WO2024055209A1

WO2024055209A1 - Hard-shell battery detection device, method, and system

Info

Publication number: WO2024055209A1
Application number: PCT/CN2022/118809
Authority: WO
Inventors: 雷美娜; 林真; 李伟; 王双; 江俊峰
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2022-09-14
Filing date: 2022-09-14
Publication date: 2024-03-21

Abstract

Disclosed in the present application are a hard-shell battery detection device, method, and system. The hard-shell battery detection 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 to the first end of the transmission optical fiber; an optical signal is transmitted by means of 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 of the hard battery shell. According to embodiments of the present application, in a working process of a hard-shell battery, when there is a gas change in the hard-shell battery, the internal air pressure is changed to cause deformation of a Fabry-Perot cavity in a pressure-sensitive sensing chip, and an optical signal returned by the pressure-sensitive sensing chip is changed; the optical signal returned by the pressure-sensitive sensing chip is parsed to determine a corresponding air pressure signal, and the gas change amount in the hard battery can be determined according to the air pressure signal, such that the in-situ detection of the gas change amount in the hard battery is implemented.

Description

Hard shell battery detection device, method and system

Technical field

The present application relates to the field of battery monitoring, and more specifically, to a hard-shell battery detection device, method and system.

Background technique

As the lithium-ion battery market continues to expand, more stringent requirements have been put forward for battery safety and reliability. During the working process of lithium-ion batteries, the internal chemical reactions are usually accompanied by the production of gaseous by-products. The generation of gases in the battery can reflect the working status of the battery and also affect the performance of the battery, and a large amount of gas can even be produced. Will cause security risks.

Therefore, accurate monitoring of gas production during battery operation can not only inform 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 battery gas production.

Contents of the invention

This application provides a hard-shell battery detection device, method and system, which can realize in-situ detection of gas changes inside the hard-shell battery through an air pressure sensor.

In the first aspect, embodiments of the present application provide a hard-shell battery detection device, including: a hard-shell battery provided with a hard battery case and a pressure sensor;

The air pressure sensor includes a transmission optical fiber and a pressure-sensitive sensing chip provided with a Faber cavity. 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 passes through the transmission optical fiber. transmit optical signals;

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.

The hard-shell battery detection device provided by the embodiment of the present application includes a hard-shell battery with a hard 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 Faber cavity, wherein the transmission optical fiber It 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. The pressure-sensitive sensing chip is placed inside the hard battery shell, and the third end of the transmission optical fiber is The two ends are led out to the outside of the hard battery case. According to the embodiment of the present application, during the operation of the battery, optical signals are transmitted to the pressure-sensitive sensing chip provided 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, causing pressure The Faber cavity in the pressure-sensitive sensing chip is deformed, which in turn causes changes in the optical signal returned inside the pressure-sensitive sensing chip. The changes in the optical signal are transmitted to the optical fiber demodulation system outside the battery through the transmission optical fiber, and are demodulated through the optical fiber. The system analyzes the light signal to determine the air pressure signal inside the battery, and then determines the gas change amount inside the battery based on the air pressure signal, thereby achieving in-situ detection of the gas change amount inside the battery.

As a possible implementation method, the hard battery case is composed of a case and a case cover joined to each other;

The shell cover is provided with a through hole;

The second end of the transmission optical fiber is led 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.

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 hard battery case through the through hole on the case cover, which has less impact on the overall battery.

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

Through the technical solution of the above implementation method, by arranging the pressure-sensitive sensing chip under the through hole at a distance from the bottom of the shell cover, it can sense changes in the internal air pressure of the battery while avoiding being squeezed by the shell cover, thereby ensuring Accuracy of test results.

As a possible implementation method, the air pressure sensor also includes: a protection 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 a protective tube.

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, which reduces the difficulty of connecting the pressure-sensitive sensing chip and the transmission optical fiber.

As a possible implementation, the material of the protective tube is the same as the material of the transmission optical fiber.

Through the technical solution of the above implementation method, the protection tube and the transmission optical fiber are better matched.

