Improvement of battery manufacturing processes based on acoustic and process signal analysis

Abstract

To provide a method, apparatus and non-transitory computer-readable storage medium for controlling a process for manufacturing an energy storage device.SOLUTION: In a method of controlling a process, signal-based analysis that can include audio signal analysis can be performed during a first process step of an energy storage device manufacturing process. Based on the signal-based analysis, at least one adjustment can be determined for a second process step of the battery manufacturing process. Information associated with the at least one adjustment can be provided to the second process step. A controller performs the at least one adjustment determined for the second process step.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The disclosed aspects are directed to improving and controlling a battery manufacturing process based on acoustic signals and / or process signals based on monitoring of various process steps. More specifically, aspects of the present technology are directed to process improvement and process control based on feedback and / or feedforward of analysis based on acoustic signals and / or process signals obtained during one or more process steps involved in the manufacture of battery cells.

Background Art

[0002] Due to the increasing demand for battery cells from various industries such as consumer electronics, automobiles, and clean energy, the production demand for battery cells is on the rise. In order to improve the quality, lifespan, and manufacturing process efficiency of batteries, an efficient and fast battery diagnosis method is important. In the case of manufacturing and production, cost reduction (for example, the price per kilowatt-hour (kWh)) is an important goal. Production costs can be reduced by optimizing existing processes and / or introducing new technologies. For example, technological advancements in the field of improved monitoring and diagnosis can improve cost efficiency by both shortening the production process time (and thereby reducing the energy consumption during production) and reducing waste due to damaged cells and cell components.

[0003] However, when battery cell components and cells are processed on a large scale through various stages of cell manufacturing, a fast, non-destructive, and inexpensive monitoring method for monitoring them is needed. Without effective monitoring during the manufacturing process, there is a possibility of low yield, low quality, and inefficient resource utilization.

Summary of the Invention

[0004] A simplified summary of one or more aspects disclosed in this specification is presented below. Accordingly, the following summary should not be considered an extensive overview of all intended aspects, nor should it be regarded as identifying key or essential elements of all intended aspects or as delimiting the scope associated with any particular aspect. Thus, the following summary is intended only to present in a simplified form certain concepts related to one or more aspects associated with the mechanisms disclosed herein, prior to the detailed description that follows.

[0005] Systems, methods, and computer-readable media for controlling a battery manufacturing process are provided. According to at least one exemplary aspect, a method for controlling a battery manufacturing process is provided. The method includes performing signal-based analysis during a first process step, determining at least one adjustment to a second process step based on the signal-based analysis performed during the first process step, where the first process step and the second process step correspond to the battery manufacturing process, and providing information related to the at least one adjustment to the second process step.

[0006] According to at least one exemplary aspect, an apparatus for controlling a battery manufacturing process is provided. In some aspects, the apparatus may include a memory storing computer-readable instructions and one or more processors, the one or more processors configured to perform signal-based analysis during a first process step, determine at least one adjustment to a second process step based on the signal-based analysis performed during the first process step, where the first process step and the second process step correspond to the battery manufacturing process, and provide information related to the at least one adjustment to the second process step.

[0007] According to at least one exemplary embodiment, a computer-readable medium for controlling a battery manufacturing process is provided. In some aspects, when executed by one or more processors, the non-transitory computer-readable medium causes the one or more processors to perform signal-based analysis during a first process step and, based on the signal-based analysis performed during the first process step, determine at least one adjustment to a second process step, where the first process step and the second process step correspond to a battery manufacturing process, and may include instructions to cause the second process step to be provided with information related to the at least one adjustment.

[0008] Other objects and advantages related to the aspects disclosed herein will become apparent to those skilled in the art based on the accompanying drawings and the detailed description.

Brief Description of the Drawings

[0009] The accompanying drawings are presented to assist in the description of various aspects of the present disclosure and are provided by way of illustration only and not for limitation.

[0010]

Figure 1

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Modes for Carrying Out the Invention

[0011] Aspects of the present technology are disclosed in the following description and the associated drawings. Alternative aspects may be devised without departing from the scope of the present disclosure. Also, well-known elements of the present disclosure are not described in detail or are omitted in order not to obscure details related to the present disclosure.

[0012] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. Similarly, the phrase "aspects of the present disclosure" does not require that all aspects of the technology include the discussed feature, advantage, or mode of operation.

[0013] The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of aspects of the present disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. Further, as used herein, the terms "comprises," "comprising," "includes," and / or "including" specify the presence of the stated feature, integer, step, operation, element, and / or component, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0014] Furthermore, many aspects are described from the perspective of a sequence of operations performed, for example, by elements of a computing device. It is recognized that the various operations described herein can be performed by a particular circuit (e.g., an application specific integrated circuit (ASIC)), by program instructions being executed by one or more processors, or by a combination of both. Also, the sequence of operations described herein can be considered to be embodied in their entirety in any form of computer-readable storage medium storing a corresponding set of computer instructions that cause the associated processor(s) to perform the functions described herein when executed. Accordingly, the various aspects of the present disclosure may be embodied in many different forms, all of which are considered to be within the scope of the claimed subject matter. Also, with respect to each of the aspects described herein, a corresponding form of any such aspect can be described herein, for example, as "logic configured to" perform the described operations.

