WO2023207819A1 - 电池模组、电池包和用电装置 - Google Patents

电池模组、电池包和用电装置 Download PDF

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Publication number
WO2023207819A1
WO2023207819A1 PCT/CN2023/089982 CN2023089982W WO2023207819A1 WO 2023207819 A1 WO2023207819 A1 WO 2023207819A1 CN 2023089982 W CN2023089982 W CN 2023089982W WO 2023207819 A1 WO2023207819 A1 WO 2023207819A1
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WO
WIPO (PCT)
Prior art keywords
battery
expansion
strain gauge
layer
deformation
Prior art date
Application number
PCT/CN2023/089982
Other languages
English (en)
French (fr)
Inventor
李文博
李乔峰
王芳婷
赵越
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
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Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Publication of WO2023207819A1 publication Critical patent/WO2023207819A1/zh

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
    • H01M10/482—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte for several batteries or cells simultaneously or sequentially
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/425—Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/249—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders specially adapted for aircraft or vehicles, e.g. cars or trains
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/425—Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing
    • H01M2010/4271—Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • Embodiments of the present application relate to the field of batteries, and more specifically, to battery modules, battery packs and electrical devices.
  • Information such as battery current, voltage and temperature can reflect whether the battery has failed.
  • information such as battery current, voltage, and temperature.
  • the battery When the current, voltage, temperature and other information of the battery are abnormal, the battery has often failed. At this time, the battery may have caused relatively serious safety hazards, such as burning, explosion, etc. Therefore, based only on the battery's current, voltage, temperature and other information, it is impossible to warn of battery failure in advance, to adjust the battery charging and discharging status in advance, and to prevent battery safety accidents in time.
  • battery expansion information can be used to predict whether the battery is about to fail.
  • the battery may also swell.
  • the battery expansion situation can be relatively complicated. For example, the battery can expand locally or as a whole. How to accurately detect battery expansion information to predict whether the battery is about to fail is a technical problem that needs to be solved.
  • Embodiments of the present application provide a battery module, a battery pack and an electrical device, with the purpose of relatively accurately detecting battery expansion information, so as to relatively accurately predict whether the battery is about to fail.
  • a battery module including:
  • the expansion detection assembly includes:
  • the deformation layer includes a first end surface and a second end surface, the first end surface is disposed close to the battery, the second end surface is disposed away from the battery, the second end surface of the deformation layer is provided with a groove ;
  • a strain gauge is provided on the deformation layer, and the strain gauge is used to detect the strain of the groove bottom surface of the groove.
  • the expansion detection component deforms under the action of the battery expansion force.
  • the strain gauge can detect the deformation of the expansion detection component and thereby obtain the battery expansion force endured by the expansion detection component. Therefore, the expansion information of the battery module can be detected, which is helpful for accurately assessing the status of the battery module and predicting battery module failure.
  • the specific form of battery expansion can be different.
  • the center of expansion of a battery is at the center or center of gravity of the battery.
  • the expansion center of the battery deviates from the center or center of gravity of the battery.
  • the expansion detection component can deform in response to the battery expansion force, so that in scenarios with complex and diverse expansion amounts, the expansion detection component can take into account a variety of battery expansion situations. In other words, the detection of battery expansion force is not limited to the specific battery expansion amount.
  • the expansion detection component further includes a pressure-bearing layer and a stress concentration layer, and the stress concentration layer is located between the pressure-bearing layer and the deformation layer, The pressure-bearing layer is adjacent to the battery, and the bottom surface of the groove can be deformed under the action of the stress concentration layer.
  • the stress concentration layer can apply relatively large pressure to the deformation layer, making the deformation amount of the deformation layer relatively obvious.
  • the deformation amount of the deformation layer can be distinguished relatively clearly, which is beneficial to improving the detection accuracy of the battery expansion information.
  • the strain gauge is disposed on the bottom surface of the groove and is located outside the area of the bottom surface of the groove opposite to the stress concentration layer.
  • the separation distance between the deformation layer and the stress concentration layer may be relatively narrow.
  • the shape of the groove bottom surface is a rectangle, the groove bottom surface includes an edge sub-region, the edge sub-region is located between the groove wall and the groove wall of the groove. Between the areas of the groove bottom surface opposite to the stress concentration layer, the edge sub-region is arranged parallel to the long side or short side of the groove bottom surface;
  • the strain gauge is disposed at the center of the edge sub-region, or the strain gauge is disposed at an end of the edge sub-region.
  • the strain gauge When the strain gauge is placed in the center of the edge sub-area, the strain gauge can be mainly used to detect the strain on the symmetry axis or in a certain direction, thereby reflecting the component of the battery expansion force on the symmetry axis or in a certain direction. This is beneficial to obtain expansion information on the symmetry axis or in a certain direction.
  • the strain at the end of the edge sub-region can have components in multiple directions, which is beneficial to comprehensively reflect the total battery expansion force.
  • Strain gauges may also be provided between the center of the edge sub-region and the ends of the edge sub-region. There may be local special deformations at the ends of the edge subregions. There is a certain distance between the strain gauge and the end of the edge sub-region, which is beneficial to reducing the possibility of the strain gauge detecting local special deformation and reducing the impact of local special deformation on the overall expansion information.
  • the center position of the edge sub-region and the center position of the edge sub-region bear relatively small stress, the center position of the edge sub-region and the center position of the edge sub-region are more prone to elastic recovery. This is beneficial to realizing the expansion detection component to work in cycles multiple times.
  • the first end surface includes a deformation area opposite to the groove bottom surface, and the strain gauge is disposed in the deformation area and located on the deformation area. outside the area opposite to the stress concentration layer.
  • the strain gauge can be hidden in the gap between the deformation layer and the stress concentration layer, which helps reduce the possibility of the strain gauge falling off.
  • the strain gauge is disposed on an axis of symmetry of the edge portion, or the strain gauge is disposed on a corner of the edge portion.
  • the strain gauge When the strain gauge is placed on the symmetry axis of the edge part, the strain gauge can be mainly used to detect the strain in the direction of the symmetry axis, thereby reflecting the component of the battery expansion force in the direction of the symmetry axis, which is beneficial to obtaining the symmetry axis. Expansion information in the direction.
  • the strain at the corner of the edge portion can have components in multiple directions, which is beneficial to comprehensively reflect the total battery expansion force.
  • the stiffness of the pressure-bearing layer is greater than the stiffness of the bottom surface of the groove.
  • the stiffness of the pressure-bearing layer is relatively large, which is beneficial to reducing the deformation of the pressure-bearing layer, so that the battery expansion force can be reflected through the deformation of the groove bottom surface of the deformation layer as much as possible.
  • the stiffness of the stress concentration layer is greater than the stiffness of the bottom surface of the groove.
  • the stiffness of the stress concentration layer is relatively large, which is beneficial to reducing the deformation of the stress concentration layer, so that the battery expansion force can be reflected through the deformation of the groove bottom surface of the deformation layer as much as possible.
  • the pressure-bearing layer, the stress concentration layer and the deformation layer are integrally formed.
  • the first end surface is adjacent to the battery.
  • the deformation layer is in direct contact with the battery module, which is conducive to relatively dynamically obtaining the specific expansion amount of the battery.
  • the strain gauge is provided on the bottom surface of the groove; or, the first end surface includes a deformation area opposite to the bottom surface of the groove, and the Strain gauges are arranged in the deformation area.
  • the strain gauge can be hidden in the groove, which helps reduce the space occupied by the strain gauge in the battery module.
  • the strain gauge can be sandwiched between the deformation layer and the battery, which is beneficial to directly sensing the specific expansion amount of the battery.
  • the material of the deformation layer is any one of the following: alloy steel, aluminum alloy, and titanium alloy.
  • the stiffness of the deformation layer can be relatively high, which is conducive to the elastic deformation of the deformation layer under the action of the battery expansion force, reducing the possibility of yielding of the deformation layer, and thus is conducive to allowing the expansion detection component to work multiple times.
  • the shape of the groove bottom surface is any one of the following: rectangular, circular, and elliptical.
  • the deformation layer can capture relatively more battery expansion information.
  • the battery module further includes an end plate, and the expansion detection component is sandwiched between the end plate and the battery.
  • the expansion detection component is placed close to the end plate, which is conducive to capturing the expansion information of multiple batteries in the battery module.
  • a battery pack including the battery module as described in any implementation of the first aspect.
  • the battery pack further includes a battery management system BMS control module, and the BMS control module is used to obtain the signal output by the strain gauge.
  • the BMS control module can flexibly obtain battery expansion information and flexibly adjust the battery's working status so that the battery can be in a relatively healthy state.
  • the BMS control module can also predict whether the battery is about to fail based on the battery's expansion information, and take first aid measures before failure.
  • a battery pack including:
  • the expansion detection assembly includes:
  • the deformation layer includes a first end surface and a second end surface, the first end surface is arranged close to the battery, the second end surface is arranged away from the battery, the second end surface of the deformation layer is provided with a The grooves opposite to the battery;
  • a strain gauge is provided on the deformation layer, and the strain gauge is used to detect the strain of the groove bottom surface of the groove.
  • the battery pack further includes a battery management system BMS control module, and the BMS control module is used to obtain the signal output by the strain gauge.
  • an electrical device including the battery pack as described in any one of the above implementations of the second to third aspects.
  • the fifth aspect provides a method to obtain expansion information, including:
  • Expansion information is obtained according to the first signal and an expansion detection parameter, the expansion detection parameter is used to indicate the relationship between the first signal and the battery expansion force, and the expansion information is used to indicate the battery expansion force.
  • the electrical device described in any implementation manner of the fourth aspect can achieve a substantially linear relationship between the battery expansion force and the voltage difference of the strain gauge, so the battery expansion force can be estimated relatively accurately.
  • the expansion detection parameter includes at least one of the following:
  • the amount of strain detected by the strain gauge - the slope of the battery expansion force
  • strains detected by the strain gauge and multiple battery expansion forces are in one-to-one correspondence with the multiple battery expansion forces
  • the strain gauge coefficient of the strain gauge is the strain gauge coefficient of the strain gauge
  • the richer the expansion detection parameters the richer the battery expansion information obtained. For example, the battery expansion force, the location where the battery expansion force will act, etc. can be estimated, and the detection range can be adjusted.
  • the method further includes:
  • the acting position of the battery expansion force is determined.
  • the method further includes:
  • the expansion detection parameter is calibrated based on the force applied to the expansion detection component and the second signal.
  • the expansion detection component can be calibrated, which is beneficial to obtaining the battery expansion information relatively accurately in the future.
  • the method further includes:
  • an expansion detection component including:
  • the deformation layer includes a first end surface and a second end surface, the first end surface is used to be placed close to the battery, the second end surface is used to be placed away from the battery, the second end surface of the deformation layer is provided with a groove for opposing the battery;
  • a strain gauge is provided on the deformation layer, and the strain gauge is used to detect the strain of the groove bottom surface of the groove.
  • the expansion detection component further includes a pressure-bearing layer and a stress concentration layer, and the stress concentration layer is located between the pressure-bearing layer and the deformation layer,
  • the pressure-bearing layer is used to contact the battery
  • the first end surface includes a deformation area opposite to the bottom surface of the groove
  • the deformation area includes a middle part and an edge part
  • the middle part is in contact with the stress
  • the concentration layers are connected, and the edge portion surrounds the outer periphery of the stress concentration layer.
  • some or all of the strain gauges are disposed on the bottom surface of the groove and are located outside the area of the bottom surface of the groove opposite to the stress concentration layer.
  • the shape of the groove bottom surface is a rectangle, the groove bottom surface includes an edge sub-region, the edge sub-region is located between the groove wall and the groove wall of the groove. Between the areas of the groove bottom surface opposite to the stress concentration layer, the edge sub-region is arranged parallel to the long side or short side of the groove bottom surface;
  • the strain gauge is disposed at the center of the edge sub-region, or the strain gauge is disposed at an end of the edge sub-region.
  • some or all of the strain gauges are disposed on the edge portion.
  • the strain gauge is disposed on an axis of symmetry of the edge portion, or the strain gauge is disposed on a corner of the edge portion.
  • the stiffness of the pressure-bearing layer is greater than the stiffness of the bottom surface of the groove.
  • the stiffness of the stress concentration layer is greater than the stiffness of the bottom surface of the groove.
  • the pressure-bearing layer, the stress concentration layer and the The deformation layer is integrally formed.
  • the first end surface is used to contact the battery.
  • the strain gauge is provided on the bottom surface of the groove; or, the first end surface includes a deformation area opposite to the bottom surface of the groove, and the Strain gauges are arranged in the deformation area.
  • the material of the deformation layer is any one of the following: alloy steel, aluminum alloy, and titanium alloy.
  • the shape of the groove bottom surface is any one of the following: rectangular, circular, and elliptical.
  • Figure 1 is a schematic structural diagram of an electrical device provided by an embodiment of the present application.
  • Figure 2 is a schematic structural diagram of a battery pack provided by an embodiment of the present application.
  • FIG. 3A is a schematic structural diagram of a battery module provided by an embodiment of the present application.
  • Figure 3B is an exploded view of a battery module provided by an embodiment of the present application.
  • FIG. 4A is a schematic structural diagram of another battery module provided by an embodiment of the present application.
  • FIG. 4B is an exploded view of another battery module provided by an embodiment of the present application.
  • FIG. 5A is a schematic structural diagram of an expansion detection component provided by an embodiment of the present application.
  • Figure 5B is an exploded view of an expansion detection component provided by an embodiment of the present application.
  • FIG. 6A is a schematic structural diagram of a strain gauge provided by an embodiment of the present application.
  • FIG. 6B is a schematic structural diagram of another strain gauge provided by an embodiment of the present application.
  • Figure 6C is a schematic structural diagram of yet another strain gauge provided by an embodiment of the present application.
  • FIG. 7A is a schematic structural diagram of the expansion detection component shown in FIG. 5A in an initial state.
  • FIG. 7B is a schematic structural diagram of the expansion detection component shown in FIG. 5A in a detection state.
  • FIG. 8A is a schematic structural diagram of another expansion detection component provided by an embodiment of the present application.
  • Figure 8B is an exploded view of another expansion detection component provided by an embodiment of the present application.
  • Figure 9A is a schematic structural diagram of yet another expansion detection component provided by an embodiment of the present application.
  • Figure 9B is an exploded view of yet another expansion detection component provided by an embodiment of the present application.
  • FIGS. 10A to 10D are simulation result diagrams of the expansion detection component shown in FIG. 5A .
  • 11A to 11D show the arrangement position of the strain gauge on the expansion detection assembly.
  • Fig. 12 is a diagram of experimental results of the expansion detection assembly shown in Fig. 5A.
  • Figure 13 is a schematic structural diagram of an expansion detection component provided by an embodiment of the present application.
  • Figure 14 is a schematic flow chart for obtaining expansion information provided by an embodiment of the present application.
  • Figure 15 is a schematic diagram of obtaining the expansion action center provided by the embodiment of the present application.
  • Figures 16A and 16B are experimental result diagrams of an expansion detection component provided by embodiments of the present application.
  • FIG. 17A is a schematic structural diagram of a battery module provided by an embodiment of the present application.
  • Figure 17B is an exploded view of a battery module provided by an embodiment of the present application.
  • FIG. 18A is a schematic structural diagram of another battery module provided by an embodiment of the present application.
  • Figure 18B is an exploded view of another battery module provided by an embodiment of the present application.
  • Figure 19A is a schematic structural diagram of an expansion detection component provided by an embodiment of the present application.
  • Figure 19B is a schematic structural diagram of another expansion detection component provided by an embodiment of the present application.
  • Figure 19C is a schematic structural diagram of yet another expansion detection component provided by an embodiment of the present application.
  • Figures 20A to 20I show the placement positions of strain gauges on the expansion detection assembly.
  • FIG. 1 is a schematic structural diagram of an electrical device 100 provided by an embodiment of the present application.
  • the electrical device 100 may be, for example, a vehicle, a ship, or other mobile device.
  • vehicles can be electric vehicles/electric vehicles, such as pure electric vehicles, hybrid vehicles, extended range electric vehicles, fuel cell vehicles, plug-in hybrid vehicles, new energy vehicles (new energy vehicles), etc.
  • Electric vehicles can include two-wheeled, three-wheeled or four-wheeled electric vehicles.
  • the solution applied to the electrical device 100 in the embodiment of the present application can also be applied to other devices, such as terminal consumer products or 3C electronic products (computer, communication, consumer electronic products), Such as mobile phones, power banks, tablets, e-readers, laptops, digital cameras, wearable devices, headphones, etc.
  • the embodiment shown in FIG. 1 is explained by taking the electrical device 100 as a vehicle as an example.
  • the electric device 100 may include a front wheel 121, a rear wheel 122, and a vehicle body connected between the front wheel 121 and the rear wheel 122.
  • Several components may be installed on the vehicle body, and these components may drive the front wheels 121 and/or the rear wheels 122 to rotate, thereby moving the electrical device 100 .
  • transmission components, motors and battery packs 130 may be installed on the vehicle body.
  • the battery pack 130 can input electric energy to the motor, so that the motor can rotate and drive the front wheel 121 and/or the rear wheel 122 to rotate through the transmission component.
  • FIG. 2 is a schematic structural diagram of a battery pack 130 provided by an embodiment of the present application.
  • the battery pack 130 may include a battery box 131, and a plurality of battery modules 200 may be disposed in the battery box 131.
  • the battery box 131 may include a battery box body and a cover.
  • the cover may cover and snap onto the opening of the battery box body to form a closed cavity of the battery box 131 .
  • a plurality of battery modules 200 are placed in the closed chamber after being combined in parallel, series, or mixed combination.
  • multiple batteries can be assembled to form a battery module 200, and then the multiple battery modules 200 are disposed in the battery box 131 of the battery pack 130.
  • auxiliary structural members such as cross beams may be provided between two adjacent battery modules 200 to improve the installation stability of the battery modules 200 in the battery box 131 .
  • multiple batteries may be stacked on each other and disposed in the battery box 131 of the battery pack 130 . That is to say, compared with the first embodiment, the intermediate state of the battery module 200 is eliminated. This is beneficial to reducing the mass of the battery pack 130 and increasing the energy density of the battery pack 130 .
  • the second implementation may be cell to pack (CTP) technology.
  • the above-mentioned battery box 131 can be integrated into the electrical device where the battery pack 130 is located. That is to say, the above-mentioned battery box 131 can be integrally formed with the structural components in the electrical device 100 .
  • the battery box 131 may be integrated into a local area of the chassis of the electrical device 100 .
  • a third implementation could be cell to chassis (CTC) technology.
  • the battery pack 130 may also include a bus component.
  • the bus component may collect the positive currents of multiple batteries or multiple battery modules 200 to form the positive current of the battery pack 130; the bus component may also collect multiple batteries. Or the negative current of multiple battery modules 200 forms the negative current of the battery pack 130 .
  • the bus component is used to realize electrical connection between multiple batteries or multiple battery modules 200 , such as parallel connection, series connection, or mixed connection.
  • the battery pack 130 can also output the electric energy of multiple batteries or multiple battery modules 200 outside the battery pack 130 through a conductive mechanism.
  • the electrically conductive means may be part of the bus component.
  • the battery pack 130 may also include a battery management system (battery management system, BMS) control module and cables.
  • the BMS control module is used to control the working status of multiple batteries or multiple battery modules 200 through cables.
  • the BMS control module can monitor the voltage, current, power or temperature of the battery module 200 through cables.
  • the BMS control module can disconnect the faulty battery module 200, which helps other battery modules 200 to operate normally.
  • the battery pack 130 may include a BMS control module 132 and a plurality of BMS control modules 133 .
  • the BMS control module 132 can be used to control the working status of multiple battery modules 200 .
  • Multiple BMS control modules 133 may correspond to multiple battery modules 200 of the battery pack 130 one-to-one.
  • Each battery module 200 may include multiple batteries, and the BMS control module 133 may be used to control the working status of the multiple batteries of the corresponding battery module 200 .
  • battery pack 130 may also include thermal management components. Thermal management components can be used to dissipate the heat generated by the battery pack 130 to the outside of the battery pack 130 to facilitate the battery pack 130 to operate normally at a relatively suitable temperature. There may be a cooling medium within the thermal management component. The cooling medium can flow into the battery pack 130 through the thermal management component and flow out of the battery pack 130, so that the cooling medium can take away the heat generated by the battery pack 130. In some embodiments, the cooling medium may be air or other cooling media, such as inert gas, liquid, etc., which may not be limited in the embodiments of the present application.
  • the battery pack 130 or the battery module 200 in the above embodiment may be called a battery, and the battery in the above embodiment may be called a battery cell.
  • the following uses the battery module 200 as an example to describe the embodiments provided by this application.
  • FIG. 3A is a schematic structural diagram of a battery module 200 provided by an embodiment of the present application.
  • FIG. 3B is an exploded view of the battery module 200 shown in FIG. 3A .
  • the battery module 200 may include a plurality of batteries 210 .
  • Battery 210 is used to convert chemical energy into electrical energy. In the process of generating electrical energy, the battery 210 may expand and may also generate heat.
  • Battery 210 may include an electrode assembly, an electrolyte, and a battery casing.
  • the electrode assembly and the electrolyte can be contained in the battery casing.
  • the electrode assembly may include a positive electrode piece, a negative electrode piece, and a separator.
  • the positive electrode piece and the negative electrode piece can deintercalate metal ions (such as lithium ions) to achieve energy storage and release.
  • the positive electrode plate and the negative electrode plate are the main energy storage parts of the battery 210, which can reflect the energy density, cycle performance and safety performance of the battery 210.
  • a separator may be filled between the spaced positive electrode pieces and the negative electrode pieces.
  • the separator can pass through metal ions, but the separator itself is not conductive, so the separator can separate the positive electrode piece and the negative electrode piece to prevent short circuit between the positive electrode piece and the negative electrode piece.
