Magnetic force dilatometer for measuring the dilation of a single electrode

Abstract

A dilatometer for measuring battery dilation, comprising: a battery cell having a first electrode and a second electrode; an internal magnetic sensing element; and a magnetic force sensor. The internal magnetic sensing element is configured to move in response to expansion of the first electrode during dilation of the battery cell and to remain stationary in response to expansion of the second electrode. The magnetic force sensor is stationary relative to the battery cell and configured to detect a change in magnetic force between the internal magnetic sensing element and the magnetic force sensor. A controller is configured to measure the dilation of the first electrode independently of the dilation of the second electrode based on the change in magnetic force strength between the internal magnetic sensing element and the magnetic force sensor.

Description

INITIATIONThe information in this section is intended to generally illustrate the context of the disclosure. Work of the present inventors, insofar as described in this section, as well as aspects of the description that may not be prior art at the time of filing, are neither expressly nor silently admitted as prior art against the present disclosure.The present disclosure relates to systems and methods for measuring battery dilation, and more particularly to systems and methods for measuring dilation of a single battery electrode.A battery pack includes one or more battery modules each including a plurality of battery cells. The battery cells undergo dilation when the battery is charged and discharged. During charging and discharging of the battery cells, chemical reactions within the battery cells cause the anode or cathode electrodes to expand or enlarge or contract. Monitoring dilation of the battery cells is useful to avoid drying out of the electrodes, improve battery cell life, develop battery cells, estimate energy density, and / or design battery modules and battery packs.SUMMARYThe present disclosure provides a dilatometer for measuring battery dilation, including: a battery cell having a first electrode and a second electrode; an internal magnetic sensor element; and a magnetic force sensor. The internal magnetic sensor element is configured to move in response to expansion of the first electrode and remain stationary during dilation of the battery cell in response to expansion of the second electrode. The magnetic force sensor is stationary relative to the battery cell and is configured to sense a change in magnetic force between the internal magnetic sensor element and the magnetic force sensor. A controller is configured to measure the dilation of the first electrode independently of the dilation of the second electrode based on the change in the strength of magnetic force between the internal magnetic sensor element and the magnetic force sensor.In further features, the internal magnetic sensor element is located between the first and second electrodes.In further features, the battery cell includes a separator between the first electrode and the second electrode, wherein the magnetic sensor element is located between a first portion of the separator and a second portion of the separator.In further features, the first electrode is closer to the magnetic force sensor than the second electrode.In further features, the magnetic sensor element is configured such that ions can pass through the magnetic sensor element to move between the first electrode and the second electrode.In further features, the magnetic sensor element is porous and configured such that an electrolyte of the battery cell can flow through the magnetic sensor element.In further features, the magnetic sensor element is coated with a non-conductive material.In further features, a carrier is located between the first electrode and the second electrode, the carrier carrying the first electrode and configured to allow ions to pass through the carrier to move between the first electrode and the second electrode.In further features, the magnetic sensor element is disposed adjacent the first electrode and is configured to move away from the magnetic force sensor when the first electrode expands during dilation and remain stationary when the second electrode expands during dilation.In further features, the magnetic force sensor further comprises a load sensor, a strain gauge, a pressure sensor, or an electromagnetic force recovery sensor.In further features, the battery cell is a pouch or a pouch. Pouch cell.In other features, the battery cell is a prismatic cell.The present disclosure further provides, in various features, a dilatometer for measuring dilation in a coin cell battery. The dilatometer comprises: a housing of the coin cell battery; a first electrode within the housing; a second electrode within the housing; a separator within the housing between the first electrode and the second electrode; an internal magnetic sensor element within the housing configured to move and remain stationary in response to expansion of the first electrode during dilation of the coin cell battery; an external magnet disposed outside the housing and spaced from the housing a certain distance; a sensor configured to measure the strength of the magnetic force between the internal magnetic sensor element and the external magnet; and a controller configured to measure the dilation of the first electrode independently of the dilation of the second electrode based on the change in the strength of the magnetic force measured by the sensor between the external magnet and the internal magnetic sensor element.In further features, the internal magnetic sensor element is located between a first portion of the separator and a second portion of the separator.In further features, a support member is located between a first portion of the separator and a second portion of the separator, the support