Battery monomer, battery and electric device

Abstract

The embodiment of the invention provides a battery monomer, a battery and an electric device. The battery monomer comprises a shell, and an electrolyte and an optical fiber evanescent wave sensor which are accommodated in the shell. Wherein the optical fiber evanescent wave sensor is partially arranged in the electrolyte and is used for transmitting part of energy of incident infrared laser to the electrolyte in an evanescent wave form and then outputting emergent infrared laser. According to the technical scheme provided by the embodiment of the invention, the state change of the electrolyte in the charge-discharge cycle process can be dynamically monitored, and the decomposition mechanism and the dynamic change of the electrolyte can be accurately analyzed, so that the performance of the battery monomer can be improved.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of battery technology, and in particular, to a battery cell, a battery, and an electrical device. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automotive industry. In this case, electric vehicles have become an important part of the sustainable development of automotive products due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] During the charge and discharge cycle of a battery cell, the electrolyte is constantly consumed and decomposed, causing the electrolyte state to change. For example, the structure and content of each component in the electrolyte will change, thus affecting the battery performance, such as the battery's energy density, cycle life, safety performance, etc. Therefore, dynamically monitoring the state changes of the electrolyte during the charge and discharge process is crucial to improving the performance of the battery cell. However, at present, there is no device that can dynamically monitor the state changes of the electrolyte during the charge and discharge process. Summary of the invention

[0004] The embodiments of the present application provide a battery cell, a battery and an electrical device, which can dynamically monitor the state changes of the electrolyte during the charge and discharge cycle, help to more accurately analyze the decomposition mechanism and kinetic changes of the electrolyte, and thus help improve the performance of the battery cell.

[0005] In a first aspect, a battery cell is provided, comprising a housing, an electrolyte and an optical fiber evanescent wave sensor; the electrolyte is contained in the housing, and part of the optical fiber evanescent wave sensor is arranged in the electrolyte; the optical fiber evanescent wave sensor is used to receive incident infrared laser, and after transmitting part of the energy of the incident infrared laser to the electrolyte in the form of evanescent waves, output an outgoing infrared laser.

[0006] In the embodiment of the present application, by partially arranging the fiber optic evanescent wave sensor in the electrolyte, the fiber optic evanescent wave sensor can transmit part of the energy of the received incident infrared laser to the electrolyte in the form of an evanescent wave, and then output the incident infrared laser of the remaining energy, that is, output the outgoing infrared laser. By analyzing and processing the outgoing infrared laser and the incident infrared laser, the information of the infrared absorption spectrum of the evanescent wave absorbed by each component in the electrolyte can be obtained. In this way, the decomposition products of the electrolyte can be identified, and the molecular structure and content changes of each component in the electrolyte can be obtained, so that the state of the electrolyte during the charge and discharge cycle can be dynamically and continuously monitored. This is conducive to quantitatively characterizing the residual amount of each component in the electrolyte after the charge and discharge cycle, and to more accurately analyze the decomposition mechanism and kinetic changes of the electrolyte, so as to facilitate timely maintenance of the battery cell when the performance of the battery cell is abnormal, so as to improve the performance of the battery cell. In addition, during the monitoring process, the structure of the battery cell remains relatively intact, and the impact on the further charge and discharge cycle of the battery cell is small.

[0007] In a possible implementation, the optical fiber evanescent wave sensor includes a core and a cladding, the core includes an input transmission segment, a sensing segment and an output transmission segment connected in sequence, and the cladding is coated on the outer peripheral surface of the input transmission segment and the output transmission segment; the sensing segment is arranged in the electrolyte, and the sensing segment is used to transmit part of the energy of the incident infrared laser to the electrolyte in the form of the evanescent wave, and then output the outgoing infrared laser.

[0008] In the embodiment of the present application, the core portion of the optical fiber evanescent wave sensor that is not covered with a cladding, that is, the sensing segment of the core is arranged in the electrolyte of the battery cell, so that the core can directly contact the electrolyte without passing through the cladding. In this way, when the incident infrared laser is transmitted to the sensing segment of the core, the evanescent wave generated by the incident infrared laser can be transmitted to the electrolyte at the interface between the sensing segment and the electrolyte and absorbed by the electrolyte, thereby analyzing and processing the outgoing infrared laser and the incident infrared laser output by the optical fiber evanescent wave sensor, it is possible to obtain information on the infrared absorption spectrum of the evanescent wave absorbed by each component in the electrolyte.

[0009] In one possible implementation, at least part of the input transmission segment and the output transmission segment are arranged outside the housing; the input transmission segment is used to receive the incident infrared laser and transmit the incident infrared laser to the sensing segment; the output transmission segment is used to output the outgoing infrared laser transmitted by the sensing segment.

[0010] In an embodiment of the present application, by arranging at least part of the input transmission segment and the output transmission segment of the fiber core outside the outer shell, the optical fiber evanescent wave sensor can be connected to other devices other than the battery cell through the input transmission segment and the output transmission segment. For example, the optical fiber evanescent wave sensor can be connected to the laser through the part of the input transmission segment located outside the outer shell to receive the incident infrared laser output by the laser. The optical fiber evanescent wave sensor can also be connected to the detection component through the part of the output transmission segment located outside the outer shell to facilitate the detection component to analyze and process the outgoing infrared laser.

[0011] In a possible implementation, the input transmission section includes a first transmission section and a first transition section, and two ends of the first transition section are respectively connected to the first transmission section and the sensing section; the output transmission section includes a second transmission section and a second transition section, and two ends of the second transition section are respectively connected to the second transmission section and the sensing section; wherein, along the direction from the first transmission section to the sensing section, the diameter d1 of the first transition section changes from large to small; and along the direction from the second transmission section to the sensing section, the diameter d2 of the second transition section changes from large to small.

[0012] In the embodiment of the present application, the transition part where the input transmission segment and the output transmission segment of the fiber core are connected to the sensing segment is set in a conical shape, that is, the closer the input transmission segment and the output transmission segment are to the sensing segment, the thinner they are, so that the diameter d3 of the sensing segment connected between the input transmission segment and the output transmission segment is smaller. When the sensing segment is set in the electrolyte of the battery cell, the smaller diameter size can reduce the influence of the sensing segment on the battery interface, which is conducive to reducing the influence of the sensing segment in the electrolyte on the performance of the battery cell.

[0013] In a possible implementation, the diameter d3 of the sensing segment is 50 μm to 250 μm; optionally, the diameter d3 of the sensing segment is 70 μm to 150 μm.

[0014] In the embodiment of the present application, by reasonably setting the diameter size of the sensing segment of the fiber core, on the one hand, it is possible to avoid the sensing segment from breaking due to being too thin, which is beneficial to ensuring the quality reliability of the sensing segment and facilitating the processing and production of the optical fiber evanescent wave sensor; on the other hand, it is possible to reduce the impact of the sensing segment on the battery interface, which is beneficial to reducing the impact of the sensing segment in the electrolyte on the performance of the battery cell.

