Lithium plating evaluation method for battery based on fiber-optic sensor, and device thereof

Abstract

Disclosed in the present application are a lithium plating evaluation method for a battery based on a fiber-optic sensor, and a device thereof, wherein the device comprises a battery, a battery system, and an electrical apparatus. The lithium plating evaluation method comprises: obtaining a first optical signal output by a fiber-optic sensor when a battery is being charged; obtaining a first spectral signal corresponding to the first optical signal, and obtaining a total enveloped area of a cladding region of the first spectral signal when the battery is being charged on the basis of the first spectral signal; obtaining a second spectral envelope area corresponding to internal stress when the battery is being charged; calculating a difference between the total envelope area and the second spectral envelope area, so as to obtain a first spectral envelope area; and determining a lithium plating evaluation result for the battery on the basis of the first spectral envelope area. By means of analysis of a spectral signal, the interference on lithium plating evaluation by the internal stress of a battery can be reduced, the first spectral envelope area corresponding to lithium plating of the battery when the battery is being charged can be quickly obtained, and consequently the lithium plating circumstances inside the battery can be determined.

Description

Battery lithium deposition detection method and equipment based on optical fiber sensor

[0001] This application claims priority to Chinese patent application No. 2023115297768, filed on November 16, 2023, entitled “Battery lithium deposition detection method and device based on optical fiber sensor”, 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 a method and device for detecting battery lithium deposition based on an optical fiber sensor, wherein the device includes a battery, a battery system, and an electrical device. [Background Technology]

[0003] With the improvement of living standards, more and more people are starting to use various batteries (battery packs) in daily life. And the battery inevitably needs to be charged during use, but there may be lithium plating at the negative electrode during the charging process of the battery, especially in low temperature and fast charging scenarios, the risk of lithium plating of the battery will be further increased. Lithium plating at the negative electrode of the battery will deteriorate the performance of the battery, and the dendritic lithium formed by the lithium plating of the battery may puncture the diaphragm inside the battery, causing a short circuit in the battery, thereby leading to the occurrence of safety accidents. Therefore, there is an urgent need for a detection method that can detect the lithium plating situation inside the battery in real time during the battery charging process.

[0004] [Summary of the invention]

[0005] The present application provides a battery lithium deposition detection method, a battery, a battery system and an electrical device based on an optical fiber sensor, aiming to solve the above-mentioned problems.

[0006] The present application provides a battery lithium deposition detection method based on an optical fiber sensor, the battery lithium deposition detection method comprising: obtaining a first optical signal output by an optical fiber sensor during the battery charging process; obtaining a first spectral signal corresponding to the first optical signal, and obtaining the total envelope area of ​​the envelope region of the first spectral signal during the battery charging process based on the first spectral signal; obtaining a second spectral envelope area corresponding to the internal stress of the battery during the charging process; calculating the difference between the total envelope area and the second spectral envelope area to obtain the first spectral envelope area; and determining the battery lithium deposition detection result based on the first spectral envelope area. Thus, by analyzing the spectral signal, the interference of the battery internal stress on the lithium deposition detection can be reduced, and the first spectral envelope area corresponding to the battery lithium deposition during the charging process can be quickly obtained, thereby confirming the lithium deposition situation inside the battery.

[0007] In some embodiments, the step of obtaining a second spectral envelope area corresponding to the internal stress of the battery during charging includes: obtaining the actual internal stress of the battery during charging; and obtaining the second spectral envelope area corresponding to the internal stress of the battery based on the actual internal stress and a mapping relationship; wherein the mapping relationship includes a correspondence between the internal stress of the battery and the envelope area of ​​the spectral signal under the internal stress. Thus, by obtaining the mapping relationship between the internal stress and the envelope area during the battery charging process, the second spectral envelope area corresponding to the internal stress of the battery during charging can be quickly obtained, thereby reducing the interference of the internal stress during charging on the lithium plating detection results.

[0008] In some embodiments, before obtaining the actual internal stress of the battery during charging, the battery lithium deposition detection method further includes: charging the battery at a preset rate, obtaining a second optical signal of the battery during the preset rate charging process; obtaining a second spectral signal corresponding to the second optical signal, and recording the wavelength change and the envelope area change of the cladding region in the second spectral signal; obtaining the stress data of the battery based on the wavelength change in the second spectral signal and the stress analysis matrix of the battery; fitting based on the stress data and the envelope area change to obtain a mapping relationship. Therefore, before performing a charge lithium deposition detection on the battery, the mapping relationship between the internal stress and the envelope area of ​​different batteries can be obtained by charging the battery at a preset rate, thereby improving the accuracy of the battery lithium deposition detection results.

[0009] In some embodiments, the step of obtaining the actual internal stress of the battery during charging includes: obtaining a wavelength change of a first spectral signal; and obtaining the actual internal stress of the battery during charging based on the wavelength change in the first spectral signal and a stress analysis matrix for the battery. Thus, the actual internal stress of the battery during charging can be quickly obtained based on the wavelength change of the first spectral signal and the stress analysis matrix corresponding to the battery, thereby improving the efficiency of detecting lithium deposition in the battery.

[0010] In some embodiments, the step of determining a battery lithium plating detection result based on the first spectral envelope area includes: determining that lithium plating has occurred in the battery in response to the first spectral envelope area being greater than or equal to a corresponding first preset envelope area threshold; and determining that the battery is at risk of lithium plating in response to the first spectral envelope area being less than the corresponding first preset envelope area threshold and greater than or equal to a corresponding second preset envelope area threshold, wherein the second preset envelope area threshold is less than the first preset envelope area threshold. Thus, by comparing the first spectral envelope area corresponding to lithium plating, the first preset envelope area threshold, and the second preset envelope area threshold, it is possible to quickly determine whether lithium plating has occurred in the battery or is at risk of lithium plating, thereby enabling real-time detection of lithium plating conditions within the battery and reducing the risk of safety issues caused by lithium plating within the battery.

[0011] In some embodiments, the step of determining a battery lithium deposition detection result based on the first spectral envelope area includes: normalizing the first spectral envelope area; determining that lithium deposition has occurred in the battery in response to the normalized first spectral envelope area being greater than or equal to a corresponding first preset percentage threshold; and determining that the battery is at risk of lithium deposition in response to the normalized first spectral envelope area being less than the corresponding first preset percentage threshold and greater than or equal to a corresponding second preset percentage threshold, wherein the second preset percentage threshold is less than the first preset percentage threshold. Thus, by normalizing the first spectral envelope area, the problem of difficulty in providing a unified lithium deposition determination threshold due to differences between different optical fiber sensors can be resolved.

[0012] In some embodiments, after determining a battery lithium deposition detection result based on the first spectral envelope area, the battery lithium deposition detection method further includes: adjusting the battery charging strategy in response to lithium deposition occurring or a risk of lithium deposition occurring during charging. Thus, when lithium deposition occurs or a risk of lithium deposition occurs during charging, adjusting the battery charging strategy can reduce the likelihood of battery safety issues.

[0013] In some embodiments, the step of adjusting the battery charging strategy includes: in response to the lithium deposition test result indicating that there is a risk of lithium deposition, reducing the battery's charging current to charge the battery until the lithium deposition test result indicates that there is no lithium deposition risk; in response to the lithium deposition test result indicating that lithium deposition has occurred, stopping charging the battery and reverse-discharging the battery, and reducing the battery's charging current when charging the battery after reverse discharge. Thus, during the battery charging process, when the lithium deposition test result indicates that there is a risk of lithium deposition or lithium deposition has occurred, by reducing the charging current or stopping charging the battery and charging in the reverse direction, the possibility of safety issues occurring in the subsequent charging process of the battery can be reduced, and the charging speed can be accelerated to the maximum extent, thereby avoiding the occurrence of lithium deposition in the subsequent charging process, eliminating lithium deposited in the battery, and reducing the hazards of lithium deposition.

[0014] The present application further provides a battery. The battery includes a battery body, at least one optical fiber sensor, and a control module. The detection portion of the optical fiber sensor is disposed within the battery body, wherein the optical fiber sensor is configured to output an optical signal during the battery charging process, and the control module is connected to the optical fiber sensor. The control module is configured to obtain a first spectral signal corresponding to the optical signal, and based on the first spectral signal, obtain a total envelope area of ​​the envelope region of the first spectral signal of the battery during the charging process; obtain a second spectral envelope area corresponding to the internal stress of the battery during the charging process; calculate the difference between the total envelope area and the second spectral envelope area to obtain a first spectral envelope area; and determine a lithium deposition detection result of the battery based on the first spectral envelope area. Thus, the battery of the present application can obtain an optical signal during the battery charging process by disposing the detection portion of the optical fiber sensor within the battery body. The control module can reduce the interference of the battery's internal stress on the lithium deposition detection by analyzing the spectral signal corresponding to the optical signal, quickly obtain the first spectral envelope area corresponding to the lithium deposition of the battery during the charging process, thereby confirming the lithium deposition situation within the battery and reducing the risk of battery safety issues.

