Voltage detection device, voltage detection method, and battery system

Abstract

The application relates to the technical field of batteries and discloses a voltage detection device, a voltage detection method and a battery system, the voltage detection device comprising an optical fiber with a grating, a wavelength detection device and a fiber battery; the fiber battery comprising a negative electrode conductive layer, a negative electrode material layer, an electrolyte layer, a positive electrode material layer and a positive electrode conductive layer; the fiber battery is arranged at a position corresponding to the grating, and the negative electrode conductive layer, the negative electrode material layer, the electrolyte layer, the positive electrode material layer and the positive electrode conductive layer sequentially coat the grating from inside to outside; the wavelength detection device is connected with one end of the optical fiber and is used for detecting the reflected wavelength of the grating. Since the voltage detection device can detect the voltage of a single battery in a lithium ion battery pack, the problem that there are few devices capable of being applied to lithium ion battery packs to detect the voltage of each single battery in the prior art can be solved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically to a voltage detection device, a voltage detection method, and a battery system. Background Technology

[0002] With the rapid development of the new energy industry, lithium-ion batteries have been widely used in various fields, including portable electronic products, electric vehicles, and aerospace equipment.

[0003] In lithium-ion battery packs, monitoring the voltage of each individual cell is crucial. By measuring the voltage of each cell, the operating state of each individual cell can be determined, and the overall voltage of the battery pack can be calculated by summing the voltages. Therefore, when an abnormal voltage occurs in the battery pack, the individual cell with the abnormal voltage can be accurately identified by analyzing the voltage readings of each cell, allowing for timely remedial measures.

[0004] However, there is still a lack of devices that can be applied to lithium-ion battery packs to detect the voltage of individual cells. Summary of the Invention

[0005] The purpose of this invention is to overcome the lack of existing devices that can be applied to lithium-ion battery packs to detect the voltage of individual cells, and to provide a voltage detection device, a voltage detection method, and a battery system.

[0006] To achieve the above objectives, the first aspect of the present invention provides a voltage detection device, the voltage detection device comprising an optical fiber with a grating, a wavelength detection device, and a fiber battery;

[0007] The fiber battery includes a negative electrode conductive layer, a negative electrode material layer, an electrolyte layer, a positive electrode material layer, and a positive electrode conductive layer.

[0008] The fiber battery is positioned at the location corresponding to the grating;

[0009] The negative electrode conductive layer, the negative electrode material layer, the electrolyte layer, the positive electrode material layer, and the positive electrode conductive layer sequentially cover the grating from the inside out;

[0010] The wavelength detection device is connected to one end of the optical fiber and is used to detect the reflected wavelength of the grating.

[0011] In this embodiment of the application, the grating is a Bragg grating.

[0012] In this embodiment, the optical fiber has multiple gratings, and the voltage detection device includes multiple fiber cells;

[0013] The multiple fiber batteries are respectively positioned at the corresponding positions of each grating.

[0014] In this embodiment of the application, any two gratings among the plurality of gratings have different initial reflection wavelengths, and the initial reflection wavelength is the reflection wavelength corresponding to the grating when it has not undergone deformation.

[0015] In this embodiment of the application, in the fiber battery, the negative electrode conductive layer, the negative electrode material layer, the electrolyte layer, the positive electrode material layer, and the positive electrode conductive layer are sequentially stacked.

[0016] The negative electrode conductive layer completely covers the grating, one end of the negative electrode conductive layer exposes the negative electrode material layer, the electrolyte layer completely covers the negative electrode material layer, the positive electrode material layer covers at least a portion of the electrolyte layer, and the positive electrode conductive layer completely covers the positive electrode material layer.

[0017] In this embodiment, the negative electrode conductive layer is a copper layer, and the positive electrode conductive layer is an aluminum layer.

[0018] In this embodiment of the application, the negative electrode material layer is obtained by coating the surface of the negative electrode conductive layer with a first slurry, wherein the first slurry includes a negative electrode material, a first conductive agent, and a first binder;

[0019] The electrolyte layer is obtained by coating the surface of the negative electrode material layer with a second slurry, the second slurry comprising polyethylene oxide and / or polyvinylidene fluoride;

[0020] The positive electrode material layer is obtained by coating the surface of the electrolyte layer with a third slurry, the third slurry comprising a positive electrode material, a second conductive agent, and a second binder.

