Hard-shell battery detection device and system

Abstract

The utility model discloses a hard-shell battery detection device and system, and the device comprises a hard-shell battery provided with a hard battery shell and an air pressure sensor, the air pressure sensor comprises a transmission optical fiber and a pressure-sensitive sensing chip provided with a Fabry-Perot cavity, the transmission optical fiber comprises a first end and a second end, the pressure-sensitive sensing chip is connected with the first end of the transmission optical fiber, and the first end of the transmission optical fiber is connected with the Fabry-Perot cavity; an optical signal is transmitted through the transmission optical fiber, the pressure-sensitive sensing chip is arranged in the hard battery shell, and the second end of the transmission optical fiber is led out to the outer side of the hard battery shell. According to the embodiment of the invention, in the working process of the hard-shell battery, when gas in the hard-shell battery is changed, the internal air pressure is changed, the Fabry-Perot cavity in the pressure-sensitive sensing chip is deformed, the optical signal returned by the pressure-sensitive sensing chip is changed, and the corresponding air pressure signal is determined by analyzing the optical signal returned by the pressure-sensitive sensing chip; and the gas variation in the hard battery can be determined according to the gas pressure signal, so that the in-situ detection of the gas variation in the hard battery is realized.

Description

Technical Field

[0001] This application relates to the field of battery monitoring, and more specifically, to a hard-shell battery detection device and system. Background Art

[0002] With the continuous expansion of the lithium-ion battery market scale, more stringent requirements are put forward for battery safety and reliability. During the operation of a lithium-ion battery, due to the internal chemical reactions, gaseous by-products are usually generated. The generation of gas inside the battery can reflect the working state of the battery, affect the performance of the battery, and even a large amount of gas generation may cause safety risks.

[0003] Therefore, the accurate monitoring of the gas generation amount during the operation of the battery can not only obtain the health status of the battery, but also serve as a safety warning signal. Therefore, there is an urgent need for a device that can detect the gas generation of the battery. Summary of the Utility Model

[0004] This application provides a hard-shell battery detection device and system, which can realize in-situ detection of the gas change amount inside the hard-shell battery through a pressure sensor.

[0005] In a first aspect, an embodiment of this application provides a hard-shell battery detection device, including: a hard-shell battery with a hard battery case and a pressure sensor;

[0006] The pressure sensor includes a transmission optical fiber and a pressure-sensitive sensing chip provided with a Fabry-Perot cavity. Among them, the transmission optical fiber includes a first end and a second end. The pressure-sensitive sensing chip is connected to the first end of the transmission optical fiber and transmits optical signals through the transmission optical fiber;

[0007] The pressure-sensitive sensing chip is placed inside the hard battery case;

[0008] The second end of the transmission optical fiber is led out to the outside of the hard battery case.

[0009] The hard-shell battery detection device provided by the embodiment of the present application includes a hard-shell battery with a rigid battery case and a pressure sensor. The pressure sensor includes a transmission optical fiber and a pressure-sensitive sensing chip provided with a Fabry-Perot cavity. Among them, the transmission optical fiber includes a first end and a second end. The pressure-sensitive sensing chip is connected to the first end of the transmission optical fiber and transmits an optical signal through the transmission optical fiber. The pressure-sensitive sensing chip is placed inside the rigid battery case, and the second end of the transmission optical fiber is led out to the outside of the rigid battery case. According to the embodiment of the present application, during the operation of the battery, an optical signal is transmitted to the pressure-sensitive sensing chip arranged inside the battery through the transmission optical fiber. When gas is generated or absorbed inside the battery, the internal pressure of the battery will change, which will cause the deformation of the Fabry-Perot cavity in the pressure-sensitive sensing chip, and then cause the change of the optical signal returned inside the pressure-sensitive sensing chip. The change of this optical signal is transmitted to the optical fiber demodulation system outside the battery through the transmission optical fiber. By analyzing the optical signal through the optical fiber demodulation system, the internal pressure signal of the battery can be determined, and then the gas change amount inside the battery can be determined according to the pressure signal, so as to realize the in-situ detection of the gas change amount inside the battery.

[0010] As a possible implementation, the rigid battery case is formed by joining a case body and a case cover;

[0011] The case cover is provided with a through hole;

[0012] The second end of the transmission optical fiber is led out to the outside of the rigid battery case, including:

[0013] The second end of the transmission optical fiber is led out to the outside of the rigid battery case through the through hole.

