Method and device for detecting lithium precipitation of lithium iron phosphate battery

Abstract

The invention belongs to the field of safety of energy storage batteries, and particularly relates to a method and a device for detecting lithium precipitation of a lithium iron phosphate battery. The method comprises the following steps: acquiring a central wavelength signal of a grating sensor pre-embedded in a negative electrode of a lithium iron phosphate battery; determining the strain of the negative electrode of the lithium iron phosphate battery based on the central wavelength signal; and comparing the strain of the negative electrode of the lithium iron phosphate battery with a strain threshold value to obtain a lithium precipitation detection result of the lithium iron phosphate battery. The strain condition of the negative electrode of the lithium iron phosphate battery can be detected on line through the pre-embedded optical fiber, and the lithium precipitation condition of the lithium iron phosphate battery can be reflected based on the strain of the negative electrode of the lithium iron phosphate battery; and early warning can be carried out in advance, safety risks caused by battery short circuit and thermal runaway are avoided in time, and the accident risk of the lithium iron phosphate battery cabin is reduced.

Description

Technical Field

[0001] This invention belongs to the field of energy storage battery safety, specifically relating to a method and apparatus for detecting lithium plating in lithium iron phosphate batteries. Background Technology

[0002] New energy storage is an important technical support and basic equipment for building new power systems. Electrochemical energy storage, represented by lithium-ion batteries, has comprehensive advantages in terms of technology, economy, industry, and market. In recent years, the installed capacity of electrochemical energy storage has grown rapidly. However, due to the immaturity of energy storage technology and equipment, and the imperfect technical management system, the application and technical management of electrochemical energy storage are highly professional, special, and complex. The construction process of energy storage power stations is rough, and the safety and quality control measures throughout the process are inadequate, making it difficult to meet the requirements of relevant standards and management specifications. The parameters, status, and output boundaries of the put-in energy storage power stations are uncertain, highlighting safety risks and hidden dangers, and fire accidents occur from time to time.

[0003] In recent years, the energy storage sector has issued a series of regulatory documents directly related to electrochemical energy storage power stations, explicitly requiring further strengthening of safety and quality management, and enhancing risk monitoring and early warning for safe operation. Lithium iron phosphate (LFP) batteries contain a large number of individual cells, which can easily lead to inconsistencies and create a "weak link" in the battery structure. As these inconsistencies worsen, overcharging (or slight overcharging) of some cells can easily cause lithium deposition on the graphite anode. Furthermore, high-power charging and discharging or uneven internal temperature distribution in lithium-ion batteries can also cause abnormal lithium-ion transport, resulting in lithium deposition sites. Therefore, lithium dendrite formation is a major cause of internal short circuits and safety accidents in batteries.

[0004] Conventional lithium plating detection methods for batteries, such as infrared and electron beam imaging, are unsatisfactory in battery detection due to their lack of penetration, insufficient speed and accuracy. Existing in-situ analytical characterization techniques, including X-ray imaging, neutron diffraction and electrochemical analysis, also have certain problems. None of the existing detection technologies can achieve online monitoring and early warning. Summary of the Invention

[0005] The purpose of this invention is to provide a method and apparatus for detecting lithium deposition in lithium iron phosphate batteries, so as to solve the technical problem that existing detection technologies cannot perform online detection and early warning of the lithium dendrite deposition process in batteries.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for detecting lithium plating in lithium iron phosphate batteries, comprising: Acquire the center wavelength signal of the grating sensor pre-embedded in the negative electrode of the lithium iron phosphate battery; Strain of the negative electrode of lithium iron phosphate battery determined based on center wavelength signal; The lithium plating detection results of lithium iron phosphate batteries are obtained by comparing the strain and strain threshold of the negative electrode.

[0007] A further improvement of the present invention is that the step of determining the strain of the negative electrode of the lithium iron phosphate battery based on the center wavelength signal specifically includes: obtaining the offset of the center wavelength by comparing the center wavelength signal with the initial wavelength; and determining the strain of the negative electrode of the lithium iron phosphate battery based on the offset of the center wavelength.

[0008] A further improvement of the present invention is that: in the step of determining the strain of the lithium iron phosphate battery negative electrode based on the offset of the center wavelength: the strain of the corresponding lithium iron phosphate battery negative electrode is found in the pre-established center wavelength offset-strain curve based on the offset of the center wavelength.

