role in grid modernization and renewable energy development, so their safety and reliability are crucial. As the number of cells in a battery pack increases, it becomes particularly important to monitor the temperature of the cells to prevent thermal runaway. At present, the monitoring of the temperature of the cells in a battery pack mainly has the following problems:

[0003] 1. More temperature collection points: Each battery cell needs to monitor the temperature. As the number of battery cells increases, the number of temperature collection points in the battery pack also increases;

[0004] 2. Collection harness increase: Figure 1 It is a structural schematic diagram of an existing battery pack. Figure 2 This is a schematic diagram of the arrangement of the collection harness in an existing battery pack, see Figure 1 and Figure 2 The existing solution is to connect a collection harness A to each temperature collection point to monitor the corresponding battery cell temperature. However, as the number of temperature collection points increases, the number of harnesses also increases accordingly. The increase in the number of harnesses means that the risk of failure of a single collection point also increases;

[0005] 3. Increased costs and inconvenient installation and maintenance: A large number of collection harnesses A will increase the difficulty of installation and maintenance. The materials and installation costs selected for the collection harnesses will increase the overall cost of the battery pack.

[0006] 4. The internal appearance is affected: After a large number of wiring harnesses are fixed, the internal aesthetics of the battery pack will be affected.

[0007] In order to reduce costs, some manufacturers have reduced the number of temperature collection points in the battery pack. However, reducing the number of temperature collection points will lead to the following problems:

[0008] 1. Decreased temperature collection accuracy: Reducing the number of collection points means that it is impossible to understand the real-time temperature of each battery cell in real time;

[0009] 2. Increased risk of thermal runaway: Local overheating cannot be detected in time, increasing the risk of thermal runaway and other failures in the battery pack. Utility Model Content

[0010] In view of this, the purpose of this application is to provide a battery pack with an optical fiber sensor, which can not only meet the needs of high-precision temperature acquisition in the battery pack, but also reduce costs and improve reliability and aesthetics.

[0011] The present application provides a battery pack with an optical fiber sensor, comprising: a battery module, comprising a plurality of battery cells and a plurality of bus bars, wherein the plurality of battery cells are arranged along at least a first direction, and output poles of adjacent battery cells arranged along the first direction are connected via a bus bar; a battery box, wherein the battery module is arranged inside; and an optical fiber sensor, wherein a group of battery cells arranged along the first direction constitutes a column, an optical fiber sensor is arranged on each column of battery cells along the first direction, the optical fiber sensor is connected to a plurality of bus bars in the column of battery cells, and the optical fiber sensor comprises a plurality of optical fiber gratings arranged in a one-to-one correspondence with the plurality of battery cells in the column of battery cells.

[0012] In some optional embodiments, the optical fiber sensor is fixedly connected to the bus by gluing.

[0013] In some optional implementations, the length of the optical fiber sensor is greater than or equal to the length of the battery cell column in which it is located.

[0014] In some optional embodiments, the distance between adjacent fiber gratings is consistent with the distance between corresponding adjacent battery cores in the first direction.

[0015] In some optional embodiments, in the battery module, a plurality of battery cells are arranged in a rectangular array along a first direction and a second direction perpendicular to the first direction.

[0016] In some optional embodiments, the multiple battery cells in the battery module are square battery cells of the same model.

[0017] In some optional embodiments, the battery module further includes two end plates and at least one tie band, the two end plates are arranged opposite to each other and clamp the multiple battery cells therebetween, and the two end plates and the multiple battery cells are bound and fixed by the tie band.

[0018] In some optional embodiments, the battery box includes a bottom plate and an upper cover, the bottom plate is a liquid cooling plate, a fixing groove for accommodating the battery module is provided on the bottom plate, and the upper cover is assembled with the bottom plate to form a closed chamber for accommodating the battery module.

[0019] In some optional embodiments, the battery pack may further include a front panel, which is mounted on the battery box and provided with a conversion connector, the interior of the conversion connector is connected to one end of the optical fiber sensor, and the exterior is used to connect to the optical fiber demodulation device.

[0020] Furthermore, the battery pack also includes an optical fiber demodulation device, and the optical fiber demodulation device is connected to the conversion connector.

