Lithium battery test method and device and storage medium
By conducting water immersion tests under the pressure difference environment inside and outside the lithium battery, combined with multi-dimensional parameter monitoring, the problems of the single testing environment and insufficient accuracy of lithium battery sealing performance in the existing technology have been solved, and higher accuracy sealing performance assessment and early warning have been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- EVE ENERGY CO LTD
- Filing Date
- 2026-02-12
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies for lithium battery sealing testing use a single environment with limited accuracy, making it difficult to fully reflect the sealing status of lithium batteries under complex environments.
By establishing a pressure difference environment between the inside and outside of the lithium battery, liquid is injected into the sealed test chamber, and the state of the lithium battery during the liquid injection process is monitored. By combining multi-dimensional parameter monitoring and data fusion analysis, the sealing performance of the lithium battery is determined.
It enhances the realism and diversity of the testing environment, improves testing accuracy, enables early warning of seal failure and precise location of leaks, and provides seal rating assessment.
Smart Images
Figure CN122016172A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present invention relate to the field of testing technology, and in particular to a testing method, device and storage medium for lithium batteries. Background Technology
[0002] With the widespread application of lithium batteries in electric vehicles, energy storage systems, and other fields, their safety and reliability have become a focus of attention. Leaks or poor sealing during use can lead to internal electrolyte leakage, short circuits, and even fires and explosions, posing safety hazards. Therefore, effective testing of the sealing performance of lithium batteries is crucial.
[0003] In existing technologies, pressure testing or airtightness testing is commonly used to evaluate the sealing performance of lithium batteries. However, these methods often suffer from problems such as a limited testing environment, inability to simulate actual usage conditions, and limited testing accuracy. For example, traditional pressure testing only applies a constant pressure to determine sealing performance, which is insufficient to comprehensively reflect the sealing status of lithium batteries under complex environments. Summary of the Invention
[0004] This invention provides a testing method, equipment, and storage medium for lithium batteries, which solves the technical problems of limited testing environment and limited testing accuracy in the prior art for testing the sealing performance of lithium batteries.
[0005] This invention provides a testing method for lithium batteries, the testing method comprising:
[0006] Place the target lithium battery into a sealed test chamber;
[0007] Establish an internal and external pressure difference environment for the target lithium battery, wherein the internal air pressure of the target lithium battery is lower than the external air pressure;
[0008] Maintaining the internal and external pressure difference environment, liquid is injected into the sealed test chamber;
[0009] Monitor the state of the target lithium battery during the liquid injection process;
[0010] The sealing performance of the target lithium battery was determined based on the monitoring results.
[0011] Furthermore, establishing an internal and external pressure difference environment for the target lithium battery, wherein the internal gas pressure of the target lithium battery is lower than the external gas pressure includes:
[0012] The sealed test chamber is evacuated to establish a pressure difference environment between the inside and outside of the target lithium battery, and the internal air pressure of the target lithium battery is lower than the external air pressure.
[0013] Furthermore, establishing an internal and external pressure difference environment for the target lithium battery, wherein the internal gas pressure of the target lithium battery is lower than the external gas pressure includes:
[0014] Both the sealed test chamber and the target lithium battery are evacuated to establish a pressure difference environment between the inside and outside of the target lithium battery, and the internal air pressure of the target lithium battery is lower than the external air pressure.
[0015] Furthermore, injecting liquid into the sealed test chamber includes:
[0016] Liquid is injected into the sealed test chamber based on at least one of the following dynamic scenarios:
[0017] The liquid level rises from the bottom of the target lithium battery at a set speed until the target lithium battery is completely submerged;
[0018] The liquid level is maintained at a set height of the target lithium battery and subjected to periodic fluctuations;
[0019] The target lithium battery is subjected to localized spraying or rinsing at a designated location.