[0015] In some embodiments, the optical fiber sensor includes at least one grating portion and a transmission optical fiber connected to the grating portion, wherein the grating portion is disposed inside the battery body. Thus, the optical fiber sensor can obtain optical signals during battery charging through the grating portion disposed inside the battery.

[0016] In some embodiments, the input and output ends of the transmission fiber are both located outside the battery body, and the intermediate connection between the input and output ends of the transmission fiber is located inside the battery body. Thus, by inputting an initial optical signal at the input end and analyzing the optical signal output from the output end of the transmission fiber, the results of lithium deposition detection inside the battery during charging can be obtained.

[0017] In some embodiments, a reflective layer is disposed within the battery body, the input end of the transmission optical fiber is disposed outside the battery body, and the output end of the transmission optical fiber is disposed within the battery body and abuts the reflective layer. The reflective layer is configured to reflect the initial light signal incident from the input end so that the output light signal is transmitted outward from the input end. Therefore, by disposing the reflective layer within the battery, the output end of the transmission optical fiber need not be led out of the battery, thereby simplifying the battery structure and improving the convenience of battery manufacturing.

[0018] In some embodiments, the transmission optical fiber includes a core and a cladding, and the diameter of the cladding is set to be between 25 μm and 125 μm. Therefore, setting the cladding diameter between 25 μm and 125 μm can reduce the negative impact that the transmission optical fiber may have on the battery while ensuring that the transmission optical fiber has good mechanical properties.

[0019] In some embodiments, the transmission optical fiber includes a core and a cladding, and the diameter of the cladding is set to be between 50 μm and 100 μm. This can further reduce the negative impact that the transmission optical fiber may have on the battery and further improve the mechanical properties of the transmission optical fiber.

[0020] In some embodiments, the length of the grating portion is set to be between 0.3 cm and 1.2 cm. Therefore, setting the length of the grating portion to be between 0.3 cm and 1.2 cm can improve the efficiency and accuracy of acquiring the optical signal and reduce the negative impact that the transmission optical fiber may have on the battery.

[0021] In some embodiments, the length of the grating portion is set to be between 0.5 cm and 1 cm. This can further improve the efficiency and accuracy of acquiring the optical signal and further reduce the negative impact that the transmission optical fiber may have on the battery.

[0022] In some embodiments, the control module includes an optical demodulation module and a battery management module. The optical demodulation module is connected to the optical fiber sensor and is used to modulate the optical signal output by the optical fiber sensor during the battery charging process to obtain a first spectral signal. The battery management module is connected to the optical demodulation module and is used to obtain the total envelope area of ​​the cladding region of the first spectral signal of the battery during the charging process based on the first spectral signal; obtain the second spectral envelope area corresponding to the internal stress of the battery during the charging process; calculate the difference between the total envelope area and the second spectral envelope area to obtain the first spectral envelope area; and determine the battery lithium plating detection result based on the first spectral envelope area. Thus, the optical demodulation module can demodulate the optical signal of the optical fiber sensor to obtain the first spectral signal, and the battery management module can analyze the lithium plating situation inside the battery based on the first spectral signal, reduce the interference of the battery internal stress on the lithium plating detection, and obtain the battery lithium plating detection result, thereby effectively reducing the harm of lithium plating inside the battery and reducing safety accidents caused by battery lithium plating.

[0023] The present application further provides a battery system comprising the aforementioned battery and a charge-discharge control module, the charge-discharge control module being connected to the control module and the battery and configured to adjust the battery's charging strategy in response to lithium deposition or a risk of lithium deposition occurring during charging. Thus, when lithium deposition or a risk of lithium deposition occurs during charging, the charge-discharge control module can adjust the battery's charging strategy, thereby reducing the likelihood of battery safety issues.

[0024] The present application further provides an electrical device, which includes any of the above-mentioned battery systems.

[0025] Different from the existing technology, the battery lithium deposition detection method of the present application can reduce the interference of the internal stress of the battery on the lithium deposition detection by analyzing the spectral signal, quickly obtain the first spectral envelope area corresponding to the battery lithium deposition during the charging process, and confirm the lithium deposition situation inside the battery, thereby effectively reducing the hazards of lithium deposition inside the battery and reducing safety accidents caused by battery lithium deposition. It should be understood that the above general description and the detailed description below are only exemplary and explanatory, and do not limit the present application.

Brief Description of the Drawings

[0026] The drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present application and, together with the specification, are used to illustrate the technical solutions of the present application.

[0027] FIG1 is a schematic structural diagram of an embodiment of a vehicle provided by the present application;

[0028] FIG2 is a schematic structural diagram of a first embodiment of a battery system provided by the present application;

[0029] FIG3 is a schematic structural diagram of a second embodiment of a battery system provided by the present application;

[0030] FIG4 is a schematic diagram of the exploded structure of an embodiment of a battery provided by the present application;

[0031] FIG5 is a schematic diagram of the exploded structure of a battery cell according to an embodiment of the present application;

[0032] FIG6 is a schematic structural diagram of a second embodiment of a battery provided by the present application;

[0033] FIG7 is a spectrum diagram of an embodiment of a tilted Bragg grating optical fiber sensor of the present application;

[0034] FIG8 is a schematic structural diagram of a third embodiment of a battery provided by the present application;

[0035] FIG9 is a schematic structural diagram of a fourth embodiment of a battery provided by the present application;

[0036] FIG10 is a flow chart of a first embodiment of a method for detecting lithium deposition in a battery based on an optical fiber sensor provided by the present application;

[0037] FIG11 is a graph showing a first embodiment of the lithium deposition determination scheme of the present invention;

[0038] FIG12 is a graph showing a second embodiment of the lithium deposition determination scheme of the present application;

[0039] FIG13 is a schematic diagram of a flow chart of a first embodiment of step S103 in FIG10 ;

[0040] FIG14 is a schematic diagram of a flow chart of an embodiment of step S201 in FIG13 ;

[0041] FIG15 is a schematic flow chart of a second embodiment of step S103 in FIG10 ;

[0042] FIG16 is a schematic flow chart of a first embodiment of step S105 in FIG10 ;

[0043] FIG17 is a schematic diagram of a flow chart of a second embodiment of step S105 in FIG10 ;

[0044] FIG18 is a flow chart of an embodiment of charging strategy adjustment of the present application. [Specific implementation method]

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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).

[0050] 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.

[0051] The battery lithium deposition detection method based on optical fiber sensor disclosed in the embodiment of the present application can be applied to electrical devices that use batteries as power sources or various energy storage systems that use batteries as energy storage elements, or can also be applied to other computer devices that establish communication connections with electrical devices. Electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, and the like. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0052] As shown in Figure 1, the present application provides an electrical device. The electrical device includes a battery system, wherein the battery system includes a battery and a charge and discharge control module, wherein the battery includes a control module, a battery body, and at least one optical fiber sensor, and the control module is used to execute any of the optical fiber sensor-based battery lithium deposition detection methods provided in the present application.

[0053] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device according to an embodiment of the present application.

[0054] Please refer to Figure 1, which is a schematic diagram of the structure of an embodiment of a vehicle provided in this application. Vehicle 1000 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, among others. Vehicle 1000 includes a battery system 1100, wherein battery system 1100 includes a battery 100 and a charge and discharge control module 400. Charge and discharge control module 400 is used to control the charge and discharge of battery 100. Battery 100 includes a battery body 110 and a control module 200. Battery 100 can be located at the bottom, front, or rear of vehicle 1000. Battery 100 can be used to power vehicle 1000, for example, as an operating power source for vehicle 1000. Vehicle 1000 can also include a motor 300. Control module 200 can execute any of the battery lithium plating detection methods provided in this application while battery 100 is charging. It can also be used to control battery 100 to power motor 300, for example, to meet the power requirements of vehicle 1000 during starting, navigation, and driving.

[0055] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0056] The battery 100 in this embodiment may be a pack including a control module, or may be a battery cell, battery module, or battery module group that does not include a control module. A battery cell may be considered as the smallest unit that makes up a battery. Each battery cell may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. A battery cell may be cylindrical, flat, rectangular, or in other shapes. A battery module may be considered as a whole that is formed by connecting multiple battery cells in series, in parallel, or in a hybrid manner and is housed in a housing. Hybrid means that multiple battery cells are connected in series and in parallel. For example, multiple battery cells may be directly connected in series, in parallel, or in a hybrid manner, and then the whole formed by the multiple battery cells is housed in a housing. A battery module may also be a battery module formed by first connecting multiple battery cells in series, in parallel, or in a hybrid manner, and then the multiple battery modules are connected in series, in parallel, or in a hybrid manner to form a whole and housed in a housing.

[0057] Please refer to Figure 2 , which is a schematic diagram of the structure of a first embodiment of a battery system provided by this application. As shown in Figure 2 , the battery system 1100 of this embodiment includes a battery 100 and a control module 200 .

