Battery management method, device, storage medium, electrical apparatus, battery, and system

Abstract

The present application discloses a battery management method, a device, a storage medium, an electrical apparatus, a battery, and a system. The battery management method comprises: acquiring temperature change data of a change in battery charge, and central wavelength change data of an optical fiber sensor, a change value of battery charge corresponding to the temperature change data being related to a change value of battery charge corresponding to the central wavelength change data; and, according to an impact relationship of the temperature change data on the central wavelength change data, determining expansion force data of the change in battery charge. Thus, the expansion force data of the change in battery charge can be obtained by means of combining the temperature change data with one optical fiber sensor, thus alleviating the problem of high costs caused by multiple optical fiber sensors, and effectively relieving adverse risks such as battery diving, and electrode plate or battery cell rupture, caused by abnormal battery expansion force, and improving the usage safety performance of a battery.

Description

Battery management method, device, storage medium, power device, battery and system

[0001] This application claims priority to Chinese patent application No. 2023115807224, filed on November 24, 2023, entitled “Battery management method, device, storage medium, electrical device, battery and system”, which is incorporated herein by reference in its entirety.

Technical field

[0002] The present application relates to the field of battery technology, and in particular to battery management methods, equipment, storage media, electrical devices, batteries, and systems. [Background Technology]

[0003] Energy conservation and emission reduction are key to sustainable development, which in turn promotes the adjustment of energy structure and drives the development and application of battery technology. The key to the development of battery technology lies in electrochemical energy storage technology. Due to its advantages such as high energy density, good cycle life, high operating voltage, environmental friendliness, and low self-discharge, it has been widely used in portable electronics, electric vehicles, and energy storage systems.

[0004] As the battery ages, its expansion force continues to increase and may exceed the maximum allowable design value, leading to a drop in capacity and rupture of the electrodes or cells. Therefore, by determining the change in expansion force, targeted measures can be taken. In existing related technologies, two fiber optic sensors are integrated into the battery at the same time. The two fiber optic sensors jointly monitor the battery status to obtain the battery's expansion force and temperature. However, fiber optic sensors are difficult to manufacture and difficult to mass-produce. If a large number of fiber optic sensors are integrated into the battery at the same time, the production cost will be greatly increased.

[0005] [Summary of the invention]

[0006] The main purpose of this application is to provide a battery management method, equipment, storage medium, power device, battery and system, aiming to solve the above-mentioned technical problems existing in the prior art.

[0007] To address the aforementioned issues, the present application provides a battery management method, comprising: obtaining temperature variation data of a battery's charge change and center wavelength variation data from an optical fiber sensor, wherein the battery's charge change value corresponding to the temperature variation data is correlated with the battery's charge change value corresponding to the center wavelength variation data; and determining battery expansion force data associated with the charge change based on the relationship between the temperature variation data and the center wavelength variation data. Thus, battery expansion force data associated with the charge change can be obtained using a single optical fiber sensor combined with the temperature variation data, alleviating the high cost associated with multiple optical fiber sensors. Furthermore, the correlation between the battery charge change value corresponding to the temperature variation data and the battery charge change value corresponding to the center wavelength variation data makes the resulting expansion force data more accurate, effectively mitigating adverse risks such as battery water leakage, electrode or cell rupture, and so on, caused by abnormal battery expansion force, thereby improving battery safety.

[0008] In some embodiments, the step of determining battery charge change expansion force data based on the relationship between temperature change data and center wavelength change data includes: obtaining a temperature influence coefficient and a stress sensitivity coefficient of the optical fiber sensor; and determining the battery charge change expansion force data based on the temperature influence coefficient, the stress sensitivity coefficient, the temperature change data, and the center wavelength change data. Thus, by simultaneously considering the effects of the temperature influence coefficient and the stress sensitivity coefficient on the center wavelength, more accurate battery charge change expansion force data can be obtained.

[0009] In some embodiments, the step of determining battery charge-dependent expansion force data based on the temperature influence coefficient, stress sensitivity coefficient, temperature variation data, and center wavelength variation data includes: subtracting the center wavelength variation data from the product of the temperature influence coefficient and the temperature variation data to obtain a difference; and multiplying the difference by the stress sensitivity coefficient to obtain the battery charge-dependent expansion force data. Thus, by calculating the temperature influence coefficient, stress sensitivity coefficient, temperature variation data, and center wavelength variation data, more accurate battery charge-dependent expansion force data can be obtained in a simple manner.

[0010] In some embodiments, the step of obtaining temperature variation data associated with a battery charge variation includes: determining a first charge value and a second charge value associated with the battery charge variation; determining a first battery temperature at the first charge value and a second battery temperature at the second charge value; and obtaining temperature variation data based on the first battery temperature and the second battery temperature. Thus, by determining the first battery temperature corresponding to the first charge value and the second battery temperature corresponding to the second charge value, more accurate temperature variation data associated with the battery charge variation can be obtained, facilitating the acquisition of more accurate expansion force data.

[0011] In some embodiments, the step of determining a first battery temperature at a first charge value and a second battery temperature at a second charge value includes: obtaining a first ambient temperature corresponding to the first charge value and a second ambient temperature corresponding to the second charge value; obtaining the first battery temperature based on the first charge value, the first ambient temperature, and a battery temperature variation equation; and obtaining the second battery temperature based on the second charge value, the second ambient temperature, and the temperature variation equation. Thus, by simultaneously considering the effects of the charge value and ambient temperature on the battery temperature and combining them with the temperature variation equation, the corresponding battery temperature can be more simply and accurately determined, thereby obtaining more accurate expansion force data.

[0012] In some embodiments, the battery management method further includes: obtaining battery charge data, battery temperature data corresponding to the charge data, and ambient temperature data of the battery to obtain multiple sets of temperature fitting data; and fitting the multiple sets of temperature fitting data to obtain a battery temperature variation equation. The temperature variation equation obtained through fitting facilitates combining the ambient temperature and charge value to obtain the corresponding battery temperature, simplifying subsequent battery temperature acquisition and improving the efficiency of confirming expansion force data.

[0013] In some embodiments, the step of obtaining central wavelength change data of the optical fiber sensor during battery charge changes includes: determining a first central wavelength corresponding to a first charge value and a second central wavelength corresponding to a second charge value; and obtaining central wavelength change data based on the first central wavelength and the second central wavelength. Thus, the first temperature and the first central wavelength both correspond to the first charge value, the second temperature and the second central wavelength both correspond to the second charge value, and the central wavelength change data and the temperature change data are both generated when the battery changes between the first charge value and the second charge value. This allows for more accurate determination of the battery's expansion force changes during transitions between the first charge value and the second charge value, effectively mitigating adverse risks such as battery water leakage, electrode or cell rupture, and other risks caused by abnormal battery expansion force, thereby improving battery safety.

[0014] In some embodiments, after determining the battery's expansion force data in response to a charge change based on the relationship between the temperature change data and the center wavelength change data, the battery management method further comprises: obtaining battery health data and the maximum expansion force under charge under the battery health data to obtain multiple sets of expansion force fitting data; fitting the multiple sets of expansion force fitting data to obtain a battery expansion force variation equation; and determining the battery's state of health based on the expansion force variation equation. Thus, by fitting the multiple sets of expansion force fitting data to obtain a battery expansion force variation equation, the battery's state of health can be predicted based on the expansion force variation equation to perform a risk assessment on the battery, thereby facilitating targeted battery management and improving battery safety. The entire method is simple to operate and has low cost.

