A system for performing acoustic measurements of batteries

Abstract

Aspects of the present disclosure relate to a test fixture and non-destructive acoustic inspection method for scanning and inspecting batteries and determining and characterizing various physical phenomena in those batteries. In one aspect, a rastering system for non-invasive acoustic inspection of battery cells includes a holder for placing a battery in the system for acoustic inspection, at least one transducer configured to perform acoustic measurements on the battery cells, and a controller configured with inspection parameters for performing the acoustic measurements, the inspection parameters being dynamic and permutable depending on at least one or more of the shape, size, and form factor of the battery cells.

Description

Technical Field

[0001] This application claims the benefit of priority under 35 U.S.C. 119(e) to U.S. Provisional Patent Application No. 63 / 309,987, filed on February 14, 2022, entitled "SYSTEMS AND METHODS FOR COLLECTING ACOUSTIC DATA ON BATTERY CELLS TO DETECT DEFECTS", and claims the benefit of priority to U.S. Patent Application No. 18 / 109,482, filed on February 14, 2023, entitled "SYSTEMS AND METHODS FOR COLLECTING ACOUSTIC DATA ON BATTERY CELLS TO DETECT DEFECTS", the contents of which are hereby incorporated by reference in their entirety for all purposes.

[0002] This invention was made with government support under Grant No. SBIR1831080 awarded by the National Science Foundation. The United States government has certain rights in this invention.

[0003] The disclosed aspects relate to acoustic inspection of batteries, and more particularly, to a set of test devices and non-destructive acoustic inspection methods for scanning and inspecting batteries to determine and characterize various physical phenomena in these batteries.

Background Art

[0004] For example, increased use across various industries such as home appliances, automobiles, and clean energy is driving the demand for battery cell production. Efficient and rapid battery diagnostic methods are crucial for improving battery quality, lifespan, and manufacturing process efficiency. In manufacturing and production, cost reduction (e.g., price per kilowatt-hour (kWh)) is a key objective. Production costs and quality can be reduced through the optimization of existing processes and / or the introduction of new technologies. For example, technological advancements in improved monitoring, manufacturing, and diagnostics can lead to cost efficiencies through reduced production process time (and consequently reduced energy consumption during production), reduced waste from damaged cells and cell components, and improved quality.

[0005] Batteries are supplied in a variety of sizes and shapes, and there are numerous subsets of variables and factors that can affect the accuracy of the data obtained for battery testing. [Brief explanation of the drawing]

[0006] The accompanying drawings are provided to aid in illustrating various aspects of this disclosure and are provided for illustrative purposes only, not as an limitation.

[0007] [Figure 1] This disclosure provides an exemplary system for analyzing a sample using acoustic signal-based analysis, relating to several aspects of this disclosure. [Figure 2] This invention provides an alternative exemplary system for analyzing a sample using acoustic signal-based analysis, relating to several aspects of this disclosure. [Figure 3] This invention illustrates an exemplary rastering system for acoustic testing of rectangular battery cells according to several aspects of this disclosure. [Figure 4] This invention illustrates another exemplary rastering system for acoustic testing of rectangular battery cells, relating to several aspects of this disclosure. [Figure 5] This disclosure illustrates an exemplary rastering system for acoustic testing of cylindrical battery cells, relating to several aspects of this disclosure. [Figure 6] An example of the system shown in Figure 5 in operation for inspecting cylindrical battery cells, according to some aspects of this disclosure, is presented. [Figure 7] Another example of the system of Figure 5 for inspecting cylindrical battery cells, relating to some aspects of this disclosure, is shown. [Figure 8] This document illustrates an exemplary system architecture for enabling the operation of the exemplary rastering system shown in Figures 3-7, relating to several aspects of this disclosure. [Figure 9] This document illustrates an exemplary process for operating a rastering system for acoustic testing of battery cells, relating to several aspects of this disclosure. [Figure 10] This document illustrates an exemplary computing device architecture for an exemplary computing device relating to several aspects of this disclosure. [Overview of the project]

[0008] Aspects of this disclosure relate to a set of test equipment and non-destructive acoustic testing methods for scanning and inspecting batteries and determining and characterizing various physical phenomena in these batteries.

[0009] In one embodiment, a rastering system for non-invasive acoustic inspection of a battery cell includes a holder for positioning the battery cell within the system for acoustic inspection, at least one transducer configured to perform acoustic measurements on the battery cell, and a controller comprising inspection parameters for performing the acoustic measurements, the inspection parameters being dynamically replaceable depending on at least one or more of the shape, size, and shape factors of the battery cell.

[0010] In another embodiment, the rastering system is configured for the inspection of cylindrical battery cells, and the battery cells are cylindrical battery cells.

[0011] In another embodiment, at least one transducer is configured to move vertically along the curved surface of the battery cell at each rotation angle to transmit and receive acoustic signals through the battery cell.

[0012] In another embodiment, at least one transducer is configured to acquire a plurality of acoustic measurements along the axial surface of the battery cell at each rotation angle based on the received acoustic signal.

[0013] In another embodiment, the controller is configured to analyze each of several acoustic measurements to extract acoustic features that represent the physical characteristics of the battery cell at each rotation angle, and to generate an aggregated map based on the acoustic features extracted at each rotation angle.

[0014] In another embodiment, the rastering system further includes one or more rollers configured to rotate the battery cell at a predetermined rotation angle until the entire curved surface of the battery cell is acoustically measured.

[0015] In another embodiment, at least one transducer is an array of transducers packaged in a cylindrical unit to transmit and receive acoustic signals through the axial surface of a battery cell at each predetermined rotation angle.

[0016] In another embodiment, at least one transducer is a roller transducer.

[0017] In another embodiment, after each rotation of the battery cell by one or more rollers, at least one transducer is configured to acquire acoustic measurements along the axial surface of the battery cell to obtain a plurality of acoustic measurements.

[0018] In another aspect, the controller is configured to analyze each of a plurality of acoustic measurements to extract an acoustic feature indicative of a physical characteristic of a battery cell at a corresponding rotation angle, and generate an aggregation map based on the acoustic features extracted at each rotation angle.

[0019] In another aspect, the controller is configured to output at least one of an analysis result of a plurality of acoustic measurements and an aggregation map.

[0020] In another aspect, the rastering system is configured for inspecting rectangular battery cells, and the battery cells are rectangular battery cells.

[0021] In another aspect, at least one transducer is configured to perform one or more of single-sided measurements and double-sided measurements of a battery cell.

[0022] In another aspect, at least one transducer is a roller transducer.

[0023] In another aspect, the battery cell is a planar cell.

[0024] In another aspect, the controller is configured to control the movement of at least one transducer in at least one of two directions to perform a plurality of individual acoustic measurements across the entire surface of the battery cell.

[0025] In another aspect, the controller is configured to analyze a plurality of individual acoustic measurements to extract significant acoustic features indicative of the physical characteristics of the battery cell.