[0021] A second aspect of the present invention provides a voltage detection method, the detection method being used to detect the voltage of a target device using a voltage detection device provided in the first aspect, the detection method comprising:

[0022] The negative electrode conductive layer in the fiber battery is connected to the negative electrode of the target device, and the positive electrode conductive layer in the fiber battery is connected to the positive electrode of the target device.

[0023] Obtain the reflection wavelength of the grating corresponding to the fiber cell;

[0024] The voltage of the target device is determined based on the reflected wavelength.

[0025] In this embodiment of the application, determining the voltage of the target device based on the reflected wavelength includes:

[0026] Based on the reflected wavelength, the degree of deformation occurring in the region on the optical fiber corresponding to the grating is determined, and the voltage of the target device is determined based on the degree of deformation.

[0027] A third aspect of the present invention provides a battery system, the system comprising a lithium-ion battery pack and a voltage detection device provided in the first aspect;

[0028] The lithium-ion battery pack includes multiple individual cells, and the voltage detection device includes multiple fiber cells.

[0029] Each individual cell is connected to each fiber cell in a one-to-one correspondence. The positive electrode of the individual cell is connected to the positive conductive layer of the fiber cell, and the negative electrode of the individual cell is connected to the negative conductive layer of the fiber cell.

[0030] The voltage detection device described above includes an optical fiber with a grating, a wavelength detection device, and a fiber battery. The fiber battery includes a negative electrode conductive layer, a negative electrode material layer, an electrolyte layer, a positive electrode material layer, and a positive electrode conductive layer. The fiber battery is disposed at a position corresponding to the grating. The negative electrode conductive layer, the negative electrode material layer, the electrolyte layer, the positive electrode material layer, and the positive electrode conductive layer sequentially cover the grating from the inside out. The wavelength detection device is connected to one end of the optical fiber and is used to detect the reflected wavelength of the grating. Since the voltage detection device provided in this application embodiment can detect the voltage of individual cells in a lithium-ion battery pack, it solves the problem of the lack of existing devices applicable to lithium-ion battery packs for detecting the voltage of individual cells.

[0031] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0032] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:

[0033] Figure 1 The schematic diagram illustrates a structural schematic of a voltage detection device according to an embodiment of this application;

[0034] Figure 2 The schematic diagram illustrates a structural schematic of a fiber battery according to an embodiment of this application;

[0035] Figure 3 The diagram illustrates the wavelength variation of the grating, the volume variation of the fiber cell, and the correspondence with the state of charge according to an embodiment of this application.

[0036] Figure 4 The schematic diagram illustrates a structural schematic of a battery system according to an embodiment of this application;

[0037] Figure 5 The illustration shows a schematic flowchart of a voltage detection method according to an embodiment of this application.

[0038] Explanation of reference numerals in the attached figures

[0039] 100—Voltage detection device; 101—Optical fiber; 1011—Grate; 102—Wavelength detection device; 103—Fiber cell; 1031—Negative electrode conductive layer; 1032—Negative electrode material layer; 1033—Electrolyte layer; 1034—Positive electrode material layer; 1035—Positive electrode conductive layer. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0041] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0042] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0043] As described in the background section, detecting the voltage of each individual cell in a lithium-ion battery pack is crucial. By detecting the voltage of each individual cell, the operating state of each cell can be obtained, and the overall voltage of the battery pack can be calculated by summing the voltages. Therefore, when the battery pack voltage becomes abnormal, the individual cell with the abnormal voltage can be accurately identified based on the detection results of the individual cell voltages, allowing for timely remedial measures. In practical applications, a battery management system (BMS) is generally used to detect the voltage of each individual cell. Existing BMS systems often employ Application-Specific Integrated Circuit (ASIC) chip technology to acquire the voltage of each individual cell. However, due to factors such as monopolies, the application cost of this chip technology is high. In other words, devices currently available for detecting the voltage of individual cells in lithium-ion battery packs are relatively scarce.