  • the electrolyte can be a transport carrier for metal ions between the positive electrode piece and the negative electrode piece.
  • the battery 210 may be, but is not limited to, a lithium polymer battery, a lithium ion battery, a lead-acid battery, a nickel-cadmium battery, a nickel metal-hydrogen battery, and other rechargeable batteries.
  • the shape of the battery 210 may be, for example, a strip shape or a plate shape.
  • the multiple batteries 210 in the battery module 200 may be batteries of the same model.
  • the number of batteries 210 shown in FIGS. 3A and 3B may be schematic.
  • the number of batteries 210 in the battery module 200 may be more than 2 or less than 2, that is, the battery module 200 may only include one battery 210 . This application does not specifically limit the number of batteries 210 in the battery module 200.
  • Multiple batteries 210 may be in a stacked arrangement.
  • the large surfaces 211 of two adjacent batteries 210 (the large surface 211 may refer to the surface with the largest area of the battery 210 ) may be arranged facing each other. That is, multiple batteries 210 may be stacked by the large surface 211 of the battery 210 .
  • the large side 211 of the battery 210 may be the stacking side of the battery 210 .
  • the stacking direction (Y direction) of the plurality of batteries 210 may be arranged vertically with respect to the large surface 211 of the battery 210 .
  • Electrode terminals may be disposed on the side 212 of the battery 210 (the side 212 may refer to the medium-sized surface of the battery 210) or the facet 213 (the facet 213 may refer to the smallest surface of the battery 210).
  • the positive electrode terminal may be electrically connected to the positive tab of battery 210 .
  • the negative electrode terminal may be electrically connected to the negative electrode tab of battery 210 .
  • multiple batteries 210 may be stacked by sides 212 or facets 213 of batteries 210 .
  • the battery 210 may also include oppositely disposed end plates 221 and 222 .
  • the end plates 221 and 222 can fix and protect the plurality of batteries 210 .
  • multiple batteries 210 may be clamped by the end plates 221 and 222 first, and then the end plates 221 and 222 may be fixed.
  • the end plates 221, 222 and the plurality of batteries 210 may be bundled and fixed by mounting straps.
  • the end plates 221 and 222 may be disposed opposite to the large surface 211 of the battery module 200 . That is, the end plates 221 and 222 may be disposed on both sides of the plurality of batteries 210 along the stacking direction Y of the plurality of batteries 210 .
  • the battery 210 has a relatively large tendency to expand on the large surface 211 .
  • the end plate 221 and the end plate 222 can have relatively high stiffness, which is beneficial to absorbing or resisting the expansion of the battery 210 on the large surface 211, and provides a relatively strong binding force for the battery module 200, thereby reducing the battery module 200 Possibility of overinflation.
  • the end plates 221 and 222 may be disposed opposite to the side 212 or the facet 213 of the battery module 200 .
  • the battery module 200 may also include one or more expansion detection components 230 .
  • the expansion detection component 230 may be used to detect expansion information of one or more batteries 210 .
  • the battery 210 may include an expansion detection component 230 , which may be located between the battery 210 a and the end plate 221 .
  • the battery 210 a may be a plurality of The battery 210 closest to the end plate 221 among the batteries 210 .
  • FIG. 4A is a schematic structural diagram of another battery module 200 provided by an embodiment of the present application.
  • FIG. 4B is an exploded view of the battery module 200 shown in FIG. 4A.
  • the battery module 200 may include two expansion detection assemblies 230 , one of which may be located between the battery 210 a and the end plate 221 , and the other one may be located between the battery 210 a and the end plate 221 .
  • the expansion detection component 230b may be located between the battery 210b and the end plate 222.
  • the battery 210a may be the battery 210 closest to the end plate 221 among the plurality of batteries 210.
  • the battery 210b may be the battery 210 closest to the end plate 222 among the plurality of batteries 210. .
  • the expansion detection component 230 may also be located between two adjacent batteries 210 .
  • expansion detection assembly 230 may be disposed relatively close to end plate 221 or end plate 222 . That is, the expansion detection assembly 230 may be relatively far away from the center cell of the plurality of cells 210 in the stacking direction Y of the plurality of cells 210 .
  • the center battery may refer to the middlemost battery 210 among the plurality of batteries 210 .
  • FIG. 5A shows a schematic structural diagram of an expansion detection component 230 provided by an embodiment of the present application.
  • FIG. 5A shows a schematic structural diagram of an expansion detection component 230 provided by an embodiment of the present application.
  • the expansion detection component 230 may include a pressure-bearing layer 231, a stress concentration layer 232, a deformation layer 233, and a strain gauge 234.
  • the pressure-bearing layer 231 may be adjacent to the battery 210. That is That is, the pressure-bearing layer 231 and the battery 210 may be two adjacent components.
  • the battery 210 may exert a battery expansion force on the pressure-bearing layer 231 .
  • the stress concentration layer 232 may be located between the pressure-bearing layer 231 and the deformation layer 233 .
  • the stress concentration layer 232 can withstand the battery expansion force from the pressure-bearing layer 231 and transmit the battery expansion force to the deformation layer 233 .
  • a groove 235 may be provided on a side of the deformation layer 233 away from the stress concentration layer 232 , and the groove opening 2351 is provided away from the stress concentration layer 232 .
  • the area located outside the groove opening 2351 can be used to contact the battery 210 or the end plate 221.
  • the thickness of the deformation layer 233 within the groove 235 ie, the size along the stacking direction Y of the plurality of batteries 210) may be relatively small, and the thickness of the deformation layer 233 outside the groove 235 may be relatively large. Therefore, under the action of the stress concentration layer 232, the groove bottom surface 2352 of the deformation layer 233 can be deformed relatively easily.
  • the strain gauge 234 may be disposed on the deformation layer 233 .
  • the strain gauge 234 can be fixed to the deformation layer 233 by adhesion, for example.
  • the strain gauge 234 may be used to detect the deformation amount of the groove bottom surface 2352 of the deformation layer 233 .
  • the deformation of the groove bottom surface 2352 may be elastic deformation. When the battery expansion force is reduced, the groove bottom surface 2352 can gradually return to the original state.
  • the pressure-bearing layer 231 , the stress concentration layer 232 and the deformation layer 233 may use the same material. In other embodiments, the pressure-bearing layer 231, the stress concentration layer 232 and the deformation layer 233 may use different materials. Any one of the pressure-bearing layer 231 , the stress concentration layer 232 and the deformation layer 233 can be made of a material with relatively high strength, so that the pressure-bearing layer 231 , the stress concentration layer 232 and the strain layer 233 can have a relatively high yield strength.
  • any one of the pressure-bearing layer 231, the stress concentration layer 232 and the deformation layer 233 can be made of alloy steel (such as tungsten steel, high-speed steel, carbon steel, etc.) or high-strength materials such as aluminum alloy or titanium alloy.
  • the stiffness of the groove bottom surface 2352 of the deformation layer 233 may be smaller than the stiffness of the pressure-bearing layer 231 and smaller than the stiffness of the stress concentration layer 232 .
  • the pressure-bearing layer 231 , the stress concentration layer 232 and the deformation layer 233 are made of conductive materials such as metal, in order to reduce the possibility of a short circuit between the pressure-bearing layer 231 , the stress concentration layer 232 and the deformation layer 233 and the battery 210 , the pressure-bearing layer 231 , the stress concentration layer 232 and the deformation layer 233 are The outer periphery of the concentration layer 232 and the deformation layer 233 may be provided with insulating material.
  • the projected area of the pressure-bearing layer 231 when viewed along the stacking direction Y of the plurality of batteries 210 , the projected area of the pressure-bearing layer 231 may completely or substantially coincide with the projected area of the batteries 210 . If the projected area of the pressure-bearing layer 231 is located within the projected area of the battery 210, and the area of the projected area of the pressure-bearing layer 231 is significantly different from the projected area of the battery 210, then a part of the battery 210 may be in contact with the pressure-bearing layer 231, and the remaining part may be in contact with the pressure-bearing layer 231. may be located outside the pressure-bearing layer 231.
  • the battery 210 When the battery 210 expands, the area of the battery 210 that is in contact with the pressure-bearing layer 231 can be blocked by the pressure-bearing layer 231 , thereby constraining the expansion of the battery 210 to a certain extent; while the area of the battery 210 outside the pressure-bearing layer 231 cannot. Blocked by the pressure-bearing layer 231 , the battery 210 may locally expand abnormally. It is relatively difficult to restore the local abnormal expansion of the battery 210 to normal, and it is relatively easy to cause safety accidents.
  • the projected area of the stress concentration layer 232 may be smaller than the projected area of the pressure-bearing layer 231 . In one possible case, when viewed along the stacking direction Y of the plurality of batteries 210 , the projected area of the stress concentration layer 232 may be located within the projected area of the pressure-bearing layer 231 . In one embodiment, viewed along the stacking direction Y of the plurality of batteries 210 , the center of the stress concentration layer 232 may be aligned with the center of the pressure-bearing layer 231 .
  • the projected area of the pressure-bearing layer 231 is A 1 and the projected area of the stress concentration layer 232 is A 2 .
  • the battery expansion force endured by the pressure-bearing layer 231 is F
  • the pressure P 1 ⁇ F/A 1 endured by the pressure-bearing layer 231 is F
  • the stress concentration layer 232 can withstand the battery expansion force F from the pressure-bearing layer 231, so the stress concentration layer 232 bears a pressure P 2 ⁇ F/A 2 . Since A 2 ⁇ A 1 , Therefore P 2 >P 1 . Therefore, the stress concentration layer 232 can apply a relatively large pressure to the deformation layer 233, so that the deformation amount of the deformation layer 233 is relatively obvious.
  • the deformation amounts of the deformation layer 233 can be distinguished relatively clearly, which is beneficial to improving the detection accuracy of the expansion information of the batteries 210 . If, when multiple batteries 210 exert different battery expansion forces on the pressure-bearing layer 231, the deformation amounts of the deformation layer 233 are not clearly differentiated, then the difference in the signals output by the deformation meter on the deformation layer 233 will be small, making it relatively difficult to Reflects accurate expansion information of battery 210.
  • the strain gauge 234 can be disposed on the groove bottom surface 2352 of the deformation layer 233 , and part or all of the strain gauge 234 is located between the groove bottom surface 2352 and the stress concentration layer 232 outside the relative area. That is to say, viewed along the stacking direction Y of the plurality of batteries 210 , the projected area of the groove bottom surface 2352 may include a groove bottom surface middle area and a groove bottom surface edge area, and the groove bottom surface middle area may be the same as the projected area of the stress concentration layer 232 Completely coincident, the groove bottom edge area may be located outside the projected area of the stress concentration layer 232 .
  • the strain gauge 234 can be disposed on the groove bottom surface 2352 of the deformation layer 233, and part or all of the strain gauge 234 is located in the edge area of the groove bottom surface. In one possible case, the separation distance between the deformation layer 233 and the stress concentration layer 232 may be relatively narrow. When the deformation layer 233 and the stress concentration layer 232 are integrally formed, it may be relatively convenient to provide the strain gauge 234 on a side of the deformation layer 233 away from the stress concentration layer 232 .
  • the strain gauge 234 may be disposed on the end surface 237 of the deformation layer 233 close to the stress concentration layer 232 , and part or all of the strain gauge 234 is located outside the area of the end surface 237 opposite to the stress concentration layer 232 .
  • the end face 237 may be an end face of the deformation layer 233 adjacent to the battery 210 .
  • the end face 237 may be disposed face to face with the stacking face of the battery 210 .
  • the end surface 237 may be disposed perpendicularly to the stacking direction Y of the plurality of batteries 210 .
  • the strain gauge 234 may be disposed between the deformation layer 233 and the stress concentration layer 232, and some or all of the strain gauge 234 may be located at the edge of the deformation region.
  • the projection area of the deformation area on the end surface 237 can completely overlap with the projection area of the groove bottom surface 2352; when viewed along the stacking direction Y of multiple batteries 210, the projection area of the deformation area
  • the projection area includes a middle projection area and an edge projection area; the middle projection area is the projection area of the middle part of the deformation area, and the middle projection area completely coincides with the projection area of the stress concentration layer 232; the edge projection area is the edge part of the deformation area
  • the projection area of the edge is located outside the projection area of the stress concentration layer 232 .
  • the middle area of the above-mentioned deformation area may be arranged opposite to the middle area of the groove bottom surface, and the edge area of the above-mentioned deformation area may be arranged opposite to the edge area of the groove bottom surface.
  • the projected area of the strain gauge 234 may partially coincide with the edge projected area.
  • the pressure-bearing layer 231, the stress concentration layer 232 and the deformation layer 233 of the expansion detection component 230 can be obtained by assembly.
  • the pressure-bearing layer 231, the stress concentration layer 232, and the deformation layer 233 can be assembled by one or more of the following: pasting, riveting, welding, and plugging.
  • At least two of the pressure-bearing layer 231 , the stress concentration layer 232 and the deformation layer 233 of the expansion detection component 230 can be obtained by integral molding.
  • the pressure-bearing layer 231, the stress concentration layer 232 and the deformation layer 233 are formed by integral molding.
  • the pressure-bearing layer 231 and the stress concentration layer 232 are obtained by integral molding, and the deformation layer 233 and the stress concentration layer 232 are obtained by assembly.
  • the deformation layer 233 and the stress concentration layer 232 are integrally formed. To, the pressure-bearing layer 231 and the stress concentration layer 232 are obtained by assembly.
  • FIGS. 6A-6C show schematic structural diagrams of several strain gauges 234 provided by embodiments of the present application. It should be understood that the strain gauge 234 set forth herein may not be limited to the strain gauge 234 shown in FIGS. 6A-6C.
  • Strain gauge 234 shown in Figure 6A may be a single resistance strain gauge.
  • the detection principle of the single resistance strain gauge is that when the single resistance strain gauge is stretched, the length of the single resistance strain gauge can change, and then the resistance of the single resistance strain gauge can change.
  • the resistance of a single resistance strain gauge can reflect the change in length of a single resistance strain gauge.
  • a single resistance strain gauge may be used, for example, to detect strain along the length of a single resistance strain gauge.
  • the strain gauge 234 shown in Figure 6B may be a parallel gate full bridge strain gauge 234.
  • the parallel grid full bridge strain gauge may include strain grid 234a, strain grid 234b, strain grid 234c, and strain grid 234d.
  • the length directions of the strain grids 234a, 234b, 234c and 234d may be parallel to each other.
  • the directions in which the strain grids 234a, 234b, 234c and 234d detect strains can be parallel to each other.
  • the strain grids 234a, 234b, 234c, and 234d are electrically connected in a full-bridge mode.
  • the circuit including the strained gate 234a, the strained gate 234b, the strained gate 234c, and the strained gate 234d may be a full-bridge circuit.
  • the direction of strain is parallel to the length direction of strain grid 234a
  • strain grid 234a and strain grid 234b detect the deformation amount at the same position
  • strain grid 234c and strain grid 234d detect the deformation amount at the same position.
  • the voltage difference between the strain grid 234a and the strain grid 234b can both be V 1
  • the voltage difference between the strain grid 234c and the strain grid 234d can both be V 2
  • the total voltage difference between the strain gauge 234 is 2 ⁇ (V 1 -V 2 ).
  • the parallel grid full-bridge strain gauge 234 is beneficial to reducing the influence of temperature, DC bias and other factors on the detection results.
  • the strain gauge 234 shown in Figure 6C may be a vertical grid full bridge strain gauge.
  • the vertical grid full bridge strain gauge may include strain grid 234a', strain grid 234b', strain grid 234c', and strain grid 234d'.
  • the length directions of the strain grid 234a' and the strain grid 234b' may be perpendicular to each other.
  • the length directions of the strain grid 234a' and the strain grid 234d' may be parallel to each other.
  • the length directions of the strain grid 234b' and the strain grid 234c' may be parallel to each other. Therefore, the direction in which strain grid 234a' detects strain can be perpendicular to the direction in which strain grid 234b' detects strain.
  • strain grid 234a' detects strain can be parallel to the direction in which strain grid 234d' detects strain.
  • Strain grid 234b' The direction in which the strain is detected can be parallel to the direction in which the strain grid 234c' detects the strain.
  • the direction in which the strain grid 234c' detects the strain can be perpendicular to the direction in which the strain grid 234d' detects the strain.
  • the strain grid 234a', the strain grid 234b', the strain grid 234c', and the strain grid 234d' are electrically connected in a full-bridge mode.
  • the strain grid 234a' and the strain grid 234b' detect the deformation amount at the same position
  • the strain grid 234c' and the strain grid 234d' detect the deformation amount at the same position.
  • the voltage difference between the strain grid 234a' and the strain grid 234d' can be V 1
  • the voltage difference between the strain grid 234b' and the strain grid 234c' can both be 0, then the total voltage difference of the strain gauge 234 is 2 ⁇ V 1 .
  • the vertical grid full-bridge strain gauge 234 is beneficial to improve detection sensitivity.
  • FIG. 7A and FIG. 7B The principle of the expansion detection component 230 detecting the expansion information of the battery 210 will be described below with reference to FIGS. 7A and 7B .
  • FIG. 7A shows a schematic structural diagram of the expansion detection assembly 230 when it is in an initial state.
  • the overall amount of expansion of the one or more batteries 210 is relatively small or negligible. Therefore, the deformation layer 233 may not deform or deform a small amount.
  • the minimum separation distance between the deformation layer 233 and the pressure-bearing layer 231 may be the same as the thickness of the stress concentration layer 232 (ie, the size of the stress concentration layer 232 in the stacking direction Y of the plurality of batteries 210), or the deformation
  • the minimum separation distance between layer 233 and pressure-bearing layer 231 may be slightly less than the thickness of stress concentration layer 232 .
  • strain gauge 234 may be provided before end plate 221 and end plate 222 may clamp battery 210 .
  • Expansion detection assembly 230 is placed.
  • the expansion detection component 230 can withstand the pre-tightening force from the end plate 221 and the end plate 222, so that the deformation layer 233 can undergo slight deformation.
  • the signal output by the strain gauge 234 can reflect the strain of the deformation layer 233 . That is to say, the expansion detection component 230 may have the function of detecting the pre-tightening force, which is beneficial to keeping the clamping force of the battery 210 within an appropriate range.
  • the expansion detection assembly 230 without the strain gauge 234 may be disposed within the battery module 200 before the end plates 221 and 222 can clamp the battery 210 .
  • the expansion detection component 230 can withstand the pre-tightening force from the end plate 221 and the end plate 222, so that the deformation layer 233 can undergo slight deformation.
  • Strain gauge 234 may be disposed on expansion detection assembly 230 after end plate 221 and end plate 222 may clamp battery 210 .
  • the strain gauge 234 basically cannot detect the amount of strain of the deformation layer 233 caused by the battery clamping force, which is beneficial to reducing the impact of the clamping force on the battery expansion force detection.
  • FIG. 7B shows a schematic structural diagram of the expansion detection assembly 230 when it is in a detection state.
  • the expansion detection component 230 may be in a detection state.
  • one or more batteries 210 may exert a battery expansion force on the pressure-bearing layer 231 .
  • the pressure-bearing layer 231 and the stress concentration layer 232 tend to move toward a certain end plate 221 of the battery module 200 .
  • 3A and 4A the distance between the end plate 221 and the end plate 222 of the battery module 200 is relatively fixed, so the position of the end surface 236 of the deformation layer 233 close to the end plate 221 in the battery module 200 can be relatively fixed.
  • the displacement of the end surface 236 of the deformation layer 233 close to the end plate 221 in the stacking direction Y of the plurality of batteries 210 is relatively small or even negligible.
  • the groove bottom surface 2352 of the deformation layer 233 tends to protrude toward the end plate 221. That is to say, the groove bottom surface 2352 of the deformation layer 233 may be stretched, bent, warped, etc. deformed.
  • the deformation amount of the region of the groove bottom surface 2352 connected to the stress concentration layer 232 may be relatively small.
  • the remaining area of the groove bottom surface 2352 may be relatively deformed. In this case, the minimum separation distance between the deformation layer 233 and the pressure-bearing layer 231 may be smaller than the thickness of the stress concentration layer 232 .
  • the thickness of the expansion detection component 230 shown in FIGS. 5A and 5B is relatively small, and has a relatively small impact on the energy density of the battery module 200 .
  • the expansion detection component 230 can detect the static pressure of the battery module 200 in normal charging and discharging scenarios. At this time, the battery expansion force of the battery module 200 can be relatively small.
  • the expansion detection component 230 can detect dynamic pressure changes of the battery module 200 in a scenario where the battery expansion force increases rapidly.
  • the strain gauge 234 can detect the strain amount of the groove bottom surface 2352, expansion information of one or more batteries 210 can be determined based on the strain amount output by the strain gauge 234.
  • the amount of strain output by the strain gauge 234 may reflect the stress on the bottom surface of the groove 2352, which may further reflect the battery expansion force of one or more batteries 210.
  • the amount of strain output by the strain gauge 234 may reflect the amount of expansion of one or more batteries 210 .
  • the specific form of expansion of the battery 210 may be different.
  • the center of expansion of battery 210 is located at the center or center of gravity of battery 210 .
  • the expansion center of the battery 210 is offset from the center or center of gravity of the battery 210 .
  • the expansion detection component 230 can deform in response to the battery expansion force, so that in scenarios with complex and diverse expansion amounts, the expansion detection component 230 can take into account various battery expansion situations. In other words, the detection of battery expansion force is not limited to the specific battery expansion amount.
  • the cross-sectional shape of the groove 235 perpendicular to the stacking direction Y of the plurality of batteries 210 may match the cross-sectional shape of the stress concentration layer 232 perpendicular to the stacking direction Y of the plurality of batteries 210 .