[0020] Furthermore, determining the sealing performance of the target lithium battery based on monitoring results includes:
[0021] If the monitoring results are in one of the following states, the target lithium battery is determined to have failed to seal:
[0022] The insulation resistance of the target lithium battery decreases to below a safety threshold at a set rate;
[0023] The difference between the internal and external air pressure of the target lithium battery changes at a set rate;
[0024] The target lithium battery was emitting continuous bubbles.
[0025] Furthermore, after determining that the target lithium battery has failed to seal, the method further includes:
[0026] The leak point of the target lithium battery can be located based on the liquid level height at the time of seal failure or the observed bubble source.
[0027] Furthermore, after determining that the target lithium battery has failed to seal, the method further includes:
[0028] Based on the rate of change of the difference between the internal and external air pressure of the target lithium battery, and in combination with the internal cavity volume of the target lithium battery, the leakage rate of the target lithium battery is estimated.
[0029] The sealing rating of the target lithium battery is determined based on the leakage rate.
[0030] Furthermore, monitoring the state of the target lithium battery during the liquid injection process includes:
[0031] The performance parameters of the target lithium battery during the liquid injection process and the presence of bubble sources are monitored. The performance parameters include at least pressure parameters, electrical safety parameters, secondary diagnostic parameters, and physical parameters.
[0032] Furthermore, after completing the sealing test of the target lithium battery, the method further includes:
[0033] The target lithium battery was disassembled to check for water stains and corrosion inside, thus verifying the accuracy of the sealing test.
[0034] This invention also provides a testing device for lithium batteries, the device comprising:
[0035] At least one processor; and
[0036] A memory communicatively connected to the at least one processor; wherein,
[0037] The memory stores a computer program that can be executed by the at least one processor, which enables the at least one processor to perform the lithium battery testing method described in any of the above embodiments.
[0038] This invention also provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions, which are used to cause a processor to execute the lithium battery testing method described in any of the above embodiments.
[0039] This invention discloses a testing method, equipment, and storage medium for lithium batteries. The testing method includes placing a target lithium battery into a sealed test chamber; establishing an internal and external pressure difference environment for the target lithium battery, with the internal air pressure of the target lithium battery lower than the external air pressure; maintaining the internal and external pressure difference environment while injecting liquid into the sealed test chamber; monitoring the state of the target lithium battery during the liquid injection process; and determining the sealing performance of the target lithium battery based on the monitoring results. This invention, by establishing an internal and external pressure difference environment for the lithium battery and conducting a water immersion test within this environment, solves the technical problems of limited testing environment and accuracy in existing lithium battery sealing performance tests, thereby improving the realism and diversity of the testing environment and enhancing testing accuracy. Attached Figure Description
[0040] Figure 1 This is a flowchart of a lithium battery testing method provided in an embodiment of the present invention;
[0041] Figure 2 This is a schematic diagram of the structure of a lithium battery testing device provided in an embodiment of the present invention. Detailed Implementation
[0042] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.
[0043] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this invention are used to distinguish different objects, not to limit a specific order. The various embodiments of this invention described below can be performed individually or in combination with each other; the embodiments of this invention do not impose specific limitations in this regard.
[0044] Figure 1 This is a flowchart of a lithium battery testing method provided in an embodiment of the present invention.
[0045] like Figure 1 As shown, the testing method for this lithium battery specifically includes the following steps:
[0046] S101, Place the target lithium battery into the sealed test chamber.
[0047] Specifically, the lithium battery testing device includes a sealed test chamber with a dedicated through-chamber sealing interface. This interface connects the gas space inside the target lithium battery to a high-precision differential pressure sensor and a pressure regulation system, enabling independent control and monitoring of the internal pressure of the target lithium battery. It also connects the sealed test chamber to the pressure regulation system, allowing for the regulation and monitoring of the internal pressure. Furthermore, the electrical interfaces of the target lithium battery and the wiring for the temperature sensor are all routed through the through-chamber sealing interface, ensuring the airtightness of the sealed test chamber.
