Battery pack and energy storage device
By integrating a varistor layer and a wire layer into the sampling board with an integrated structure in the battery pack, the expansion force can be detected directly on the side of the cell, solving the problems of complex assembly and low reliability in the existing technology, and achieving the effects of simplified assembly and improved SOC monitoring accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUAWEI TECH CO LTD
- Filing Date
- 2025-04-08
- Publication Date
- 2026-06-23
Smart Images
Figure CN224400409U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy storage technology, and in particular to a battery pack and energy storage device. Background Technology
[0002] In related technologies, battery packs typically use pressure sensors to detect the expansion force of the battery cells. These pressure sensors employ independent sampling harnesses and signal processing modules, leading to complex and cumbersome battery pack assembly processes and resulting in low overall reliability. To increase system integration, some technologies connect the signal processing module and pressure sensor to a sampling board, for example, by plugging the pressure sensor onto the sampling board. However, plugging methods have low reliability, and the gold fingers of the signal interface are easily worn during the plugging process. Utility Model Content
[0003] The embodiments of this application provide a battery pack and energy storage device to solve the problem of complex battery pack assembly processes.
[0004] In a first aspect, embodiments of this application provide a battery pack, which includes a housing and multiple battery cells and a sampling plate housed within the housing. The multiple battery cells are arranged along the length of the battery pack. The sampling plate is an integral structure and includes a conductor layer and a varistor layer. The varistor layer is located on the side of one of the multiple battery cells along its length, and the conductor layer is located on the upper surface of the multiple battery cells and the side of one battery cell along its length. The varistor layer is attached to the conductor layer. In this embodiment, the sampling plate is an integral structure, and the varistor layer attached to the conductor layer provides pressure detection functionality. By attaching the varistor layer and conductor layer to the side of the battery cell along its length, the varistor layer and conductor layer are compressed when the battery cell expands. The varistor layer deforms under compression, causing a change in resistance. The pressure generated by the expansion of the battery cell, i.e., the expansion force of the battery cell, can be obtained from the change in resistance of the varistor layer. The expansion force of the battery cell can supplement the monitoring of the State of Charge (SOC) of the battery pack. The expansion force of the battery cell, together with current and voltage, can effectively improve the monitoring accuracy when calculating the SOC of the battery pack. Furthermore, because the sampling board has a one-piece structure, meaning the pressure detection function is integrated within the sampling board, it eliminates the need for a separate pressure sensor harness and external signal processing module, reducing the number of components. This effectively avoids complex wiring connections during assembly, improving reliability and reducing assembly steps and costs. It also avoids issues like poor contact and gold finger oxidation / wear caused by plugging and unplugging. In addition, the one-piece sampling board design allows for high-density circuit layout and thin-film encapsulation technology, maintaining the sampling board's slim profile while integrating pressure detection functionality, ensuring its flexibility within the battery pack remains unaffected.
[0005] In some embodiments, the varistor layer is located at one end of the sampling plate along its extension direction. Since the varistor layer is located at one end of the sampling plate, and the sampling plate is a one-piece structure, when assembling the sampling plate, one end plate of the sampling plate can be bent and placed on the side of a cell along its length, thus completing the assembly. This avoids complicating the entire assembly of the sampling plate by integrating a pressure detection function into the sampling plate.
[0006] In some embodiments, the other end of the sampling plate extending in the direction of extension is used to connect to the battery management unit (BMU). The conductor layer and the BMU are electrically connected to transmit the signal detected by the sampling plate to the BMU. In this embodiment, the sampling plate is connected to the BMU via the conductor layer, which can transmit the signal detected by the sampling plate to the BMU, such as the signal of the cell's expansion force detected by the sampling plate. The BMU then processes the signal. Since the pressure signal from the sampling plate does not require an additional signal processing module, but is directly processed by the BMU of the battery pack, it not only reduces costs but also effectively reduces the complexity of the entire battery pack system. Moreover, it is precisely because of the integrated structure of the sampling plate that the conductor layer and the varistor layer of the sampling plate itself jointly realize the pressure detection function, thus enabling the transmission of the detected pressure signal to the BMU through the conductor layer.
[0007] In some embodiments, the varistor layer is disposed on the side of the outermost cell in the length direction among multiple cells. Since the varistor layer is located on the side of the outermost cell among multiple cells, the sampling plate can extend to both sides of the multiple cells in the length direction, thereby allowing the sampling plate to reasonably collect information such as temperature, current or voltage of any cell among the multiple cells.
[0008] In some embodiments, the varistor layer is located in the middle portion of the sampling plate's extension direction. By placing the varistor layer in the middle portion of the sampling plate, it is possible to place the varistor layer on the side of the middle portion of a cell among multiple cells, thereby increasing the flexibility of the pressure sampling location.
[0009] In some embodiments, one end of the sampling plate is used to connect to the battery management unit, and the varistor layer is disposed on the side of the battery cell that is closest to the battery management unit in the longitudinal direction among the multiple battery cells. Because the varistor layer is disposed on the side of the battery cell that is closest to the battery management unit in the longitudinal direction among the multiple battery cells, the wire length of the conductor layer connecting the pressure detection point of the sampling plate and the battery management unit can be shortened, thereby reducing the transmission distance of the pressure signal and reducing the time delay of the pressure signal.
[0010] In some embodiments, the battery pack further includes fixing plates located on both sides of the multiple battery cells along its length. The fixing plates are used to fix the multiple battery cells. A varistor layer is located between the outermost side of the outermost battery cell and the inner side of the fixing plate along its length. The outermost side of the outermost battery cell is the surface facing the fixing plate, and the inner side of the fixing plate is the surface facing the battery cell. The battery management unit is located on the side of the fixing plate away from the multiple battery cells. One end of a sampling plate passes around the fixing plate from its bottom surface and connects to the battery management unit. In this embodiment, during assembly, the sampling plate passes around the fixing plate from its bottom surface and connects to the battery management unit via one end plate. This allows for proper assembly into the battery pack when the varistor layer is located in the middle of the sampling plate, simultaneously achieving connection with the battery management unit and its location on the side along the length of the battery cells. Furthermore, in this embodiment, the multiple battery cells, the fixing plates on both sides, and the sampling plate can be assembled first to form a battery module, and then the battery module can be placed inside the housing to form the battery pack, thus reducing assembly difficulty.