[0014] Through the technical solution of the above implementation, the second end of the transmission optical fiber can be led out to the outside of the rigid battery case through the through hole on the case cover, and the influence on the overall battery is small.

[0015] As a possible implementation, the distance between the pressure-sensitive sensing chip and the bottom of the case cover is greater than or equal to 1 millimeter.

[0016] Through the technical solution of the above implementation, by arranging the pressure-sensitive sensing chip at a certain distance below the through hole from the bottom of the case cover, it is possible to sense the internal pressure change of the battery while avoiding being squeezed by the case cover, thus ensuring the accuracy of the detection result.

[0017] As a possible implementation, the pressure sensor further includes: a protection tube;

[0018] The connection between the pressure-sensitive sensing chip and the first end of the transmission optical fiber includes:

[0019] The pressure-sensitive sensing chip is connected to the first end of the transmission optical fiber through the protection tube.

[0020] Through the technical solution of the above implementation method, a reliable connection between the piezoresistive sensing chip and the transmission optical fiber can be achieved through the protective tube, reducing the connection difficulty between the piezoresistive sensing chip and the transmission optical fiber.

[0021] As a possible implementation method, the material of the protective tube is the same as that of the transmission optical fiber.

[0022] Through the technical solution of the above implementation method, the protective tube and the transmission optical fiber are more matched.

[0023] As a possible implementation method, the protective tube includes a first end and a second end;

[0024] The piezoresistive sensing chip is connected to the first end of the transmission optical fiber through the protective tube, including:

[0025] The first end of the transmission optical fiber penetrates into the protective tube from the second end of the protective tube and penetrates out of the first end of the protective tube;

[0026] The first end of the transmission optical fiber is connected to the piezoresistive sensing chip through the first end of the protective tube;

[0027] Through the technical solution of the above implementation method, the connection between the protective tube and the piezoresistive sensing chip and the transmission optical fiber is more convenient.

[0028] As a possible implementation method, the part of the transmission optical fiber inside the protective tube is sealed with glue between the inner side wall of the protective tube.

[0029] Through the technical solution of the above implementation method, a reliable connection between the transmission optical fiber and the protective tube is achieved.

[0030] As a possible implementation method, the second end of the transmission optical fiber remains outside the second end of the protective tube;

[0031] The second end of the transmission optical fiber is led out to the outside of the hard battery case, including:

[0032] The second end of the protective tube is led out to the outside of the hard battery case through the through hole.

[0033] As a possible implementation method, the second end of the protective tube is sealed with the through hole by sealing glue.

[0034] Through the technical solution of the above implementation method, the sealing performance of the hard shell battery is ensured.

[0035] In a second aspect, an embodiment of the present application provides a hard shell battery detection system, including: a battery testing device, an optical fiber demodulation device, and the hard shell battery detection device according to any one of the first aspect;

[0036] The battery testing device is electrically connected to the positive electrode and the negative electrode of the hard shell battery and is used to set the hard shell battery to a working state;

[0037] The fiber optic demodulation device is connected to the second end of the transmission optical fiber, and is used to transmit an incident optical signal to the pressure-sensitive sensing chip inside the hard-shell battery through the transmission optical fiber, receive the reflected optical signal returned by the pressure-sensitive sensing chip based on the incident optical signal through the transmission optical fiber, analyze the reflected optical signal through a preset logic, determine the corresponding air pressure signal, and determine the gas change amount inside the hard-shell battery according to the air pressure signal.

[0038] In the hard-shell battery detection system provided by the embodiments of the present application, the hard-shell battery is set to a working state through the battery test device. During the working process of the hard-shell battery, the fiber optic demodulation device transmits an incident optical signal to the pressure-sensitive sensing chip with a Fabry-Perot cavity provided inside the hard-shell of the hard-shell battery through the transmission optical fiber, and receives the reflected optical signal returned by the pressure-sensitive sensing chip based on the first signal through the transmission optical fiber. When gas is generated inside the battery, the internal air pressure will increase, which will cause the Fabry-Perot cavity in the pressure-sensitive sensing chip provided inside it to deform, and then the reflected optical signal returned by the pressure-sensitive sensing chip will change. The fiber optic demodulation device analyzes the reflected optical signal returned by the pressure-sensitive sensing chip to determine the corresponding air pressure signal, and the gas change amount inside the hard-shell battery can be determined according to the air pressure signal, so as to realize the in-situ detection of the gas change amount inside the hard-shell battery. Description of the Drawings

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced below. Obviously, the following described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the drawings.