As a possible implementation manner, the protection 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 a protective tube, including:

The first end of the transmission optical fiber passes through the second end of the protection tube and passes through the first end of the protection 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;

Through the technical solution of the above implementation mode, the connection between the protection tube, the pressure-sensitive sensing chip and the transmission optical fiber is made more convenient.

As a possible implementation, the transmission optical fiber is sealed by glue between the part inside the protective tube and the inner wall of the protective tube.

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

As a possible implementation, the second end of the transmission optical fiber is left outside the second end of the protective tube;

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

As a possible implementation manner, the second end of the protection tube and the through hole are sealed with sealing glue.

Through the technical solution of the above implementation method, the sealing of the hard-shell battery is ensured.

In a second aspect, embodiments of the present application provide a hard-shell battery detection method, which is applied to the hard-shell battery detection device described in any one of the first aspects. The method includes:

During the working process of the hard-shell battery, the incident light signal is transmitted to the pressure-sensitive sensor chip through the transmission optical fiber;

Receive the reflected light signal returned by the pressure-sensitive sensor chip based on the incident light signal through the transmission optical fiber;

Analyze the reflected light signal to obtain the corresponding air pressure signal;

The amount of gas change inside the hard shell battery is determined based on the air pressure signal.

An embodiment of the present application provides a method for detecting a hard-shell battery. During the working process of the hard-shell battery, the transmission optical fiber is used to transmit data to a pressure-sensitive sensing chip provided with a Faber cavity inside the hard shell of the hard-shell battery. The incident light signal, when gas is generated inside the battery, will increase the internal air pressure, causing the Faber cavity in the pressure-sensitive sensing chip installed inside to deform, thereby causing the reflection of the pressure-sensitive sensing chip to return. When the light signal changes, the corresponding air pressure signal can be determined by analyzing the reflected light signal returned by the pressure-sensitive sensor chip. Based on the air pressure signal, the gas change amount in the hard battery can be determined, thereby realizing the detection of the gas inside the hard battery. In-situ detection of changes.

In a third aspect, embodiments of the present application provide a hard-shell battery detection system, including: a battery testing device, an optical fiber demodulation device, and the hard-shell battery detection device described in any one of the first aspects;

The battery testing device is electrically connected to the positive and negative electrodes 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 used to transmit the incident light signal to the pressure-sensitive sensor chip inside the hard-shell battery through the transmission optical fiber, and receive the response signal returned by the pressure-sensitive sensor chip based on the incident light signal through the transmission optical fiber. The reflected light signal is analyzed through preset logic to determine the corresponding air pressure signal, and the gas change amount inside the hard-shell battery is determined based on the air pressure signal.

In the hard-shell battery detection system provided by the embodiment of the present application, the hard-shell battery is set to the working state through the battery testing device. During the working process of the hard-shell battery, the optical fiber demodulation device transmits signals to the hard-shell battery through the transmission optical fiber. The internal pressure-sensitive sensor chip with a Faber cavity transmits the incident light signal, and receives the reflected light signal returned by the pressure-sensitive sensor chip based on the first signal through the transmission optical fiber. When gas is generated inside the battery, it will cause the internal The air pressure increases, causing the Faber cavity in the pressure-sensitive sensing chip installed inside to deform, which in turn causes the reflected light signal returned by the pressure-sensitive sensing chip to change. The optical fiber demodulation device passes the pressure-sensitive sensing The reflected light signal returned by the chip is analyzed to determine the corresponding air pressure signal. Based on the air pressure signal, the gas change amount in the hard battery can be determined, thereby achieving in-situ detection of the gas change amount inside the hard battery.

Description of drawings

In order to explain the technical solutions of the embodiments of the present application more clearly, the drawings required to be used 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. Those of ordinary skill in the art can also obtain other drawings based on the drawings without exerting creative efforts.

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

Figure 2 is a schematic flow chart of a hard-shell battery detection method provided by an embodiment of the present application;

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

Figure 4 is a schematic diagram of an optical fiber demodulation device provided by an embodiment of the present application.