[0026] In another aspect, the controller is configured to generate an aggregation map of a plurality of acoustic measurements.

[0027] In another aspect, the controller is configured to output at least one of the aggregation map and an analysis result of a plurality of acoustic measurements.

[0028] In another embodiment, the inspection parameter specifies a set of ultrasonic tests from among those that can be applied to perform acoustic measurements.

[0029] In another aspect, multiple ultrasonic testing includes pulse / echo, pitch catch & through transmission, and beam steering & phase array application.

[0030] In one embodiment, a non-invasive method of battery inspection using acoustic measurement comprises transmitting an acoustic signal through a battery cell via one or more first transducers, receiving a response signal in response to the acoustic signal in one or more second transducers, and processing the acoustic response signal to extract acoustic features that indicate the physical properties of the battery cell, wherein the controller consists of inspection parameters for performing the acoustic measurement, and the inspection parameters are dynamically and interchangeable depending on at least one or more of the shape, size, and shape factors of the battery cell. [Modes for carrying out the invention]

[0031] Specific aspects and embodiments of this disclosure are provided in the following description and related drawings. Alternative embodiments may be devised without departing from the scope of this disclosure. Furthermore, well-known elements of this disclosure are not described in detail or are omitted so as not to obscure the relevant details of this disclosure.

[0032] The term “typical” is used herein to mean “serving as an example, illustration, or representation.” Any embodiment described herein as “typical” is not necessarily construed to be preferable or advantageous to other embodiments. Similarly, the term “embodiments of the present invention” does not require that all embodiments of the present invention include the described features, advantages, or modes of operation.

[0033] The terms used herein are intended solely to describe specific aspects and are not intended to limit the aspects of the disclosure. Where used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context explicitly indicates otherwise. Furthermore, where used herein, the terms “equip,” “equip,” “contain,” and / or “contain” indicate the presence of a described feature, integer, step, action, element, and / or component, but are understood not to exclude the presence or addition of one or more other features, integers, steps, actions, elements, components, and / or groups thereof.

[0034] Furthermore, numerous embodiments are described in terms of a series of operations performed, for example, by elements of a computing device. It is recognized that the various operations described herein may be performed by a specific circuit (e.g., an application-specific integrated circuit (ASIC)), by program instructions executed by one or more processors, or a combination of both. It can also be considered that these series of operations described herein are embodied in any form of computer-readable storage medium that stores a corresponding set of computer instructions, which, when executed, cause the relevant processors to perform the functions described herein. Thus, the various operations of the present invention may be embodied in numerous different forms, all of which are considered to be within the scope of the claimed subject matter. Furthermore, for each of the embodiments described herein, any corresponding form of such embodiment may be described herein, for example, as “logic configured to perform the described operations.”

[0035] For example, increased use across various industries such as home appliances, automobiles, and clean energy is driving the demand for battery cell production. A non-limited application for battery cells is the electric vehicle (EV) industry. According to various market studies, this industry will require massive growth (approximately 15 times current capacity) to meet EV demand by 2030. The cost of battery cell production should decrease by about 40%, according to some estimates. Furthermore, evidence highlights the importance of EV battery reliability, given the enormous human and financial losses incurred from EV recalls due to faulty batteries (over $3 billion in 2020-2021).

[0036] The battery manufacturing process is not without its challenges. For example, raw material costs are rising, and problems during manufacturing can result in low-quality battery cells. These unreliable battery cells may then be incorporated into various applications, such as electric vehicles (EVs), ultimately leading to the costly malfunctions mentioned above.

[0037] For example, battery defects can result in insufficient battery cell performance or catastrophic battery (and / or device) failure. Such defects can occur during the manufacturing process or during normal battery operation after the battery has been placed in a device. These defects are generally located deep within the battery cell and are difficult to detect because they are either invisible to non-invasive imaging methods or not substantial enough to be detected by electrical testing methods until the defect causes substantial damage / degradation to the battery.

[0038] In some cases, manufacturing defects may include, but are not limited to, creases, wrinkles, or holes in conventional polymer-based separator materials, cracks or fractures in solid ceramic-based separators, dry spots in cells due to insufficient electrolyte saturation, holes, creases, or delamination of electrodes, misalignment of layers, foreign matter fragments, burrs, metal particle inclusions, lacerations, creases, and tab defects including poor quality welding, misalignment of electrodes, holes and creases in electrodes, and delamination of electrode materials.

[0039] Operational defects may include, but are not limited to, plating of lithium metal in the anode material (e.g., dendritic growth), dry spots within the cell due to electrolyte degradation, and gas generation due to electrolyte or other chemical decomposition. All of these defects can cause microshorts within the battery, which, if propagated, can lead to premature cell failure, rapid capacity loss, and / or catastrophic failure.

[0040] Currently available methods for investigating defective batteries include X-ray or CT scans of the cells, and dismantling the battery after it has been flagged for low performance, safety hazard, or field failure.

[0041] In the field of ultrasound testing, there is a broad application space and a large subset of important input variables that affect the fidelity of ultrasonic measurements. Some of these variables include the contact method, transducer frequency and bandwidth, and acoustic testing method (through, pitch catch, pulse echo). When ultrasound is considered in relation to battery testing, another subset of physical phenomena exists, including the cell's geometric shape, shape factors (pouch, prismatic, cylindrical), chemical composition, and process state, requiring unique optimization of acoustic testing parameters to adequately capture and quantify these phenomena.

[0042] When performing ultrasound-based testing of batteries, the broad parameter space for test equipment and sample shape factors can present challenges involving non-routine engineering and design tasks. For example, a subset of ultrasound test settings may be optimized to visualize folded separators within lithium-ion battery pouch cells, but may not be able to detect electrode inclusions within the same cell. Conversely, observing separator folds may require different ultrasound settings for prismatic / hard can cells and pouch cells. The broad parameter space in ultrasound when it comes to battery testing may necessitate that test systems be designed to accommodate different transducer types, allow for different test methods to be performed electronically, and / or that the test bed accommodates most common battery shape factors.

[0043] Ultrasonic testing is also significantly influenced by external factors. Even in the most basic tests, results can vary considerably due to mechanical alignment, contact force, external temperature, pressure, and environmental fluctuations, as well as variations within the ultrasonic coupling used to transmit ultrasonic pulses from the transducer to the test sample. The robustly designed ultrasonic testing systems described herein can overcome all of these challenges to obtain accurate and reproducible results.

[0044] The systems and techniques for detecting defects in batteries described herein can address the above-mentioned problems (and other problems). Specifically, this disclosure relates to a set of test equipment (raster scanning systems) and non-destructive acoustic testing methods for scanning and inspecting batteries and determining and characterizing various physical phenomena in these batteries. The raster scanning systems disclosed herein are suitable for acoustic testing of battery cells of different shapes and forms (e.g., rectangular battery cells, cylindrical battery cells) and can perform acoustic measurements on one side and / or both sides of such battery cells.