[0015] In some embodiments, the step of determining the battery's state of health based on the expansion force variation equation includes: determining a predicted expansion force value for a first preset health value based on the expansion force variation equation; comparing the predicted expansion force value with an expansion force threshold corresponding to the first preset health value to obtain a first comparison result; and determining the battery's state of health based on the first comparison result. Thus, the predicted expansion force value for the first preset health value can be obtained using the expansion force variation equation, and the predicted expansion force value can be compared with the expansion force threshold to determine the battery's state of health. This allows for a simple prediction of the battery's state of health, facilitates targeted battery management, and improves battery safety.

[0016] In some embodiments, the step of determining the battery health state based on the first comparison result includes: if the predicted expansion force value is less than or equal to the corresponding expansion force threshold, determining that the battery is in a state where the expansion force is within the limit; and if the predicted expansion force value is greater than the corresponding expansion force threshold, determining that the battery is in a state where the expansion force is exceeded. Thus, the predicted expansion force value is compared with the expansion force threshold. If the predicted expansion force value is greater, the battery is determined to be in a state where the expansion force is exceeded, thus accurately concluding that the battery is in an unhealthy state. If the predicted expansion force value is smaller, the battery is determined to be in a state where the expansion force is within the limit, thus accurately concluding that the battery is in a healthy state. This facilitates targeted battery management and improves battery safety.

[0017] In some embodiments, the step of determining the battery's state of health based on the expansion force variation equation includes: determining the rate of change of the expansion force variation equation at a second preset health value; comparing the rate of change with a preset rate of change threshold to obtain a second comparison result; and determining the battery's lithium deposition state based on the second comparison result. Thus, by determining the rate of change of the expansion force variation equation at the second preset health value and comparing the rate of change with the preset rate of change threshold to determine the battery's lithium deposition state, the battery's lithium deposition state can be predicted in a simple manner, facilitating targeted battery management and improving battery safety.

[0018] In some embodiments, the step of determining the lithium deposition state of the battery based on the second comparison result includes: if the rate of change is less than or equal to a preset rate of change threshold, determining that the battery is in a non-lithium deposition state; if the rate of change is greater than the preset rate of change threshold, determining that the battery is in a lithium deposition state. Thus, the rate of change is compared with the preset rate of change threshold. When the rate of change is greater, it is determined that the battery is in a lithium deposition state, i.e., accurately concluding that the battery is in an unhealthy state. When the rate of change is smaller, it is determined that the battery is in a non-lithium deposition state, i.e., accurately concluding that the battery is in a healthy state. This facilitates targeted battery management and improves battery safety.

[0019] To solve the above problems, the present application provides a battery management device, which includes a processor and a memory. The memory stores a computer program, and the processor is used to execute the computer program to implement the above battery management method.

[0020] To solve the above problems, the present application provides a computer-readable storage medium having program instructions stored thereon, which implement the above battery management method when the program instructions are executed by a processor.

[0021] To solve the above problems, the present application provides a battery system, which includes a battery cell, an optical fiber sensor, a temperature detection element and a battery management device. The temperature detection element is used to detect the temperature of the battery cell, and the battery management device is used to execute the above battery management method.

[0022] To address the above-mentioned issues, the present application provides a battery comprising: a temperature detection element for detecting battery temperature; an optical fiber sensor capable of changing its center wavelength in response to temperature and stress; and a battery management device connected to the temperature detection element and the optical fiber sensor, respectively. The battery management device is configured to determine temperature variation data of the battery charge change based on the battery temperature detected by the temperature detection element. The battery management device is further configured to determine expansion force data associated with the battery charge change based on the relationship between the temperature variation data and the center wavelength variation data. The battery charge variation value corresponding to the temperature variation data is correlated with the battery charge variation value corresponding to the center wavelength variation data. Thus, expansion force data associated with the battery charge change can be obtained using a single optical fiber sensor in combination with the temperature variation data, alleviating the high cost associated with multiple optical fiber sensors. Furthermore, the correlation between the battery charge variation value corresponding to the temperature variation data and the center wavelength variation data makes the obtained expansion force data more accurate, effectively mitigating adverse risks such as battery water leakage, electrode or cell rupture, and so on, caused by abnormal battery expansion force. This improves the safety of the battery.

[0023] In some embodiments, the battery includes a housing, and the optical fiber sensor and the temperature sensing element are adjacently positioned within the housing. Thus, positioning the optical fiber sensor and the temperature sensing element adjacently allows the temperature detected by the sensing element and the temperature affecting the optical fiber sensor to be kept as consistent as possible, thereby enabling more accurate expansion force data to be obtained as the battery charges.

[0024] In some embodiments, the battery includes a housing and an electrode assembly disposed within the housing, and the temperature sensing element is connected to the electrode assembly. Thus, by connecting the temperature sensing element to the electrode assembly, the temperature detected by the temperature sensing element can be closer to the actual temperature of the battery, thereby obtaining more accurate expansion force data.

[0025] In some embodiments, the electrode assembly is provided with a temperature sensing element, or the temperature sensing element is provided on the outer surface of the electrode assembly. Thus, the electrode assembly encapsulating the temperature sensing element can make the temperature detected by the temperature sensing element closer to the actual temperature of the battery. By providing the temperature sensing element on the outer surface of the electrode assembly, it is easier to embed the temperature sensing element into the housing, thereby improving production efficiency and reducing production costs.

[0026] In some embodiments, the battery further includes an optical demodulator, which is communicatively coupled to the battery management device and configured to transmit light to the fiber optic sensor and receive light transmitted back from the fiber optic sensor. Thus, the optical demodulator can demodulate the light and convert the optical signal into an electrical signal, allowing the battery management device to obtain expansion force data based on the relevant data.

[0027] In order to solve the above problems, the present application provides an electrical device, which includes the above-mentioned battery.

Brief Description of the Drawings

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] FIG1 is a schematic structural diagram of a vehicle according to one or more embodiments;

[0030] FIG2 is a schematic diagram of an exploded structure of a battery pack according to one or more embodiments;

[0031] FIG3 is a schematic diagram of a disassembled structure of a battery according to one or more embodiments;

[0032] FIG4 is a schematic diagram showing a change in the central wavelength of an optical fiber sensor according to one or more embodiments;

[0033] FIG5 is a schematic block diagram of a battery according to one or more embodiments;

[0034] 6 is a schematic structural diagram of an optical fiber sensor, a temperature detection element, and an electrode assembly according to one or more embodiments;

[0035] FIG7 is a flow chart of a battery management method according to one or more embodiments;

[0036] FIG8 is a schematic diagram of a process for obtaining temperature change data according to one or more embodiments;

[0037] FIG9 is a schematic diagram of the flow chart after step S702 in the battery management method shown in FIG7 ;

[0038] FIG10 is a schematic diagram of a structure according to one embodiment of one or more battery systems;

[0039] FIG11 is a schematic diagram of the structure of one or more battery management devices according to an embodiment;

[0040] FIG12 is a block diagram of an embodiment of a computer storage medium according to one or more embodiments. [Specific implementation method]

[0041] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0043] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0044] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0045] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0046] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0047] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0048] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0049] Currently, market developments indicate that batteries are increasingly being used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As battery applications continue to expand, market demand is also growing.

