Temperature testing apparatus and system for testing battery cells and related methods

Abstract

The invention relates to a temperature testing device and system for testing a battery cell and a related method. In some embodiments, the temperature testing devices each include a pair of spaced apart pressure plate, test plate, and pressure clamp. The test board may include a working surface having a plurality of recesses facing a face of the battery cell to be tested, a temperature sensor in each of the plurality of recesses, and an electronic circuit in operative communication with each of the temperature sensors. In some embodiments, the pressure clamp is a constant pressure mechanism. In some embodiments, the pressure clamp is a constant gap pressure mechanism. The invention further discloses a system comprising the temperature testing device and a testing method using the temperature testing device.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Provisional Patent Application Serial No. 63 / 526,716, filed on July 14, 2023, entitled “Temperature Testing Apparatuses and Systems for Testing Battery Cells and Related Methods,” which is incorporated herein by reference in its entirety for all purposes.

[0003] field

[0004] The present disclosure generally relates to the field of temperature testing of battery cells. Specifically, the present disclosure relates to a temperature testing device and system for testing battery cells and related methods. background

[0006] Generally, there are two conventional methods for measuring the temperature of a single battery cell. One is to use a thermal imager to detect the surface temperature of the cell by detecting infrared radiation emitted from the cell, which is displayed on a thermal imaging display in one or more colors, with different colors representing different temperatures. Another conventional method is to use thermal silicone to stick a thermocouple to the cell, and then use a data acquisition instrument and a display to collect and display the temperature data collected via the thermocouple, respectively.

[0007] With a thermal imager, temperature cannot be measured when something blocks the thermal imager from directly viewing the portion of the cell where temperature data is needed. In cell testing involving the use of a pressure fixture to maintain pressure within the battery cell, opposing faces of the battery cell are secured in the pressure fixture and pressurized by the pressure fixture in a direction along the internal stacking axis of the cell. As a result, portions of the pressure fixture block the thermal imager from detecting infrared radiation across the cell surface, where temperature data is most critical.

[0008] With regard to thermocouples in the context of cell testing using a pressure fixture, only the temperature of the outer edge of a battery cell can be detected. This is because if a thermocouple is affixed to the surface of a cell engaged by a pressure fixture, the thermocouple will pierce that surface and damage the cell. Therefore, a thermocouple cannot detect the temperature of the surface of a battery cell clamped in a pressure fixture. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] For the purpose of illustration, the accompanying drawings show aspects of one or more embodiments of the present disclosure. It should be understood, however, that the scope of the present disclosure is not limited to the precise arrangements and instrumentalities shown in the accompanying drawings, in which:

[0011] Figure 1is an exploded view of an exemplary temperature testing device made according to aspects of the present disclosure;

[0012] Figure 2 is an exploded view of another exemplary temperature testing device made according to aspects of the present disclosure;

[0013] Figure 3A is a cross-sectional view of an example test plate of the present disclosure engaged with a battery cell;

[0014] Figure 3B yes Figure 3A an exploded cross-sectional view of an example test board; and

[0015] Figure 4 It is shown that the invention is manufactured according to the present disclosure and includes Figure 1 and Figure 2 Diagram of an example temperature testing system and testing ecosystem for an example temperature testing apparatus of any of. Detailed Description

[0017] The entire content of the appended claims is incorporated into this Detailed Description section as if originally presented herein.

[0018] In some aspects, the present disclosure relates to a temperature test board (hereinafter referred to as a "test board"), which is used to obtain the temperature across the surface of a device under test (DUT) such as a battery cell (hereinafter referred to as a "cell"). As discussed in the background section above, single cell testing can involve monitoring the temperature of the cell during testing (e.g., charge-discharge cycle testing). However, in some testing scenarios, such as testing when the cell is clamped in a pressure fixture, it is not possible to use a thermal imager or a thermocouple affixed to the cell in a conventional manner. The test board of the present disclosure provides a way to measure the temperature of as many surface portions of the battery cell as needed or desired to accommodate testing and temperature data acquisition.