[0045] This raster scanning system enables battery manufacturers to configure acoustic tests using a variety of acoustic methods, including but not limited to through-transmission, pitch-catch, or pulse-echo, to swap between different ultrasonic transducers, perform field-versus-operand measurements, and adjust test settings to be appropriately optimized for the application of interest. Once the ultrasonic test setting is established, the motion system allows discretized ultrasonic testing to be safely and repeatedly performed across the entire spatial domain of the battery at a resolution and coupling method selected by the user. The resulting test data is then extracted and processed by a data analysis pipeline, including but not limited to proprietary data analysis techniques developed by Liminal Insights, Inc. of Emeryville, California, to process and extract significant acoustic features that indicate the current and / or future physical characteristics of the battery, including the techniques described in U.S. Patent No. 17 / 112,756 filed December 4, 2020, which is incorporated herein by reference in its entirety.

[0046] A description of a typical system for performing non-invasive acoustic measurements of battery cells is provided with reference to Figures 1 and 2. Next, with reference to Figures 3–7, the disclosure provides exemplary embodiments of techniques for detecting, identifying, and / or locating defects in batteries both during and after manufacturing. Next, with reference to Figures 8 and 9A–B, the disclosure provides exemplary embodiments of battery defect simulations used in models for detecting and identifying defects. The disclosure concludes with a description of exemplary device and system architectures with reference to Figure 10.

[0047] Figure 1 shows an exemplary system for analyzing a sample using acoustic signal-based analysis, relating to several aspects of the present disclosure. System 100 may include a sample 102. Sample 102 may include a battery cell or its components at any stage of production or manufacture of the battery cell or its individual components. In some examples, sample 102 may include a battery cell, an electrolyte at various stages of wetting / distribution through the battery cell, one or more electrodes of the battery cell, a thin film, a separator, a coating sheet, a current collector, an electrode slurry, or materials for forming any of the above components at any stage of their manufacture. System 100 may include a transmitting transducer Tx104 or other means for transmitting an excitation sound signal into the battery cell (e.g., for transmitting one or more pulses, vibrations, resonance measurements, etc., of ultrasound or other acoustic waves through the battery cell). System 100 may further include a receiving transducer Rx106 or other means for receiving / sensing the sound signal, which can receive a response signal generated from the signal transmitted by the Tx transducer 104. Any known or future-developed transducer for transmitting and receiving acoustic signals may be used as the Tx transducer 104. The signal transmitted by the Tx transducer 104 from one side of sample 102 on which the Tx transducer 104 is located may include an input excitation signal. For example, the reflected signal from the other side of sample 102 may include an echo signal. It is understood that reference to the response signal may include both the input excitation signal and the echo signal. Furthermore, the Tx transducer 104 may be configured to receive a response signal, and similarly, the Rx transducer 106 may be configured to transmit an acoustic signal. Any known or future-developed transducer for transmitting and receiving acoustic signals may be used as the Rx transducer 106. Thus, even though they are shown separately as Tx and Rx, the function of these transducers may be for both transmitting and receiving acoustic signals.In various alternative examples, even if not specifically illustrated, one or more Tx transducers and one or more Rx transducers may be arranged on the same side or wall of Sample 102, or on different (e.g., opposing) sides. Throughout this disclosure, transducer pairs (transmitting transducers and receiving transducers) may be referred to. Transducer Tx104 and transducer Rx106 may form a transducer pair.

[0048] The acoustic pulser / receiver 108 may be coupled to Tx and Rx transducers 104, 106 to control the transmission of an acoustic signal (e.g., an ultrasonic signal) and to receive a response signal. The acoustic pulser / receiver 108 may include a controller 108-1 for adjusting the amplitude, frequency, and / or other signal characteristics of the transmitted signal. The acoustic pulser / receiver 108 may also receive a signal from the Rx transducer 106. In some examples, the acoustic pulser / receiver 108 may be configured as a coupled unit, but in some examples, the acoustic pulser for transmitting an excitation signal via the Tx transducer 104 may be a separate unit that communicates with the receiver for receiving a signal from the Rx transducer 106. The processor 110 communicating with the acoustic pulser / receiver 108 may be configured to store and analyze the response signal waveform in accordance with this disclosure. Although illustrated as a single processor, the processor 110 may include one or more processors, including remote processors, cloud computing infrastructure, etc.

[0049] Although not explicitly shown in Figure 1, multiple Tx transducers and / or multiple Rx transducers may be positioned at one or more spatial locations across sample 102. This makes it possible to investigate spatial variations in acoustic signal features across sample 102. The multiplexer may be configured to communicate with an acoustic pulser / receiver 108 to separate and channel the transmitted excitation signal and the received response signal. In some examples, various acoustic couplers (e.g., solid, liquid, or a combination thereof), such as couplers 103 and 105, may be used to make or improve contact between the Tx and Rx transducers 104, 106 and sample 102. Furthermore, various mounting or fixing mechanisms (e.g., pneumatic, compression, screw, spring, etc.) may be used to establish or improve contact between the Tx and Rx transducers 104, 106 and sample 102.

[0050] Figure 2 shows another exemplary system for analyzing a sample using acoustic signal-based analysis, relating to some aspects of the present disclosure. Compared to Figure 1, the system 200 in Figure 2 shows a system in which multiple pairs of transmit and receive transducers are used to transmit signals through a sample under test (e.g., a battery cell) and to perform acoustic signal-based analysis of the sample.

[0051] System 200 includes several transmit Tx transducers 202 (each of which may be the same as Tx transducer 104 in Figure 1). Figure 2 shows, but is not limited to, four exemplary arrays of Tx transducers 202. Any number of transducers (for example, any number of Tx transducers in the range of 1 to 10, 15, 20, etc.) may be used.

[0052] Similarly, the system 200 includes a plurality of receiving (sensing) Rx transducers 204 (each of which may be the same as the Rx transducer 106 in Figure 1). Figure 2 shows an array of four exemplary Rx transducers 204, but the disclosure is not limited to four. Any number of transducers (for example, any number of Rx transducers in the range of 1 to 10, 15, 20, etc.) may be used. Any given Tx transducer 202 and Rx transducer 204 may form a transducer pair (Figure 2 shows four transducer pairs). Figure 2 also shows a multiplexer 206 coupled to an array of four Tx transducers 202 and a multiplexer 208 coupled to an array of four Rx transducers 204. As described above, each of the multiplexers 206 and 208 may be configured to communicate with the acoustic pulser / receiver 108 to separate and channel the transmitted excitation signal and the received response signal, respectively. In some examples, various acoustic couplers (e.g., solid, liquid, or a combination thereof), such as couplers 203 and 205, may be used to make or improve contact between the Tx and Rx transducers 202, 204 and the sample 102. Furthermore, various mounting or fixing mechanisms (e.g., pneumatic, compression, screw, etc.) may be used to establish or improve contact between the Tx and Rx transducers 202, 204 and the sample 102.