[0058] In this embodiment, the battery 100 may include at least one battery module, which can provide energy and power for the electric vehicle. In terms of battery type, the battery 100 can be a lithium-ion battery, a lithium metal battery, a lead-acid battery, a nickel-cathode battery, a nickel-metal hydride battery, a lithium-sulfur battery, a lithium-air battery, or a sodium-ion battery, etc., which is not specifically limited in this embodiment of the application. In terms of battery size, in this embodiment of the application, the battery module in the battery 100 can be a battery cell, or a battery pack, which is not specifically limited in this embodiment of the application.

[0059] In addition, in order to intelligently manage and maintain the battery 100, prevent the battery 100 from malfunctioning, and extend the service life of the battery 100, a control module 200 is generally provided in the battery system 1100. The control module 200 is connected to the power battery 100 and is used to monitor and collect the parameters of the battery 100. The control module 200 can also realize control and management of the battery 100 based on the parameters.

[0060] As an example, the control module 200 can be used to monitor parameters such as the voltage, current, and temperature of the battery 100. Specifically, the control module 200 can collect, in real time, the total voltage and current of the battery 100, the voltage and current of individual battery cells within the battery 100, and the temperature of at least one temperature measurement point within the battery 100. Real-time, rapid, and accurate measurement of these parameters is essential for the proper operation of the control module 200.

[0061] Optionally, the control module 200 may further estimate various parameters of the battery 100, such as the state of charge (SOC), state of health (SOH), and state of power (SOP), based on the collected parameters of the battery 100. Furthermore, after the control module 200 obtains various parameters of the battery 100, various controls and management of the battery 100 may be implemented based on the various parameters.

[0062] For example, the control module 200 can control the charge and discharge of the battery 100 based on parameters such as SOC, voltage, current, and optical signals to ensure normal energy supply and release of the battery 100. For another example, the control module 200 can also control components such as cooling fans or heating modules based on parameters such as temperature to achieve thermal management of the battery 100. For another example, the control module 200 can also determine whether the battery 100 is in normal operation based on parameters such as voltage and SOH to implement fault diagnosis and early warning of the battery 100.

[0063] In some embodiments of the present application, please refer to FIG3 , which is a structural diagram of a second embodiment of a battery system provided by the present application. As shown in Figure 3, the battery system 1100 includes a battery 100 and a charge and discharge control module 400, wherein the battery 100 in this embodiment includes a control module 200 and a battery main body 110, wherein the charge and discharge control module 400 is connected to the control module 200 and the battery main body 110. During the battery charging process, the control module 200 is connected to the optical fiber sensor on the battery main body 110, and is used to obtain a first spectral envelope area corresponding to battery lithium plating based on the optical signal output by the optical fiber sensor; obtain the total envelope area of ​​the envelope region of the first spectral signal of the battery during the charging process based on the first spectral signal; obtain a second spectral envelope area corresponding to the internal stress of the battery during the charging process; calculate the difference between the total envelope area and the second spectral envelope area to obtain the first spectral envelope area; determine the lithium plating detection result of the battery based on the first spectral envelope area; the charge and discharge control module 400 is connected to the control module 200 and the battery main body 110, and is used to adjust the charging strategy of the battery 100 in response to lithium plating having occurred or there is a risk of lithium plating during the charging process.

[0064] In some embodiments, as shown in FIG. 3 , the control module 200 includes a light demodulation module 210 and a battery management module 220 .

[0065] The optical demodulation module 210 is connected to the optical fiber sensor and is used to modulate the optical signal output by the optical fiber sensor during the charging process of the battery 100 to obtain a first spectral signal; the battery management module 220 is connected to the optical demodulation module 210 and is used to obtain the total envelope area of ​​the cladding region of the first spectral signal of the battery during the charging process based on the first spectral signal; obtain the second spectral envelope area corresponding to the internal stress of the battery during the charging process; calculate the difference between the total envelope area and the second spectral envelope area to obtain the first spectral envelope area; and determine the lithium plating detection result of the battery based on the first spectral envelope area.

[0066] Therefore, when lithium deposition has occurred or there is a risk of lithium deposition during the charging process of the battery 100, the charge and discharge control module 400 can adjust the charging strategy of the battery 100, thereby reducing the possibility of battery safety problems.

[0067] Please refer to Figure 4, which is a schematic diagram of the decomposed structure of an embodiment of a battery provided in the present application. As mentioned above, the battery 100 in this embodiment can be a pack including a control module, or it can be a battery cell, battery module or battery module that does not include a control module. As shown in Figure 3, in this embodiment, the battery 100 includes a battery case 10 and a battery cell 20, and the battery cell 20 is accommodated in the battery case 10. Among them, the battery case 10 is used to provide a storage space for the battery cell 20, and the battery case 10 can adopt a variety of structures. In some embodiments, the battery case 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a storage space for accommodating the battery cell 20. The second portion 12 can be a hollow structure with one end open, and the first portion 11 can be a plate-like structure. The first portion 11 covers the open side of the second portion 12, so that the first portion 11 and the second portion 12 jointly define a storage space. The first portion 11 and the second portion 12 can also be hollow structures with one end open, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the battery case 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0068] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery 20 may be housed within the battery case 10. Of course, the battery 100 may also be a battery module formed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection, and then the multiple battery modules may be connected in series, in parallel, or in a hybrid connection to form an entire battery 20, and then housed within the battery case 10. The battery 100 may also include other structures, for example, the battery 100 may further include a busbar component for electrically connecting the multiple battery cells 20.

[0069] Each battery cell 20 may be a secondary battery or a primary battery, and may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0070] Please refer to Figure 5, which is a schematic diagram of the exploded structure of an embodiment of a battery cell provided by this application. A battery cell 20 is the smallest unit that makes up a battery. As shown in Figure 3, a battery cell 20 includes an end cap 21, a housing 22, an electrode assembly 23, and other functional components.

[0071] The end cap 21 is a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22. Optionally, the end cap 21 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This prevents the end cap 21 from deforming when subjected to compression or collision, thereby providing the battery cell 20 with greater structural strength and improved safety. The end cap 21 can be provided with functional components such as electrode terminals 21a. The electrode terminals 21a can be used to electrically connect to the electrode assembly 23 for inputting or outputting electrical energy from the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism for relieving internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 21 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this. In some embodiments, an insulating member may be provided inside the end cap 21 to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. For example, the insulating member may be made of plastic, rubber, or the like.

[0072] The housing 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 23, electrolyte, and other components. The sensor can be located at the bottom of the housing 22, for example, at a corner of the housing 22. The housing 22 and the end cap 21 can be independent components. An opening can be provided on the housing 22, and the end cap 21 is closed at the opening to form the internal environment of the battery cell 20. Without limitation, the end cap 21 and the housing 22 can also be integrated. Specifically, the end cap 21 and the housing 22 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 22 needs to be encapsulated, the end cap 21 is closed to the housing 22. The housing 22 can have various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 23. The shell 22 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0073] The electrode assembly 23 is a component in the battery cell 100 where electrochemical reactions occur. One or more electrode assemblies 23 may be contained in the housing 22. The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly, and the parts of the positive and negative electrode sheets without active materials each constitute a tab 23a. The positive and negative electrode tabs 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, the positive active material and the negative active material react with the electrolyte, and the tabs 23a connect the electrode terminals to form a current loop.

[0074] Please refer to Figure 6, which is a schematic structural diagram of a second embodiment of a battery provided in this application. As shown in Figure 6, the battery 100 includes a battery body 110, at least one optical fiber sensor 120, and a control module 200. The detection portion of the optical fiber sensor 120 is disposed inside the battery body 110, wherein the optical fiber sensor 120 is configured to output an optical signal during the charging process of the battery 100, and the control module 200 is connected to the optical fiber sensor 120; wherein the control module 200 is connected to the optical fiber sensor 120, and the control module 200 is used to obtain a first spectral signal corresponding to the optical signal, and obtain the total envelope area of ​​the cladding region of the first spectral signal of the battery during the charging process based on the first spectral signal; obtain a second spectral envelope area corresponding to the internal stress of the battery during the charging process; calculate the difference between the total envelope area and the second spectral envelope area to obtain the first spectral envelope area; and determine the lithium plating detection result of the battery based on the first spectral envelope area.

[0075] In this embodiment, the optical fiber sensor 120 can be configured as a tilted fiber Bragg grating (TFBG) optical fiber sensor. A tilted fiber Bragg grating (TFBG) optical fiber sensor is a special type of fiber Bragg grating (FBG) sensor. It differs from a conventional fiber Bragg grating (FBG) optical fiber sensor in that the grating wave vector direction has a certain intersection angle with the optical fiber axis.

[0076] In this application, the detection portion of the optical fiber sensor 120 is disposed inside the battery body 110 . If the optical fiber sensor 120 is a tilted Bragg grating optical fiber sensor, the grating portion 121 of the tilted Bragg grating optical fiber sensor is disposed inside the battery body 110 .