  • both the groove 235 and the stress concentration layer 232 may have a rectangular cross section perpendicular to the stacking direction Y of the plurality of batteries 210 .
  • the cross sections of the groove 235 and the stress concentration layer 232 perpendicular to the stacking direction Y of the plurality of cells 210 may have other shapes.
  • groove 235 The cross section of the stress concentration layer 232 perpendicular to the stacking direction Y of the plurality of batteries 210 may be circular.
  • the cross-sections of the groove 235 and the stress concentration layer 232 perpendicular to the stacking direction Y of the plurality of batteries 210 may be elliptical.
  • the cross-sectional shapes of the groove 235 and the stress concentration layer 232 may not be limited to the embodiments provided in this application.
  • the projected area of the stress concentration layer 232 when viewed along the stacking direction Y of the plurality of batteries 210 , the projected area of the stress concentration layer 232 is equal to The ratio of the projected area of the pressure-bearing layer 231 is relatively small. According to the above-mentioned principle, the strength of the stress concentration layer 232 acting on the deformation layer 233 is relatively large. Therefore, the deformation amount of the groove bottom surface 2352 of the deformation layer 233 may be relatively large.
  • the ratio of the projected area of the stress concentration layer 232 to the projected area of the pressure-bearing layer 231 can be adapted to the deformation amount of the deformation layer 233 . That is to say, the size, shape, etc. of the stress concentration layer 232 and the pressure-bearing layer 231 can be adapted to the deformation amount of the deformation layer 233.
  • the deformation amount of the deformation layer 233 can be relatively small.
  • the strain gauge 234 can be used to detect relatively large battery expansion forces.
  • the deformation amount of the deformation layer 233 can be relatively large under the action of a relatively small battery expansion force.
  • Strain gauges 234 may be used to detect relatively small cell expansion forces.
  • the ratio of the projected area of the stress concentration layer 232 to the projected area of the groove bottom surface 2352 of the deformation layer 233 can be determined by the deformation amount of the deformation layer 233. adaptation. That is to say, the size, shape, etc. of the groove bottom surface 2352 can be adapted to the deformation amount of the deformation layer 233.
  • the groove bottom surface 2352 of the deformation layer 233 has a relatively large deformable area. Therefore, under the action of the battery expansion force, the deformation amount of the groove bottom surface 2352 of the deformation layer 233 can be spread evenly by the relatively large area, and thus the deformation amount of the groove bottom surface 2352 of the deformation layer 233 can be relatively small.
  • strain gauge 234 may be used to detect relatively large battery expansion forces.
  • the groove bottom surface 2352 of the deformation layer 233 has a relatively small deformable area. Therefore, under the action of the battery expansion force, the deformation amount of the groove bottom surface 2352 of the deformation layer 233 can be limited to a relatively small area, and then the deformation amount of the groove bottom surface 2352 of the deformation layer 233 can be relatively large. In this case, strain gauge 234 may be used to detect relatively small cell expansion forces.
  • the detection range of the expansion detection component 230 may also be related to the depth of the groove 235 of the deformation layer 233 and the total thickness of the deformation layer 233 .
  • the depth of the groove 235, the total thickness of the deformation layer 233, and the ratio of the depth of the groove 235 to the total thickness of the deformation layer 233 it is beneficial to enable the expansion detection component 230 to have a relatively appropriate detection range and detection accuracy.
  • the thickness of the groove bottom surface 2352 of the deformation layer 233 is relatively large, the rigidity of the groove bottom surface 2352 of the deformation layer 233 is relatively large, and the groove bottom surface 2352 of the deformation layer 233 is relatively difficult to deform.
  • the groove bottom surface 2352 of the deformation layer 233 can have relatively more deformation space in the stacking direction Y of the plurality of batteries 210, which is beneficial to increasing the detection range of the expansion detection component 230.
  • the thickness of the groove bottom surface 2352 of the deformation layer 233 is small, the rigidity of the groove bottom surface 2352 of the deformation layer 233 is relatively small, and the groove bottom surface 2352 of the deformation layer 233 is relatively easy to deform. It is conducive to relatively sensitive detection of changes in battery expansion force within the effective range.
  • the detection range of the strain gauge 234 may be adapted to the deformation amount of the groove bottom surface 2352 of the deformation layer 233 .
  • the groove bottom surface 2352 of the deformation layer 233 is in contact with the end plate 221, or when the groove bottom surface 2352 of the deformation layer 233 is flush with the groove opening 2351 of the deformation layer 233, the groove bottom surface 2352 The amount of deformation may reach the maximum value. If the deformation amount of the groove bottom surface 2352 exceeds the detection range of the strain gauge 234, the strain gauge 234 cannot accurately output the expansion information of the battery 210. If the battery 210 continues to expand, the deformation amount of the groove bottom surface 2352 of the deformation layer 233 will not change significantly.
  • the strain gauge 234 cannot accurately output the expansion information of the battery 210 .
  • the strain detection range of the strain gauge 234 to the maximum deformation amount of the deformation layer 233 , it is helpful to select a suitable strain gauge 234 .
  • the battery module 200 can be configured with two expansion detection assemblies 230 with different structures.
  • the two expansion detection assemblies 230 can be used for different expansion force ranges.
  • the expansion detection assembly 230a can correspond to a relatively small expansion force range.
  • the expansion force range of the expansion detection component 230b can correspond to a relatively large expansion force range.
  • the expansion information of the battery module 200 can be determined based on the result output by the expansion detection component 230a.
  • the expansion information of the battery module 200 can be determined based on the result output by the expansion detection component 230b.
  • the battery expansion force of the battery 210 fluctuates in the range of approximately 0 to 20 kN.
  • the size of the end surface of the pressure-bearing layer 231 opposite to the large surface 211 of the battery 210 may be 148mm*102.5mm. That is to say, viewed along the stacking direction Y of the plurality of batteries 210, the size of the projected area of the pressure-bearing layer 231 may be 148mm*102.5mm.
  • the thickness of the pressure-bearing layer 231 may be, for example, 2 mm.
  • the thickness of the pressure-bearing layer 231 is relatively appropriate, which can be used to keep the stiffness of the pressure-bearing layer 231 within a reasonable range, which is beneficial to reducing the deformation of the pressure-bearing layer 231 and allowing the battery expansion force to pass through the bottom surface of the groove of the deformation layer 233 as much as possible.
  • the deformation amount of 2352 is reflected; the thickness of the pressure-bearing layer 231 is relatively appropriate, which is also conducive to making the overall space occupied by the expansion detection assembly 230 relatively small.
  • the size of the end surface of the stress concentration layer 232 opposite to the large surface 211 of the battery 210 may be 118mm*72.5mm. That is to say, viewed along the stacking direction Y of the plurality of batteries 210, the size of the projected area of the pressure-bearing layer 231 may be 118mm*72.5mm.
  • the thickness of the stress concentration layer 232 may be, for example, 1 mm.
  • the thickness of the stress concentration layer 232 is relatively appropriate, which can be used to keep the stiffness of the stress concentration layer 232 within a reasonable range, which is beneficial to reducing the deformation of the stress concentration layer 232 and allowing the battery expansion force to pass through the groove bottom of the deformation layer 233 as much as possible.
  • the deformation amount of 2352 is reflected; the thickness of the stress concentration layer 232 is relatively appropriate, which is also conducive to making the overall space occupied by the expansion detection component 230 relatively small.
  • the thickness of the stress concentration layer 232 is also used to limit the contact between the pressure-bearing layer 231 and the deformation layer 233 .
  • the pressure-bearing layer 231 may not be in contact with the deformation layer 233 Therefore, the battery expansion force can be transmitted substantially or completely through the stress concentration layer 232 to the deformation layer 233 .
  • the pressure-bearing layer 231 can contact the deformation layer 233, so the battery expansion force is in addition to the stress.
  • the concentration layer 232 transfers to the deformation layer 233, and also It is transmitted to the deformation layer 233 through the pressure-bearing layer 231 .
  • the deformation amount of the groove bottom surface 2352 of the deformation layer 233 may not accurately reflect the battery expansion force.
  • the size of the end surface 237 of the deformation layer 233 may be 148mm*102.5mm. That is to say, viewed along the stacking direction Y of the plurality of batteries 210, the size of the projected area of the deformation layer 233 may be 148mm*102.5mm.
  • the thickness of the deformation layer 233 outside the groove 235 may be 3 mm.
  • the thickness of the deformation layer 233 in the groove 235 may be 2 mm. That is, the depth of the groove 235 may be 1 mm.
  • the size of the groove opening 2351 may be 128mm*82.5mm. In another embodiment, the size of the groove opening 2351 may be 138mm*92.5mm.
  • the thickness of strain gauge 234 may be less than the depth of groove 235 . Thus, the total thickness of the expansion detection assembly 230 may not exceed 6 mm.
  • FIGS. 10A to 10D illustrate simulation results in which the expansion detection assembly 230 is subjected to the battery expansion force of one or more batteries 210 .
  • the battery expansion force can be 20kN.
  • the specific structural dimensions of the expansion detection component 230 may refer to the above.
  • the displacement simulation result of the expansion detection component 230 shown in FIG. 10A can be obtained.
  • the battery 210 expands, the battery 210 can only exert a battery expansion force on the pressure-bearing layer 231 , causing the pressure-bearing layer 231 and the stress concentration layer 232 to move toward the deformation layer 233 .
  • the deformation layer 233 is limited by the end plate 221, and the overall displacement of the deformation layer 233 is relatively small.
  • the displacement amount of the pressure-bearing layer 231 and the stress concentration layer 232 in the stacking direction Y of the plurality of batteries 210 may be less than 0.2 mm. Therefore, the pressure-bearing layer 231 will not contact the deformation layer 233 .
  • the displacement simulation result of the expansion detection assembly 230 shown in FIG. 10B can be obtained.
  • the area of the groove bottom surface 2352 of the deformation layer 233 that is opposite to the stress concentration layer 232 has a tendency to move away from the pressure-bearing layer 231.
  • the edge area of the deformation layer 233 is limited by the end plate 221, and the displacement of the edge area of the deformation layer 233 is relatively small.
  • the area located between the edge area of the deformation layer 233 and the area of the groove bottom surface 2352 connected to the stress concentration layer 232, that is, the edge area of the groove bottom surface 2352, may undergo tensile deformation.
  • the protruding height of the groove bottom surface 2352 in the stacking direction Y of the plurality of batteries 210 may be less than 0.15 mm. Therefore, the groove bottom surface 2352 will not contact the end plate 231 or will not be flush with the groove opening 2351.
  • FIG. 10C shows simulation results of the strain tensor of the expansion detection assembly 230 along the X direction.
  • FIG. 10D shows simulation results of the strain tensor of the expansion detection assembly 230 along the Z direction.
  • the cross-sectional shape of the groove bottom surface 2352 may be rectangular. By dividing the edge area of the groove bottom surface 2352, edge sub-area 2352a, edge sub-area 2352b, edge sub-area 2352c and edge sub-area 2352d can be obtained.
  • the edge sub-region 2352a and the edge sub-region 2352c may be disposed in parallel relative to the long side of the groove 235, and the edge sub-region 2352b and the edge sub-region 2352d may be disposed in parallel relative to the short side of the groove 235.
  • the long side of the groove 235 may be parallel to the X direction, and the short side of the groove 235 may be parallel to the Z direction.
  • the strain tensor in the X direction of the center position of the edge sub-region 2352a and the center position of the edge sub-region 2352c is relatively small.
  • the strain tensor in the Z direction is relatively large at the center position of the edge sub-region 2352a and the center position of the edge sub-region 2352c.
  • the strain tensor in the X direction is relatively large at the end position of the edge sub-region 2352a and the end position of the edge sub-region 2352c.
  • the strain tensor in the Z direction is relatively large at the end position of the edge sub-region 2352a and the end position of the edge sub-region 2352c.
  • the strain tensors in the X direction and the Z direction at the center position of the edge sub-region 2352a and the center position of the edge sub-region 2352c are approximately 1000 ⁇ .
  • the strain tensor in the Z direction of the center position of the edge sub-region 2352b and the center position of the edge sub-region 2352d is relatively small.
  • the response of the center position of the edge sub-region 2352b and the center position of the edge sub-region 2352d in the X direction The variable tensor is relatively large.
  • the strain tensor in the Z direction is relatively large at the end position of the edge sub-region 2352b and the end position of the edge sub-region 2352d.
  • the strain tensor in the Z direction is relatively large at the end position of the edge sub-region 2352b and the end position of the edge sub-region 2352d.
  • the stress on the four corners of the groove bottom surface 2352 may be greater than the stress on other areas of the groove bottom surface 2352 .
  • the stress at the center position of the edge sub-region 2352a and the center position of the edge sub-region 2352c may be approximately 100 to 300 MPa. Since the center positions of the edge sub-region 2352a and the center positions of the edge sub-region 2352c bear relatively small stress, the center positions of the edge sub-region 2352a and the center positions of the edge sub-region 2352c are more likely to undergo elastic recovery. This is beneficial to realizing the expansion detection component 230 working in multiple cycles.
  • FIGS. 11A to 11D Observing the expansion detection assembly 230 along the stacking direction Y of the plurality of batteries 210, the schematic structural diagrams shown in FIGS. 11A to 11D can be obtained.
  • FIGS. 11A to 11D show schematic structural diagrams of the grooves 235 of the deformation layer 233 .
  • the area enclosed by the dotted box in Figures 11A to 11D shows the projection area of the stress concentration layer 232 on the groove bottom surface 2352, that is, the middle area of the groove bottom surface; the area filled with diagonal lines in Figures 11A to 11D shows The area of the groove bottom surface 2352 surrounding the outer periphery of the projection area of the stress concentration layer 232 is the above-mentioned groove bottom surface edge area.
  • the strain gauge 234 may be disposed in the edge area of the groove bottom surface.
  • FIGS. 11A to 11D show schematic structural diagrams of the end surface 236 of the deformation layer 233 close to the stress concentration layer 232 .
  • the area enclosed by the dotted box in FIGS. 11A to 11D shows the area of the end face 236 connected to the stress concentration layer 232 , that is, the middle part of the above-mentioned deformation area; the area filled with oblique lines in FIGS. 11A to 11D shows The area of the end surface 236 located outside the stress concentration layer 232 is the edge portion of the deformation area. That is, the strain gauge 234 may be provided at an edge portion of the deformation region.
  • strain gauge 234 is arranged in the groove 235 .
  • the specific position of the strain gauge 234 on the end surface 236 of the deformation layer 233 close to the stress concentration layer 232 may refer to the embodiment in which the strain gauge 234 is disposed in the groove 235 .
  • the strain gauge 234 may be disposed on the axis of symmetry of the groove 235 .
  • the groove 235 may be symmetrical about the symmetry axis x and the symmetry axis z.
  • the symmetry axis x and the symmetry axis z can be set relatively vertically.
  • the symmetry axis x and the symmetry axis z may be arranged vertically with respect to the stacking direction Y of the plurality of batteries 210 .
  • the axis of symmetry x may be disposed parallel to the long side of the groove bottom surface 2352.
  • the axis of symmetry y may be arranged parallel to the short side of the groove bottom surface 2352.
  • Expansion detection assembly 230 may include strain gauges 2341 , 2342 , 2343 and 2344 strain gauges.
  • the strain gauge 2341 and the strain gauge 2343 may be disposed on the symmetry axis z and located on both sides of the groove 235 respectively.
  • Strain gauges 2342 and 2344 may be disposed on the symmetry axis x and located on both sides of the groove 235 respectively.
  • the strain gauge 2341 and the strain gauge 2343 can be mainly used to detect the strain on the symmetry axis z, thereby reflecting the component of the battery expansion force in the symmetry axis z or the Z direction.
  • the signal values output by the strain gauges 2341 and 2343 can also be used to offset errors introduced by the strain gauges 2341 and 2343 themselves.
  • the strain gauges 2342 and 2344 may be mainly used to detect the strain on the symmetry axis x, thereby reflecting the component of the battery expansion force in the symmetry axis x or the X direction.
  • the signal values output by the strain gauges 2342 and 2344 can also be used to offset errors introduced by the strain gauges 2342 and 2344 themselves.
  • the strain gauge 234 can be used to output the battery expansion force in the direction of the symmetry axis, which is beneficial to obtaining expansion information in the direction of the symmetry axis.
  • the strain gauge 234 may be positioned near a corner of the groove bottom surface 2352 .
  • the edge area of the groove bottom surface 2352 may include an edge sub-area 2352a, an edge sub-area 2352b, an edge sub-area 2352c and an edge sub-area 2352d.
  • the edge sub-region 2352a and the edge sub-region 2352c may be disposed in parallel relative to the long side of the groove 235, and the edge sub-region 2352b and the edge sub-region 2352d may be disposed in parallel relative to the short side of the groove 235.
  • the boundary area of edge sub-area 2352a and edge sub-area 2352d may be corner 1 of groove bottom surface 2352.
  • the boundary area of edge sub-area 2352a and edge sub-area 2352b may be corner 2 of groove bottom surface 2352.
  • the boundary area of edge sub-area 2352b and edge sub-area 2352c may be corner 3 of groove bottom surface 2352.
  • the boundary area of edge sub-area 2352d and edge sub-area 2352d may be corner 4 of groove bottom surface 2352.
  • Expansion detection assembly 230 may include strain gauges 2341 , 2342 , 2343 and 2344 strain gauges.
  • the strain gauge 2341 may be disposed in the edge sub-region 2352a and close to the corner 1 of the groove bottom surface 2352.
  • Strain gauge 2342 may be disposed in edge sub-region 2352a and proximate corner 2 of groove bottom surface 2352.
  • the strain gauge 2343 may be disposed in the edge sub-region 2352c and close to the corner 3 of the groove bottom surface 2352.
  • Strain gauge 2344 may be disposed in edge sub-region 2352c and proximate corner 4 of groove bottom surface 2352.
  • the strain gauge 2341 may be disposed in the edge sub-region 2352d and proximate corner 1 of the groove bottom surface 2352.
  • Strain gauge 2342 may be disposed in edge sub-region 2352b and proximate corner 2 of groove bottom 2352.
  • the strain gauge 2343 may be disposed in the edge sub-region 2352b and close to the corner 3 of the groove bottom surface 2352.
  • Strain gauge 2344 may be disposed in edge sub-region 2352d and proximate corner 4 of groove bottom surface 2352.
  • the strain at the corner of the groove bottom surface 2352 has both a component along the X direction and a component along the Z direction.
  • the signal values output by the strain gauges 2341 , 2342 , 2343 and 2344 may reflect the total battery expansion force of one or more batteries 210 .
  • the strain at the corners of the groove base 2352 is related to the peak deformation of the groove base 2352.
  • the deformation peak value may have relatively large instability.
  • the deformation peak value may be affected by local special deformation. Therefore, the deformation peak value may not relatively accurately reflect the overall stress condition of the groove bottom surface 2352. Since the position of the strain gauge 234 on the groove bottom surface 2352 is at a certain distance from the angle of the groove bottom surface 2352, it is beneficial to reduce the possibility of the strain gauge 234 detecting local special deformation and reduce the impact of local special deformation on the overall expansion information.
  • expansion detection assembly 230 may include a greater or lesser number of strain gauges 234.
  • the expansion detection component 230 may only include the strain gauge 2341 and the strain gauge 2342 in the embodiment shown in FIG. 11A ; wherein the strain gauge 2341 may be mainly used to detect the expansion on the symmetry axis z. Strain, thereby reflecting the component of the battery expansion force in the symmetry axis z or Z direction; the strain gauge 2342 can be mainly used to detect the strain on the symmetry axis x, thereby reflecting the component of the battery expansion force in the symmetry axis x or X direction. Partial force.
  • expansion detection assembly 230 may include a strain gauge 2345.
  • the strain gauge 2345 may be disposed at the interface area between the edge sub-region 2352a and the edge sub-region 2352d, that is, the strain gauge 2345 is disposed at the corner 1 of the groove bottom surface 2352.
  • the strain gauge 2345 can be used to detect the overall deformation of the groove bottom surface 2352, and the signal value output by the strain gauge 2345 can reflect the total battery expansion force of one or more batteries 210.
  • FIG. 12 shows how the strain gauges 2341 to 2344 in the embodiment shown in FIG. 11A output signals.
  • the signal amount output by the strain gauges 2341 to 2344 may be substantially linearly related to the battery expansion force of the battery 210 . That is, based on the signal amount of the strain gauge 234 and the relationship between the signal amount of the strain gauge 234 and the battery expansion force shown in FIG. 12 , the battery expansion force of the battery 210 can be determined.
  • FIG. 13 shows a schematic structural diagram of an expansion detection component 230 provided by an embodiment of the present application.
  • the expansion detection component 230 may include a feed terminal and a ground terminal.
  • the expansion detection component 230 may form a loop through the feed terminal and the ground terminal. road.
  • the feed terminal and the ground terminal may be used to feed components within the expansion detection assembly 230 .
  • Swell detection assembly 230 may also include one or more strain gauges 234.
  • Strain gauge 234 may include an output S+ and an output S-.
  • the voltage difference between the output terminal S+ and the output terminal S-, and the current conducted between the output terminal S+ and the output terminal S- can reflect the resistance of the strain gauge 234.
  • the output terminal S- may be the ground terminal of the strain gauge 234 .
  • expansion detection assembly 230 may include strain gauges 2341 , 2342 , 2343 and 2344 strain gauges.
  • the strain gauges 2341, 2342, 2343, and 2344 may correspond to the strain gauges 2341, 2342, 2343, and 2344 shown in FIG. 11A or 11B.
  • the expansion detection component 230 may also include an analog front end (AFE). Signals from strain gauge 234 may be input to the AFE.
  • the AFE may include an analog-to-digital (AD) converter for converting the analog signal output by the strain gauge 234 into a digital signal.
  • AD analog-to-digital
  • expansion detection assembly 230 may also include a control unit.