[0015] Systems, apparatus, processes (also referred to as methods), and computer-readable media (collectively referred to as "systems and techniques") are disclosed for improving one or more process steps in the manufacture / production of an electrochemical energy storage device (e.g., a battery, a battery cell, and / or any component thereof). In some examples, the systems and techniques can be implemented by monitoring one or more steps in a manufacturing process for a battery cell using acoustic signals and / or process signals to provide feedback and / or feedforward data that can be used to modify, adjust, or otherwise implement one or more steps in the manufacturing process.

[0016] FIG. 1 shows an example system 100 for analyzing a sample 102 using acoustic signal and / or process signal-based analysis according to aspects of the present disclosure. In some examples, the sample 102 may include a battery cell or a component thereof at any stage of the production or manufacture of a battery cell or component. For example, the 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, and / or any material associated with its manufacture. Examples of production stages and related components are described in more detail with reference to FIG. 2.

[0017] In some aspects, the system 100 may include a transmission transducer Tx104 or any other component suitable for transmitting an excitation acoustic signal to the sample 102 (e.g., for transmitting one or more pulses of ultrasonic or other acoustic waves, vibrations, resonance measurements through a battery cell). In some examples, the system 100 may include a receiving transducer Rx106 or other component suitable for receiving and / or sensing a signal (e.g., an acoustic signal, a reflected signal, a transmitted signal, and / or any other signal related to the signal transmitted by the Tx transducer 104).

[0018] In some embodiments, the signal transmitted by the Tx transducer 104 (e.g., from the side on which the Tx transducer 104 of the sample 102 is located) may include an input excitation signal. In some cases, the reflected signal (e.g., from the other side of the sample 102) may include an echo signal. As used herein, the response signal may include the input excitation signal (e.g., the signal transmitted by the Tx transducer 104) and / or any reflected signal, echo signal, audio signal, etc. In some examples, the Tx transducer 104 may also be configured to receive the response signal. Similarly, the Rx transducer 106 may be configured to transmit acoustic and / or other types of excitation signals. Although FIG. 1 shows separate components as Tx and Rx, those skilled in the art will recognize that each component may perform either or both of the Tx and Rx functions. In some embodiments, one or more Tx transducers (e.g., the Tx transducer 104) and / or one or more Rx transducers (e.g., the Rx transducer 106) may be disposed on the same side or wall of the sample 102, or on different (e.g., opposing) sides of the sample 102.

[0019] In some examples, an 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 receive a response signal. The acoustic pulser / receiver 108 may include a controller (not shown) for adjusting signal parameters such as, for example, the amplitude, frequency, and / or other signal characteristics of the transmitted signal. In some cases, the acoustic pulser / receiver 108 may receive a signal from the Rx transducer 106. In some examples, the acoustic pulser / receiver 108 may be configured as a composite unit, but in some examples, the acoustic pulser for transmitting an excitation signal via the Tx transducer 104 may be an individual unit that communicates with a receiver for receiving a signal from the Rx transducer 106. In some configurations, a processor 110 that communicates with the acoustic pulser / receiver 108 may be configured to store and analyze the response signal waveform in accordance with aspects of the present technology. The processor 110 is shown as a single processor, but may include one or more processors including, for example, a remote processor, a cloud computing infrastructure, and the like.

[0020] As described above, FIG. 1 shows a configuration including a single Tx transducer 104 and a single Rx transducer 106. In some embodiments, one or more Tx transducers and / or Rx transducers may be arranged at one or more spatial positions with respect to the sample 102. In some examples, using multiple transducers at different positions may be used to determine the spatial variation of the acoustic signal characteristics across the sample 102. In some embodiments, a multiplexer (not shown) may be configured to communicate with the acoustic pulser / receiver 108 to separate and channelize the transmitted excitation signal and the received response signal. In some examples, various acoustic couplants (e.g., solids, liquids, or combinations thereof) may be used to effect or enhance contact between the Tx and Rx transducers 104, 106 and the sample 102. In some cases, various attachment or fixation mechanisms (e.g., pneumatic, compression, screws, etc.) may be used to establish or enhance contact between the Tx and Rx transducers 104, 106 and the sample 102.

[0021] In some embodiments, the system shown in FIG. 1 can be used to analyze and / or process one or more signals associated with the production of sample 102 to determine one or more parameters or data related to a manufacturing process (e.g., of a battery cell). In some examples, the data may include data related to functional quality test results from tests performed anywhere during the manufacturing process (e.g., formation capacity, self-discharge voltage drop, etc.). In further examples, the data may include process inspection data (e.g., weight of electrolyte injected during a filling process, beta gauge data from an electrode inspection). In further examples, the data may include material and / or component specifications and / or quality control data from upstream suppliers or vendors. In further examples, the data may include environmental data (e.g., temperature, humidity, etc.). In further examples, the data may include data streams generated by other process equipment (e.g., calendaring pressure, dry cell weight, electrode thickness measurements, etc.). In one typical example, during electrolyte wetting (discussed with respect to FIG. 2), the parameters and / or manufacturing process data used by system 100 may include the mass or volume of electrolyte added, the calendaring pressure (at the beginning of the process), the number or intensity of vacuum steps during immersion, information about the cell composition, information about raw materials from the supplier, environmental factors such as temperature, pressure, and humidity, inspection results from previous process steps, and custom / optional data provided by the customer / user.