[0011] In some embodiments, the sampling plate includes a portion located on the upper surface of multiple battery cells and a portion located on the side of one battery cell along its length. A varistor layer is located on the side of one battery cell along its length. The portion of the sampling plate on the upper surface of the multiple battery cells is positioned between the positive and negative terminals of the battery cells along the width of the battery pack. This facilitates the assembly of the portion of the sampling plate on the upper surface of the battery cells, avoiding interference from the positive and negative terminals. The width dimension of the portion of the sampling plate located on the side of one battery cell along its length is larger than the width dimension of the portion of the sampling plate on the upper surface of the multiple battery cells. Because the portion of the sampling plate located on the side of the battery cell is larger, and there are no components on the side of the battery cell that interfere with the sampling plate, the portion of the sampling plate located on the side of the battery cell can also be made larger, for example, covering most of the area of the side of the battery cell, to increase the pressure monitoring area and improve the accuracy of pressure monitoring for battery cell expansion.
[0012] In some embodiments, the portion of the sampling plate located on the upper surface of multiple battery cells and the portion located on the side of a battery cell in the longitudinal direction have the same width in the width direction of the battery pack. The varistor layer is located on the side of a battery cell in the longitudinal direction, and the portion of the sampling plate located on the upper surface of multiple battery cells extends to both ends of the multiple battery cells in the width direction. Because the portion of the sampling plate located on the upper surface of multiple battery cells extends to both ends of the multiple battery cells in the width direction, that is, the sampling plate is designed to be wide enough, so that more temperature, current, voltage, and pressure detection points can be arranged to improve the monitoring accuracy of the sampling plate for the temperature, current, voltage, and pressure of the battery cells.
[0013] In some embodiments, the portion of the sampling plate located on the upper surface of multiple battery cells and the portion located on the side of a battery cell along its length have the same width in the width direction of the battery pack. The varistor layer is located on the side of a battery cell along its length, and the portion of the sampling plate located on the upper surface of multiple battery cells is positioned between the positive and negative terminals of the battery cell in the width direction. In this embodiment, because the portion of the sampling plate located on the upper surface of multiple battery cells is positioned between the positive and negative terminals of the battery cell in the width direction, and the width of the sampling plate is consistent at all positions, the processing difficulty of the sampling plate can be simplified, and the production cost of the sampling plate can be reduced.
[0014] In some embodiments, the conductor layer forms multiple electrodes on the side of a battery cell along its length. Each electrode is covered with a varistor layer. The multiple electrodes are arranged in multiple rows along the height direction, and the multiple rows of electrodes are spaced apart along the width direction of the battery pack. By using multiple electrodes and varistor layers to form multiple pressure detection points, pressure detection can be achieved at multiple points on the side of the battery cell, thereby improving the accuracy of monitoring the expansion force of the battery cell.
[0015] In some embodiments, the sampling plate further includes multiple temperature sampling units arranged in multiple columns along the height direction, and the columns of temperature sampling units spaced apart along the width direction of the battery pack. The multiple temperature sampling units are located at the gaps between multiple electrode spacings. Like multiple pressure detection points, the multiple temperature sampling units are located on the side of the sampled battery cell to fully utilize the wider width of the portion of the sampling plate where the pressure detection points are located, enabling temperature monitoring of most areas of the sampled battery cell's side through multiple temperature sampling units. By placing the multiple temperature sampling units at the gaps between the multiple pressure detection points, interference and influence on the pressure detection points can be avoided, while simultaneously enabling uniform temperature detection at various locations on the side of the sampled battery cell, avoiding the risk of missing detection at any particular location.
[0016] In some embodiments, the varistor layer is located along the length of the battery cells between the sides of two adjacent cells. This allows the varistor layer to be positioned in the middle of the battery cells along the length, rather than on the outermost edge. When located in the middle, the expansion force of the battery cells is not too far from the center position regardless of which end of the cell expands, thus improving the detection accuracy of the cell's expansion force.
[0017] In some embodiments, the sampling board includes a continuous first segment, a second segment, and a third segment. The first segment is located on the upper surface of a portion of the multiple battery cells, the second segment is located on the side of one battery cell along its length, and the third segment is located on the bottom surface of another portion of the multiple battery cells. The varistor layer is located in the second segment. In this embodiment, since the third segment is located on the bottom surface of another portion of the multiple battery cells, a portion of the sampling board needs to bypass the bottom surface of the battery cells to achieve the assembly of the sampling board, and the second segment containing the varistor layer can be located on the side of the battery cell. This also increases the flexibility of the sampling board assembly.
[0018] Secondly, embodiments of this application provide an energy storage device, which includes a cabinet and a battery pack as described in any of the first aspects above, with the battery pack housed within the cabinet. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.
[0020] Figure 1 This is a schematic diagram of a battery pack that can be used in energy storage devices.
[0021] Figure 2 for Figure 1 A partial structural diagram of the battery pack hidden behind the housing in the embodiment;
[0022] Figure 3 for Figure 2 An exploded view of the sampling plate in the embodiment;
[0023] Figure 4 This embodiment is a partial structural schematic diagram of another battery pack provided in the embodiments of this application;
[0024] Figure 5 This embodiment is a partial structural schematic diagram of another battery pack provided in the embodiments of this application;
[0025] Figure 6 This embodiment is a partial structural schematic diagram of another battery pack provided in the embodiments of this application;
[0026] Figure 7 This embodiment is a partial structural schematic diagram of another battery pack provided in the embodiments of this application;
[0027] Figure 8 The embodiment is a partial structural schematic diagram of another battery pack provided in the embodiments of this application.