[0053] The spacing between the Tx transducer 202 and the Rx transducer 204 may be uniform and the same. The system 200 also includes additional elements such as, for example, the sample 102, the ultrasonic pulser / receiver 108 (controller 108-1), and the processor 110, each of which may be the same as the corresponding relative part described above with reference to Figure 1, and are therefore not described in detail for the sake of brevity.

[0054] Exemplary systems 100 and 200 may have any shape or form, may be standalone systems, portable or fixed, etc.

[0055] Using exemplary systems used for acoustic signal analysis of batteries as described with reference to Figures 1 and 2, this disclosure now moves on to describing various rastering systems that utilize the functions and components of systems 100 and 200 to address acoustic inspection of battery cells of various shapes and sizes.

[0056] Figure 3 shows an exemplary rastering system for acoustic inspection of rectangular battery cells according to some aspects of the present disclosure.

[0057] The exemplary structure 300 in Figure 3 is an image of system 302 in real time operation for acoustically measuring the physical characteristics of an exemplary rectangular battery cell 304. Similar to systems 100 and 200 in Figures 1 and 2, system 302 may include one or more transducers, such as transducer 306 mounted on a mechanical or electric actuator attached to, for example, an x ​​and / or y and / or z moving stage. Transducer 306 may be controlled to transmit acoustic signals through multiple locations on the battery cell 304. Although not shown in exemplary structure 300, an equivalent receiving transducer may be present on the bottom of the battery cell 304 to receive a response signal in response to the acoustic signal transmitted through transducer 306.

[0058] In Example 300, either system 302 and / or alternatively, a platform on which the battery cell 304 is mounted, allows transducer 306 to move horizontally in the x and / or y directions to scan and measure multiple locations across the battery cell 304. This movement is shown in Example 308, and after each instance of measurement, the pair of transducers 306 and 310 “scan” and measure the entire surface of the battery 304 by moving a predetermined distance in the x and / or y directions and making measurements (individual / independent measurements) across the battery cell 304.

[0059] An exemplary flow 312 illustrates this process, in which, after each measurement by the receiver transducer 310, the transmitter transducer 306 / system 302 generates an acoustic waveform, which can be processed by various signal processing methods to generate an acoustic metric 314 or a number of acoustic metrics for that particular measurement. The system 302 (and / or alternatively, the battery cell 304) then moves a predetermined distance (e.g., 1 mm, 2 mm, etc.) in the x and / or y directions to repeat the measurement at a different location and generate similar acoustic metrics 314 at the new location. Once the scanning of the battery cell 304 is complete, all acoustic metrics corresponding to different measurement locations can be aggregated into an acoustic map (metric map) of the entire battery cell 304, such as map 316. The individual acoustic metrics 314 and / or aggregated map 316 can be further processed / analyzed to extract significant features or scores that indicate the physical characteristics of the battery cell 304. Such physical characteristics may include, but are not limited to, health status, charge stage, and various scores indicating the current and / or future physical condition and performance of the battery cell 304. Such scores may include, but are not limited to, a wetness score, solid electrolyte interphase (SEI) formation score, aging score, cycle life prediction score, detection, labeling, and location of defects within the battery cell 304. Various numerical and signal processing techniques may be employed to extract and interpret significant acoustic features indicating the physical characteristics of the battery cell 304, utilizing trained machine learning models. Non-limiting examples of such techniques include the techniques described in U.S. Patent Application No. 17 / 112,756, filed December 4, 2020, which is incorporated herein by reference in its entirety, and have been developed by Liminal Insights, Inc. of Emeryville, California.

[0060] Figure 4 shows another exemplary rastering system for acoustic inspection of rectangular battery cells according to some aspects of the present disclosure.

[0061] Example 400 in Figure 4 shows three snapshots A, B, and C of the system. Each snapshot is of an exemplary system at a different location when scanning the battery cell 404. The battery cell 404 may be a rectangular / planar cell.

[0062] The transducer 402 may be a roller transducer fixed to the housing / arm 401, may be made of any known or hereafter developed material, and may be equipped with mechanical and / or electrical systems and actuators to enable the arm 401 to move the transducer 404 over the battery cell 404 to perform acoustic measurements.

[0063] In snapshot A, transducer 402 is shown positioned above battery cell 404, ready to begin scanning the battery cell 404. In snapshot B, transducer 402 is in contact with battery cell 404, rolling over the entire battery cell 404 to perform acoustic measurements. In snapshot C, transducer 402 shows that one sweep / scan of battery cell 404 is completed at the end (the other edge of battery cell 404). In this example in Figure 4, transducer 402 is performing a one-sided scan of battery cell 404. In other words, roller transducer 402 may function as both a transmitter and receiver of the acoustic signal of battery cell 404, which can then be processed and analyzed to extract significant acoustic features as described above.

[0064] Similar to the example in Figure 3, either the arm 401 / transducer 402 or the battery cell 404 may be moved in the x and / or y directions to allow the roller transducer 402 to scan the entire surface of the battery cell 404. The arm 402 may also move up and down in the z direction to bring the transducer 402 into contact with the battery cell under inspection, and after the sweep / scan is complete, the transducer 402 may be moved away from the battery cell 404.

[0065] In some examples, ultrasonic measurements performed by transmit / receive transducers such as the 104 / 106, 202 / 204, 306 / 310, and 402 transducers shown in Figures 1-4 include, but are not limited to, pulse / echo, pitch catch & through transmit, and beam steering & phase array applications. Measurements may be air-coupled, liquid-coupled, and / or solid-contact solutions, which can be tuned to balance signal-to-noise ratio (SNR) and various test environment trade-offs. Measurements may be performed according to various delay line and beam focusing strategies to detect defects smaller than 100 μm in battery cells.

[0066] Furthermore, transducers 104 / 106, 202 / 204, 306 / 310, and 402 in Figures 1-4 can be bundled into 1D, 2D, and / or 3D arrays that can be controlled via common and / or individualized operating systems (see Figure 8, described later) to measure batteries statically or dynamically in real-time high-throughput scenarios.

[0067] The bifacial acting system(s) may be designed to bring a single transducer, transducer array, and other ultrasonic sensors close to the battery cell under inspection to an appropriate focal distance when non-contact inspection is performed, or alternatively, the sensor head(s) may be designed to make full physical contact with the battery cell under inspection. The acting system(s) and its dynamics may be fully tunable and controllable via one or more controllers, as described later with reference to Figure 8. Variable azimuthal resolution may be automatically selected and implemented depending on whether the defect / phenomenon of interest is a large bulk defect or a localized defect embedded within a battery cell, such as sample 102 / 202, battery cell 304 / 404. Sample 102 may be a battery cell similar to battery cells 304 and 404.

