FIXTURING MECHANISM WITH LOAD SENSORS FOR ACOUSTIC TESTING OF BATTERY SAMPLES

One or more aspects of the present disclosure are directed to fixturing mechanisms for placement of battery cells inside an ultrasonic testing system. The disclosed fixturing mechanisms enable accurate and predictable loading, placement, and unloading of battery cells inside ultrasonic testing systems allowing all faces of battery cells of different types (e.g., pouch cells, prismatic cells, cylindrical cells, etc.) to have sufficient exposure to transmission and reception of acoustic signals. This fixturing mechanism furthers the goal of providing a robustly designed ultrasonic test system and producing accurate inspection results for batteries.

FIELD OF DISCLOSURE

Disclosed aspects are directed to apparatus and systems for fixturing and handling batteries for acoustic inspection designed in such a way that the acoustic source and sensors cover the entire or part of the battery cells surface area and the fixturing can be scaled to be implemented in high throughput production environments.

BACKGROUND

Demand for production of battery cells is on the rise owing to an increase in their use across various industries such as consumer electronics, automotive, clean energy, etc. Efficient and fast battery diagnostics methods are important for increasing quality, lifetime, and manufacturing process efficiency for batteries. In the case of manufacturing and production, reducing costs (e.g., price per kilowatt-hour (kWh)) is an important goal. Production costs and quality can be reduced by optimizing existing processes and/or introducing new technologies. For example, technological advances in the area of improved monitoring, manufacturing, and diagnostics can lead to cost efficiencies by shortening production process times (thus also reducing energy consumption during production), reducing waste due to damaged cells and cell parts, improving quality, etc.

BRIEF SUMMARY

Aspects of the present disclosure are directed to fixturing mechanisms for placing battery cells in a battery testing apparatus for ultrasonic inspect of said battery cells.

In one aspect, an apparatus includes a first piece coupled to a second piece, wherein the first piece is configured to open relative to the second piece for placing a battery cell between the first piece and the second piece for acoustic inspection; and an opening formed in between the first piece and the second piece that provides exposure of both sides of the battery cell for the acoustic inspection. after closing the first piece.

In another aspect, the battery cell is a pouch cell.

In another aspect, the apparatus is inserted into an ultrasonic test system for the acoustic inspection.

In another aspect, the apparatus is attached to a moving mechanism for placement within the ultrasonic test system.

In another aspect, the first piece and the second piece are coupled together using at least one aligning pin and at least one magnet-based coupling mechanism.

In one aspect, an apparatus includes a first side, a second side, and a bottom portion connecting the first side and the second side, wherein a U-shaped opening is formed between the first side, the bottom portion and the second side for placement of a battery cell therein for acoustic inspection.

In another aspect, the battery cell is a Prismatic Battery Cell.

In another aspect, the first side and the second side are movable to accommodate battery cells of different lengths to be placed within the U-shaped opening.

In another aspect, the first side and the second side are controlled to move horizontally for accommodating the battery cells of different lengths.

In another aspect, the first side and the second side are independently controlled via separate actuators.

In another aspect, the first side is spring-loaded and the second side is fixed.

In another aspect, the first side is configured to move horizontally to adjust side of the U-shaped opening for receiving the battery cell therein.

In another aspect, each of the first side and the second side include one or more rollers configured to facilitate sliding the battery cell to fit within the U-shaped opening.

In one aspect, an apparatus includes a first structure, and a second structure opposite the first structure, wherein a battery cell is placed in between the first structure and the second structure to be rotated by the first structure and the second structure for acoustic inspection.

In another aspect, the battery cell is a cylindrical battery cell.

In another aspect, each of the first structure and the second structure is formed of a single cylindrical roller configured to spin for rotating the battery cell for the acoustic inspection.

In another aspect, each of the first structure and the second structure comprises at least two rollers.

In another aspect, one of the at least two rollers in one of the first structure or the second structure is controlled via an actuator for rotating the battery cell.

In another aspect, remaining ones of the at least two rollers in the first structure and the second structure are configured to rotate as a result of the battery cell rotating by the one of the at least two rollers.

In another aspect, the actuator is a pneumatic actuator.

DETAILED DESCRIPTION

Certain aspects and embodiments of this disclosure are provided in the following description and related drawings. Alternate aspects may be devised without departing from the scope of the disclosure. Additionally, well-known elements of the disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the disclosure.