[0028] Explanation of reference numerals in the attached figures:
[0029] 100. Battery pack;
[0030] 10. Shell; 11. End plate; 12. Side plate; 13. Bottom plate; 14. Top cover;
[0031] 20. Battery cell; 21. Top surface of battery cell; 22. Positive terminal; 23. Negative terminal; 24. Side of battery cell; 25. Bottom surface of battery cell;
[0032] 30. Sampling plate; 301. Temperature detection point; 302. Current detection point; 303. Voltage detection point; 304. Pressure detection point; 305. Through hole; 31. Substrate layer; 32. Conductor layer; 321. Electrode; 33. Varistor layer; 34. Cover layer; 35. First section; 36. Second section; 37. Third section; 38. Temperature sampling unit;
[0033] 40. Battery Management Unit;
[0034] 50. Fixing plate; 51. First fixing plate. Detailed Implementation
[0035] The following section will first explain some of the terms used in the embodiments of this application.
[0036] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0037] In this specification, the terms "vertical" and "parallel" are explained.
[0038] Perpendicularity: The perpendicularity defined in this application is not limited to an absolute perpendicular intersection (with an included angle of 90 degrees). It is permissible for non-absolute perpendicular intersections caused by factors such as assembly tolerances, design tolerances, and structural flatness. It is permissible for errors within a small angular range, such as an assembly error range of 80 to 100 degrees, which can all be understood as a perpendicular relationship.
[0039] Parallelism: The parallelism defined in this application is not limited to absolute parallelism. This definition of parallelism can be understood as basic parallelism, allowing for situations where the parallelism is not absolute due to factors such as assembly tolerances, design tolerances, and structural flatness. These situations may lead to the sliding mating part and the first door panel not being absolutely parallel, but this application also defines such situations as parallelism.
[0040] Modern society is filled with a vast number of devices that rely on electricity, from small household appliances to large data centers and factory production lines. Electricity supply is one of the factors that maintain the normal operation of modern society. Therefore, energy storage devices have developed rapidly and are widely used. This application provides an energy storage device, which can be a battery pack, an energy storage cabinet using a battery pack, a power cabinet for a data center, or even a vehicle using a battery pack. The energy storage device can be used to store electrical energy and to supply power to devices that require electricity. The energy storage device can be applied in fields such as site energy, photovoltaics, residential energy storage, industrial and commercial energy storage, and large-scale ground-mounted power plant energy storage.
[0041] An energy storage cabinet consists of a cabinet and a battery pack housed within it. The battery pack is used to store or discharge electricity. The battery pack can be a lithium-ion battery pack, such as a lithium iron phosphate battery pack, or a sodium-ion battery pack, etc.
[0042] Lithium-ion batteries are widely used in energy storage devices due to their reasonable price and mature technology. Some energy storage devices utilize lithium batteries for energy storage or discharge. However, lithium-ion batteries exhibit a relatively long charge / discharge plateau during charging and discharging. The SOC-OCV (State of Charge-Voltage) curve of the battery cell during charging and discharging is flat with a shallow slope, especially in the 20%-90% charge / discharge range. This flatness leads to significant errors in the accuracy of the Battery Management System (BMS) when monitoring the battery pack's SOC based on the lithium-ion battery voltage. Inaccurate SOC measurement can cause overcharging and over-discharging, resulting in battery pack damage. Furthermore, inaccurate SOC measurement reduces the system performance and reliability of the energy storage system using this battery pack, and can also cause errors in the estimated driving range of vehicles using this battery pack, resulting in low battery energy utilization efficiency. Therefore, inaccurate SOC measurement of the battery pack severely impacts the user experience.
[0043] To accurately measure the State of Charge (SOC) of the battery pack in the energy storage device of this embodiment, the battery pack in this embodiment collects more information, such as pressure in addition to current and voltage, to improve the accuracy of the SOC measurement. Figure 1 The battery pack in the embodiment.
[0044] Figure 1 This is a schematic diagram of a battery pack 100 that can be used in energy storage devices; Figure 2 for Figure 1 A partial structural diagram of the battery pack 100 hidden behind the housing 10 in the embodiment.
[0045] Reference Figure 1 and Figure 2 In this embodiment, the battery pack 100 includes a housing 10 and a plurality of battery cells 20 and a sampling plate 30 housed within the housing 10.
[0046] Reference Figure 1 In this embodiment, the housing 10 includes two end plates 11 opposite each other in the length direction of the battery pack 100, two side plates 12 opposite each other in the width direction of the battery pack 100, and a bottom plate 13 and a top cover 14 opposite each other in the height direction of the battery pack 100. For ease of description, the length direction of the battery pack 100 is referred to as X direction, the width direction of the battery pack 100 is referred to as Y direction, and the height direction of the battery pack 100 is referred to as Z direction.
[0047] Reference Figure 2 In this embodiment, multiple battery cells 20 are arranged along the X direction, meaning the thickness direction of all multiple battery cells 20 is aligned with the X direction. The positive and negative terminals 22 and 23 of the multiple battery cells 20 are located on the upper surface of the multiple battery cells 20 facing the top cover 14. It can be understood that because the multiple battery cells 20 are arranged along the X direction, the positive and negative terminals 22 and 23 of the multiple battery cells 20 are also arranged in an orderly manner along the X direction, so as to reserve space for the sampling board 30 for assembly.
[0048] Reference Figure 2 In this embodiment, the sampling board 30 is used to collect data such as voltage, temperature, current, and pressure of the battery pack 100, and transmits the collected data to the battery management unit 40 (BMU). The battery management unit 40 processes the collected data. For example, it calculates the SOC and SOH (State of Health) of the battery pack 100 based on the collected voltage and pressure information. In addition, the battery control unit can also control the charging and discharging power and monitor individual cell overcharging or over-discharging.
[0049] Specifically, refer to Figure 2 The sampling plate 30 includes a temperature detection point 301, a current detection point 302, a voltage detection point 303, and a pressure detection point 304. The temperature detection point 301 is connected to the battery cell 20 and is used to detect the temperature of the battery cell 20. The current detection point 302 is connected to the battery cell 20 and is used to detect the current of the battery cell 20. The voltage detection point 303 is connected to the battery cell 20 and is used to detect the voltage of the battery cell 20. The pressure detection point is attached to the battery cell 20 and is used to detect the expansion force of the battery cell 20.
[0050] The sampling board 30 can be a flexible printed circuit board (FPC). Due to its flexibility, the sampling board 30 can adapt to the complex spatial layout inside the battery pack 100, reduce the space occupied by traditional wiring harnesses, and improve integration.