  • the control unit may be, for example, a microcontroller unit (MCU).
  • the control unit may be used to process the signal output by the strain gauge 234 .
  • the control unit can perform correction, DC removal, noise signal removal, etc. on the signal output by the strain gauge 234 .
  • the noise signal may be, for example, an error signal that is affected by temperature, prestress, etc.
  • the expansion detection component 230 may output the expansion information of the battery through the control unit.
  • the expansion detection component 230 may output the expansion information of the battery 210 to the BMS control module 132 or the BMS control module 133 shown in FIG. 2 .
  • Figure 14 is a schematic flow chart of a method for obtaining battery expansion force provided by an embodiment of the present application.
  • the expansion information is used to indicate the battery expansion force.
  • the input voltage to strain gauge 234 may be constant. After the strain gauge 234 is deformed, the resistance of the strain gauge 234 may change, the current conducted by the strain gauge 234 may change, and the voltage difference between the output terminal S+ and the output terminal S- of the strain gauge 234 may change.
  • the processing module (such as the BMS control module 132 or the BMS control module 133 shown in Figure 2) that executes the method shown in Figure 14 can be based on the voltage difference of the strain gauge 234 and the voltage difference of the strain gauge 234. -The relationship between the battery expansion force and the battery expansion force.
  • the expansion detection parameter may indicate the relationship between the voltage difference of the strain gauge 234 and the battery expansion force.
  • the expansion detection parameters may include multiple voltage differences of the strain gauge 234 and multiple battery expansion forces, and the multiple voltage differences of the strain gauge 234 correspond to multiple battery expansion forces in a one-to-one manner.
  • the signal shown by the strain gauge 234 may be converted into a strain quantity.
  • the expansion detection parameters may include the amount of strain detected by the strain gauge 234 - the slope of the cell expansion force.
  • the expansion detection parameters may include multiple strain values detected by the strain gauge 234 and multiple battery expansion forces. The multiple strain values of the strain gauge 234 correspond to the multiple battery expansion forces in a one-to-one manner.
  • 1402 may be performed in detection mode.
  • the method of obtaining the battery expansion force may also include: 1403.
  • the strain gauge 234 Before using the strain gauge 234, the strain gauge 234 may be calibrated. By applying a preset force to the expansion detection component 230, the strain gauge 234 of the expansion detection component 230 can detect deformation. The signal output by the strain gauge 234 can be matched to the preset force. According to the relationship between the signal output by the strain gauge 234 and the preset force, it can be determined Set expansion detection parameters.
  • the expansion detection parameters may be stored in memory. When the strain gauge 234 is operating normally, by reading the expansion detection parameters from the memory, the battery expansion force corresponding to the signal output by the strain gauge 234 can be determined.
  • the expansion detection component 230 when the battery 210 has not left the factory, the expansion detection component 230 can enter the calibration mode; when the battery 210 leaves the factory, the expansion detection component 230 can change from the calibration mode to the detection mode; when the battery 210 is in a maintenance state, The expansion detection component 230 can change from the detection mode to the calibration mode; after the battery 210 is repaired, the expansion detection component 230 can change from the calibration mode to the detection mode.
  • the control unit of the expansion detection component 230 can be used to update the mode identifier, and the mode identifier can be used to indicate that the expansion detection component 230 is in the calibration mode or the detection mode.
  • the expansion detection component 230 may include the strain gauge 2341, the strain gauge 2342, the strain gauge 2343, and the strain gauge 2344 shown in Figure 11A.
  • the method of obtaining the battery expansion force may also include: according to the strain gauge 2341, the strain gauge 2342, the signals output by the strain gauges 2343 and 2344 determine the acting position of the battery expansion force, or calibrate the expansion detection parameters related to the center position of the expansion detection component 230.
  • strain gauges 2341, 2342, 2343, and 2344 refer to the embodiment shown in FIG. 11A.
  • P 0 shows the center position of the expansion detection assembly 230 .
  • the center position of the expansion detection component 230 may correspond to the center or center of gravity of the expansion detection component 230 , the center or center of gravity of the end plate 221 , or the center or center of gravity of the battery 210 .
  • the projection of the center or center of gravity of the battery 210 on the expansion detection component 230 may be aligned with the center position of the expansion detection component 230 .
  • the force F 0 may be applied at the center position P 0 of the expansion detection assembly 230 .
  • Strain gauge 2341, strain gauge 2342, strain gauge 2343 and strain gauge 2344 can output signals, which are S 1 (F 0 ,P 0 ), S 2 (F 0 ,P 0 ), S 3 (F 0 ,P 0 ) respectively. ,S 4 (F 0 ,P 0 ).
  • a 1 , A 2 , A 3 and A 4 may be the strain gauge coefficients of the strain gauge 2341 , the strain gauge 2342 , the strain gauge 2343 and the strain gauge 2344 respectively.
  • the strain gage coefficient is generally related to the properties of the strain gage 234 itself.
  • z 1 , x 2 , z 3 and x 4 may be position information of the strain gauge 2341 , the strain gauge 2342 , the strain gauge 2343 and the strain gauge 2344 respectively on the expansion detection component 230 .
  • the edge area of the groove bottom surface 2352 may include an edge sub-area 2352a, an edge sub-area 2352b, an edge sub-area 2352c, and an edge sub-area 2352d.
  • the edge sub-region 2352a and the edge sub-region 2352c can be located on both sides of the groove bottom surface 2352 respectively, and are arranged parallel to the X direction or the long side of the groove 235; the edge sub-region 2352b and the edge sub-region 2352d can be located on the groove bottom surface respectively. 2352 and are arranged parallel to the Z direction or the short side of the groove 235 .
  • the strain gauge 2341 is disposed in the center of the edge sub-region 2352a, which may be located between the groove wall 2353 and the projection area of the stress concentration layer 232 on the groove bottom surface 2352.
  • z 1 may be the spacing between the strain gauge 2341 and the groove wall 2353 , or z 1 may be the distance in the Z direction between the strain gauge 2341 and the groove wall 2353 .
  • the strain gauge 2342 is disposed in the center of the edge sub-region 2352b, and the edge sub-region 2352b may be located on the groove wall. 2354 and the stress concentration layer 232 between the projected area of the groove bottom surface 2352. x2 may be the spacing between the strain gauge 2342 and the groove wall 2354, or x2 may be the distance in the X direction between the strain gauge 2342 and the groove wall 2354.
  • the strain gauge 2343 is disposed in the center of the edge sub-region 2352c, which may be located between the groove wall 2355 and the projection area of the stress concentration layer 232 on the groove bottom surface 2352.
  • Z 3 may be the spacing between the strain gauge 2343 and the groove wall 2355 , or z 3 may be the distance in the Z direction between the strain gauge 2343 and the groove wall 2355 .
  • the strain gauge 2344 is disposed in the center of the edge sub-region 2352d, which may be located between the groove wall 2356 and the projection area of the stress concentration layer 232 on the groove bottom surface 2352.
  • X 4 may be the spacing between the strain gauge 2344 and the groove wall 2356 , or x 4 may be the distance in the X direction between the strain gauge 2344 and the groove wall 2356 .
  • a 1 *z 1 can be used as the expansion detection parameter of the strain gauge 2341
  • a 2 *x 2 is used as the expansion detection parameter of the strain gauge 2342
  • a 3 *z 3 is used as the expansion detection parameter of the strain gauge 2343
  • a 4 *x 4 is used as the expansion detection parameter of the strain gauge 2344.
  • the expansion detection parameters may be calibrated based on the force F0 and the signals output by strain gauges 2341, 2342, 2343, and 2344:
  • a 1 *z 1 2*S 1 (F 0 ,P 0 )/F 0 ;
  • a 2 *x 2 2*S 2 (F 0 ,P 0 )/F 0 ;
  • a 3 *z 3 2*S 3 (F 0 ,P 0 )/F 0 ;
  • a 4 *x 4 2*S 4 (F 0 ,P 0 )/F 0 .
  • the signals output by the strain gauge 2341, the strain gauge 2342, the strain gauge 2343 and the strain gauge 2344 can be obtained, which are respectively S 1 (F,P), S 2 (F,P ), S 3 (F,P) and S 4 (F,P).
  • F represents the battery expansion force to be detected
  • P represents the acting position of the battery expansion force F at the expansion detection component 230 , that is, the equivalent pressure action center.
  • the coordinates of P can be (Px, Pz), Px can refer to the coordinates of P in the X direction, and Pz can refer to the coordinates of P in the Z direction.
  • S 1 (F,P) F*A 1 *z 1 *(lz/2-Pz)/lz
  • S 2 (F,P) F*A 2 *x 2 *(lx/2-Px)/lx
  • S 3 (F,P) F*A 3 *z 3 *(lz/2-Pz)/lz
  • S 4 (F, P) F*A 4 *x 4 *(lx/2-Px)/lx.
  • FIG. 16A and 16B show experimental results of a battery module 200 provided by embodiments of the present application. Among them, FIG. 16A shows the monitoring results of the temperature and voltage of the battery module 200 , and FIG. 16B shows the monitoring results of the battery expansion force of the battery module 200 .
  • the temperature of the battery module 200 can be relatively stable, and the voltage of the battery module 200 can rise steadily.
  • the temperature of the battery module 200 still remains relatively stable, and the voltage of the battery module 200 still maintains a steadily rising state. That is to say, In terms of voltage and temperature, the performance of the battery module 200 within 10 to 30 minutes before failure is slightly different from the performance during normal operation. However, when the battery module 200 fails, the voltage and temperature of the battery module 200 change drastically. Therefore, it is impossible to predict whether the battery module 200 is about to fail based on the voltage and temperature.
  • the battery expansion force of the battery module 200 when the battery module 200 is operating normally, the battery expansion force of the battery module 200 is relatively small, and the battery expansion force of the battery module 200 may increase slightly.
  • the battery expansion force of the battery module 200 In the 30 minutes before the battery module 200 fails, the battery expansion force of the battery module 200 can be maintained in a relatively moderate range, and the battery expansion force of the battery module 200 can increase slightly. That is to say, in terms of battery expansion force, the performance of the battery module 200 in the 30 minutes before failure is slightly different from the performance when the battery is working normally.
  • the battery expansion force of the battery module 200 In the 10 minutes before the battery module 200 fails, the battery expansion force of the battery module 200 can increase suddenly, and the battery expansion force of the battery module 200 can increase to several times that of the normal state. That is to say, in terms of battery expansion force, the performance of the battery module 200 within 10 minutes before failure is significantly different from the performance during normal operation. Therefore, whether the battery module 200 is about to fail can be predicted based on the battery expansion force.
  • the electrical device 100 can monitor the battery expansion force of the battery module 200 in real time. In other embodiments, the electrical device 100 can monitor the battery expansion force of the battery module 200 under the following conditions: charging state, driving state, and parking state. If the rising speed of the battery expansion force and the specific value of the battery expansion force monitored by the electrical device 100 are within the normal range, it can be determined that the health status of the battery 210 is relatively good. Under different conditions, the normal behavior of battery expansion force can be slightly different. When an abnormality in the battery expansion force is detected, the battery 210 health management operation can be performed.
  • the electrical device 100 when it is detected that the rising slope of the battery expansion force is greater than the preset slope, it may mean that the battery expansion force of the battery module 200 rises abnormally and the battery module 200 fails within a short period of time (for example, 10 minutes). The possibility is relatively high.
  • the electrical device 100 can cut off the access of the battery module 200 to stop the battery module 200 from working.
  • the electrical device 100 can issue a warning to the user, for example, prompting the user that the battery 210 is out of control; or prompt the user to take first aid measures, such as emergency parking, calling the police for help, cooling, power outage, and fire extinguishing. .
  • the electrical device 100 can cut off the access of the battery module 200 to stop the battery module 200 from working.
  • the electrical device 100 can issue a warning to the user, for example, prompting the user that the battery 210 is out of control; or prompt the user to take first aid measures, such as emergency parking, calling the police for help, cooling, power outage, and fire extinguishing. , actively perform battery pressure release to prevent explosion, and discard the battery module 200 or battery pack 130 .
  • the preset battery expansion force 1 can be the preset battery expansion force 2 (several times)
  • the preset battery expansion force 1 can be the preset battery expansion force 2 (several times)
  • the power-consuming device 100 can reduce the power usage of the battery module 200, and the power-consuming device 100 can limit the output current and working time of the battery module 200.
  • the power-consuming device 100 may cool down the battery module 200 .
  • the power-consuming device 100 can prompt the user with battery risks and maintenance suggestions.
  • FIG. 17A is a schematic structural diagram of a battery module 200 provided by an embodiment of the present application.
  • FIG. 17B is an exploded view of the battery module 200 shown in FIG. 17A.
  • the battery module 200 may include multiple A battery 210, and oppositely arranged end plates 221 and 222.
  • the plurality of batteries 210 , the end plates 221 and the end plates 222 are arranged along the stacking direction Y, and the plurality of batteries 210 are sandwiched between the end plates 221 and 222 .
  • the battery module 200 shown in FIGS. 17A and 17B also includes an expansion detection component 230 with a different structure.
  • FIG. 18A is a schematic structural diagram of another battery module 200 provided by an embodiment of the present application.
  • FIG. 18B is an exploded view of the battery module 200 shown in FIG. 18A.
  • the battery 210 may include two expansion detection assemblies 230 , one expansion detection assembly 230 a may be located between the battery 210 a and the end plate 221 , and the other expansion detection assembly 230 b may be located between the battery 210 a and the end plate 221 .
  • the battery 210a may be the battery 210 closest to the end plate 221 among the plurality of batteries 210, and the battery 210b may be the battery 210 closest to the end plate 222 among the plurality of batteries 210.
  • the expansion detection component 230 may also be located between two adjacent batteries 210 .
  • the expansion detection assembly 230 shown in FIGS. 17A, 17B, 18A and 18B may refer to the embodiment shown in FIGS. 19A to 19C.
  • 19A to 19C show schematic structural diagrams of three expansion detection assemblies 230 provided by embodiments of the present application.
  • the expansion detection component 230 may include a deformation layer 233 and a strain gauge 234.
  • the deformation layer 233 may include an end surface 237 and an end surface 236 . 17A or 18A, the end surface 237 may be in contact with the battery 210a, and the end surface 236 may be disposed close to or facing the end plate 221.
  • the expansion detection component 230 may be sandwiched between the end plate 221 and the battery 210a, and the area of the end surface 236 located outside the groove opening 2351 may be in contact with the end plate 221.
  • battery 210 When battery 210 expands, battery 210 may exert a battery expansion force on end surface 237 .
  • End surface 236 may be provided with grooves 235 .
  • the thickness of the deformation layer 233 within the groove 235 (ie, the size along the stacking direction Y of the plurality of batteries 210) may be relatively small, and the thickness of the deformation layer 233 outside the groove 235 may be relatively large. Therefore, under the action of the battery expansion force, the groove bottom surface 2352 of the deformation layer 233 can be deformed relatively easily.
  • the strain gauge 234 may be disposed on the deformation layer 233 .
  • the strain gauge 234 may be used to detect the deformation amount of the groove bottom surface 2352 of the deformation layer 233 .
  • the strain gauge 234 may be disposed on the groove bottom surface 2352 of the deformation layer 233 .
  • the strain gauge 234 may be disposed on the end surface 237 of the deformation layer 233 , and part or all of the strain gauge 234 is located in a region of the end surface 237 opposite to the groove bottom surface 2352 . That is, the strain gauge 234 may be disposed between the deformation layer 233 and the battery 210a. Some or all of the strain gauges 234 may be located within the projected area of the groove bottom surface 2352 on the end surface 237 .
  • the projected area of the deformation layer 233 when viewed along the stacking direction Y of the plurality of batteries 210 , the projected area of the deformation layer 233 may completely coincide or substantially coincide with the projected area of the batteries 210 . If the projection area of the deformation layer 233 is located within the projection area of the battery 210, and the area difference between the projection area of the deformation layer 233 and the projection area of the battery 210 is large, then a part of the battery 210 may be in contact with the deformation layer 233, and the remaining part may be located in the deformation area. Outside layer 233.
  • the area of the battery 210 that is in contact with the deformation layer 233 can be blocked by the deformation layer 233, thereby constraining the expansion of the battery 210 to a certain extent; while the area of the battery 210 outside the deformation layer 233 cannot be affected by the deformation layer. 233, which may cause local abnormal expansion of the battery 210. It is relatively difficult to restore the local abnormal expansion of the battery 210 to normal, and it is relatively easy to cause safety accidents.
  • the expansion detection component 230 may be in a detection state.
  • the overall expansion of one or more batteries 210 is relatively large. Since the distance between the end plate 221 and the end plate 222 of the battery module 200 is relatively fixed, the position of the end surface 236 of the deformation layer 233 close to the end plate 221 in the battery module 200 can be relatively fixed, or the position of the end surface 236 of the deformation layer 233 close to the end plate 221 can be relatively fixed.
  • the end surface 236 of the plate 221 is in the stacking direction of the plurality of batteries 210 The displacement on Y is relatively small or even negligible.
  • the end surface 237 of the deformation layer 233 can withstand the battery expansion force, and the groove bottom surface 2352 of the deformation layer 233 tends to protrude toward the end plate 221 . That is to say, the groove bottom surface 2352 of the deformation layer 233 may be stretched, bent, warped, etc. deformed.
  • the expanded shape of the battery 210a in contact with the end surface 237 of the deformation layer 233 can match the deformation of the groove bottom surface 2352 of the deformation layer 233.
  • expansion information of one or more batteries 210 can be determined.
  • the battery expansion force of the battery 210 fluctuates in the range of approximately 0 to 20 kN.
  • the size of the end surface 237 of the deformation layer 233 may be 148mm*102.5mm. That is to say, viewed along the stacking direction Y of the plurality of batteries 210, the size of the projected area of the deformation layer 233 may be 148mm*102.5mm.
  • the thickness of the deformation layer 233 outside the groove 235 may be 5 mm.
  • the thickness of the deformation layer 233 in the groove 235 may be 4 mm. That is, the depth of the groove 235 may be 1 mm.
  • the size of the groove opening 2351 may be 128mm*82.5mm. In another embodiment, the size of the groove opening 2351 may be 138mm*92.5mm.
  • the thickness of strain gauge 234 may be less than the depth of groove 235 . Thus, the total thickness of the expansion detection component 230 may not exceed 5 mm.
  • the cross section of the groove 235 perpendicular to the stacking direction Y of the plurality of batteries 210 may be rectangular. In other embodiments, the cross section of the groove 235 perpendicular to the stacking direction Y of the plurality of batteries 210 may have other shapes. In the embodiment shown in FIG. 19B , the cross section of the groove 235 perpendicular to the stacking direction Y of the plurality of batteries 210 may be circular. In the embodiment shown in FIG. 19C , the cross section of the groove 235 perpendicular to the stacking direction Y of the plurality of batteries 210 may be elliptical. The cross-sectional shape of the groove 235 may not be limited to the embodiments provided in this application.
  • the ratio of the projected area of the groove bottom surface 2352 to the projected area of the battery 210 is relatively smaller.
  • the end face 237 may include a middle deformation region and an edge deformation region. Viewed along the stacking direction Y of the plurality of batteries 210 , the projection area of the middle deformation area may coincide with the projection area of the groove bottom surface 2352 , and the edge deformation area may not intersect with the projection area of the groove bottom surface 2352 .
  • the edge deformation area may surround the periphery of the projected area of the groove bottom surface 2352.
  • the middle deformation area is the main area that reflects the battery expansion force.
  • the detection range of the expansion detection component 230 may also be related to the depth of the groove 235 of the deformation layer 233 and the total thickness of the deformation layer 233 .
  • the detection range of the strain gauge 234 may be adapted to the deformation amount of the groove bottom surface 2352 of the deformation layer 233 .
  • two expansion detection assemblies 230 with different structures may be configured in the battery module 200, and the two expansion detection assemblies 230 may be used for different expansion force ranges.
  • Figure 20 shows several possible positions of strain gauge 234 within groove 235.
  • the specific position of the strain gauge 234 on the end surface 237 of the deformation layer 233 may refer to the embodiment in which the strain gauge 234 is disposed in the groove 235 .
  • Figures 20A, 20D, and 20G illustrate several possible positions of strain gauge 234 within groove 235 of rectangular cross-section.
  • Figures 20B, 20E, and 20H illustrate several possible positions of the strain gauge 234 within the groove 235 of circular cross-section.
  • Figures 20C, 20F, and 20I illustrate several possible positions of the strain gauge 234 within the groove 235 of elliptical cross-section.
  • the strain gauge 234 may be disposed close to the groove wall of the groove 235.
  • the deformation amount of the area of the groove bottom surface 2352 close to the groove wall may be relatively small.
  • the strain gauge 234 may be used to detect a relatively large battery expansion force.
  • Strain gauge 234 may be disposed on the axis of symmetry of groove 235 . The strain gauge 234 can be used to output the battery expansion force in the direction of the symmetry axis, which is beneficial to obtaining expansion information in the direction of the symmetry axis.
  • the strain gauge 234 there may be a distance a between the strain gauge 234 and the groove wall of the groove 235, and there may be a distance b between the strain gauge 234 and the center of the groove bottom surface 2352.
  • the distance a and the distance b may be the same or approximately the same or the difference may be relatively small.
  • the strain gauge 234 is positioned relatively close to the center of the groove bottom surface 2352, so a relatively large amount of deformation can occur in the area where the strain gauge 234 is located.
  • the strain gauge 234 can be used to detect a relatively small battery expansion force, and to relatively sensitively detect changes in the battery expansion force within an effective range.
  • the strain gauge 234 may be disposed on the axis of symmetry of the groove 235 .
  • the strain gauge 234 can be used to output the battery expansion force in the direction of the symmetry axis, which is beneficial to obtaining expansion information in the direction of the symmetry axis.