[0050] Batteries mentioned in this field can be categorized as either primary batteries or rechargeable batteries, depending on whether they are rechargeable. Primary batteries are also called "disposable" batteries or primary batteries because once they are depleted, they cannot be recharged and must be discarded. Rechargeable batteries are also called secondary batteries, secondary batteries, or storage batteries. Rechargeable batteries are manufactured using different materials and processes than primary batteries. Their advantage is that they can be reused multiple times after charging, and their output current capacity is higher than that of most primary batteries. Common types of rechargeable batteries include lead-acid batteries, nickel-metal hydride batteries, and lithium-ion batteries. Lithium-ion batteries offer advantages such as light weight, high capacity (1.5 to 2 times that of nickel-metal hydride batteries of the same weight), no memory effect, and a very low self-discharge rate. Consequently, despite their relatively high price, they are widely used. Lithium-ion batteries are also widely used in pure electric vehicles and hybrid vehicles. While the capacity of lithium-ion batteries used for these applications is relatively low, they offer high output, high charging current, and a long service life, albeit at a higher cost.

[0051] The batteries described in the embodiments of this application are either rechargeable batteries or disposable batteries. The embodiments disclosed herein will be described primarily using lithium-ion batteries as an example. It should be understood that the embodiments disclosed herein are applicable to any other suitable type of rechargeable battery. The batteries described in the embodiments disclosed herein can be directly or indirectly used in appropriate devices to power such devices.

[0052] The present application provides an electrical device, which may include but is not limited to mobile phones, tablets, laptops, electric toys, electric tools, battery-powered vehicles, electric cars, ships, spacecraft, and the like. The electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the spacecraft may include airplanes, rockets, space shuttles, and spacecraft. The electrical device may include a battery, which may provide electrical energy to the device to achieve corresponding functions.

[0053] The present application also provides an electric vehicle, which may include a battery pack.

[0054] Please refer to FIG. 1 , which is a schematic structural diagram of a vehicle according to one or more embodiments.

[0055] Vehicle 1 can be a fuel-powered vehicle, a gas-powered vehicle, or a new energy vehicle. The latter can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle. Vehicle 1 is internally equipped with a battery pack 2, which can be located at the bottom, front, or rear of vehicle 1. Battery pack 2 can be used to power vehicle 1, for example, as an operating power source for vehicle 1. Vehicle 1 also includes a controller 3 and a motor 4. Controller 3 controls battery pack 2 to power motor 4, for example, to meet the power requirements of vehicle 1 during startup, navigation, and driving.

[0056] In some embodiments of the present application, the battery pack 2 can serve not only as the operating power source of the vehicle 1, but also as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0057] In order to improve the performance of electrical devices, the present application also provides a battery pack. See FIG2 , which is a schematic diagram of the exploded structure of a battery pack according to one or more embodiments.

[0058] The shape of the battery pack may include but is not limited to a square, cylindrical, or other arbitrary shapes.

[0059] In some embodiments, the battery pack 2 may include a case 20 and a battery 10, with the battery 10 contained within the case 20. The case 20 is used to provide a storage space for the battery 10, and the case 20 may adopt a variety of structures. In some embodiments, the case 20 may include a first portion 21 and a second portion 22, the first portion 21 and the second portion 22 covering each other, and the first portion 21 and the second portion 22 jointly defining a storage space for accommodating the battery 10. The second portion 22 may be a hollow structure with one end open, and the first portion 21 may be a plate-like structure, with the first portion 21 covering the open side of the second portion 22, so that the first portion 21 and the second portion 22 jointly define a storage space; the first portion 21 and the second portion 22 may also be hollow structures both with one side open, with the open side of the first portion 21 covering the open side of the second portion 22.

[0060] The battery 10 may include battery cells. Within the battery pack 2, there may be multiple battery cells, which may be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections. Multiple battery cells may be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure of the multiple battery cells is housed within the housing 20. Alternatively, the battery pack 2 may comprise multiple battery cells connected in series, in parallel, or in a hybrid configuration to form a battery module, which is then connected in series, in parallel, or in a hybrid configuration to form a single unit housed within the housing 20. The battery pack 2 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells.

[0061] Battery cell production methods include laminated and wound methods. Laminated batteries offer uniform current collection, low internal resistance, and high specific power. However, to achieve high precision, they require extremely high mold accuracy, high equipment investment, and a complex process, resulting in low production efficiency. Wound batteries are simple to produce, with moderate equipment precision requirements during the production and assembly processes. They offer high production efficiency and low costs. In terms of performance, wound batteries offer excellent high and low temperature resistance, rapid charging, an extremely long lifespan, stable high output voltage, a sturdy structure, and strong shock resistance.

[0062] The battery 10 may also include battery cells and other functional components. For example, the battery 10 may also include a control chip and / or a sensor, etc.

[0063] In a related embodiment, the expansion force of the battery 10 increases continuously during the aging process and may exceed the maximum value allowed by the design, thereby causing a capacity drop or a rupture of the electrode or battery cell. Therefore, by determining the change in the expansion force, relevant measures can be taken in a targeted manner. In the existing related technology, two fiber optic sensors are integrated into the battery at the same time. The two fiber optic sensors jointly monitor the status of the battery to obtain the battery's expansion force and temperature. However, the manufacturing of fiber optic sensors is difficult and difficult to mass produce. If a large number of fiber optic sensors are integrated into the battery at the same time, the production cost will be greatly increased.

[0064] The present application also provides a battery. See FIG3 , which is a schematic diagram of the disassembled structure of a battery according to one or more embodiments.

[0065] The battery 10 may include an outer shell 100, which may be formed with a space for accommodating bare cells and other functional components. Specifically, the outer shell 100 may include end caps and a shell. The end caps refer to components that cover the opening of the shell to isolate the internal environment of the shell from the external environment. Without limitation, the shape of the end caps can be adapted to the shape of the shell to match the shell. Optionally, the end caps can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end caps are less likely to deform when squeezed or collided, so that the battery cell can have higher structural strength and improved safety performance. Functional components such as electrode terminals may be provided on the end caps. The electrode terminals can be used to electrically connect to the bare cells for outputting or inputting electrical energy from the battery 10. In some embodiments, the electrode terminals may include poles. The poles may include positive poles and negative poles for outputting current and connecting to external circuits. In some embodiments, the end caps may also be provided with explosion-proof parts for releasing internal pressure when the internal pressure or temperature of the battery cell reaches a threshold. The end cap can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic, and this is not particularly limited in the present embodiment. In some embodiments, an insulating member can be provided on the inner side of the end cap to isolate the electrical connection components within the housing from the end cap to reduce the risk of short circuits. Exemplary insulating members can be plastic, rubber, and the like.

[0066] The shell is a component used to cooperate with the end cap to form the internal environment of the battery cell, wherein the formed internal environment can be used to accommodate bare cells, electrolytes and other components. The shell and the end cap can be independent components, and an opening can be set on the shell, and the internal environment of the battery cell is formed by covering the opening with the end cap at the opening. Without limitation, the end cap and the shell can also be integrated. Specifically, the end cap and the shell can form a common connection surface before other components are put into the shell, and when the interior of the shell needs to be encapsulated, the end cap is covered with the shell. The shell can be of various shapes and sizes, such as rectangular, cylindrical, hexagonal, etc. Specifically, the shape of the shell can be determined according to the specific shape and size of the electrode assembly. The material of the shell can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose special restrictions on this.

[0067] In order to solve the technical problems existing in the relevant embodiments, the battery 10 also includes a temperature detection element 200, an optical fiber sensor 300 and a battery management device 400. The temperature detection element 200 can be used to detect temperature, and the optical fiber sensor 300 can change its own central wavelength under temperature and stress. The battery management device 400 can collect the temperature detected by the temperature detection element 200, as well as relevant data on the change of the central wavelength of the optical fiber sensor 300, etc.