In the drawings, the drawings are not drawn to actual scale.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions 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 Apply for some of the embodiments, not all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the technical field of this application; the terms used in the specification of this application are only for describing specific implementations. The purpose of the examples is not intended to limit the application; the terms "including" and "having" and any variations thereof in the description and claims of the application and the above description of the drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or priority relationship.

Reference in this application to "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

In the description of this application, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection", "connection" and "attachment" should be understood in a broad sense. For example, it can be a fixed connection, It can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between 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.

The term "and/or" in this application is just an association relationship describing related objects, indicating that there can be three relationships, for example, A and/or B, which can mean: A exists alone, A and B exist simultaneously, alone There are three situations B. In addition, the character "/" in this application generally indicates that the related objects are an "or" relationship.

In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of simplicity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length and width of the integrated device, are only illustrative illustrations and should not constitute any limitation to the present application. .

"Plural" appearing in this application means two or more (including two).

In this application, battery cells may include lithium ion secondary battery cells, lithium ion primary battery cells, lithium sulfur battery cells, sodium lithium ion battery cells, sodium ion battery cells or magnesium ion battery cells, etc., The embodiments of the present application are not limited to this. The battery cell may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes, and the embodiments of the present application are not limited to this.

The current way to detect battery gas production is to measure the difference in weight of the battery in liquid before and after gas production, and then calculate the volume change of the battery based on Archimedes' principle, and measure the gas production based on the overall volume change of the battery. However, in fact, there is usually a certain residual space inside the battery, especially hard-shell batteries, so the volume does not change immediately in the early stages of gas production. Therefore, this method cannot provide information on gas production changes before the battery case is deformed. , In addition, this method also requires the battery to be placed in water throughout the entire process, and cannot accurately change the working temperature conditions of the battery, which limits its application range.

In addition, there is currently a device for detecting battery gas production. This device wraps a pressure sensor around a metal rod that can be welded to the battery top cover, and 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 the pressure recorder outside the casing through a connecting line to obtain real-time pressure changes inside the battery, thereby monitoring the gas production inside the battery. However, this method requires the introduction of additional metal rods to carry the pressure sensor. Since the battery operation process is accompanied by complex electrochemical reactions and will produce corrosive gases, such as HF, etc., it is easy to cause corrosion of the metal rods and affect the sensor. Reliability, additionally. The pressure sensor transmits data through the electrical connection with the pressure recorder, which will cause electromagnetic interference with the electrical connection components inside the battery itself; furthermore, the metal rod used in the device needs to use the center hole of the cylindrical core Space placement makes it impossible to generalize to square hard-shell batteries.

In order to solve the above problems, embodiments of the present application provide a hard-shell battery detection device, method and system.

The following first introduces the hard-shell battery detection device provided by the embodiment of the present application.

Referring to Figure 1, which is a schematic structural diagram of a hard-shell battery detection device provided by an embodiment of the present application. As shown in Figure 1, the hard-shell battery detection device provided by an embodiment of the present application may include: a hard-shell battery case 100 Hard case battery and air pressure sensor.

. Usually, the hard-shell battery also includes a battery core disposed inside the hard battery case 100 .

The air pressure sensor includes a transmission optical fiber 110 and a pressure-sensitive sensing chip 120 provided with a Faber cavity (hereinafter referred to as the pressure-sensitive sensing chip 120), wherein the transmission optical fiber 110 includes a first end and a second end. The pressure-sensitive sensor chip 120 is connected to the first end of the transmission optical fiber 110 and transmits optical signals through the transmission optical fiber 110 .

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.

The pressure-sensitive sensor chip 120 is a sensor chip sensitive to air pressure.

The pressure-sensitive sensor chip 120 is placed inside the hard battery case 100 .

The second end of the transmission optical fiber 110 is led out to the outside of the hard battery case 100 .