[0009] A further improvement of the present invention is that, in the step of obtaining the lithium plating detection result of the lithium iron phosphate battery by comparing the strain of the negative electrode of the lithium iron phosphate battery with the strain threshold, the strain of the negative electrode of the lithium iron phosphate battery is compared with the strain threshold, and a lithium plating warning signal is issued if the strain is greater than the strain threshold.

[0010] A further improvement of this invention is that the negative electrode of the lithium iron phosphate battery is a graphite negative electrode.

[0011] A further improvement of the present invention is that it also includes: Acquire the optical signal from the fiber optic sensor embedded in the negative electrode of the lithium iron phosphate battery; obtain the temperature signal of the negative electrode of the lithium iron phosphate battery based on the optical signal; In the step of obtaining the lithium plating detection result of lithium iron phosphate battery by comparing the strain of the negative electrode of lithium iron phosphate battery with the strain threshold, the strain of the negative electrode of lithium iron phosphate battery is compared with the strain threshold. When the strain is greater than the strain threshold and the temperature signal is greater than the temperature threshold, a lithium plating warning signal is issued.

[0012] Secondly, the present invention provides a lithium iron phosphate battery lithium plating detection device, comprising: The acquisition module is used to acquire the center wavelength signal of the grating sensor embedded in the negative electrode of the lithium iron phosphate battery; The determination module is used to determine the strain of the negative electrode of the lithium iron phosphate battery based on the center wavelength signal; The early warning module is used to obtain the lithium plating detection results of lithium iron phosphate batteries by comparing the strain of the negative electrode with the strain threshold.

[0013] A further improvement of the present invention is that the step of determining the strain of the negative electrode of the lithium iron phosphate battery based on the center wavelength signal specifically includes: obtaining the offset of the center wavelength based on the comparison between the center wavelength signal and the initial wavelength; and determining the strain of the negative electrode of the lithium iron phosphate battery based on the offset of the center wavelength.

[0014] A further improvement of the present invention is that, in the step of determining the strain of the lithium iron phosphate battery negative electrode based on the offset of the center wavelength, the corresponding strain of the lithium iron phosphate battery negative electrode is found in the pre-established center wavelength offset-strain curve based on the offset of the center wavelength.

[0015] A further improvement of the present invention is that, in the step of obtaining the lithium plating detection result of the lithium iron phosphate battery based on the comparison of the strain of the negative electrode of the lithium iron phosphate battery with the strain threshold, the strain of the negative electrode of the lithium iron phosphate battery is compared with the strain threshold, and a lithium plating warning signal is issued if the strain is greater than the strain threshold.

[0016] A further improvement of this invention is that the negative electrode of the lithium iron phosphate battery is a graphite negative electrode.

[0017] A further improvement of the present invention is that it also includes: The temperature module is used to acquire the optical signal from the fiber optic sensor embedded in the negative electrode of the lithium iron phosphate battery; and to obtain the temperature signal of the negative electrode of the lithium iron phosphate battery based on the optical signal. In the step of obtaining the lithium plating detection result of lithium iron phosphate battery based on the comparison of strain of the negative electrode of lithium iron phosphate battery with strain threshold, the early warning module compares the strain of the negative electrode of lithium iron phosphate battery with strain threshold. When the strain is greater than strain threshold and the temperature signal is greater than temperature threshold, a lithium plating early warning signal is issued.

[0018] Thirdly, the present invention provides an electronic device, including a processor and a memory, wherein the processor is used to execute a computer program stored in the memory to implement the aforementioned lithium iron phosphate battery lithium plating detection method.

[0019] In a fourth aspect, the present invention provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores at least one instruction, which, when executed by a processor, implements the lithium iron phosphate battery lithium plating detection method.