[0068] Variable azimuth resolution can be automatically selected and implemented depending on whether the defect / phenomenon of interest is a large bulk defect or a localized defect embedded deep within the battery cell.

[0069] The exemplary systems shown in Figures 1-4, particularly the rastering systems in Figures 3 and 4, can be designed so that the battery cells to be inspected are automatically inserted for inspection and then removed, allowing such systems to be fully integrated into battery manufacturing lines for high-speed, non-invasive inspection of battery cell components such as electrodes and separators, battery cells, battery modules, and battery packs.

[0070] Furthermore, the exemplary systems in Figures 1-4, particularly the rastering systems in Figures 3 and 4, can utilize an automated rotating carousel architecture to switch between different types of transducers (e.g., transducers 306 / 310 and roller transducer 402) without the need to manually change transducers for different types of battery cells being inspected.

[0071] Figure 5 shows an exemplary rastering system for acoustic testing of cylindrical battery cells according to some aspects of the present disclosure.

[0072] An exemplary system 500 for inspecting cylindrical battery cells may include a casing 502 made of any known or hereafter developed material. A glass top 504 may cover part of the system 500 and include an opening 506 for receiving the cylindrical battery cell to be acoustically inspected. A holding mechanism 508 may be used to hold and / or rotate the cylindrical battery cell to be inspected. This test is described further later with reference to Figures 6 and 7. The system 300 may also include a stage 510 for mounting and attaching transducers for multiple methods of inspecting cylindrical acoustic cells, which is described further later. Figure 5 further shows an exemplary z-translation motor 512. The motor 512 is configured to allow full rotation of the cylindrical battery cell for acoustic inspection with infinite resolution. For example, the motor 512 can control the movement of multiple idlers to rotate the cylindrical battery cell.

[0073] Figure 6 shows an example of the system of Figure 5 in operation for inspecting cylindrical battery cells according to some aspects of the present disclosure.

[0074] Example 600 includes two snapshots A and B of the operation of system 500 in Figure 5.

[0075] In snapshot A, the cylindrical cell 602 is shown positioned within a holder in the system 500 (for example, through the opening 506 in Figure 5). Two exemplary rollers 604 and 605 (which may also be called idlers or grippers) are shown, connected to actuators (mechanical arms) 608A and 608B, respectively. In one example, actuators 608A and 608B may be controlled / operated by a motor 512. Snapshot A also shows two roller (cylindrical) transducers 606 and 607, each controlled / driven by actuators 608C and 608D, respectively. Each of transducers 606 and 607 may have a wired controller to a controller (for example, processor 110 in Figure 1) via cables 610 and 611. Cable 611 is shown in snapshot B. Each of the transducers 606 and 607 may be an array of transducers packaged in a cylindrical unit to perform a single instance of transmitting and receiving an acoustic signal at any rotation angle. In this case, at any given angle, the entire vertical or axial slice of the battery cell 602 (from top to bottom of the battery cell 602) can be acoustically measured in that single instance of transmitting and receiving an acoustic signal.

[0076] In snapshot A, rollers 604 and 605 and transducers 606 and 607 are separated from the cylindrical cell 602, which indicates either that the battery cell 602 has just been placed in the system 500 for inspection, or that the inspection of the battery cell 602 is complete and it can be removed from the system 500.

[0077] In snapshot B, rollers 604 and 605 and transducers 606 and 607 are in contact with the cylindrical cell 602. While in contact, rollers 604 and 605 can rotate the cylindrical cell 602 in the theta direction (as indicated by 612). With each incremental rotation in the theta direction 612, transducers 606 and 607 perform an acoustic inspection of the cylindrical cell 602 by transmitting and receiving acoustic signals. After each rotational measurement to measure some or all theta positions from 0° to 360°, the battery cell 602 may be translated (moved) by some incremental distance in the axial (theta) direction or z direction. The rotation of the cylindrical cell 602 in the theta direction 612 continues until the entire axial surface of the cylindrical cell 602 is acoustically scanned.

[0078] Figure 7 shows another example of the system of Figure 5 for inspecting cylindrical battery cells, according to some aspects of the present disclosure.

[0079] Figure 700 shows an example of a rastering system in operation for acoustic inspection of a cylindrical battery cell. Compared to the example in Figure 6, the cylindrical cell 702 may be mounted in a mechanism that controls the rotation of the cylindrical cell 702 in the theta direction 612 via the bottom surface of the cylindrical cell 702, rather than being held in a fixed position and rotated using rollers. The cylindrical cell 702 may be rotated in the theta direction 612 by a predetermined rotation angle. For example, the cylindrical cell 702 may be rotated 5 degrees at a time, and with each rotation, it may be acoustically scanned using transducers 704 and 706. Transducers 704 and 706 may be controlled to move up and down in the z direction to scan the cylindrical cell 702 at a given angle to perform multiple individual and independent measurements (e.g., slices of the cylindrical cell 702) over the curved surface (axial length) of the cylindrical cell 702. This process continues until the entire axial surface (curved surface) of the cylindrical cell 702 is acoustically scanned.

[0080] Schematic Figure 710 shows a simplified version of the process for rotating and inspecting the cylindrical cell 702.

[0081] The figure also shows the stepwise construction of an aggregated map of acoustic measurements of the cylindrical cell 702. As described above, at each rotation angle, transducers 704 and 706 may move up and down to transmit and receive acoustic signals through a strip at the vertical position of the cylindrical cell 702. The results of these acoustic measurements are recorded as shown in the figure. For example, result 720 shows the acoustic measurement 722 at a position along the vertical surface of the cylindrical cell 702 at angle 0. The cylindrical cell 702 may then be rotated by 5 degrees to obtain another set of acoustic measurement 724, which may be added to measurement 722 to produce map 726. This process may continue until the cylindrical cell 702 is rotated 360 degrees, acoustically measured, and an aggregated map 728 is generated. The results shown in map 728 may be processed and analyzed as described above to extract significant acoustic features that indicate the physical properties of the battery cell 702.

[0082] The non-limiting examples described above utilize a combination of rotational propulsion and alignment mechanisms, as described above, to simultaneously fix and rotate cylindrical cells of any size or length around an axis. Such systems can be adapted to, for example, the 18650, 2170, and 4680 cylindrical cell shape factors, as well as any other existing and / or future-developed shape factors, sizes, and / or shapes relating to cylindrical battery cells.

[0083] In these exemplary systems, a transducer, transducer pair, transducer array, or other type of ultrasonic sensor is moved adjacent to this mechanism along its longitudinal axis as the propulsion system moves in the theta direction, and then measurements can be taken at a selected point relative to a linear cross-section of a battery cell, such as a cylindrical cell 702. The result is a fully disassembled ultrasonic scan of the cylindrical battery, which can be visualized in 2D space as described above with reference to Figure 7.