Demand for production of battery cells is on the rise owing to an increase in their use across various industries such as consumer electronics, automotive, clean energy, etc. A non-limiting application of battery cells is the electrical vehicle (EV) industry. According to various market research, the industry needs massive buildouts to meet EV demand by 2030 (around 15 times the current capacity). The cost of battery cell production should decrease by around 40% according to some estimates. Furthermore, as evidence thereof have already been seen, reliability of EV batteries is critical as human and financial remedies of EV recalls due to faulty batteries are immense (already to the tune of more than $3B in 2020-2021).

Battery manufacturing processes are not without challenges. For example, the cost of raw materials is on the rise and issues during manufacturing can lead to poor quality battery cells and hence unreliable battery cells being incorporated into and utilized in their respective applications such as in EVs, which can ultimately lead to the costly failures mentioned above.

For instance, battery defects that can lead to poor battery cell performance, a catastrophic battery (and/or device) failure, etc. Such defects can arise during the manufacturing process or during regular operation of a battery after the battery is placed in a device. Such defects are difficult to detect because they are generally deep within the battery cell and hidden from non-invasive imaging methods or are not substantial enough to be detected through electrical inspection methods until the defect has caused substantial damage/degradation to the battery.

In some examples, manufacturing defects can include, but are not limited to, folds, wrinkles, or holes in traditional polymer-based separator materials, cracks or fractures in solid-state ceramic based separators, dry spots within the cell due to poor electrolyte saturation, electrode holes, folds, delamination, or layer misalignment, foreign object debris, burrs, metallic particle inclusions, tab defects including tears, folds, and poor quality welds, electrode misalignment, electrode holes and folds, electrode material delamination, among others.

Operational defects can include, but are not limited to, the plating of lithium metal (e.g., dendritic growth or otherwise) on the anode material, dry spots within the cell due to electrolyte degradation, the evolution of gasses resulting from electrolyte or other chemical decomposition, among others. All of these defects can cause micro-shorts in the battery that, if allowed to propagate, can lead to early cell death, rapid loss of capacity, and/or catastrophic failure.

Currently available methods for studying defective batteries include x-ray or CT inspection of cell and tearing down a battery after it has been flagged as underperforming, a safety hazard, or a failure in the field.

It is difficult to study defective batteries because of the challenges associated with properly attributing the impact and causality of a specific defective component towards the failure of a battery. Furthermore, the availability of defective batteries is limited because of the extensive resources and safety considerations surrounding their production and transport. Additionally, intentional production of batteries with known and clearly defined defects is difficult to control from a process standpoint. Defects in batteries need to be studied to improve battery development and manufacturing processes, which cannot be done without adequate samples that safely and effectively model these defects.

When conducting ultrasound-based inspection tests on batteries, the wide parameter space on the test apparatus and the sample form factor can lead to challenges involving non-recurring engineering and design tasks. For example, a subset of ultrasonic test settings may be optimized to see a folded separator in a Lithium-ion battery pouch cell, but may not be able to detect electrode inclusions in the same cell. Conversely, observing a separator fold may require different ultrasonic settings in prismatic or hard can cells versus pouch cells. The wide parameter space within ultrasound as it pertains to testing batteries can require that the test system be designed so that different transducer types can be accommodated, different test methodologies can be executed electronically, and/or that the test bed can accommodate most of the common battery form factors.

Ultrasonic tests are also highly influenced by external factors. Even in the most basic tests, results can vary drastically with fluctuations in mechanical alignment, contact force, external temperature, pressure and environment, as well as within the ultrasonic coupling used to transfer the ultrasonic pulse from the transducer to the test sample. A robustly designed ultrasonic test system as described herein can factor all of these challenges in order to produce accurate and reproducible results.

The systems and techniques described herein for detecting defects in batteries can address the foregoing challenges (as well as other challenges). More specifically, the present disclosure is directed to fixturing mechanisms for placement of battery cells inside an ultrasonic testing system. The disclosed fixturing mechanisms enable accurate and predictable loading, placement, and unloading of battery cells inside ultrasonic testing systems allowing all faces of battery cells of different types (e.g., pouch cells, prismatic cells, and cylindrical cells) to have sufficient exposure to transmission and reception of acoustic signals. This fixturing mechanism furthers the goal of providing a robustly designed ultrasonic test system and producing accurate inspection results for batteries.