The hard-shell battery detection device provided by the embodiment of the present application includes a hard-shell battery with a hard 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 Faber cavity, wherein the transmission optical fiber Comprising a first end and a second end, the pressure-sensitive sensing chip is connected to the first end of the transmission optical fiber, and passes

The transmission optical fiber transmits the optical signal, and 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. According to the embodiment of the present application, during the operation of the battery, optical signals are transmitted to the pressure-sensitive sensor chip provided 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, causing pressure The Faber cavity in the pressure-sensitive sensing chip is deformed, which in turn causes changes in the optical signal returned inside the pressure-sensitive sensing chip. The changes in the optical signal are transmitted to the optical fiber demodulation system outside the battery through the transmission optical fiber, and are demodulated through the optical fiber. The system analyzes the optical signal to determine the corresponding air pressure signal. Based on the air pressure signal, the gas change amount inside the battery can be determined, thereby achieving in-situ detection of the gas change amount inside the battery.

In a possible implementation, the pressure-sensitive sensor chip provided with the Fabry-Perot cavity can be based on the Fabry-Perot (Fabry-Perot) interference principle and MEMS (Micro Electromechanical System). The fiber optic pressure sensing chip made with electromechanical system technology can be made of silicon-glass or Si-Si material.

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

In a possible implementation manner, the transmission optical fiber can be a communication pigtail, one end of the communication pigtail is a connector, and the other end is a fiber break. When connecting to the pressure-sensitive sensor chip, the broken end of the optical fiber 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 external equipment (such as an optical fiber demodulation device, etc.).

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

In a possible implementation, as shown in FIG. 1 , the hard battery case 100 can be formed by joining a case 101 and a case cover 102 to each other. The housing 101 and the housing cover 102 are both made of hard material, such as aluminum. The housing 101 can be provided with an upward opening, and the housing cover 102 can be placed on the upward opening of the housing 101, so that the hard battery case 100 is formed by joining the two.

The case 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 case 100 through the through hole 1021 on the case cover 102 .

The diameter of the through hole 1021 opened in the case cover 102 may be equal to or larger 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 case 100 through the through hole 1021 .

Further, in one example, as shown in FIG. 1 , 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 other structures on the cover 102 as described above.

In a possible implementation, the pressure-sensitive sensing chip is disposed inside the hard battery case, and the distance between it and the bottom of the case cover may be greater than or equal to 1 mm.

Furthermore, in order to prevent the pressure-sensitive sensing chip from being squeezed by the cells and other structures inside the hard-shell battery, there is also a certain distance between the pressure-sensitive sensing chip and other structures inside the hard-shell battery. The specific distance can be set according to actual needs.

Furthermore, in order to minimize the length of the transmission optical fiber, the pressure-sensitive sensor chip can be placed near the lower edge of the through hole.

In one possible implementation, because the diameter of the transmission fiber is small, usually between 25-250um, there is a large gap between the size of the transmission fiber and the pressure-sensitive sensor chip, so it is difficult to directly connect to the pressure-sensitive sensor chip. . Therefore, in order to facilitate the connection between the pressure-sensitive sensing chip and the transmission optical fiber, the air pressure sensor may also include a protective tube.

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

The material of the protective tube can be consistent with the transmission optical fiber, such as quartz, so that the protective tube and the transmission optical fiber can be more matched.

The protective tube may include a first end and a second end. When the first end of the transmission optical fiber is connected to the pressure-sensitive sensing chip, the first end of the transmission optical fiber may be inserted from the second end of the protective tube and removed from the protective tube. The first end of the transmission optical fiber is passed through, 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.

In order to facilitate connecting the first end of the transmission optical fiber to the pressure-sensitive sensor 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, so that the first end of the protective tube is The connection with the pressure-sensitive sensor chip realizes the connection between the first end of the transmission optical fiber and the pressure-sensitive sensor chip.

In one example, the shape of the first end of the protective tube may match the shape of the pressure-sensitive sensing chip. The shape of the pressure-sensitive sensing chip may be circular or polygonal. In this way, it is easier to connect the first end of the protection tube to the pressure-sensitive sensor chip.

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. By Experiments have determined that the above dimensions can ensure that the structure of the pressure-sensitive sensing chip matches the battery core and meet the range and sensitivity of the battery pressure test.

In one example, the first end of the protective tube and the pressure-sensitive sensor chip can be connected by adhesive bonding. For example, UV curing glue can be used for adhesive bonding. UV curing glue has the advantages of good solidification, reliable operation and portability. Low melting point glass can also be used for adhesive bonding.