[0044] In response to this, such as Figure 1 As shown, one embodiment of this application provides a voltage detection device 100, which includes an optical fiber 101 with a grating 1011, a wavelength detection device 102, and a fiber battery 103. The fiber battery 103 includes a negative electrode conductive layer 1031, a negative electrode material layer 1032, an electrolyte layer 1033, a positive electrode material layer 1034, and a positive electrode conductive layer 1035. The fiber battery 103 is disposed at a position corresponding to the grating 1011. The negative electrode conductive layer 1031, the negative electrode material layer 1032, the electrolyte layer 1033, the positive electrode material layer 1034, and the positive electrode conductive layer 1035 sequentially cover the grating 1011 from the inside out. The wavelength detection device 102 is connected to one end of the optical fiber 101 and is used to detect the reflected wavelength of the grating 1011.

[0045] The grating 1011 can be etched onto the optical fiber 101. The grating 1011 can reflect light, and the wavelength detection device 102 can be used to detect the reflected wavelength of the grating 1011 in real time. Furthermore, the wavelength detection device 102 can monitor changes in the reflected wavelength of the grating 1011.

[0046] In practical applications, the area on the optical fiber 101 where the grating 1011 is set can be called the grating region, and the range of the grating region completely covers the grating 1011. Then, the fiber cell 103 is set at the position corresponding to the grating 1011, or the fiber cell 103 can be wrapped around the surface of the grating region.

[0047] More specifically, the fiber cell 103 can circumferentially cover the grid region; that is, the fiber cell 103 can cover the grid region with the corresponding optical fiber segment as the axis. For example... Figure 1and Figure 2 As shown ( Figure 2 for Figure 1 (Left view of fiber cell 103) The fiber cell 103 can be a hollow cylindrical structure, through which optical fiber 101 passes, so that the fiber cell 103 can circumferentially cover the grid region.

[0048] Accordingly, the negative electrode conductive layer 1031, the negative electrode material layer 1032, the electrolyte layer 1033, the positive electrode material layer 1034, and the positive electrode conductive layer 1035 are sequentially stacked on the grating 1011 from the inside out. Specifically, the negative electrode conductive layer 1031, the negative electrode material layer 1032, the electrolyte layer 1033, the positive electrode material layer 1034, and the positive electrode conductive layer 1035 are stacked sequentially along the surface of the optical fiber 101 and away from the optical fiber 101. That is, the negative electrode conductive layer 1031 covers the surface of the grating region, the negative electrode material layer 1032 covers the surface of the negative electrode conductive layer 1031, the electrolyte layer 1033 covers the surface of the negative electrode material layer 1032, the positive electrode material layer 1034 covers the surface of the electrolyte layer 1033, and the positive electrode conductive layer 1035 covers the surface of the positive electrode material layer 1034. More specifically, the coatings of the negative electrode conductive layer 1031, the negative electrode material layer 1032, the electrolyte layer 1033, the positive electrode material layer 1034, and the positive electrode conductive layer 1035 can all be circumferential coatings.

[0049] In the fiber battery 103, the negative electrode conductive layer 1031 can be used to connect to the negative electrode of the target device, and the positive electrode conductive layer 1035 can be used to connect to the positive electrode of the target device. Thus, the fiber battery 103 is connected in parallel with the target device, enabling the voltage detection device 100 to detect the voltage of the target device. The target device can be any device requiring voltage detection, such as a single cell in a lithium-ion battery pack.