[0048] S102, establish the internal and external pressure difference environment of the target lithium battery, and the internal air pressure of the target lithium battery is lower than the external air pressure.
[0049] Specifically, after placing the target lithium battery into the sealed test chamber, the test chamber is closed, and the air pressure regulation system is activated to evacuate the inside of the target lithium battery and / or the entire test chamber until a preset negative pressure difference ΔP is established and maintained stably on both sides of the target lithium battery casing. This creates an internal and external pressure difference environment where the internal air pressure is lower than the external air pressure. For example, -20kPa, -50kPa, etc., simulate a pressure difference at a specific altitude or any other pressure difference environment designed as needed.
[0050] It should be noted that in the later stages of testing, normal pressure can be quickly restored or even positive pressure can be applied to simulate sudden pressure changes such as lithium batteries rapidly moving from low altitude to high altitude or submersibles rapidly surfacing, to observe whether this leads to more serious sealing failures.
[0051] S103, maintain the internal and external pressure difference environment, and inject liquid into the sealed test chamber.
[0052] Specifically, after establishing the internal and external pressure difference environment, liquid is injected into the sealed test chamber to conduct a water immersion test, and this pressure difference environment must be maintained continuously throughout the core stage of the entire water immersion test. The injected liquid can be room temperature water or a specific liquid with specific density, viscosity, and conductivity to simulate the intrusion of fluids with different properties; no specific restrictions are imposed here. The form of liquid injection can be dynamically changed as needed, such as slow water rise, fluctuating water rise, jetting / flushing, etc.
[0053] It should be noted that, in addition to the test environment combining negative pressure and immersion, it can also be combined with thermal cycling to simulate the multiple stress coupling effects of negative pressure, immersion, and alternating high and low temperatures, in order to further test the performance of lithium batteries. No specific limitations are made here.
[0054] S104 monitors the state of the target lithium battery during the liquid injection process.
[0055] Specifically, during the process of injecting liquid into the sealed test chamber where the target lithium battery is placed, various parameters of the target lithium battery are monitored in real time from multiple dimensions to obtain monitoring results.
[0056] S105, Determine the sealing performance of the target lithium battery based on monitoring results.
[0057] Specifically, after obtaining the monitoring results of the target lithium battery, data fusion analysis is performed based on the monitoring results, and the sealing failure of the target lithium battery is diagnosed, located, and the risk is quantified according to the analysis results, so as to finally determine the sealing performance of the target lithium battery.
[0058] This invention addresses the technical problems of limited testing environment and accuracy in existing lithium battery sealing tests by establishing an internal and external pressure difference environment for the lithium battery and conducting water immersion tests under this environment. It achieves the technical effects of improving the authenticity and diversity of the testing environment and enhancing testing accuracy.
[0059] In one optional implementation, S102 specifically includes:
[0060] The sealed test chamber is evacuated to establish a pressure difference environment between the inside and outside of the target lithium battery, with the internal air pressure of the target lithium battery being lower than the external air pressure.
[0061] Specifically, when establishing an internal and external pressure difference environment for the target lithium battery, the inside of the target lithium battery can be evacuated directly through the through-chamber sealing interface so that the internal air pressure of the target lithium battery is lower than the external air pressure.
[0062] In another alternative implementation, S102 further includes:
[0063] Both the sealed test chamber and the inside of the target lithium battery were evacuated to establish a pressure difference environment between the inside and outside of the target lithium battery, with the internal air pressure of the target lithium battery being lower than the external air pressure.
[0064] Specifically, in order to expand the differential pressure adjustment range, in addition to directly evacuating the inside of the target lithium battery, a vacuum can also be evacuated inside the sealed test chamber to create the required differential pressure between the inside and outside of the target lithium battery.
[0065] Optionally, S103 injecting liquid into the sealed test chamber specifically includes:
[0066] Liquid is injected into the sealed test chamber based on at least one of the following dynamic scenarios:
[0067] The liquid level rises from the bottom of the target lithium battery at a set speed until it completely submerges the target lithium battery; the liquid level is maintained at a set height of the target lithium battery and periodic fluctuations are applied; a set location on the target lithium battery is locally sprayed or flushed.