[0040] Figure 1 It is a schematic structural diagram of a hard-shell battery detection device provided by some embodiments of the present application;

[0041] Figure 2 It is a schematic flowchart of a hard-shell battery detection method provided by an embodiment of the present application;

[0042] Figure 3 It is a schematic diagram of a hard-shell battery detection system provided by an embodiment of the present application;

[0043] Figure 4 It is a schematic diagram of a fiber optic demodulation device provided by an embodiment of the present application.

[0044] In the drawings, the drawings are not drawn to actual scale. Detailed Embodiments

[0045] To make the objectives, technical solutions and advantages of the embodiments of this application clearer, the following will clearly describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the scope of protection of this application.

[0046] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used in the description of the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the description of the specification, claims and drawings of this application are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description of the specification, claims or drawings of this application are used to distinguish different objects and are not used to describe a specific order or primary-secondary relationship.

[0047] Referring to "embodiments" in this application means that specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appearing in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0048] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to", and "attached" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0049] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally represents an "or" relationship between the associated objects before and after.

[0050] In the embodiments of this application, the same reference numerals represent the same components. For the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thicknesses, lengths, widths and other dimensions of various components shown in the drawings in the embodiments of this application, as well as the overall thickness, length, width and other dimensions of the integrated device are only illustrative and should not constitute any limitation to this application.

[0051] In this application, "a plurality of" means two or more (including two).

[0052] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, etc., and the embodiments of this application do not limit this. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, and the embodiments of this application also do not limit this.

[0053] Currently, the main method for detecting battery gas production is to measure the difference in weight in a liquid before and after battery gas production, and then calculate the volume change of the battery according to Archimedes' principle, and measure the gas production volume based on the volume change of the whole battery. However, in fact, there is usually a certain residual space inside the battery, especially for hard-shell batteries. Therefore, the volume change will not be immediately caused at the initial stage of gas production. Therefore, this method cannot provide the gas production change information before the deformation of the battery case. In addition, this method also requires the battery to be placed in water throughout the process, and it is impossible to accurately change the working temperature conditions of the battery, which limits its application range.

[0054] In addition, there is currently a device for detecting battery gas production. This device winds a pressure sensor around a metal rod that can be welded to the battery top cover as a whole, places the metal rod in the cavity in the center of the battery core. At the same time, the pressure sensor is electrically connected to a pressure recorder outside the case through a connecting wire to obtain the real-time pressure change inside the battery, so as to monitor the gas production volume inside the battery. However, this method requires introducing an additional metal rod to carry the pressure sensor. Since complex electrochemical reactions occur during the operation of the battery and corrosive gases such as HF are generated, it is extremely easy to cause corrosion of the metal rod, affecting the reliability of the sensor. In addition, the pressure sensor transmits data through the electrical connection with the pressure recorder, which will generate electromagnetic interference with the electrical connection components inside the battery itself. Moreover, the metal rod used in this device needs to be placed through the central hole space of the cylindrical core and cannot be extended to square hard-shell battery cores.

[0055] To solve the above problems, the embodiments of this application provide a hard-shell battery detection device, method, and system.

[0056] First, the hard-shell battery detection device provided by the embodiments of this application will be introduced below.

[0057] See Figure 1 , which is a schematic structural diagram of a hard-shell battery detection device provided by the embodiments of this application. As Figure 1 shown, the hard-shell battery detection device provided by the embodiments of this application may include: a hard-shell battery with a rigid battery case 100 and a barometric pressure sensor.

[0058] 。Generally, a hard shell battery further includes an electric core disposed inside the rigid battery case 100.

[0059] The air pressure sensor includes a transmission optical fiber 110 and a pressure-sensitive sensing chip 120 provided with a Fabry-Perot cavity (hereinafter referred to as the pressure-sensitive sensing chip 120). Among them, the transmission optical fiber 110 includes a first end and a second end. The pressure-sensitive sensing chip 120 is connected to the first end of the transmission optical fiber 110 and transmits an optical signal through the transmission optical fiber 110.

[0060] Generally, the transmission optical fiber 110 includes two ends. Any one of the two ends can be used as the first end, and the other end except the first end can be used as the second end.

[0061] The pressure-sensitive sensing chip 120 is a sensing chip sensitive to air pressure.