[0022] Figure 2 shows an example of a production or manufacturing process 200 of one or more battery cells. As shown, process 200 includes stages or process steps 202-232. In some examples, process steps 202-232 may be performed in sequence (e.g., production of battery cells may proceed in ascending order of process steps 202-232). In other examples, one or more of process steps 202-232 included in process 200 may be excluded or performed in a different order. As used herein, feedback data may include information from a later process step used in a previous process step. Similarly, reference to feedforward data may include information from a previous process step used in a later process step.

[0023] In various aspects of the present disclosure, information collected based on acoustic signal and / or process signal-based analysis in one process step (e.g., performed using an arrangement such as system 100) may be used in one or more other process steps using any suitable combination of feedback and / or feedforward of the acoustic signal and / or process signal-based analysis. In some examples, feedback data and / or feedforward data may be used to improve the overall quality of battery cells produced using manufacturing process 200, the efficiency / cost of manufacturing process 200, the yield improvement / waste reduction of battery cells produced using manufacturing process 200, and / or the efficiency, function, or performance of one or more of process steps 202-232.

[0024] Referring to FIG. 2, manufacturing process 200 may begin with process step 202 for mixing an electrode slurry. In some examples of manufacturing a battery (e.g., a lithium-ion battery), an active electrode material, such as an active anode or cathode electrode material, is mixed with a binder and a conductive material in a solvent to form a slurry, which is then coated or applied to a web or sheet-like metal current collector sheet. When this is baked and dried, an electrode for use in the battery results. In some embodiments, uniformly coating the slurry onto the metal current collector can significantly affect the proper functioning and lifespan of the battery. Since the slurry is highly viscous and contains a large amount of solid particles and liquid components of various densities, obtaining a uniformly mixed slurry for coating consistency can be a complex and difficult process. As a result, the electrode coating can exhibit significant compositional differences along the entire current collector web. By detecting the compositional differences and manufacturing batteries having a more uniform distribution of electrode coatings accordingly, improvements in battery performance and lifespan can be achieved. Thus, the present technology can improve the overall quality of one or more subsequent process steps, as well as the final battery using the electrodes formed from the slurry, by improving process step 202 for mixing the slurry.

[0025] Process step 204 includes the coating and drying steps referred to with respect to step 202 described above. For example, when the slurry is coated on a metal sheet or current collector, it is dried. Drying may include a drying oven in which the coating material is dried based on heating. Coating of the slurry on the metal sheet can be used to form thin sheet-like components for use in electrodes, separators, exterior packages, or other battery components. In order to minimize the impact on battery safety and performance, it is important to ensure the high quality of these thin sheet-like components in terms of avoiding non-uniformities, damage, contamination, foreign matter inclusion, peeling of the coating from the substrate, or inappropriate / easily leaky packages in the coating process. In battery production, monitoring and early capture of these quality problems in-line is desirable to reduce the scrap rate, whereby the production cost of the battery (e.g., lithium-ion battery) can be significantly reduced. The systems and techniques disclosed herein (e.g., acoustic analysis) can be fed back to the preceding mixing step 202 and the ongoing coating and drying process step 204, and / or fed forward to implement corrective measures to compensate for electrode problems in subsequent steps of cell and component manufacturing, in order to prevent and / or minimize quality problems in the manufacturing process.

[0026] Process step 206 includes slitting, and the coated sheet or film can be slit or diced to appropriate dimensions. For example, in some instances, a wide electrode sheet can be coated with slurry and then sliced or slit into narrow-width strips. The slitting process can also introduce non-uniformities or irregularities, and quality can be improved by monitoring these to identify any defects.

[0027] Process step 208 includes calendaring, and the coated sheet is compressed to obtain electrodes of a desired thickness, bulk density, and porosity. Battery production can be improved by monitoring that the calendaring process step is properly performed. For example, wet and dry, calendared and / or uncalendered electrode coatings can have inconsistencies in, for example, porosity, local density, mass loading, particle aggregation, and particle size distribution, such as defects like voids, streaks, scratches, or cracks, foreign matter inclusions such as bubbles and contaminant particles (metallic and / or non-metallic), delamination or peeling of the electrode coating, peeling between the electrode coating and the metal current collector, and subsurface variations in porosity or density. It is desirable to detect and / or correct such defects early, although one or more of these defects may not be detectable via conventional optical and other inspection methods. Acoustic signal and / or process signal-based analysis can be used to identify one or more defects in process step 208, and such information can be used to improve one or more other process steps upstream and / or downstream in cell manufacturing in addition to removing or reducing defects in this process step. Conventional process data signals (such as optical or electrical measurements) may be included with the measured acoustic signals to enhance the fidelity of defect detection and can further strengthen the information provided to upstream and / or downstream process steps.

[0028] Process step 210 may include vacuum drying that can be performed on the calendared sheet. Vacuum drying can be added to the heat drying described with reference to process step 204. In some examples, this step 210 may occur after step 204 or 208. The drying temperature, duration of the vacuum, and vacuum pressure greatly affect the amount of moisture or solvent remaining in the electrode and, as a result, can affect the quality of the cell.