[0020] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for detecting lithium plating in lithium iron phosphate batteries, comprising: acquiring the center wavelength signal of a grating sensor pre-embedded in the negative electrode of the lithium iron phosphate battery; determining the strain of the negative electrode of the lithium iron phosphate battery based on the center wavelength signal; and obtaining the lithium plating detection result of the lithium iron phosphate battery by comparing the strain of the negative electrode of the lithium iron phosphate battery with a strain threshold. This invention enables online detection of the strain of the negative electrode of the lithium iron phosphate battery through pre-embedded optical fiber. The strain of the negative electrode of the lithium iron phosphate battery can reflect the lithium plating status of the lithium iron phosphate battery; and it can provide early warning, timely avoiding safety risks caused by battery short circuits and thermal runaway, and reducing the accident risk of the lithium iron phosphate battery compartment.

[0021] Furthermore, in this invention, an optical fiber sensor is simultaneously installed at the negative electrode of the lithium iron phosphate battery to acquire the temperature signal of the negative electrode. When lithium is deposited in the lithium iron phosphate battery, the temperature of the negative electrode will rise. By monitoring the temperature signal, it can be further confirmed whether there is a risk of lithium deposition. Combining the stress signal and the temperature signal can more accurately monitor the risk of lithium deposition and provide accurate early warning. Attached Figure Description

[0022] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This image shows the morphology of lithium dendrite growth during the charging process. Figure 2 This is a schematic flowchart of a lithium iron phosphate battery lithium plating detection method according to an embodiment of the present invention; Figure 3 This is a schematic flowchart of a lithium iron phosphate battery lithium plating detection method according to another embodiment of the present invention; Figure 4 This is a schematic diagram of a lithium iron phosphate battery lithium plating detection device according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of an electronic device according to the present invention. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0024] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this invention is for describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0025] The applicant's research found that graphite, as the most commonly used negative electrode material in lithium iron phosphate batteries, exhibits significant changes in mechanical parameters during the lithium plating process. Therefore, using mechanical stress signals to detect lithium plating in lithium iron phosphate batteries is feasible. This invention primarily studies lithium plating characteristics by measuring the strain of the lithium iron phosphate battery negative electrode. By embedding a grating sensor inside the graphite material and studying the shift in its center wavelength, the strain change of the graphite negative electrode can be obtained, thereby monitoring the lithium plating process.

[0026] This invention provides a method for detecting lithium plating in lithium iron phosphate batteries, comprising the following steps: An in-situ glass battery is assembled by embedding a grating sensor inside the graphite negative electrode of a lithium iron phosphate battery. The in-situ glass battery uses lithium iron phosphate as the positive electrode material and graphite or metallic lithium as the negative electrode material. The battery uses an electrolyte of appropriate concentration. The tail wire of the embedded grating sensor is led out through a small hole at the top of the battery and connected to an optical performance monitoring module for measuring wavelength data. The in-situ glass battery casing is made of transparent glass to facilitate optical observation. The fiber optic measurement section is implemented by an optical performance monitoring module and a host computer. The optical performance monitoring module is equipped with several measurement channels and is suitable for signal demodulation modules that detect dynamic stress in sensing systems. The module adopts photonic integration technology. The wavelength and spectrum data of the grating under test are reported to the host computer through the network port.

[0027] The optical microscopy observation section consists of an optical long focal length microscope and an auxiliary light source. The focal length is changed by adjusting the distance between the lens and the battery under test, and the brightness of the output image is improved by adjusting the intensity of the auxiliary light source. Finally, the dynamic process of lithium plating on the negative electrode of the in-situ glass battery is presented in real time on the monitor.

[0028] By setting up cyclic experiments and observing the results, it was found that the growth of lithium dendrites leads to an increase in the internal stress of the negative electrode, thereby causing an increase in the center wavelength signal output by the grating sensor. Furthermore, the larger the dendrites and the greater the lithium deposition, the greater the change in the center wavelength of the optical fiber. Through cyclic experiments, the correlation curve between strain and lithium deposition area was obtained. The center wavelength shift is the difference between the center wavelength signal of the grating sensor and the initial wavelength. The initial wavelength is the initial wavelength of the grating sensor before lithium deposition occurs in the initial experimental state. The increase in internal stress of the negative electrode due to lithium dendrite growth causes an increase in the center wavelength signal output by the grating sensor, resulting in an increase in the center wavelength shift. The strain of the negative electrode is calculated from the center wavelength shift. Please refer to [link to relevant documentation]. Figure 1 As shown, the lithium plating area was observed using an optical long-focal-length microscope, and a correlation curve between strain and lithium plating area was created. An increase in the lithium plating area can lead to risks such as short circuits and thermal runaway in the battery. Three strain thresholds were set based on the strain corresponding to the lithium plating area.