[0068] Specifically, the liquid injection method adopts a dynamic scene simulation approach. Under negative pressure, different liquid injection methods can be set, such as negative pressure slow water rise, "negative pressure half-body immersion + undulation", negative pressure local spraying / rinsing, etc.
[0069] Among them, "negative pressure slow water rise" refers to slowly raising the liquid level from the bottom of the target lithium battery (at one of the above-mentioned set speeds) until the target lithium battery is completely submerged; "negative pressure half-body immersion + fluctuation" refers to maintaining the liquid level at a specific height of the target lithium battery, such as at the interface or at the height of the explosion-proof valve, and applying periodic fluctuations to the target lithium battery; "negative pressure local spray / flushing" refers to applying directional water flow impact to suspected weak points of the target lithium battery, such as connectors or welds.
[0070] Optionally, S104 specifically includes:
[0071] Monitor the performance parameters of the target lithium battery during the liquid injection process and whether there is a source of air bubbles. The performance parameters include at least pressure parameters, electrical safety parameters, secondary diagnostic parameters, and physical parameters.
[0072] Specifically, during the state monitoring of the target lithium battery, the following key parameters need to be monitored simultaneously:
[0073] (1) Pressure parameters. These include the absolute pressure Pin inside the target lithium battery and the liquid pressure (or liquid level converted pressure) Pout inside the sealed test chamber. Specifically, the core monitoring indicator is the change curve of the real-time pressure difference ΔPreal = Pin - Pout between the two. If ΔPreal shows an abnormal increase (tending to zero), it indicates that water has entered the target lithium battery and the seal has failed.
[0074] (2) Electrical safety parameters. This includes the insulation resistance of the positive / negative terminals of the target lithium battery to the casing (ground). Under negative pressure, if water is drawn in and forms a conductive path, the insulation resistance of the target lithium battery will decrease significantly.
[0075] (3) Secondary diagnostic parameters. These include the conductivity of the water in the sealed test chamber and the composition of the gas inside the target lithium battery. Specifically, if the liquid injected into the sealed test chamber is deionized water, an increase in conductivity indicates that there is a leak in the electrolyte inside the target lithium battery; the gas inside the target lithium battery is sampled and detected through a reserved sampling port, with the main detection indicators being whether water has entered and hydrogen gas has been generated.
[0076] (4) Physical parameters. These include the internal and surface temperatures of the target lithium battery and the liquid temperature inside the sealed test chamber.
[0077] During the state monitoring of the target lithium battery, it is possible to visually observe or use camera equipment to capture whether bubbles are generated after the target lithium battery is injected with liquid, so as to determine whether there is a source of bubbles.
[0078] Based on the above technical solutions, S105 specifically includes:
[0079] If the monitoring results show one of the following conditions, the target lithium battery is determined to have failed to seal:
[0080] The insulation resistance of the target lithium battery decreases to below a safety threshold at a set rate; the difference between the internal and external air pressure of the target lithium battery changes at a set rate; and continuous bubbles emerge from the target lithium battery.
[0081] Specifically, if the monitoring results show that the insulation resistance of the target lithium battery drops sharply (i.e. at the set speed) to below the safety threshold, or the difference between the internal and external air pressure of the target lithium battery, ΔPreal, undergoes an irreversible and significant change, such as a rapid rebound, or if the naked eye / camera device observes continuous bubbles emerging from the target lithium battery, i.e., the air inside the target lithium battery is replaced and discharged by water, then the sealing of the target lithium battery is determined to be faulty.
[0082] Optionally, after determining that the target lithium battery has failed to seal, the method further includes:
[0083] Locate the leak point of the target lithium battery based on the liquid level height at the time of seal failure or the observed bubble source.