[0029] Process step 212 may include electrode forming, and the strips of the electrode sheet obtained by slitting in process step 206 (during calendaring and vacuum drying) can be cut or diced into units of a specific shape (such as a square or rectangular shape with tabs) for use in the battery. Accurate electrode forming is important for both jelly roll type cells and cut and stack type cells. Improperly cut electrodes can result in misalignment of the electrodes in the composite generation step 214. The forming or slitting of the electrodes can also generate burrs and metal particles that may be embedded in the electrode stack.

[0030] Process step 214 may include composite generation, and two or more formed electrode units can be joined or mixed. This is a process step for assembling the anode, cathode, and separator in a jelly roll or stack configuration.

[0031] Process step 216 may include electrical contact, and the composites of two or more electrode units or current collectors can be joined to each other and / or to external electrical contacts or tabs by welding or other means. Tab misalignment, insufficient welding quality, and metal particle impurities are common problems that can occur during process step 216. These problems can be monitored by acoustic measurements and analysis (performed using a mechanism such as system 100) during step 216 or during subsequent steps 218 - 232 in cell manufacturing. The information collected in this way can be used in the feedback path to step 216 for corrective process parameter changes.

[0032] Process step 218 may include case insertion, and one or more electrodes having electrical contacts and separators can be inserted into a suitable case for electrolyte filling and immersion, and for solid electrolyte interphase (SEI) layer formation.

[0033] Process step 220 may include case closure, where the electrode stack or jelly roll is inserted into the case and sealed.

[0034] Process step 222 may include electrolyte filling and soaking. In some examples, electrolyte filling and soaking can be an important process step in battery cell production because the uniformity of electrolyte distribution can directly affect the yield rate of costly downstream processes such as formation and aging. The quality of the electrolyte that wets the pores of the battery cell's electrodes and separators greatly influences structures such as the SEI layer, which is a passivation layer formed on the surface of electrode particles from the decomposition products of the electrolyte. Similar to electrolyte distribution, the uniformity and quality of SEI formation strongly affect the overall quality, performance, and safety of the produced battery cells. Also, the electrolyte wetting quality affects the behavior of the battery cell over time (i.e., the voltage drop rate while the battery cell is electrically insulated from the external circuit). Areas with insufficient wetting have high internal ionic resistance, which affects battery cell performance by reducing discharge capacity, cycle life, and safety. The amount and distribution of the electrolyte within the battery cell are important for the overall performance of the battery cell. Flooding and depletion of the battery cell electrolyte can significantly degrade battery cell performance and cause failures. Therefore, accurate determination of the filling and wetting times is also important to ensure proper and sufficient filling of the electrolyte. Acoustic signal and / or process signal-based monitoring techniques can be used to identify various aspects of electrolyte wetting and distribution, and this information can be used in one or more of the process steps of manufacturing process 200.

[0035] Process step 224 includes pre-charging, where a specific charging voltage is applied to the battery cell for a specific period during electrolyte soaking before formation step 228. In some examples, it may be desirable to apply pre-charging once electrolyte filling is complete in process step 222 (e.g., to ensure that the current collector does not corrode). The level of pre-charging and the period of pre-charging may depend on one or more of the preceding process steps, such as electrolyte filling and electrode density.

[0036] Process step 226 includes closing the filling hole, and the hole of the battery body used for electrolyte filling can be closed. When the hole is closed, further electrolyte filling or depletion, if necessary, is difficult. Therefore, it is important to monitor the preceding process steps to ensure that the hole is closed at the appropriate time in the manufacturing process 200. In some embodiments, the closing of the hole can be related to a battery cell, such as a prismatic cell. It is also important to monitor the quality of the closing of the hole, for example, to prevent moisture ingress if it is sealed by welding.

[0037] Process step 228 includes SEI formation. Lithium-ion battery formation is a process of performing an initial charge / discharge operation in a battery cell. At this stage, the SEI is formed on the electrode (for example, the anode). This layer is susceptible to the influence of many various factors and can affect battery performance over the battery life. Battery formation can take many days depending on the chemistry of the battery. The influence of preceding steps, such as the effect and quality of electrolyte wetting, can be observed during battery formation.

[0038] Process step 230 includes aging, and the decay of the open-circuit voltage of each battery cell (for example, the self-discharge rate of the battery cell) is monitored over time. As described above, the electrolyte wetting quality can affect the aging behavior of the battery cell (for example, the voltage drop rate while the battery cell is electrically insulated from the external circuit).

[0039] Process step 232 includes quality control (QC) and quality assurance (QA), and the DC resistance, AC impedance, charge and / or discharge capacity, and open circuit voltage are electrically monitored. Acoustic signal and / or process signal-based analysis can be performed on the cell in manufacturing step 232 to identify internal defects such as cracks, creases, damage, electrode misalignment, tab misalignment, metal or other foreign particles, insufficient electrolyte distribution, insufficient SEI formation and distribution, etc. In addition to defects, acoustic analysis can be used to estimate the life performance of the cell. This information and other information regarding defects or problems detected in step 232 can be used in the feedback path to the relevant manufacturing process steps to correct errors or improve process yield and cell quality.