[0015] In a possible implementation, the fiber core includes any one of a sulfur-containing compound, a selenium-containing compound, a tellurium-containing compound, and a silicon-containing compound.

[0016] It should be understood that the optical fiber evanescent wave sensor can adopt chalcogenide optical fiber or silica-based optical fiber. Among them, in the chalcogenide optical fiber, the core can include a compound containing chalcogen elements (sulfur, selenium, tellurium); in the silica-based optical fiber, the core can include a compound containing silicon, for example, the core can include silicon dioxide. In the embodiment of the present application, the optical fiber evanescent wave sensor adopts chalcogenide optical fiber or silica-based optical fiber, which can have good resistance to electrolyte corrosion. This is conducive to avoiding the optical fiber evanescent wave sensor from being corroded by electrolyte, and further conducive to ensuring the reliability of the optical fiber evanescent wave sensor.

[0017] In a second aspect, a battery is provided, comprising the battery cell according to the first aspect or any implementation manner of the first aspect.

[0018] In a possible implementation, the battery further includes a laser, and the laser is connected to the optical fiber evanescent wave sensor of the battery cell; the laser is used to output incident infrared laser to the optical fiber evanescent wave sensor.

[0019] In a possible implementation, the battery further includes a detection component, which is connected to the optical fiber evanescent wave sensor of the battery cell; the detection component is used to receive the outgoing infrared laser output by the optical fiber evanescent wave sensor.

[0020] In a possible implementation, the detection component includes an infrared detector, an infrared spectrometer and a computer connected in sequence, and the infrared detector is connected to the optical fiber evanescent wave sensor; the infrared detector is used to receive the outgoing infrared laser output by the optical fiber evanescent wave sensor, and generate an electrical signal based on the outgoing infrared laser and then output it to the infrared spectrometer; the infrared spectrometer and the computer are used to obtain information on the infrared absorption spectrum of the electrolyte of the battery cell based on the electrical signal.

[0021] In a possible implementation, the number of the battery cells in the battery may be multiple, wherein the optical fiber evanescent wave sensor of each of the battery cells is connected to the laser and the detection component.

[0022] In a third aspect, an electrical device is provided, comprising the battery according to the second aspect or any implementation of the second aspect.

[0023] Among them, for the beneficial effects of the second to third aspects, please refer to the beneficial effects of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0025] Figure 1 It is a structural schematic diagram of a vehicle provided in one embodiment of the present application.

[0026] Figure 2 It is a schematic diagram of the structure of a battery provided in one embodiment of the present application.

[0027] Figure 3 It is a schematic diagram of the product form of a battery cell provided in one embodiment of the present application.

[0028] Figure 4 A method provided in an embodiment of the present application Figure 3 Schematic diagram of the exploded structure of a battery cell is shown.

[0029] Figure 5 Another embodiment of the present application provides Figure 3 Schematic diagram of the exploded structure of a battery cell is shown.

[0030] Figure 6 It is a schematic diagram of the structure of a battery provided in one embodiment of the present application.

[0031] Figure 7 It is a flow chart of a method for monitoring an electrolyte provided in one embodiment of the present application.

[0032] Explanation of reference numerals: 1-electric device; 10-battery; 20-battery cell; 30-controller; 40-motor; 111-first part of the housing; 112-second part of the housing; 112a-bottom plate; 112b-side plate; 21-housing; 22-electrode assembly; 23-optical fiber evanescent wave sensor; 24-connecting member; 211-housing; 212-cover plate; 213-electrode terminal; 213a-positive electrode terminal; 213b-negative electrode terminal; 221-positive electrode plate; 221 a-positive electrode ear; 222-negative electrode piece; 222a-negative electrode ear; 223-isolation membrane; 231-fiber core; 2311-input transmission section; 2311a-first transmission section; 2311b-first transition section; 2312-sensing section; 2313-output transmission section; 2313a-second transmission section; 2313b-second transition section; 232-cladding; 120-laser; 130-detection component; 131-infrared detector; 132-infrared spectrometer; 133-computer.

[0033] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] Unless otherwise defined, all technical and scientific terms used in the embodiments of the present application have the same meanings as those generally understood by technicians in the technical field of the embodiments of the present application; the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" in the specification and claims of the present application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0036] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0037] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0038] In the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the embodiments of the present application, the character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0039] In the automotive industry environment that uses traditional energy as power supply, environmental pollution problems are becoming more and more serious. Actively developing new energy vehicles can reduce harm to the environment. For new energy vehicles, battery technology is an important factor related to its development.

[0040] A battery generally refers to a physical module that includes one or more battery cells to provide electrical energy. For example, the battery mentioned in this application may include a battery module or a battery pack. A battery generally includes a box for encapsulating one or more battery cells. The box can reduce the impact of liquid or other foreign matter on the charging or discharging of the battery cells.

[0041] Optionally, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, a lead acid battery or an air battery, etc., which is not limited in the present embodiment. In some embodiments, the battery cell may also be referred to as a battery cell.

[0042] A battery cell may include an electrode assembly and an electrolyte. The electrode assembly may be composed of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet may include a positive current collector and a positive active material layer, the positive active material layer is coated on the surface of the positive current collector, the current collector not coated with the positive active material layer protrudes from the current collector coated with the positive active material layer, and the current collector not coated with the positive active material layer serves as a positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive current collector may be aluminum, and the positive active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet may include a negative current collector and a negative active material layer, the negative active material layer is coated on the surface of the negative current collector, the current collector not coated with the negative active material layer protrudes from the current collector coated with the negative active material layer, and the current collector not coated with the negative active material layer serves as a negative electrode tab. The material of the negative current collector may be copper, and the negative active material may be carbon or silicon, etc. In order to ensure that a large current can pass without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the isolation film can be polypropylene (PP) or polyethylene (PE). In addition, the electrode assembly can be a winding structure or a laminated structure, and the embodiments of the present application are not limited thereto.

[0043] The electrolyte is the carrier of ion transmission in the battery, and plays the role of conducting ions between the positive and negative electrodes. The electrolyte can be liquid or fixed. The electrolyte is generally composed of electrolyte lithium salt, organic solvent, and additives in proportion. Taking into account comprehensive factors such as battery cost and safety performance, the commonly used electrolyte lithium salt is lithium hexafluorophosphate (LiPF6). LiPF6 has high electrochemical reliability, room temperature working requirements, and price advantages brought by industrial scale effects. In addition, electrolyte lithium salts such as lithium bis(fluorosulfonyl)imide (LiFSI) and lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) have also begun to be used in the configuration of electrolytes, so as to achieve the purpose of increasing battery energy density. Compared with LiPF6, LiFSI has better performance in thermal stability, conductivity, cycle life, low temperature performance, etc.