[0051] Figure 2 In the battery pack 100 of the embodiment, since the sampling plate 30 can simultaneously collect voltage, temperature, current and pressure, it is understood that during the charging and discharging process of the battery pack 100, the cell 20 will expand. By detecting the pressure of the cell 20 on the sampling plate 30 when expansion occurs, the degree of expansion of the cell 20 can be determined. Taking the lithium iron phosphate battery pack 100 as an example, the pressure of the battery pack 100 during charging shows a characteristic trend of first rising, then falling and then rising again. This trend is related to the intrinsic characteristics of the battery pack 100. The inflection point of the pressure curve usually corresponds to a fixed capacity. This inflection point information can be used to calibrate the SOC of the battery pack 100. The inflection point of the pressure curve happens to correspond to the flat area of the SOC-OCV curve, which can make up for the defect that voltage cannot accurately monitor the SOC of the battery pack 100 in the flat area of the SOC-OCV curve. Thus, through the cooperation of voltage and pressure, pressure and voltage have complementary effects. When calculating the SOC of the battery pack 100, the SOC of the battery pack 100 can be monitored more accurately.
[0052] Reference Figure 2 Example: Battery pack 100 (e.g.) Figure 1 The battery pack 100 also includes two fixing plates 50 located on both sides of the plurality of battery cells 20 in the X direction. The two fixing plates 50 are used to press and fix the plurality of battery cells 20. It is understood that in some other embodiments, the plurality of battery cells 20 can also be fixed in the X direction by the end plate 11 of the housing 10, thereby eliminating the need for the two fixing plates 50 and reducing the cost of the battery pack 100.
[0053] The sampling board in the related technology does not have the function of pressure detection. The pressure sensor used to detect pressure is usually independent of the sampling board and uses a separate sampling harness and a separate signal processing module, which makes the battery pack assembly process complex and cumbersome, resulting in low overall reliability.
[0054] In other related technologies, to increase system integration, signal processing modules and pressure sensors are connected to a sampling board, for example, by plugging the pressure sensor onto the sampling board. However, plugging has low reliability, and the gold fingers of the signal interface are easily worn during the plugging process. Moreover, the assembly process using plugging is still relatively complex, and the soldering of the sampling board and signal processing module also presents reliability challenges. In addition, integrating the signal processing module onto the sampling board increases the board's thickness and reduces its flexibility.
[0055] Compared to related technologies, Figure 2 The sampling board 30 in the embodiment is an integrated structure that integrates the pressure detection function into the sampling board 30, thereby eliminating the need for a separate pressure sensor harness and external signal processing module, reducing the number of components, effectively avoiding complex harness connections during assembly, improving reliability, and reducing assembly steps and assembly costs.
[0056] Furthermore, by eliminating plug-in connections (such as gold finger mating) found in related technologies, issues such as poor contact and gold finger oxidation / wear caused by plugging and unplugging can be eliminated. The integrated design also reduces solder joints (such as the solder joints between the signal processing module and the sampling board 30), lowering the probability of cold solder joints and poor soldering. Moreover, even under vibration conditions in the battery pack 100, the integrated sampling board 30 poses no risk of loosening, especially for electric vehicles and other applications with high vibration risks. The integrated structure of the sampling board 30 avoids this risk. Additionally, through high-density circuit layout and thin-film encapsulation technology, the sampling board 30 maintains its thin and light characteristics while integrating pressure detection functionality, ensuring that its flexibility within the battery pack 100 remains unaffected.
[0057] It should be noted that the sampling board 30 in this embodiment is an integral structure, meaning that the sampling board 30 is an indivisible whole when it leaves the factory, or a whole that cannot be easily separated or reassembled, and all functional modules are integrated within the same frame.
[0058] Figure 3 for Figure 2 An exploded view of the sampling plate 30 in the embodiment. Figure 3 This is a top view of the sample plate 30 after it has been decomposed and flipped.
[0059] Reference Figure 3 In this embodiment, the sampling board 30 includes a substrate layer 31, a conductive layer 32, a varistor layer 33, and a cover layer 34. The substrate layer 31 and the cover layer 34 encapsulate the conductive layer 32 and the varistor layer 33. For example, the substrate layer 31, the conductive layer 32, the varistor layer 33, and the cover layer 34 are stacked sequentially so that the conductive layer 32 and the varistor layer 33 are encapsulated between the substrate layer 31 and the cover layer 34.
[0060] The substrate layer 31 can be made of polyimide, polyester, or other materials. The substrate layer 31 provides mechanical support and electrical insulation, serves as a carrier for the conductor layer 32, and determines the flexibility and temperature resistance of the sampling plate 30.
[0061] The conductor layer 32 can be made of metal such as copper foil, and can be etched to form circuit patterns to transmit electrical signals or power.
[0062] The material of the cover layer 34 can be polyimide, solder resist ink, etc. The cover layer 34 is used to protect the conductor layer 32 from oxidation, moisture and mechanical wear, and can also be used for insulation protection to prevent short circuits.
[0063] The piezoresistive layer 33 can be made of piezoresistive materials such as silicon or germanium. The piezoresistive layer 33 is used to convert mechanical pressure into electrical signals through piezoresistive, piezoelectric or capacitive effects, thereby realizing the sensing of pressure changes.
[0064] In addition, the sampling board 30 may also include an adhesive layer (not shown in the figure), such as bonding the substrate layer 31, the wire layer 32, the varistor layer 33, and the cover layer 34 through the adhesive layer. The adhesive layer may be made of acrylic glue or epoxy resin, etc. Furthermore, the sampling board 30 may also include a reinforcing layer (not shown in the figure), a shielding layer (not shown in the figure), and a surface treatment layer (not shown in the figure). The reinforcing layer can be used to locally increase rigidity, facilitating soldering or connector installation; the shielding layer can suppress electromagnetic interference or radio frequency interference; and the surface treatment layer can be used for oxidation resistance, improving the lifespan of the sampling board 30.
[0065] Figure 3 In this embodiment, the bonding of the piezoresistive layer 33 and the conductive layer 32 enables the sampling plate 30 to detect the magnitude of pressure. The piezoresistive layer 33 deforms when subjected to external pressure, and the magnitude of the external pressure can be obtained based on the magnitude of the deformation. The greater the deformation of the piezoresistive layer 33, the greater the external pressure.