[0084] In some examples, the exemplary systems described above, with reference to Figures 5-7, are designed so that cylindrical samples can be safely and effectively inserted and removed from the system after testing, without the need for manual engagement with the rotational propulsion and alignment system at the throughput required for battery production.

[0085] Figure 8 shows an exemplary system architecture for enabling the operation of the exemplary rastering system examples shown in Figures 3-7, according to some aspects of this disclosure.

[0086] The exemplary architecture 800 relates to a rastering system for inspecting rectangular battery cells (as described with reference to Figures 3 and 4), but may be equally applicable to a rastering system for inspecting cylindrical battery cells.

[0087] As shown in the figure, the rectangular battery cell 802 may be placed within a rastering system having architecture 800. Acoustic measurements may be performed using transducers 804 (transmitting transducer) and 806 (receiving / receiver transducer). Transducers 804 and 806 may be a single transducer, multiple transducers, or a linear or matrix array of transducers. Couplers 805 and 808 may be the same as couplers 103 / 105 and 203 / 205 described with reference to Figures 1 and 2.

[0088] Architecture 800 may also include actuators 810 and 811 for controlling the movement of transducers 804 and 806, respectively. Actuators 810 and 811 may be controlled independently or collectively by, for example, a controller 812. Controller 812 may receive commands from a programmable logic controller (PLC) 814 to control actuators 810 and 811. PLC 814 may be programmed for testing battery cells in a given manufacturing environment with an emphasis on commonality to accommodate all transducers of different sizes, frequencies, bandwidths, etc., with minimal non-recurring engineering (NRE) costs. For example, PLC 814 may be programmed to control the operation of actuators 810 and 811 by controlling the operation of controller 812 to move transducers 804 and 806 by a predetermined distance relative to a battery cell 802 being acoustically measured. PLC 814 may further be programmed to control systems 816 and 818 to move the battery cell 802 in the x and / or y directions. The moving systems 816 and 818 may alternatively be controlled by the controller 812.

[0089] The PLC814 may be programmed via EASI / PC820, which may interface with a pulse generator 822 to transmit acoustic signals 824 (e.g., pulses, pitch, etc.) to a transmitter transducer 804. The EASI / PC820 may also interface with an oscilloscope 826 to control the reception of response signals 828 via a receiver transducer 806.

[0090] Figure 9 shows an exemplary process for operating a rastering system for acoustic testing of battery cells, according to some aspects of the present disclosure. The process in Figure 9 is described in terms of a controller. The controller may be the PLC 814 in Figure 8, the controller 812 in Figure 8, or the processor 110 in Figures 1 and 2. It should be noted that such a controller may have computer-readable instructions (stored in the controller or associated memory) that are executed to perform the steps in Figure 9.

[0091] In step 900, the controller may receive test parameters. These test parameters may include, but are not limited to, specifications for controlling the transmitter and receiver transducers 804 and 806, specifications for the movement of the battery cell 802 being tested (e.g., incremental movement in the x and / or y directions), and the type of acoustic measurement to be performed (e.g., pulse / echo, pitch catch and through transmission, etc.).

[0092] The specifications may optionally include parameters regarding the frequency of automatically placing and removing battery cells from the rastering system for inspection, and specifications regarding modifications to the ultrasonic tests used.

[0093] The inspection parameters may be dynamic and replaceable in the sense that one or more of the inspection parameters may be changed to correspond to the shape, size, and / or shape factors of the battery cell being inspected, depending on the shape, size, and / or shape factors of such a particular battery cell.

[0094] In step 902, the controller may perform an acoustic test of the battery cell based on the received test parameters.

[0095] In step 904, the controller may generate a visual representation of the acoustic measurements taken in step 902. Examples of such measurements may be map 316 in Figure 3, map 728 in Figure 7, and so on.

[0096] In step 906, the controller may, based on the analysis of the acoustic measurements performed as described above, extract significant acoustic features that indicate the physical characteristics of the battery cell, battery pack, and / or battery module under test.

[0097] In step 908, the controller may output the results of the analysis in step 906. As described above, the output may be one or more of the following: a wetness score, an SEI formation score, an age-related score, a cycle life prediction score, or the detection / labeling / location of defects within the battery cell. Various numerical and signal processing techniques may be used to extract and interpret significant acoustic features that indicate the physical properties of the battery cell 304, utilizing trained machine learning models. A non-limiting example of such techniques is the technique developed by Liminal Insights, Inc. of Emeryville, California, which is described in U.S. Patent Application No. 17 / 112,756 filed on 4 December 2020, the entirety of which is incorporated herein by reference.

[0098] In another example, the output may include, in addition to the results of the analysis performed in step 906, an aggregated map of acoustic measurements (e.g., map 316 or 728).

[0099] Figure 10 shows an exemplary computing device architecture for an exemplary computing device relating to several aspects of the present disclosure. The exemplary computing device architecture 1000, which can be used as various components (e.g., processor 110) of system 100 or 200, implements various technologies described herein. The components of the computing device architecture 1000 are shown communicating with each other using connections 1005, such as a bus. The exemplary computing device architecture 1000 includes a processing unit (CPU or processor) 1010 and a computing device connection 1005 that connects various computing device components to the processor 1010, including computing device memory 1015 such as read-only memory (ROM) 1020 and random access memory (RAM) 1025.

[0100] The computing device architecture 1000 may include a cache of high-speed memory directly connected to the processor 1010, connected in close proximity to the processor 1010, or integrated as part of the processor 1010. The computing device architecture 1000 may copy data from memory 1015 and / or storage device 1030 to cache 1012 for rapid access by the processor 1010. In this way, the cache can provide a performance boost to avoid delays while the processor 1010 is waiting for data. These modules and other modules may control, or be configured to control, the processor 1010 to perform various operations. Other computing device memories 1015 may also be available. Memory 1015 may include multiple different types of memory with different performance characteristics. The processor 1010 may include any general-purpose processor and hardware or software services stored in storage device 1030 and configured to control the processor 1010 and dedicated processors with software instructions incorporated into the processor design. Processor 1010 may be a self-contained system including multiple cores or processors, buses, memory, controllers, caches, etc. A multicore processor may be symmetrical or asymmetrical.

[0101] To enable interaction between the user and the computing device architecture 1000, the input device 1045 may represent any number of input mechanisms, such as a microphone for voice, a touch-sensitive screen for gesture or graphic input, a keyboard, a mouse, motion input, or voice. The output device 1035 may also be one or more of a number of output mechanisms known to those skilled in the art, such as a display, projector, television, or speaker device. In some examples, a multimodal computing device may allow the user to provide multiple types of inputs to communicate with the computing device architecture 1000. The communication interface 1040 may generally control and manage user inputs and computing device outputs. Since operation is not limited to any particular hardware configuration, the basic features described herein can be easily replaced with improved hardware or firmware configurations as development progresses.