[0044] At present, during the charge and discharge cycle of a battery cell, the electrolyte is usually continuously consumed and decomposed. For example, the electrolyte will be consumed and decomposed by the surface reaction of the positive electrode or the negative electrode, or other side reactions, resulting in changes in the state of the electrolyte, such as changes in the molecular structure and content of each component in the electrolyte. When the above changes are abnormal, the performance of the battery may be abnormal. For example, the consumption and decomposition of some electrolytes during the charge and discharge cycle are accompanied by the generation of gases such as CO, CO2, and hydrocarbons. When the gas generated is excessive, it is easy to cause a series of safety problems, resulting in a decrease in the energy density, cycle life, and safety performance of the battery. Therefore, dynamic monitoring of the state changes of the electrolyte during the charge and discharge cycle is helpful to carry out timely maintenance of the battery when the battery performance is abnormal, which is beneficial to improve the performance of the battery cell.

[0045] However, at present, there is no device that can dynamically monitor the state changes of the electrolyte during the charge and discharge cycle.

[0046] Based on the above content, an embodiment of the present application provides a battery cell. In the battery cell, by arranging part of the optical fiber evanescent wave sensor in the electrolyte, the optical fiber evanescent wave sensor can transmit part of the energy of the received incident infrared laser to the electrolyte in the form of an evanescent wave, and then output the incident infrared laser of the remaining energy, that is, output an outgoing infrared laser. By analyzing and processing the outgoing infrared laser and the incident infrared laser, the information of the infrared absorption spectrum of the evanescent wave of each component in the electrolyte can be obtained. In this way, the decomposition products of the electrolyte can be identified, and the molecular structure and content changes of each component in the electrolyte can be obtained, so that the state of the electrolyte during the charge and discharge cycle can be dynamically and continuously monitored. This is conducive to quantitatively characterizing the residual amount of each component in the electrolyte after the charge and discharge cycle, and to more accurately analyze the decomposition mechanism and kinetic changes of the electrolyte, so as to facilitate timely maintenance of the battery cell when the performance of the battery cell is abnormal, thereby facilitating the improvement of the performance of the battery cell. In addition, during the monitoring process, the structure of the battery cell remains relatively intact, and the impact on the further charge and discharge cycle of the battery cell is relatively small.

[0047] The battery cell provided in the embodiment of the present application is suitable for use in batteries and electrical devices using the batteries.

[0048] [Electrical devices]

[0049] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0050] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0051] Figure 1This is a schematic diagram of the structure of a vehicle 1 provided in one embodiment of the present application, and the vehicle 1 may be a new energy vehicle. A battery 10, a controller 30, and a motor 40 may be provided inside the vehicle 1. The controller 30 may be used to control the battery 10 to power the motor 40. For example, a battery 10 may be provided at the bottom, front, or rear of the vehicle 1. The battery 10 may be used to power the vehicle 1, for example, the battery 10 may be used as an operating power source for the vehicle 1, for the circuit system of the vehicle 1, for example, for the working power requirements during the start-up, navigation, and operation of the vehicle 1. In another embodiment of the present application, the battery 10 may not only be used as an operating power source for the vehicle 1, but may also be used as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0052] [Battery]

[0053] Figure 2 The schematic diagram of the structure of a battery 10 provided in an embodiment of the present application is shown in FIG. The battery 10 may include a plurality of battery cells 20. The battery 10 may also include a housing (or housing), the interior of the housing may be a hollow structure, and the plurality of battery cells 20 may be accommodated in the housing. Figure 2 As shown, the box body may include two parts, which are respectively referred to as the first part 111 and the second part 112, and the first part 111 and the second part 112 are buckled together. The shapes of the first part 111 and the second part 112 may be determined according to the shape of the combination of multiple battery cells 20, and the first part 111 and the second part 112 may both have an opening. For example, the first part 111 and the second part 111 may both be hollow cuboids and each has only one face as an opening face, the opening of the first part 111 and the opening of the second part 112 are arranged opposite to each other, and the first part 111 and the second part 112 are buckled together to form a box body with a closed chamber. Among them, the box body may include a bottom plate 112a, a side plate 112b and a beam. A plurality of battery cells 20 are connected in parallel or in series or in a mixed combination and are placed in a box body formed by the buckling of the first part 111 and the second part 112.

[0054] Optionally, the battery 10 may also include other structures, which are not described one by one here. For example, the battery 10 may also include a busbar, which may be used to achieve electrical connection between multiple battery cells 20, such as parallel connection, series connection, or mixed connection. Specifically, the busbar may be fixed to the electrode terminal of the battery cell 20 by welding. The electrical energy of the multiple battery cells 20 may be further led out through the box body by a conductive mechanism. Optionally, the conductive mechanism may also belong to the busbar.

[0055] The battery 10 includes multiple battery cells 20 that can be connected in parallel, in series, or in hybrid connection. Hybrid connection refers to a mixture of series connection and parallel connection. Optionally, multiple battery cells 20 can be connected in parallel, in series, or in hybrid connection to form a battery module, and multiple battery modules can be connected in parallel, in series, or in hybrid connection to form a battery. That is, multiple battery cells 20 can directly form a battery, or they can first form a battery module, and then the battery module can form a battery.

[0056] According to different power requirements, the number of battery cells 20 can be set to any value. A plurality of battery cells 20 can be connected in parallel, in series or in a mixed manner to achieve a larger capacity or power.

[0057] [Battery Cell]

[0058] Figure 3 A product morphology diagram of a battery cell 20 provided in an embodiment of the present application is shown. Figure 4 This is a method provided by an embodiment of the present application. Figure 3 The exploded structure of the battery cell 20 is shown. Figure 5 Another embodiment of the present application provides Figure 3 The exploded structure of the battery cell 20 is shown.

[0059] Combination Figure 3 and Figure 4 The battery cell 20 may include a housing 21, an electrode assembly 22, an optical fiber evanescent wave sensor 23, and an electrolyte.

[0060] The housing 21 may include a housing 211 and a cover plate 212. The wall of the housing 211 and the cover plate 212 may both be referred to as the wall of the battery cell 20. The housing 211 is determined according to the shape of one or more electrode assemblies 22 after being combined. For example, the housing 211 may be a hollow cuboid or a cube or a cylinder, and one of the faces of the housing 211 may have an opening so that one or more electrode assemblies 22 may be placed in the housing 211. For example, when the housing 211 is a hollow cuboid or a cube, one of the planes of the housing 211 is an open face, that is, the plane does not have a wall body so that the housing 211 communicates with the inside and outside. When the housing 211 may be a hollow cylinder, the end face of the housing 211 is an open face, that is, the end face does not have a wall body so that the housing 211 communicates with the inside and outside. The cover plate 212 covers the opening and is connected to the housing 211 to form a closed cavity in which the electrode assembly 22 is placed. The electrolyte may be contained in the cavity to wet the electrode assembly 22.