  • expansion detection assembly 230 may include a greater or lesser number of strain gauges 234.
  • the expansion detection component 230 may include only one strain gauge 234.
  • the strain gauge 234 may be disposed in the center of the groove bottom surface 2352. The center of the groove bottom surface 2352 usually corresponds to the position where the battery 210 expands the most, which is helpful for quickly detecting abnormal expansion of the battery 210 .
  • Embodiments of the present application provide an expansion detection component, a battery module, a battery pack and an electrical device.
  • the expansion detection component By arranging the expansion detection component in the battery module, the expansion information of the battery module can be detected, which is conducive to accurate assessment of the status of the battery module and prediction of battery module failure.
  • the expansion detection component is deformed under the action of battery expansion force. The deformation of the expansion detection component is detected through the strain gauge, and the battery expansion force endured by the expansion detection component is obtained.

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Abstract

本申请实施例提供了一种电池模组、电池包和用电装置。电池模组或电池包包括：电池和膨胀检测组件，膨胀检测组件用于检测电池膨胀力。膨胀检测组件包括形变层和应变计。形变层包括与电池相对的凹槽，凹槽底面可以在电池膨胀的作用下变形。应变计设置于形变层，用于检测所述凹槽底面的应变。本申请实施例提供方案有利于相对准确检测到电池膨胀的信息，以便于相对准确地预判电池是否即将失效。

Description

电池模组、电池包和用电装置
本申请要求于2022年04月29日提交中国专利局、申请号为202210466136.6、发明名称为“电池模组、电池包和用电装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请实施例涉及电池领域，并且更具体地，涉及电池模组、电池包和用电装置。
背景技术
电池的电流、电压和温度等信息可以反映电池是否发生失效。然而，电池的电流、电压和温度等信息较难对电池失效产生预警。当电池的电流、电压和温度等信息出现异常时，电池往往已经失效，此时电池可能已经导致相对严重的安全隐患，如燃烧、爆炸等。因此，仅根据电池的电流、电压和温度等信息，无法提前预警电池失效，无法预先调整电池充放电状态，进而无法及时避免电池安全事故。
电池在失效前，电池内可能发生不稳定的化学反应，导致电池明显膨胀。因此电池膨胀的信息可以用于预判电池是否即将失效。然而在正常使用电池的过程中，电池也可能发生膨胀。并且，电池的膨胀情况可以相对复杂，例如电池可以局部膨胀，也可以整体膨胀。如何准确检测到电池膨胀的信息，以预判电池是否即将失效，是需要解决的技术问题。
发明内容
本申请实施例提供一种电池模组、电池包和用电装置，目的是相对准确检测到电池膨胀的信息，以便于相对准确地预判电池是否即将失效。
第一方面，提供了一种电池模组，包括：
电池和膨胀检测组件，所述膨胀检测组件包括：
形变层，所述形变层包括第一端面和第二端面，所述第一端面靠近所述电池设置，所述第二端面远离所述电池设置，所述形变层的第二端面设置有凹槽；
应变计，所述应变计设置于所述形变层，所述应变计用于检测所述凹槽的凹槽底面的应变。
通过在电池模组设置膨胀检测组件，膨胀检测组件在电池膨胀力的作用下发生变形。应变计可以检测到膨胀检测组件的变形情况，进而获取膨胀检测组件承受的电池膨胀力。因此，电池模组的膨胀信息可以被检测到，进而有利于准确评估电池模组的状态，有利于针对电池模组失效进行预判。
在电池膨胀力相同时，电池膨胀的具体形式可以不同。例如，电池的膨胀中心位于电池的中心或重心。又如，电池的膨胀中心偏离电池的中心或重心。膨胀检测组件可以响应电池膨胀力的作用而产生形变，使得在膨胀量复杂多样的场景下，膨胀检测组件可以兼顾多种电池膨胀情况。也就是说，电池膨胀力的检测不受限于具体的电池膨胀量。
结合第一方面，在第一方面的某些实现方式中，所述膨胀检测组件还包括承压层和应力集中层，所述应力集中层位于所述承压层和所述形变层之间，所述承压层与所述电池相邻，所述凹槽底面可在所述应力集中层的作用下形变。
应力集中层可以向形变层施加相对较大的压强，使形变层的形变量相对明显。当多个电池在承压层上作用大小不同的电池膨胀力时，形变层的形变量可以区分相对明显，有利于提高电池的膨胀信息的检测精度。
结合第一方面，在第一方面的某些实现方式中，所述应变计设置于所述凹槽底面上，且位于所述凹槽底面的与所述应力集中层相对的区域外。
形变层和应力集中层之间的间隔距离可能相对较窄。在形变层和应力集中层一体成型的情况下，在形变层的远离应力集中层的一侧设置应变计可以相对便利。
结合第一方面，在第一方面的某些实现方式中，所述凹槽底面的形状为矩形，所述凹槽底面包括边缘子区域，所述边缘子区域位于所述凹槽的槽壁和所述凹槽底面的与所述应力集中层相对的区域之间，所述边缘子区域相对于所述凹槽底面的长边或短边平行设置；
所述应变计设置于所述边缘子区域的中心，或者，所述应变计设置于所述边缘子区域的端部。
当应变计设置于边缘子区域的中心，应变计可以主要用于检测在对称轴上或在某个方向上的应变，进而反映电池膨胀力在对称轴上或在某个方向上的分力，进而有利于获取在对称轴上或在某个方向上的膨胀信息。
当应变计设置于边缘子区域的端部，边缘子区域的端部的应变可以具有多个方向的分量，有利于综合反映总电池膨胀力。
应变计还可以设置于边缘子区域的中心和边缘子区域的端部之间。边缘子区域的端部可能会存在局部特殊形变。应变计与边缘子区域的端部之间存在一定距离，有利于降低应变计检测到局部特殊形变的可能性，减少局部特殊形变对总体膨胀信息的影响。
由于边缘子区域的中心位置和边缘子区域的中心位置承受的应力相对较小，因此边缘子区域的中心位置和边缘子区域的中心位置更容易发生弹性恢复。由此有利于实现膨胀检测组件循环多次工作。
结合第一方面，在第一方面的某些实现方式中，所述第一端面包括与所述凹槽底面相对设置的形变区域，所述应变计设置于所述形变区域，且位于所述形变区域的与所述应力集中层相对的区域外。
应变计可以隐藏于形变层和应力集中层之间的缝隙中，有利于降低应变计脱落的可能性。
结合第一方面，在第一方面的某些实现方式中，所述应变计设置于所述边缘部分的对称轴上，或者，所述应变计设置于所述边缘部分的角上。
当应变计设置于边缘部分的对称轴上，应变计可以主要用于检测在对称轴所在方向上的应变，进而反映电池膨胀力在对称轴所在方向上的分力，进而有利于获取在对称轴所在方向上的膨胀信息。
当应变计设置于边缘部分的角上，边缘部分的角上的应变可以具有多个方向的分量，有利于综合反映总电池膨胀力。
结合第一方面，在第一方面的某些实现方式中，所述承压层的刚度大于所述凹槽底面的刚度。
承压层的刚度相对较大，有利于减小承压层的变形量，使电池膨胀力尽可能通过形变层的凹槽底面的变形量体现。
结合第一方面，在第一方面的某些实现方式中，所述应力集中层的刚度大于所述凹槽底面的刚度。
应力集中层的刚度相对较大，有利于减小应力集中层的变形量，使电池膨胀力尽可能通过形变层的凹槽底面的变形量体现。
结合第一方面，在第一方面的某些实现方式中，所述承压层、所述应力集中层和所述形变层一体成型。
通过一体成型，有利于使承压层、应力集中层和形变层之间定位更加准确，还有利于减少组装承压层、应力集中层和形变层所需的连接件，减少膨胀检测组件在电池模组内的占用空间。
结合第一方面，在第一方面的某些实现方式中，所述第一端面与所述电池相邻。
形变层与电池模组直接接触，有利于相对动态地获取电池的具体膨胀量。
结合第一方面，在第一方面的某些实现方式中，所述应变计设置于所述凹槽底面；或者，所述第一端面包括与所述凹槽底面相对设置的形变区域，所述应变计设置于所述形变区域内。
应变计可以隐藏于凹槽内，有利于减少与应变计在电池模组内的占用空间。
应变计可以夹设于形变层和电池之间，有利于直接感知电池的具体膨胀量。
结合第一方面，在第一方面的某些实现方式中，所述形变层的材料为以下中的任一项：合金钢、铝合金和钛合金。
形变层的刚度可以相对较高，有利于形变层在电池膨胀力的作用下发生弹性变形，降低形变层屈服的可能性，进而有利于使膨胀检测组件可以循环多次工作。
结合第一方面，在第一方面的某些实现方式中，所述凹槽底面的形状为以下中的任一项：矩形、圆形和椭圆形。
通过灵活设置凹槽底面的形状，有利于灵活调整凹槽底面与电池的面积比。凹槽底面与电池的面积比相对较大，则形变层能够捕捉到的电池膨胀信息相对较多。
结合第一方面，在第一方面的某些实现方式中，所述电池模组还包括端板，所述膨胀检测组件夹设于所述端板和所述电池之间。
膨胀检测组件紧贴端板设置，有利于捕捉电池模组内多个电池的膨胀信息。
第二方面，提供了一种电池包，包括如上述第一方面中的任意一种实现方式中所述的电池模组。
结合第二方面，在第二方面的某些实现方式中，所述电池包还包括电池管理系统BMS控制模块，所述BMS控制模块用于获取所述应变计输出的信号。
BMS控制模块可以灵活获取电池的膨胀信息，并灵活调整电池的工作状态，使电池可以处于相对健康的状态。BMS控制模块还可以根据电池的膨胀信息，预判电池是否即将失效，并在失效前采取急救措施。
第三方面，提供了一种电池包，包括：
电池和膨胀检测组件，所述膨胀检测组件包括：
形变层，所述形变层包括第一端面和第二端面，所述第一端面靠近所述电池设置，所述第二端面远离所述电池设置，所述形变层的第二端面设置有与所述电池相对的凹槽；
应变计，所述应变计设置于所述形变层，所述应变计用于检测所述凹槽的凹槽底面的应变。
结合第三方面，在第三方面的某些实现方式中，所述电池包还包括电池管理系统BMS控制模块，所述BMS控制模块用于获取所述应变计输出的信号。
第四方面，提供了一种用电装置，包括如上述第二方面至第三方面中的任意一种实现方式中所述的电池包。
第五方面，提供了一种获取膨胀信息的方法，包括：
获取所述应变计输出的第一信号；
根据所述第一信号和膨胀检测参数，获取膨胀信息，所述膨胀检测参数用于指示所述第一信号和电池膨胀力的关系，所述膨胀信息用于指示所述电池膨胀力。
上述第四方面中的任意一种实现方式中所述的用电装置可以实现电池膨胀力和应变计的电压差大体呈线性关系，因此可以相对准确地估计电池膨胀力。
上述方法可以应用于如上述第四方面中的任意一种实现方式中所述的用电装置。
结合第五方面，在第五方面的某些实现方式中，所述膨胀检测参数包括以下中的至少一项：
所述应变计的电压差-所述电池膨胀力的斜率；
所述应变计的多个电压差和多个电池膨胀力，所述多个电压差和所述多个电池膨胀力一一对应；
所述应变计检测到的应变量-所述电池膨胀力的斜率；
所述应变计检测到的多个应变量和多个电池膨胀力，所述多个应变量和所述多个电池膨胀力一一对应；
所述应变计在所述膨胀检测组件上的位置信息；
所述应变计的应变计系数；
与所述膨胀检测组件的中心位置相关的参数。
膨胀检测参数越丰富，获取到的电池膨胀信息越丰富。例如可以预估电池膨胀力、电池膨胀力的作用位置等、调整检测量程等。
结合第五方面，在第五方面的某些实现方式中，所述方法还包括：
根据所述第一信号，确定电池膨胀力的作用位置。
当电池膨胀力的作用位置偏离明显时，可能意味着电池膨胀异常。此时调整电池的工作状态，有利于降低电池发生安全事故的可能性。
结合第五方面，在第五方面的某些实现方式中，所述方法还包括：
在校准模式下，获取所述应变计输出的第二信号；
根据施加于所述膨胀检测组件的作用力和所述第二信号，校准所述膨胀检测参数。
根据应变计输出的信号，可以对膨胀检测组件进行校准，有利于后续相对准确地获取电池的膨胀信息。
结合第五方面，在第五方面的某些实现方式中，所述方法还包括：
当所述电池膨胀力大于预设电池膨胀力时，或者，当所述电池膨胀力的上升斜率大于预设斜率时，
执行以下中的一个或多个操作：
降低电池的使用功率；
降低电池的温度；
对电池进行压力释放；
发出警告；
紧急停车。
在电池膨胀力出现异常时，执行针对电池的操作，有利于降低电池发生安全风险的可能性。
第六方面，提供了一种膨胀检测组件，包括：
形变层，所述形变层包括第一端面和第二端面，所述第一端面用于靠近电池设置，所述第二端面用于远离所述电池设置，所述形变层的第二端面设置有凹槽，所述凹槽用于与所述电池相对；
应变计，所述应变计设置于所述形变层，所述应变计用于检测所述凹槽的凹槽底面的应变。
结合第六方面，在第六方面的某些实现方式中，所述膨胀检测组件还包括承压层和应力集中层，所述应力集中层位于所述承压层和所述形变层之间，所述承压层用于与所述电池接触，所述第一端面包括与所述凹槽底面相对设置的形变区域，所述形变区域包括中间部分和边缘部分，所述中间部分与所述应力集中层相连，所述边缘部分围绕于所述应力集中层的外周。
结合第六方面，在第六方面的某些实现方式中，部分或全部所述应变计设置于所述凹槽底面上，且位于所述凹槽底面的与所述应力集中层相对的区域外。
结合第六方面，在第六方面的某些实现方式中，所述凹槽底面的形状为矩形，所述凹槽底面包括边缘子区域，所述边缘子区域位于所述凹槽的槽壁和所述凹槽底面的与所述应力集中层相对的区域之间，所述边缘子区域相对于所述凹槽底面的长边或短边平行设置；
所述应变计设置于所述边缘子区域的中心，或者，所述应变计设置于所述边缘子区域的端部。
结合第六方面，在第六方面的某些实现方式中，部分或全部所述应变计设置于所述边缘部分。
结合第六方面，在第六方面的某些实现方式中，所述应变计设置于所述边缘部分的对称轴上，或者，所述应变计设置于所述边缘部分的角上。
结合第六方面，在第六方面的某些实现方式中，所述承压层的刚度大于所述凹槽底面的刚度。
结合第六方面，在第六方面的某些实现方式中，所述应力集中层的刚度大于所述凹槽底面的刚度。
结合第六方面，在第六方面的某些实现方式中，所述承压层、所述应力集中层和所 述形变层一体成型。
结合第六方面，在第六方面的某些实现方式中，所述第一端面用于与所述电池接触。
结合第六方面，在第六方面的某些实现方式中，所述应变计设置于所述凹槽底面；或者，所述第一端面包括与所述凹槽底面相对设置的形变区域，所述应变计设置于所述形变区域内。
结合第六方面，在第六方面的某些实现方式中，所述形变层的材料为以下中的任一项：合金钢、铝合金和钛合金。
结合第六方面，在第六方面的某些实现方式中，所述凹槽底面的形状为以下中的任一项：矩形、圆形和椭圆形。
附图说明
图1是本申请实施例提供的一种用电装置的示意性结构图。
图2是本申请实施例提供的一种电池包的示意性结构图。
图3A是本申请实施例提供的一种电池模组的示意性结构图。
图3B是本申请实施例提供的一种电池模组的爆炸图。
图4A是本申请实施例提供的另一种电池模组的示意性结构图。
图4B是本申请实施例提供的另一种电池模组的爆炸图。
图5A是本申请实施例提供的一种膨胀检测组件的示意性结构图。
图5B是本申请实施例提供的一种膨胀检测组件的爆炸图。
图6A是本申请实施例提供的一种应变计的示意性结构图。
图6B是本申请实施例提供的另一种应变计的示意性结构图。
图6C是本申请实施例提供的又一种应变计的示意性结构图。
图7A是图5A所示的膨胀检测组件处于初始状态的示意性结构图。
图7B是图5A所示的膨胀检测组件处于检测状态的示意性结构图。
图8A是本申请实施例提供的另一种膨胀检测组件的示意性结构图。
图8B是本申请实施例提供的另一种膨胀检测组件的爆炸图。
图9A是本申请实施例提供的又一种膨胀检测组件的示意性结构图。
图9B是本申请实施例提供的又一种膨胀检测组件的爆炸图。
图10A至图10D是图5A所示的膨胀检测组件的模拟结果图。
图11A至图11D示出了应变计在膨胀检测组件上的设置位置。
图12是图5A所示的膨胀检测组件的实验结果图。
图13是本申请实施例提供的一种膨胀检测组件的示意性结构图。
图14是本申请实施例提供的一种获取膨胀信息的示意性流程图。
图15是本申请实施例提供的一种获取膨胀作用中心的原理图。
图16A和图16B是本申请实施例提供的一种膨胀检测组件的实验结果图。
图17A是本申请实施例提供的一种电池模组的示意性结构图。
图17B是本申请实施例提供的一种电池模组的爆炸图。
图18A是本申请实施例提供的另一种电池模组的示意性结构图。
图18B是本申请实施例提供的另一种电池模组的爆炸图。
图19A是本申请实施例提供的一种膨胀检测组件的示意性结构图。
图19B是本申请实施例提供的另一种膨胀检测组件的示意性结构图。
图19C是本申请实施例提供的又一种膨胀检测组件的示意性结构图。
图20A至图20I示出了应变计在膨胀检测组件上的设置位置。
具体实施方式
下面将结合附图，对本申请实施例中的技术方案进行描述。
图1是本申请实施例提供的一种用电装置100的示意性结构图。用电装置100例如可以是车辆、轮船等可移动装置。以车辆为例，车辆可以为电动车/电动汽车，如纯电动汽车、混合动力汽车、增程式电动汽车、燃料电池车辆、插电式混合动力汽车、新能源汽车(new energy vehicle)等。电动车可以包括两轮、三轮或者四轮电动车。本申请实施例应用在用电装置100上的方案还可以应用于其他设备，例如终端消费产品或3C电子产品(计算机类(computer)、通信类(communication)、消费类(consumer)电子产品)，如手机、移动电源、平板电脑、电子阅读器、笔记本电脑、数码相机、可穿戴设备、耳机等。图1所示实施例以用电装置100是车辆为例进行说明。
用电装置100可以包括前轮121、后轮122以及连接在前轮121和后轮122之间的车辆本体。车辆本体上可以安装有若干部件，这些部件可以驱动前轮121和/或后轮122转动，从而移动用电装置100。例如，车辆本体上可以安装有传动部件、电机和电池包130。电池包130可以向电机输入电能，从而电机可以转动，并通过传动部件带动前轮121和/或后轮122转动。
图2是本申请实施例提供的一种电池包130的示意性结构图。
电池包130可以包括电池箱131，电池箱131内可以设置有多个电池模组200。
电池箱131可以包括电池箱主体和盖板。盖板例如可以覆盖并扣合于电池箱主体的开口，以形成电池箱131的封闭腔室。多个电池模组200相互并联或串联或混联组合后置于该封闭腔室内。
在第一种实施方式中，多个电池可以组装形成电池模组(module)200，然后多个电池模组200设置于电池包130的电池箱131中。在该实施方式中，相邻的两个电池模组200之间可以设置有横梁等辅助结构件，以提高电池模组200在电池箱131中的安装稳定性。
在第二种实施方式中，多个电池可以相互堆叠，并设置于电池包130的电池箱131中。也就是说，与第一种实施方式相比，去除了电池模组200这个中间状态。由此有利于可降低电池包130的质量并提高电池包130的能量密度。第二种实施方式可以是电池至电池包130(cell to pack，CTP)技术。
在第三种实施方式中，上述电池箱131可集成于电池包130所在的用电装置。也就是说，上述电池箱131可以与用电装置100中的结构件一体成型。例如，电池箱131可集成设置于用电装置100的底盘的局部区域。第三种实施方式可以是电池至底盘(cell to chassis，CTC)技术。
在一些实施例中，电池包130还可以包括汇流部件，汇流部件可以汇聚多个电池或多个电池模组200的正极电流，形成电池包130的正极电流；汇流部件还可以汇聚多个电池 或多个电池模组200的负极电流，形成电池包130的负极电流。汇流部件用于实现多个电池或多个电池模组200之间的电连接，例如并联或串联或混联。电池包130还可以通过导电机构，将多个电池或多个电池模组200的电能输出至电池包130以外。在一种可能的情况下，导电机构可以是汇流部件的一部分。
在一些实施例中，电池包130还可以包括电池管理系统(battery management system，BMS)控制模块和线缆等。BMS控制模块用于通过线缆控制多个电池或多个电池模组200的工作状态。例如BMS控制模块可以通过线缆监控电池模组200的电压、电流、功率或温度等。又如，当检测到某个电池模组200发生故障时，BMS控制模块可以断开故障电池模组200，有利于其他电池模组200可以正常工作。在一种可能的情况下，电池包130可以包括BMS控制模块132和多个BMS控制模块133。BMS控制模块132可以用于控制多个电池模组200的工作状态。多个BMS控制模块133可以与电池包130的多个电池模组200一一对应。每个电池模组200可以包括多个电池，BMS控制模块133可以用于控制对应的电池模组200的多个电池的工作状态。