[0050] In this embodiment, the voltage detection device 100 performs voltage detection on the following principle:

[0051] When using the voltage detection device 100, the fiber battery 103 is connected in parallel with the target device to ensure that their voltages are identical. During the synchronization of the voltage of the fiber battery 103 with the voltage of the target device, lithium ions in the fiber battery 103 continuously insert or extract between the positive and negative electrodes, causing the volume of the fiber battery 103 to expand or contract. For example, during the charging process of a single cell, the voltage of the fiber battery 103 continuously increases, and lithium ions in the fiber battery 103 continuously extract from the positive electrode material layer 1034, pass through the electrolyte layer 1033, and insert into the negative electrode material layer 1032. This causes the volume of the fiber battery 103 to expand, especially the negative electrode material layer 1032. Conversely, during the discharging process of a single cell, the voltage of the fiber battery 103 continuously decreases, and lithium ions in the fiber battery 103 continuously extract from the negative electrode material layer 1032, pass through the electrolyte layer 1033, and insert into the positive electrode material layer 1034. This causes the volume of the fiber battery 103 to contract, especially the negative electrode material layer 1032. That is, during the process of voltage synchronization between the fiber battery 103 and the target device to detect the voltage of the target device, the volume of the fiber battery 103 will change. The change in the volume of the fiber battery 103 will cause deformation of the grating region, and the deformation of the grating region will further cause a change in the reflection wavelength of the grating 1011.

[0052] In short, the voltage of the fiber battery 103 is related to the amount of lithium intercalated in its negative electrode material layer 1032. The deformation of the negative electrode material layer 1032 due to lithium intercalation or deintercalation, as well as the stress on the grid region, can be reflected by the wavelength change of the grating 1011. Therefore, based on the above logic, the voltage of the fiber battery 103, i.e., the voltage of the target device, can be obtained by monitoring the wavelength change of the grating 1011.

[0053] In the embodiments of this application, the combined structure of the fiber battery 103 and the grating 1011 can also be regarded as a fiber battery sensing unit.

[0054] In order to enable the volume change of the fiber battery 103 to cause deformation of the grid region, and in order to improve the accuracy and sensitivity of voltage detection, the fiber battery 103 can be tightly attached to the surface of the grid region. Specifically, the negative electrode conductive layer 1031 is tightly attached to the surface of the grid region, and the negative electrode material layer 1032, the electrolyte layer 1033, the positive electrode material layer 1034, and the positive electrode conductive layer 1035 are sequentially and tightly stacked.

[0055] It is understood that the voltage detection device 100 provided in this application includes an optical fiber 101 with a grating 1011, a wavelength detection device 102, and a fiber battery 103. The fiber battery 103 includes a negative electrode conductive layer 1031, a negative electrode material layer 1032, an electrolyte layer 1033, a positive electrode material layer 1034, and a positive electrode conductive layer 1035. The fiber battery 103 is disposed at a position corresponding to the grating 1011, and the negative electrode conductive layer 1031, the negative electrode material layer 1032, the electrolyte layer 1033, the positive electrode material layer 1034, and the positive electrode conductive layer 1035 sequentially cover the grating 1011. The wavelength detection device 102 is connected to one end of the optical fiber 101 and is used to detect the reflected wavelength of the grating 1011. Since the voltage detection device 100 provided in this application embodiment can detect the voltage of individual cells in a lithium-ion battery pack, it can solve the problem of the lack of devices in the prior art that can be applied to lithium-ion battery packs to detect the voltage of individual cells.

[0056] In the above embodiments, the process of forming the fiber battery 103 on the grating 1011, or the fabrication process of the fiber battery sensing unit, can be as follows:

[0057] The negative electrode conductive layer 1031 can be a copper layer. During fabrication, a copper layer can be uniformly coated on the surface of the gate region using methods such as magnetron sputtering or vapor deposition.

[0058] After the copper layer is formed, the first slurry can be uniformly coated onto the surface of the copper layer using methods such as dip coating or 3D printing to form the negative electrode material layer 1032. The first slurry can be obtained by mixing the negative electrode material, the first conductive agent, and the first binder in a preset ratio; the negative electrode material can include graphite, silicon carbide, etc., and the first conductive agent can be conductive carbon black. The preset ratio can be set according to actual needs.

[0059] After the negative electrode material layer 1032 is formed, a second slurry can be uniformly coated on the surface of the negative electrode material layer 1032 using methods such as dip coating or 3D printing to form the electrolyte layer 1033. The second slurry may include any one or more of polyethylene oxide, polyvinylidene fluoride, etc.