[0061] The battery cell 20 may also include two electrode terminals 213, which may be disposed on the cover plate 212. The cover plate 212 is generally in the shape of a flat plate, and the two electrode terminals 213 are fixed on the flat surface of the cover plate 212. The two electrode terminals 213 may be a positive electrode terminal 213a and a negative electrode terminal 213b, respectively. Each electrode terminal 213 is provided with a corresponding connection member 24, or may also be referred to as a current collecting member 24, which is located between the cover plate 212 and the electrode assembly 22, and is used to electrically connect the electrode assembly 22 and the electrode terminal 213.

[0062] Each electrode assembly 22 may have a positive tab 221a and a negative tab 222a. The positive tab 221a of one or more electrode assemblies 22 is connected to the positive terminal 213a through a connecting member 24, and the negative tab 222a of one or more electrode assemblies 22 is connected to the negative terminal 213b through another connecting member 24.

[0063] In the battery cell 20, the electrode assembly 22 can be provided as a single electrode or multiple electrodes according to actual use requirements. Figure 4 As shown, four independent electrode assemblies 22 may be disposed in the battery cell 20 .

[0064] Part of the fiber optic evanescent wave sensor 23 may be disposed in the electrolyte. The fiber optic evanescent wave sensor 23 may be used to receive incident infrared laser light, and transmit part of the energy of the incident infrared laser light to the electrolyte in the form of evanescent waves, and then output outgoing infrared laser light.

[0065] It should be understood that the fiber optic evanescent wave sensor 23 may refer to an optical fiber that can transmit laser light and generate evanescent waves. The principle of the fiber optic evanescent wave sensor 23 may be based on the fiber optic evanescent wave and total internal reflection theory. Specifically, when the incident infrared laser is incident on the fiber optic evanescent wave sensor 23 at a suitable angle, the incident infrared laser light will be transmitted inside the fiber optic evanescent wave sensor 23 in the form of total internal reflection, and part of the light energy of the incident infrared laser light exists in the form of evanescent waves. When the incident infrared laser light is transmitted to the part of the fiber optic evanescent wave sensor 23 located in the electrolyte, the evanescent wave can penetrate into the electrolyte outside the fiber optic evanescent wave sensor 23 and be absorbed by the electrolyte, and the fiber optic evanescent wave sensor 23 outputs the incident infrared laser light (i.e., the outgoing infrared laser light) of the remaining energy that is not absorbed by the electrolyte. Compared with the incident infrared laser light, the energy of the outgoing infrared laser light is attenuated, and the attenuated part is the energy of the evanescent wave absorbed by the electrolyte. Therefore, by analyzing and processing the incident infrared laser and the outgoing infrared laser, the infrared absorption spectrum information of the evanescent wave absorbed by each component in the electrolyte can be obtained. The infrared spectrum absorption information can include the information of the characteristic absorption peaks corresponding to each component in the electrolyte on the infrared absorption spectrum.

[0066] Since different molecular structures have different characteristic absorption peaks in the infrared absorption spectrum, the molecular structure and content of each component in the electrolyte can be obtained based on the information of the characteristic absorption peak. In addition, during the charge and discharge cycle, as the electrolyte is continuously consumed and decomposed, the molecular structure and content of each component in the electrolyte will also change, and the information of the infrared absorption spectrum of the electrolyte will also change accordingly. Therefore, by real-time analysis of the outgoing infrared laser and the incident infrared laser, the changes in the molecular structure and content of each component in the electrolyte can be obtained, thereby realizing continuous dynamic monitoring of the state of the electrolyte.

[0067] It should also be understood that the wavelength of the incident infrared laser can be within the mid-infrared band. Since the mid-infrared band covers the characteristic absorption peaks corresponding to the molecular structures of most organic and inorganic substances, the incident infrared laser in the mid-infrared band is conducive to faster acquisition of information on the characteristic absorption peaks corresponding to the infrared absorption spectrum of each component in the electrolyte.

[0068] In the battery cell 20 provided in the embodiment of the present application, by partially arranging the optical fiber evanescent wave sensor 23 in the electrolyte, the optical fiber evanescent wave sensor 23 can transmit part of the energy of the received incident infrared laser to the electrolyte in the form of an evanescent wave, and then output the incident infrared laser of the remaining energy, that is, output the outgoing infrared laser. By analyzing and processing the outgoing infrared laser and the incident infrared laser, the information of the infrared absorption spectrum of the evanescent wave absorbed by each component in the electrolyte can be obtained. In this way, the decomposition products of the electrolyte can be identified, and the molecular structure and content changes of each component in the electrolyte can be obtained, so that the state of the electrolyte during the charge and discharge cycle can be dynamically and continuously monitored. This is conducive to quantitatively characterizing the residual amount of each component in the electrolyte after the charge and discharge cycle, and to more accurately analyze the decomposition mechanism and kinetic changes of the electrolyte, so as to facilitate timely maintenance of the battery cell 20 when the performance of the battery cell 20 is abnormal, so as to improve the performance of the battery cell 20. In addition, during the monitoring process, the structure of the battery cell 20 remains relatively intact, and the impact on the further charge and discharge cycle of the battery cell 20 is small.

[0069] In some embodiments, the combination Figure 3 and Figure 4, the optical fiber evanescent wave sensor 23 may include a core 231 and a cladding 232. The core 231 may include an input transmission segment 2311, a sensing segment 2312, and an output transmission segment 2313 connected in sequence, and the cladding 232 is coated on the outer circumference of the input transmission segment 2311 and the output transmission segment 2313. That is, the sensing segment 2312 of the core 231 is exposed and is not coated with the cladding 232. The core 231 may be used to transmit laser signals, such as transmitting optical signals of an input infrared laser and an output infrared laser, and the cladding 232 may be used to protect the input transmission segment 2311 and the output transmission segment 2313 of the core 231.

[0070] The sensing section 2312 of the fiber core 231 may be disposed in the electrolyte of the battery cell 20 and used to transmit part of the energy of the incident infrared laser to the electrolyte in the form of an evanescent wave and then output an outgoing infrared laser.

[0071] In the above technical solution, the portion of the core 231 of the optical fiber evanescent wave sensor 23 that is not coated with the cladding 232, that is, the sensing segment 2312 of the core 231, is arranged in the electrolyte of the battery cell 20, so that the core 231 can directly contact the electrolyte without passing through the cladding 232. In this way, when the incident infrared laser is transmitted to the sensing segment 2312 of the core 231, the evanescent wave generated by the incident infrared laser can be transmitted to the electrolyte at the interface between the sensing segment 2312 and the electrolyte and absorbed by the electrolyte, so that by analyzing and processing the outgoing infrared laser and the incident infrared laser output by the optical fiber evanescent wave sensor 23, the information of the infrared absorption spectrum of the evanescent wave absorbed by each component in the electrolyte can be obtained.