在一些实施例中，电池包130还可以包括热管理部件。热管理部件可以用于将电池包130产生的热量排向电池包130外，以有利于电池包130在相对合适的温度下正常工作。热管理部件内可以具有冷却介质。冷却介质可以通过热管理部件流入电池包130、并流出电池包130，从而冷却介质可以带走电池包130产生的热量。在一些实施例中，冷却介质可以是空气，也可以是其他冷却介质，例如惰性气体，或者液体等，本申请实施例可以对此不作限定。
在其他可能的实施例中，上述实施例中的电池包130或电池模组200可以被称为电池，上述实施例中的电池可以被称为电池单体。下面以电池模组200为例，阐述本申请提供的实施例。
图3A是本申请实施例提供的一种电池模组200的示意性结构图。图3B是图3A所示的一种电池模组200的爆炸图。
电池模组200可以包括多个电池210。电池210用于将化学能转化为电能。在产生电能的过程中，电池210可以膨胀，还可以产生热量。
电池210可以包括电极组件、电解液和电池外壳。电极组件和电解液可以收容于电池外壳中。电极组件可以包括正极极片、负极极片、隔膜。正极极片、负极极片可以脱嵌金属离子(如锂离子)，以实现能量的存储和释放。正极极片、负极极片是电池210的主体储能部分，可以体现电池210的能量密度、循环性能及安全性能。在间隔设置的正极极片、负极极片之间可以填充有隔膜。隔膜可透过金属离子，但隔膜本身不导电，从而隔膜可以将正极极片、负极极片隔开，以防止正极极片、负极极片之间短路。电解液可以是金属离子在正极极片、负极极片之间的传输载体。
电池210可以是但不限于锂聚合物电池、锂离子电池、铅酸电池、镍镉电池、镍金属氢电池等充电电池。电池210的形状例如可以为条形或者板状。在一个实施例中，电池模组200中的多个电池210可以是同一型号的电池。图3A和图3B所示的多个电池210的数量可以是示意性的。电池模组200中电池210的数量可以多于2个，也可以少于2个，即电池模组200可以仅包括一个电池210。本申请对电池模组200中电池210的数量并不作具体限定。
多个电池210可以是堆叠设置。在一个实施例中，如图3B所示，相邻两个电池210的大面211(大面211可以指电池210的面积最大的表面)可以相向设置。也就是说，多个电池210可以通过电池210的大面211堆叠。电池210的大面211可以是电池210的堆叠面。多个电池210的堆叠方向(Y方向)可以相对于电池210的大面211垂直设置。电池210的侧面212(侧面212可以指电池210的面积中等的表面)或小面213(小面213可以指电池210的面积最小的表面)上可以设置电极端子。正极电极端子可以与电池210的正极极片导通。负极电极端子可以与电池210的负极极片导通。在其他实施例中，多个电池210可以通过电池210的侧面212或小面213堆叠。
电池210还可以包括相对设置的端板221和端板222。端板221和端板222能够对多个电池210起到固定和保护作用。在制作电池模组200时，可以首先通过端板221和端板222将多个电池210夹紧，然后将端板221和端板222固定。在一个实施例中，端板221、端板222和多个电池210可以通过安装带捆绑固定。
在一个实施例中，如图3B所示，端板221和端板222可以与电池模组200的大面211相对设置。也就是说，端板221和端板222可以沿多个电池210的堆叠方向Y设置于多个电池210的两侧。在使用电池模组200的过程中，电池210在大面211上具有相对较大的膨胀趋势。端板221和端板222可以具有相对较高的刚度，有利于吸收或抵抗电池210在大面211上的膨胀量，为电池模组200提供相对较强的约束力，从而可以降低电池模组200过度膨胀的可能性。
在其他实施例中，端板221和端板222可以与电池模组200的侧面212或小面213相对设置。
电池模组200还可以包括一个或多个膨胀检测组件230。膨胀检测组件230可以用于检测一个或多个电池210的膨胀信息。在一种可能的情况下，如图3A和图3B所示，电池210可以包括一个膨胀检测组件230，该膨胀检测组件230可以位于电池210a和端板221之间，该电池210a可以是多个电池210中最靠近端板221的电池210。
图4A是本申请实施例提供的另一种电池模组200的示意性结构图。图4B是图4A所示的一种电池模组200的爆炸图。在另一种可能的情况下，如图4A和图4B所示，电池模组200可以包括两个膨胀检测组件230，其中一个膨胀检测组件230a可以位于电池210a和端板221之间，另一个膨胀检测组件230b可以位于电池210b和端板222之间，电池210a可以是多个电池210中最靠近端板221的电池210，电池210b可以是多个电池210中最靠近端板222的电池210。
在又一种可能的情况下，膨胀检测组件230还可以位于相邻两个电池210之间。在一个实施例中，膨胀检测组件230可以相对靠近端板221或端板222设置。也就是说，膨胀检测组件230可以在多个电池210的堆叠方向Y上相对远离多个电池210的中心电池。中心电池可以指多个电池210中最中间的电池210。
图5A示出了本申请实施例提供的一种膨胀检测组件230的示意性结构图。将图5A所示膨胀检测组件230按照结构进行划分，可以得到膨胀检测组件230的多个部分，如图5B所示。
膨胀检测组件230可以包括承压层231、应力集中层232、形变层233和应变计234。结合图5A和图3A，或者结合图5A和图4A，承压层231可以与电池210相邻。也就是 说，承压层231与电池210可以是相邻设置的两个部件。当电池210膨胀时，电池210可以在承压层231上作用电池膨胀力。应力集中层232可以位于承压层231和形变层233之间。应力集中层232可以承受来自承压层231的电池膨胀力，并将该电池膨胀力传递至形变层233。
形变层233的远离应力集中层232的一侧可以设置有凹槽235，凹槽开口2351背离应力集中层232设置。在形变层233的远离应力集中层232的端面236上，位于凹槽开口2351以外的区域可以用于与电池210或端板221接触。形变层233在凹槽235内的厚度(即沿多个电池210的堆叠方向Y的尺寸)可以相对较小，形变层233在凹槽235外的厚度可以相对较大。因此应力集中层232的作用下，形变层233的凹槽底面2352可以相对容易变形。应变计234可以设置于形变层233。应变计234例如可以通过粘贴固定于形变层233。应变计234可以用于检测形变层233的凹槽底面2352的变形量。在一种可能的场景中，凹槽底面2352的变形可以为弹性变形。当电池膨胀力减小后，凹槽底面2352可以逐渐向初始状态恢复。
在一些实施例中，承压层231、应力集中层232和形变层233可以使用相同材料。在另一些实施例中，承压层231、应力集中层232和形变层233可以使用不同材料。承压层231、应力集中层232和形变层233中的任一个可以选用强度相对较高的材料，以使得承压层231、应力集中层232和应变层233可以具有相对较高的屈服强度。承压层231、应力集中层232和形变层233中的任一个可以选用合金钢(如钨钢、高速钢、碳素钢等)或铝合金或钛合金等高强度材料。在一种可能的情况下，形变层233的凹槽底面2352的刚度可以小于承压层231的刚度，且小于应力集中层232的刚度。
当承压层231、应力集中层232和形变层233为金属等导体材料时，为降低承压层231、应力集中层232和形变层233与电池210短路的可能性，承压层231、应力集中层232和形变层233的外周可以设置有绝缘材料。
在一些实施例中，沿多个电池210的堆叠方向Y观察，承压层231的投影区域可以与电池210的投影区域完全重合或基本重合。如果承压层231的投影区域位于电池210的投影区域内，且承压层231的投影区域与电池210的投影区域面积相差较大，则电池210的一部分可以与承压层231接触，剩余部分可能位于承压层231以外。当电池210膨胀时，电池210的与承压层231接触的区域可以受承压层231的阻挡，从而在一定程度上约束电池210的膨胀；而电池210的位于承压层231以外的区域无法受承压层231的阻挡，从而可能导致电池210局部异常膨胀。电池210局部异常膨胀相对难以恢复正常，且相对容易造成安全事故。
在一些实施例中，沿多个电池210的堆叠方向Y观察，应力集中层232的投影面积可以小于承压层231的投影面积。在一种可能的情况下，沿多个电池210的堆叠方向Y观察，应力集中层232的投影区域可以位于承压层231的投影区域内。在一个实施例中，沿多个电池210的堆叠方向Y观察，应力集中层232的中心可以与承压层231的中心对齐设置。
假设承压层231的投影面积为A1，应力集中层232的投影面积为A2。假设承压层231承受的电池膨胀力为F，则承压层231承受的压强P1≈F/A1。应力集中层232可以承受来自承压层231的电池膨胀力F，因此应力集中层232承受的压强P2≈F/A2。由于A2<A1， 因此P2>P1。由此，应力集中层232可以向形变层233施加相对较大的压强，使形变层233的形变量相对明显。当多个电池210在承压层231上作用大小不同的电池膨胀力时，形变层233的形变量可以区分相对明显，有利于提高电池210的膨胀信息的检测精度。如果，当多个电池210在承压层231上作用大小不同的电池膨胀力时，形变层233的形变量区分不够明显，则形变层233上形变计输出的信号区别较小，进而相对较难反映电池210的准确膨胀信息。
在第一种实施方式中，如图5A或图5B所示，应变计234可以设置于形变层233的凹槽底面2352，且部分或全部应变计234位于凹槽底面2352的与应力集中层232相对的区域以外。也就是说，沿多个电池210的堆叠方向Y观察，凹槽底面2352的投影区域可以包括凹槽底面中间区域和凹槽底面边缘区域，凹槽底面中间区域可以与应力集中层232的投影区域完全重合，凹槽底面边缘区域可以位于应力集中层232的投影区域以外。应变计234可以设置于形变层233的凹槽底面2352上，且部分或全部应变计234位于凹槽底面边缘区域。在一种可能的情况下，形变层233和应力集中层232之间的间隔距离可能相对较窄。在形变层233和应力集中层232一体成型的情况下，在形变层233的远离应力集中层232的一侧设置应变计234可以相对便利。
在第二种实施方式中，应变计234可以设置于形变层233的靠近应力集中层232的端面237，且部分或全部应变计234位于端面237的与应力集中层232相对的区域以外。端面237可以是形变层233的与电池210相邻的端面。在本申请中，端面237可以与电池210的堆叠面面对面设置。在一种可能的情况下，端面237可以与多个电池210的堆叠方向Y垂直设置。
在形变层233的靠近应力集中层232的端面237上，具有与凹槽底面2352相对设置的形变区域，该形变区域的中间部分与应力集中层232连接，该形变区域的边缘部分围绕于应力集中层232的外周。应变计234可以设置于形变层233和应力集中层232之间，部分或全部应变计234可以位于上述形变区域的边缘部分。
也就是说，沿多个电池210的堆叠方向Y观察，端面237上的形变区域的投影区域可以与凹槽底面2352的投影区域完全重合；沿多个电池210的堆叠方向Y观察，形变区域的投影区域包括中间投影区域和边缘投影区域；该中间投影区域是形变区域的中间部分的投影区域，该中间投影区域与应力集中层232的投影区域完全重合；该边缘投影区域是形变区域的边缘部分的投影区域，该边缘投影区域位于应力集中层232的投影区域以外。上述形变区域的中间区域可以与凹槽底面中间区域相对设置，上述形变区域的边缘区域可以与凹槽底面边缘区域相对设置。沿多个电池210的堆叠方向Y观察，应变计234的投影区域可以与该边缘投影区域部分重合。
在一些实施例中，膨胀检测组件230的承压层231、应力集中层232和形变层233可以通过组装得到。例如，承压层231、应力集中层232、形变层233可以通过以下中的一个或多个组装：粘贴、铆接、焊接和插接等。
在另一些实施例中，膨胀检测组件230的承压层231、应力集中层232和形变层233中的至少两个可以通过一体成型得到。例如，承压层231、应力集中层232和形变层233通过一体成型得到。又如，承压层231和应力集中层232通过一体成型得到，形变层233和应力集中层232通过组装得到。又如，形变层233和应力集中层232通过一体成型得 到，承压层231和应力集中层232通过组装得到。
图6A至图6C示出了本申请实施例提供的几种应变计234的示意性结构图。应理解，本申请阐述的应变计234可以不限于图6A至图6C所示的应变计234。
图6A示出的应变计234可以为单电阻应变计。单电阻应变计的检测原理是，当单电阻应变计拉伸后，单电阻应变计的长度可以发生变化，进而单电阻应变计的电阻可以发生变化。单电阻应变计的电阻可以反映单电阻应变计的长度变化情况。单电阻应变计例如可以用于检测沿单电阻应变计的长度方向的应变。
图6B示出的应变计234可以为平行栅全桥应变计234。平行栅全桥应变计可以包括应变栅234a、应变栅234b、应变栅234c和应变栅234d。应变栅234a、应变栅234b、应变栅234c和应变栅234d的长度方向可以相互平行。应变栅234a、应变栅234b、应变栅234c和应变栅234d检测应变的方向可以相互平行。应变栅234a、应变栅234b、应变栅234c和应变栅234d按照全桥模式电连接。也就是说，包含应变栅234a、应变栅234b、应变栅234c和应变栅234d的电路可以是全桥电路。假设应变的方向平行于应变栅234a的长度方向，应变栅234a和应变栅234b检测同一位置变形量，应变栅234c和应变栅234d检测同一位置变形量。则应变栅234a的电压差和应变栅234b的电压差均可以为V1，应变栅234c的电压差和应变栅234d的电压差均可以为V2，则应变计234的总电压差为2×(V1-V2)。平行栅全桥应变计234有利于减少温度、直流偏置等因素对检测结果的影响。
图6C示出的应变计234可以为垂直栅全桥应变计。垂直栅全桥应变计可以包括应变栅234a’、应变栅234b’、应变栅234c’和应变栅234d’。应变栅234a’和应变栅234b’的长度方向可以相互垂直。应变栅234a’和应变栅234d’的长度方向可以相互平行。应变栅234b’和应变栅234c’的长度方向可以相互平行。因此，应变栅234a’检测应变的方向可以与应变栅234b’检测应变的方向可以相互垂直，应变栅234a’检测应变的方向可以与应变栅234d’检测应变的方向可以相互平行，应变栅234b’检测应变的方向可以与应变栅234c’检测应变的方向可以相互平行，应变栅234c’检测应变的方向可以与应变栅234d’检测应变的方向可以相互垂直。应变栅234a’、应变栅234b’、应变栅234c’和应变栅234d’按照全桥模式电连接。假设应变的方向平行于应变栅234a’的长度方向，应变栅234a’和应变栅234b’检测同一位置变形量，应变栅234c’和应变栅234d’检测同一位置变形量。则应变栅234a’和应变栅234d’的电压差的电压差可以为V1，应变栅234b’的电压差和应变栅234c’的电压差均可以为0，则应变计234的总电压差为2×V1。垂直栅全桥应变计234有利于提高检测灵敏度。
结合图5A，观察膨胀检测组件230的A-A截面，可以得到图7A和图7B所示的截面图。下面结合图7A和图7B，阐述膨胀检测组件230检测电池210的膨胀信息的原理。
图7A示出了膨胀检测组件230处于初始状态时的示意性结构图。当膨胀检测组件230处于初始状态时，一个或多个电池210的总体膨胀量相对较小或忽略不计。因此，形变层233可以不发生形变或发生少量形变。在此情况下，形变层233和承压层231之间的最小间隔距离可以与应力集中层232的厚度(即应力集中层232在多个电池210的堆叠方向Y上的尺寸)相同，或者形变层233和承压层231之间的最小间隔距离可以略微小于应力集中层232的厚度。
在一个实施例中，应变计234可以在端板221和端板222可以夹紧电池210之前，设 置于膨胀检测组件230。膨胀检测组件230可以承受来自端板221和端板222作用的预紧力，从而形变层233可以发生微小变形。应变计234输出的信号可以反映形变层233的应变。也就是说，膨胀检测组件230可以具有检测预紧力的功能，有利于使电池210的夹紧力处于合适的范围内。
在另一个实施例中，在端板221和端板222可以夹紧电池210之前，可以将不具有应变计234的膨胀检测组件230设置于电池模组200内。膨胀检测组件230可以承受来自端板221和端板222作用的预紧力，从而形变层233可以发生微小变形。应变计234可以在端板221和端板222可以夹紧电池210之后，设置于膨胀检测组件230。应变计234基本检测不到因电池夹紧力导致的形变层233的应变量，有利于减少夹紧力对电池膨胀力检测的影响。
图7B示出了膨胀检测组件230处于检测状态时的示意性结构图。当一个或多个电池210发生膨胀时，膨胀检测组件230可以处于检测状态。在此情况下，一个或多个电池210可以在承压层231上施加电池膨胀力。承压层231和应力集中层232具有朝向电池模组200的某个端板221移动的趋势。结合图3A和图4A，电池模组200的端板221和端板222之间的间距相对固定，因此形变层233的靠近端板221的端面236在电池模组200内的位置可以相对固定，或者形变层233的靠近端板221的端面236在多个电池210的堆叠方向Y上的位移量相对较小甚至忽略不计。在承压层231和应力集中层232的作用下，形变层233的凹槽底面2352有朝向端板221突出的趋势。也就是说，形变层233的凹槽底面2352可能发生拉伸、弯折、翘曲等变形。凹槽底面2352的与应力集中层232连接的区域的变形量可能相对较小。凹槽底面2352的剩余区域变形量可能相对较大。在此情况下，形变层233和承压层231之间的最小间隔距离可以小于应力集中层232的厚度。
图5A和图5B所示的膨胀检测组件230的厚度相对较小，对电池模组200的能量密度影响相对较小。膨胀检测组件230可以在正常充放电场景中，检测电池模组200的静态压力，此时电池模组200的电池膨胀力可以相对较小。膨胀检测组件230可以在电池膨胀力迅速升高的场景中，检测电池模组200的动态压力变化。
由于应变计234可以检测凹槽底面2352的应变量，根据应变计234输出的应变量，可以确定一个或多个电池210的膨胀信息。例如，应变计234输出的应变量可以反映凹槽底面2352承受的应力，进而可以反映一个或多个电池210的电池膨胀力。又如，应变计234输出的应变量可以反映一个或多个电池210的膨胀量。
在电池膨胀力相同时，电池210膨胀的具体形式可以不同。例如，电池210的膨胀中心位于电池210的中心或重心。又如，电池210的膨胀中心偏离电池210的中心或重心。膨胀检测组件230可以响应电池膨胀力的作用而产生形变，使得在膨胀量复杂多样的场景下，膨胀检测组件230可以兼顾多种电池膨胀情况。也就是说，电池膨胀力的检测不受限于具体的电池膨胀量。
在一些实施例中，凹槽235的垂直于多个电池210的堆叠方向Y的截面形状可以与应力集中层232的垂直于多个电池210的堆叠方向Y的截面形状相互匹配。在图5A和图5B所示的实施例中，凹槽235和应力集中层232的垂直于多个电池210的堆叠方向Y的截面均可以为矩形。在其他实施例中，凹槽235和应力集中层232的垂直于多个电池210的堆叠方向Y的截面可以为其他形状。例如，在图8A和图8B所示的实施例中，凹槽235 和应力集中层232的垂直于多个电池210的堆叠方向Y的截面均可以为圆形。又如，在图9A和图9B所示的实施例中，凹槽235和应力集中层232的垂直于多个电池210的堆叠方向Y的截面均可以为椭圆形。凹槽235和应力集中层232的截面形状可以不限于不限于本申请已提供的实施例。
与图5A和图5B所示的实施例相比，在图8A、8B、9A和图9B所示的实施例中，沿多个电池210的堆叠方向Y观察，应力集中层232的投影面积与承压层231的投影面积的比值相对较小。根据上文所述原理，应力集中层232作用于形变层233的强度相对较大。因此，形变层233的凹槽底面2352的形变量可以相对较大。
在一种可能的情况下，沿多个电池210的堆叠方向Y观察，应力集中层232的投影面积与承压层231的投影面积的比值，可以与形变层233的变形量适配。也就是说，应力集中层232和承压层231的尺寸、形状等可以与形变层233的变形量适配。
当应力集中层232的投影面积与承压层231的投影面积的比值相对较大时，在相对较大的电池膨胀力的作用下，形变层233的变形量可以相对较小，形变层233上的应变计234可以用于检测相对大的电池膨胀力。
当应力集中层232的投影面积与承压层231的投影面积的比值相对较小时，在相对较小的电池膨胀力的作用下，形变层233的变形量可以相对较大，形变层233上的应变计234可以用于检测相对小的电池膨胀力。
在另一种可能的情况下，沿多个电池210的堆叠方向Y观察，应力集中层232的投影面积与形变层233的凹槽底面2352的投影面积的比值，可以与形变层233的变形量适配。也就是说，凹槽底面2352的尺寸、形状等可以与形变层233的变形量适配。
当应力集中层232的投影面积与形变层233的凹槽底面2352的投影面积的比值相对较小时，意味着形变层233的凹槽底面2352具有相对较大的可变形区域。因此，在电池膨胀力的作用下，形变层233的凹槽底面2352的形变量可以被尺寸相对较大的区域平摊，进而形变层233的凹槽底面2352的形变量可以相对较小。在此情况下，应变计234可以用于检测相对较大的电池膨胀力。
当应力集中层232的投影面积与形变层233的凹槽底面2352的投影面积的比值相对较大时，意味着形变层233的凹槽底面2352具有相对较小的可变形区域。因此，在电池膨胀力的作用下，形变层233的凹槽底面2352的形变量可以限缩于尺寸相对较小的区域内，进而形变层233的凹槽底面2352的形变量可以相对较大。在此情况下，应变计234可以用于检测相对较小的电池膨胀力。
膨胀检测组件230的检测量程还可以与形变层233的凹槽235的深度和形变层233的总厚度有关。通过合理设计凹槽235的深度、形变层233的总厚度，以及凹槽235的深度和形变层233的总厚度的比值，有利于使膨胀检测组件230具备相对合适的检测量程和检测精度。