Description of exemplary systems for performing non-invasive and acoustic measurement of battery cells is provided with reference toFIGS.1and2. The disclosure then provides example embodiments of a fixturing mechanism for placing Prismatic Battery Cells inside an ultrasonic test system with reference toFIGS.3A-D. Example fixturing mechanism for placing pouch cells inside an ultrasonic test system will be described with reference toFIGS.4A-C. Example fixturing mechanism for placing cylindrical cells in an ultrasonic test system will be described with reference toFIGS.5-7. An example method of placing battery cells inside a fixturing mechanism will be described with reference toFIG.8. The disclosure concludes with a description of an example device and system architecture with reference toFIG.9.

FIG.1illustrates an example system for analyzing a sample using acoustic signal-based analysis according to some aspects of the present disclosure. System100may include sample102. Sample102can include a battery cell or component thereof in any stage of production or manufacture of the battery cell or the individual components. In some examples, sample102can include a battery cell, electrolytes in various stages of wetting/distribution through a battery cell, one or more electrodes of the battery cell, thin films, separators, coated sheets, current collectors, electrode slurries, or materials for forming any of the above components during any stage of their fabrication. System100can include a transmitting transducer Tx104or other means for sending excitation sound signals into the battery cell (e.g., for transmitting a pulse or pulses of ultrasonic or other acoustic waves, vibrations, resonance measurements, etc., through the battery cell). System100can further include a receiving transducer Rx106or other means for receiving/sensing the sound signals, which can receive response signals generated from signals transmitted by transmitting transducer Tx104. Any type of known or to be developed transducer for transmitting and receiving acoustic signals may be used as transmitting transducer Tx104. Transmitted signals from transmitting transducer Tx104, from one side of sample102on which transmitting transducer Tx104is located, may include input excitation signals. Reflected signals, e.g., from another side of sample102, may include echo signals. It is understood that references to response signals may include both the input excitation signals and the echo signals. Further, transmitting transducer Tx104may also be configured to receive response signals, and similarly, receiving transducer Rx106may also be configured to transmit acoustic signals. Any type of known or to be developed transducer for transmitting and receiving acoustic signals may be used as receiving transducer Rx106. Therefore, even though separately illustrated as Tx and Rx, the functionalities of each of transmitting transducer Tx104and receiving transducer Rx106may be for both sending and receiving acoustic signals. In various alternatives, even if not specifically illustrated, one or more Tx transducers and one or more Rx transducers can be placed on the same side or wall of sample102, or on different (e.g., opposite) sides. Throughout this disclosure, reference may be made to a transducer pair (a transmitting transducer and a receiving transducer). Transmitting transducer Tx104and receiving transducer Rx106may form a pair of transducers.

Acoustic pulser/receiver108can be coupled to transmitting transducer Tx104and receiving transducer Rx106for controlling the transmission of acoustic signals (e.g., ultrasound signals) and receiving response signals. Acoustic pulser/receiver108may include a controller108-1for adjusting the amplitude, frequency, and/or other signal features of the transmitted signals. Acoustic pulser/receiver108may also receive the signals from receiving transducer Rx106. In some examples, acoustic pulser/receiver108may be configured as a combined unit, while in some examples, an acoustic pulser for transmitting excitation signals through transmitting transducer Tx104can be a separate unit in communication with a receiver for receiving signals from receiving transducer Rx106. Processor110in communication with acoustic pulser/receiver108may be configured to store and analyze the response signal waveforms according to this disclosure. Although representatively shown as a single processor, processor110can include one or more processors, including remote processors, cloud computing infrastructure, etc.

In some examples, various acoustic couplants such as couplants103and105can be used (e.g., solid, liquid, or combinations thereof) for making or enhancing contact between transmitting transducer Tx104, receiving transducer Rx106, and sample102. Furthermore, various attachment or fixturing mechanisms (e.g., pneumatic, compression, screws, springs etc.) can also be used for establishing or enhancing the contact between transmitting transducer Tx104, receiving transducer Rx106, and sample102.

Although not explicitly shown inFIG.1, more than one transmitting transducer Tx and/or more than one receiving transducer Rx can be placed in one or more spatial locations across sample102. This allows studying a spatial variation of acoustic signal features across sample102. A multiplexer can be configured in communication with the acoustic pulser/receiver108for separating and channeling the excitation signals to be transmitted and the response signals received. This will be further described below with reference toFIG.2.