[0060] After the electrolyte layer 1033 is formed, a third slurry can be uniformly coated onto the surface of the electrolyte layer 1033 using methods such as dip coating or 3D printing to form the positive electrode material layer 1034. The third slurry can be obtained by mixing the positive electrode material, the second conductive agent, and the second binder in a preset ratio; the positive electrode material can include ternary lithium, lithium iron phosphate, etc., and the second conductive agent can be conductive carbon black. The preset ratio can be set according to actual needs.

[0061] The positive electrode conductive layer 1035 can be an aluminum layer. After the positive electrode material layer 1034 is formed, an aluminum layer can be uniformly coated on the surface of the positive electrode material layer 1034 by magnetron sputtering, vapor deposition or other methods.

[0062] In practical applications, in order to enable the fiber battery 103 to charge and discharge normally and avoid short circuits, and to enable the fiber battery 101 to be connected to target devices, in one embodiment, the negative electrode conductive layer 1031 completely covers the grating 1011, one end of the negative electrode conductive layer 1031 exposes the negative electrode material layer 1032, the electrolyte layer 1033 completely covers the negative electrode material layer 1032, the positive electrode material layer 1034 covers at least a portion of the electrolyte layer 1033, and the positive electrode conductive layer 1035 completely covers the positive electrode material layer 1034.

[0063] like Figure 1 As shown, the left end of the negative electrode conductive layer 1031 is exposed and can be used as the negative electrode of an external target device. The other unexposed portions of the negative electrode conductive layer 1031 are covered by either the negative electrode material layer 1032 or the electrolyte layer 1033. The surface of the negative electrode material layer 1032 furthest from the negative electrode conductive layer 1031 is completely covered by the electrolyte layer 1033. A portion of the surface of the electrolyte layer 1033 furthest from the negative electrode material layer 1032 is covered by the positive electrode material layer 1034; the positive electrode material layer 1034 faces the electrolyte layer 1033. The surface of the positive electrode material layer 1034 furthest from the electrolyte layer 1033 is completely covered by the positive electrode conductive layer 1035.

[0064] Furthermore, along the extension direction of optical fiber 101, the length of the negative electrode conductive layer 1031 can be 2.5-3.5 cm, specifically 3 cm. The thickness of the negative electrode conductive layer 1031 can be 400-600 nm, specifically 500 nm. Along the extension direction of optical fiber 101, the length of the negative electrode material layer 1032 can be 1-2 cm, specifically 1.5 cm. The thickness of the negative electrode material layer 1032 can be 1-10 μm. One end of the negative electrode conductive layer 1031 is exposed for 0.5-1.5 cm, specifically 1 cm, for subsequent connection of the wire to the negative electrode of the target device. The thickness of the electrolyte layer 1033 can be 1-10 μm. Along the extension direction of optical fiber 101, the length of the positive electrode material layer 1034 can be 0.5-1.5 cm, specifically 1 cm. The thickness of the positive electrode material layer 1034 can be 1-10 μm. The thickness of the positive conductive layer 1035 can be 400-600nm, for example, it can be 500nm.

[0065] In order to further accurately measure the voltage of the target device, in one embodiment, the grating 1011 is a Bragg grating.

[0066] Bragg gratings are sensitive to stress changes. They exhibit a spatial phase periodic distribution on fiber 101, forming a narrow-band filter or mirror that can reflect light of a specific wavelength (called the Bragg wavelength).

[0067] The formula for calculating the Bragg wavelength is as follows:

[0068] λ B =2n neff Λ

[0069] Where, λ B n is the Bragg wavelength. neff Let n be the effective refractive index and Λ be the grating period. When a fiber grating deforms, it causes a change in the grating period Λ, and the change in the overall stress state inside the fiber also affects the effective refractive index n. neff The light λ changes, thereby satisfying the reflection wavelength condition. B This will also change. Wavelength offset Δλ B It can be read by the wavelength detection device 102.

[0070] When a fiber grating deforms, the characteristic wavelength shift Δλ caused by the stress change B It can be described by the following formula:

[0071] Δλ B =K ε ε

[0072] Among them, K ε ε represents the strain coefficient of the optical fiber, and ε represents the strain value that occurs in the optical fiber.