当凹槽235的深度相对较小时，形变层233的凹槽底面2352的厚度较大，形变层233的凹槽底面2352的刚度相对较大，形变层233的凹槽底面2352相对不易变形，有利于使膨胀检测组件230在相对较大的电池膨胀力作用下检测并输出膨胀的信息。又由于凹槽235的深度相对较小，形变层233的凹槽底面2352在多个电池210的堆叠方向Y上的可变形空间可以相对较少，膨胀检测组件230的检测量程可能相对有限。
当凹槽235的深度相对较大时，形变层233的凹槽底面2352在多个电池210的堆叠方向Y上的可变形空间可以相对较多，有利于增加膨胀检测组件230的检测量程。当凹槽235的深度过大时，形变层233的凹槽底面2352的厚度较小，形变层233的凹槽底面2352的刚度相对较小，形变层233的凹槽底面2352相对容易变形，有利于在有效量程内相对敏感地检测电池膨胀力的变化情况。
应变计234的检测量程可以与形变层233的凹槽底面2352的形变量适配。在一种可能的情况下，当形变层233的凹槽底面2352与端板221接触时，或者当形变层233的凹槽底面2352与形变层233的凹槽开口2351齐平时，凹槽底面2352的形变量可能达到最大值。如果凹槽底面2352的形变量超过了应变计234的检测量程，则应变计234无法准确输出电池210的膨胀信息。如果电池210继续膨胀，则形变层233的凹槽底面2352的形变量变化不明显，在此情况下，即使应变计234具备更大的检测量程，应变计234也无法准确输出电池210的膨胀信息。通过适配应变计234的应变检测量程与形变层233的最大形变量，有利于选购合适的应变计234。
在一个实施例中，电池模组200内可以配置结构不同的两个膨胀检测组件230，这两个膨胀检测组件230可以分别用于不同的膨胀力量程，其中膨胀检测组件230a可以对应相对较小的膨胀力量程，膨胀检测组件230b可以对应相对较大的膨胀力量程。在电池模组200的电池膨胀力相对较小时，可以根据膨胀检测组件230a输出的结果，确定电池模组200的膨胀信息。在电池模组200的电池膨胀力相对较大时，可以根据膨胀检测组件230b输出的结果，确定电池模组200的膨胀信息。
结合图3B和图5A，以大面211的面积为148mm*102.5mm的电池210为例，阐述膨胀检测组件230的具体结构尺寸。电池210的电池膨胀力大约在0～20kN范围内波动。
承压层231的与电池210的大面211相对的端面的尺寸可以为148mm*102.5mm。也就是说，沿多个电池210的堆叠方向Y观察，承压层231的投影区域的尺寸可以为148mm*102.5mm。承压层231的厚度可以例如可以为2mm。承压层231的厚度相对合适，可以用于使承压层231的刚度处于合理范围，进而有利于减小承压层231的变形量，使电池膨胀力尽可能通过形变层233的凹槽底面2352的变形量体现；承压层231的厚度相对合适，还有利于使膨胀检测组件230的整体占用空间相对较小。
应力集中层232的与电池210的大面211相对的端面的尺寸可以为118mm*72.5mm。也就是说，沿多个电池210的堆叠方向Y观察，承压层231的投影区域的尺寸可以为118mm*72.5mm。应力集中层232的厚度可以例如可以为1mm。应力集中层232的厚度相对合适，可以用于使应力集中层232的刚度处于合理范围，进而有利于减小应力集中层232的变形量，使电池膨胀力尽可能通过形变层233的凹槽底面2352的变形量体现；应力集中层232的厚度相对合适，还有利于使膨胀检测组件230的整体占用空间相对较小。
应力集中层232的厚度还用于限制承压层231与形变层233接触。在电池膨胀力的作用下，应力集中层232的位移量，或者形变层233的凹槽底面2352的变形量，小于应力集中层232的厚度的情况下，承压层231可以不与形变层233接触，因此电池膨胀力可以基本或完全通过应力集中层232向形变层233传递。如果应力集中层232的位移量，或者形变层233的凹槽底面2352的变形量，等于或大于应力集中层232的厚度，承压层231可以与形变层233接触，因此电池膨胀力除了通过应力集中层232向形变层233传递，还 通过承压层231向形变层233传递。在此情况下，形变层233的凹槽底面2352的变形量可能无法准确反映电池膨胀力。
形变层233的端面237的尺寸可以为148mm*102.5mm。也就是说，沿多个电池210的堆叠方向Y观察，形变层233的投影区域的尺寸可以为148mm*102.5mm。形变层233在凹槽235外的厚度可以为3mm。形变层233在凹槽235内的厚度可以为2mm。即凹槽235的深度可以为1mm。在一个实施例中，凹槽开口2351的尺寸可以为128mm*82.5mm。在另一个实施例中，凹槽开口2351的尺寸可以为138mm*92.5mm。应变计234的厚度可以小于凹槽235的深度。由此，膨胀检测组件230的总厚度可以不超过6mm。
图10A至图10D示出了膨胀检测组件230受到一个或多个电池210的电池膨胀力的模拟结果。电池膨胀力可以为20kN。膨胀检测组件230的具体结构尺寸可以参照上文。
沿垂直于多个电池210的堆叠方向Y的方向观察膨胀检测组件230，可以得到图10A所示的膨胀检测组件230的位移模拟结果。当电池210膨胀时，电池210只可以在承压层231作用电池膨胀力，使承压层231和应力集中层232朝向形变层233移动。而形变层233受端板221限制，形变层233整体的位移量相对较小。承压层231和应力集中层232在多个电池210的堆叠方向Y上的位移量可以小于0.2mm。因此承压层231不会接触到形变层233。
沿多个电池210的堆叠方向Y观察膨胀检测组件230，可以得到图10B所示的膨胀检测组件230的位移模拟结果。在承压层231和应力集中层232的作用下，形变层233的凹槽底面2352的与应力集中层232相对的区域有背离承压层231移动的趋势。形变层233的边缘区域受端板221限制，形变层233的边缘区域的位移量相对较小。因此，位于形变层233的边缘区域和凹槽底面2352的与应力集中层232相连的区域之间的区域，即凹槽底面2352的边缘区域，可以发生拉伸变形。凹槽底面2352在多个电池210的堆叠方向Y上的突出高度可以小于0.15mm。因此凹槽底面2352不会接触到端板231，或者不会与凹槽开口2351齐平。
图10C示出了膨胀检测组件230沿X方向的应变张量的模拟结果。图10D示出了膨胀检测组件230沿Z方向的应变张量的模拟结果。如图10C和10D所示，凹槽底面2352的截面形状可以为矩形。对凹槽底面2352的边缘区域划分，可以得到边缘子区域2352a、边缘子区域2352b、边缘子区域2352c和边缘子区域2352d。边缘子区域2352a和边缘子区域2352c可以相对于凹槽235的长边平行设置，边缘子区域2352b和边缘子区域2352d可以相对于凹槽235的短边平行设置。凹槽235的长边可以相对于X方向平行，凹槽235的短边可以相对于Z方向平行。
边缘子区域2352a的中心位置和边缘子区域2352c的中心位置在X方向的应变张量相对较小。边缘子区域2352a的中心位置和边缘子区域2352c的中心位置在Z方向的应变张量相对较大。边缘子区域2352a的端部位置和边缘子区域2352c的端部位置在X方向的应变张量相对较大。边缘子区域2352a的端部位置和边缘子区域2352c的端部位置在Z方向的应变张量相对较大。边缘子区域2352a的中心位置和边缘子区域2352c的中心位置在X方向和Z方向的应变张量约为1000με。
边缘子区域2352b的中心位置和边缘子区域2352d的中心位置在Z方向的应变张量相对较小。边缘子区域2352b的中心位置和边缘子区域2352d的中心位置在X方向的应 变张量相对较大。边缘子区域2352b的端部位置和边缘子区域2352d的端部位置在Z方向的应变张量相对较大。边缘子区域2352b的端部位置和边缘子区域2352d的端部位置在Z方向的应变张量相对较大。
根据膨胀检测组件230的冯·米塞斯(Von Mises)应力的模拟结果，凹槽底面2352的四角上的应力，可以大于凹槽底面2352的其他区域上的应力。边缘子区域2352a的中心位置和边缘子区域2352c的中心位置的应力可以约为100～300Mpa。由于边缘子区域2352a的中心位置和边缘子区域2352c的中心位置承受的应力相对较小，因此边缘子区域2352a的中心位置和边缘子区域2352c的中心位置更容易发生弹性恢复。由此有利于实现膨胀检测组件230循环多次工作。
沿多个电池210的堆叠方向Y观察膨胀检测组件230，可以得到图11A至图11D所示的示意性结构图。
在一些实施例中，图11A至图11D示出了形变层233的凹槽235示意性结构图。图11A至图11D中虚线框围成的区域示出了应力集中层232在凹槽底面2352的投影区域，即上述凹槽底面中间区域；图11A至图11D中斜线填充的区域示出了凹槽底面2352的围绕于应力集中层232的投影区域的外周的区域，即上述凹槽底面边缘区域。应变计234可以设置于凹槽底面边缘区域。
在另一些实施例中，图11A至图11D示出了形变层233的靠近应力集中层232的端面236的示意性结构图。图11A至图11D中虚线框围成的区域示出了该端面236的与应力集中层232连接的区域，即上述形变区域的中间部分；图11A至图11D中斜线填充的区域示出了该端面236的位于应力集中层232以外的区域，即上述形变区域的边缘部分。也就是说，应变计234可以设置于形变区域的边缘部分。
下面以应变计234设置于凹槽235内的实施例，阐述应变计234的几种可能的设置位置。应变计234在形变层233的靠近应力集中层232的端面236的具体位置，可以参照应变计234设置于凹槽235内的实施例。
在图11A所示的实施例中，应变计234可以设置于凹槽235的对称轴上。如图11A所示，凹槽235可以相对于对称轴x和对称轴z对称。对称轴x和对称轴z可以相对垂直设置。对称轴x和对称轴z可以相对于多个电池210的堆叠方向Y垂直设置。对称轴x可以相对于凹槽底面2352的长边平行设置。对称轴y可以相对于凹槽底面2352的短边平行设置。膨胀检测组件230可以包括应变计2341、应变计2342、应变计2343和应变计2344。应变计2341和应变计2343可以设置于对称轴z，且分别位于凹槽235的两侧。应变计2342和应变计2344可以设置于对称轴x，且分别位于凹槽235的两侧。
结合图10C和图10D所示的模拟结果，应变计2341和应变计2343可以主要用于检测在对称轴z上的应变，进而反映电池膨胀力在对称轴z或Z方向上的分力。应变计2341和应变计2343输出的信号值还可以用于抵消应变计2341和应变计2343自身引入的误差。应变计2342和应变计2344可以主要用于检测在对称轴x上的应变，进而反映电池膨胀力在对称轴x或X方向上的分力。应变计2342和应变计2344输出的信号值还可以用于抵消应变计2342和应变计2344自身引入的误差。在图11A所示的实施例中，应变计234可以用于输出对称轴方向的电池膨胀力，有利于获取在对称轴方向上的膨胀信息。
在图11B所示的实施例中，应变计234可以靠近凹槽底面2352的一个角设置。如图 11B所示，凹槽底面2352的边缘区域可以包括边缘子区域2352a、边缘子区域2352b、边缘子区域2352c和边缘子区域2352d。边缘子区域2352a和边缘子区域2352c可以相对于凹槽235的长边平行设置，边缘子区域2352b和边缘子区域2352d可以相对于凹槽235的短边平行设置。边缘子区域2352a和边缘子区域2352d的交界区域可以是凹槽底面2352的角1。边缘子区域2352a和边缘子区域2352b的交界区域可以是凹槽底面2352的角2。边缘子区域2352b和边缘子区域2352c的交界区域可以是凹槽底面2352的角3。边缘子区域2352d和边缘子区域2352d的交界区域可以是凹槽底面2352的角4。
膨胀检测组件230可以包括应变计2341、应变计2342、应变计2343和应变计2344。应变计2341可以设置于边缘子区域2352a且靠近凹槽底面2352的角1设置。应变计2342可以设置于边缘子区域2352a且靠近凹槽底面2352的角2设置。应变计2343可以设置于边缘子区域2352c且靠近凹槽底面2352的角3设置。应变计2344可以设置于边缘子区域2352c且靠近凹槽底面2352的角4设置。在其他实施例中，应变计2341可以设置于边缘子区域2352d且靠近凹槽底面2352的角1设置。应变计2342可以设置于边缘子区域2352b且靠近凹槽底面2352的角2设置。应变计2343可以设置于边缘子区域2352b且靠近凹槽底面2352的角3设置。应变计2344可以设置于边缘子区域2352d且靠近凹槽底面2352的角4设置。
结合图10C和图10D所示的模拟结果，在凹槽底面2352的角上的应变既具有沿X方向的分量，也具有沿Z方向的分量。应变计2341、应变计2342、应变计2343和应变计2344输出的信号值可以反映一个或多个电池210的总电池膨胀力。
在凹槽底面2352的角上的应变与凹槽底面2352的形变峰值有关。在实际检测时，形变峰值可能具有相对较大的不稳定性，例如形变峰值可能受局部特殊形变影响，因此形变峰值可能无法相对准确地反映凹槽底面2352的整体受力情况。由于应变计234在凹槽底面2352上的位置与凹槽底面2352的角具有一定距离，有利于降低应变计234检测到局部特殊形变的可能性，减少局部特殊形变对总体膨胀信息的影响。
应理解，膨胀检测组件230可以包括数量更多或更少的应变计234。在图11C所示的实施例中，膨胀检测组件230可以仅包括图11A所示的实施例中的应变计2341和应变计2342；其中应变计2341可以主要用于检测检测在对称轴z上的应变，进而反映电池膨胀力在对称轴z或Z方向上的分力；应变计2342可以主要用于检测检测在对称轴x上的应变，进而反映电池膨胀力在对称轴x或X方向上的分力。
在图11D所示的实施例中，膨胀检测组件230可以包括应变计2345。应变计2345可以设置于边缘子区域2352a和边缘子区域2352d的交界区域，即应变计2345设置于凹槽底面2352的角1。应变计2345可以用于检测凹槽底面2352的整体形变情况，进而应变计2345输出的信号值可以反映一个或多个电池210的总电池膨胀力。
图12示出了在图11A所示实施例中的应变计2341至应变计2344输出信号的情况。如图12所示，应变计2341至应变计2344输出的信号量可以与电池210的电池膨胀力大体呈线性关系。也就是说，根据应变计234的信号量，和图12所示的应变计234的信号量-电池膨胀力的关系，可以确定电池210的电池膨胀力。
图13示出了本申请实施例提供的一种膨胀检测组件230的示意性结构图。膨胀检测组件230可以包括馈电端和接地端。膨胀检测组件230可以通过馈电端和接地端形成回 路。馈电端和接地端可以用于为膨胀检测组件230内的部件馈电。膨胀检测组件230还可以包括一个或多个应变计234。应变计234可以包括输出端S+和输出端S-。输出端S+和输出端S-的电压差，以及输出端S+和输出端S-导通的电流可以反映应变计234的电阻。在一种可能的情况下，输出端S-可以为应变计234的接地端。在图13所示的实施例中，膨胀检测组件230可以包括应变计2341、应变计2342、应变计2343和应变计2344。应变计2341、应变计2342、应变计2343和应变计2344可以与图11A或图11B所示的应变计2341、应变计2342、应变计2343和应变计2344对应。
在一些实施例中，膨胀检测组件230还可以包括模拟前端(analog front end，AFE)。来自应变计234的信号可以输入至AFE。AFE可以包括模数(analogue-to-digital，AD)转换器，用于将应变计234输出的模拟信号转换为数字信号。
在一些实施例中，膨胀检测组件230还可以包括控制单元。控制单元例如可以是微控制单元(microcontroller unit，MCU)。控制单元可以用于对应变计234输出的信号进行处理。在一个实施例中，控制单元可以对应变计234输出的信号进行校正、去直流量、去除噪音信号等。噪音信号例如可以是受温度、预应力等影响而产生的误差信号。在一种可能的情况下，膨胀检测组件230可以通过控制单元输出电池的膨胀信息。膨胀检测组件230可以向图2所示的BMS控制模块132或BMS控制模块133输出电池210的膨胀信息。
图14是本申请实施例提供的一种获取电池膨胀力的方法的示意性流程图。
1401，获取应变计234输出的信号1。
1402，根据所述信号1和所述应变计234的膨胀检测参数，获取膨胀信息，所述膨胀信息用于指示电池膨胀力。
应变计234的输入电压可以不变。应变计234发生形变后，应变计234的电阻可以发生变化，应变计234导通的电流可以发生变化，应变计234的输出端S+和输出端S-的电压差可以发生变化。结合图12所示的示意图，执行图14所示方法的处理模块(例如图2所示的BMS控制模块132或BMS控制模块133)可以根据应变计234的电压差，以及应变计234的电压差-电池膨胀力的关系，获取电池膨胀力。其中，膨胀检测参数可以指示应变计234的电压差-电池膨胀力的关系。在一些实施例中，膨胀检测参数可以包括应变计234的电压差-电池膨胀力的斜率。假设应变计234的电压差-电池膨胀力的斜率为k，应变计234的输出端S+和输出端S-的电压差为V，电池膨胀力为F可以满足：F＝/≈kV。在另一些实施例中，膨胀检测参数可以包括应变计234的多个电压差和多个电池膨胀力，应变计234的多个电压差和多个电池膨胀力一一对应。在又一些实施例中，应变计234示出的信号可以被转换为应变量。膨胀检测参数可以包括应变计234检测到的应变量-电池膨胀力的斜率。在再一些实施例中，膨胀检测参数可以包括应变计234检测到的多个应变量和多个电池膨胀力，应变计234的多个应变量和多个电池膨胀力一一对应。
在一些实施例中，1402可以执行于检测模式。获取电池膨胀力的方法还可以包括：1403，在校准模式下，根据当前施加于膨胀检测组件230的作用力和应变计234当前输出的信号2，确定应变计234的膨胀检测参数。1403可以是可选的步骤。
在使用应变计234之前，可以对应变计234进行校准。通过对膨胀检测组件230施加预设作用力，使得膨胀检测组件230的应变计234可以检测到形变。应变计234输出的信号可以与预设作用力匹配。根据应变计234输出的信号和预设作用力之间的关系，可以确 定膨胀检测参数。膨胀检测参数可以被存储于存储器。在应变计234正常工作时，通过从存储器读取膨胀检测参数，可以确定应变计234输出的信号所对应的电池膨胀力。
在一种可能的场景下，当电池210尚未出厂，膨胀检测组件230可以进入校准模式；当电池210出厂后，膨胀检测组件230可以由校准模式转变为检测模式；当电池210处于维修状态时，膨胀检测组件230可以由检测模式转变为校准模式；当电池210维修完毕后，膨胀检测组件230可以由校准模式转变为检测模式。结合图13所示的实施例，膨胀检测组件230的控制单元可以用于更新模式标识，模式标识可以用于指示膨胀检测组件230处于校准模式或检测模式。
在一些实施例中，膨胀检测组件230可以包括图11A所示的应变计2341、应变计2342、应变计2343和应变计2344，获取电池膨胀力的方法还可以包括：根据应变计2341、应变计2342、应变计2343和应变计2344输出的信号，确定电池膨胀力的作用位置，或者校准与膨胀检测组件230的中心位置相关的膨胀检测参数。
下面结合图15，阐述确定电池膨胀力的作用位置的原理，以及校准膨胀检测组件230的中心位置的原理。有关应变计2341、应变计2342、应变计2343和应变计2344的相关说明参照图11A所示的实施例。
如图15，P0示出了膨胀检测组件230的中心位置。膨胀检测组件230的中心位置可以对应膨胀检测组件230的中心或重心，还可以对应端板221的中心或重心，还可以对应电池210的中心或重心。在一种可能的情况下，电池210的中心或重心在膨胀检测组件230的投影可以与膨胀检测组件230的中心位置对齐。
在膨胀检测组件230处于校准模式的情况下，可以在膨胀检测组件230的中心位置P0施加作用力F0。应变计2341、应变计2342、应变计2343和应变计2344可以输出信号，分别为S1(F0,P0)、S2(F0,P0)、S3(F0,P0)、S4(F0,P0)。
S1(F0,P0)＝F0*A1*z1/2；
S2(F0,P0)＝F0*A2*x2/2；
S3(F0,P0)＝F0*A3*z3/2；
S4(F0,P0)＝F0*A4*x4/2。
其中A1、A2、A3和A4可以分别是应变计2341、应变计2342、应变计2343和应变计2344的应变计系数。应变计系数通常与应变计234自身属性相关。z1、x2、z3和x4可以分别是应变计2341、应变计2342、应变计2343和应变计2344在膨胀检测组件230上的位置信息。
结合图11A和图15，凹槽底面2352的边缘区域可以包括边缘子区域2352a、边缘子区域2352b、边缘子区域2352c和边缘子区域2352d。边缘子区域2352a和边缘子区域2352c可以分别位于凹槽底面2352的两侧，且相对于X方向或凹槽235的长边平行设置；边缘子区域2352b和边缘子区域2352d可以分别位于凹槽底面2352的两侧，且相对于Z方向或凹槽235的短边平行设置。
应变计2341设置于边缘子区域2352a的中心，边缘子区域2352a可以位于凹槽槽壁2353和应力集中层232在凹槽底面2352的投影区域之间。z1可以是应变计2341与凹槽槽壁2353之间的间距，或者z1可以是应变计2341与凹槽槽壁2353在Z方向上的距离。
应变计2342设置于边缘子区域2352b的中心，边缘子区域2352b可以位于凹槽槽壁 2354和应力集中层232在凹槽底面2352的投影区域之间。x2可以是应变计2342与凹槽槽壁2354之间的间距，或者x2可以是应变计2342与凹槽槽壁2354在X方向上的距离。
应变计2343设置于边缘子区域2352c的中心，边缘子区域2352c可以位于凹槽槽壁2355和应力集中层232在凹槽底面2352的投影区域之间。Z3可以是应变计2343与凹槽槽壁2355之间的间距，或者z3可以是应变计2343与凹槽槽壁2355在Z方向上的距离。