[0019] In some embodiments, the test board of the present disclosure includes a body having a working surface, which will face the face of the DUT when the test board is engaged with the DUT for testing. The working surface includes a plurality of recesses, each of which contains a temperature sensor, such as a negative temperature coefficient (NTC) thermistor, etc. The recesses and corresponding temperature sensors can be arranged in any suitable pattern, such as a regular rectangular array, a circular array, or a non-standard arrangement, such as an arrangement that conforms to the irregular shape of the DUT. The spacing between adjacent recesses / temperature sensor pairs can be any spacing required for a particular type of test. For example, in the context of a rectangular array, the spacing can be the same along two orthogonal axes of the array, can be different between two orthogonal axes, or can vary along one or two orthogonal axes, or any logical combination thereof. Examples of circular arrays include circular arrays based on concentric rings of recesses / temperature sensors and circular arrays based on orthogonal axes, etc. Basically, there is no restriction on the arrangement of recesses and temperature sensors, as long as they provide the desired / necessary results.

[0020] Each temperature sensor is electrically connected to a suitable circuit that makes the sensor operable. In some embodiments, a portion of this circuit is contained in a flexible printed circuit (FPC) located at a relative position of the working surface of the test board. In some such embodiments, the test board may include a rigid panel fixed to the FPC. Depending on the structure, the rigid panel may include a recess or a through hole, the recess or through hole containing the temperature sensor and positioned one-to-one aligned with the electrical sensor contacts on the FPC, and the electrical sensor contacts are electrically connected to the temperature sensor located in the recess or through hole of the rigid panel. In one example, the rigid panel is composed of a printed circuit board (PCB), and the printed circuit board (PCB) has a thickness that can accommodate the selected temperature sensor so that the sensor is recessed or flush with the working surface of the test board. In some embodiments, it is desirable that the rigid panel is flame retardant and / or has a high dielectric constant to be used as an electrical insulator. Examples of other suitable materials include, but are not limited to, certain polymers and composite materials, etc. In some embodiments, the sensor is recessed, for example, 0.5 mm or larger or smaller. Depending on the type of sensor used, the PCB may include electrical contacts for docking with the electrical contacts of the FPC. If through holes are provided in the rigid panel, the temperature sensor can make direct electrical contact with the electrical contacts on the FPC.

[0021] The following table presents some example dimensions of semiconductor-based NTC sensors. The numbers in the first column are four-digit codes from the Electronic Industries Association (EIA) based on the planar area dimensions of the sensor in inches. The numbers in the second column are four-digit EIA codes based on the sensor dimensions in millimeters. For example, the code "0402" in column 1 represents a sensor nominally 0.04 inches x 0.02 inches, while the corresponding code "1005" in column 2 represents the same sensor as 1.0 mm x 0.5 mm. Any of these sensor sizes may be used.

[0022]

[0023] The FPC may include an external contact area and a lead-out area, which respectively contain external electrical contacts for connecting to an additional circuit (e.g., an analog-to-digital converter, a signal conditioning circuit, a microprocessor, a memory, etc.) via an interface and an electrical lead-out conductor for electrically connecting the electrical sensor contacts and the external electrical contacts to each other. The rigid panel and the FPC may be fastened together using any suitable means, such as adhesive bonding, mechanical connectors (e.g., threaded fasteners, interference fit components, clamps, friction fits, etc.) and welding, etc., and any suitable combination thereof. The construction and manufacture of the FPC are well known in the art.

[0024] The temperature sensor may be positioned in the recess in any suitable manner. Because the goal of the test board is to provide as uniform a contact as possible with the face of the DUT, it is generally desirable that the temperature sensor be as flush or nearly flush with the working face of the test board as possible. In some embodiments, the test board is used with a thermally conductive gel deployed between the working face of the test board and the tested face of the DUT. Typically, such a gel is incompressible so that even if the temperature sensor is slightly recessed relative to the working face of the test board, a thermally conductive gel may be provided to fill the gap so as to provide uniform pressure across the entire working face of the test board during testing under the influence of pressure. In this case, the rigid panel and the FPC are designed to withstand at least the maximum pressure that may occur during testing, and the thermal sensors are securely mounted within the recess so that they may also withstand a share of the pressure load.