[0068] The temperature detection element 200 and the optical fiber sensor 300 can be set at any position inside the housing 100. For example, the temperature detection element 200 and the optical fiber sensor 300 are both set on the inner wall of the housing 100, or on the end cover, or on other functional components such as the bare battery cell.

[0069] The temperature sensing element 200 can be electrically connected to the terminal of the battery 10 to enable the temperature sensing element 200 to perform its corresponding function. The temperature sensing element 200 can detect the temperature inside the housing 100, and further infer the current operating temperature of the battery 10, so as to adjust the operating state of the battery 10 according to the current operating temperature of the battery 10.

[0070] The optical fiber sensor 300 may include, but is not limited to, a Bragg grating optical fiber sensor (FBG), a reflective volume Bragg grating optical fiber sensor (RBG), a transmissive volume Bragg grating optical fiber sensor (TBG), and the like. Taking the optical fiber sensor 300 as an example of a Bragg grating optical fiber sensor (FBG), the basic principle of the Bragg grating optical fiber sensor 300 is to create a grating region with a periodic refractive index distribution at a specific location on the optical fiber. Light waves of a specific wavelength will be reflected within this region, wherein the length of the grating region can be between 0.5 cm and 1 cm. The reflected center wavelength signal is related to the grating period and the effective refractive index of the fiber core. When the grating region is used as a sensing region, when the temperature, structure, or position of the sensed material changes, the period of the grating or the effective refractive index of the core membrane will change, thereby changing the center wavelength of the optical fiber sensor 300.

[0071] The optical fiber sensor 300 may include a cladding and a core. The cladding is coated on the outside of the core. The radial dimension of the cladding may be less than or equal to 125 μm. For example, the radial dimension of the cladding may be 50 μm, 40 μm, 30 μm, 60 μm, 55 μm, 45 μm, etc.

[0072] 4 , which is a schematic diagram of a central wavelength change of an optical fiber sensor according to one or more embodiments.

[0073] As shown in FIG4 , the horizontal axis represents the central wavelength of the optical fiber sensor 300, and the vertical axis represents the light intensity of the light irradiated to the optical fiber sensor 300. The initial central wavelength of the optical fiber sensor 300 is λ1. When the optical fiber sensor 300 is affected by external factors, its central wavelength will change accordingly. For example, when the optical fiber sensor 300 is affected by temperature and / or stress, its central wavelength will change from λ1 to λ2. At this time, the change in the central wavelength of the optical fiber sensor 300 is the difference between λ1 and λ2.

[0074] The battery management device 400 is connected to the temperature detection element 200 and the optical fiber sensor 300 respectively. The battery management device 400 can be located inside or outside the housing 100. The battery management device 400 can be a battery management system (BMS), or a battery management unit (BMU) of a battery management system, or a controller such as a central control platform of a vehicle or energy storage system. One battery management device 400 can act on multiple battery cells at the same time. The battery management device 400 can be connected to the temperature detection element 200 and the optical fiber sensor 300 for communication. For example, the battery management device 400 can be directly connected to the temperature detection element 200 and the optical fiber sensor 300 for wired communication, or the temperature detection element 200 and the optical fiber sensor 300 can be connected to other devices, and the battery management device 400 can then be connected to the other devices for wired or wireless communication, etc. Among them, wireless communication can include Bluetooth communication, radio frequency communication, or optical communication, etc.

[0075] The battery management device 400 is configured to determine temperature variation data related to battery charge changes based on the battery temperature detected by the temperature detection element 200. The battery management device 400 is also configured to determine expansion force data related to battery charge changes based on the relationship between the temperature variation data and the center wavelength variation data. The optical fiber sensor 300 is located within the housing 100. Factors that significantly affect the center wavelength of the optical fiber sensor 300 include changes in battery temperature and battery stress. These changes are primarily caused by the battery 10's expansion after use. By obtaining the battery temperature detected by the temperature detection element 200 and the center wavelength variation of the optical fiber sensor 300, the battery management device 400 can remove the effect of the battery temperature on the center wavelength variation of the optical fiber sensor 300, thereby determining the relationship between the center wavelength variation of the optical fiber sensor 300 and the expansion force of the battery 10, and thereby obtaining the battery 10 expansion force data. The battery charge variation value corresponding to the temperature variation data is correlated with the battery charge variation value corresponding to the center wavelength variation data. Specifically, the charge change values ​​of the batteries corresponding to the two data sets can be the same or similar. For example, the temperature change data is the difference between the battery's temperature at a first charge value and the battery's temperature at a second charge value, and the center wavelength change data is the difference between the center wavelength of the optical fiber sensor at the first charge value and the center wavelength of the optical fiber sensor at the second charge value. Both of these collected data sets correspond to the first charge value and the second charge value of the battery, meaning that the corresponding battery charge change values ​​are the same and correlated.

[0076] Through the above-mentioned embodiment, a single optical fiber sensor 300 can be used in combination with temperature change data to obtain expansion force data of the charge change of the battery 10, thereby alleviating the high cost problem caused by multiple optical fiber sensors 300, and can also effectively alleviate adverse risks such as battery 10 diving, pole piece or battery cell rupture due to abnormal expansion force of the battery 10, thereby improving the safety performance of the battery 10.

[0077] Referring to FIG. 5 , FIG. 5 is a schematic block diagram of a battery according to one or more embodiments.

[0078] Battery 10 also includes an optical demodulator 500, which is communicatively connected to battery management device 400. The optical demodulator 500 is configured to emit light to the fiber optic sensor 300 and receive light transmitted back from the fiber optic sensor 300. The optical demodulator 500 can convert optical signals collected by the fiber optic sensor 300 into electrical signals for collection and processing by the battery management device 400. For example, the optical demodulator 500 may include a light source, a photodetection unit, and a signal processing unit. The light source can emit signal light to the fiber optic sensor 300, which is then transmitted to the grating region of the fiber optic sensor 300. The grating region reflects a portion of the signal light to the photodetection unit of the optical demodulator 500. The photodetection unit converts the reflected signal light into an electrical signal, which is then processed by the signal processing unit and transmitted to the battery management device 400. Thus, the optical demodulator 500 can demodulate the light and convert the optical signal into an electrical signal, allowing the battery management device 400 to obtain expansion force data based on the relevant data.

[0079] The optical fiber sensor 300 and the temperature detection element 200 are disposed adjacent to each other. The adjacent arrangement of the optical fiber sensor 300 and the temperature detection element 200 can be understood as follows: the optical fiber sensor 300 and the temperature detection element 200 are located at the same position inside the housing 100. At this position, the temperature effect on the optical fiber sensor 300 and the temperature detection element 200 are substantially the same. For example, the optical fiber sensor 300 and the temperature detection element 200 are both fixed to the inner wall surface of the housing 100, or both are fixed to the same position of the electrode assembly 600. Therefore, by arranging the optical fiber sensor 300 and the temperature detection element 200 adjacent to each other, the temperature detected by the detection element and the temperature affecting the optical fiber sensor 300 can be kept as consistent as possible, thereby obtaining more accurate expansion force data during charge changes of the battery 10.

[0080] 6 , which is a schematic structural diagram of an optical fiber sensor, a temperature detection element, and an electrode assembly according to one or more embodiments.