[0062] The pressure-sensitive sensing chip 120 is placed inside the rigid battery case 100.

[0063] The second end of the transmission optical fiber 110 is led out to the outside of the rigid battery case 100.

[0064] The hard shell battery detection device provided by the embodiment of the present application includes a hard shell battery provided with a rigid battery case and an air pressure sensor. The air pressure sensor includes a transmission optical fiber and a pressure-sensitive sensing chip provided with a Fabry-Perot cavity. Among them, the transmission optical fiber includes a first end and a second end. The pressure-sensitive sensing chip is connected to the first end of the transmission optical fiber and transmits an optical signal through the transmission optical fiber. The pressure-sensitive sensing chip is placed inside the rigid battery case, and the second end of the transmission optical fiber is led out to the outside of the rigid battery case. According to the embodiment of the present application, during the operation of the battery, an optical signal is transmitted to the pressure-sensitive sensing chip disposed inside the battery through the transmission optical fiber. When gas is generated or absorbed inside the battery, the air pressure inside the battery will change, thereby causing the deformation of the Fabry-Perot cavity in the pressure-sensitive sensing chip, and further causing the change of the optical signal returned inside the pressure-sensitive sensing chip. The change of the optical signal is transmitted to the optical fiber demodulation system outside the battery through the transmission optical fiber. The optical signal is analyzed by the optical fiber demodulation system to determine the corresponding air pressure signal. According to the air pressure signal, the gas change amount inside the battery can be determined, so as to realize the in-situ detection of the gas change amount inside the battery.

[0065] In a possible implementation manner, the pressure-sensitive sensing chip provided with a Fabry-Perot cavity can be an optical fiber pressure sensing chip manufactured based on the Fabry-Perot (abbreviated as Fabry-Perot) interference principle and MEMS (Micro Electromechanical System) technology, and its material can be silicon-glass or Si-Si material.

[0066] Through the technical solution of the above implementation method, the pressure-sensitive sensor chip has the advantages of being insensitive to electromagnetics, small size, reliable measurement, high precision and corrosion resistance, and has little impact on the operation of the battery body.

[0067] In a possible implementation, the transmission optical fiber can be a communication pigtail, one end of which is a connector and the other end is a fiber optic cut end. When connected to the pressure-sensitive sensor chip, the fiber optic cut end can be used as the first end and the connector can be used as the second end. The connector is a connector that can be connected to an external device (such as an optical fiber demodulation device, etc.).

[0068] Through the technical solution of the above implementation method, the pressure-sensitive sensor chip can be directly connected to external devices such as an optical fiber demodulation device through a transmission optical fiber.

[0069] In one possible implementation, Figure 1 As shown, the hard battery case 100 can be formed by joining a shell 101 and a shell cover 102. The shell 101 and the shell cover 102 are both made of a hard material, such as aluminum. The shell 101 can be provided with an upward opening, and the shell cover 102 can be covered on the upward opening of the shell 101, so that the two are joined to form the hard battery case 100.

[0070] The shell cover 102 may be provided with a through hole 1021 , and the second end of the transmission optical fiber 110 may be led out to the outside of the hard battery shell 100 through the through hole 1021 on the shell cover 102 .

[0071] Among them, the aperture of the through hole 1021 opened on the shell cover 102 can be equal to or greater than the diameter of the transmission optical fiber 110 to ensure that the second end of the transmission optical fiber 110 can be led out to the outside of the hard battery shell 100 through the through hole 1021.

[0072] Furthermore, in one example, Figure 1 As shown, the shell cover 102 may also be provided with a positive pole 1022, a negative pole 1023, an explosion-proof valve 1024, a liquid injection hole 1025, etc. The through hole 1021 should bypass the other structures on the shell cover 102 as described above.

[0073] Through the technical solution of the above-mentioned implementation method, the second end of the transmission optical fiber can be led out to the outside of the hard battery shell through the through hole on the shell cover, which has little impact on the battery as a whole.

[0074] In one possible implementation, the pressure-sensitive sensor chip is disposed inside the hard battery shell, and the distance between the pressure-sensitive sensor chip and the bottom of the shell cover may be greater than or equal to 1 mm.

[0075] Through the technical solution of the above implementation method, by setting the pressure-sensitive sensing chip at a certain distance below the through hole from the bottom of the shell cover, it is possible to sense the internal air pressure change of the battery while avoiding being squeezed by the shell cover, thereby ensuring the accuracy of the detection result.