[0029] In actual use, the center wavelength signal of the grating sensor embedded in the negative electrode of the lithium iron phosphate battery is monitored in real time, the offset of the center wavelength is calculated, the strain of the negative electrode of the lithium iron phosphate battery is determined based on the offset of the center wavelength, and the strain is compared with the three-level strain threshold. When the strain value exceeds the strain threshold of the corresponding level, the corresponding level of warning signal is issued.

[0030] The method of this invention can realize in-situ monitoring of internal strain (10 micro-strain levels) of lithium iron phosphate battery electrodes and can observe lithium plating images in real time.

[0031] Please see Figure 2As shown, this embodiment of the invention provides a method for detecting lithium plating in lithium iron phosphate batteries, comprising: S100: Obtain the center wavelength signal of the grating sensor embedded in the negative electrode of the lithium iron phosphate battery; S200, Determining the strain of the negative electrode of a lithium iron phosphate battery based on the center wavelength signal; S300: Based on the comparison of strain and strain threshold of the negative electrode of lithium iron phosphate battery, the lithium plating detection results of lithium iron phosphate battery are obtained.

[0032] In one specific embodiment, the step of determining the strain of the lithium iron phosphate battery negative electrode based on the center wavelength signal specifically includes: obtaining the offset of the center wavelength by comparing the center wavelength signal with the initial wavelength; and determining the strain of the lithium iron phosphate battery negative electrode based on the offset of the center wavelength.

[0033] In one specific embodiment, in the step of determining the strain of the lithium iron phosphate battery negative electrode based on the offset of the center wavelength: the strain of the corresponding lithium iron phosphate battery negative electrode is found in the pre-established center wavelength offset-strain curve based on the offset of the center wavelength.

[0034] In one specific embodiment, in the step of obtaining the lithium plating detection result of the lithium iron phosphate battery by comparing the strain of the negative electrode of the lithium iron phosphate battery with a strain threshold, the strain of the negative electrode of the lithium iron phosphate battery is compared with a strain threshold, and a lithium plating warning signal is issued if the strain is greater than the strain threshold.

[0035] In one specific embodiment, the negative electrode of the lithium iron phosphate battery is a graphite negative electrode.

[0036] Please see Figure 3 As shown, this embodiment of the invention provides a method for detecting lithium plating in lithium iron phosphate batteries, comprising: S101. Obtain the center wavelength signal of the grating sensor embedded in the negative electrode of the lithium iron phosphate battery; obtain the optical signal of the fiber optic sensor embedded in the negative electrode of the lithium iron phosphate battery. S201. Determine the strain of the negative electrode of the lithium iron phosphate battery based on the center wavelength signal; obtain the temperature signal of the negative electrode of the lithium iron phosphate battery based on the optical signal; S301. Based on the comparison between the strain and strain threshold of the negative electrode of lithium iron phosphate battery, a lithium plating warning signal is issued when the strain is greater than the strain threshold and the temperature signal is greater than the temperature threshold.

[0037] In one specific implementation, the temperature threshold is the normal operating temperature of the lithium iron phosphate battery negative electrode +3°C; the temperature of the corresponding area is monitored simultaneously by a fiber optic sensor, and if the abnormal strain area is accompanied by a sudden temperature rise, it is further confirmed that lithium plating has occurred (the exothermic side reaction of lithium plating leads to local temperature rise).

[0038] Please see Figure 4As shown, an embodiment of the present invention provides a lithium iron phosphate battery lithium plating detection device, comprising: The acquisition module is used to acquire the center wavelength signal of the grating sensor embedded in the negative electrode of the lithium iron phosphate battery; The determination module is used to determine the strain of the negative electrode of the lithium iron phosphate battery based on the center wavelength signal; The early warning module is used to obtain the lithium plating detection results of lithium iron phosphate batteries by comparing the strain of the negative electrode with the strain threshold.