[0072] In some embodiments, the combination Figure 3 and Figure 4 , at least part of the input transmission segment 2311 and the output transmission segment 2313 of the core 231 can be arranged outside the shell 21. Among them, the input transmission segment 2311 can be used to receive the incident infrared laser and transmit the incident infrared laser 2311 to the sensing segment 2312, so that the sensing segment 2312 can transmit part of the energy of the incident infrared laser to the electrolyte in the form of an evanescent wave, and then output the outgoing infrared laser. For example, the part of the input transmission segment 2311 located outside the shell 21 can be connected to a laser (not shown in the figure) to receive the incident infrared laser output by the laser. The output transmission segment 2313 can be used to output the outgoing infrared laser transmitted by the sensing segment 2312, so as to analyze and process the outgoing infrared laser. For example, the part of the output transmission segment 2313 located outside the shell 21 can be connected to a detection component (not shown in the figure) to output the outgoing infrared laser to the detection component, so that the detection component can analyze and process the outgoing infrared laser.

[0073] In a possible example, the input transmission section 2311 and the output transmission section 2313 may be completely disposed outside the housing 21. Figure 3 and Figure 4 As shown, the input transmission section 2311 may be located outside the cover plate 212, and the output transmission section 2313 may be located outside the bottom end of the housing 211. The sensing section 2312 may be located in the electrolyte in the housing 211, and both ends of the sensing section 2312 extend to the cover plate 212 and the bottom end of the housing 211, and are connected to the input transmission section 2311 and the output transmission section 2313, respectively.

[0074] In another possible example, parts of the input transmission segment 2311 and the output transmission segment 2313 may be disposed outside the housing 21. Specifically, one end of the input transmission segment 2311 and the output transmission segment 2313 may be disposed in the electrolyte in the housing 211, and respectively connected to the two ends of the sensing segment 2312. The other end of the input transmission segment 2311 may pass through the cover plate 212 and extend to the outside of the housing 21, and the other end of the output transmission segment 2313 may pass through the bottom end of the housing 211 and extend to the outside of the housing 21.

[0075] It should be understood that the above-mentioned embodiment in which at least part of the input transmission section 2311 is located outside the cover plate 212 and at least part of the output transmission section 2313 is located outside the bottom end of the housing 211 is only an example and is not a limitation of the present application. In some other embodiments, at least part of the input transmission section 2311 may also be located outside the bottom end of the housing 211, and at least part of the output transmission section 2313 may be located outside the cover plate 212. Alternatively, at least part of the input transmission section 2311 and at least part of the output transmission section 2313 may both be located outside the cover plate 212.

[0076] For example, in Figure 5 In the illustrated battery cell 20 , a portion of the input transmission section 2311 and a portion of the output transmission section 2313 are both located outside the cover plate 212 .

[0077] Specifically, if Figure 5As shown, the electrode assembly 22 can be a wound structure. Among them, the electrode assembly 22 can include a positive electrode sheet 221, a negative electrode sheet 222, and a separator 223 arranged between the positive electrode sheet 221 and the negative electrode sheet 222. The sensing segment 2312 of the core 231 can be arranged between the negative electrode sheet 222 and the separator 223, and extend along the z direction. One end of the input transmission segment 2311 can be arranged in the electrolyte in the shell 211, and connected to the upper end of the sensing segment 2312 along the z direction. The other end of the input transmission segment 2311 can extend upward along the z direction, passing through the cover plate 212 to the outside of the shell 21. One end of the output transmission segment 2313 can be arranged in the electrolyte of the shell 211, and connected to the lower end of the sensing segment 2312 along the z direction. Part of the output transmission section 2313 can be bent inside the housing 211 , so that the other end of the output transmission section 2313 can also extend upward along the z direction, passing through the cover plate 212 to the outside of the housing 21 .

[0078] It should be understood that the embodiment of the present application does not impose any special restrictions on the specific positions where the input transmission segment 2311 and the output transmission segment 2313 pass through the housing 21, as long as the sensing segment 2312 is located in the electrolyte in the housing 21.

[0079] It should also be understood that during the charge and discharge cycle of the battery cell 20, along with the consumption and decomposition of the electrolyte, a solid electrolyte interphase (SEI) film is easily formed on the surface of the negative electrode plate, thereby causing a decrease in the energy density and cycle life of the battery cell 20. In the embodiment of the present application, by further disposing the sensing segment 2312 of the fiber core 231 between the negative electrode plate 222 and the separator 223, the state of the electrolyte around the negative electrode plate 222 during the charge and discharge cycle can be better dynamically and continuously monitored, which is conducive to a more accurate analysis of the nucleation and growth mechanism of the SEI film.

[0080] In some embodiments, the combination Figure 3 and Figure 4 The input transmission section 2311 may include a first transmission section 2311a and a first transition section 2311b, and the two ends of the first transition section 2311b may be connected to the first transmission section 2311a and the sensing section 2312, respectively. In the direction from the first transmission section 2311a to the sensing section 2312, the diameter d1 of the first transition section 2311b changes from large to small. That is, along the direction from the first transmission section 2311a to the sensing section 2312, the diameters of the first transition section 2311b of the fiber core 231 and the cladding 232 coated on the outer peripheral surface of the first transition section 2311b gradually decrease. The first transition section 2311b is set in a conical shape, and becomes thinner as it approaches the sensing section 2312.

[0081] Correspondingly, the output transmission section 2313 may include a second transmission section 2313a and a second transition section 2313b, and the two ends of the second transition section 2313b may be connected to the second transmission section 2313a and the sensing section 2312, respectively. In the direction from the second transmission section 2313a to the sensing section 2312, the diameter d2 of the second transition section 2313b changes from large to small. That is to say, along the direction from the second transmission section 2313a to the sensing section 2312, the diameters of the second transition section 2313b of the fiber core 231 and the cladding 232 coated on the outer peripheral surface of the second transition section 2313b also gradually decrease. The second transition section 2313b is also set in a conical shape, and becomes thinner as it approaches the sensing section 2312.

[0082] Exemplarily, the optical fiber evanescent wave sensor 23 can be manufactured by using a fused-tapered optical fiber process, so that the first transition section 2311b and the second transition section 2313b can be arranged in a tapered shape.

[0083] In the above technical solution, the transition part where the input transmission segment 2311 and the output transmission segment 2313 of the fiber core 231 are connected to the sensing segment 2312 is set in a conical shape, that is, the closer the input transmission segment 2311 and the output transmission segment 2313 are to the sensing segment 2312, the thinner they are, so that the diameter d3 of the sensing segment 2312 connected between the input transmission segment 2311 and the output transmission segment 2313 is smaller. When the sensing segment 2312 is set in the electrolyte of the battery cell 20, the smaller diameter size can reduce the influence of the sensing segment 2312 on the battery interface, which is conducive to reducing the influence of the sensing segment 2312 in the electrolyte on the performance of the battery cell 20.