FIG.2illustrates another example system for analyzing a sample using acoustic signal-based analysis according to some aspects of the present disclosure. In comparison withFIG.1, system200ofFIG.2illustrates a system in which multiple pairs of transmitting and receiving transducers are used for transmitting signals through a sample under testing (e.g., a battery cell) and performing acoustic signal-based analysis of the sample.

System200includes several transmitting transducers Tx202(each of which may be the same as transmitting transducer Tx104ofFIG.1). While an array of four examples transmitting transducers Tx202are shown inFIG.2, the disclosure is not limited to four. Any number of transducers may be used (e.g., any number of transmitting transducers Tx ranging from 1 to 10, 20, etc.).

Similarly, system200includes a number of receiving transducers Rx204(each of which may be the same as receiving transducer Rx106ofFIG.1). Receiving transducers Rx204may also be referred to as receiving sensors204. While an array of four examples receiving transducers Rx204are shown inFIG.2, the disclosure is not limited to four. Any number of transducers may be used (e.g., any number of receiving transducers Rx ranging from 1 to 10, 15, 20, etc.). Any given transmitting transducer Tx202and receiving transducers Rx204may form a transducer pair (FIG.2illustrates four transducer pairs).FIG.2also illustrates a multiplexer206coupled to the array of four transmitting transducers Tx202and a multiplexer208coupled to the array of four receiving transducers Rx204. As described above, each one of multiplexers206and208may be configured to be in communication with the acoustic pulser/receiver108for separating and channeling the excitation signals to be transmitted and the response signals received, respectively. In some examples, various acoustic couplants such as couplants203and205can be used (e.g., solid, liquid, or combinations thereof) for making or enhancing contact between transmitting transducers Tx202, receiving transducers Rx204, and sample102. Furthermore, various attachment or fixturing mechanisms (e.g., pneumatic, compression, screws, etc.) can also be used for establishing or enhancing the contact between transmitting transducers Tx202, receiving transducers Rx204, and sample102. In another example, one or more pairs of transmitting transducer Tx and receiving transducer Rx can be translated on the surface of the sample/battery cell to collect acoustic data from various positions on the sample surface. The spatial resolution of the acoustic data collected can be controlled by moving the transducer pair(s) with certain pitch to get higher spatial coverage of the battery cell sample area.

Spacing between transmitting transducers Tx202and receiving transducers Rx204may be uniform and the same. System200also includes additional elements such as sample102, ultrasonic pulser/receiver108(controller108-1), processors110, each of which may be the same as the corresponding counterpart described above with reference toFIG.1and hence will not be described further for sake of brevity.

Example systems100and200may have any shape or form, may be standalone systems, may be portable or stationary, etc. Example systems100and200may also be referred to as ultrasonic test systems.

Ultrasonic battery inspection using a through transmission transducer setup requires access on two sides of a prismatic or pouch cell and around the entire circumference of a cylindrical cell. In order to allow for this inspection a battery Fixture is proposed to allow for the necessary cell face contact for the inspection.

Constraints to be observed for such battery Fixture include the following. First, the sample is to be accessible on two sides of a prismatic or pouch cell and around the entire circumference of a cylindrical cell. Second, the sample is to be accurately and repeatably placed in the Fixture. This way the ultrasonic measurement is repeatable both when scanning a sample multiple times and from sample to sample. Third, the loading and unloading of the sample must be done without the need for any tools. In instances where there is a human operator, it should be easy for the operator to test a batch of samples on the system. If a machine is loading the sample, it is not realistic to have a tool required for loading and unloading the cell. Fourth, there is to be a feedback system in place to indicate if the cell has been properly loaded. This acts as a safety and reliability check for the system software. With this feedback system in place, the ultrasonic system cannot take a scan without a sample. Fifth, in order to maximize the scan area of the cell, the Fixture is to hold onto as little of the cell face as possible. Sixth, the sample cannot be damaged by the fixturing method.

With example systems used for acoustic signal analysis of batteries described with reference toFIGS.1and2, the disclosure now turns to example fixturing mechanism for placement of battery cells of different types in an ultrasound test systems such as example systems100and200ofFIGS.1and2, to address challenges and constraints described above.