[0073] Therefore, based on the above formula, the wavelength offset Δλ detected by the wavelength detection device 102 can be used to calculate the wavelength offset. B This is used to determine the strain occurring in the optical fiber, and thus the degree of deformation.

[0074] The degree of deformation of the optical fiber is related to the volume change of the fiber cell 103. For example, the state when the fiber cell 103 is not deformed is called the initial state of the fiber cell 103, and the state when the optical fiber 101 is not deformed is called the initial state of the optical fiber 101. Assuming the fiber cell 103 is in its initial state, the optical fiber 101 is also in its initial state. Therefore, when the fiber cell 103 expands in volume while charging, the optical fiber 101 is compressed (specifically, the grid region on the optical fiber 101 is compressed). The greater the expansion of the fiber cell 103, the greater the compression of the optical fiber 101. Correspondingly, when the fiber cell 103 discharges and its volume returns from the expanded state to its initial state, the optical fiber 101 also returns to its initial state.

[0075] Furthermore, the volume change of the fiber battery 103 is related to the amount of lithium ions embedded in the negative electrode material, that is, to the state of charge and voltage of the battery.

[0076] Therefore, the wavelength shift Δλ of the grating can be used to... B The voltage of the fiber battery 103 is obtained.

[0077] That is, different voltages correspond to different amounts of lithium intercalation in the negative electrode material layer 1032, and the volume change caused by lithium ion intercalation directly affects the grating 1011. When the grating 1011 senses the volume change of the fiber battery 103, it causes a change in the grating period Λ, thereby shifting the reflected wavelength relative to the initial reflected wavelength. By detecting the reflected wavelength, the strain value at the position of the grating 1011 can be determined, and by conversion, the voltage of the fiber battery corresponding to the grating can be obtained, thus obtaining the voltage of the target device connected in parallel with the fiber battery.

[0078] When the fiber cell is a graphite-ternary system cell, tests show that the wavelength change of the grating, the volume change of the fiber cell, and their correspondence with the state of charge can be as follows: Figure 3 As shown.

[0079] In order to simultaneously detect the voltage of multiple target devices, such as multiple individual cells in a lithium-ion battery pack, in one embodiment, the optical fiber 101 has multiple gratings 1011, and the voltage detection device 100 includes multiple fiber cells 103; the multiple fiber cells 103 are respectively disposed at positions corresponding to each grating 1011.

[0080] That is, one fiber cell 103 corresponds to one grating 1011. The arrangement of each fiber cell 103 and the way it is formed on its corresponding grating 1011 can be referred to the foregoing content, and will not be repeated here.

[0081] Taking the detection object as multiple individual cells in a lithium-ion battery pack as an example, when using the voltage detection device 100, optical fibers 101 with fiber batteries 103 can be laid on each individual cell, and each fiber battery 103 is connected to each individual cell A in a one-to-one correspondence. Specifically, for any pair of fiber batteries 103 and individual cells A, the negative electrode conductive layer 1031 of the fiber battery 103 is connected to the negative electrode of the individual cell A, and the positive electrode conductive layer 1035 of the fiber battery is connected to the positive electrode of the individual cell A, such as... Figure 4 As shown.

[0082] It is understandable that by adopting the above scheme, by setting the optical fiber 101 to have multiple gratings 1011 and the voltage detection device 100 to include multiple fiber cells 103, the voltage of hundreds or even thousands of individual cells can be detected based on only one optical fiber, which can greatly reduce the cost, wiring difficulty, and space required of the voltage detection device.

[0083] Considering that when performing voltage detection on multiple target devices, the wavelength detection device 102 will obtain multiple reflected wavelengths at the same time, and thus multiple voltages can be calculated. In order to ensure that each voltage corresponds accurately to each target device, in one embodiment, any two gratings among the plurality of gratings 1011 have different initial reflected wavelengths, wherein the initial reflected wavelength is the reflected wavelength corresponding to the grating when it has not undergone deformation.