[0039] In one specific embodiment, the step of determining the strain of the lithium iron phosphate battery negative electrode based on the center wavelength signal specifically includes: obtaining the offset of the center wavelength by comparing the center wavelength signal with the initial wavelength; and determining the strain of the lithium iron phosphate battery negative electrode based on the offset of the center wavelength.

[0040] In one specific embodiment, in the step of determining the strain of the lithium iron phosphate battery negative electrode based on the offset of the center wavelength, the corresponding strain of the lithium iron phosphate battery negative electrode is found in the pre-established center wavelength offset-strain curve based on the offset of the center wavelength.

[0041] In one specific implementation, in the step of obtaining the lithium plating detection result of the lithium iron phosphate battery based on the comparison between the strain of the negative electrode of the lithium iron phosphate battery and the strain threshold, the strain of the negative electrode of the lithium iron phosphate battery is compared with the strain threshold, and a lithium plating warning signal is issued if the strain is greater than the strain threshold.

[0042] In one specific embodiment, the negative electrode of the lithium iron phosphate battery is a graphite negative electrode.

[0043] This invention provides a lithium iron phosphate battery lithium plating detection device, comprising: The acquisition module is used to acquire the center wavelength signal of the grating sensor embedded in the negative electrode of the lithium iron phosphate battery; and to acquire the optical signal of the fiber optic sensor embedded in the negative electrode of the lithium iron phosphate battery. The determination module is used to determine the strain of the lithium iron phosphate battery negative electrode based on the center wavelength signal; and to obtain the temperature signal of the lithium iron phosphate battery negative electrode based on the optical signal. The early warning module is used to compare the strain of the negative electrode of the lithium iron phosphate battery with a strain threshold. When the strain is greater than the strain threshold and the temperature signal is greater than the temperature threshold, a lithium plating early warning signal is issued.

[0044] Please see Figure 5 As shown, this embodiment of the invention provides an electronic device 100 for implementing a lithium iron phosphate battery lithium plating detection method; the electronic device 100 includes a memory 101, at least one processor 102, a computer program 103 stored in the memory 101 and executable on the at least one processor 102, and at least one communication bus 104.

[0045] The memory 101 can be used to store the computer program 103. The processor 102 implements the steps of the lithium iron phosphate battery lithium plating detection method described in the embodiment by running or executing the computer program stored in the memory 101 and calling the data stored in the memory 101. The memory 101 may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the electronic device 100 (such as audio data), etc. In addition, the memory 101 may include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other non-volatile solid-state storage device.

[0046] The at least one processor 102 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 102 may be a microprocessor or any conventional processor. The processor 102 is the control center of the electronic device 100, connecting various parts of the electronic device 100 via various interfaces and lines.

[0047] The memory 101 in the electronic device 100 stores multiple instructions to implement a lithium iron phosphate battery lithium plating detection method, and the processor 102 can execute the multiple instructions to achieve the following: Acquire the center wavelength signal of the grating sensor pre-embedded in the negative electrode of the lithium iron phosphate battery; Strain of the negative electrode of lithium iron phosphate battery determined based on center wavelength signal; The lithium plating detection results of lithium iron phosphate batteries are obtained by comparing the strain and strain threshold of the negative electrode.

[0048] If the modules / units integrated in the electronic device 100 are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, and a read-only memory (ROM).

[0049] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0050] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0051] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0052] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for detecting lithium plating in lithium iron phosphate batteries, characterized in that, include: Acquire the center wavelength signal of the grating sensor pre-embedded in the negative electrode of the lithium iron phosphate battery; Strain of the negative electrode of lithium iron phosphate battery determined based on center wavelength signal; The lithium plating detection results of lithium iron phosphate batteries are obtained by comparing the strain and strain threshold of the negative electrode.

2. The method for detecting lithium plating in lithium iron phosphate batteries according to claim 1, characterized in that, The step of determining the strain of the lithium iron phosphate battery negative electrode based on the center wavelength signal specifically includes: obtaining the offset of the center wavelength by comparing the center wavelength signal with the initial wavelength; and determining the strain of the lithium iron phosphate battery negative electrode based on the offset of the center wavelength.

3. The method for detecting lithium plating in lithium iron phosphate batteries according to claim 2, characterized in that, In the step of determining the strain of the lithium iron phosphate battery negative electrode based on the offset of the center wavelength: the strain of the corresponding lithium iron phosphate battery negative electrode is found in the pre-established center wavelength offset-strain curve based on the offset of the center wavelength.