[0025] In some embodiments, the test board of the present disclosure may have a pair of working surfaces located on opposite sides of the test board and corresponding multiple recesses and temperature sensors. For convenience, such embodiments may be referred to as a "double-sided" test board. In an example, the double-sided test board may be located between a pair of DUTs (such as a pair of battery soft-pack cells). In this way, temperature data of the two DUTs in the pair can be obtained. As an example, the double-sided test board may include two rigid boards, each of which is the same or similar to the rigid boards discussed above, and the rigid boards clamp an FPC that provides electrical connections to the temperature sensors on both sides of the double-sided test board.

[0026] In some aspects, the present disclosure relates to a temperature test device for testing a cell, such as a pouch cell containing a lithium (Li)-based electrochemistry, such as a Li metal (plating type Li metal anode) electrochemistry or a Li ion (intercalation type Li anode) electrochemistry with any one or more suitable types of electrolytes (e.g., liquid electrolytes, gel electrolytes, or solid electrolytes). Electrochemistry based on cations other than Li cations (such as sodium cations, potassium cations, and sulfur cations, etc.) is included within the scope of the present disclosure, as the type of DUT is not a limiting factor.

[0027] In some embodiments, the temperature testing device includes a pressure fixture that holds the battery cells under pressure in the stacking direction of the battery cells during testing (e.g., charge and discharge cycle testing). Here, the stacking direction is the direction in which internal components such as anodes, cathodes, separators, etc. are stacked on each other to form a battery cell. When provided, the pressure fixture may include a pair of pressure plates that apply pressure to one or more batteries captured between the pressure plates during testing and / or resist pressure from the one or more batteries. During the test, also captured between the pressure plates are one or more test plates manufactured according to the present disclosure, such as any of the test plates discussed above. If more than one battery cell is tested, each pair of adjacent batteries can be separated by one test plate (e.g., a double-sided test plate) or two test plates (e.g., a single-sided test plate, whose working surface faces the corresponding corresponding batteries in two adjacent batteries). The pressure plates are designed and constructed to be at least sufficiently rigid so that they provide highly uniform pressure on the surface of the pressure plates.

[0028] If provided, the pressure fixture also includes a pressure mechanism that can be controlled and / or set to provide a desired pressure or pressure distribution during testing. Pressure mechanisms for cell test pressure fixtures are known. However, exemplary pressure mechanisms include spring-type mechanisms (see, e.g., Figure 1 ), hydraulic type mechanisms and screw type mechanisms, etc. Basically, the type of pressure mechanism provided can be any suitable type for the test performed with the temperature testing device.

[0029] Example Embodiments

[0030] Figure 1 An example test system including a temperature test device 100 of the present disclosure and a single battery cell 104 is shown, showing the overall arrangement of the main elements of the temperature test device for acquiring temperature data across one face of the battery cell during a test (such as a charge and discharge cycle test). In this embodiment, the main elements include a pair of pressure plates 108, 112, a rigid panel 116, and an FPC 120. Those skilled in the art will readily appreciate that Figure 1 The elements of the temperature test device 100 are shown broken down along the cell stacking axis A, but during testing, all gaps shown between the pressure plates 108, 112, the battery cells 104, the rigid panel 116, and the FPC 120 will be eliminated so that the adjacent elements of these elements will be firmly in contact with each other. The rigid panel 116 may include a through hole 124, which includes a temperature sensor 128 and is aligned one-to-one with an electrical sensor contact 132 on the FPC 120, and the electrical sensor contact 132 is electrically connected to the temperature sensor located in the through hole of the rigid panel (only a few of each of the through hole, temperature sensor, and electrical sensor contact are marked to avoid clutter). The rigid panel 116 with the through hole 124, the FPC 120 with the electrical sensor contact 132, and the temperature sensor 128 together form a test board 136. In particular, with respect to the rigid panel 116 and the FPC 120 of the test board 136, as described above, they can be fixed together so that the test board is an integral element. The FPC 120 includes a lead-out region 140 containing electrical lead-out conductors (not shown) for electrically connecting the electrical sensor contacts 132 and external electrical contacts (not shown) to each other.