In one example, in order to facilitate the insertion of the first end of the transmission optical fiber into the protective tube, the inner diameter of the protective tube may be equal to or larger than the diameter of the transmission optical fiber, so that the transmission optical fiber can be inserted into the protective tube. The diameter of the transmission fiber can be the core diameter of the transmission fiber, or the total diameter of the core and cladding.

In one example, when the transmission optical fiber is connected to the pressure-sensitive sensor chip through a protective tube, part of the transmission optical fiber will remain in the protective tube, and the distance between the part of the transmission optical fiber remaining in the protective tube and the inner wall of the protective tube can be A reliable connection between the two is achieved by sealing with glue. Among them, the sealing glue used can be epoxy resin, PET glue or UV solid glue, etc.

In one example, the height of the protective tube may be 1-50mm. It is determined through experiments that the above dimensions can meet the range and sensitivity of battery pressure testing.

Further, when the transmission optical fiber is connected to the pressure-sensitive sensor chip through the protective tube, the second end of the transmission optical fiber can be left outside the second end of the protective tube. Based on this, the second end of the protective tube can pass through the hard battery The through hole on the shell cover is led to the outside of the hard battery case. Because the second end of the transmission optical fiber is left outside the second end of the protective tube, it is ensured that the second end of the protective tube is led to the outside of the hard battery case. The second end of the transmission optical fiber is led out to the outside of the hard battery case. Correspondingly, the diameter of the through hole on the shell cover needs to be equal to or larger than the diameter of the second end of the protection tube.

After the second end of the protective tube passes through the through hole, the gap between it and the through hole can be sealed by glue. The sealing glue used can be UV curable glue, epoxy resin glue, polyacrylic acid glue, etc.

Through the technical solution of the above implementation method, by sealing the protective tube and the through hole, the sealing performance of the hard-shell battery is ensured, and the protective tube can also be prevented from moving in the through hole.

In a possible implementation, the size of the through hole on the hard battery case cover can also match the size of the pressure-sensitive sensor chip. This implementation can facilitate the pressure-sensitive sensor from the outside after the battery is formed. The chip extends into the battery, which also facilitates subsequent replacement of the pressure-sensitive sensor chip.

Based on the hard-shell battery detection device provided in the above embodiment, correspondingly, the embodiment of the present application also provides a hard-shell battery detection method, which method is applied to the hard-shell battery detection device provided in the above embodiment.

Referring to Figure 2, a schematic flow chart of a hard-shell battery detection method provided by an embodiment of the present application is shown. As shown in Figure 2, the hard-shell battery detection method provided by an embodiment of the present application may include the following steps:

S21. During the working process of the hard-shell battery, the incident light signal is transmitted to the pressure-sensitive sensor chip through the transmission optical fiber.

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

S22. Receive the reflected light signal returned by the pressure-sensitive sensor chip based on the incident light signal through the transmission optical fiber.

In one example, the pressure-sensitive sensor chip reflects the incident light signal after receiving the incident light signal, thereby obtaining a reflected reflected light signal.

S23. Analyze the reflected light signal and obtain the corresponding air pressure signal.

In one example, the transmission optical fiber can transmit the reflected light signal to the optical fiber demodulation device connected to it, and then the optical fiber demodulation device can use preset logic to analyze the reflected light signal to obtain the corresponding air pressure signal. This air pressure signal It can reflect the air pressure value inside the battery.

During the operation of the battery, when gas is generated or absorbed inside, the internal air pressure of the battery will change. Usually, when gas is generated, the air pressure will increase. When gas is absorbed, the air pressure will decrease, and changes in air pressure will cause The Faber cavity in the pressure-sensitive sensor chip installed inside the battery deforms, which in turn causes the reflected light signal reflected by the pressure-sensitive sensor chip to change. Therefore, by analyzing the reflected light signal, the corresponding air pressure signal can be determined .

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

Changes in the air pressure signal are usually related to changes in the amount of gas inside the battery. Therefore, when determining the amount of change in air pressure inside the battery based on the air pressure signal obtained in S23, you can first determine the amount of change in the air pressure signal based on the air pressure signal according to actual needs, and then The amount of gas change is determined based on the change in air pressure signal.