[0084] Specifically, if the sealing failure of the target lithium battery is determined, the leak point can be accurately located at the specific location of the target lithium battery, such as the bottom, side, or interface, by combining the liquid level height at the moment of sealing failure and the bubble source observed by external water flow / camera equipment. This makes it easier for testers to determine the cause of the leak as soon as possible.
[0085] Optionally, after determining that the target lithium battery has failed to seal, the method further includes:
[0086] Based on the rate of change of the difference between the internal and external air pressure of the target lithium battery, combined with the internal cavity volume of the target lithium battery, the leakage rate of the target lithium battery is estimated; the sealing level of the target lithium battery is determined based on the leakage rate.
[0087] Specifically, if the sealing failure of the target lithium battery is determined, the rate of change of the difference between the internal and external air pressure ΔPreal of the target lithium battery, combined with the volume of the internal cavity of the target lithium battery, can be used to estimate the rate of water intrusion (or air leakage), that is, to estimate the leakage rate of the target lithium battery, thereby providing a quantitative indicator for the sealing level of the target lithium battery.
[0088] Optionally, after completing the sealing test of the target lithium battery, the method further includes:
[0089] The target lithium battery was disassembled to check for water stains and corrosion inside, thus verifying the accuracy of the sealing test.
[0090] Specifically, after completing the sealing test of the target lithium battery, the sealing test chamber is opened under safety measures to conduct an internal inspection of the target lithium battery, including disassembling it to check for water stains, corrosion, and other conditions inside the target lithium battery, in order to further verify the accuracy of the monitoring results.
[0091] Simultaneously, the performance of the target lithium battery can be retested. This involves drying the target lithium battery that has not experienced thermal runaway and retesting its capacity, internal resistance, and other properties to assess the performance degradation caused by water ingress, thus providing more evidence for the performance evaluation of the target lithium battery.
[0092] In this embodiment of the invention, (1) by organically combining the two stringent conditions of "continuous negative pressure" and "dynamic immersion", the most demanding sealing challenge scenario is simulated. The test conditions far exceed the existing standards and can better expose the potential defects of the target lithium battery; (2) the ultimate test and quantitative evaluation of sealing performance are realized. By applying constant stress to the sealing system through continuous negative pressure, the "micro-leakage" defect can be exposed more quickly. By monitoring the rate of change of ΔPreal, the leakage rate of the sealing component can be quantitatively evaluated, providing accurate data support for sealing design; (3) early warning and precise location are realized. Changes in insulation resistance and differential pressure often precede visible water ingress or electrical short circuits, providing a valuable early warning window. Combined with liquid level and visual monitoring, the leakage point can be quickly and accurately located, greatly improving the efficiency of failure analysis; (4) new failure modes are revealed. This method can discover failure modes that cannot be found by normal pressure immersion test, such as good sealing under normal pressure, but failure due to material deformation under negative pressure, or premature opening of the explosion-proof valve under negative pressure. (5) the design and selection of lithium batteries are guided. The test results provide direct verification data and improvement directions for the optimization of battery pack structure design, sealing material selection, and sealing process (welding, gluing, installation torque).
[0093] Figure 2 This is a schematic diagram of a lithium battery testing device provided in an embodiment of the present invention. This lithium battery testing device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The lithium battery testing device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.
[0094] like Figure 2As shown, the lithium battery testing device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer programs stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 can also store various programs and data required for the operation of the lithium battery testing device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.
[0095] Multiple components in the lithium battery testing equipment 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, optical disk, etc.; and a communication unit 19, such as a network card, modem, wireless transceiver, etc. The communication unit 19 allows the lithium battery testing equipment 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.
[0096] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as a lithium battery testing method.
[0097] In some embodiments, the cell testing method may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded into and / or installed onto the lithium battery testing device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the cell testing method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to perform the lithium battery testing method by any other suitable means (e.g., by means of firmware).
[0098] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.
[0099] Computer programs used to implement the testing methods for lithium batteries in this invention can be written in any combination of one or more programming languages. These computer programs can be provided to the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer programs can be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.