[0076] Furthermore, in order to avoid the pressure-sensitive sensing chip being squeezed by structures such as the internal battery cells of the hard shell battery, the pressure-sensitive sensing chip also has a certain distance from other structures inside the hard shell battery, and the specific distance can be set according to actual needs.

[0077] Furthermore, in order to minimize the length of the transmission optical fiber, the pressure-sensitive sensing chip can be set near the edge below the through hole.

[0078] In a possible implementation method, because the diameter of the transmission optical fiber is small, usually between 25 - 250um, there is a large gap between its size and that of the pressure-sensitive sensing chip, so it is very difficult to directly connect with the pressure-sensitive sensing chip. Therefore, in order to facilitate the connection between the pressure-sensitive sensing chip and the transmission optical fiber, the air pressure sensor can also include: a protective tube.

[0079] The pressure-sensitive sensing chip can be connected to the first end of the transmission optical fiber through the protective tube.

[0080] The material of the protective tube can be the same as that of the transmission optical fiber, such as quartz. In this way, the protective tube can be more matched with the transmission optical fiber.

[0081] Through the technical solution of the above implementation method, a reliable connection between the pressure-sensitive sensing chip and the transmission optical fiber can be achieved through the protective tube, reducing the connection difficulty between the pressure-sensitive sensing chip and the transmission optical fiber.

[0082] The protective tube can include two ends, the first end and the second end. When connecting the first end of the transmission optical fiber to the pressure-sensitive sensing chip, the first end of the transmission optical fiber can be inserted from the second end of the protective tube and pass out from the first end of the protective tube, and then the first end of the transmission optical fiber can be connected to the pressure-sensitive sensing chip through the first end of the protective tube.

[0083] To facilitate connecting the first end of the transmission optical fiber to the pressure-sensitive sensing chip through the first end of the protective tube, the first end of the transmission optical fiber can be flush with the first end of the protective tube. In this way, by connecting the first end of the protective tube to the pressure-sensitive sensing chip, the connection between the first end of the transmission optical fiber and the pressure-sensitive sensing chip is achieved.

[0084] In an example, the shape of the first end of the protective tube can match the shape of the pressure-sensitive sensing chip. Among them, the shape of the pressure-sensitive sensing chip can be circular or polygonal, etc. In this way, it is more convenient to connect the first end of the protective tube to the pressure-sensitive sensing chip.

[0085] In one example, the thickness of the pressure-sensitive sensing chip can be any size between 1 - 5 mm. When the shape of the pressure-sensitive sensing chip is a polygon, its side length can be any size between 1 - 10 mm. Through experiments, it is determined that the above sizes can ensure the structure of the pressure-sensitive sensing chip matches the battery cell and meet the range and sensitivity requirements of the battery air pressure test.

[0086] In one example, the first end of the protection tube and the pressure-sensitive sensing chip can be connected by adhesive pasting. For example, ultraviolet light-curing adhesive can be used for adhesive pasting. Ultraviolet light-curing adhesive has advantages such as good solidification, reliable and portable operation. Low-melting-point glass can also be used for adhesive pasting.

[0087] In one example, to facilitate the insertion of the first end of the transmission optical fiber into the protection tube, the inner diameter of the protection tube can be equal to or greater than the diameter of the transmission optical fiber, so that the transmission optical fiber can be inserted into the protection tube. The diameter of the transmission optical fiber can be the core diameter of the transmission optical fiber or the total diameter of the core and the cladding.

[0088] In one example, when connecting the transmission optical fiber and the pressure-sensitive sensing chip through the protection tube, a part of the transmission optical fiber will remain inside the protection tube. The part of the transmission optical fiber remaining inside the protection tube and the inner side wall of the protection tube can be sealed with glue. Through sealing, reliable connection between the two can be achieved. Among them, the sealing glue used can be epoxy resin, PET glue, ultraviolet light-curing glue, etc.

[0089] In one example, the height of the protection tube can be 1 - 50 mm. Through experiments, it is determined that the above size can meet the range and sensitivity requirements of the battery air pressure test.