[0031] In this example, pressure is induced in the element between the pressure plates 108, 112 via four threaded spring screws 144 (threads not shown) as part of a constant pressure mechanism 148. By engaging the threaded spring screws 144 to the lower portion (reference Figure 1 ) into four corresponding threaded openings 152 in pressure plate 112 and tightening the spring screws to the required / desired degree to introduce appropriate pressure into the component stack between pressure plates 108, 112 to introduce pressure into battery cell 104. As will be readily appreciated by those skilled in the art, the amount of pressure introduced into battery cell 104 is controlled by the amount the springs (not separately labeled) are compressed by the screws, and the pressure introduced remains largely constant even as the cell changes thickness during charge and discharge as the anodes (not shown) within the cell plates and strips, respectively, change thickness, such as occurs in metal anode cells, such as lithium metal cells. Figure 1Other aspects of the temperature testing device 100 may be the same or similar to those described above and / or as captured in the appended claims.

[0032] Figure 2 Another example testing system including a temperature testing apparatus 200 of the present disclosure and a single battery cell 204 is shown, showing the general arrangement of the main elements of the temperature testing apparatus for acquiring temperature data across one face of a battery cell during a test, such as a charge and discharge cycle test. Figure 1 and Figure 2 Similar parts are represented by the same last two digits. Figure 1 and Figure 2 The main difference between the temperature test devices is that Figure 2 The temperature test device 200 does not include Figure 1 The constant pressure mechanism 148 exists in Figure 2 The battery cell 204 is greater than Figure 1 The battery cell 104, and Figure 2 The FPC 220 has relative Figure 1 The lead-out portion 140 is configured and positioned differently from the lead-out portion 240 .

[0033] In this embodiment, the main components include a pair of pressure plates 208, 212, a rigid panel 216 and an FPC 220. Those skilled in the art will readily appreciate that Figure 2 The components of the temperature test device 200 are shown in exploded form, but during testing, all gaps between the pressure plates 208, 212, the battery cells 204, the rigid panel 216, and the FPC 220 will be eliminated so that the adjacent components of these components will be firmly in contact with each other. The rigid panel 216 can include a through hole 224, which contains a temperature sensor 228 and is positioned in a one-to-one registration with an electrical sensor contact 232 on the FPC 220, and the electrical sensor contact 232 is electrically connected to the temperature sensor located in the through hole of the rigid panel (only two of each of the through hole, temperature sensor, and electrical sensor contact are marked to avoid clutter). The rigid panel 216 with the through hole 224, the FPC 220 with the electrical sensor contact 232, and the temperature sensor 228 together form a test board 236. In particular, with respect to the rigid panel 216 and the FPC 220 of the test board 236, as described above, they can be fixed together so that the test board is an integral component. The lead-out portion 240 of the FPC 220 includes an electrical lead-out conductor (not shown) for electrically connecting the electrical sensor contact 232 and an external electrical contact (not shown) to each other.

[0034] In this example, twelve threaded screws 244 of a constant gap pressure mechanism 248 are engaged to the lower portion (refer to Figure 2) in twelve corresponding threaded openings 252 in pressure plates 212 and tightening the screws to the required / desired degree to introduce appropriate pressure in the component stack between the pressure plates, thereby introducing pressure in the components between pressure plates 208, 212. As will be readily appreciated by those skilled in the art, the amount of pressure introduced into the battery cell 204 is controlled by adjusting the threaded screws 244 so that a desired gap exists between the test plate 236 and the pressure plate 208 on the opposite side of the battery cell. Because the gap remains constant, the pressure introduced will also change as the battery cell 204 changes thickness during charging and discharging of the battery cell plates and anodes (not shown) within the strips, respectively, such as occurs in metal anode cells (e.g., lithium metal cells). Not specifically described Figure 2 Other aspects of the temperature testing device 200 may be the same or similar to those described above and / or as captured in the appended claims.