4. The lithium iron phosphate battery lithium plating detection method according to claim 2, characterized in that, In the step of obtaining the lithium plating detection result of lithium iron phosphate battery by comparing the strain of the negative electrode of lithium iron phosphate battery with the strain threshold, the strain of the negative electrode of lithium iron phosphate battery is compared with the strain threshold, and a lithium plating warning signal is issued if the strain is greater than the strain threshold.

5. The method for detecting lithium plating in lithium iron phosphate batteries according to claim 1, characterized in that, The negative electrode of the lithium iron phosphate battery is a graphite negative electrode.

6. The method for detecting lithium plating in lithium iron phosphate batteries according to claim 2, characterized in that, Also includes: Acquire the optical signal from the fiber optic sensor embedded in the negative electrode of the lithium iron phosphate battery; obtain the temperature signal of the negative electrode of the lithium iron phosphate battery based on the optical signal; In the step of obtaining the lithium plating detection result of lithium iron phosphate battery by comparing the strain of the negative electrode of lithium iron phosphate battery with the strain threshold, the strain of the negative electrode of lithium iron phosphate battery is compared with the strain threshold. When the strain is greater than the strain threshold and the temperature signal is greater than the temperature threshold, a lithium plating warning signal is issued.

7. A lithium iron phosphate battery lithium plating detection device, characterized in that, include: The acquisition module is used to acquire the center wavelength signal of the grating sensor embedded in the negative electrode of the lithium iron phosphate battery; The determination module is used to determine the strain of the negative electrode of the lithium iron phosphate battery based on the center wavelength signal; The early warning module is used to obtain the lithium plating detection results of lithium iron phosphate batteries by comparing the strain of the negative electrode with the strain threshold.

8. The lithium iron phosphate battery lithium plating detection device according to claim 7, characterized in that, The steps for determining the strain of the lithium iron phosphate battery negative electrode based on the center wavelength signal include: obtaining the offset of the center wavelength by comparing the center wavelength signal with the initial wavelength; and determining the strain of the lithium iron phosphate battery negative electrode based on the offset of the center wavelength.

9. The lithium iron phosphate battery lithium plating detection device according to claim 8, characterized in that, In the step of determining the strain of the lithium iron phosphate battery negative electrode based on the offset of the center wavelength, the corresponding strain of the lithium iron phosphate battery negative electrode is found in the pre-established center wavelength offset-strain curve based on the offset of the center wavelength.

10. The lithium iron phosphate battery lithium plating detection device according to claim 8, characterized in that, In the step of obtaining the lithium plating detection result of the lithium iron phosphate battery based on the comparison between the strain of the negative electrode of the lithium iron phosphate battery and the strain threshold, the early warning module compares the strain of the negative electrode of the lithium iron phosphate battery with the strain threshold. If the strain exceeds the strain threshold, a lithium plating early warning signal is issued.

11. The lithium iron phosphate battery lithium plating detection device according to claim 7, characterized in that, The negative electrode of the lithium iron phosphate battery is a graphite negative electrode.

12. The lithium iron phosphate battery lithium plating detection device according to claim 8, characterized in that, Also includes: The temperature module is used to acquire the optical signal from the fiber optic sensor embedded in the negative electrode of the lithium iron phosphate battery; and to obtain the temperature signal of the negative electrode of the lithium iron phosphate battery based on the optical signal. In the step of obtaining the lithium plating detection result of lithium iron phosphate battery based on the comparison of strain of the negative electrode of lithium iron phosphate battery with strain threshold, the early warning module compares the strain of the negative electrode of lithium iron phosphate battery with strain threshold. When the strain is greater than strain threshold and the temperature signal is greater than temperature threshold, a lithium plating early warning signal is issued.

13. An electronic device, characterized in that, It includes a processor and a memory, the processor being used to execute a computer program stored in the memory to implement a lithium iron phosphate battery lithium plating detection method as described in any one of claims 1 to 6.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one instruction, which, when executed by a processor, implements a lithium iron phosphate battery lithium plating detection method as described in any one of claims 1 to 6.

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