[0040] Figure 3 shows an example of a process for using acoustic signals and / or process signals in connection with the manufacture of a battery cell or battery component. As shown, process steps 302a-d may correspond to one or more of process steps 202-232 of manufacturing process 200, or other process steps that may be involved in the manufacture of a battery or its components (e.g., an in-progress batch of cells / components). Further, although Figure 3 is described with reference to a battery manufacturing process, those skilled in the art will recognize that the present technology is not limited to a particular manufacturing process and can be implemented in connection with any other process.

[0041] In one or more of process steps 302a - d, acoustic measurement and analysis 306 can be performed using devices and mechanisms as shown with reference to system 100 of FIG. 1, for example. In corresponding decision block 308 that may follow each block 306, the acoustic measurement and analysis system may determine whether the quality of the battery cells or components in the ongoing batch is as expected (e.g., using reference acoustic measurement data of known battery cells or components, or using other metrics). In each of decision blocks 308, if the quality is as expected (e.g., the measured values or parameters meet or exceed a threshold), it may be determined to proceed to subsequent process steps 302a - d. If the quality metric associated with the corresponding process step does not meet the predetermined requirements, the process 300 may proceed to decision block 310 to determine whether feedback of the information obtained by the system (e.g., acoustic and / or signal measurements) can be used in any of the manufacturing processes for subsequent batches of components / cells, and / or whether feed - forward of the information can be used for one or more components / cells in the ongoing batch.

[0042] In decision block 312, if an error / process drift is detected in the process step where the acoustic analysis was performed, accordingly, adjustments can be made to the process conditions / parameters for the preceding process steps in the manufacture of subsequent batches, as shown in block 304a, for example. In some aspects, the information can be used by the same process step in block 304b to improve the current process step 302b, for example. Similarly, feed - forward information can be used to adjust parameters to compensate for errors / processes in subsequent process steps, as shown in blocks 304c - d, for example. In some examples, the process analysis information / data can be used to make adjustments or improvements to the current process as well as subsequent processes (e.g., feedback and feed - forward of data).

[0043] Next, process 300 is described with reference to an exemplary implementation of an improvement in the process of manufacturing battery cells / components as described in connection with FIG. 2.

[0044] In one example, non-uniform mixing in step 202 results in a density gradient along the coated electrode in step 204, and as a result, after the calendaring process in step 208, non-uniform porosity and meandering of the electrode can occur. The non-uniform porosity of the electrode results in a non-uniform distribution of the electrolyte during filling and immersion in step 222. The insufficient electrolyte distribution throughout the cell results in dry spots within the cell, formation of a poor-quality solid electrolyte interphase (SEI) in step 228, and ultimately insufficient cell performance and lifespan. The density and composition of the electrode slurry after the mixing step 202 can be monitored by acoustic signal and / or process signal-based analysis (such as using the mechanism of system 100). Identification of any defects or concerns in the slurry can be used as feedback or feedforward information. For example, in a feedforward mechanism, if inconsistencies in the slurry mixture such as inhomogeneity, uniformity of the varying amount of solid particles (e.g., the proportion of solids in the mixture), coherence, etc. are identified by acoustic analysis, that information can be used in the feedforward path to the electrolyte filling and immersion step 222 to adapt the immersion process (to improve the performance of this particular cell by making the electrolyte distribution uniform, enabling this lower-porosity electrode within the assembled cell to be immersed for a longer time). In another example, inconsistencies can be reported in the feedback path to the slurry mixer in step 202 to adapt the mixing process (such as increasing the mixing time, mixing speed, mixing temperature, etc.) to adjust for the non-uniform distribution problem of the electrolyte recorded in step 222 based on acoustic analysis.

[0045] In some embodiments, a device (e.g., system 100) can be used to monitor the acoustic signal characteristics of the flow of slurry through a pipe to an electrode coater (e.g., a slot die, a doctor blade, etc.), and this information can be used as feedback for the slurry. The feedforward of acoustic analysis information collected from a slurry mixing tank can also be used to make any adjustments to the flow pipe parameters (e.g., to control the velocity of the slurry flowing through the pipe).

[0046] For example, during the manufacturing process, sedimentation or precipitation of the slurry can cause incomplete mixing, such as by causing slurry regions with a high or low binder content in a slurry mixer, for example, by settling heavier particles. Such effects can change how the slurry deposits on the coater as it passes through the pipe to coat the current collector. In some examples, the acoustic signal and / or monitoring of the process can be used to detect sedimentation and / or precipitation of the slurry.

[0047] In some embodiments, monitoring one or more of the above components or related processes can be used as feedforward information in a subsequent process, such as a coating process. For example, by monitoring one or more of a device (e.g., system 100), adjustments can be determined for a coating process in which the slurry is deposited on the current collector as an electrode slurry. For example, coating process parameters can be controlled based on slurry conditions, leading to decisions regarding, for example, the thickness of the coating layer of the electrode slurry, the flow rate of the slurry at the coater, the width and uniformity of the coating.