[0035] In an exemplary embodiment of a test board 236 manufactured according to the present disclosure, the rigid panel 216 includes a PCB, and the temperature sensor 228 includes an NTC thermistor. The PCB includes an 8x 64 array of through holes 224 and NTC thermistors contained therein, for a total of 512 NTC thermistors. The thickness of the PCB is only slightly greater than the thickness of each NTC thermistor, and the size of each through hole 224 is slightly greater than the size of each NTC thermistor. This structure enables the NTC thermistor to detect the surface temperature of the battery cell 204 without directly contacting the surface of the battery cell. If the test situation permits, a thermally conductive gel can be used.

[0036] The FPC 220 provides a backplane mounted to the PCB. The FPC includes an 8x 64 array of electrical contacts 232 to match an 8x 64 array of NTC thermistors. In this example, the FPC 220 also includes an A / D sampling integrated circuit (IC) chip (not shown) for each 16 NTC thermistors, for a total of 32 IC chips for the entire 512 NTC thermistors. Including the IC chips directly on the FPC reduces interference and noise in the electronic circuits that collect temperature data from the NTC thermistors.

[0037] Figure 3A and Figure 3B An example test board 336 of the present disclosure is shown, which may be used to Figure 1 and Figure 2 Any one of the test boards 136, 236. Figure 1 , Figure 2 , Figure 3A and Figure 3B Similar parts are represented by the same last two digits. Figure 3A and Figure 3BAs shown, this embodiment has a sensor 328 located in a through hole 324 in a rigid panel 316 (e.g., PCB, among other possibilities) such that the uppermost portion of the sensor (reference Figure 3A ) surface from the upper side of the rigid panel facing the battery cell 304 (reference Figure 3A ) The surface is recessed by a distance D of about 0.5 mm. FPC 320 and sensor 328 may be any suitable FPC and sensor, such as those described herein. Figure 3B As shown, sensors 328 may be attached to FPC 320, such as by soldering them to electrical contacts (not shown). Figure 3A and Figure 3B Other aspects of the example test board 336 can be the same or similar to such aspects mentioned elsewhere in this disclosure.

[0038] Figure 4 An exemplary temperature testing system 400 and an exemplary overall testing ecosystem 404 are shown, which include the temperature testing apparatus of the present disclosure, such as discussed above and in Figure 1 and Figure 2 Any one of the temperature test devices 100, 200 shown in FIG. Figure 4 In the example temperature testing system 400, the external electrical contacts (not shown) of the external contact area 140 of the FPC 120 of the test board 136 (here the combination of the FPC 120+rigid panel 116 as described above) are electrically connected to the temperature testing management system 408, which in this example includes circuits for operating the temperature sensors on the test board 136 and collecting temperature data from the temperature sensors.

[0039] Once the temperature data is collected, a temperature distribution image 412 may be displayed on a suitable display 416 using suitable imaging software. In some embodiments, the imaging software may be configured to provide a plot of different colors, which may be similar to the multi-color image output by an infrared thermal imager. For example, red may indicate the hottest areas, blue may indicate the coldest areas, yellow may indicate areas with intermediate temperatures, and mixtures of adjacent colors in these colors (blue+yellow and yellow+red) may represent areas with temperatures between the temperatures of the two colors. Figure 4 In the example temperature distribution image 412 of FIG. 4 , the red hot spot 420 is surrounded by a yellow intermediate region 424, and the yellow intermediate region is surrounded by a blue cooler region 428. Although the temperature sensors are located at discrete locations within their arrangement on the test board 136, the imaging software may include an algorithm for interpolating temperature values ​​between any two actual readings in order to create a visually continuous image that includes a color blend or other gradient representing the interpolated temperatures between the actual measurement locations.

[0040] The example test ecosystem 404 may optionally include a local test computing system 432 that includes hardware and software for controlling overall testing of the battery cell 104, including temperature testing via the temperature testing system 400 and testing of the battery cell that may cause temperature changes to be monitored by the temperature testing system, such as life cycle testing and / or testing involving severe operating conditions. It should be noted that the electrical connection between the local test computing system 432 and the battery cell 104 (e.g., via the battery cell's tabs 436, 440) is not Figure 4 , but may be the same or similar to such connections known in the cell testing art. Also not shown are other components that may be used during testing, such as, but not limited to, test chambers, pressure sensors, environmental controllers (heaters, coolers, fans, etc.) and corresponding systems, etc. Each of these components, as needed or provided, may be the same or similar to such components known in the cell testing art.