[0077] Among them, the principle of lithium plating measurement of the tilted Bragg grating fiber sensor is as follows. The optical signal output by the tilted Bragg grating fiber sensor will form a spectrum diagram as shown in Figure 7 after demodulation. As shown in Figure 7, Figure 7 is a spectrum diagram of an embodiment of the tilted Bragg grating fiber sensor of the present application. The "comb"-like area in Figure 7 is its cladding area. The cladding area is more sensitive to changes in ion concentration in the electrolyte inside the battery 100. When the negative electrode of the battery 100 is charged to a certain state of charge, the ion concentration on its surface is closely related to lithium plating. When the ion concentration exceeds a certain value, lithium plating begins to occur on the surface of the negative electrode. Therefore, the spectral signal of the battery can be obtained by demodulating the optical signal of the optical fiber sensor 120, and the change in the area of ​​the cladding area of ​​the spectral signal can be monitored to achieve real-time lithium plating detection. Specifically, the envelope area enclosed by the upper and lower envelope lines of the cladding area can be calculated and compared with the threshold to determine whether lithium plating occurs in the battery 100.

[0078] Therefore, the battery 100 of the present application can obtain an optical signal during the charging process of the battery 100 by setting the detection part of the optical fiber sensor 120 inside the battery body 110. The control module 200 can reduce the interference of the internal stress of the battery on the lithium plating detection by analyzing the spectral signal corresponding to the optical signal, and quickly obtain the first spectral envelope area corresponding to the lithium plating of the battery during the charging process, thereby confirming the lithium plating situation inside the battery 100 and reducing the risk of safety problems of the battery 100.

[0079] In some embodiments, as shown in FIG6 , the optical fiber sensor 120 includes at least one grating portion 121 and a transmission optical fiber 122 connected to the grating portion. The grating portion 121 is disposed inside the battery body 110. Thus, the optical fiber sensor 120 can obtain optical signals during the charging process of the battery 100 through the grating portion 121 disposed inside the battery 100.

[0080] In some embodiments, as shown in Figure 6, the input end of the transmission optical fiber 122 is used to transmit the incoming initial light signal, and the output end is used to output the light signal during the charging process. The input end and the output end of the transmission optical fiber 122 are both arranged outside the battery body 110, and the middle connection part between the input end and the output end of the transmission optical fiber 122 is arranged inside the battery body 110.

[0081] In this embodiment, the transmission optical fiber 122 is configured to be connected to an optical demodulation module (not shown), which inputs an initial optical signal from the input end and receives an optical signal output from the output end of the transmission optical fiber 122. At this time, if the optical demodulation module wants to receive the optical signal output from the output end, a circulator 140 needs to be set.

[0082] Therefore, by inputting the initial optical signal at the input end and analyzing the optical signal output at the output end of the transmission optical fiber, the lithium plating detection results inside the battery during the charging process can be quickly obtained, thereby effectively reducing the hazards of lithium plating inside the battery 100 and reducing safety accidents caused by lithium plating of the battery 100.

[0083] In some embodiments, please refer to Figure 8, which is a schematic diagram of the structure of the third embodiment of the battery provided by this application. As shown in Figure 8, the control module 200 is connected to the optical fiber sensor 120, the battery body 110 is provided with a reflective layer 111, the input end of the transmission optical fiber 122 is provided outside the battery body 110, and the output end of the transmission optical fiber 122 is provided inside the battery body 110 and abuts against the reflective layer 111, wherein the reflective layer 111 is used to reflect the initial light signal incident from the input end so that the output light signal is transmitted outward from the input end.

[0084] The material of the reflective layer 111 includes, but is not limited to, gold or single-crystal silicon. In this embodiment, the reflective layer 111 allows the optical signal, which would otherwise need to be output from the output end, to be directly transmitted from the input end. This design eliminates the need to route the output end of the transmission optical fiber 122 out of the battery 100 and eliminates the need for a circulator 140.

[0085] Therefore, by providing the reflective layer 111 inside the battery 100 , there is no need to lead the output end of the transmission optical fiber 122 out of the battery, thereby simplifying the structure of the battery 100 and improving the convenience of manufacturing the battery 100 .

[0086] In some embodiments, based on the above embodiments, the transmission optical fiber 122 includes a core and a cladding, and the diameter of the cladding is set to be between 25 μm and 125 μm. Therefore, setting the cladding diameter between 25 μm and 125 μm can reduce the negative impact that the transmission optical fiber 122 may have on the battery 100, while also ensuring that the transmission optical fiber 122 has good mechanical properties.

[0087] In some embodiments, the transmission optical fiber 122 includes a core and a cladding, and the diameter of the cladding is set to be between 50 μm and 100 μm.

[0088] The diameter of the cladding is preferably 50 μm.

[0089] Therefore, the negative impact that the transmission optical fiber 122 may have on the battery 100 can be further reduced, and the mechanical properties of the transmission optical fiber 122 can be further improved.

[0090] In some embodiments, the length of the grating portion 121 is set to be between 0.3 cm and 1.2 cm. Therefore, setting the length of the grating portion 121 to be between 0.3 cm and 1.2 cm can improve the efficiency and accuracy of acquiring the optical signal and reduce the negative impact that the transmission optical fiber 122 may have on the battery 100.

[0091] In some embodiments, the length of the grating portion 121 is set to be between 0.5 cm and 1 cm, thereby further improving the efficiency and accuracy of acquiring the optical signal and further reducing the negative impact that the transmission optical fiber 122 may have on the battery 100 .

[0092] In addition, in this embodiment, the grating period and central wavelength of the optical fiber sensor 120 are not limited, and the tilt angle of the grating portion 121 can be set to 1-45°.

[0093] In some embodiments, please refer to FIG9 , which is a schematic structural diagram of a fourth embodiment of a battery provided in this application.

[0094] In some embodiments, as shown in Figure 9, the control module 200 includes an optical demodulation module 210 and a battery management module 220. The optical demodulation module 210 is connected to the optical fiber sensor 120 and is used to modulate the optical signal output by the optical fiber sensor 120 during the charging process of the battery to obtain a first spectral signal; the battery management module 220 is connected to the optical demodulation module 210 and is used to obtain the total envelope area of ​​the cladding region of the first spectral signal of the battery during the charging process based on the first spectral signal; obtain the second spectral envelope area corresponding to the internal stress of the battery during the charging process; calculate the difference between the total envelope area and the second spectral envelope area to obtain the first spectral envelope area; and determine the lithium plating detection result of the battery based on the first spectral envelope area.

[0095] The battery management module 220 includes one of a BMS system and a VCU.

[0096] The BMS (Battery Management System), commonly known as a battery nanny or battery steward, is primarily responsible for intelligently managing and maintaining individual battery cells, such as preventing overcharging and over-discharging, extending battery life, and monitoring battery status. The VCU can be considered the vehicle control unit (VCU). The VCU is a key component of the electronic control system for pure electric vehicles. Similar to the engine management system (EMS) in traditional internal combustion engine vehicles, the VCU of a pure electric vehicle effectively allocates energy and maximizes the efficiency of onboard battery energy utilization. The electronic control unit (VCU) within the VCU is the core of the VCU system. With the increasing number of electronic devices and control systems in electric vehicles, advanced vehicle control architectures are crucial for ensuring safe and reliable driving and improving data transmission efficiency between various control systems. The VCU of an electric vehicle implements functions such as motor drive control, temperature control, and energy management control. It primarily consists of subsystems such as sensor input and switch systems, system drive outputs, and control unit output systems.

[0097] Therefore, the optical demodulation module 210 can demodulate the optical signal of the optical fiber sensor to obtain a first spectral signal, and the battery management module 220 can analyze the lithium deposition situation inside the battery based on the first spectral signal to obtain the battery lithium deposition detection result, thereby effectively reducing the hazards of lithium deposition inside the battery and reducing safety accidents caused by battery lithium deposition.

[0098] Optionally, please refer to Figure 10, which is a flow chart of the first embodiment of the battery lithium deposition detection method based on the optical fiber sensor provided in the present application. As shown in Figure 10, the battery lithium deposition detection method specifically includes steps S101 to S105: Step S101: Obtain a first optical signal output by the optical fiber sensor during the battery charging process. Step S102: Obtain a first spectral signal corresponding to the first optical signal, and obtain the total envelope area of ​​the cladding region of the first spectral signal of the battery during the charging process based on the first spectral signal. Step S103: Obtain a second spectral envelope area corresponding to the internal stress of the battery during the charging process. Step S104: Calculate the difference between the total envelope area and the second spectral envelope area to obtain the first spectral envelope area. Step S105: Determine the lithium deposition detection result of the battery based on the first spectral envelope area.

[0099] The fiber optic sensor-based battery lithium deposition detection method provided in this application can be applied to the power device provided in the above power device embodiment, and can also be applied to the battery 100 provided in the above battery embodiment. The battery can be any of the above, such as a pack including a controller, or a battery cell, battery module, or battery assembly.