[0048] The electrode slurry / current collector can be processed in a drying oven for drying during the coating process. One or more rollers with Tx and Rx transducers embedded for acoustic measurements (such as using a mechanism like system 100) may convey the electrode slurry coating / current collector through the drying process. The acoustic measurement device may provide feedforward information based on the electrode slurry / current collector from steps 202 and 204 that are being monitored to control the drying oven. For example, when specific levels of wetness, thickness, consistency, etc. are determined based on an analysis of acoustic signals and / or process-signal-based measurements made using an acoustic-based measurement device, the optimal drying time and temperature for the electrode slurry / current collector are determined, and this information can be used to program the settings for the drying oven. In some examples, the data collected using acoustic signals and / or process signals can be used with other data, such as manufacturing process data, to determine adjustments or corrections to the process and / or any related process parameters. In some examples of coating and / or calendaring processes (see, for example, process steps 204, 208), the inconsistencies measured in the coating of the electrode slurry may be fed back to the slurry mixing or binder formation process, as an addition or alternative to feeding information forward to the heating / drying stage. The slurry mixing speed, drying temperature, and similar process parameters can be included in the acoustic signal analysis as manufacturing process signals.

[0049] In some examples, the magnitude of compression applied during the electrode formation process, such as the calendaring process in process step 208, may affect the porosity of the electrodes that can be useful for further downstream processes, such as electrolyte filling in process step 222 of FIG. 2. For example, how fast or easily the electrolyte distributes and saturates throughout the cell may be based on the porosity of the electrodes. By analyzing the electrodes during the calendaring process using one or more devices, such as the Tx and Rx transducers shown in system 100, process parameters such as the time to immerse the electrolyte in the battery cell, the amount of electrolyte injected into the battery cell, the number of times a vacuum is drawn during formation (e.g., process step 228), the temperature at which the battery cell is stored for aging (e.g., process step 230), etc., the temperature at which the immersion or other downstream processes are performed can be determined or improved.

[0050] In some examples, electrolyte distribution and wetting characteristics can be analyzed using a set of Tx and / or Rx transducers arranged along various positions of the battery cell, for example, during process step 222. If acoustic signal information regarding the electrolyte distribution and wetting characteristics is used to identify or infer adjustments to the porosity or other characteristics of the electrodes during process step 222, feedback can be provided to affect the coating and calendaring process steps in process steps 204, 208. In some examples, the information can be feed-forwarded from process step 222, such as for determining a specific wetting level used to safely trigger pre-charging in process step 224 (e.g., it may not be safe to perform pre-charging too early when the wetting is not yet complete and dry spots remain).

[0051] In some examples, non-uniform electrolyte distribution or the presence of dry spots may result in non-uniform SEI formation in process step 228 (e.g., on anode material particles). Thus, the non-uniform SEI formation observed using acoustic and / or process signal-based analysis in process step 228 may be fed back to electrolyte filling in process step 222, either in addition to or as an alternative to using the electrolyte distribution information obtained from process step 222 to improve the formation protocol in process step 228 while feeding that information back into electrolyte filling.

[0052] In some examples, feedforward information from one process step to subsequent downstream process steps can affect the quality of the same set or batch of battery cells. In some examples, feedback information from the manufacture of an ongoing batch of battery cells can be useful to affect the manufacturing process of subsequent batches of battery cells. For example, if problems are identified using acoustic and / or process signal-based measurements during the aging of a batch of battery cells in process step 230 or during quality control (QC) in process step 232, this information can be used to improve one or more of process steps 202-228 for subsequent batches of battery cells. In some examples, feedback information obtained regarding materials and components during the manufacture of one cell type (e.g., having a first form factor and / or a first chemical property) in one production line or facility can be useful for process adaptation in the manufacture of another cell type (e.g., having a second form factor and / or a second chemical property) in the same or a different production line or facility. In some examples, in-line measurements can be applied immediately to improve process conditions, while in some examples, they can be used to create a reference database or data repository of process conditions.

[0053] Figure 4 shows a block diagram of a battery manufacturing analysis platform 400. In some examples, the battery analysis platform 400 may include an acoustic signal analysis system 402 (e.g., system 100). In some examples, the acoustic analysis system may include hardware and software components that can be used to collect and analyze data related to battery manufacturing and battery health. In some examples, the acoustic signal analysis system 402 can perform an Electrochemical Acoustic Signal Inquiry (EASI), which may include hardware and software configured to determine the state and health of a battery and the battery manufacturing process and to monitor these processes over time.

[0054] In some examples, EASI technology may utilize a number of data processing and analysis techniques, including machine learning tools and concepts. These techniques can be applied to acoustic signal data that the acoustic signal analysis system 402 can measure and collect, as well as any other manufacturing or battery data streams. In some aspects, the acoustic signal analysis system 402 may include hardware for collecting acoustic data, as well as software, algorithms, and data processing algorithms for providing data related to the battery, battery components, and / or the battery manufacturing process.

[0055] In some examples, the inputs to the acoustic signal analysis system 402 may include ultrasonic data 404, functional test results 406, other process inspection data 408, data from process equipment 410, supplier quality control data 412, custom data streams 414, and / or any other data related to the battery and / or the battery manufacturing process. In some aspects, the outputs from the acoustic signal analysis system 402 may include real-time factory monitoring 416, in-line pass / fail inspection results 418, line quality and yield monitoring 420, yield management 422, and / or any other relevant output parameters / metrics related to the battery and / or the battery manufacturing process.