In one example, the correlation between the change amount of the air pressure signal and the change amount of the gas inside the battery can be determined in advance through experiments, etc., and then after the change amount of the air pressure signal is determined, the corresponding gas change can be determined based on this correlation quantity.

An embodiment of the present application provides a method for detecting a hard-shell battery. During the working process of the hard-shell battery, the transmission optical fiber is used to transmit data to a pressure-sensitive sensing chip provided with a Faber cavity inside the hard shell of the hard-shell battery. The incident light signal, when gas is generated inside the battery, will increase the internal air pressure, causing the Faber cavity in the pressure-sensitive sensing chip installed inside to deform, thereby causing the reflection of the pressure-sensitive sensing chip to return. When the light signal changes, the corresponding air pressure signal is determined by analyzing the reflected light signal returned by the pressure-sensitive sensor chip. Based on the air pressure signal, the gas change amount in the hard battery can be determined, thereby realizing the change of gas inside the hard battery. Quantitative in situ detection.

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

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

The hard-shell battery detection device 320 includes a hard-shell battery and a pressure sensor. For its specific structure, please refer to the description of the above embodiments and will not be described again here.

Among them, the battery testing device 300 can be electrically connected to the positive and negative electrodes of the hard-shell battery through electrical connection wires, and is used to set the hard-shell battery to a working state. The function of the battery testing device 300 is to put the hard-shell battery into working condition. It can use an existing mature battery charging and discharging testing device, such as a charger and discharger.

The optical fiber demodulation device 310 is connected to the second end of the transmission optical fiber 321 of the air pressure sensor, and is used to transmit the incident light signal to the pressure-sensitive sensing chip inside the hard-shell battery through the transmission optical fiber 321, and to receive the pressure-sensitive sensing through the transmission optical fiber 321. The reflected light signal returned by the chip is analyzed through the preset logic to obtain the corresponding air pressure signal, and then the gas change amount inside the hard-shell battery is determined based on the change in the air pressure signal.

In the hard-shell battery detection system provided by the embodiment of the present application, the hard-shell battery is set to the working state through the battery testing device. During the working process of the hard-shell battery, the optical fiber demodulation device transmits signals to the hard-shell battery through the transmission optical fiber. The internal pressure-sensitive sensor chip with a Faber cavity transmits the incident light signal, and receives the reflected light signal returned by the pressure-sensitive sensor chip based on the first signal through the transmission optical fiber. When gas is generated inside the battery, it will cause the internal The air pressure increases, causing the Faber cavity in the pressure-sensitive sensing chip installed inside to deform, which in turn causes the reflected light signal returned by the pressure-sensitive sensing chip to change. The optical fiber demodulation device passes the pressure-sensitive sensing The reflected light signal returned by the chip is analyzed to determine the corresponding air pressure signal. According to the change of the air pressure signal, the gas change amount in the hard battery can be determined, thereby achieving in-situ detection of the gas change amount inside the hard battery.

In a possible implementation, as shown in Figure 4, the optical fiber demodulation device may include: a light source 401, a coupler 402, a demodulation module 403 and a computer 404.

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

When the optical fiber demodulation device is applied to the hard-shell battery detection system provided in the above embodiment, the coupler 402 can be connected to the second end of the transmission fiber of the air pressure sensor in the hard-shell battery detection device, so that the light source 401 can be used The incident light signal is transmitted to the pressure-sensitive sensor chip through the transmission optical fiber, and the reflected light signal returned by the pressure-sensitive sensor chip based on the incident light signal can be transmitted to the demodulation module 403 . The demodulation module 403 has built-in preset analysis logic, and the corresponding air pressure signal can be obtained by analyzing the received reflected light signal through the preset analysis logic, and then transmits the air pressure signal to the computer 404, and the computer 404 can determine the air pressure signal based on the air pressure signal. The amount of gas change inside a hard case battery.