[0021] The battery pack with fiber optic sensors provided in the present application can accurately collect the real-time temperature of each battery cell in the battery pack by reasonably arranging the fiber optic sensors, thereby improving the accuracy of temperature collection and reducing the probability of thermal runaway of the battery pack. At the same time, compared with the existing solution using a collection harness, it reduces the collection cost, saves labor, and facilitates installation and maintenance, and the interior of the battery pack is neat and beautiful. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 The figure is a schematic diagram of the structure of an existing battery pack.

[0024] Figure 2 The figure is a schematic diagram of the arrangement of the collection harness in an existing battery pack.

[0025] Figure 3 A schematic diagram of the three-dimensional structure of a battery pack with an optical fiber sensor provided in an embodiment of the present application.

[0026] Figure 4 A schematic top view of a battery pack with an optical fiber sensor provided in an embodiment of the present application.

[0027] Figure 5 A schematic diagram of the structure of an optical fiber sensor provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The specific embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the description of the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0029] In the description of this application, unless otherwise clearly specified and limited, the terms "connection", "setting", "installation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be that two elements are internally connected. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] The terms "upper", "lower", "left", "right", "front", "back", "center", "top", "bottom", "inside", "outside", "vertical", "horizontal", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship commonly placed when the product of the application is used. They are only for the convenience of description and simplified description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0031] The terms “first”, “second”, “third”, etc. are merely used to distinguish elements of similar nature, and do not indicate or imply relative importance or a particular order, unless expressly specified and limited otherwise.

[0032] The terms "comprises," "includes," "has," or any other variation thereof, are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0033] The term "plurality" means two or more (including two).

[0034] The term "and / or" is merely a description of the association relationship between associated objects, indicating that three possible relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0035] The terms "one embodiment", "as an example", "in one implementation", etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example may be included in at least one embodiment or example of the present application. Schematic representations of such terms do not necessarily refer to the same embodiment, nor are they independent or alternative embodiments that are mutually exclusive with other embodiments. In the absence of conflict, the embodiments in the present application and the features in the embodiments may be combined in a suitable manner.

[0036] Figure 3 A schematic diagram of the three-dimensional structure of a battery pack with an optical fiber sensor provided in an embodiment of the present application. Figure 4 A schematic top view of a battery pack with an optical fiber sensor provided in an embodiment of the present application. Figure 3 and Figure 4The embodiment of the present application provides a battery pack with an optical fiber sensor, the battery pack comprising at least one battery module 10, a battery box 20, and at least one optical fiber sensor 30. Each part is described in detail below.

[0037] The battery module 10 may include a plurality of battery cells 11 and a plurality of bus bars 12. The plurality of battery cells 11 are arranged in series, parallel or mixed connection. Further, a single battery module 10 may constitute a battery pack, and a plurality of battery modules 10 may also constitute a battery pack in series, parallel or mixed connection.

[0038] The battery cell 11 may be, but is not limited to, a rechargeable battery such as a lithium polymer battery, a lithium ion battery, a lead-acid battery, a nickel-cadmium battery, a nickel-metal hydride battery, etc. The shape of the battery cell 11 may be, for example, a cube or a cylinder, and the present application does not specifically limit the shape of the battery cell 11.

[0039] The multiple battery cells 11 in the battery module 10 are arranged at least along the first direction, and can also be arranged in a rectangular array along the first direction and a second direction perpendicular to the first direction. If the multiple battery cells 11 in the battery module 10 are arranged along the first direction, the battery module 10 includes only one column of battery cells. If the multiple battery cells 11 in the battery module 10 are arranged along the first direction and the second direction, the battery module 10 includes at least two columns of battery cells arranged side by side. The multiple battery modules 10 can be arranged along the first direction and / or the second direction.

[0040] In one embodiment, the multiple battery cells 11 in the battery module 10 are square battery cells of the same model and are arranged in a stacked manner.

[0041] The number and arrangement of the battery modules 10 and battery cells 11 shown in the figure are schematic. For example, the number of battery modules 10 can be 4 as shown in the figure, and the 4 battery modules 10 can be arranged in a 2*2 rectangular array along the first direction and the second direction; the number of battery cells 11 in each battery module 10 can be 26 as shown in the figure, and the 26 battery cells 11 can be arranged in a 13*2 rectangular array along the first direction and the second direction. Among them, the number of battery modules 10 and battery cells 11 can be adaptively adjusted according to different application scenarios of the battery, and this application does not specifically limit the number of battery cells 11 and battery modules 10.