[0081] The battery 10 includes an electrode assembly 600 disposed in the outer casing 100, and the temperature detection element 200 is connected to the electrode assembly 600. The electrode assembly 600 is a component in the battery 10 where electrochemical reactions occur. The outer casing 100 may contain one or more electrode assemblies 600. The electrode assembly 600 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and an isolator is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly 600, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a tab. The positive electrode tab and the negative electrode tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery 10, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop. As a crucial component of the battery 10, the electrode assembly 600 is susceptible to high temperatures and significant stress concentration in certain locations after prolonged use. This can lead to difficulties with electrolyte infiltration, cycling water dropouts, and even risks such as lithium deposition and electrode fracture. Therefore, by connecting the temperature sensing element 200 and the optical fiber sensor 300 to the electrode assembly 600, the temperature detected by the temperature sensing element 200 can be closer to the actual temperature of the battery 10, enabling more accurate expansion force data to be obtained.

[0082] Optionally, the electrode assembly 600 is provided to cover the temperature detection element 200, or the temperature detection element 200 is provided on the outer surface of the electrode assembly 600. The electrode assembly 600 may be wound or stacked. For example, when the electrode assembly 600 is wound, the temperature detection element 200 may be located at the initial winding position of the electrode assembly 600, or at the middle position of the winding of the electrode assembly 600, or at the outer surface of the electrode assembly 600. For example, when the electrode assembly 600 is stacked, the temperature detection element 200 may be located inside or on the outer surface of the electrode assembly 600. Specifically, the temperature detection element 200 may be located on the surface of the larger surface of the electrode assembly 600 or at the side corner. Thus, the electrode assembly 600 covers the temperature detection element 200, which can make the temperature detected by the temperature detection element 200 closer to the actual temperature of the battery 10. By arranging the temperature detection element 200 on the outer surface of the electrode assembly 600 , it is easier to implant the temperature detection element 200 into the housing 100 , thereby improving production efficiency and reducing production costs.

[0083] To address the technical issues in the related embodiments, this application provides a battery management method, which can be applied to the batteries of any of the above embodiments. Referring to FIG7 , FIG7 is a flowchart of the battery management method according to one or more embodiments. Specifically, the method includes the following steps S701 to S702.

[0084] Step S701: Acquire temperature variation data of battery charge variation and central wavelength variation data of the optical fiber sensor.

[0085] Battery SOC, or state of charge, reflects the remaining capacity of a battery. Its numerical value is defined as a ratio of the battery capacity and is often expressed as a percentage. For example, 100% SOC indicates a fully charged battery, while 0% SOC indicates a fully discharged battery. During the charging or discharging process, the battery's SOC changes, meaning the battery undergoes a charge change. The battery's internal temperature and expansion force also change with charge. For example, during continuous charging, the internal temperature of the battery increases. When a battery changes from one charge value to another, the change in battery temperature can be interpreted as temperature change data, and the change in the center wavelength of a fiber optic sensor can be interpreted as center wavelength change data. For example, when a battery is charged from 0% SOC to 100% SOC, the change in battery temperature from 0% SOC to 100% SOC is the battery's temperature change value, and the change in center wavelength from 0% SOC to 100% SOC is the center wavelength change value of the fiber optic sensor. The battery charge change value corresponding to the temperature change data is correlated with the battery charge change value corresponding to the center wavelength change data. Specifically, the battery charge change values ​​corresponding to the two data may be the same or similar. For example, the temperature change data is the difference between the battery temperature at a first charge value and the battery temperature at a second charge value, and the center wavelength change data is the difference between the center wavelength of the optical fiber sensor at the first charge value and the center wavelength of the second charge value. Both of the collected data correspond to the first charge value and the second charge value of the battery, that is, the battery charge change values ​​corresponding to the two data are the same and correlated.

[0086] Step S702: Determine the expansion force data of the battery charge change according to the influence relationship between the temperature change data and the center wavelength change data.

[0087] Factors that significantly influence the center wavelength of a fiber optic sensor include changes in battery temperature and battery stress. These changes occur primarily during the battery's charging and discharging process, while changes in battery stress are primarily caused by the battery's expansion after use. By obtaining the battery temperature detected by the temperature sensing element and the changes in the center wavelength of the fiber optic sensor, the effect of the battery temperature on the center wavelength of the fiber optic sensor can be removed based on the relationship between the temperature change data and the center wavelength change data, thereby obtaining data on the expansion force caused by the battery charge change. The relationship between the temperature change data and the center wavelength change data varies for different fiber optic sensors, and the specific relationship can be obtained through experiments.

[0088] Through the above-mentioned implementation, the expansion force data of the battery charge change can be obtained by using a single optical fiber sensor in combination with temperature change data, thereby alleviating the high cost problem caused by multiple optical fiber sensors. It can also effectively alleviate the adverse risks such as battery diving, electrode or battery cell rupture caused by abnormal battery expansion force, and improve the safety performance of battery use.

[0089] Specifically, the step of determining battery charge change expansion force data (step S702) based on the influence of temperature change data on center wavelength change data includes: obtaining the temperature influence coefficient and stress sensitivity coefficient of the optical fiber sensor; and determining the battery charge change expansion force data based on the temperature influence coefficient, stress sensitivity coefficient, temperature change data, and center wavelength change data. Both the temperature influence coefficient and stress sensitivity coefficient can be obtained experimentally. The battery charge change expansion force data can be calculated based on the relationship between the temperature influence coefficient and temperature change data, and the relationship between the stress sensitivity coefficient and center wavelength change data. Thus, by simultaneously considering the influence of the temperature influence coefficient and stress sensitivity coefficient on the center wavelength, more accurate battery charge change expansion force data can be obtained.

[0090] Optionally, based on the temperature influence coefficient, the stress sensitivity coefficient, the temperature change data and the center wavelength change data, the step of determining the expansion force data of the battery charge change includes: subtracting the center wavelength change data and the product of the temperature influence coefficient and the temperature change data to obtain a difference; multiplying the difference by the stress sensitivity coefficient to obtain the expansion force data of the battery charge change.

[0091] Specifically, the expansion force data can be calculated using the following formula: F = a*(δλ-b*δT)

[0092] Where F represents the expansion force data, a represents the stress sensitivity coefficient, b represents the temperature influence coefficient, δλ represents the central wavelength change data, and δT represents the temperature change data.

[0093] Therefore, by calculating the temperature influence coefficient, the stress sensitivity coefficient, the temperature change data and the center wavelength change data, more accurate expansion force data during battery charge change can be obtained in a simple manner.

[0094] 8 , which is a schematic diagram of a process for obtaining temperature change data according to one or more embodiments, specifically, the process includes the following steps S801 to S803 .

[0095] Step S801: Determine a first charge value and a second charge value of a battery charge change.

[0096] The first state-of-charge (SOC) and the second state-of-charge (SOC) are different. During the battery's charge and discharge processes, the battery's SOC changes. For example, during charging, the battery's SOC gradually increases, while during discharging, the battery's SOC gradually decreases. The first state-of-charge (SOC) and the second state-of-charge (SOC) can be two different SOCs during a single charge or discharge process. For example, during a single charge, the first state-of-charge (SOC) can be the initial state-of-charge, while the second state-of-charge (SOC) can be the final state-of-charge. For example, the first state-of-charge (SOC) is 0% SOC, and the second state-of-charge (SOC) is 100% SOC.

[0097] Step S802: Determine a first battery temperature at a first charge value and a second battery temperature at a second charge value.

[0098] The temperature detection element can be used to detect the battery temperature in real time during the battery charge change process. For example, during the battery charge change process, the temperature detection element detects the battery temperature once each time the battery charge changes. For example, during the battery charging process, when the battery starts charging, the temperature detection element can detect the battery temperature once, and each time the battery charge value increases by 1% SOC, the temperature detection element detects the battery temperature once. Thus, after determining the first charge value and the second charge value, the first battery temperature corresponding to the first charge value can be determined, and the second battery temperature corresponding to the second charge value can be determined.