[0066] Figure 3 In this embodiment, an electrode 321, such as an interdigitated electrode 321, can be formed through a portion of the conductive layer 32, and then a pressure-sensitive resistor layer 33 can be used to cover the electrode 321, thereby forming a pressure detection point 304 (e.g., Figure 2 An electrode 321, after covering the piezoresistive layer 33, forms a pressure detection point 304. Figure 3 The embodiment shows a pressure detection point 304. It is understood that in some other embodiments, the conductor layer 32 may have multiple electrodes 321, and after the multiple electrodes 321 are covered by the piezoresistive layer 33, multiple pressure detection points 304 are formed. The multiple pressure detection points 304 form a pressure detection point 304 array, and pressure information from more locations can be collected through multiple pressure detection points 304.
[0067] In order to pass Figure 2 and Figure 3 In this embodiment, the sampling plate 30 measures the expansion force of the battery cell 20, referring to... Figure 2 and Figure 3The sampling plate 30 extends to the side of one of the multiple battery cells 20 in the X direction. For ease of description, the battery cell 20 with the sampling plate 30 attached to its side in the X direction is designated as the sampling battery cell. The portion of the sampling plate 30 attached to the sampling battery cell has a conductive layer 32 and a varistor layer 33. That is, the varistor layer 33 is located on the side of the sampling battery cell in the X direction, and the conductive layer 32 is also located on the side of the sampling battery cell in the X direction. Moreover, the varistor layer 33 is attached to the conductive layer 32. Thus, the cooperation between the varistor layer 33 and the conductive layer 32 can play the role of pressure sensing and can be used to detect the applied pressure. Therefore, when the battery cell 20 expands, such as during charging, the varistor layer 33 attached to the side of the sampling cell in the X direction can sense the expansion of the battery cell 20. In conjunction with the wire layer 32, it can measure the pressure exerted by the expansion of the battery cell 20 on the varistor layer 33. This pressure is the expansion force of the battery cell 20. The detected expansion force of the battery cell 20 can be used to calibrate the battery pack 100 (e.g., ...). Figure 1 The sampling plate 30 can detect the state of charge (SOC) of the battery cell 20, thereby improving the accuracy of SOC monitoring. Furthermore, by detecting the expansion force of the battery cell 20, it can also determine whether the battery cell 20 is in a normal state, effectively reducing the probability of thermal runaway. It is understood that since multiple battery cells 20 are closely arranged along the X-direction, when any battery cell 20 expands, the expansion force can be transmitted to the sampling cell, and thus the expansion force of the battery cell 20 can be detected by the sampling plate 30.
[0068] In addition, a portion of the sampling plate 30 is located on the upper surface 21 of the multiple battery cells 20, that is, the multiple battery cells 20 face the top cover 14 (e.g., Figure 1 The surface of the sampling plate 30, i.e., the conductor layer 32, includes not only the portion located on the side of the sampling plate 30, but also the portion located on the upper surface 21 of the multiple battery cells 20. The portion of the sampling plate 30 located on the upper surface 21 of the multiple battery cells 20 can be used to detect the current, voltage, or temperature of the multiple battery cells 20. That is, the sampling plate 30 in this embodiment not only has the function of collecting current, voltage, and temperature as in existing sampling plates 30, but also has the function of collecting the expansion force of the battery cells 20, thereby improving the monitoring accuracy of the SOC and SOH of the battery pack 100 and improving the performance of the battery pack 100 (e.g., ...). Figure 1 (Safety of use)
[0069] It should be noted that, Figure 2 Although in this embodiment the sampling plate 30 is attached to the side 24 of only one of the multiple battery cells 20, in some other embodiments, the sampling plate 30 may be attached to the side 24 of at least two of the multiple battery cells 20 to detect the expansion force of the multiple battery cells 20, reduce monitoring errors, and improve the monitoring accuracy of the expansion force of the battery cells 20.
[0070] Reference Figure 2 and Figure 3 In this embodiment, the sampling board 30 is connected to the battery management unit 40, and the wiring layer 32 is electrically connected to the battery management unit 40, used to transmit the signals detected by the sampling board 30 to the battery management unit 40. Information such as temperature, current, voltage, and pressure collected by the sampling board 30 is transmitted to the battery management unit 40 through the wiring layer 32, where it is processed to obtain the battery pack 100 (e.g., ...). Figure 1 SOC and SOH.
[0071] Reference Figure 2 and Figure 3 In this embodiment, the pressure detection point 304 of the sampling plate 30 is located at one end of the extending direction of the sampling plate 30, that is, the varistor layer 33 is located at one end of the extending direction of the sampling plate 30, and the other end of the extending direction of the sampling plate 30 is used to connect to the battery management unit 40. Since the pressure detection point 304 is located at one end of the sampling plate 30, when assembling the sampling plate 30, it is only necessary to bend the part of the sampling plate 30 at one end from the upper surface 21 of the cell 20 toward the bottom surface 25 of the cell 20, and then attach it to the side of the sampling cell in the X direction. The majority of the sampling plate 30 between its two ends is located on the upper surface 21 of multiple cells 20, just like the FPC in the prior art. This layout of the sampling plate 30 does not increase the assembly complexity of the sampling plate 30.
[0072] Reference Figure 2 In this embodiment, the pressure detection point 304 of the sampling plate 30 is located on the side 24 of the outermost cell 20 in the X direction among the multiple cells 20, meaning the sampling cell is the outermost cell 20 among the multiple cells 20. In other words, the sampling plate 30 can extend from one side of the multiple cells 20 to the other along the X direction, facilitating connection with any of the multiple cells 20, thereby enabling the collection of current, voltage, or temperature information from any of the multiple cells 20. It is understood that in some other embodiments, the sampling plate 30 may also collect current, voltage, or temperature information from only a portion of the multiple cells 20.