FIG.3Aillustrates an example fixturing mechanism, in an open position, for placing a Prismatic Battery Cell in an ultrasonic test system according to some aspects of the present disclosure. Prismatic battery cell302may be placed inside an opening (a U-shaped opening) of fixture304. Opening of fixture304may be an L-shaped opening between side306, side308, and bottom portion310. While not shown inFIG.3A, a mechanical arm (that may be electronically and automatically driven) may place prismatic battery cell302in the opening of fixture304. Alternatively, prismatic battery cell302may be manually placed in the opening of fixture304.

Once prismatic battery cell302is placed inside fixture304, prismatic battery cell302may be secured inside the opening of Fixture304for acoustic inspection using a locking mechanism. Such locking mechanism may be formed of movable arm312and movable arm314. InFIG.3A, movable arm312and movable arm314are shown in open position. Movable arm312and movable arm314may be driven via any known or to be developed mechanism. For example, movable arm312and movable arm314may be pneumatically driven via any know or to be developed actuator. In some examples, both movable arm312and movable arm314are driven (controlled) using a single actuator, hence ensure synchronized movement of movable arm312and movable arm314. In another example, each of movable arm312and movable arm314may be driven (controlled) using separate actuators. The separate actuators may be calibrated to synchronously move movable arm312and movable arm314.

FIG.3Billustrates an example fixturing mechanism, in a locked position, for placing a Prismatic Battery Cell in an ultrasonic test system according to some aspects of the present disclosure.FIG.3Billustrates Fixture304with prismatic battery cell302placed inside opening of fixture304and locked (closed). Compared toFIG.3A, movable arm312and movable arm314are in a locked position securing prismatic battery cell302within fixture304for acoustic inspection.

Fixture304ofFIGS.3A-Bmay be made of any known or to be developed material. Shape and size of Fixture304as well as operation thereof, are not limited to that shown inFIGS.3A-Band may include any other alternative design, shape and manner of operation. Furthermore, Fixture304may be affixed to ultrasonic test system and/or housing within which ultrasonic test system (e.g., system100and/or200) sit using any known or to be developed technique such as using screws, bolts, etc.

FIG.3Cillustrates another example fixturing mechanism for placing a Prismatic Battery Cell in an ultrasonic test system according to some aspects of the present disclosure. Fixture316ofFIG.3Chas a different design compared to fixture304ofFIGS.3A-Bin that compared to movable arm312and movable arm314, arm318and arm320are not movable in horizontal direction but rather arm318includes a number of spring-loaded rollers that can move horizontally to adjust for variations in length of prismatic battery cell302. Arm320includes a number of fixed (in position) rollers. Rollers inside arm318and arm320may be placed to be in contact with sides of prismatic battery cell302in order to facilitate placement and sliding of prismatic battery cell302to be placed inside the opening of Fixture316. Arm318and arm320and associated rollers and springs used therein are more fully described below with reference toFIG.3D.

FIG.3Dillustrates a cross sectional view of example fixturing mechanism ofFIG.3Caccording to some aspects of the present disclosure.FIG.3Dis a cross sectional view of Fixture316with prismatic battery cell302placed therein along the A-A′ line to shown inner components of arm318and arm320.

As shown, inside arm318, there may be two springs, namely spring322and spring324. The number of springs are not limited to two and may be one or more than two depending on design parameters, constraints, and/or preferences. Each spring may be placed inside a casing to fix the respective one of spring322and spring324in place. Spring322and spring324may be coupled to adjuster326such that the force of spring322and spring324can move adjuster326horizontally, thus allowing adjuster326to simultaneously move roller(s)328horizontally. In other words, adjuster326may function to simultaneously move all roller(s)328synchronously.

Arm318also includes a number of roller(s)328. For ease of illustration,FIG.3Dshows six roller(s)328inside arm318but only one such roller is numbered. The number of roller(s)328are not limited to that shown inFIG.3Dand may be more or less.

Arm320also includes a number of roller(s)330. For ease of illustration,FIG.3Dshows six roller(s)330inside arm318but only one such roller is numbered. The number of roller(s)330are not limited to that shown inFIG.3Dand may be more or less. In some examples, the number of roller(s)328and roller(s)330may be the same. In another example, the number of roller(s)328and roller(s)330may be different.

Given that roller(s)328are driven by spring322and/or spring324, roller(s)328may be referred to as spring-loaded rollers while roller(s)330are fixed in position and hence may be referred to as fixed rollers.