[0100] As mentioned above, the envelope region of the spectral signal is more sensitive to changes in the ion concentration in the electrolyte inside the battery. When the negative electrode of the battery is charged to a certain state of charge, the ion concentration on its surface is closely related to lithium deposition. When the ion concentration exceeds a certain value, lithium deposition begins on the negative electrode surface. Therefore, the spectral signal of the battery can be obtained by demodulating the optical signal of the optical fiber sensor and monitoring the changes in the envelope area of ​​the spectral signal to achieve real-time lithium deposition detection. Specifically, the envelope area enclosed by the upper and lower envelope lines of the envelope region can be calculated and compared with a threshold to determine whether the battery has deposited lithium.

[0101] However, in addition to being affected by ion concentration, the envelope area is also affected by the internal stress of the battery. Therefore, after obtaining the total envelope area surrounded by the upper and lower envelope lines of the spectral signal envelope area, it is also necessary to calculate the second spectral envelope area corresponding to the internal stress of the battery during the charging process; the first spectral envelope area corresponding to the lithium plating of the battery can be obtained by subtracting the total envelope area from the second spectral envelope area.

[0102] In the above scheme, the battery lithium deposition detection method of the present application can reduce the interference of internal stress of the battery on lithium deposition detection by analyzing the spectral signal, and quickly obtain the first spectral envelope area corresponding to battery lithium deposition during the charging process, thereby confirming the lithium deposition situation inside the battery.

[0103] In some embodiments, the step of obtaining a second spectral envelope area corresponding to the internal stress of the battery during the charging process includes: obtaining the actual internal stress of the battery during the charging process; obtaining the second spectral envelope area corresponding to the internal stress of the battery based on the actual internal stress and the mapping relationship; wherein the mapping relationship includes the correspondence between the internal stress of the battery and the envelope area of ​​the spectral signal under the internal stress.

[0104] The actual internal stress and temperature of the battery during charging are also correlated with the spectral signal. As shown in Figure 7, the spectral signal shows phantom and core modes. Changes in the battery's temperature and actual internal stress during charging will cause wavelength shifts in the phantom and core modes in the spectral signal. Furthermore, the phantom and core modes have different sensitivity coefficients to temperature and actual internal stress, respectively. Therefore, by measuring the wavelength changes of the phantom and core modes during charging and establishing a stress analysis matrix, we can directly decouple the battery's temperature and actual internal stress during charging. The specific stress analysis matrix is ​​described below and will not be repeated here.

[0105] After obtaining the actual internal stress of the battery during charging, the second spectrum envelope area corresponding to the internal stress of the battery can be obtained according to the mapping relationship between the internal stress of the battery and the envelope area of ​​the spectrum signal under the internal stress.

[0106] The mapping relationship may be acquired before the battery charging process. The specific acquisition method is described below and will not be repeated here.

[0107] Therefore, by obtaining the mapping relationship between the internal stress and the envelope area during the battery charging process, the second spectrum envelope area corresponding to the internal stress during the battery charging process can be quickly obtained, thereby reducing the interference of the internal stress on the lithium plating detection result during the charging process.

[0108] In some embodiments, the step of obtaining the actual internal stress of the battery during the charging process includes: obtaining the wavelength change of the first spectral signal; and obtaining the actual internal stress of the battery during the charging process based on the wavelength change in the first spectral signal and the stress analysis matrix of the battery.

[0109] As mentioned above, changes in temperature and actual internal stress during battery charging will cause wavelength drift of the phantom mode and core mode in the spectral signal; and the phantom mode and core mode have different sensitivity coefficients to temperature and actual internal stress, which are K core，F , K core，T , K ghost，F , K ghost，T Therefore, it is necessary to obtain the wavelength variation of the phantom mode and the core mode in the first spectrum signal. After obtaining the wavelength variation of the phantom mode and the core mode, the actual internal stress of the battery during the charging process can be obtained by inputting them into the stress analysis matrix.

[0110] Its stress analysis matrix is ​​shown below:

[0111] Where Δλ core is the wavelength change of the core mode, Δλ ghost is the wavelength change of the phantom mode, K core，F K is the response sensitivity coefficient of the core mode to stress, core，T K is the temperature sensitivity coefficient of the core mode. ghost，F K is the response sensitivity coefficient of the phantom model to stress, ghost，T is the response sensitivity coefficient of the phantom mode to temperature, F is stress, and T is temperature.

[0112] Among them, K core，F , K core，T , K ghost，F , K ghost，TThese four response sensitivity coefficients can be obtained through experimentation, and in other embodiments, other methods can also be used to obtain them. Specifically, when obtaining the actual internal stress of the battery during charging, the four response sensitivity coefficients are known. In this embodiment, it is only necessary to obtain the wavelength changes of the phantom mode and core mode in the spectral signal, input them into the stress analysis matrix for decoupling, and thus obtain the actual internal stress and temperature of the battery during charging.

[0113] Therefore, based on the wavelength variation of the first spectral signal and the stress analysis matrix corresponding to the battery, the actual internal stress of the battery during the charging process can be quickly obtained, thereby improving the efficiency of battery lithium deposition detection.

[0114] In some embodiments, before obtaining the actual internal stress of the battery during the charging process, the battery lithium plating detection method also includes: charging the battery at a preset rate, and obtaining a second optical signal of the battery during the preset rate charging process; obtaining a second spectral signal corresponding to the second optical signal, and recording the wavelength change and the envelope area change of the cladding region in the second spectral signal; obtaining stress data of the battery based on the wavelength change in the second spectral signal and the stress analysis matrix of the battery; and performing fitting based on the stress data and the envelope area change to obtain a mapping relationship.

[0115] As mentioned above, when obtaining the second spectrum envelope area corresponding to the internal stress based on stress, it is necessary to obtain the mapping relationship between the internal stress and the envelope area during the battery charging process. The process of obtaining this mapping relationship is as follows:

[0116] First, the battery is charged at a preset rate, where the preset rate can be set to be lower than the normal charging rate. At this time, a second spectral signal of the battery during the preset rate charging process is obtained, and the changes in the core mode and the phantom mode in the second spectral signal, as well as the changes in the envelope area of ​​the cladding region, are recorded.

[0117] At this point, the stress analysis matrix mentioned above can be used to decouple the changes in the core mode and the phantom mode to obtain the stress data of the battery; finally, fitting is performed based on the stress data and the envelope area change to obtain the mapping relationship.

[0118] Therefore, before performing a charge lithium deposition test on the battery, the battery can be charged at a preset rate to obtain a mapping relationship between the internal stress and the envelope area of ​​different batteries, thereby improving the accuracy of the battery lithium deposition test results.

[0119] In some embodiments, the step of determining the lithium plating detection result of the battery based on the first spectral envelope area includes: in response to the first spectral envelope area being greater than or equal to the corresponding first preset envelope area threshold, determining that lithium plating has occurred in the battery; in response to the first spectral envelope area being less than the corresponding first preset envelope area threshold and greater than or equal to the corresponding second preset envelope area threshold, determining that the battery has a risk of lithium plating, wherein the second preset envelope area threshold is less than the first preset envelope area threshold.

[0120] Please refer to Figure 11, which is a graph of the first embodiment of the lithium plating judgment scheme of the present application. During the battery charging process, it is necessary to obtain the first envelope area corresponding to lithium plating at each state of charge during the battery charging process and compare it with the corresponding first preset envelope area threshold and second preset envelope area threshold. As shown by curve a in Figure 11, in response to the first spectrum envelope area being less than the corresponding second preset envelope area threshold at a certain state of charge, it is determined that the battery has no lithium plating risk at that state of charge; as shown by curve b in Figure 11, in response to the first spectrum envelope area being less than the corresponding first preset envelope area threshold and greater than or equal to the corresponding second preset envelope area threshold at a certain state of charge, it is determined that the battery has a lithium plating risk at that state of charge; as shown by curve c in Figure 11, in response to the first spectrum envelope area being greater than or equal to the corresponding first preset envelope area threshold at a certain state of charge, it is determined that lithium plating has occurred at that state of charge.

[0121] Therefore, by comparing the first spectral envelope area corresponding to lithium plating, the first preset envelope area threshold and the second preset envelope area threshold, it is possible to quickly determine whether lithium plating has occurred in the battery or there is a risk of lithium plating, thereby enabling real-time detection of the internal lithium plating of the battery and reducing the risk of safety problems caused by lithium plating inside the battery.

[0122] In some embodiments, the step of determining the lithium plating detection result of the battery based on the first spectral envelope area includes: normalizing the first spectral envelope area; in response to the normalized first spectral envelope area being greater than or equal to the corresponding first preset percentage threshold, determining that lithium plating has occurred in the battery; in response to the normalized first spectral envelope area being less than the corresponding first preset percentage threshold and greater than or equal to the corresponding second preset percentage threshold, determining that the battery has a lithium plating risk, wherein the second preset percentage threshold is less than the first preset percentage threshold.