[0073] Specifically, the portion of the sampling plate 30 with pressure detection points 304 is located between the side 24 of the outermost of the multiple battery cells 20 and the surface of the fixing plate 50 facing the battery cell 20. By placing the portion of the sampling plate 30 with pressure detection points 304 between the surface of the fixing plate 50 and the side 24 of the battery cell 20, the pressure detection points 304 of the sampling plate 30 can be squeezed when the battery cell 20 expands, that is, the pressure-sensitive resistor layer 33 of the pressure detection point 304 is squeezed (e.g., ...). Figure 3This allows us to obtain the magnitude of the pressure generated when the battery cell 20 expands, and thus the expansion force of the battery cell 20, which is then transmitted through the conductor layer 32 (e.g., ...). Figure 3 The signal is transmitted to the battery management unit 40 to calculate the battery pack 100 (e.g., ...). Figure 1 The system monitors the SOC and SOH of the battery pack 100 to prevent thermal runaway.
[0074] Reference Figure 2 In this embodiment, the width of the portion of the sampling plate 30 located on the upper surface 21 of the plurality of battery cells 20 in the Y direction is smaller than the distance between the positive terminal 22 and the negative terminal 23 of the battery cell 20 in the Y direction. That is, the portion of the sampling plate 30 located on the upper surface 21 of the plurality of battery cells 20 is positioned between the positive terminal 22 and the negative terminal 23 of the battery cell 20 in the Y direction, thereby avoiding the sampling plate 30 from affecting the normal installation of the busbar, etc.
[0075] Reference Figure 2 In this embodiment, the sampling plate 30 has a consistent width in the Y direction for the portion located on the upper surface 21 of the plurality of battery cells 20 and the portion located on the side of the sampling cell in the X direction. Therefore, when manufacturing the sampling plate 30, it is unnecessary to cut the substrate layer 31, the conductor layer 32, and the cover layer 34, reducing the processing difficulty of the sampling plate 30. Since the width of the sampling plate 30 in this embodiment is consistent at all locations and is smaller than the distance between the positive and negative terminals of the battery cell 20 in the Y direction, the width of the pressure detection point 304 in the Y direction should not be too large, and the number of pressure detection points 304 on the sampling plate 30 should not be excessive.
[0076] Figure 2 In this embodiment, the pressure detection point 304 is located at the end of the sampling plate 30. It is understood that in other embodiments, the pressure detection point 304 may also be located in the middle portion of the sampling plate 30, such as in the following examples. Figure 4 Example.
[0077] Figure 4 This embodiment is a partial structural schematic diagram of another battery pack 100 provided in the embodiments of this application. Figure 4 Same as the example Figure 2 The main difference between the embodiments lies in the structure of the sampling plate 30, which will be discussed in detail below. Figure 4 Examples and Figure 2 Differences in the embodiments, Figure 4 Examples and Figure 2 The same parts in the embodiments can be referred to. Figure 2 and Figure 3 Examples will not be repeated hereafter. For example... Figure 4 The conductive layer 32, varistor layer 33, electrode 321, etc. mentioned in the embodiment can all be referred to as Figure 3 Examples are not described in detail here.
[0078] Reference Figure 4 In this embodiment, the battery management unit 40 is located on the side of the fixing plate 50 away from the battery cell 20. The fixing plate 50 closer to the battery management unit 40 is designated as the first fixing plate 51. The pressure detection point 304 of the sampling plate 30 is located between the side of the sampling battery cell and the inner side of the first fixing plate 51, i.e., the varistor layer 33 (e.g., ...). Figure 3 The sampling plate 30 is located between the side 24 of the outermost cell 20 in the longitudinal direction and the inner side of the first fixing plate 51. The portion of the sampling plate 30 located on the upper surface 21 of the multiple cells 20 is the same as... Figure 2 As in the embodiment, it extends from one side of the plurality of cells 20 to the other side. (Similar to...) Figure 2 The difference in the embodiments is that, Figure 4 In this embodiment, the pressure detection point 304 of the sampling plate 30 is located in the middle portion of the sampling plate 30. One end of the sampling plate 30, used for connection to the battery management unit 40, extends from the bottom surface of the first fixing plate 51, bypasses the first fixing plate 51, and connects to the battery management unit 40. That is... Figure 2 In this embodiment, the pressure detection point 304 of the sampling plate 30 is located on the side 24 of the cell 20 that is furthest from the battery management unit 40 in the X direction among the multiple cells 20. Figure 4 In the embodiment, the pressure detection point 304 of the sampling plate 30 is located on the side 24 of the cell 20 that is closest to the battery management unit 40 in the X direction among the multiple cells 20. This can shorten the wire length of the wire layer 32 connecting the pressure detection point 304 of the sampling plate 30 and the battery management unit 40, reduce the transmission distance of the pressure signal, and reduce the time delay of the pressure signal.
[0079] In addition, with Figure 2 The difference in the embodiments is that, Figure 4 In the embodiment, the width of the portion where the pressure detection point 304 of the sampling plate 30 is located is greater than Figure 2 The width of the portion where the pressure detection point 304 of the sampling plate 30 is located in the embodiment. Specifically, the conductive layer 32 forms a plurality of electrodes 321 (e.g., ...). Figure 3 For example, the interdigitated electrodes 321 are covered with a pressure-sensitive resistor layer 33. After multiple electrodes 321 are covered with a pressure-sensitive resistor layer 33, multiple pressure detection points 304 are formed. The multiple pressure detection points 304 are all located on the side of the sampling cell in the X direction, so that a larger area of the side of the sampling cell can be sampled for pressure, thereby improving the detection accuracy of the expansion force of the cell 20.
[0080] Reference Figure 4 In the embodiment, multiple electrodes 321 (such as...) Figure 3The multiple pressure detection points 304 of the sampling plate 30 are arranged in multiple rows along the height direction, and the multiple rows of electrodes 321 are arranged at intervals along the width direction of the battery pack 100. That is, the multiple pressure detection points 304 of the sampling plate 30 are arranged in multiple rows along the Z direction, and the multiple rows of pressure detection points 304 are arranged at intervals along the Y direction of the battery pack 100. This regular arrangement of the multiple pressure detection points 304 not only facilitates manufacturing but also allows for even distribution on the side of the sampling cell, reducing the risk of missed detection at a certain location. It is understood that in some other embodiments, the multiple pressure detection points 304 may be arranged in other ways or irregularly.