By having spring-loaded roller(s)328on one side (inside arm318) of fixture316, as prismatic battery cell302is placed inside opening of fixture316, one side of prismatic battery cell302is positioned against roller(s)330and spring322and spring324may move roller(s)328to adjust for/accommodate for length of prismatic battery cell302. Once placed inside the opening, spring322and spring324may expand to move roller(s)328to be in contact with the side of prismatic battery cell302and hence ensure that prismatic battery cell302is secured in place (with no room to wobble) for performing acoustic measurement(s) across prismatic battery cell302.

Cross section view ofFIG.3Dalso reveals how different components of Fixture316may be coupled to one another (e.g., pieces of bottom portion310may be fastened using screw(s)332.

FIG.4Aillustrates an example of computer-generated rendering of a fixturing mechanism for placing a pouch cell in an ultrasonic test system according to some aspects of the present disclosure. Fixture402may include upper side404and lower side406. Upper side404and lower side406may be connected (e.g., via a hinge (not shown)) so that Fixture402may be opened and closed. Once opened, a pouch cell (to be acoustically measured) may be placed in between upper side404and lower side406to be exposed via opening408. In this manner both sides of a pouch cell can be exposed to (in contact with) transmitting transducers and receiving transducers such as transmitting transducer Tx104and/or transmitting transducers Tx202and receiving transducer Rx106and receiving transducers Rx204ofFIGS.1and2.

Once closed, upper side404and lower side406may be secured together (hence securing pouch cell placed therein for acoustic inspection). For instance, upper side404and lower side406may be aligned using aligning pins412and may thereafter be secured together using magnet-based coupling mechanism410. Mechanisms for aligning and securing upper side404and lower side406is not limited to that described here and may be achieved according to any other known or to be developed mechanism/process.

FIG.4Billustrates images of an actual fixturing mechanism for pouch cells according to some aspects of the present disclosure. WhileFIG.4Aillustrates a computer-generated rendering of Fixture402,FIG.4Bprovides three example pictures of actual Fixture402in three different stages. Stage 1414shows lower side406(Fixture402is open) for a pouch cell to be placed thereon (within opening408).

Stage 2416shows that pouch cell420is placed on lower406.

stage 3418shows that upper side404is placed on pouch cell420and lower side406(Fixture402is closed) and secured via magnet-based coupling mechanism410.

FIG.4Cillustrates images of an actual fixturing mechanism for pouch cells in operation within an ultrasonic test system according to some aspects of the present disclosure.FIG.4illustrates Fixture402in-use within an actual ultrasonic test system. Similar toFIG.4B, three stages of Fixture402in-use are shown inFIG.4C.

Stage 1422shows Fixture402in an open position and ready for a pouch cell to be loaded therein for acoustic inspection. As can be seen from Stage 1422, Fixture402may be affixed to a plate428. Plate428may itself be attached to moving mechanism430such that when a pouch cell is placed inside Fixture402, pouch cell may be moved horizontally inside ultrasonic test system432to be acoustically inspected.

Stage 2424comes after stage 1424whereby pouch cell420is now placed inside Fixture402while Fixture402remains in an open position.

Stage 4426shows that after placement of pouch cell420inside Fixture402, Fixture402is closed and ready to be inserted into ultrasonic test systems432using moving mechanism430for acoustic inspection.

Fixture402and/or any other components described with reference toFIGS.4A-Cmay be made of any known or to be developed material suitable for inspection of battery cells. Furthermore, dimensions, design parameters, shape and/or type of Fixture402(and similarly Fixture304and/or Fixture316) are not limited to those shown inFIGS.3A-DandFIGS.4A-Cand can include any other dimension, parameter, shape, and/or can be made of other material suitable for carrying acoustic inspection of battery cells.

Furthermore, similar to example Fixtures described with reference toFIGS.3A-D, pouch cells such as pouch cell420may be placed inside Fixture402using an automated and mechanical system. Alternatively, pouch cells may be manually placed inside Fixture402.

FIG.5illustrates an example ultrasonic test system for acoustic inspection of cylindrical battery cells according to some aspects of the present disclosure.