[0041] exist Figure 4 In the example of , the test ecosystem 404 may also include an enterprise computing system 444 that collects and stores test data and may include algorithms for using the test data as needed, such as designing a battery management system, etc. Figure 4 Other aspects of the temperature testing system 400 and the testing ecosystem 404 may be the same or similar to those described above and / or as captured in the appended claims.

[0042] Various modifications and additions may be made without departing from the spirit and scope of the present disclosure. The features of each of the various embodiments described above may be appropriately combined with the features of the other described embodiments so as to provide a variety of feature combinations in associated new embodiments. In addition, although the foregoing describes a plurality of separate embodiments, the content described herein merely illustrates the application of the principles of the present invention. In addition, although the specific methods herein may be illustrated and / or described as being performed in a particular order, it is within the technical scope of the art that the sequencing is highly variable to implement aspects of the present disclosure. Accordingly, this description is meant to be taken only as an example and does not otherwise limit the scope of the present invention.

[0043] Exemplary embodiments have been disclosed above and shown in the accompanying drawings. Those skilled in the art will appreciate that various changes, omissions and additions may be made to the specific disclosure herein without departing from the spirit and scope of the present invention.

Claims

1. A test board for testing a device under test (DUT) having spaced-apart faces in a pressure fixture, the pressure fixture applying pressure to the DUT and / or resisting pressure from the DUT during testing, the pressure fixture comprising a pair of spaced-apart pressure plates, the test board comprising: a body designed and configured to be positioned between the DUT and one of the pressure plates when the DUT is pressurized within the pressure fixture, the body comprising: a working surface that faces one of the spaced-apart surfaces of the battery cell during testing; a plurality of recesses formed in and distributed across the working surface; and a temperature sensor located in each of the plurality of recesses; and Electronic circuitry is in operable communication with each of the temperature sensors. 2 . The test board according to claim 1 , wherein each of the temperature sensors is a negative temperature coefficient thermistor. 3 . The test plate of claim 1 , wherein each temperature sensor has a front surface facing the battery cell during testing, wherein the front surface is recessed within a recess accommodating the temperature sensor.

4. The test board according to claim 3, wherein: During testing, thermal gel is located between each temperature sensor and a spaced-apart face of the DUT proximate the test board. 5 . The test board according to claim 1 , wherein the plurality of recesses are arranged in an array on the working surface of the test board. 6 . The test board according to claim 1 , wherein the test board comprises 30 or more of the recesses and 30 or more of the temperature sensors. 7 . The test board according to claim 6 , wherein the test board comprises 100 or more of the recesses and 100 or more of the temperature sensors. 8 . The test board of claim 1 , wherein the temperature sensors are functionally grouped into a plurality of groups, and the electronic circuit comprises a circuit for processing temperature sensor signals from the temperature sensors group by group.

9. The test board of claim 8, wherein the circuitry for processing temperature sensor signals comprises a plurality of analog-to-digital (A / D) converters.

10. The test board according to claim 9, wherein: The body includes a flexible printed circuit (FPC), and the A / D converter is located on the FPC. 11 . The test board of claim 10 , wherein the body further comprises a rigid panel fixed to the FPC, wherein the recess is formed in the rigid panel.

12. The test board of claim 11, wherein the rigid panel comprises a printed circuit board (PCB). 13 . The test board of claim 12 , wherein the PCB comprises the recess and an electrical contact in a bottom of the recess, the electrical contact electrically contacting the thermal sensor.

14. The test board according to claim 1, wherein: The test board includes a rigid panel containing a plurality of through holes providing the plurality of recesses. 15 . The test board of claim 14 , wherein the test board further comprises a back plate, the temperature sensor being fixed to the back plate.

16. The test board of claim 15, wherein the backplane comprises a flexible printed circuit (FPC) containing electrical contacts in electrical communication with the plurality of sensors.