[0084] Optionally, the diameter d3 of the sensing segment 2312 may be 50 μm to 250 μm. For example, the diameter d3 of the sensing segment 2312 may be 50 μm, 65 μm, 80 μm, 95 μm, 115 μm, 145 μm, 175 μm, 205 μm, 235 μm, 250 μm, or the value thereof may be within the range obtained by combining any two of the above values.

[0085] Further, the diameter d3 of the sensing segment 2312 may be 70 μm to 150 μm. For example, the diameter d3 of the sensing segment 2312 may be 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, or the value thereof may be within the range obtained by combining any two of the above values.

[0086] It should be understood that when the diameter d3 of the sensing segment 2312 is too small, the sensing segment 2312 may break due to being too thin, resulting in a decrease in the quality reliability of the sensing segment 2312, and the processing difficulty and cost of the too thin sensing segment 2312 are relatively large, which is not conducive to the processing and production of the optical fiber evanescent wave sensor 23. When the diameter d3 of the sensing segment 2312 is too large, the interface resistance of the sensing segment 2312 in the electrolyte is relatively large, which may have an adverse effect on the performance of the battery cell 20. For example, the excessive interface resistance may cause the capacity and cycle life of the battery cell 20 to decrease.

[0087] In the above technical solution, by reasonably setting the diameter size of the sensing segment 2312, on the one hand, it is possible to avoid the sensing segment 2312 from breaking due to being too thin, which is beneficial to ensuring the quality reliability of the sensing segment 2312 and facilitating the processing and production of the optical fiber evanescent wave sensor 23; on the other hand, it is possible to reduce the impact of the sensing segment 2312 on the battery interface, which is beneficial to reducing the impact of the sensing segment 2312 in the electrolyte on the performance of the battery cell 20.

[0088] Optionally, in order to improve the detection sensitivity of the optical fiber evanescent wave sensor 23 to the infrared absorption spectrum of the electrolyte, an absorption enhancement layer (not shown in the figure) can also be provided on the outer peripheral surface of the sensing segment 2312 of the core 231. The absorption enhancement layer can be used to enhance the absorption of the evanescent wave transmitted on the sensing segment 2312 by the electrolyte. Exemplarily, the absorption enhancement layer can be formed by coating, coating or deposition on the outer peripheral surface of the sensing segment 2312 using an active substance capable of enhancing infrared absorption. The active substance can be, for example, but not limited to, graphite, graphene, graphene oxide, polydopamine or metal nanoparticles such as silver.

[0089] It should be understood that the embodiment of the present application does not impose any special restrictions on the specific thickness of the absorption enhancement layer, which can be adjusted according to actual production and design requirements. In one possible example, the thickness of the absorption enhancement layer can be 40nm to 100nm. For example, the thickness of the absorption enhancement layer can be 40nm, 60nm, 80nm, 100nm, or its value can be within the range obtained by combining any two of the above values.

[0090] Optionally, in the optical fiber evanescent wave sensor 23, the core 231 may include any one of a sulfur-containing compound, a selenium-containing compound, a tellurium-containing compound, and a silicon-containing compound.

[0091] It should be understood that the optical fiber evanescent wave sensor 23 may be a chalcogenide optical fiber or a silica-based optical fiber. When the optical fiber evanescent wave sensor 23 is a chalcogenide optical fiber, the core 231 may include a compound containing chalcogen elements (sulfur, tellurium, and selenium); when the optical fiber evanescent wave sensor 23 is a silica-based optical fiber, the core 231 may include a compound containing silicon, for example, the core 231 may include silicon dioxide.

[0092] In the above technical solution, since sulfur-based optical fiber and silicon-based optical fiber have good corrosion resistance, the optical fiber evanescent wave sensor 23 uses sulfur-based optical fiber or silicon-based optical fiber, which can have good resistance to electrolyte corrosion. This is conducive to preventing the optical fiber evanescent wave sensor 23 from being corroded by electrolyte, and further helps to ensure the reliability of the optical fiber evanescent wave sensor 23.

[0093] See again Figures 1 to 5 The battery cell 20 provided in the embodiment of the present application includes a shell 21, an electrode assembly 22, an optical fiber evanescent wave sensor 23 and an electrolyte. The shell 21 includes a shell 211 and a cover plate 212, and the cover plate 212 covers the opening surface of the shell 211 and is connected to the shell 211 to form a closed cavity for placing the electrode assembly 22. The electrolyte is contained in the cavity and wets the electrode assembly 22. The electrode assembly 22 includes a positive electrode sheet 221, a negative electrode sheet 222, and an isolation film 223 disposed between the positive electrode sheet 221 and the negative electrode sheet 222. The optical fiber evanescent wave sensor 23 adopts a sulfur-based optical fiber. Among them, the optical fiber evanescent wave sensor 23 includes a core 221 and a cladding 222, the core 221 includes an input transmission segment 2311, a sensing segment 2312 and an output transmission segment 2313 connected in sequence, and the cladding 232 is coated on the outer peripheral surface of the input transmission segment 2311 and the output transmission segment 2313. The sensing segment 2312 is arranged between the negative electrode plate 222 and the isolation film 223. One end of the input transmission segment 2311 and the output transmission segment 2313 are both arranged in the electrolyte and are respectively connected to the two ends of the sensing segment 2312. The other ends of the input transmission segment 2311 and the output transmission segment 2313 pass through the cover plate 212 and extend to the outside of the housing 21. The input transmission segment 2311 is used to receive the incident infrared laser and transmit the incident infrared laser to the sensing segment 2312. The sensing segment 2312 is used to transmit part of the energy of the incident infrared laser to the electrolyte in the form of an evanescent wave, and then transmit the outgoing infrared laser to the output transmission segment 2313. The output transmission segment 2313 is used to output the outgoing infrared laser transmitted by the sensing segment 2312, so as to analyze and process the outgoing infrared laser.

[0094] In the above technical solution, by setting the sensing segment 2312 of the core 231 in the optical fiber evanescent wave sensor 23 between the negative electrode plate 222 and the isolation membrane 223, the core 231 can directly contact the electrolyte around the negative electrode plate 222 without passing through the cladding 232. In this way, when the incident infrared laser is transmitted to the sensing segment 2312 of the core 231, the evanescent wave generated by the incident infrared laser can be absorbed by the electrolyte around the negative electrode plate 222, so that by analyzing and processing the outgoing infrared laser and the incident infrared laser output by the optical fiber evanescent wave sensor 23, the information of the infrared absorption spectrum of the evanescent wave absorbed by each component in the electrolyte can be obtained, so that the state of the electrolyte around the negative electrode plate 222 during the charge and discharge cycle can be better dynamically and continuously monitored, which is conducive to a more accurate analysis of the nucleation and growth mechanism of the SEI film.