[0123] As mentioned above, during the battery charging process, it is necessary to obtain the first envelope area corresponding to lithium deposition at each state of charge during the battery charging process, and compare it with the corresponding first preset envelope area threshold and second preset envelope area threshold to make a lithium deposition judgment. However, due to the consistency of TFBG sensor processing and manufacturing, it will cause deviations in the thresholds, resulting in it being difficult to give a uniformly applicable threshold for different TFBGs. To address this issue, it is necessary to normalize the first envelope area corresponding to lithium deposition at each state of charge during the battery charging process, that is, to obtain the first envelope area S0 corresponding to lithium deposition when the battery state of charge is 0. After the battery starts charging, it continuously calculates S N , and define W=S N / S0*100%, and compare W with the W threshold to determine whether lithium deposition occurs, wherein the W threshold is the first preset percentage threshold and the second preset percentage threshold.

[0124] Please refer to Figure 12, which is a graph of the second embodiment of the lithium plating determination scheme of the present application. As shown by curve a in Figure 12, in response to the normalized first spectral envelope area at a certain state of charge being less than the corresponding second preset percentage threshold, it is determined that the battery has no lithium plating risk at that state of charge; as shown by curve b in Figure 12, in response to the normalized first spectral envelope area at a certain state of charge being less than the corresponding first preset percentage threshold and greater than or equal to the corresponding second preset percentage threshold, it is determined that the battery has a lithium plating risk at that state of charge; as shown by curve c in Figure 12, in response to the normalized first spectral envelope area at a certain state of charge being greater than or equal to the corresponding first preset percentage threshold, it is determined that lithium plating has occurred at that state of charge.

[0125] Therefore, by normalizing the first spectrum envelope area, the problem that it is difficult to provide a unified lithium deposition determination threshold due to differences between different optical fiber sensors can be solved.

[0126] In some embodiments, after the step of determining the battery lithium deposition detection result based on the first spectral envelope area, the battery lithium deposition detection method further includes: adjusting the battery charging strategy in response to lithium deposition having occurred or there is a risk of lithium deposition during the charging process.

[0127] If the battery's lithium plating test result indicates that lithium plating has occurred or is at risk, it means that the battery may have plating or is about to plating. Lithium plating will deteriorate battery performance, and further dendritic lithium may puncture the diaphragm, causing a short circuit in the battery and leading to a safety accident. In such cases, it is necessary to adjust the charging strategy to effectively avoid lithium plating or reduce the harm of lithium plating. The specific method for adjusting the charging strategy is described below and will not be repeated here.

[0128] Therefore, when lithium plating has occurred or there is a risk of lithium plating during the battery charging process, adjusting the battery charging strategy can reduce the possibility of battery safety problems.

[0129] In some embodiments, the step of adjusting the charging strategy of the battery includes: in response to the lithium deposition detection result indicating that there is a risk of lithium deposition, reducing the charging current of the battery to charge the battery until the lithium deposition detection result of the battery indicates that there is no risk of lithium deposition; in response to the lithium deposition detection result indicating that lithium deposition has occurred, stopping charging the battery and reverse-discharging the battery, and reducing the charging current of the battery when charging the battery after reverse discharge.

[0130] Among them, when adjusting the battery charging strategy, there are three corresponding strategies based on the three lithium deposition test results. First, if there is clearly no lithium deposition risk, the charging strategy does not need to be changed; second, if the lithium deposition test results show that there is a lithium deposition risk at a certain state of charge or multiple states of charge, the current charging current is reduced by 5% and charging continues until the alarm of lithium deposition risk is no longer present; if the lithium deposition test results show that lithium deposition has occurred at a certain state of charge or multiple states of charge, charging of the battery is stopped and reversely discharged with a discharge current between 1C and 3C and a discharge duration between 5s and 15s. Charging is then resumed after the discharge is completed, and the charging current is reduced by another 10%.

[0131] In other embodiments, the above-mentioned ratio of reducing the charging current, the size of the discharge circuit, the discharge duration, and the size of the recharging current can all be set based on the actual situation of the battery and are not limited here.

[0132] For example, if a battery with a health status of 90% is charged with a constant current at an initial current of 5C, and the signal calculation obtained by the optical fiber sensor when charged to a 50% state of charge shows that the first preset envelope area threshold > the first spectral envelope area > the second preset envelope area threshold (or the first preset percentage threshold > the first spectral envelope area after normalization > the second preset percentage threshold), then it is determined that there is a risk of lithium plating when the battery is charged at 5C starting from a 50% state of charge, then the subsequent charging current is reduced by 5% starting from the 50% state of charge, that is, charging is continued at a current of 4.75C. If the battery continues to be charged at a constant current of 4.75C to a state of charge of 60%, the signal calculation obtained by the optical fiber sensor shows that the first preset envelope area threshold > the first spectral envelope area > the second preset envelope area threshold (or the first preset percentage threshold > the first spectral envelope area after normalization > the second preset percentage threshold), then it is determined that there is a risk of lithium plating when charging at 4.75C starting from the state of charge of 60%. Therefore, the subsequent charging current is reduced by 5% starting from the 60% state of charge, that is, charging is continued at a current of 4.5C; the subsequent charging process is analogous.

[0133] For example, a battery is charged at an initial constant current of 4C. When the battery reaches a 30% state of charge (SOC), the signal calculated from the optical fiber sensor indicates that the first preset envelope area threshold > the first spectral envelope area > the second preset envelope area threshold (or the first preset percentage threshold > the normalized first spectral envelope area > the second preset percentage threshold). Therefore, it is determined that there is a risk of lithium deposition with 4C charging starting at 30% SOC. The subsequent charging current is reduced by 5% from 30% SOC, i.e., charging is continued at 3.8C. If the battery continues to be charged at 3.8C to 32% SOC, the signal calculated from the optical fiber sensor indicates that the first spectral envelope area > the first preset envelope area threshold (or the normalized first spectral envelope area > the first preset percentage threshold), it is determined that lithium deposition has occurred in the battery at 32% SOC. Charging is stopped and the battery is discharged at 2.5C for 10S. After discharge, charging is resumed, and the charging current is reduced by another 10% from the 3.8C current, i.e., charging is continued at 3.4C.

[0134] Therefore, during the battery charging process, when the battery lithium deposition test result indicates that there is a risk of lithium deposition or lithium deposition has occurred, the possibility of safety problems in the battery during the subsequent charging process can be reduced by reducing the charging current or stopping charging the battery and charging it in the reverse direction. It can also maximize the charging speed, avoid the occurrence of lithium deposition in the subsequent charging process, eliminate the lithium deposited in the battery, and reduce the harm of lithium deposition.

[0135] Please refer to FIG10 . The battery lithium deposition detection method based on the optical fiber sensor provided in the present application specifically includes steps S101 to S105:

[0136] Step S101: Acquire a first optical signal output by an optical fiber sensor during battery charging.

[0137] During the charging process, the control module obtains a first optical signal output by an optical fiber sensor arranged on the battery.

[0138] Step S102: obtaining a first spectral signal corresponding to the first optical signal, and obtaining a total envelope area of ​​an envelope region of the first spectral signal during the battery charging process based on the first spectral signal.

[0139] As mentioned above, the envelope region of the spectral signal is sensitive to changes in the ion concentration of the electrolyte inside the battery. When the battery's negative electrode is charged to a certain state of charge, the ion concentration on its surface is closely related to lithium deposition. When the ion concentration exceeds a certain value, lithium deposition begins on the negative electrode surface. Therefore, monitoring changes in the envelope region of the spectral signal enables real-time lithium deposition detection.

[0140] Therefore, it is first necessary to obtain the total envelope area of ​​the envelope region of the first spectrum signal during the battery charging process. The total envelope area is the envelope area enclosed by the upper and lower envelope lines of the envelope region.

[0141] Step S103: obtaining a second spectrum envelope area corresponding to the internal stress of the battery during the charging process.

[0142] However, the envelope region is not only affected by ion concentration but also by the internal stress of the battery. Therefore, after obtaining the total envelope area enclosed by the upper and lower envelope lines of the spectral signal envelope region, it is necessary to obtain a second spectral envelope area corresponding to the internal stress of the battery during charging. The method for calculating the second spectral envelope area is described below.

[0143] Step S104: Calculate the difference between the total envelope area and the second spectrum envelope area to obtain the first spectrum envelope area.

[0144] By calculating the difference between the total envelope area and the second spectral envelope area, the envelope area change caused by stress can be removed from the total envelope area of ​​working condition charging to obtain the first spectral envelope area corresponding to lithium plating.

[0145] Step S105: determining a lithium plating detection result of the battery based on the first spectrum envelope area.

[0146] After obtaining the first spectrum envelope area corresponding to the lithium deposition of the battery, the first spectrum envelope area is compared with the spectrum envelope area to determine the lithium deposition detection result of the battery.