[0081] Figure 5 This embodiment is a partial structural schematic diagram of another battery pack 100 provided in the embodiments of this application. Figure 5 Same as the example Figure 2 The main difference between the embodiments lies in the structure of the sampling plate 30, which will be discussed in detail below. Figure 5 Examples and Figure 2 Differences in the embodiments, Figure 5 Examples and Figure 2 The same parts in the embodiments can be referred to. Figure 2 and Figure 3 Examples will not be repeated hereafter. For example... Figure 5 The conductive layer 32, varistor layer 33, electrode 321, etc. mentioned in the embodiment can all be referred to as Figure 3 Examples are not described in detail here.
[0082] and Figure 2 The same applies to the embodiments, Figure 5 In the embodiment, the pressure detection point 304 of the sampling plate 30 is also located at one end of the extending direction of the sampling plate 30, and the same Figure 2 The difference in the embodiments is that, Figure 5 The width of the portion of the sampling plate 30 in the embodiment where the pressure detection point 304 is located is greater than Figure 2 The width of the portion where the pressure detection point 304 of the sampling plate 30 is located in the embodiment. (Same) Figure 4 As in the embodiment, the conductor layer 32 forms a plurality of electrodes 321 (e.g. Figure 3 Multiple electrodes 321 are covered with a varistor layer 33 (e.g., Figure 3Multiple pressure detection points 304 are then formed, all located on the side of the sampling cell in the X direction. This allows for pressure sampling over a larger area of the side of the sampling cell, improving the accuracy of detecting the expansion force of the cell 20. Furthermore, the multiple pressure detection points 304 on the sampling plate 30 are arranged in multiple rows along the Z direction, and these rows are spaced apart along the Y direction of the battery pack 100. This regular arrangement of the pressure detection points 304 not only facilitates manufacturing but also ensures even distribution on the side of the sampling cell, reducing the risk of missed detections at certain locations.
[0083] Figure 6 This embodiment is a partial structural schematic diagram of another battery pack 100 provided in the embodiments of this application. Figure 6 Same as the example Figure 5 The main difference between the embodiments lies in the structure of the sampling plate 30, which will be discussed in detail below. Figure 6 Examples and Figure 5 Differences in the embodiments, Figure 6 Examples and Figure 5 The same parts in the embodiments can be referred to. Figure 2 and Figure 3 Examples will not be repeated hereafter.
[0084] Figure 6 Implementation examples in Figure 5 Based on the embodiment, the sampling plate 30 also includes multiple temperature sampling units 38. The multiple temperature sampling units 38, like the multiple pressure detection points 304, are all located on the side of the sampling cell. This makes full use of the advantage of the wider width of the part where the pressure detection points 304 of the sampling plate 30 are located, so that the temperature of most of the side 24 of the sampled cell 20 can be monitored by the multiple temperature sampling units 38.
[0085] Specifically, multiple temperature sampling units 38 are arranged in multiple rows along the height direction, and the multiple rows of temperature sampling units 38 are arranged at intervals along the width direction of the battery pack 100. The multiple temperature sampling units 38 are located at the gaps between the multiple pressure detection points 304. By placing the multiple temperature sampling units 38 at the gaps between the multiple pressure detection points 304, interference and influence on the pressure detection points 304 can be avoided. At the same time, the temperature of each position on the side of the sampled battery cell can be detected evenly, avoiding the risk of missing detection at a certain position.
[0086] Figure 7 This embodiment is a partial structural schematic diagram of another battery pack 100 provided in the embodiments of this application. Figure 7 Same as the example Figure 5 The main difference between the embodiments lies in the structure of the sampling plate 30, which will be discussed in detail below. Figure 7 Examples and Figure 5Differences in the embodiments, Figure 7 Examples and Figure 5 The same parts in the embodiments can be referred to. Figure 5 Examples will not be repeated hereafter.
[0087] and Figure 5 The difference in the embodiments is that, Figure 7 In this embodiment, the width of the portion of the sampling plate 30 located on the upper surface 21 of the multiple battery cells 20 is the same as the width of the portion located on the side of the sampling cell. Therefore, the width of the portion of the sampling plate 30 located on the upper surface 21 of the multiple battery cells 20 is greater than the distance between the positive terminal 22 and the negative terminal 23 of the battery cell 20. Specifically, through holes 305 are provided at positions corresponding to the positive terminal 22 and the negative terminal 23 of the multiple battery cells 20. The positive terminal 22 and the negative terminal 23 pass through the sampling plate 30 via the through holes 305 to facilitate connection with the electrode tabs. In this embodiment, there is no need to cut the sampling plate 30. The portion of the sampling plate 30 located on the upper surface 21 of the multiple battery cells 20 can cover most of the upper surface 21 of the multiple battery cells 20. This portion of the sampling plate 30 can have a greater number of detection points, such as more temperature detection points 301, current detection points 302, and voltage detection points 303, to monitor the battery pack 100 (e.g., ...). Figure 1 (to improve detection capabilities)
[0088] The varistor layer 33 of the sampling plate 30 in the previous embodiment (e.g.) Figure 3 The varistor layer 33 of the sampling plate 30 is located on the side 24 of the outermost cell 20 in the X direction. In some other embodiments, the varistor layer 33 of the sampling plate 30 may also be located between two adjacent cells 20 in the X direction, such as in the following... Figure 8 Example.
[0089] Figure 8 This embodiment is a partial structural schematic diagram of another battery pack 100 provided in the embodiments of this application. Figure 8 Same as the example Figure 2 The main difference between the embodiments lies in the structure of the sampling plate 30, which will be discussed in detail below. Figure 8 Examples and Figure 2 Differences in the embodiments, Figure 8 Examples and Figure 2 The same parts in the embodiments can be referred to. Figure 2 and Figure 3 Examples will not be repeated hereafter.
[0090] Reference Figure 8 In this embodiment, the portion of the sampling plate 30 where the pressure detection point 304 is located is between the sides 24 of two adjacent cells 20 in the X direction, i.e., the varistor layer 33 (e.g. Figure 3 In the X direction, it is located between the sides 24 of two adjacent cells 20 among a plurality of cells 20.