[0095] The embodiment of the present application further provides a battery 10, comprising the battery cell 20 in the aforementioned embodiments.

[0096] like Figure 6 As shown, in some embodiments, the battery 10 may further include a laser 120 , which may be connected to the fiber optic evanescent wave sensor 23 of the battery cell 20 and used to output incident infrared laser light to the fiber optic evanescent wave sensor 23 of the battery cell 20 .

[0097] In one possible example, combining Figure 3 and Figure 6 , the laser 120 may be directly connected to one end of the input transmission segment 2311 of the fiber core 231 away from the sensing segment 2312, so as to output the incident infrared laser to the input transmission segment 2311. In another possible example, the laser 120 may be connected to one end of the input transmission segment 2311 of the fiber core 231 away from the sensing segment 2312 through other signal transmission optical fibers, so as to output the incident infrared laser to the input transmission segment 2311 through other signal transmission optical fibers.

[0098] It should be understood that the embodiment of the present application does not impose any special restrictions on the specific manner of connecting the laser 120 and the optical fiber evanescent wave sensor 23, which can be adjusted according to actual production and design requirements.

[0099] In some embodiments, continue to refer to Figure 6 The battery 10 may further include a detection component 130, which may be connected to the optical fiber evanescent wave sensor 23 and used to receive the outgoing infrared laser output by the optical fiber evanescent wave sensor 23, so as to analyze and process the outgoing infrared laser.

[0100] It should be understood that the detection component 130 may refer to a device that can receive an emitted infrared laser and analyze and process the emitted infrared laser to obtain an infrared absorption spectrum of the electrolyte.

[0101] In one possible example, combining Figure 3 and Figure 6 , the detection component 130 can be directly connected to the end of the output transmission segment 2313 of the fiber core 231 away from the sensing segment 2312 to receive the outgoing infrared laser output by the output transmission segment 2313. In another possible example, the detection component 130 can be connected to the end of the output transmission segment 2313 of the fiber core 231 away from the sensing segment 2312 through other signal transmission optical fibers to receive the outgoing infrared laser output by the output transmission segment 2313 through other signal transmission optical fibers.

[0102] It should be understood that the embodiment of the present application does not impose any special restrictions on the specific manner of connecting the detection component 130 to the optical fiber evanescent wave sensor 23, and it can be adjusted according to actual production and design requirements.

[0103] For example, Figure 6 As shown, the detection component 130 may include an infrared detector 131, an infrared spectrometer 132 and a computer 133 connected in sequence. The infrared detector 131 may be connected to the optical fiber evanescent wave sensor 23, and specifically, the infrared detector 131 may be connected to the output transmission section 2313 of the fiber core 231 in the optical fiber evanescent wave sensor 23. The infrared detector 131 may be used to receive the outgoing infrared laser output by the optical fiber evanescent wave sensor 23, and generate an electrical signal based on the outgoing infrared laser and then output it to the infrared spectrometer 132. The infrared spectrometer 132 and the computer 133 may be used to obtain information on the infrared absorption spectrum of the electrolyte based on the electrical signal, so as to analyze the molecular structure and content of each component in the electrolyte.

[0104] Specifically, the infrared detector 131 can convert the optical signal of the emitted infrared laser into an electrical signal for reception by the infrared spectrometer 132. The infrared spectrometer 132 can process and analyze the electrical signal in combination with the incident infrared spectrum, obtain the infrared absorption spectrum data of the electrolyte, and send the data to the computer 133. The computer 133 can further process the data, for example, convert the data into a visualized infrared absorption spectrum, and analyze the molecular structure and content of each component in the electrolyte according to the infrared absorption spectrum, so as to realize dynamic and continuous detection of the state of the electrolyte.

[0105] For example, the infrared detector 131 may be a mercury cadmium telluride (MCT) body detector, and the infrared spectrometer 132 may be a Fourier infrared spectrometer, which is not particularly limited in the present application.

[0106] In the above technical solution, the infrared laser output by the optical fiber evanescent wave sensor 23 can be processed and analyzed by the infrared detector 131, infrared spectrometer 132 and computer 133 in the detection component 130, so as to obtain an infrared absorption spectrum reflecting the molecular structure and content changes of each component in the electrolyte, so as to realize dynamic and continuous monitoring of the state of the electrolyte during the charge and discharge cycle.

[0107] In some embodiments, the battery 10 may include multiple battery cells 20 , wherein the optical fiber evanescent wave sensor 23 of each battery cell 20 in the multiple battery cells 20 may be connected to the laser 120 and the detection component 130 .

[0108] In the above technical solution, the laser 120 and the detection assembly 130 can be connected to the optical fiber evanescent wave sensor 23 of each battery cell 20 in the battery 10 , so as to monitor the electrolytes of multiple battery cells 20 in the battery 10 .

[0109] For details about the battery 10, please refer to the above Figure 2 The embodiments shown will not be described in detail here.

[0110] The embodiment of the present application further provides an electrical device, comprising the battery 10 described above, and the battery 10 is used to provide electrical energy to the electrical device.

[0111] For a detailed description of the electrical device, please refer to the description of the relevant parts of the aforementioned embodiments, which will not be repeated here.

[0112] Combination of the above Figures 1 to 6 , describes in detail the device embodiment provided by the embodiment of the present application, and the following is combined with Figure 7 , describing the method embodiments provided in the embodiments of the present application.

[0113] Figure 7 A schematic flow chart of an electrolyte monitoring method 700 provided in an embodiment of the present application is shown. It should be understood that the electrolyte monitoring method 700 can be applied to a battery cell 20, and the parts not described in detail can be referred to the aforementioned embodiments.

[0114] The battery cell 20 may include a housing 21, an optical fiber evanescent wave sensor 23, and an electrolyte. The electrolyte may be contained in the housing 21, and a portion of the optical fiber evanescent wave sensor 23 may be disposed in the electrolyte.

[0115] like Figure 7 As shown, the monitoring method 700 may include:

[0116] S710, the optical fiber evanescent wave sensor 23 can receive incident infrared laser.

[0117] Exemplarily, the fiber optic evanescent wave sensor 23 may receive incident infrared laser light output by a laser.

[0118] S720, the optical fiber evanescent wave sensor 23 can transmit part of the energy of the incident infrared laser to the electrolyte in the form of an evanescent wave, and then output an outgoing infrared laser.