应变计2344设置于边缘子区域2352d的中心，边缘子区域2352d可以位于凹槽槽壁2356和应力集中层232在凹槽底面2352的投影区域之间。X4可以是应变计2344与凹槽槽壁2356之间的间距，或者x4可以是应变计2344与凹槽槽壁2356在X方向上的距离。
由于A1、A2、A3、A4、z1、x2、z3和x4均为常数，因此可以将A1*z1作为应变计2341的膨胀检测参数，将A2*x2作为应变计2342的膨胀检测参数，将A3*z3作为应变计2343的膨胀检测参数，将A4*x4作为应变计2344的膨胀检测参数。
在一些实施例中，可以根据作用力F0和应变计2341、应变计2342、应变计2343和应变计2344输出的信号，校准膨胀检测参数：
A1*z1＝2*S1(F0,P0)/F0；
A2*x2＝2*S2(F0,P0)/F0；
A3*z3＝2*S3(F0,P0)/F0；
A4*x4＝2*S4(F0,P0)/F0。
在膨胀检测组件230处于检测模式的情况下，可以获取到应变计2341、应变计2342、应变计2343和应变计2344输出的信号，分别为S1(F,P)、S2(F,P)、S3(F,P)和S4(F,P)。F表示待检测的电池膨胀力，P表示电池膨胀力F在膨胀检测组件230的作用位置，即等效压力作用中心。P的坐标可以为(Px,Pz)，Px可以指P在X方向上的坐标，Pz可以指P在Z方向上的坐标。
S1(F,P)＝F*A1*z1*(lz/2-Pz)/lz；
S2(F,P)＝F*A2*x2*(lx/2-Px)/lx；
S3(F,P)＝F*A3*z3*(lz/2-Pz)/lz；
S4(F,P)＝F*A4*x4*(lx/2-Px)/lx。
其中，lx为凹槽底面2352在X方向的尺寸，lz为凹槽底面2352在Z方向的尺寸。结合校准后的膨胀检测参数，可以根据以下公式推导出电池膨胀力F和电池膨胀力F在膨胀检测组件230的作用位置P：
S1(F,P)＝(2*S1(F0,P0)*F*(lz/2-Pz))/(lz*F0)；
S2(F,P)＝(2*S2(F0,P0)*F*(lx/2-Px))/(lx*F0)；
S3(F,P)＝(2*S3(F0,P0)*F*(lz/2-Pz))/(lz*F0)；
S4(F,P)＝(2*S4(F0,P0)*F*(lx/2-Px))/(lx*F0)。
图16A和图16B示出了本申请实施例提供的一种电池模组200的实验结果。其中，图16A示出了电池模组200的温度和电压的监测结果，图16B示出了电池模组200的电池膨胀力的监测结果。
如图16A所示，在电池模组200正常工作时，电池模组200的温度可以相对平稳，电池模组200的电压可以稳步上升。在电池模组200失效前的10～30分钟内，电池模组200的温度仍保持相对平稳的状态，电池模组200的电压仍保持稳步上升的状态。也就是说， 在电压和温度方面，电池模组200在失效前的10～30分钟内的表现，与正常工作时的表现差异较小。然而，当电池模组200失效发生时，电池模组200的电压和温度才出现剧烈变化。因此无法根据电压和温度，预判电池模组200是否即将失效。
如图16B所示，在电池模组200正常工作时，电池模组200的电池膨胀力相对较小，且电池模组200的电池膨胀力可以略有上升。在电池模组200失效前的30分钟内，电池模组200的电池膨胀力可以维持在相对中等的范围内，电池模组200的电池膨胀力可以略有上升。也就是说，在电池膨胀力方面，电池模组200在失效前的30分钟内的表现与电正常工作时的表现略有不同。在电池模组200失效前的10分钟内，电池模组200的电池膨胀力可以陡然升高，电池模组200的电池膨胀力可以上升至正常状态下的数倍。也就是说，在电池膨胀力方面，电池模组200在失效前的10分钟内的表现与正常工作时的表现差异较大。因此，根据电池膨胀力可以预判电池模组200是否即将失效。
在一些实施例中，用电装置100可以实时监测电池模组200的电池膨胀力。在另一些实施例中，用电装置100可以在以下情况监测电池模组200的电池膨胀力：充电状态、行驶状态和停车状态。如果用电装置100监测到的电池膨胀力的上升速度、电池膨胀力的具体数值处于正常范围内，则可以判断电池210健康状态相对良好。在不同状态下，电池膨胀力的正常表现可以略有不同。当检测到电池膨胀力出现异常后，可以执行电池210健康管理操作。
在一些实施方式中，当检测到电池膨胀力上升斜率大于预设斜率时，可以意味着电池模组200的电池膨胀力异常升高，电池模组200在短时间(例如10分钟)内失效的可能性相对较大。在一种可能的情况下，用电装置100可以切断电池模组200的通路，使电池模组200停止工作。在另一种可能的情况下，用电装置100可以向用户发出警告，例如提示用户电池210失控；又如提示用户采取急救措施，急救措施例如为紧急停车、报警求助、降温、断电、灭火。
在另一些实施方式中，当检测到电池膨胀力大于预设电池膨胀力1时，可以意味着电池模组200的电池膨胀力相对较大内，电池模组200在一段时间(例如10分钟)内失效的可能性相对较大。在一种可能的情况下，用电装置100可以切断电池模组200的通路，使电池模组200停止工作。在另一种可能的情况下，用电装置100可以向用户发出警告，例如提示用户电池210失控；又如提示用户采取急救措施，急救措施例如为紧急停车、报警求助、降温、断电、灭火、主动进行电池压强释放以防止爆炸、丢弃电池模组200或电池包130。
在又一些实施方式中，当检测到电池膨胀力大于预设电池膨胀力2(预设电池膨胀力2小于预设电池膨胀力1，例如预设电池膨胀力1可以为预设电池膨胀力2的数倍)时，可以意味着电池模组200的电池膨胀力处于相对中等的范围内，电池模组200在一段时间(例如30分钟)内失效的可能性相对较大。在一种可能的情况下，用电装置100可以降低电池模组200的使用功率，用电装置100可以限制电池模组200的输出电流和工作时间。在另一种可能的情况下，用电装置100可以采取为电池模组200降温。在又一种可能的情况下，用电装置100可以向用户提示电池风险和维修建议。
图17A是本申请实施例提供的一种电池模组200的示意性结构图。图17B是图17A所示的一种电池模组200的爆炸图。与图3所示的实施例类似，电池模组200可以包括多 个电池210，以及相对设置的端板221和端板222。多个电池210、端板221和端板222沿堆叠方向Y排列，多个电池210夹设于端板221和端板222之间。与图3所示的实施例不同，图17A和图17B所示的电池模组200还包括结构不同的膨胀检测组件230。
图18A是本申请实施例提供的另一种电池模组200的示意性结构图。图18B是图18A所示的一种电池模组200的爆炸图。在图18A和图18B所示的实施例中，电池210可以包括两个膨胀检测组件230，其中一个膨胀检测组件230a可以位于电池210a和端板221之间，另一个膨胀检测组件230b可以位于电池210b和端板222之间，电池210a可以是多个电池210中最靠近端板221的电池210，电池210b可以是多个电池210中最靠近端板222的电池210。
在其他可能的情况下，膨胀检测组件230还可以位于相邻两个电池210之间。
图17A、图17B、图18A和图18B所示的膨胀检测组件230可以参照图19A至图19C所示的实施例。图19A至图19C示出了本申请实施例提供的三种膨胀检测组件230的示意性结构图。
如图19A至图19C所示，膨胀检测组件230可以包括形变层233和应变计234。形变层233可以包括端面237和端面236。结合图17A或图18A，端面237可以与电池210a接触，端面236可以靠近或面向端板221设置。在一个实施例中，膨胀检测组件230可以夹设于端板221和电池210a之间，端面236的位于凹槽开口2351以外的区域可以与端板221接触。当电池210膨胀时，电池210可以在端面237作用电池膨胀力。端面236可以设置有凹槽235。形变层233在凹槽235内的厚度(即沿多个电池210的堆叠方向Y的尺寸)可以相对较小，形变层233在凹槽235外的厚度可以相对较大。因此在电池膨胀力的作用下，形变层233的凹槽底面2352可以相对容易变形。
应变计234可以设置于形变层233。应变计234可以用于检测形变层233的凹槽底面2352的变形量。在第一种实施方式中，应变计234可以设置于形变层233的凹槽底面2352。在第二种实施方式中，应变计234可以设置于形变层233的端面237，且部分或全部应变计234位于端面237的与凹槽底面2352相对的区域内。也就是说，应变计234可以设置于形变层233和电池210a之间。部分或全部应变计234可以位于凹槽底面2352在端面237的投影区域内。
在一些实施例中，沿多个电池210的堆叠方向Y观察，形变层233的投影区域可以与电池210的投影区域完全重合或基本重合。如果形变层233的投影区域位于电池210的投影区域内，且形变层233的投影区域与电池210的投影区域面积相差较大，则电池210的一部分可以与形变层233接触，剩余部分可能位于形变层233以外。当电池210膨胀时，电池210的与形变层233接触的区域可以受形变层233的阻挡，从而在一定程度上约束电池210的膨胀；而电池210的位于形变层233以外的区域无法受形变层233的阻挡，从而可能导致电池210局部异常膨胀。电池210局部异常膨胀相对难以恢复正常，相对容易造成安全事故。
当一个或多个电池210发生膨胀时，膨胀检测组件230可以处于检测状态。在此情况下，一个或多个电池210的总体膨胀量相对较大。由于电池模组200的端板221和端板222之间的间距相对固定，形变层233的靠近端板221的端面236在电池模组200内的位置可以相对固定，或者形变层233的靠近端板221的端面236在多个电池210的堆叠方向 Y上的位移量相对较小甚至忽略不计。形变层233的端面237可以承受电池膨胀力，形变层233的凹槽底面2352有朝向端板221突出的趋势。也就是说，形变层233的凹槽底面2352可能发生拉伸、弯折、翘曲等变形。与形变层233的端面237接触的电池210a的膨胀形状，可以与形变层233的凹槽底面2352的变形情况匹配。从而，根据应变计234输出的应变量，可以确定一个或多个电池210的膨胀信息。
结合图17B和图19A，以大面211的面积为148mm*102.5mm的电池210为例，阐述膨胀检测组件230的具体结构尺寸。电池210的电池膨胀力大约在0～20kN范围内波动。
形变层233的端面237的尺寸可以为148mm*102.5mm。也就是说，沿多个电池210的堆叠方向Y观察，形变层233的投影区域的尺寸可以为148mm*102.5mm。形变层233在凹槽235外的厚度可以为5mm。形变层233在凹槽235内的厚度可以为4mm。即凹槽235的深度可以为1mm。在一个实施例中，凹槽开口2351的尺寸可以为128mm*82.5mm。在另一个实施例中，凹槽开口2351的尺寸可以为138mm*92.5mm。应变计234的厚度可以小于凹槽235的深度。由此，膨胀检测组件230的总厚度可以不超过5mm。
在图19A所示的实施例中，凹槽235的垂直于多个电池210的堆叠方向Y的截面可以为矩形。在其他实施例中，凹槽235的垂直于多个电池210的堆叠方向Y的截面可以为其他形状。在图19B所示的实施例中，凹槽235的垂直于多个电池210的堆叠方向Y的截面可以为圆形。在图19C所示的实施例中，凹槽235的垂直于多个电池210的堆叠方向Y的截面可以为椭圆形。凹槽235的截面形状可以不限于不限于本申请已提供的实施例。
与图19A所示的实施例相比，在图19B和19C所示的实施例中，沿多个电池210的堆叠方向Y观察，凹槽底面2352的投影面积与电池210的投影面积的比值相对较小。端面237可以包括中间变形区域和边缘变形区域。沿多个电池210的堆叠方向Y观察，中间变形区域的投影区域可以与凹槽底面2352的投影区域重合，边缘变形区域可以与凹槽底面2352的投影区域无交叉。边缘变形区域可以围绕于凹槽底面2352的投影区域的外周。中间变形区域是反映电池膨胀力的主要区域。中间变形区域占端面237的比例越小，意味着应变计234能够捕捉到的电池210的膨胀信息越少。中间变形区域占端面237的比例越大，意味着应变计234能够捕捉到的电池210的膨胀信息越多。
膨胀检测组件230的检测量程还可以与形变层233的凹槽235的深度和形变层233的总厚度有关。应变计234的检测量程可以与形变层233的凹槽底面2352的形变量适配。在一个实施例中，电池模组200内可以配置结构不同的两个膨胀检测组件230，这两个膨胀检测组件230可以分别用于不同的膨胀力量程。
图20示出了应变计234在凹槽235内的几种可能的位置。应变计234在形变层233的端面237的具体位置，可以参照应变计234设置于凹槽235内的实施例。图20A、图20D、图20G示出了应变计234在矩形截面的凹槽235内的几种可能的位置。图20B、图20E、图20H示出了应变计234在圆形截面的凹槽235内的几种可能的位置。图20C、图20F、图20I示出了应变计234在椭圆形截面的凹槽235内的几种可能的位置。
在图20A、图20B、图20C所示的实施例中，应变计234可以靠近凹槽235的槽壁设置。凹槽底面2352的靠近槽壁的区域的变形量可以相对较小。在图20A、图20B、图20C所示的实施例中，应变计234可以用于检测相对较大的电池膨胀力。在一种可能的情况下， 应变计234可以设置于凹槽235的对称轴上。应变计234可以用于输出对称轴方向的电池膨胀力，有利于获取在对称轴方向上的膨胀信息。
在图20D、图20E、图20F所示的实施例中，应变计234与凹槽235槽壁之间可以具有间距a，且应变计234与凹槽底面2352的中心之间可以具有间距b。间距a和间距b可以相同或大致相同或差别相对较小。应变计234的位置相对靠近凹槽底面2352的中心，因此应变计234所在的区域可以发生相对较大的变形量。在图20D、图20E、图20F所示的实施例中，应变计234可以用于检测相对较小的电池膨胀力，且在有效量程内相对敏感地检测电池膨胀力的变化情况。在一种可能的情况下，应变计234可以设置于凹槽235的对称轴上。应变计234可以用于输出对称轴方向的电池膨胀力，有利于获取在对称轴方向上的膨胀信息。
应理解，膨胀检测组件230可以包括数量更多或更少的应变计234。在图20G、图20H、图20I所示的实施例中，膨胀检测组件230可以仅包括一个应变计234。在一种可能的情况下，应变计234可以设置于凹槽底面2352的中心。凹槽底面2352的中心通常对应电池210膨胀量最大的位置，由此有利于快速检测到电池210膨胀异常的情况。
本申请实施例提供了一种膨胀检测组件、电池模组、电池包和用电装置。通过在电池模组设置膨胀检测组件，使电池模组的膨胀信息可以被检测到，进而有利于准确评估电池模组的状态，有利于针对电池模组失效进行预判。膨胀检测组件在电池膨胀力的作用下发生变形。通过应变计检测到膨胀检测组件的变形情况，进而获取膨胀检测组件承受的电池膨胀力。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (22)

  1. 一种电池模组(200)，其特征在于，包括：
    电池(210)和膨胀检测组件(230)，所述膨胀检测组件(230)包括：
    形变层(233)，所述形变层(233)包括第一端面(237)和第二端面(236)，所述第一端面(237)靠近所述电池(210)设置，所述第二端面(236)远离所述电池(210)设置，所述形变层(233)的第二端面(236)设置有凹槽(235)；
    应变计(234)，所述应变计(234)设置于所述形变层(233)，所述应变计(234)用于检测所述凹槽(235)的凹槽底面(2352)的应变。
  2. 根据权利要求1所述的电池模组(200)，其特征在于，所述膨胀检测组件(230)还包括承压层(231)和应力集中层(232)，所述应力集中层(232)位于所述承压层(231)和所述形变层(233)之间，所述承压层(231)与所述电池(210)相邻，所述凹槽底面(2352)可在所述应力集中层(232)的作用下形变。
  3. 根据权利要求2所述的电池模组(200)，其特征在于，所述应变计(234)设置于所述凹槽底面(2352)上，且位于所述凹槽底面(2352)的与所述应力集中层(232)相对的区域外。
  4. 根据权利要求3所述的电池模组(200)，其特征在于，所述凹槽底面(2352)的形状为矩形，所述凹槽底面(2352)包括边缘子区域(2352a，2352b)，所述边缘子区域(2352a，2352b)位于所述凹槽(235)的槽壁和所述凹槽底面(2352)的与所述应力集中层(232)相对的区域之间，所述边缘子区域(2352a，2352b)相对于所述凹槽底面(2352)的长边或短边平行设置；
    所述应变计(234)设置于所述边缘子区域(2352a，2352b)的中心，或者，所述应变计(234)设置于所述边缘子区域(2352a，2352b)的端部。
  5. 根据权利要求2所述的电池模组(200)，其特征在于，所述第一端面(237)包括与所述凹槽底面(2352)相对设置的形变区域，所述应变计(234)设置于所述形变区域，且位于所述形变区域的与所述应力集中层(232)相对的区域外。
  6. 根据权利要求5所述的电池模组(200)，其特征在于，所述应变计(234)设置于所述边缘部分的对称轴上，或者，所述应变计(234)设置于所述边缘部分的角上。
  7. 根据权利要求2至6中任一项所述的电池模组(200)，其特征在于，所述承压层(231)的刚度大于或等于所述凹槽底面(2352)的刚度。
  8. 根据权利要求2至7中任一项所述的电池模组(200)，其特征在于，所述应力集中层(232)的刚度大于或等于所述凹槽底面(2352)的刚度。
  9. 根据权利要求2至8中任一项所述的电池模组(200)，其特征在于，所述承压层(231)、所述应力集中层(232)和所述形变层(233)一体成型。
  10. 根据权利要求1所述的电池模组(200)，其特征在于，所述第一端面(237)与所述电池(210)相邻。
  11. 根据权利要求10所述的电池模组(200)，其特征在于，
    所述应变计(234)设置于所述凹槽底面(2352)；或者，
    所述第一端面(237)包括与所述凹槽底面(2352)相对设置的形变区域，所述应变计(234)设置于所述形变区域内。
  12. 根据权利要求1至11中任一项所述的电池模组(200)，其特征在于，所述形变层(233)的材料为以下中的任一项：合金钢、铝合金和钛合金。
  13. 根据权利要求1至12中任一项所述的电池模组(200)，其特征在于，所述凹槽底面(2352)的形状为以下中的任一项：矩形、圆形和椭圆形。
  14. 根据权利要求1至13中任一项所述的电池模组(200)，其特征在于，所述电池模组(200)还包括端板(221)，所述膨胀检测组件(230)夹设于所述端板(221)和所述电池(210)之间。
  15. 一种电池包(130)，其特征在于，包括如权利要求1至14中任一项所述的电池模组(200)。
  16. 一种电池包(130)，其特征在于，包括：
    电池(210)和膨胀检测组件(230)，所述膨胀检测组件(230)包括：
    形变层(233)，所述形变层(233)包括第一端面(237)和第二端面(236)，所述第一端面(237)靠近所述电池(210)设置，所述第二端面(236)远离所述电池(210)设置，所述形变层(233)的第二端面(236)设置有与所述电池(210)相对的凹槽(235)；
    应变计(234)，所述应变计(234)设置于所述形变层(233)，所述应变计(234)用于检测所述凹槽(235)的凹槽底面(2352)的应变。
  17. 根据权利要求15或16所述的电池包(130)，其特征在于，所述电池包(130)还包括电池管理系统BMS控制模块(132,133)，所述BMS控制模块(132,133)用于获取所述应变计(234)输出的信号。
  18. 一种用电装置(100)，包括如权利要求15至17中任一项所述的电池包(130)。
  19. 一种获取膨胀信息的方法，包括：
    获取所述应变计输出的第一信号；
    根据所述第一信号和膨胀检测参数，获取膨胀信息，所述膨胀检测参数用于指示所述第一信号和电池膨胀力的关系，所述膨胀信息用于指示所述电池膨胀力；
    其中，所述膨胀检测参数包括以下中的至少一项：
    所述应变计的电压差-所述电池膨胀力的斜率；
    所述应变计的多个电压差和多个电池膨胀力，所述多个电压差和所述多个电池膨胀力一一对应；
    所述应变计检测到的应变量-所述电池膨胀力的斜率；
    所述应变计检测到的多个应变量和多个电池膨胀力，所述多个应变量和所述多个电池膨胀力一一对应；
    所述应变计在所述膨胀检测组件上的位置信息；
    所述应变计的应变计系数；
    与所述膨胀检测组件的中心位置相关的参数。
  20. 根据权利要求19所述的方法，其特征在于，所述方法还包括：
    根据所述第一信号，确定电池膨胀力的作用位置。
  21. 根据权利要求19或20所述的方法，其特征在于，所述方法还包括：
    在校准模式下，获取所述应变计输出的第二信号；
    根据施加于所述膨胀检测组件的作用力和所述第二信号，校准所述膨胀检测参数。
  22. 根据权利要求19至21中任一项所述的方法，其特征在于，所述方法还包括：
    当所述电池膨胀力大于预设电池膨胀力时，或者，当所述电池膨胀力的上升斜率大于预设斜率时，
    执行以下中的一个或多个操作：
    降低电池的使用功率；
    降低电池的温度；
    对电池进行压力释放；
    发出警告；
    紧急停车。
PCT/CN2023/089982 2022-04-29 2023-04-23 电池模组、电池包和用电装置 WO2023207819A1 (zh)

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