[0042] The busbar 12 is a conductive component that connects the battery cells 11 in the battery module 10, and is usually formed in one piece from a metal material with good conductivity, such as copper or aluminum. The busbar 12 connects the output poles of the battery cells 11 to connect the battery cells 11 in series to form a conduction loop, thereby ensuring that electric energy is smoothly transmitted inside the battery module 10, allowing each battery cell 11 to work stably and extending the service life of the battery. For each column of battery cells in the battery module 10, two columns of buses are provided along its width direction, and each column of buses includes a plurality of buses 12 arranged along the length direction of the battery module 10, and the corresponding buses 12 in the two columns of buses are staggered to achieve the series connection of the battery cells 11 in each column of battery cells in the battery module 10. For example Figure 4 As shown, in each battery module 10 , the busbars 12 located at the lower side of each column of battery cells are staggered from the busbars 12 located at the upper side in the length direction of the battery module 10 .

[0043] The position of the busbar 12 is set according to the position of the output pole of the battery cell 11 .

[0044] In one embodiment, if Figure 3 As shown, the output poles of each battery cell 11 in the battery module 10 are arranged on the top thereof, and the output poles of adjacent battery cells 11 arranged in a first direction are connected through at least one bus bar 12 arranged on the top. Among them, a single bus bar 12 can be in the form of a flat sheet, which is integrally formed and can be fixedly connected to the output pole of the battery cell 11 by welding.

[0045] The battery module 10 may further include two end plates 13 disposed opposite to each other. The two end plates 13 are respectively disposed at two ends of the corresponding battery module 10 in the length direction, and play a role in fixing and protecting the multiple battery cells 11.

[0046] In one embodiment, if Figure 3 As shown, the battery module 10 may further include at least one strap 14 , which may clamp and fix the plurality of battery cells 11 between the two end plates 13 , thereby bundling and fixing the two end plates 13 and the plurality of battery cells 11 .

[0047] A plurality of battery modules 10 may be disposed in the battery box 20 , and the battery box 20 plays a role in protecting and sealing the plurality of battery modules 10 therein as a whole.

[0048] The battery box 20 may include a bottom plate 21 and an upper cover (not shown in the figure). The bottom plate 21 supports the battery module 10. The bottom plate 21 may be provided with an auxiliary structure for positioning and ensuring the stable installation of the battery module 10. For example, the bottom plate 21 is provided with a fixing groove corresponding to each battery module 10. By placing each battery module 10 into the corresponding fixing groove, the installation position of each battery module 10 can be determined. The bottom plate 21 can also cool and dissipate heat for the battery cell 11. Exemplarily, the bottom plate 21 is a liquid cooling plate. The upper cover can be combined with the bottom plate 21 to form a closed chamber of the battery box 20. Correspondingly, the edge of the bottom plate 21 can be provided with a buckle 211 for connecting the upper cover.

[0049] In one embodiment, the battery module 10 is fixed on the bottom plate 21 , and the upper cover has a cavity that can accommodate the battery module 10 . The upper cover is assembled with the bottom plate 21 by snapping to form the battery box 20 .

[0050] The optical fiber sensor 30 is mainly composed of an optical fiber and an optical fiber grating 31. The optical fiber is a thin and soft material that can transmit optical signals. The optical fiber grating 31 is a diffraction grating formed by axially periodically modulating the refractive index of the optical fiber core by a certain method. It is a passive filter device that can modulate light through the interference effect. When the optical signal passes through the optical fiber grating 31, its specific physical quantity (such as temperature, pressure, tension, etc.) will change the characteristics of the optical fiber or the optical fiber grating 31, thereby changing the characteristics of the optical signal. By detecting these changes, the measurement and monitoring of physical quantities in the environment can be achieved.

[0051] In the embodiment of the present application, the optical fiber sensor 30 mainly utilizes the influence of temperature on the characteristics of the optical fiber, and measures the temperature of the battery cell 11 in the battery pack through the change of the optical signal caused by thermal radiation. The number, structure, and arrangement of the optical fiber sensors 30 must ensure that the real-time temperature of each battery cell 11 in the battery pack can be monitored, that is, a temperature collection point must be set for each battery cell 11 to ensure the accuracy of the collected temperature and reduce the probability of thermal runaway of the battery pack. At the same time, the distribution of all temperature collection points must be optimized to improve reliability and aesthetics, and reduce costs. The number, structure, and arrangement of the optical fiber sensors 30 are described in detail below.