[0102] The storage device 1030 is a non-volatile memory and may be a hard disk or other type of computer-readable medium capable of storing computer-accessible data, such as a magnetic cassette, flash memory card, solid-state memory device, digital versatile disk, cartridge, random access memory (RAM) 1025, read-only memory (ROM) 1020, and hybrids thereof. The storage device 1030 may include software, code, firmware, etc., for controlling the processor 1010. Other hardware or software modules are possible. The storage device 1030 may be connected to the computing device connection 1005. In one embodiment, a hardware module that performs a particular function may include software components stored on a computer-readable medium in relation to hardware components necessary to perform the function, such as the processor 1010, the connection 1005, and the output device 1035.

[0103] The term “computer-readable media” includes, but is not limited to, portable or non-portable storage devices, optical storage devices, and various other media capable of storing, containing, or transporting instructions and / or data. Computer-readable media may include non-temporary media on which data may be stored, and may not include carrier waves and / or temporary electronic signals that propagate wirelessly or via wired connections. Examples of non-temporary media may include, but are not limited to, magnetic disks or tapes, optical storage media such as compact discs (CDs) and digital versatile discs (DVDs), flash memory, memory, or memory devices. Computer-readable media may store code and / or machine-executable instructions that may represent procedures, functions, subprograms, programs, routines, subroutines, modules, software packages, classes, or any combination of instructions, data structures, or program statements. Code segments may be coupled to other code segments or hardware circuits by passing and / or receiving information, data, arguments, parameters, or memory content. Information, arguments, parameters, data, etc., may be passed, transferred, or transmitted via any appropriate means, including memory sharing, message passing, token passing, and network transmission.

[0104] In some embodiments, computer-readable storage devices, media, and memory may include cables or wireless signals, such as bitstreams. However, non-temporary computer-readable storage media, where mentioned, explicitly exclude media such as energy, carrier signals, electromagnetic waves, and the signals themselves.

[0105] Certain details are provided in the above description in order to provide a complete understanding of the embodiments and examples provided herein. However, it will be understood by those skilled in the art that embodiments can be carried out without these specific details. For the sake of clarity of description, in some examples the art may be presented as including individual functional blocks comprising devices, device components, steps or routines in a method embodied in software, or combinations of hardware and software. Additional components other than those shown in the figures and / or described herein may be used. For example, circuits, systems, networks, processes, and other components may be shown as components in block diagram form in order to avoid obscuring embodiments with unnecessary details. In other examples, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary details in order to avoid obscuring embodiments.

[0106] Individual embodiments may be described above as processes or methods represented as flowcharts, flow diagrams, data flow diagrams, structural diagrams, or block diagrams. While flowcharts can describe operations as a continuous process, many operations may occur in parallel or simultaneously. The order of operations may also be rearranged. A process terminates when the operations are complete, but may have additional steps not shown in the diagram. A process may correspond to a method, function, procedure, subroutine, subprogram, etc. If a process corresponds to a function, its termination may correspond to the function returning to a calling function or main function.

[0107] The processes and methods relating to the examples described above may be implemented using computer-executable instructions stored on or otherwise available from computer-readable media. Such instructions may include, for example, instructions and data that cause a general-purpose computer, a dedicated computer, or a processing device to perform a particular function or group of functions, or otherwise configure a general-purpose computer, a dedicated computer, or a processing device in that manner. Some of the computer resources used may be accessible via a network. Computer-executable instructions may include, for example, binaries, intermediate format instructions such as assembly language, firmware, and source code. Examples of computer-readable media that may be used to store the instructions, information used, and / or information generated in the methods relating to the examples described include magnetic or optical disks, flash memory, USB devices with non-volatile memory, and networked storage devices.

[0108] Devices implementing the processes and methods relating to these disclosures may include hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof, and may take any of a variety of form factors. If implemented in software, firmware, middleware, or microcode, the program code or code segment (e.g., a computer program product) for performing the required tasks may be stored in a computer-readable or machine-readable medium. A processor(s) may perform the required tasks. Typical examples of form factors include laptops, smartphones, mobile phones, tablet devices, or other small form factor personal computers, personal digital assistants, rack-mount devices, and standalone devices. The functions described herein may be embodied in peripherals or add-in cards. Such functions may, as a further example, be implemented on a circuit board across different chips or different processes running on a single device.

[0109] Instructions, a medium for carrying such instructions, computing resources for executing them, and other structures for supporting such computing resources are exemplary means for providing the functionality described herein.

[0110] In the above description, aspects of this application are described with reference to specific embodiments, but those skilled in the art will recognize that this application is not limited thereto. Therefore, although exemplary embodiments of this application are described in detail herein, it should be understood that the concept of the invention can be embodied and utilized in various other ways, and that the appended claims are intended to be interpreted as including such modifications, unless limited by the prior art. The various features and aspects of this application described above may be used individually or in conjunction. Furthermore, embodiments may be used in any number of environments and applications other than those described herein without departing from the broad spirit and scope of this specification. Therefore, this specification and the drawings should be considered illustrative, not restrictive. For illustrative purposes, the methods have been described in a particular order. In alternative embodiments, it should be recognized that the methods may be performed in a different order than described.

[0111] Those skilled in the art will understand that the less than ("<") and greater than (">") symbols or terms used herein may be replaced with less than or equal to ("≦") and greater than or equal to ("≧") symbols, respectively, without departing from the scope of this specification.

[0112] When components are described as being "configured" to perform a particular operation, such configuration can be achieved, for example, by designing an electronic circuit or other hardware to perform the operation, by programming a programmable electronic circuit (e.g., a microprocessor, or other suitable electronic circuit) to perform the operation, or by any combination thereof.

[0113] The expression "combined" refers to any component that is physically connected, directly or indirectly, to another component, and / or any component that communicates directly or indirectly with another component (for example, connected to another component via a wired or wireless connection and / or other appropriate communication interface).

[0114] While the above disclosure illustrates exemplary aspects of the invention, it should be noted that various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims. The functions, steps, and / or operations of the method claims relating to the aspects of the invention described herein do not need to be performed in any particular order. Furthermore, while elements of the invention may be described or claimed in the singular, plural forms are also considered unless explicitly stated to be limited to the singular.