[0099] Step S803: Obtaining temperature change data based on the first battery temperature and the second battery temperature.

[0100] The temperature change data can be the difference between the first battery temperature and the second battery temperature. Once the first battery temperature and the second battery temperature are obtained, the difference between the first battery temperature and the second battery temperature can be calculated. Thus, by determining the first battery temperature corresponding to the first charge value and the second battery temperature corresponding to the second charge value, more accurate temperature change data can be obtained during battery charge changes, facilitating the acquisition of more accurate expansion force data.

[0101] Optionally, the step of obtaining the central wavelength change data of the optical fiber sensor of the battery during charge change includes: determining a first central wavelength corresponding to a first charge value and a second central wavelength corresponding to a second charge value; and obtaining the central wavelength change data based on the first central wavelength and the second central wavelength.

[0102] The first battery temperature and the first center wavelength are both obtained when the battery reaches a first charge value, and the second battery temperature and the second center wavelength are both obtained when the battery reaches a second charge value. The temperature change data may be the difference between the first battery temperature and the second battery temperature, and the center wavelength change data may be the difference between the first center wavelength and the second center wavelength. Therefore, the center wavelength change data and the temperature change data are both generated when the battery changes between the first charge value and the second charge value. This allows for more accurate determination of the change in expansion force of the battery as it transitions between the first charge value and the second charge value, effectively mitigating adverse risks such as battery water leakage, electrode or cell rupture, and other risks caused by abnormal battery expansion force, thereby improving battery safety.

[0103] In some embodiments, the step of determining a first battery temperature at a first charge value and a second battery temperature at a second charge value (step S802) includes: obtaining a first ambient temperature corresponding to the first charge value and a second ambient temperature corresponding to the second charge value; obtaining the first battery temperature based on the first charge value, the first ambient temperature and a temperature change equation of the battery; and obtaining the second battery temperature based on the second charge value, the second ambient temperature and the temperature change equation.

[0104] The temperature change equation can be obtained in advance through fitting. The independent variables of the temperature change equation may include ambient temperature and battery charge value. Once the ambient temperature and charge value are obtained, the corresponding ambient temperature and charge value are substituted into the temperature change equation to obtain the corresponding battery temperature. The charge value and ambient temperature can be obtained through battery management equipment. The ambient temperature can be understood as the external temperature of the battery. For example, when there are multiple batteries in a battery pack, the temperature at different locations in the battery pack is different, and the ambient temperature of the batteries at different locations is also different. Generally, the ambient temperature of the battery located in the middle is higher than the ambient temperature of the battery located at the edge. The ambient temperature will directly affect the battery temperature. Considering the impact of the charge value and ambient temperature on the battery temperature, combined with the temperature change equation, the corresponding battery temperature can be obtained more simply and accurately, thereby obtaining more accurate expansion force data.

[0105] Optionally, the battery management method further includes: acquiring battery charge data, battery temperature data corresponding to the charge data, and ambient temperature data of the battery to obtain multiple sets of temperature fitting data; fitting the multiple sets of temperature fitting data to obtain a temperature change equation of the battery.

[0106] Charge data and the battery's ambient temperature can be collected by battery management equipment, and battery temperature data can be detected by a temperature detection element. During the battery's charge and discharge process, each time the battery's charge data is acquired, the battery temperature corresponding to the current charge data and the battery's ambient temperature can be acquired to form a set of temperature fitting data. This step can be repeated to obtain multiple sets of temperature fitting data. For example, during the battery's charge and discharge process, when the acquired charge data reaches 20% SOC, the ambient temperature and battery temperature corresponding to 20% SOC can be acquired, thereby forming a set of temperature change data at 20% SOC; when the acquired charge data reaches 21% SOC, the ambient temperature and battery temperature corresponding to 21% SOC can be acquired, thereby forming a set of temperature fitting data at 21% SOC. Multiple sets of temperature fitting data are continuously acquired in this manner to obtain a temperature fitting database. The multiple sets of temperature fitting data are then fitted to obtain a temperature change equation with ambient temperature and charge as independent variables and battery temperature as the dependent variable. Thus, the temperature variation equation obtained through fitting facilitates the calculation of the corresponding battery temperature by combining the ambient temperature and the charge value, simplifying the subsequent acquisition of the battery temperature and improving the efficiency of confirming the expansion force data. In other embodiments, the temperature variation equation may also include the charging strategy and the position of the temperature sensing element within the battery as dependent variables. The method for fitting the temperature variation equation is similar to that described above and will not be further described here.

[0107] Referring to Figure 9, Figure 9 is a schematic diagram of the flow chart after step S702 in the battery management method shown in Figure 7. Specifically, the method includes the following steps S901 to S903.

[0108] Step S901: obtaining battery health data of a battery and a maximum expansion force of a charge change under the battery health data, and obtaining multiple sets of expansion force fitting data.

[0109] Battery health data can be collected through battery management equipment. Battery health data (SOH) reflects the battery's health, i.e., the percentage of a battery's fully charged capacity relative to its rated capacity. For example, a new battery has a SOH of 100%, while a completely scrapped battery has a SOH of 0%. After long-term use, the battery's health gradually deteriorates. This deterioration in battery health affects the battery's expansion force at different states of charge. When the battery's health reaches a specific value, charging and discharging can be performed based on that specific value to obtain multiple expansion force data sets based on that specific value. The maximum expansion force value is selected from these multiple expansion force data sets, and the maximum expansion force data for that battery health value and the battery health value are combined as a set of expansion force fitting data. This step is repeated to obtain the maximum expansion force corresponding to different battery health values, thereby obtaining multiple sets of expansion force fitting data sets. Exemplarily, when the battery health is 100% SOH, the battery is charged and discharged, and the expansion force is detected during the charging and discharging process to obtain the expansion force data when the health is 100% SOH, and then the maximum expansion force is selected from the expansion force data to obtain the maximum expansion force corresponding to the health of 100% SOH, and used as a set of expansion force fitting data; by analogy, when the battery health decreases to 99% SOH, the maximum expansion force corresponding to the battery health of 99% SOH is obtained; when the battery health decreases to (100-n)% SOH, the maximum expansion force corresponding to the health of (100-n)% SOH is obtained, thereby obtaining multiple sets of expansion force fitting data.

[0110] Step S902: Fitting multiple sets of expansion force fitting data to obtain the expansion force variation equation of the battery.

[0111] The multiple sets of expansion force fitting data may include: multiple sets of expansion force fitting data consisting of all battery health states and maximum expansion forces during the process of the battery health decreasing from one battery health state to another. By fitting the multiple sets of expansion force fitting data, an expansion force variation equation can be obtained with battery health as the independent variable and expansion force as the dependent variable. The battery expansion force variation equation can be used to predict the corresponding expansion force of the battery when the battery health reaches a specific value.

[0112] Step S903: Determine the health status of the battery based on the expansion force variation equation.

[0113] The health status of a battery may include, but is not limited to, whether the battery has an excessive expansion force, or whether the battery is in a lithium deposition state, etc. After determining the expansion force variation equation, the expansion force data corresponding to the rest of the battery health, as well as the slopes at different positions in the expansion force variation equation, can be obtained to determine the health status of the battery. Among them, as the battery health changes, the expansion force variation equation can be updated in real time to more accurately judge the health status of the battery. Thus, multiple sets of expansion force fitting data are fitted to obtain the battery's expansion force variation equation, and the battery's health status can be predicted based on the expansion force variation equation to perform a risk assessment on the battery, thereby facilitating targeted management of the battery and improving the safety performance of battery use. The entire method is simple to operate and has a low cost.