[0056] FIG. 5 is a flowchart showing an example method 500 for controlling a battery manufacturing process. The process of FIG. 5 may be implemented by the apparatus 100 of FIG. 1 and its components such as, for example, the processor 110. It will be apparent to those skilled in the art that the processor 110 may have one or more memories (non-transitory computer-readable media) storing computer-readable instructions that, when executed by one or more processors, cause the processor 110 to perform the steps of FIG. 5.

[0057] In block 502, method 500 includes performing signal-based analysis during a first process step. In some examples, performing signal-based analysis may include transmitting a first acoustic signal toward a component associated with the first process step, receiving at least a second acoustic signal corresponding to the first acoustic signal, and determining an acoustic parameter based on the first acoustic signal and the second acoustic signal. For example, the Tx transducer 104 may be used to transmit an acoustic signal toward the sample 102, and the Rx transducer 106 may be used to receive the corresponding acoustic signal. In some aspects, the processor 110 may be used (e.g., together with the acoustic pulser / receiver 108) to determine an acoustic parameter based on the transmitted and received acoustic signals.

[0058] In block 502, the method includes determining at least one adjustment to a second process step based on signal analysis performed during the first process step, where the first process step and the second process step correspond to a battery manufacturing process. In some examples, the at least one adjustment may be related to at least one of the density of the electrode slurry, the precipitation of the electrode slurry, the thickness of the coating, the speed of the slurry coater, the oven drying time, and the oven drying temperature. In some aspects, the acoustic parameter may be used to determine that at least one manufacturing parameter is below a threshold requirement, and the at least one adjustment may be configured to adjust the at least one manufacturing parameter (e.g., to meet the threshold requirement).

[0059] In block 504, the method includes providing information related to at least one adjustment to a second process step. In some examples, the second process step may be prior to the first process step, and providing the information may include feedback. In some cases, the second process step may be after the first process step, and providing the information may include feedforward. In some examples, the first process step and the second process step may correspond to the same process step in a battery manufacturing process. FIG. 6 shows an example system that may be used as the processor of FIG. 1 according to an aspect of the present disclosure. The example system shown may be used to implement the processor 110 of FIG. 1. More suitable systems will be apparent to those skilled in the art when implementing various embodiments. Those skilled in the art will also readily recognize that other systems are possible.

[0060] FIG. 6 shows an example of a bus computing system 600 in which the components of the system communicate with each other electrically using a bus 605. The computing system 600 may include a system bus 605 that can couple various system components, including a processing unit (CPU or processor) 610, a system memory 615, a read-only memory (ROM) 620, and a random access memory (RAM) 625, to the processor 610. The computing system 600 may include a cache 612 of high-speed memory that is directly connected in the vicinity of the processor 610 or integrated as part of the processor 610. The computing system 600 may copy data from the memory 615, ROM 620, RAM 625, and / or storage device 630 to the cache 612 for quick access by the processor 610. Thus, the cache 612 may provide a performance improvement that avoids processor delays while waiting for data. These modules and other modules may control the processor 610 to perform various operations. Other system memories 615 may similarly be available. The memory 615 may include a number of different types of memory having various performance characteristics. The processor 610 may include any general-purpose processor and hardware or software modules, such as service (SVC) 1 632, SVC2 634, SVC3 636, etc., stored in the storage device 630 and configured to control the processor 610, and a dedicated processor in which software instructions are incorporated into an actual processor design. The processor 610 may basically be a fully self-contained computing system including multiple cores or processors, buses, memory controllers, caches, etc. The multi-core processor may be symmetric or asymmetric.

[0061] To enable user interaction with the computing system 600, the input device 645 may represent any number of input mechanisms such as, for example, a microphone for voice, a touch-protected screen for gesture or graphic input, a keyboard, a mouse, motion input, voice, etc. The output device 635 may also be one or more of a number of output mechanisms known to those skilled in the art. In some examples, a multimodal system may enable a user to provide multiple types of input to communicate with the computing system 600. The communication interface 640 may control and manage user input and system output. Since there is no limitation on operation in any particular hardware configuration, the basic features here may be easily replaced when an improved hardware or software configuration is developed.

[0062] The memory device 630 may be non-volatile memory and may be, for example, a magnetic cassette, a flash memory card, a solid state memory device, a digital versatile disk, a cartridge, a random access memory, a read-only memory, and hybrids thereof, a hard disk or other types of computer-readable media capable of storing data accessible by a computer.

[0063] As described above, the memory device 630 may include software SVC 632, 634, 636 for controlling the processor 610. Other hardware or software modules are conceivable. The memory device 630 may be connected to the system bus 605. In some embodiments, a hardware module that performs a particular function may include software components stored in a computer-readable medium in association with the necessary hardware components such as, for example, the processor 610, the bus 605, the output device 635, etc. to execute the function.

[0064] One of ordinary skill in the art will recognize that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to through the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0065] Furthermore, one of ordinary skill in the art will recognize that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. One of ordinary skill in the art may implement the described functionality in varying ways for each particular application, but such implementations should not be construed as departing from the scope of the present disclosure.