[0052] In the battery pack, each group of battery cells 11 arranged along the first direction is a column, and N columns of battery cells arranged along the second direction can be provided in the battery pack, where N is a positive integer. The number of columns of battery cells 11 shown in the figure is schematic, for example, the number of columns of battery cells 11 can be 4 columns as shown. The present application does not specifically limit the number of columns of battery cells 11 and the distance between two adjacent columns of battery cells.

[0053] One optical fiber sensor 30 is arranged on each column of cells along the first direction, that is, N optical fiber sensors 30 can be arranged in the battery pack. The number of optical fiber sensors 30 shown in the figure is schematic, for example, there can be 4 optical fiber sensors 30 as shown in the figure.

[0054] Figure 5 A schematic diagram of the structure of an optical fiber sensor 30 provided in an embodiment of the present application.

[0055] The length of the optical fiber sensor 30 is greater than or equal to the length of the cell array in which it is located. Figure 5 As shown, the optical fiber sensor 30 includes a plurality of optical fiber gratings 31 arranged on an optical fiber. The number of the optical fiber gratings 31 is consistent with the number of the battery cells 11 in the battery cell column, and the positions of the plurality of optical fiber gratings 31 correspond to the positions of the plurality of battery cells 11 in the battery cell column, so that each optical fiber grating 31 is a collection point.

[0056] The distance between adjacent fiber gratings 31 is consistent with the distance between corresponding adjacent battery cores 11 in the first direction, but this does not require that the distance between adjacent fiber gratings 31 must be the same, but it is adaptively adjusted according to the distance between corresponding adjacent battery cores 11. The reason is that Figure 4 As shown, the distance d between adjacent cells 11 in the same row in the battery module 10 is 1 Generally, the distance d between the cells 11 at the adjacent ends of the adjacent battery modules 10 in the same row is the same as that between the cells 11 at the adjacent ends of the adjacent battery modules 10 in the same row. 2 Will be greater than the former.

[0057] Since the optical fiber itself is an insulating material, the optical fiber sensor 30 can be set on the surface of the battery cell 11 in the battery cell column. In one embodiment, the optical fiber sensor 30 is fixedly connected to the bus 12 on the top of each battery cell 11 in the battery cell column by gluing. The gluing fixation method has the advantages of being simple, fast, low-cost, and highly adaptable. It can avoid electrical contact problems that may occur when using metal clamps or bolts and other fixings, reduce potential interference and failure risks, improve the seismic resistance of the optical fiber sensor 30, reduce the error caused by vibration during the operation of the battery, and reduce the impact on the appearance of the battery module 10, ensuring the aesthetics of the interior of the battery pack.

[0058] A battery pack with an optical fiber sensor provided in an embodiment of the present application may further include a front panel 40 and an optical fiber demodulation device 50 .

[0059] The front panel 40 is usually mounted on the battery box 20, but is not a part of the battery box 20. The front panel 40 is usually provided with electrical components.

[0060] In one embodiment, a conversion connector 41 is provided on the front panel 40, and the interior of the conversion connector 41 is connected to one end of the optical fiber sensor 30, such as Figure 4 As shown, one end of each optical fiber sensor 30 close to the conversion connector 41 is connected to the conversion connector 41, and the outside of the conversion connector 41 is used to connect the optical fiber demodulation device 50. Among them, the other end of the optical fiber sensor 30 can be connected to the tail end of the battery pack. For example, the other end of the optical fiber sensor 30 is fixedly connected to the bus 12 on the top of the battery cell 11 at the corresponding position by gluing.

[0061] The functions of the optical fiber demodulation device 50 mainly include demodulation, amplification, processing and display of optical signals, as well as storage and transmission of data. When in use, the optical fiber demodulation device 50 can be connected to the conversion connector 41 on the front panel 40 through an optical fiber connecting line, so that the optical fiber demodulation device 50 can transmit optical signals to the optical fiber sensor 30, and receive optical signals reflected back by each optical fiber grating 31 of the optical fiber sensor 30, and then process the optical signals, convert the optical signals into electrical signals, and finally convert them into temperature physical quantities, so as to realize temperature monitoring and fault location of each battery core 11.