[0090] Furthermore, when connecting the transmission optical fiber and the pressure-sensitive sensing chip through the protection tube, the second end of the transmission optical fiber can remain outside the second end of the protection tube. Based on this, the second end of the protection tube can be led out to the outside of the rigid battery case through the through-hole on the rigid battery case cover. Since the second end of the transmission optical fiber remains outside the second end of the protection tube, leading the second end of the protection tube to the outside of the rigid battery case also ensures that the second end of the transmission optical fiber is led out to the outside of the rigid battery case. Correspondingly, the diameter of the through-hole on the cover needs to be equal to or greater than the diameter of the second end of the protection tube.

[0091] After the second end of the protection tube passes through the through-hole, it can be sealed with glue between it and the through-hole. The sealing glue used can be ultraviolet light-curing glue, epoxy resin glue, polyacrylic acid glue, etc.

[0092] Through the technical solution of the above implementation method, by sealing the protection tube and the through-hole, the sealing performance of the hard-shell battery is ensured, and it can also prevent the protection tube from moving in the through-hole.

[0093] In a possible implementation, the size of the through hole in the hard battery case cover can also match the size of the piezoresistive sensing chip. This implementation can facilitate inserting the piezoresistive sensing chip into the battery from the outside after the battery is formed, and also facilitate replacing the piezoresistive sensing chip subsequently.

[0094] Based on the hard-shell battery detection device provided in the above embodiments, correspondingly, the embodiments of the present application also provide a hard-shell battery detection method, which is applied to the hard-shell battery detection device provided in the above embodiments.

[0095] See Figure 2 , which is a schematic flowchart of a hard-shell battery detection method provided by an embodiment of the present application. As Figure 2 shown, the hard-shell battery detection method provided by the embodiments of the present application may include the following steps:

[0096] S21. During the operation of the hard-shell battery, an incident optical signal is transmitted to the piezoresistive sensing chip through a transmission optical fiber.

[0097] In one example, the transmission optical fiber can be led out to the second end outside the hard-shell battery and connected to an optical fiber demodulation device, and the incident optical signal is provided by a light source arranged in the optical fiber demodulation device.

[0098] S22. Receive the reflected optical signal returned by the piezoresistive sensing chip based on the incident optical signal through the transmission optical fiber.

[0099] In one example, after receiving the incident optical signal, the piezoresistive sensing chip reflects the incident optical signal to obtain the reflected optical signal.

[0100] S23. Analyze the reflected optical signal to obtain the corresponding air pressure signal.

[0101] In one example, the transmission optical fiber can transmit the reflected optical signal to the optical fiber demodulation device connected thereto, and then the optical fiber demodulation device can use a preset logic to analyze the reflected optical signal to obtain the corresponding air pressure signal, and this air pressure signal can reflect the air pressure value inside the battery.

[0102] During the operation of the battery, when gas is generated or absorbed inside, the air pressure inside the battery will change. Usually, the air pressure will increase when gas is generated, and the air pressure will decrease when gas is absorbed. The change in air pressure will cause the Fabry-Perot cavity in the piezoresistive sensing chip arranged inside the battery to deform, and further cause the reflected optical signal reflected by the piezoresistive sensing chip to change. Therefore, by analyzing the reflected optical signal, the corresponding air pressure signal can be determined.

[0103] S24. Determine the gas change amount inside the hard-shell battery according to the air pressure signal.

[0104] The change in the air pressure signal is usually related to the change in the amount of gas inside the battery. Therefore, when determining the change in the air pressure inside the battery based on the air pressure signal obtained in S23, the change in the air pressure signal can be determined according to the actual requirements first, and then the change in the gas amount can be determined based on the change in the air pressure signal.

[0105] In one example, the correlation between the change in the air pressure signal and the change in the gas amount inside the battery can be determined in advance through experiments or other means. Then, after determining the change in the air pressure signal, the corresponding change in the gas amount can be determined based on this correlation.

[0106] A hard-shell battery detection method provided by an embodiment of the present application. During the operation of the hard-shell battery, an incident optical signal is transmitted through an optical fiber to a pressure-sensitive sensing chip provided with a Fabry-Perot cavity inside the hard shell of the hard-shell battery. When gas is generated inside the battery, the internal air pressure will increase, causing the Fabry-Perot cavity in the pressure-sensitive sensing chip provided inside it to deform, and then causing the reflected optical signal returned by the pressure-sensitive sensing chip to change. By analyzing the reflected optical signal returned by the pressure-sensitive sensing chip, the corresponding air pressure signal is determined, and the change in the gas amount inside the hard-shell battery can be determined based on the air pressure signal, thereby realizing the in-situ detection of the change in the gas amount inside the hard-shell battery.