[0147] Alternatively, please refer to Figure 13, which is a flowchart of a first embodiment of step S103 in Figure 10. In this embodiment, step S103 can be implemented by the method shown in Figure 13, and the specific implementation steps include steps S201 to S202:

[0148] Step S201: obtaining the actual internal stress of the battery during the charging process.

[0149] The control module can calculate the actual internal stress of the battery during the charging process based on the first spectral signal. The specific calculation method is as follows.

[0150] Specifically, please refer to Figure 14, which is a flowchart of an embodiment of step S201 in Figure 13. In this embodiment, step S201 can be implemented by the method shown in Figure 14, and the specific implementation steps include steps S301 to S302:

[0151] Step S301: Acquire the wavelength variation of the first spectrum signal.

[0152] As shown in Figure 7, the spectrum signal graph shows phantom and core modes. Changes in battery temperature and actual internal stress during charging can cause wavelength shifts in these modes. This is because obtaining the actual internal stress requires first determining the wavelength shifts in the phantom and core modes in the first spectrum signal.

[0153] Step S302: obtaining the actual internal stress of the battery during the charging process based on the wavelength variation in the first spectral signal and the stress analysis matrix of the battery.

[0154] Among them, when obtaining the wavelength variation of the phantom mode and the core mode in the first spectrum signal, the wavelength variation of the phantom mode and the core mode can be brought into the stress analysis matrix for decoupling, thereby obtaining the actual internal stress of the battery during the charging process.

[0155] The stress analysis matrix is ​​as described above, and represents the mapping relationship between the wavelength variation of the phantom mode and the core mode and the actual internal stress and temperature inside the battery.

[0156] Step S202: obtaining a second spectrum envelope area corresponding to the internal stress of the battery based on the actual internal stress and a mapping relationship; wherein the mapping relationship includes a correspondence between the internal stress of the battery and the envelope area of ​​the spectrum signal under the internal stress.

[0157] After obtaining the actual internal stress generated during the battery charging process, Bina can calculate the second spectrum envelope area based on the mapping relationship between the actual internal stress, the internal stress of the battery, and the envelope area of ​​the spectrum signal under the internal stress.

[0158] The mapping relationship between the internal stress of the battery and the envelope area of ​​the spectral signal under the internal stress can be obtained through experiments.

[0159] In some embodiments, please refer to Figure 15, which is a flowchart of a second embodiment of step S103 in Figure 10. In this embodiment, step S103 can be implemented by the method shown in Figure 15, and the specific implementation steps include steps S401 to S406:

[0160] Step S401: charging a battery at a preset rate, and acquiring a second optical signal of the battery during the charging process at the preset rate.

[0161] Before obtaining the mapping relationship between the second spectrum envelope area corresponding to the internal stress based on the stress, it is necessary to obtain the mapping relationship between the internal stress and the envelope area during the battery charging process through experiments or simulations.

[0162] In this embodiment, before the battery is normally charged, the battery may be charged at a preset rate to obtain a second optical signal during the battery charging process at the preset rate, wherein the preset rate may be set to be lower than the normal charging rate.

[0163] Step S402: obtaining a second spectrum signal corresponding to the second optical signal, and recording a wavelength change and an envelope area change of the cladding region in the second spectrum signal.

[0164] During the preset rate charging process, a second optical signal from the optical fiber sensor provided on the battery can be obtained, and the second optical signal can be demodulated to obtain a corresponding second spectral signal. At this time, the changes in the core mode and the phantom mode in the second spectral signal are recorded; and the changes in the envelope area of ​​the envelope region of the second spectral signal are recorded.

[0165] Step S403: Obtaining stress data of the battery based on the wavelength variation in the second spectral signal and the stress analysis matrix of the battery.

[0166] After obtaining the changes in the core mode and phantom mode in the second spectral signal, the changes in the core mode and phantom mode in the second spectral signal can be brought into the stress analysis matrix based on the stress analysis matrix mentioned above for decoupling, so that the stress data of the battery corresponding to the second spectral signal can be obtained.

[0167] Step S404: performing fitting based on the stress data and the envelope area change to obtain a mapping relationship.

[0168] Based on the corresponding battery stress data and the envelope area change of the envelope region of the second spectrum signal, the two are fitted to obtain a mapping relationship of the second spectrum envelope area corresponding to the internal stress.

[0169] Step S405: obtaining the actual internal stress of the battery during the charging process.

[0170] Step S405 is the same as step S201 and will not be described again.

[0171] Step S406: obtaining a second spectrum envelope area corresponding to the internal stress of the battery based on the actual internal stress and the mapping relationship; wherein the mapping relationship includes a correspondence between the internal stress of the battery and the envelope area of ​​the spectrum signal under the internal stress.

[0172] Step S406 is the same as step S202 and will not be described again.

[0173] In some embodiments, please refer to Figure 16, which is a flowchart of a first embodiment of step S105 in Figure 10. In this embodiment, step S105 can be implemented by the method shown in Figure 16, and the specific implementation steps include steps S501 to S502:

[0174] Step S501: In response to a first spectrum envelope area being greater than or equal to a corresponding first preset envelope area threshold, it is determined that lithium plating has occurred in the battery.

[0175] After obtaining the first spectral envelope area corresponding to battery lithium deposition at each state of charge during the battery charging process, the control module compares the first spectral envelope area at each state of charge with the corresponding first preset envelope area threshold and second preset envelope area threshold (wherein the first preset envelope area threshold is greater than the second preset envelope area threshold). In response to the first spectral envelope area being greater than or equal to the corresponding first preset envelope area threshold, it is determined that lithium deposition has occurred in the battery.

[0176] Step S502: In response to the first spectrum envelope area being less than a corresponding first preset envelope area threshold and greater than or equal to a corresponding second preset envelope area threshold, determining that the battery has a lithium plating risk, wherein the second preset envelope area threshold is less than the first preset envelope area threshold.

[0177] After obtaining the first spectral envelope area corresponding to battery lithium deposition at each state of charge during the battery charging process, the control module compares the first spectral envelope area at each state of charge with the corresponding first preset envelope area threshold and second preset envelope area threshold (wherein the first preset envelope area threshold is greater than the second preset envelope area threshold). In response to the first spectral envelope area being less than the corresponding first preset envelope area threshold and greater than or equal to the corresponding second preset envelope area threshold, the control module determines that the battery has a risk of lithium deposition.

[0178] In some embodiments, please refer to Figure 17, which is a flowchart of a second embodiment of step S105 in Figure 10. In this embodiment, step S105 can be implemented by the method shown in Figure 17, and the specific implementation steps include steps S601 to S603:

[0179] Step S601: performing normalization processing on the first spectrum envelope area.

[0180] Due to the consistency of fiber optic sensor manufacturing, threshold values ​​can vary, making it difficult to determine a single, universally applicable threshold for different fiber optic sensors. To address this issue, it is necessary to normalize the first envelope area corresponding to lithium deposition at each state of charge during the battery charging process.

[0181] In this embodiment, the first envelope area S0 corresponding to lithium deposition when the battery state of charge is 0 is obtained. After the battery starts charging, S N , and define W=S N / S0*100%.

[0182] In other embodiments, other methods may be used to normalize the first spectrum envelope area, which are not limited here.

[0183] Step S602: In response to the normalized first spectrum envelope area being greater than or equal to the corresponding first preset percentage threshold, it is determined that lithium plating has occurred in the battery.

[0184] The control module compares the normalized first spectral envelope area W with a first preset percentage threshold and a second preset percentage threshold (wherein the first preset percentage threshold is greater than the second preset percentage threshold). In response to the normalized first spectral envelope area W being greater than or equal to the corresponding first preset percentage threshold, it is determined that lithium plating has occurred in the battery.

[0185] Step S603: In response to the normalized first spectral envelope area being less than a corresponding first preset percentage threshold and greater than or equal to a corresponding second preset percentage threshold, determining that the battery has a lithium plating risk, wherein the second preset percentage threshold is less than the first preset percentage threshold.

[0186] The control module determines that the battery has a lithium plating risk in response to the normalized first spectrum envelope area W being less than a corresponding first preset percentage threshold and greater than or equal to a corresponding second preset percentage threshold.

[0187] In some embodiments, the battery lithium deposition detection method based on the optical fiber sensor provided in the present application further includes the following steps:

[0188] In response to lithium plating occurring in the battery or the risk of lithium plating occurring during charging, the charging strategy of the battery is adjusted.

[0189] When lithium plating has occurred or there is a risk of lithium plating during the battery charging process, adjusting the battery charging strategy can reduce the possibility of battery safety problems.

[0190] Optionally, please refer to Figure 18, which is a flowchart of an embodiment of the charging strategy adjustment of the present application. As shown in Figure 18, the specific implementation steps of this embodiment include steps S701 to S702:

[0191] Step S701: In response to a lithium deposition detection result indicating that there is a risk of lithium deposition, the charging current of the battery is reduced to charge the battery until the lithium deposition detection result of the battery indicates that there is no risk of lithium deposition.