[0115] Claim language or other wording that includes “at least one” and / or “one or more” of a set indicates that one member or multiple members of a set (any combination) satisfy the claim. For example, claim language that includes “at least one of A and B” or “at least one of A or B” means A, B, or A and B. In another example, claim language that includes “at least one of A, B, and C” or “at least one of A, B, or C” means A, B, C, or A and B, or A and C, or B and C, or A and B and C. The phrases “at least one” and / or “one or more” of a set do not limit the set to those listed in the set. For example, claim language that includes “at least one of A and B” or “at least one of A or B” may mean A, B, or A and B, and may further include items not listed in the set of A and B. The invention described in the original claims of this application is listed below. [1] A rastering system for non-invasive acoustic testing of battery cells, A holder for arranging battery cells within the system for the aforementioned acoustic testing, The battery cell comprises at least one transducer configured to perform acoustic measurements, A controller comprising test parameters for performing the aforementioned acoustic measurement, wherein the test parameters are dynamically replaceable depending on at least one or more of the shape, size, and shape factors of the battery cell. A rasterization system equipped with the following features. [2] The rastering system described in [1] is configured for inspecting cylindrical battery cells, wherein the battery cells are cylindrical battery cells. [3] The rastering system according to [2], wherein at least one transducer is configured to move vertically along the curved surface of the battery cell at each rotation angle to transmit and receive acoustic signals through the battery cell. [4] The rastering system according to [3], wherein at least one transducer is configured to acquire a plurality of acoustic measurements along the axial surface of the battery cell at each rotation angle based on the received acoustic signal. [5] The aforementioned controller, To extract acoustic characteristics that represent the physical properties of the battery cell at each rotation angle, each of the multiple acoustic measurements is analyzed. An aggregate map is generated based on the acoustic features extracted at each rotation angle. The rastering system described in [4] is configured as follows. [6] One or more rollers configured to rotate the battery cell at a predetermined rotation angle until the entire curved surface of the battery cell is acoustically measured. The rasterization system described in [2] further comprises the following: [7] The rastering system according to [6], wherein the at least one transducer is an array of transducers packaged in a cylindrical unit for transmitting and receiving acoustic signals through the axial surface of the battery cell at each predetermined rotation angle. [8] The rastering system according to [6], wherein after each rotation of the battery cell by the one or more rollers, the at least one transducer is configured to acquire an acoustic measurement along the axial surface of the battery cell to obtain a plurality of acoustic measurements. [9] The aforementioned controller, Each of the multiple acoustic measurements is analyzed in order to extract acoustic features that indicate the physical characteristics of the battery cell at the corresponding rotation angle. An aggregate map is generated based on the acoustic features extracted at each rotation angle. The rastering system described in [8] is configured as follows:

[10] The rasterization system according to [9], wherein the controller is configured to output at least one of the analysis results of the plurality of acoustic measurements and the aggregate map.

[11] The rastering system described in [1] is configured for inspecting rectangular battery cells, wherein the battery cells are rectangular battery cells.

[12] The rastering system according to

[10] , wherein the at least one transducer is configured to perform one or more single-sided and double-sided measurements of the battery cell.

[13] The rastering system according to

[12] , wherein at least one transducer is a roller transducer.

[14] The rastering system according to

[11] , wherein the battery cell is a planar cell.

[15] The rastering system according to

[11] , wherein the controller is configured to control the movement of the at least one transducer in at least one of two directions in order to perform a plurality of individual acoustic measurements across the entire surface of the battery cell.

[16] The rastering system according to

[15] , wherein the controller is configured to analyze a plurality of individual acoustic measurements in order to extract significant acoustic features that indicate the physical characteristics of the battery cell.

[17] The rasterization system according to

[16] , wherein the controller is configured to generate an aggregate map of the plurality of acoustic measurements.

[18] The rastering system according to

[17] , wherein the controller is configured to output at least one of the aggregate map and the analysis results of the plurality of acoustic measurements.

[19] The rastering system according to [1], wherein the inspection parameters specify a plurality of ultrasonic tests from among the ultrasonic tests that can be applied to perform the acoustic measurement.

[20] The aforementioned multiple ultrasonic tests include pulse / echo, pitch catch & through transmission, and beam steering & phase array applications, as described in

[19] .

Claims

1. A rastering system for non-invasive acoustic testing of battery cells, A holder for arranging battery cells within the system for the aforementioned acoustic testing, The battery cell comprises at least one transducer configured to perform acoustic measurements, Controller and Equipped with, The aforementioned controller, Receiving inspection parameters for performing the aforementioned acoustic measurement, wherein the inspection parameters correspond to at least one or more of the shape, size, and shape factors of the battery cell, respectively. Controlling the holder and the at least one transducer to perform the acoustic measurement based on the inspection parameters, The acoustic measurements are analyzed in order to extract acoustic characteristics that indicate the physical properties of the battery cell, Based on the extracted physical characteristics, an aggregated map of the acoustic measurements is generated. A rasterization system equipped with the following features.

2. The rastering system according to claim 1, wherein the rastering system is configured for inspecting cylindrical battery cells, and the battery cells are cylindrical battery cells.

3. The rastering system according to claim 2, wherein the at least one transducer is configured to move vertically along the curved surface of the battery cell at each rotation angle of the battery cell in order to transmit and receive acoustic signals through the battery cell.

4. The rastering system according to claim 3, wherein the at least one transducer is configured to acquire the acoustic measurement along the axial surface of the battery cell at each rotation angle of the battery cell based on the received acoustic signal.

5. The controller analyzes the acoustic characteristics and generates the aggregated map for each rotation angle of the battery cell. The rastering system according to claim 4, configured as described above.

6. One or more rollers are configured to rotate the battery cell at a predetermined rotation angle until the entire curved surface of the battery cell is acoustically measured. The rasterization system according to claim 2, further comprising the above.

7. The rastering system according to claim 6, wherein the at least one transducer is an array of transducers packaged in a cylindrical unit for transmitting and receiving acoustic signals through the axial surface of the battery cell at each predetermined rotation angle.

8. The rastering system according to claim 6, wherein after each rotation of the battery cell by the one or more rollers, the at least one transducer is configured to acquire an acoustic measurement along the axial surface of the battery cell and to obtain the acoustic measurement.

9. The rastering system according to claim 1, wherein the controller is configured to output at least one of the analysis results of the acoustic measurement values ​​and the aggregated map.

10. The rastering system according to claim 1, wherein the rastering system is configured for inspecting rectangular battery cells, and the battery cells are rectangular battery cells.

11. The rastering system according to claim 9, wherein the at least one transducer is configured to perform one or more single-sided and double-sided measurements of the battery cell.

12. The rastering system according to claim 11, wherein at least one transducer is a roller transducer.

13. The rastering system according to claim 10, wherein the battery cell is a planar cell.

14. The rastering system according to claim 10, wherein the controller is configured to control the movement of the at least one transducer in at least one of two directions in order to perform a plurality of individual acoustic measurements across the entire curved surface of the battery cell.

15. The rastering system according to claim 14, wherein the controller is configured to output at least one of the aggregation map and the analysis results of the plurality of acoustic measurements.

16. The rastering system according to claim 1, wherein the inspection parameter specifies a plurality of ultrasonic tests from among ultrasonic tests that can be applied to perform the acoustic measurement.

17. The rastering system according to claim 16, wherein the plurality of ultrasonic tests include pulse / echo, pitch catch & through transmission, or beam steering & phase array application.

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