[0091] Specifically, the sampling plate 30 includes a continuous first segment 35, a second segment 36, and a third segment 37. The first segment 35 is located on the upper surface 21 of a portion of the multiple battery cells 20 (e.g., ...). Figure 2 The second segment 36 is located on the side of a cell 20 along its length, and the third segment 37 is located on the bottom surface 25 of another portion of the cells 20. The varistor layer 33 (e.g.) Figure 3 Located in the second segment 36. In this embodiment, the sampling plate 30 needs to bypass part of the bottom surface 25 of the battery cell 20 during assembly. In this way, the varistor layer 33 can be placed in the middle part of the multiple battery cells 20 in the X direction, instead of the outermost part. When it is located in the middle, no matter which end of the battery cell 20 in the X direction expands, the distance from the middle position is not too far, thereby improving the detection accuracy of the expansion force of the battery cell 20.
[0092] Furthermore, this method allows for pressure detection of multiple battery cells 20 using an integrated sampling plate 30. For example, in some embodiments, one end of the sampling plate 30 is connected to the battery management unit 40. The sampling plate 30 sequentially passes over the upper surface 21 of some of the battery cells 20, between two adjacent battery cells 20, the bottom surface 25 of another portion of the battery cells 20, the side surface 24 of the outermost battery cell 20 furthest from the battery management unit 40 in the length direction, and the upper surface 21 of another portion of the battery cells 20. The portion of the sampling plate 30 located between two adjacent battery cells 20 has a pressure detection point 304. In this embodiment, the pressure detection point 304 can be located either on the side surface 24 of the outermost battery cell 20 or between the side surfaces 24 of two adjacent battery cells 20, thereby enabling detection of multiple battery cells 20 and improving detection accuracy.
[0093] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A battery pack, characterized in that, The battery pack includes a housing and multiple battery cells and a sampling plate housed within the housing, wherein the multiple battery cells are arranged along the length of the battery pack. The sampling board is an integral structure and includes a conductor layer and a varistor layer. The varistor layer is located on the side of one of the multiple battery cells in the length direction. The conductor layer is located on the upper surface of the multiple battery cells and the side of the one battery cell in the length direction. The varistor layer is attached to the conductor layer.
2. The battery pack according to claim 1, characterized in that, The varistor layer is located at one end of the sampling plate in the extension direction.
3. The battery pack according to claim 1 or 2, characterized in that, The other end of the sampling plate is used to connect to the battery management unit. The wire layer and the battery management unit are electrically connected to transmit the signal detected by the sampling plate to the battery management unit.
4. The battery pack according to any one of claims 1-3, characterized in that, The varistor layer is disposed on the side of the outermost cell in the length direction among the plurality of cells.
5. The battery pack according to claim 1, characterized in that, The varistor layer is located in the middle part of the extension direction of the sampling plate.
6. The battery pack according to claim 5, characterized in that, One end of the sampling plate is used to connect to the battery management unit, and the varistor layer is disposed on the side of the battery cell that is closest to the battery management unit in the length direction among the plurality of battery cells.
7. The battery pack according to claim 5 or 6, characterized in that, The battery pack further includes fixing plates located on both sides of the plurality of battery cells along the length direction. The fixing plates are used to fix the plurality of battery cells. The varistor layer is located between the outer surface of the outermost battery cell along the length direction and the inner surface of the fixing plate. The outer surface of the outermost battery cell is the surface of the battery cell facing the fixing plate, and the inner surface of the fixing plate is the surface of the fixing plate facing the battery cell. The battery management unit is located on the side of the fixing plate away from the plurality of battery cells. One end of the sampling plate passes around the fixing plate from the bottom surface of the fixing plate and is connected to the battery management unit.
8. The battery pack according to any one of claims 1-7, characterized in that, The sampling plate includes a portion located on the upper surface of the plurality of cells and a portion located on the side of the one cell in the length direction. The varistor layer is located on the side of the one cell in the length direction. The portion of the sampling plate located on the upper surface of the plurality of cells is located between the positive and negative terminals of the cell in the width direction of the battery pack. The dimension of the portion of the sampling plate located on the side of the one cell in the length direction in the width direction is larger than the dimension of the portion of the sampling plate located on the upper surface of the plurality of cells in the width direction.
9. The battery pack according to any one of claims 1-7, characterized in that, The sampling plate has the same width in the width direction as the portion of the sampling plate located on the upper surface of the plurality of cells and the portion located on the side of the cell in the length direction. The varistor layer is located on the side of the cell in the length direction, and the portion of the sampling plate located on the upper surface of the plurality of cells extends to both ends of the plurality of cells in the width direction.
10. The battery pack according to any one of claims 1-7, characterized in that, The sampling plate has the same width in the width direction as the portion of the sampling plate located on the upper surface of the plurality of cells and the portion located on the side of the cell in the length direction. The varistor layer is located on the side of the cell in the length direction, and the portion of the sampling plate located on the upper surface of the plurality of cells is located between the positive and negative terminals of the cell in the width direction.
11. The battery pack according to any one of claims 1-10, characterized in that, The conductor layer forms multiple electrodes on the side of the cell along its length, and each electrode is covered with the varistor layer. The multiple electrodes are arranged in multiple columns along the height of the battery pack, and the multiple columns of electrodes are spaced apart along the width of the battery pack.
12. The battery pack according to claim 11, characterized in that, The sampling plate also includes multiple temperature sampling units, which are arranged in multiple columns along the height direction. The multiple columns of temperature sampling units are spaced apart along the width direction of the battery pack. The multiple temperature sampling units are located at the gaps between the multiple electrode spacings.
13. The battery pack according to claim 1, characterized in that, The varistor layer is located along the length direction between the sides of two adjacent cells among the plurality of cells.
14. The battery pack according to claim 13, characterized in that, The sampling plate includes a first segment, a second segment, and a third segment. The first segment is located on the upper surface of a portion of the plurality of battery cells. The second segment is located on the side of a battery cell in the length direction. The third segment is located on the bottom surface of another portion of the plurality of battery cells. The varistor layer is located in the second segment.
15. An energy storage device, characterized in that, The energy storage device includes a cabinet and a battery pack as described in any one of claims 1-14, wherein the battery pack is disposed within the cabinet.