[0066] Note that the above disclosure shows exemplary aspects of the present technology, but various changes and modifications can be made herein without departing from the scope of the present technology as defined by the appended claims. The functions, steps, and / or operations of the method claims according to the aspects of the present disclosure described herein need not be performed in any particular order. Also, elements of the present disclosure are described in the singular or may be recited in the claims, but the plural is also contemplated unless a limitation to the singular is explicitly stated.

[0067] Claim language or other language that recites a set of "at least one" and / or a set of "one or more" in this disclosure indicates that one member of the set or multiple members (in any combination) satisfy the claim. For example, claim language that recites "at least one of A and B" or "at least one of A or B" means A, B, or A and B. In other examples, claim language that recites "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 language of a set of "at least one" and / or a set of "one or more" does not limit the set to the items listed within the set. For example, claim language that recites "at least one of A and B" or "at least one of A or B" means A, B, or A and B, and can further include items not listed in the set of A and B.

Claims

1. 1. A method of controlling a manufacturing process, comprising the steps of: performing a signal-based analysis during a first process step; determining at least one adjustment to a second process step based on the signal-based analysis performed during the first process step, the first process step and the second process step corresponding to a battery manufacturing process; providing information related to said at least one adjustment to said second process step; A method for providing the above.

2. The method of claim 1 , wherein the second process step precedes the first process step, and the providing of information comprises feedback.

3. The method of claim 1 , wherein the second process step is after the first process step, and the providing of information comprises feedforward.

4. The method of claim 1 , wherein the first process step and the second process step correspond to a same process step in the battery manufacturing process.

5. Conducting a signal-based analysis during the first process step includes: transmitting a first acoustic signal toward a component associated with the first process step; receiving at least a second acoustic signal corresponding to the first acoustic signal; determining acoustic parameters based on the first acoustic signal and the second acoustic signal; The method of claim 1 , comprising:

6. determining, based on the acoustic parameters, that at least one manufacturing parameter is below a threshold requirement, wherein the at least one adjustment is configured to adjust the at least one manufacturing parameter. The method of claim 5 further comprising:

7. 10. The method of claim 1, wherein the at least one adjustment relates to at least one of electrode slurry density, electrode slurry settling, coating thickness, slurry coater speed, oven drying time, and oven drying temperature.

8. 1. An apparatus for controlling a manufacturing process, comprising: At least one memory; coupled to the at least one memory; performing a signal-based analysis during a first process step; determining at least one adjustment to a second process step based on the signal-based analysis performed during the first process step, wherein the first process step and the second process step correspond to a battery manufacturing process; providing information related to said at least one adjustment to said second process step; At least one processor configured to An apparatus comprising:

9. The apparatus of claim 8 , wherein the second process step precedes the first process step, and the providing of information comprises feedback.

10. 10. The apparatus of claim 8, wherein the second process step is later than the first process step, and the providing of information comprises feedforward.

11. The apparatus of claim 8 , wherein the first process step and the second process step correspond to a same process step in the battery manufacturing process.

12. and at least one transducer coupled to the at least one processor, the at least one processor further comprising: transmitting a first acoustic signal via the at least one transducer towards a component associated with the first process step; receiving at least a second acoustic signal corresponding to the first acoustic signal via the at least one transducer; The apparatus of claim 8 , configured to determine an acoustic parameter based on the first acoustic signal and the second acoustic signal.

13. The at least one processor further comprises: The apparatus of claim 12 , further configured to determine based on the acoustic parameters that at least one manufacturing parameter is below a threshold requirement, and wherein the at least one adjustment is configured to adjust the at least one manufacturing parameter.

14. The apparatus of claim 8 , wherein the at least one adjustment relates to at least one of electrode slurry density, electrode slurry settling, coating thickness, slurry coater speed, oven drying time, and oven drying temperature.

15. When executed by one or more processors, the one or more processors: performing a signal-based analysis during a first process step; determining at least one adjustment to a second process step based on the signal-based analysis performed during the first process step, wherein the first process step and the second process step correspond to a battery manufacturing process; A non-transitory computer readable storage medium having instructions stored thereon that cause the second process step to provide information related to the at least one adjustment.

16. 16. The non-transitory computer-readable storage medium of claim 15, wherein the second process step precedes the first process step, and the providing of information comprises feedback.

17. 16. The non-transitory computer-readable storage medium of claim 15, wherein the second process step is after the first process step, and the providing of information comprises feedforward.

18. When executed by one or more processors, the one or more processors: transmitting a first acoustic signal via the at least one transducer towards a component associated with the first process step; receiving at least a second acoustic signal corresponding to the first acoustic signal via the at least one transducer; 16. The non-transitory computer-readable storage medium of claim 15, comprising instructions for determining an acoustic parameter based on the first acoustic signal and the second acoustic signal.

19. When executed by one or more processors, the one or more processors:

20. The non-transitory computer-readable storage medium of claim 18, comprising instructions for determining, based on the acoustic parameters, that at least one manufacturing parameter is below a threshold requirement, and wherein the at least one adjustment is configured to adjust the at least one manufacturing parameter.

20. 16. The non-transitory computer-readable storage medium of claim 15, wherein the at least one adjustment is related to at least one of electrode slurry density, electrode slurry settling, coating thickness, slurry coater speed, oven drying time, and oven drying temperature.

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