In one example, the computer 404 can compare and calculate the air pressure signal output by the demodulation module 403 with a previously collected or set air pressure signal according to actual needs, determine the change amount of the air pressure signal, and then determine the change amount of the air pressure signal based on the preset change amount of the air pressure signal. The correlation relationship with the gas change amount inside the battery determines the gas change amount inside the hard shell battery corresponding to the determined change amount of the air pressure signal.

For example, when it is necessary to determine the gas change amount of a hard-shell battery from the time it leaves the factory to the current detection moment, the air pressure signal output by the demodulation module 403 can be compared and calculated with the initial air pressure signal measured when the battery leaves the factory, and then the calculated air pressure can be calculated. The amount of change can determine the amount of gas change in the hard-shell battery from the factory to the current time.

For another example, when it is necessary to determine the gas change amount of the hard-shell battery from the previous detection time to the current detection time, the air pressure signal output by the demodulation module 403 can be compared and calculated with the air pressure signal measured at the previous detection time, and then based on the calculation The obtained gas pressure change amount can determine the gas change amount of the hard-shell battery from the previous detection time to the current detection time.

The analytical logic built into the demodulation module 403 is used to derive the corresponding air pressure signal based on the reflected light signal. This logic can be set based on multiple experimental results, experience or theoretical calculations. For example, it can be calibrated through multiple experiments based on the performance of different sensors. Set later.

In one example, the above logic may be to determine the deformation amount of the Faber 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 Faber cavity, and then obtain the corresponding air pressure signal, etc.

Through the technical solution of the above implementation, it is possible to use the optical fiber demodulation device to analyze the gas production inside the hard-shell battery based on the reflected light signal.

It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application, but not to limit it; 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 it can still be Modifications may be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions may be made to some of the technical features, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions in the embodiments of the present application.

Claims

A hard-shell battery detection device, including: a hard-shell battery provided with a hard battery shell and an air pressure sensor;

The air pressure sensor includes a transmission optical fiber and a pressure-sensitive sensing chip provided with a Faber cavity, wherein the transmission optical fiber includes a first end and a second end, and the pressure-sensitive sensing chip is connected to a third end of the transmission optical fiber. One end is connected and optical signals are transmitted 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.
The hard shell battery detection device according to claim 1, wherein the hard battery shell is formed by a shell and a shell cover joined to each other;

The shell 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.
The hard-shell battery testing device according to claim 2, wherein the distance between the pressure-sensitive sensing chip and the bottom of the cover is greater than or equal to 1 mm.
The hard-shell battery detection device according to claim 2, wherein the air 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.
The hard-shell battery detection device according to claim 4, wherein the material of the protective tube is the same as the material of the transmission optical fiber.
The hard-shell battery testing device according to claim 4, wherein 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 passes through the second end of the protective tube and passes out of the first end of the protective tube;

The first end of the transmission optical fiber is connected to the pressure-sensitive sensor chip through the first end of the protective tube.
The battery of claim 6, wherein the transmission optical fiber is sealed by glue between a portion within the protective tube and an inner side wall of the protective tube.
The hard-shell battery detection device according to claim 6, wherein 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.
The hard-shell battery testing device according to claim 8, wherein the second end of the protective tube and the through hole are sealed by sealing glue.
A hard-shell battery detection method, applied to the hard-shell battery detection device according to any one of claims 1 to 9, the method includes:

During the operation of the hard-shell battery, the incident light signal is transmitted to the pressure-sensitive sensing chip through the transmission optical fiber;

Receive the reflected light signal returned by the pressure-sensitive sensing chip based on the incident light signal through the transmission optical fiber;

Analyze the reflected light signal to obtain the corresponding air pressure signal;

The amount of gas change inside the hard shell battery is determined based on the air pressure signal.
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 claims 1-9;

The battery testing device is electrically connected to the positive and negative electrodes 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 used to transmit the incident light signal to the pressure-sensitive sensor chip inside the hard-shell battery through the transmission optical fiber, and receive the pressure signal through the transmission optical fiber. Based on the reflected light signal returned by the incident light signal, the sensitive sensor chip analyzes the reflected light signal through preset logic, determines the corresponding air pressure signal, and determines the gas inside the hard shell battery based on the air pressure signal. amount of change.