Example system500for inspection of cylindrical battery cells can include a casing502made out of any known or to be developed material. A glass top504may cover a portion of system500and include an opening506for receiving a cylindrical battery cell to be acoustically inspected. A holding mechanism508may be used for holding and/or rotating cylindrical battery cell to be inspected. Examples of holding mechanism508will be further described below with reference toFIGS.6and7. Additionally, system500may include a stage510for mounting and installing transducers for multiple ways of inspecting cylindrical acoustic cells.FIG.5further illustrates an example z-translation motor512. Motor512is configured to allow full rotation of a cylindrical battery cell for acoustic inspection with infinite resolution. For instance, motor512can control movement of multiple idlers to rotate a cylindrical battery cell.

FIG.6illustrates an example of system ofFIG.5in action for inspection of cylindrical battery cells according to some aspects of the present disclosure.

Example600includes two snapshots A and B of operation of system500ofFIG.5.

In snapshot A, cylindrical cell602is shown placed inside a holder (e.g., via opening506inFIG.5) within system500(ultrasonic test system500). Two example rollers (may also be referred to as idlers or grippers)604and605are shown that are connected to actuators (mechanical arms)608A and608B, respectively. In one example, actuators608A and608B may be controlled/operated by motor512. Snapshot A also shows two roller (cylindrical) transducers606and607, each being controlled/driven by actuators608C and608D, respectively. Each of transducers606and607may have a wired controller to a controller (e.g., processor110ofFIG.1) via cable610and611. Cable611is shown in snapshot B. Each of transducers606and607may be an array of transducers packaged in a cylindrical unit to perform a single instance of transmission of acoustic signals and reception thereof at every angle of rotation. In this case, at any given angle, an entire vertical or axial slice of battery cell602(from top to bottom of battery cell602) may be acoustically measured in that single instance of transmission and reception of acoustic signals.

In snapshot A, rollers604and605as well as transducers606and607are separated from cylindrical cell602indicating that either battery cell602has just been placed inside system500for inspection or that the inspection of battery cell602is completed and hence may be removed from system500.

In snapshot B, rollers604and605as well as transducers606and607are in contact with cylindrical cell602. While in contact, rollers604and605may rotate cylindrical cell602in theta direction (as indicated by612). With each incremental rotation in theta-direction612, transducers606and607perform an acoustic inspection of cylindrical cell602by transmitting and receiving acoustic signals therethrough. After each rotational measurement to measure a part or every theta position between 0° and 360°, the battery cell602may be translated (moved) in the axial (theta)- or z-direction by some incremental distance. Rotation of cylindrical cell602in theta-direction612continues until the entire axial surface of cylindrical cell602is acoustically scanned.

FIG.7illustrates top and front views of a fixturing mechanism for cylindrical cells used in systems ofFIGS.5and6according to some aspects of the present disclosure. In example ofFIG.6, a fixturing mechanism is formed of rollers604and605. In another example, each of rollers604and605may be formed of two cylindrical rollers. This alternative example is shown inFIG.7.FIG.7provides a front view702and a top view704of a fixturing mechanism formed of structure706and structure706on each side of cylindrical cell710(which is the same as cylindrical cell602) to be acoustically inspected in system500.

Shown in top view704, structure706can include two rollers, roller712and roller714. Similarly, structure708can include two rollers, roller716and roller718. The number of rollers in each structure is not limited to two but may be more or less. Structures706and708as well as rollers712,714,716, and718may be made of any known or to be developed material suitable for carrying out acoustic inspection of cylindrical cells such as cylindrical cell710. Furthermore, structures706and708as well as rollers712,714,716, and718may have different shapes, sizes, and/or dimensions.

In one example, fixturing mechanism having structures706and708is such that one of rollers in structures706and708are driven (e.g., via pneumatic actuator(s), one or more motor(s)) to turn cylindrical cell710when structures706and708come into contact with cylindrical cell710(e.g., as discussed with reference toFIG.6). For instance, roller716may be driven (e.g., using pneumatic actuator(s), one or more motor(s)). As roller716is driven to rotate cylindrical cell710, other rollers (e.g., rollers712,714, and716, which are not driven by any actuator) also rotate in sync with roller716to rotate cylindrical cell710to be acoustically inspected by transducers606and607, as described with reference toFIG.6.

FIG.8is a flowchart of an example method of placing battery cells inside a fixturing mechanism according to some aspects of the present disclosure. Steps ofFIG.6may be implemented by processor110ofFIGS.1and2. As may be evident to those having ordinary skill in the art, processor110may execute computer-readable instructions, such that processor110can send commands to one or more components of ultrasonic test system to carry out the steps described below.