[0114] In some embodiments, the step of determining the health state of the battery based on the expansion force change equation (step S903) includes: determining an expansion force prediction value of a first preset health value based on the expansion force change equation; comparing the expansion force prediction value with the expansion force threshold corresponding to the first preset health value to obtain a first comparison result; and determining the health state of the battery based on the first comparison result.

[0115] The first preset health value can be set based on actual conditions, for example, 70% SOH, 80% SOH, and so on. The first preset health value can also be determined based on the current battery health value. For example, if the current battery health value is 80% SOH, the first preset health value can be reduced by a preset decrease value of 1% SOH. That is, if the current battery health value is 80% SOH, the first preset health value is 79% SOH. After determining the first preset health value, the first preset health value can be directly substituted into the expansion force variation equation to obtain the predicted expansion force value corresponding to the first preset health value. The expansion force threshold can be set based on actual conditions. Different battery health levels can correspond to different expansion force thresholds. The expansion force threshold can be the maximum expansion force specification allowed by the corresponding battery health level. By comparing the predicted expansion force value with the corresponding expansion force threshold, the battery health state can be determined. This allows for a simple prediction of the battery health state, facilitating targeted battery management and improving battery safety.

[0116] Optionally, the step of determining the health status of the battery based on the first comparison result includes: if the expansion force prediction value is less than or equal to the corresponding expansion force threshold, determining that the battery is in an expansion force within-limit state; if the expansion force prediction value is greater than the corresponding expansion force threshold, determining that the battery is in an expansion force exceeding-limit state.

[0117] For example, when the first preset state of health is 70% SOH, the corresponding expansion force threshold is F1, and the predicted expansion force value is F2. When F2 is greater than F1, it indicates that the battery's expansion force is within the limit when the battery health is at the first preset state of health. It can be predicted that the battery will be in a healthy state when the battery health drops to the first preset state of health. When F2 is less than F1, it indicates that the battery's expansion force is within the limit when the battery health is at the first preset state of health. It can be predicted that the battery will be in an unhealthy state when the battery health drops to the first preset state of health. This may lead to adverse risks such as battery leakage, electrode or cell rupture, etc. Therefore, the predicted expansion force value is compared with the expansion force threshold. If the predicted expansion force value is greater, it is determined that the battery is in an expansion force exceeding limit, thus accurately concluding that the battery is in an unhealthy state. If the predicted expansion force value is smaller, it is determined that the battery is in a healthy state, thus accurately concluding that the battery is in a healthy state. This facilitates targeted battery management and improves battery safety.

[0118] Optionally, the step of determining the health state of the battery based on the expansion force change equation (step S903) includes: determining the rate of change of the expansion force change equation at a second preset health value; comparing the rate of change with a preset rate of change threshold to obtain a second comparison result; and determining the lithium plating state of the battery based on the second comparison result.

[0119] The rate of change of the expansion force with the battery health can be obtained by differentiating the expansion force change equation. The second preset health value can be equal to the current health value of the battery, and the second preset value can be ≤95% SOH. For example, when the current health value of the battery is 90% SOH, the rate of change of the expansion force change equation at the second preset health value can be obtained by differentiating the expansion force change equation. The preset change rate threshold can be set according to actual conditions, and the preset change rate threshold corresponding to different battery healths may be different. By comparing the change rate with the corresponding preset change rate threshold, it can be determined whether the battery is in a lithium plating state. Therefore, by determining the change rate of the expansion force change equation at the second preset health value and comparing the change rate with the preset change rate threshold, the lithium plating state of the battery is determined, so that the lithium plating state of the battery can be predicted in a simple way, which facilitates targeted management of the battery and improves the safety performance of battery use.

[0120] Optionally, the step of determining the lithium deposition state of the battery based on the second comparison result includes: if the change rate is less than or equal to a preset change rate threshold, determining that the battery is in a non-lithium deposition state; if the change rate is greater than the preset change rate threshold, determining that the battery is in a lithium deposition state.

[0121] Exemplarily, when the second preset health value is 90% SOH, the corresponding rate of change is R1, and the corresponding preset rate of change threshold is R2. When R1 is greater than R2, it indicates that the battery is in a lithium deposition state when the battery health is the second preset health value, and it can be predicted that when the battery health drops to the second preset health value, the battery is in an unhealthy state. When R1 is less than R2, it indicates that the battery is in a non-lithium deposition state when the battery health is the second preset health value, and it can be predicted that when the battery health drops to the second preset health value, the battery is in a healthy state. In some embodiments, an intermediate rate of change threshold may also be included, and the intermediate rate of change threshold is greater than the preset rate of change threshold. When the rate of change is greater than the preset rate of change threshold and less than the intermediate rate of change threshold, the battery is in a mild lithium deposition state; when the rate of change is greater than the intermediate rate of change threshold, the battery is in a severe lithium deposition state. Therefore, the change rate is compared with the preset change rate threshold. When the change rate is large, it is determined that the battery is in a lithium deposition state, that is, it is accurately concluded that the battery is in an unhealthy state. When the change rate is small, it is determined that the battery is in a non-lithium deposition state, that is, it is accurately concluded that the battery is in a healthy state, which facilitates targeted management of the battery and improves the safety performance of battery use.

[0122] In order to solve the technical problems existing in the relevant embodiments, the present application provides a battery system. See Figure 10, which is a structural schematic diagram according to an embodiment of one or more battery systems.

[0123] The battery system 700 includes a battery cell 101 , an optical fiber sensor 300 , a temperature detection element 200 and a battery management device 400 . The temperature detection element 200 is used to detect the temperature of the battery cell 101 . The battery management device 400 is used to execute the battery management method of any of the above embodiments.

[0124] The battery cell 101 may be a battery cell or battery pack, or other energy storage element that requires testing. The optical fiber sensor 300 may include, but is not limited to, a Bragg grating optical fiber sensor (FBG), a reflective volume Bragg grating optical fiber sensor (RBG), a transmissive volume Bragg grating optical fiber sensor (TBG), and the like. The temperature detection element 200 may be used to detect the temperature of the battery cell 101. The battery management device 400 may be a battery management system (BMS), or a battery management unit (BMU) of a battery management system, or a controller such as a central control platform of a vehicle or energy storage system.

[0125] The battery management method of this embodiment can be applied to a battery management device. The battery management device of this application can be a server, a mobile device, or a system comprising a server and a mobile device. Accordingly, the various components of the mobile device, such as the various units, subunits, modules, and submodules, can be all located in the server, all located in the mobile device, or separately located in the server and the mobile device.

[0126] Optionally, the server may be hardware or software. When the server is hardware, it may be implemented as a distributed server cluster consisting of multiple servers, or as a single server. When the server is software, it may be implemented as multiple software programs or software modules, such as software or software modules for providing a distributed server, or as a single software program or software module, without further limitation.

[0127] In order to solve the technical problems existing in the relevant embodiments, the present application provides a battery management device. Refer to Figure 11, which is a structural diagram of an embodiment of one or more battery management devices.

[0128] The battery management device 400 includes a processor 410 and a memory 420 . The memory 420 stores a computer program. The processor 410 is configured to execute the computer program to implement the battery management method of any of the above embodiments.

[0129] Processor 410 may be an integrated circuit chip with signal processing capabilities. Processor 410 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component. A general-purpose processor may be a microprocessor or any conventional processor.