[0119] In the above technical solution, the optical fiber evanescent wave sensor 23 arranged in the electrolyte of the battery cell 20 is used to transmit part of the energy of the incident infrared laser to the electrolyte in the form of an evanescent wave, and then output the incident infrared laser of the remaining energy, that is, output the outgoing infrared laser. By analyzing and processing the outgoing infrared laser and the incident infrared laser, the information of the infrared absorption spectrum of the evanescent wave absorbed by each component in the electrolyte can be obtained. In this way, the decomposition products of the electrolyte can be identified, and the molecular structure and content changes of each component in the electrolyte can be obtained, so that the state of the electrolyte during the charge and discharge cycle can be dynamically and continuously monitored. This is conducive to quantitatively characterizing the residual amount of each component in the electrolyte after the charge and discharge cycle, and to more accurately analyze the decomposition mechanism and kinetic changes of the electrolyte, so as to facilitate timely maintenance of the battery cell 20 when the performance of the battery cell 20 is abnormal, so as to improve the performance of the battery cell 20. In addition, during the monitoring process, the structure of the battery cell 20 remains relatively intact, and the impact on the further charge and discharge cycle of the battery cell 20 is small.

[0120] In some embodiments, the optical fiber evanescent wave sensor 23 may include a core 231 and a cladding 232. The core 231 may include an input transmission segment 2311, a sensing segment 2312, and an output transmission segment 2313 connected in sequence, and the cladding 232 is coated on the outer circumference of the input transmission segment 2311 and the output transmission segment 2313. The sensing segment 2312 may be disposed in the electrolyte of the battery cell 20, and at least part of the input transmission segment 2311 and the output transmission segment 2313 may be disposed outside the housing 21.

[0121] At this time, step S710 may specifically include:

[0122] The input transmission section 2311 can receive incident infrared laser light and transmit the incident infrared laser light to the sensing section 2312;

[0123] Step S720 may specifically include:

[0124] The sensing section 2312 can transmit part of the energy of the incident infrared laser to the electrolyte in the form of an evanescent wave, and then transmit the outgoing infrared laser to the output transmission section 2313;

[0125] The output transmission section 2313 can output the emitted infrared laser so as to further analyze and process the emitted infrared laser.

[0126] In the above technical solution, the evanescent wave generated by the incident infrared laser during the transmission process is transmitted to the electrolyte by the sensing segment 2312 in the fiber core 231 which is not covered by the cladding 232 and is absorbed by the electrolyte. Thus, by analyzing and processing the outgoing infrared laser and the incident infrared laser output by the optical fiber evanescent wave sensor 23, the information of the infrared absorption spectrum of the evanescent wave absorbed by each component in the electrolyte can be obtained.

[0127] It should be noted that, under the premise of no conflict, the various embodiments described in this application and / or the technical features in each embodiment can be arbitrarily combined with each other, and the technical solution obtained after the combination should also fall within the protection scope of this application.

[0128] Although the present application has been described with reference to the above embodiments, various modifications may be made thereto and components thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell (20), characterized in that: include: Housing (21), electrolyte and optical fiber evanescent wave sensor (23); The electrolyte is contained in the housing (21), and a portion of the optical fiber evanescent wave sensor (23) is disposed in the electrolyte; The optical fiber evanescent wave sensor (23) is used to receive incident infrared laser light, transmit part of the energy of the incident infrared laser light to the electrolyte in the form of evanescent waves, and then output outgoing infrared laser light.

2. The battery cell (20) according to claim 1, characterized in that: The optical fiber evanescent wave sensor (23) comprises a fiber core (231) and a cladding (232), wherein the fiber core (231) comprises an input transmission segment (2311), a sensing segment (2312) and an output transmission segment (2313) which are connected in sequence, and the cladding (232) is coated on the outer circumference of the input transmission segment (2311) and the output transmission segment (2313); The sensing segment (2312) is arranged in the electrolyte, and the sensing segment (2312) is used to transmit part of the energy of the incident infrared laser to the electrolyte in the form of the evanescent wave, and then output the outgoing infrared laser.

3. The battery cell (20) according to claim 2, characterized in that: At least part of the input transmission section (2311) and the output transmission section (2313) are arranged outside the housing (21); The input transmission section (2311) is used to receive the incident infrared laser and transmit the incident infrared laser to the sensing section (2312); The output transmission segment (2313) is used to output the outgoing infrared laser transmitted by the sensing segment (2312).

4. The battery cell (20) according to claim 2 or 3, characterized in that: The input transmission section (2311) comprises a first transmission section (2311a) and a first transition section (2311b), and two ends of the first transition section (2311b) are respectively connected to the first transmission section (2311a) and the sensing section (2312); The output transmission section (2313) comprises a second transmission section (2313a) and a second transition section (2313b), and two ends of the second transition section (2313b) are respectively connected to the second transmission section (2313a) and the sensing section (2312); Wherein, along the direction from the first transmission section (2311a) to the sensing section (2312), the diameter d1 of the first transition section (2311b) changes from large to small; Along the direction from the second transmission section (2313a) to the sensing section (2312), the diameter d2 of the second transition section (2313b) changes from large to small.

5. The battery cell (20) according to any one of claims 2 to 4, characterized in that: The diameter d3 of the sensing segment (2312) is 50 μm to 250 μm; optionally, the diameter d3 of the sensing segment (2312) is 70 μm to 150 μm.

6. The battery cell (20) according to any one of claims 1 to 5, characterized in that: The fiber core (231) comprises any one of a sulfur-containing compound, a selenium-containing compound, a tellurium-containing compound and a silicon-containing compound.

7. A battery (10), characterized in that: A battery cell (20) comprising the battery cell (20) according to any one of claims 1 to 6.

8. The battery (10) according to claim 7, characterized in that The battery (10) further comprises a laser (120), wherein the laser (120) is connected to the optical fiber evanescent wave sensor (23) of the battery cell (20); The laser (120) is used to output incident infrared laser light to the optical fiber evanescent wave sensor (23).

9. The battery (10) according to claim 7 or 8, characterized in that: The battery (10) further comprises a detection component (130), wherein the detection component (130) is connected to the optical fiber evanescent wave sensor (23) of the battery cell (20); The detection component (130) is used to receive the emitted infrared laser output by the optical fiber evanescent wave sensor (23).

10. The battery (10) according to claim 9, characterized in that The detection assembly (130) comprises an infrared detector (131), an infrared spectrometer (132) and a computer (133) which are connected in sequence, and the infrared detector (131) is connected to the optical fiber evanescent wave sensor (23); The infrared detector (131) is used to receive the emitted infrared laser output by the optical fiber evanescent wave sensor (23), generate an electrical signal based on the emitted infrared laser, and then output the electrical signal to the infrared spectrometer (132); The infrared spectrometer (132) and the computer (133) are used to obtain information on the infrared absorption spectrum of the electrolyte of the battery cell (20) based on the electrical signal.

11. An electrical device, characterized in that: A battery (10) comprising the battery (10) according to any one of claims 7 to 10.

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