[0192] Specifically, if the lithium deposition detection results in a certain state of charge or multiple states of charge all indicate that there is a risk of lithium deposition, the current charging current is reduced by 5% and charging is continued until the alarm of the risk of lithium deposition is no longer given.

[0193] Step S702: In response to the lithium deposition detection result indicating that lithium deposition has occurred, charging of the battery is stopped, and the battery is reversely discharged. When the battery is charged after the reverse discharge, the charging current of the battery is reduced.

[0194] Specifically, if the lithium deposition detection results show that lithium deposition has occurred under a certain state of charge or multiple states of charge, the battery will stop charging and be discharged in the reverse direction. The discharge current is between 1C and 3C, and the discharge duration is between 5s and 15s. After the discharge is completed, charging will be continued, and the charging current will be reduced by 10% again.

[0195] In other embodiments, the above-mentioned ratio of reducing the charging current, the size of the discharge circuit, the discharge duration, and the size of the recharging current can all be set based on the actual situation of the battery and are not limited here.

[0196] Different from the existing technology, the battery lithium deposition detection method of the present application can reduce the interference of internal stress of the battery on lithium deposition detection by analyzing the spectral signal, quickly obtain the first spectral envelope area corresponding to battery lithium deposition during the charging process, and confirm the lithium deposition situation inside the battery, thereby effectively reducing the hazards of lithium deposition inside the battery and reducing safety accidents caused by battery lithium deposition.

[0197] The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced with each other and will not be repeated herein for the sake of brevity.

[0198] In the several embodiments provided in this application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device implementation methods described above are only schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation. For example, units or components can be combined or integrated into another subsystem, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0199] In addition, the functional units in the various embodiments of the present application can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit. If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes various media that can store program code, 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.

Claims

1. A battery lithium deposition detection method based on optical fiber sensor, wherein: The detection part of the optical fiber sensor is arranged inside the battery, and the battery lithium deposition detection method comprises: Acquire a first optical signal output by the optical fiber sensor during the charging process of the battery; Acquire a first spectral signal corresponding to the first optical signal, and acquire a total envelope area of ​​an envelope region of the first spectral signal during charging of the battery based on the first spectral signal; Obtaining a second spectrum envelope area corresponding to the internal stress of the battery during the charging process; Calculating a difference between the total envelope area and the second spectrum envelope area to obtain a first spectrum envelope area; A lithium plating detection result of the battery is determined based on the first spectral envelope area.

2. The battery lithium deposition detection method according to claim 1, wherein: The step of obtaining a second spectrum envelope area corresponding to the internal stress of the battery during the charging process includes: Obtaining actual internal stress of the battery during charging; Acquire the second spectrum envelope area corresponding to the internal stress of the battery based on the actual internal stress and the mapping relationship; The mapping relationship includes a corresponding relationship between the internal stress of the battery and the envelope area of ​​the spectrum signal under the internal stress.

3. The battery lithium deposition detection method according to claim 2, wherein: Before obtaining the actual internal stress of the battery during the charging process, the battery lithium deposition detection method further includes: Charging the battery at a preset rate, and acquiring a second optical signal of the battery during the charging process at the preset rate; Acquire a second spectrum signal corresponding to the second optical signal, and record a wavelength change and an envelope area change of the cladding region in the second spectrum signal; Acquire stress data of the battery based on the wavelength variation in the second spectral signal and a stress analysis matrix of the battery; Fitting is performed based on the stress data and the envelope area change to obtain the mapping relationship.

4. The battery lithium deposition detection method according to claim 2 or 3, wherein: The step of obtaining the actual internal stress of the battery during the charging process includes: Acquiring a wavelength change of the first spectral signal; The actual internal stress of the battery during the charging process is obtained based on the wavelength change in the first spectral signal and the stress analysis matrix of the battery.

5. The battery lithium deposition detection method according to any one of claims 1 to 4, wherein: The step of determining the lithium plating detection result of the battery based on the first spectrum envelope area includes: In response to the first spectrum envelope area being greater than or equal to the corresponding first preset envelope area threshold, determining that lithium deposition has occurred in the battery; In response to the first spectral envelope area being less than the corresponding first preset envelope area threshold and greater than or equal to the corresponding second preset envelope area threshold, it is determined that the battery has a risk of lithium plating, wherein the second preset envelope area threshold is less than the first preset envelope area threshold.

6. The battery lithium deposition detection method according to any one of claims 1 to 4, wherein: The step of determining the lithium plating detection result of the battery based on the first spectrum envelope area includes: performing normalization processing on the first spectrum envelope area; In response to the normalized first spectrum envelope area being greater than or equal to the corresponding first preset percentage threshold, determining that lithium deposition has occurred in the battery; In response to the normalized first spectral envelope area being less than the corresponding first preset percentage threshold and greater than or equal to the corresponding second preset percentage threshold, it is determined that the battery has a risk of lithium plating, wherein the second preset percentage threshold is less than the first preset percentage threshold.

7. The battery lithium deposition detection method according to claim 5 or 6, wherein: After the step of determining the lithium deposition detection result of the battery based on the first spectrum envelope area, the battery lithium deposition detection method further includes: In response to the battery having lithium deposition or having a risk of lithium deposition during charging, the charging strategy of the battery is adjusted.

8. The battery lithium deposition detection method according to claim 7, wherein: The step of adjusting the charging strategy of the battery includes: In response to the lithium deposition test result indicating that there is a risk of lithium deposition, reducing the charging current of the battery to charge the battery until the lithium deposition test result of the battery indicates that there is no risk of lithium deposition; In response to the lithium deposition detection result indicating that lithium deposition has occurred, charging of the battery is stopped, the battery is reversely discharged, and the charging current of the battery is reduced when the battery is charged after the reverse discharge.

9. A battery, wherein: It includes a battery body, at least one optical fiber sensor and a control module, wherein the detection part of the optical fiber sensor is arranged inside the battery body, wherein the optical fiber sensor is configured to output an optical signal during the charging process of the battery, and the control module is connected to the optical fiber sensor; wherein the control module is used to obtain a first spectral signal corresponding to the optical signal, and obtain the total envelope area of ​​the cladding region of the first spectral signal of the battery during the charging process based on the first spectral signal; obtain a second spectral envelope area corresponding to the internal stress of the battery during the charging process; calculate the difference between the total envelope area and the second spectral envelope area to obtain the first spectral envelope area; and determine the lithium plating detection result of the battery based on the first spectral envelope area.

10. The battery according to claim 9, wherein The optical fiber sensor includes at least one grating part and a transmission optical fiber connected to the grating part, and the grating part is arranged inside the battery body.

11. The battery according to claim 10, wherein The input end and the output end of the transmission optical fiber are both arranged outside the battery body, and the middle connection part between the input end and the output end of the transmission optical fiber is arranged inside the battery body.

12. The battery according to claim 10, wherein A reflective layer is arranged inside the battery body, the input end of the transmission optical fiber is arranged outside the battery body, and the output end of the transmission optical fiber is arranged inside the battery body and abuts against the reflective layer, wherein the reflective layer is used to reflect the initial light signal incident from the input end so that the output light signal is transmitted outward from the input end.

13. The battery according to claim 11, wherein The transmission optical fiber comprises a core and a cladding, and the diameter of the cladding is set to be between 25 μm and 125 μm.

14. The battery according to claim 11, wherein The transmission optical fiber comprises a core and a cladding, and the diameter of the cladding is set to be between 50 μm and 100 μm.

15. The battery according to claim 11, wherein The length of the grating portion is set to be between 0.3 cm and 1.2 cm.

16. The battery according to claim 11, wherein The length of the grating portion is set to be between 0.5 cm and 1 cm.

17. The battery according to any one of claims 9 to 16, wherein: The control module includes an optical demodulation module and a battery management module. The optical demodulation module is connected to the optical fiber sensor and is used to modulate the optical signal output by the optical fiber sensor during the charging process of the battery to obtain a first spectrum signal; the battery management module is connected to the optical demodulation module and is used to obtain the total envelope area of ​​the cladding region of the first spectrum signal of the battery during the charging process based on the first spectrum signal; and obtain the second spectrum envelope area corresponding to the internal stress of the battery during the charging process; Calculating a difference between the total envelope area and the second spectrum envelope area to obtain a first spectrum envelope area; A lithium plating detection result of the battery is determined based on the first spectral envelope area.

18. A battery system, wherein: It comprises a battery and a charge and discharge control module as described in any one of claims 9 to 17, wherein the charge and discharge control module is connected to the control module and the battery, and is used to adjust the charging strategy of the battery in response to the occurrence of lithium deposition or the risk of lithium deposition in the battery during charging.

19. An electrical device, wherein: A battery system comprising the battery system of claim 18.

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