17. The test board according to claim 1, wherein: The body includes a pair of spaced apart working surfaces, each working surface having a plurality of recesses formed therein and distributed across the working surface.

18. The test board according to claim 17, wherein: The body includes a back plate and a pair of rigid panels that sandwich the back plate and define the plurality of recesses.

19. The test board of claim 18, wherein the backplane comprises a flexible printed circuit (FPC) containing electrical contacts in electrical communication with the plurality of sensors.

20. The test board of any one of claims 16 and 19, wherein the FPC comprises an external contact area including a plurality of external electrical contacts in electrical communication with corresponding respective ones of the electrical contacts that are in electrical contact with the plurality of sensors.

21. The test board of claim 20, wherein the FPC includes a lead-out region between each working surface present and the external contact region, the lead-out region containing electrical conductors that operably connect the plurality of external electrical contacts with electrical contacts that are in electrical contact with the plurality of sensors.

22. An apparatus for testing a device under test (DUT) having spaced-apart faces, the apparatus comprising: a pressure fixture including a pair of pressure plates and a pressurizing mechanism that causes the pressure plates to induce pressure within the DUT when the DUT is present between the pressure plates for testing, the spaced-apart faces facing a corresponding one of the pressure plates during the testing; A test panel according to any one of claims 1 to 21.

23. The apparatus of claim 22, wherein the DUT comprises a battery cell.

24. The device according to claim 22, wherein: During testing, thermal gel is located between each temperature sensor and a spaced-apart face of the DUT proximate the test board.

25. The apparatus of claim 22, wherein the temperature sensors are functionally grouped into a plurality of groups, and the electronic circuit comprises circuitry for processing temperature sensor signals from the temperature sensors group by group.

26. A temperature tester for testing a device under test (DUT) having spaced-apart faces in a pressure fixture, the pressure fixture comprising a pair of pressure plates and a pressure mechanism that causes the pressure plates to induce pressure within the DUT when the DUT is present between the pressure plates for testing, the temperature tester comprising: A test panel according to any one of claims 1 to 21; and Electronic circuitry is in operable communication with each of the temperature sensors.

27. The temperature tester of claim 26, wherein the DUT comprises a battery cell.

28. The temperature tester according to claim 26, wherein: During testing, thermal gel is located between each temperature sensor and a spaced-apart face of the DUT proximate the test board.

29. The temperature tester of claim 26, wherein the temperature sensors are functionally grouped into a plurality of groups, and the electronic circuit includes circuitry for processing temperature sensor signals from the temperature sensors group by group.

30. A method of testing a battery cell having spaced-apart faces, the method comprising: placing the battery cell in a pressurized test fixture between a pair of pressure plates such that one of the spaced-apart faces faces a working face of a pressure plate between the pressure plates to form a test stack having a stacking direction, wherein the test plates include a plurality of recesses, each recess including a temperature sensor; causing the pressure plate to introduce pressure into the test stack in a direction parallel to the stacking direction; electrically cycling the battery cells; and The temperature data of the battery cell is collected via the temperature sensor.

31. The method of claim 30, wherein each of the temperature sensors is a negative temperature coefficient type temperature sensor.

32. The method of claim 30, wherein each temperature sensor has a front surface that faces the battery cell during testing, wherein the front surface is recessed into a recess containing the temperature sensor.

33. The method of claim 30, wherein: During testing, thermal gel is located between each temperature sensor and the spaced-apart face of the battery cell proximate the test plate.

34. The method of claim 30, wherein the plurality of recesses are arranged in an array on the working surface of the test plate.

35. A method according to claim 30 or claim 34, wherein the test plate comprises 30 or more said recesses.

36. The method of claim 30, wherein the temperature sensors are functionally grouped into a plurality of groups, and the electronic circuit includes circuitry for processing temperature sensor signals from the temperature sensors group by group.

37. The method of claim 30, wherein: The test board includes a rigid panel containing a plurality of through holes providing the plurality of recesses.

38. The method of claim 37, wherein: The test board also includes a back plate to which the temperature sensor is fixed.

39. The method of claim 38, wherein the backplane comprises a flexible printed circuit.

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