[0107] Based on the hard-shell battery detection device provided in the above embodiment, correspondingly, an embodiment of the present application also provides a hard-shell battery detection system.

[0108] See Figure 3 , which is a schematic diagram of a hard-shell battery detection system provided by an embodiment of the present application. As Figure 3 shown, the hard-shell battery detection system provided by an embodiment of the present application may include: a battery test device 300, an optical fiber demodulation device 310, and the hard-shell battery detection device 320 provided in the above embodiment.

[0109] The hard-shell battery detection device 320 includes a hard-shell battery and a pressure sensor, and its specific structure can be referred to the description of the above embodiment, which will not be elaborated here.

[0110] Among them, the battery test device 300 can be electrically connected to the positive and negative electrodes of the hard-shell battery through electrical connection lines, and is used to set the hard-shell battery to a working state. The function of the battery test device 300 is to make the hard-shell battery enter the working state, and it can adopt existing mature battery charge and discharge test devices, such as a charge and discharge machine.

[0111] The fiber optic demodulation device 310 is connected to the second end of the transmission optical fiber 321 of the barometric pressure sensor, and is configured to transmit an incident optical signal to the pressure-sensitive sensing chip inside the hard-shell battery through the transmission optical fiber 321, receive the reflected optical signal returned by the pressure-sensitive sensing chip through the transmission optical fiber 321, analyze the reflected optical signal through a preset logic to obtain a corresponding barometric pressure signal, and then determine the gas change amount inside the hard-shell battery according to the change of the barometric pressure signal.

[0112] In the hard-shell battery detection system provided by the embodiments of the present application, the hard-shell battery is set to a working state through a battery testing device. During the working process of the hard-shell battery, the fiber optic demodulation device transmits an incident optical signal to the pressure-sensitive sensing chip provided with a Fabry-Perot cavity inside the hard-shell of the hard-shell battery through the transmission optical fiber, and receives the reflected optical signal returned by the pressure-sensitive sensing chip based on the first signal through the transmission optical fiber. When gas is generated inside the battery, the internal air pressure will increase, which will cause the Fabry-Perot cavity in the pressure-sensitive sensing chip provided inside it to deform, and then cause the reflected optical signal returned by the pressure-sensitive sensing chip to change. The fiber optic demodulation device determines the corresponding barometric pressure signal by analyzing the reflected optical signal returned by the pressure-sensitive sensing chip, and can determine the gas change amount inside the hard-shell battery according to the change of the barometric pressure signal, so as to realize the in-situ detection of the gas change amount inside the hard-shell battery.

[0113] In a possible implementation manner, as Figure 4 shown, the fiber optic demodulation device may include: a light source 401, a coupler 402, a demodulation module 403, and a computer 404.

[0114] Among them, the light source 401 and the demodulation module 403 are respectively connected to the coupler 402, and the demodulation module 403 is also connected to the computer 404.

[0115] When applying this fiber optic demodulation device to the hard-shell battery detection system provided in the above embodiments, the coupler 402 may be connected to the second end of the transmission optical fiber of the barometric pressure sensor in the hard-shell battery detection device, so that the light source 401 can transmit an incident optical signal to the pressure-sensitive sensing chip through the transmission optical fiber, and the reflected optical signal returned by the pressure-sensitive sensing chip based on the incident optical signal can be transmitted to the demodulation module 403. The demodulation module 403 is built-in with a preset analysis logic, and the corresponding barometric pressure signal can be obtained by analyzing the received reflected optical signal through the preset analysis logic, and then the barometric pressure signal is transmitted to the computer 404, and the computer 404 can determine the gas change amount inside the hard-shell battery according to the barometric pressure signal.

[0116] In one example, the computer 404 may compare and calculate the air pressure signal output by the demodulation module 403 with the previously collected or set air pressure signal according to actual requirements, determine the change amount of the air pressure signal, and then determine the change amount of the gas inside the hard-shell battery corresponding to the determined change amount of the air pressure signal based on the preset correlation between the change amount of the air pressure signal and the change amount of the gas inside the battery.

[0117] For example, when it is necessary to determine the change amount of the gas in the hard-shell battery from the time of factory to the current detection time, the air pressure signal output by the demodulation module 403 may be compared and calculated with the initial air pressure signal measured at the time of battery factory, and then the change amount of the gas in the hard-shell battery from the time of factory to the current time can be determined according to the calculated change amount of the air pressure.