[0084] Therefore, each grating can be distinguished, allowing the detected voltages to accurately correspond to each target device. This also enables independent detection of each grating.

[0085] Based on the voltage detection device provided in the above embodiments of this application, this application also provides a voltage detection method, which can use the voltage detection device provided in the above embodiments of this application to detect the voltage of a target device, such as... Figure 5 As shown, the detection method may include the following steps:

[0086] Step 201: Control the connection of the negative conductive layer in the fiber battery to the negative electrode of the target device, and control the connection of the positive conductive layer in the fiber battery to the positive electrode of the target device.

[0087] In this embodiment of the application, the above connection can be achieved using wires.

[0088] When there are multiple fiber batteries and multiple target devices, the fiber batteries are connected to the target devices in a one-to-one correspondence.

[0089] Step 202: Obtain the reflection wavelength of the grating corresponding to the fiber battery.

[0090] In this embodiment of the application, the reflected wavelength can be obtained by wavelength detection device 102.

[0091] When there are multiple fiber batteries and multiple target devices, the acquired reflection wavelengths can also be multiple.

[0092] Step 203: Determine the voltage of the target device based on the reflected wavelength.

[0093] Specifically, determining the voltage of the target device based on the reflected wavelength may include:

[0094] Based on the reflected wavelength, the degree of deformation occurring in the region on the optical fiber corresponding to the grating is determined, and the voltage of the target device is determined based on the degree of deformation.

[0095] The degree of deformation can be reflected by the strain value. The specific process for determining the voltage of the target equipment can be found in the foregoing content and will not be repeated here.

[0096] It is understood that the voltage detection method provided in this application embodiment can utilize the voltage detection device 100 provided in the above embodiment. The voltage detection device 100 includes an optical fiber 101 with a grating 1011, a wavelength detection device 102, and a fiber battery 103. The fiber battery 103 includes a negative electrode conductive layer 1031, a negative electrode material layer 1032, an electrolyte layer 1033, a positive electrode material layer 1034, and a positive electrode conductive layer 1035. The fiber battery 103 is disposed at a position corresponding to the grating 1011. The negative electrode conductive layer 1031, the negative electrode material layer 1032, the electrolyte layer 1033, the positive electrode material layer 1034, and the positive electrode conductive layer 1035 sequentially cover the grating 1011. The wavelength detection device 102 is connected to one end of the optical fiber 101 and is used to detect the reflected wavelength of the grating 1011. Therefore, the voltage of individual cells in a lithium-ion battery pack can be detected, thereby solving the problem of the lack of existing devices that can be applied to lithium-ion battery packs to detect the voltage of individual cells.

[0097] Based on the voltage detection device provided in the above embodiments of this application, this application also provides a battery system 300, such as... Figure 4 As shown, the battery system 300 includes a lithium-ion battery pack and a voltage detection device 100 as described in the above embodiment; the lithium-ion battery pack includes multiple individual cells A, and the voltage detection device 300 includes multiple fiber cells 103; wherein each individual cell A is connected to each fiber cell in a one-to-one correspondence, the positive electrode of the individual cell A is connected to the positive electrode conductive layer of the fiber cell 103, and the negative electrode of the individual cell A is connected to the negative electrode conductive layer of the fiber cell 103.

[0098] In practical applications, the battery system 300 can be used as a whole, for example, as a whole in a vehicle.

[0099] It is understood that the battery system 300 provided in this application includes the voltage detection device 100 provided in the above embodiment. The voltage detection device 100 includes an optical fiber 101 with a grating 1011, a wavelength detection device 102, and a fiber battery 103. The fiber battery 103 includes a negative electrode conductive layer 1031, a negative electrode material layer 1032, an electrolyte layer 1033, a positive electrode material layer 1034, and a positive electrode conductive layer 1035. The fiber battery 103 is disposed at a position corresponding to the grating 1011. The negative electrode conductive layer 1031, the negative electrode material layer 1032, the electrolyte layer 1033, the positive electrode material layer 1034, and the positive electrode conductive layer 1035 sequentially cover the grating 1011. The wavelength detection device 102 is connected to one end of the optical fiber 101 and is used to detect the reflected wavelength of the grating 1011. Therefore, the voltage of individual cells in a lithium-ion battery pack can be detected, thereby solving the problem of the lack of existing devices that can be applied to lithium-ion battery packs to detect the voltage of individual cells.