[0100] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.
[0101] To provide user interaction, the systems and techniques described herein can be implemented on lithium battery testing equipment, which includes: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the lithium battery testing equipment. Other types of devices can also be used to provide user interaction; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).
[0102] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.
[0103] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.
[0104] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and no limitation is imposed herein.
[0105] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.
Claims
1. A testing method for lithium batteries, characterized in that, The testing method includes: Place the target lithium battery into a sealed test chamber; Establish an internal and external pressure difference environment for the target lithium battery, wherein the internal air pressure of the target lithium battery is lower than the external air pressure; Maintaining the internal and external pressure difference environment, liquid is injected into the sealed test chamber; Monitor the state of the target lithium battery during the liquid injection process; The sealing performance of the target lithium battery was determined based on the monitoring results.
2. The testing method for lithium batteries according to claim 1, characterized in that, Establishing a pressure difference environment between the inside and outside of the target lithium battery, wherein the internal gas pressure of the target lithium battery is lower than the external gas pressure, includes: The sealed test chamber is evacuated to establish a pressure difference environment between the inside and outside of the target lithium battery, and the internal air pressure of the target lithium battery is lower than the external air pressure.
3. The testing method for lithium batteries according to claim 1, characterized in that, Establishing a pressure difference environment between the inside and outside of the target lithium battery, wherein the internal gas pressure of the target lithium battery is lower than the external gas pressure, includes: Both the sealed test chamber and the target lithium battery are evacuated to establish a pressure difference environment between the inside and outside of the target lithium battery, and the internal air pressure of the target lithium battery is lower than the external air pressure.
4. The test method for lithium batteries according to any one of claims 1-3, characterized in that, Injecting liquid into the sealed test chamber includes: Liquid is injected into the sealed test chamber based on at least one of the following dynamic scenarios: The liquid level rises from the bottom of the target lithium battery at a set speed until the target lithium battery is completely submerged; The liquid level is maintained at a set height of the target lithium battery and subjected to periodic fluctuations; The target lithium battery is subjected to localized spraying or rinsing at a designated location.
5. The testing method for lithium batteries according to claim 1, characterized in that, The sealing performance of the target lithium battery was determined based on the monitoring results, including: If the monitoring results are in one of the following states, the target lithium battery is determined to have failed to seal: The insulation resistance of the target lithium battery decreases to below a safety threshold at a set rate; The difference between the internal and external air pressure of the target lithium battery changes at a set rate; The target lithium battery was emitting continuous bubbles.
6. The testing method for lithium batteries according to claim 5, characterized in that, After determining that the target lithium battery has failed to seal, the method further includes: The leak point of the target lithium battery can be located based on the liquid level height at the time of seal failure or the observed bubble source.
7. The testing method for lithium batteries according to claim 5, characterized in that, After determining that the target lithium battery has failed to seal, the method further includes: Based on the rate of change of the difference between the internal and external air pressure of the target lithium battery, and in combination with the internal cavity volume of the target lithium battery, the leakage rate of the target lithium battery is estimated. The sealing rating of the target lithium battery is determined based on the leakage rate.
8. The testing method for lithium batteries according to claim 1, characterized in that, Monitoring the state of the target lithium battery during the liquid injection process includes: The performance parameters of the target lithium battery during the liquid injection process and the presence of bubble sources are monitored. The performance parameters include at least pressure parameters, electrical safety parameters, secondary diagnostic parameters, and physical parameters.
9. The testing method for lithium batteries according to claim 1, characterized in that, After completing the sealing test of the target lithium battery, the method further includes: The target lithium battery was disassembled to check for water stains and corrosion inside, thus verifying the accuracy of the sealing test.
10. A testing device for lithium batteries, characterized in that, The device includes: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the testing method for the lithium battery according to any one of claims 1-9.
11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that, when executed by a processor, implement the testing method for the lithium battery according to any one of claims 1-9.