[0118] For another example, when it is necessary to determine the change amount of the gas in the hard-shell battery from the previous detection time to the current detection time, the air pressure signal output by the demodulation module 403 may be compared and calculated with the air pressure signal measured at the previous detection time, and then the change amount of the gas in the hard-shell battery from the previous detection time to the current detection time can be determined according to the calculated change amount of the air pressure.

[0119] The parsing logic built in the demodulation module 403 is used to obtain the corresponding air pressure signal according to the reflected light signal, and this logic can be set according to the results of multiple experiments, experience or theoretical calculations. For example, it can be set after multiple experimental calibrations according to the performance of different sensors.

[0120] In one example, the above logic may be to determine the deformation amount of the Fabry-Perot cavity according to the change amount of the second signal, and then determine the corresponding air pressure value according to the deformation amount of the Fabry-Perot cavity, and further obtain the corresponding air pressure signal, etc.

[0121] Through the technical solution of the above implementation method, it is possible to realize analyzing the gas production amount inside the hard-shell battery based on the reflected light signal by using the fiber optic demodulation device.

[0122] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A hard-shell battery detection device, characterized in that, it includes: a hard-shell battery with a hard battery case and a barometric pressure sensor; the barometric pressure sensor includes a transmission optical fiber and a pressure-sensitive sensing chip provided with a Fabry-Perot cavity, wherein the transmission optical fiber includes a first end and a second end, the pressure-sensitive sensing chip is connected to the first end of the transmission optical fiber, and transmits an optical signal through the transmission optical fiber; the pressure-sensitive sensing chip is placed inside the hard battery case; the second end of the transmission optical fiber is led out to the outside of the hard battery case.

2. The hard-shell battery detection device according to claim 1, characterized in that, the hard battery case is formed by joining a case body and a case cover; the case cover is provided with a through hole; the second end of the transmission optical fiber is led out to the outside of the hard battery case, including: the second end of the transmission optical fiber is led out to the outside of the hard battery case through the through hole.

3. The hard-shell battery detection device according to claim 2, characterized in that, the distance between the pressure-sensitive sensing chip and the bottom of the case cover is greater than or equal to 1 millimeter.

4. The hard-shell battery detection device according to claim 2, characterized in that, the barometric pressure sensor further includes: a protective tube; the pressure-sensitive sensing chip is connected to the first end of the transmission optical fiber, including: the pressure-sensitive sensing chip is connected to the first end of the transmission optical fiber through the protective tube.

5. The hard-shell battery detection device according to claim 4, characterized in that, the material of the protective tube is the same as that of the transmission optical fiber.

6. The hard-shell battery detection device according to claim 4, characterized in that, the protective tube includes a first end and a second end; the pressure-sensitive sensing chip is connected to the first end of the transmission optical fiber through the protective tube, including: the first end of the transmission optical fiber penetrates into the protective tube from the second end of the protective tube and penetrates out from the first end of the protective tube; the first end of the transmission optical fiber is connected to the pressure-sensitive sensing chip through the first end of the protective tube.

7. The hard-shell battery detection device according to claim 6, characterized in that, the part of the transmission optical fiber inside the protective tube is sealed with the inner side wall of the protective tube by glue.

8. The hard-shell battery detection device according to claim 6, characterized in that, the second end of the transmission optical fiber remains outside the second end of the protective tube; the second end of the transmission optical fiber is led out to the outside of the hard battery case, including: the second end of the protective tube is led out to the outside of the hard battery case through the through hole.

9. The hard-shell battery detection device according to claim 8, characterized in that, the second end of the protective tube is sealed with the through hole by sealing glue.

10. A hard-shell battery detection system, characterized in that, it includes: a battery testing device, an optical fiber demodulation device and the hard-shell battery detection device according to any one of claims 1-9; the battery testing device is electrically connected to the positive electrode and the negative electrode of the hard-shell battery, and is used to set the hard-shell battery to a working state; The optical fiber demodulation device is connected to the second end of the transmission optical fiber, and is configured to transmit an incident optical signal to the pressure-sensitive sensing chip inside the hard-shell battery through the transmission optical fiber, receive a reflected optical signal returned by the pressure-sensitive sensing chip based on the incident optical signal through the transmission optical fiber, analyze the reflected optical signal through a preset logic to determine a corresponding air pressure signal, and determine the gas change amount inside the hard-shell battery according to the air pressure signal.

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