[0130] The battery management method of the above embodiment may be presented in the form of a computer program. The present application proposes a computer storage medium that carries the computer program. Please refer to FIG12 , which is a structural diagram of an embodiment of a computer storage medium according to one or more embodiments.

[0131] The computer storage medium 800 of this embodiment includes a computer program 810 , which can be executed to implement the above-mentioned battery management method.

[0132] The computer storage medium 800 in this embodiment can be a medium that can store program instructions, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, or it can also be a server that stores the program instructions. The server can send the stored program instructions to other devices for execution, or it can also execute the stored program instructions itself.

[0133] In addition, if the above functions are implemented as software functions and sold or used as independent products, they can be stored in a storage medium readable by a mobile terminal. That is, the present application also provides a storage device storing program data, which can be executed to implement the methods of the above embodiments. The storage device can be, for example, a USB flash drive, an optical disk, a server, etc. In other words, the present application can be embodied in the form of a software product, which includes a number of instructions for causing a smart terminal to execute all or part of the steps of the methods described in each embodiment.

[0134] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0135] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (which can be a personal computer, server, network device, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic devices), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and a portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery management method, characterized in that: The battery management method comprises: Acquire temperature variation data of battery charge variation and central wavelength variation data of the optical fiber sensor, wherein the charge variation value of the battery corresponding to the temperature variation data is related to the charge variation value of the battery corresponding to the central wavelength variation data; The expansion force data of the battery charge change is determined according to the influence relationship between the temperature change data and the central wavelength change data.

2. The battery management method according to claim 1, characterized in that: The step of determining the expansion force data of the battery charge change according to the influence relationship between the temperature change data and the center wavelength change data comprises: Obtaining the temperature influence coefficient and stress sensitivity coefficient of the optical fiber sensor; Based on the temperature influence coefficient, the stress sensitivity coefficient, the temperature change data and the center wavelength change data, the expansion force data of the battery charge change is determined.

3. The battery management method according to claim 2, characterized in that: The step of determining the expansion force data of the battery charge change based on the temperature influence coefficient, the stress sensitivity coefficient, the temperature change data and the center wavelength change data comprises: Subtract the center wavelength variation data from the product of the temperature influence coefficient and the temperature variation data to obtain a difference; The difference is multiplied by the stress sensitivity coefficient to obtain the expansion force data of the battery charge change.

4. The battery management method according to claim 1, characterized in that: The step of obtaining temperature change data of battery charge change comprises: Determine a first charge value and a second charge value of the battery charge change; determining a first battery temperature at the first charge value and a second battery temperature at the second charge value; The temperature change data is obtained based on the first battery temperature and the second battery temperature.

5. The battery management method according to claim 4, characterized in that: The step of determining a first battery temperature at the first charge value and a second battery temperature at the second charge value comprises: Acquire a first ambient temperature corresponding to the first charge value and a second ambient temperature corresponding to the second charge value; obtaining the first battery temperature based on the first charge value, the first ambient temperature and a temperature change equation of the battery; The second battery temperature is obtained based on the second charge value, the second ambient temperature and the temperature change equation.

6. The battery management method according to claim 5, characterized in that: The battery management method further comprises: Acquire charge data of the battery, battery temperature data corresponding to the charge data, and ambient temperature data of the battery to obtain multiple sets of temperature fitting data; A plurality of sets of the temperature fitting data are fitted to obtain the temperature variation equation of the battery.

7. The battery management method according to claim 4, characterized in that: The steps of obtaining the central wavelength change data of the optical fiber sensor of the battery during the charge change include: Determining a first central wavelength corresponding to the first charge value and a second central wavelength corresponding to the second charge value; The center wavelength variation data is obtained based on the first center wavelength and the second center wavelength.

8. The battery management method according to any one of claims 1 to 7, characterized in that: After the step of determining the expansion force data of the battery charge change according to the influence relationship between the temperature change data and the center wavelength change data, the battery management method further includes: Acquire battery health data of the battery and a maximum expansion force of charge change under the battery health data to obtain multiple sets of expansion force fitting data; Fitting multiple groups of expansion force fitting data to obtain an expansion force variation equation of the battery; The health state of the battery is determined based on the expansion force variation equation.

9. The battery management method according to claim 8, characterized in that: The step of determining the health state of the battery based on the expansion force variation equation comprises: Determine the expansion force prediction value of the first preset health value based on the expansion force variation equation; Comparing the predicted expansion force value with the expansion force threshold corresponding to the first preset health value to obtain a first comparison result; A state of health of the battery is determined based on the first comparison result.

10. The battery management method according to claim 9, characterized in that: The step of determining the health status of the battery based on the first comparison result comprises: If the predicted expansion force value is less than or equal to the corresponding expansion force threshold, it is determined that the battery is in an expansion force within-limit state; If the predicted expansion force value is greater than the corresponding expansion force threshold, it is determined that the battery is in an expansion force exceeding limit state.

11. The battery management method according to claim 8, characterized in that: The step of determining the health state of the battery based on the expansion force variation equation comprises: Determining a rate of change of the expansion force change equation at a second preset health value; Comparing the change rate with a preset change rate threshold to obtain a second comparison result; The lithium plating state of the battery is determined based on the second comparison result.

12. The battery management method according to claim 11, characterized in that: The step of determining the lithium deposition state of the battery based on the second comparison result comprises: If the change rate is less than or equal to the preset change rate threshold, it is determined that the battery is in a non-lithium deposition state; If the change rate is greater than the preset change rate threshold, it is determined that the battery is in a lithium deposition state.

13. A battery management device, characterized in that: The battery management device comprises a processor and a memory, wherein a computer program is stored in the memory, and the processor is used to execute the computer program to implement the battery management method according to any one of claims 1 to 12.

14. A computer-readable storage medium having program instructions stored thereon, characterized in that: When the program instructions are executed by a processor, the battery management method according to any one of claims 1 to 12 is implemented.

15. A battery system, characterized in that: The battery system includes a battery cell, an optical fiber sensor, a temperature detection element and a battery management device, wherein the temperature detection element is used to detect the temperature of the battery cell, and the battery management device is used to execute the battery management method according to any one of claims 1 to 12.

16. A battery, characterized in that: The battery comprises: A temperature detection element, wherein the temperature detection element is used to detect the battery temperature; A fiber optic sensor capable of changing its central wavelength under temperature and stress; A battery management device is connected to the temperature detection element and the optical fiber sensor respectively, and is used to determine the temperature change data of the battery charge change according to the battery temperature detected by the temperature detection element. The battery management device is also used to determine the expansion force data of the battery charge change according to the influence of the temperature change data on the center wavelength change data; wherein the charge change value of the battery corresponding to the temperature change data is related to the charge change value of the battery corresponding to the center wavelength change data.

17. The battery according to claim 16, characterized in that The battery comprises a housing, and the optical fiber sensor and the temperature detection element are adjacently arranged in the housing.

18. The battery according to claim 16, characterized in that The battery comprises a shell and an electrode assembly arranged in the shell, and the temperature detection element is connected to the electrode assembly.

19. The battery according to claim 18, characterized in that The electrode assembly covers the temperature detection element, or the temperature detection element is arranged on the outer surface of the electrode assembly.

20. The battery according to claim 16, characterized in that The battery further includes an optical demodulator, which is communicatively connected to the battery management device and is used to emit light to the optical fiber sensor and receive light returned by the optical fiber sensor.

21. An electrical device, characterized in that: The electrical device comprises the battery according to any one of claims 16 to 20.

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