[0100] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0101] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A voltage detection device, characterized in that, The voltage detection device includes an optical fiber with a grating, a wavelength detection device, and a fiber battery; The fiber battery includes a negative electrode conductive layer, a negative electrode material layer, an electrolyte layer, a positive electrode material layer, and a positive electrode conductive layer. The fiber battery is positioned at the location corresponding to the grating; The negative electrode conductive layer, the negative electrode material layer, the electrolyte layer, the positive electrode material layer, and the positive electrode conductive layer sequentially cover the grating from the inside out; The wavelength detection device is connected to one end of the optical fiber and is used to detect the reflected wavelength of the grating; The voltage detection device is used to detect the voltage of the target device. The negative conductive layer in the fiber battery is used to connect to the negative electrode of the target device, and the positive conductive layer in the fiber battery is used to connect to the positive electrode of the target device.

2. The voltage detection device according to claim 1, characterized in that, The grating is a Bragg grating.

3. The voltage detection device according to claim 1, characterized in that, The optical fiber has multiple gratings, and the voltage detection device includes multiple fiber cells; The multiple fiber batteries are respectively positioned at the corresponding positions of each grating.

4. The voltage detection device according to claim 3, characterized in that, Among the plurality of gratings, any two gratings have different initial reflection wavelengths, wherein the initial reflection wavelength is the reflection wavelength corresponding to the grating when it has not undergone deformation.

5. The voltage detection device according to claim 1, characterized in that, In the fiber battery, the negative electrode conductive layer, the negative electrode material layer, the electrolyte layer, the positive electrode material layer, and the positive electrode conductive layer are sequentially stacked. The negative electrode conductive layer completely covers the grating, one end of the negative electrode conductive layer exposes the negative electrode material layer, the electrolyte layer completely covers the negative electrode material layer, the positive electrode material layer covers at least a portion of the electrolyte layer, and the positive electrode conductive layer completely covers the positive electrode material layer.

6. The voltage detection device according to claim 1, characterized in that, The negative electrode conductive layer is a copper layer, and the positive electrode conductive layer is an aluminum layer.

7. The voltage detection device according to claim 1, characterized in that, The negative electrode material layer is obtained by coating the surface of the negative electrode conductive layer with a first slurry, wherein the first slurry includes a negative electrode material, a first conductive agent, and a first binder. The electrolyte layer is obtained by coating the surface of the negative electrode material layer with a second slurry, the second slurry comprising polyethylene oxide and / or polyvinylidene fluoride; The positive electrode material layer is obtained by coating the surface of the electrolyte layer with a third slurry, the third slurry comprising a positive electrode material, a second conductive agent, and a second binder.

8. A voltage detection method, characterized in that, The detection method is used to detect the voltage of a target device using the voltage detection device according to any one of claims 1-7, and the detection method includes: The negative electrode conductive layer in the fiber battery is connected to the negative electrode of the target device, and the positive electrode conductive layer in the fiber battery is connected to the positive electrode of the target device. Obtain the reflection wavelength of the grating corresponding to the fiber cell; The voltage of the target device is determined based on the reflected wavelength.

9. The voltage detection method according to claim 8, characterized in that, Determining the voltage of the target device based on the reflected wavelength includes: Based on the reflected wavelength, the degree of deformation occurring in the region on the optical fiber corresponding to the grating is determined, and the voltage of the target device is determined based on the degree of deformation.

10. A battery system, characterized in that, The system includes a lithium-ion battery pack and a voltage detection device according to any one of claims 1-7; The lithium-ion battery pack includes multiple individual cells, and the voltage detection device includes multiple fiber cells. Each individual cell is connected to each fiber cell in a one-to-one correspondence. The positive electrode of the individual cell is connected to the positive conductive layer of the fiber cell, and the negative electrode of the individual cell is connected to the negative conductive layer of the fiber cell.

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