[0062] In order to better understand the battery pack with optical fiber sensor provided in the embodiment of the present application, an assembly method of the battery pack is provided here: when making the battery module 10, the multiple battery cells 11 arranged therebetween are clamped by two end plates 13 arranged opposite to each other, the adjacent battery cells 11 are connected by welding the busbar 12 on the output pole, and the two end plates 13 and the multiple battery cells 11 are bound and fixed by the tie band 14 to form the battery module 10. After placing the multiple battery modules 10 on the bottom plate 21 of the battery box 20 and fixing them, each optical fiber sensor 30 is placed on the top of each battery cell 11 of the column of battery cells to be set, and the optical fiber sensor 30 is in contact with the busbar 12, and then the position of each optical fiber grating 31 of the optical fiber sensor 30 corresponds to the position of each battery cell 11 of the column of battery cells, and then the optical fiber sensor 30 is fixed on the busbar 12 by applying glue, and after the glue is cured, one end of the optical fiber sensor 30 is connected to the conversion connector 41 of the front panel 40. After all the optical fiber sensors 30 are installed, the upper cover is installed to form the battery box 20. Finally, the optical fiber demodulation device 50 is connected to the conversion connector 41 of the front panel 40 to form a battery pack with an optical fiber sensor.

[0063] In summary, a battery pack with an optical fiber sensor provided in an embodiment of the present application can accurately collect the real-time temperature of each battery cell 11 in the battery pack by reasonably arranging the optical fiber sensor 30, thereby improving the accuracy of the collected temperature and reducing the probability of thermal runaway of the battery pack. At the same time, compared with the existing solution using a collection harness, it reduces the collection cost, saves labor, and facilitates installation and maintenance, and the interior of the battery pack is neat and beautiful.

[0064] The above description is only a specific implementation mode of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the field can easily think of various changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A battery pack with an optical fiber sensor, characterized in that: include: A battery module (10) comprises a plurality of battery cells (11) and a plurality of bus bars (12). The plurality of battery cells (11) are arranged at least along a first direction, and the output poles of the adjacent battery cells (11) arranged along the first direction are connected via the bus bar (12); A battery box (20) having the battery module (10) arranged therein; as well as The optical fiber sensor (30) is a group of electric cores (11) arranged along the first direction as a row, and one optical fiber sensor (30) is arranged on each row of electric cores (11) along the first direction. The optical fiber sensor (30) is connected to the plurality of bus bars (12) in the row of electric cores, and the optical fiber sensor (30) includes a plurality of optical fiber gratings (31) arranged in a one-to-one correspondence with the plurality of electric cores (11) in the row of electric cores.

2. The battery pack with optical fiber sensor according to claim 1, characterized in that: The optical fiber sensor (30) is fixedly connected to the bus bar (12) by gluing.

3. The battery pack with optical fiber sensor according to claim 1, characterized in that: The length of the optical fiber sensor (30) is greater than or equal to the length of the battery cell row in which it is located.

4. The battery pack with optical fiber sensor according to claim 1, characterized in that: The distance between adjacent optical fiber gratings (31) is consistent with the distance between corresponding adjacent electric cores (11) in the first direction.

5. The battery pack with optical fiber sensor according to claim 1, characterized in that: In the battery module (10), the plurality of battery cells (11) are arranged in a rectangular array along the first direction and a second direction perpendicular to the first direction.

6. The battery pack with optical fiber sensor according to claim 1, characterized in that: The multiple battery cells (11) in the battery module (10) are square battery cells of the same model.

7. The battery pack with optical fiber sensor according to claim 1, characterized in that: The battery module (10) further comprises two end plates (13) and at least one tie band (14). The two end plates (13) are arranged opposite to each other and clamp the plurality of battery cells (11) therebetween; the two end plates (13) and the plurality of battery cells (11) are bound and fixed by means of the strap (14).

8. The battery pack with optical fiber sensor according to claim 1, characterized in that: The battery box (20) comprises a bottom plate (21) and an upper cover. The bottom plate (21) is a liquid cooling plate, and a fixing groove for accommodating the battery module (10) is provided on the bottom plate (21). The upper cover and the bottom plate (21) are assembled to form a closed chamber for accommodating the battery module (10).

9. The battery pack with optical fiber sensor according to any one of claims 1 to 8, characterized in that: Also includes a front panel (40), The front panel (40) is mounted on the battery box (20), and a conversion connector (41) is provided on the front panel (40). The interior of the conversion joint (41) is connected to one end of the optical fiber sensor (30), and the exterior is used to connect to an optical fiber demodulation device (50).

10. The battery pack with optical fiber sensor according to claim 9, characterized in that: It also comprises an optical fiber demodulation device (50), wherein the optical fiber demodulation device (50) is connected to the conversion joint (41).

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