At block802, processor110may send a command to an electronically controlled arm (movable arm) of an ultrasonic test system (e.g., ultrasonic test system432) to select a battery cell from a production line in a battery manufacturing facility for acoustic inspection (acoustic measurements). In one example, an ultrasonic test system may be installed on one or more production lines of the battery manufacturing facility. The type of the ultrasonic test system installed on each line may vary depending on the type of battery cells to be acoustically measured. For instance, ultrasonic test system432may be installed on a production line that produces pouch cells while ultrasonic test system500may be installed on a production line that produces cylindrical cells.

At block804, processor110may send a command to open Fixture within ultrasonic test system for placement of a selected battery cell inside the Fixture (e.g., as described with reference toFIGS.3A-DandFIGS.4A-C) for acoustic inspection. In example of a cylindrical cell, opening a Fixture may entail moving transducers606and607as well as rollers604and605(or structures706and708ofFIG.7) into an open position for cylindrical cell710to be placed in the middle thereof, as described with reference toFIGS.6and7(e.g., position A inFIG.6).

At block806, processor110may send a command to close the Fixture once the selected battery cell is placed therein (e.g., as described with reference toFIGS.3A-DandFIGS.4A-C) for acoustic inspection. In example of a cylindrical cell, closing a Fixture may entail moving transducers606and607as well as rollers604and605(or structures706and708ofFIG.7) to come into contact with cylindrical cell710(e.g., position B inFIG.6).

At block808, processor110may send a command to place the closed Fixture (with battery cell therein) inside ultrasonic test system for acoustic inspection. For instance, this may be performed by moving moving mechanism430into ultrasonic test systems432as shown inFIG.4C, by closing transducers606/607and rollers604/605ofFIG.6(or structures706and708ofFIG.7), etc.

Example embodiments of various Fixtures for acoustic inspection of different types of battery cells (e.g., prismatic cells, pouch cells, cylindrical cells, etc.)

FIG.9shows an example computing system which can be, for example any computing device that can implement components of the system according to some aspects of the present disclsoure.FIG.9shows an example of computing system900, which can be, for example, ultrasonic pulser/receiver108, processor110, a controller for automating loading of cells into example Fixtures described above with reference toFIGS.3-8, etc.) In particular,FIG.9illustrates an example of computing system900, which can be for example any computing device making up internal computing system, a remote computing system, or any component thereof in which the components of the system are in communication with each other using connection902. Connection902can be a physical connection using a bus, or a direct connection into processor904, such as in a chipset architecture. Connection902can also be a virtual connection, networked connection, or logical connection.

Example computing system900includes at least one processing unit (CPU or processor)904that uses connection902to couple various system components including system memory908, such as read-only memory (ROM)910and random access memory (RAM)912to processor904. Computing system900can include a cache of high-speed memory (cache906) connected directly with, in close proximity to, or integrated as part of processor904.

Processor90404can include any general purpose processor and a hardware service or software service, such as service1916, service2918, and service3920stored in storage device914, configured to control processor904as well as a special-purpose processor where software instructions are incorporated into the actual processor design. Processor904may essentially be a completely self-contained computing system, containing multiple cores or processors, a bus, memory controller, cache, etc. A multi-core processor may be symmetric or asymmetric.

To enable user interaction, computing system900includes an input device926, which can represent any number of input mechanisms, such as a microphone for speech, a touch-sensitive screen for gesture or graphical input, keyboard, mouse, motion input, speech, etc. Computing system900can also include output device92222, which can be one or more of a number of output mechanisms known to those of skill in the art. In some instances, multimodal systems can enable a user to provide multiple types of input/output to communicate with computing system900. Computing system900can include communication interface924, which can generally govern and manage the user input and system output. There is no restriction on operating on any particular hardware arrangement, and therefore the basic features here may easily be substituted for improved hardware or firmware arrangements as they are developed.

Storage device914can include software services, servers, services, etc., that when the code that defines such software is executed by processor90404, it causes the system to perform a function. In some embodiments, a hardware service that performs a particular function can include the software component stored in a computer-readable medium in connection with the necessary hardware components, such as processor904, connection902, output device922, etc., to carry out the function.