member supporting the first electrode and configured to allow ions to pass through the support member to move between the first electrode and the second electrode.In further features, the internal magnetic sensor element is disposed adjacent to the first electrode and is configured to move away from the sensor when the first electrode expands during dilation and remain stationary when the second electrode expands during dilation, the internal magnetic sensor element further configured as a spacer between the first electrode and a biasing member.The present disclosure also provides, in various features, a dilatometer for measuring the dilation of a first electrode of a coin cell battery including the first electrode and the second electrode. The dilatometer comprises: a coin holder configured to hold the coin battery; an external magnet disposed adjacent the coin holder and spaced apart from the coin battery seated in the coin holder; a force sensor configured to measure the strength of the magnetic force between the external magnet and an internal magnetic sensing element in the coin battery, the internal magnetic sensing element configured to move in response to expansion of the first electrode and remain stationary in response to expansion of the second electrode during dilation of the coin battery; a translation table configured to support the force sensor; and a controller configured to measure the dilation of the first electrode independently of the dilation of the second electrode based on the change in the strength of the magnetic force measured by the force sensor between the external magnet and the internal magnetic sensor element.In other features, the external magnet is a ball magnet, a hemispherical magnet, or a conical magnet.In further features, the force sensor includes a load cell, a strain gauge, or a pressure sensor.In further features, the coin holder is configured to hold the coin battery during charging and / or discharging of the coin battery. The controller is configured to measure dilation of the first electrode independently of the second electrode during charging and / or discharging of the coin battery.Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.BRIEF DESCRIPTION OF THE DRAWINGSThe present disclosure will become more fully apparent from the detailed description and the accompanying drawings, in which: FIGS. 1A and 1B are side views of an example of a magnetic force dilator (MFD) for measuring dilation of a single electrode of a battery cell according to the present disclosure; FIGS. 2 and 3 are side views of other examples of MFDs for measuring dilation of a single electrode of a battery cell according to the present disclosure; FIGS. 4A and 4B are side views of another example of an MFD for measuring dilation of a single electrode of a battery cell; FIG. 5 is a plan view showing another example of an MFD for measuring dilation of a temperature compensated battery cell according to the present disclosure; FIG. 6 is a side view of the MFD of FIG. 5 ; and FIG. 7 is a side view of the MFD of FIG. 5.In the drawings, reference numerals may be reused to identify similar and / or identical elements.DETAILED DESCRIPTIONBattery cells such as lithium ion batteries (LIBs) undergo reversible and irreversible expansion or dilation during cycle operation. A detailed understanding of the expansion or dilation of battery cells may be used to avoid drying out of the electrodes, improve the life of battery cells, develop battery cells, estimate energy density, and / or design a battery pack. For next generation anode materials, such as silicon, expansion or dilation of the battery cell is a much greater problem because some electrode materials experience a volume change of about 300% during cycle operation.The present disclosure relates to a magnetic force dilator (MFD) configured to measure dilation of battery cells during cycle operation. In commonly assigned U.S. Patent Application No. 18 / 087,452, filed December 22, 2022, entitled "SYSTEMS AND METHODS FOR MEASURING BATTERY DILATION" (systems and methods for measuring dilation of batteries), which is hereby incorporated by reference in its entirety, an MFD is configured to measure dilation of battery cells during cycle operation. Commonly assigned U.S. Patent Application No. 18 / 305,075, filed April 21, 2023, entitled "MAGNETIC FORCE DILATOR WITH TEMPERATURE COMPENSATION" (magnetic force dilator with temperature compensation), is also hereby incorporated by reference in its entirety.An MFD according to the present disclosure is configured to measure dilation of a single electrode of a battery cell independently of dilation of the other electrode of the battery cell. The ability to measure the dilation of individual electrodes improves the overall understanding of the dilation of battery cells. Knowing the dilation rate of a single electrode and the conditions under which the electrode expands will allow advances in battery cell technology.FIGS. 1A and 1B show an MFD 10 for measuring battery dilation. The MFD 10 includes a battery cell 20 (e.g., a lithium ion battery cell). The battery cell 20 includes a housing 22 enclosing one or more sets of first electrodes 24, second electrodes 26, and separators 28. The separators 28 each include a first portion 28A and a second portion 28B. Next to the second electrode 26, a spacer 30 is disposed.A biasing member 32 (e.g., a spring) is disposed between the spacer 30 and an inner surface of the housing 22. The biasing member 32 holds the spacer 30 against the second electrode 26 and is flexible to accommodate movement of the spacer 30 as the first electrode 24 and / or the second electrode 26 expand during dilation.Between the first electrode 24 and the second electrode 26 is a magnetic sensor element 60 which is an internal magnet. The magnetic sensor element 60 (e.g., a permanent magnet, an electromagnet, or a ferromagnetic material) is arranged to move within the housing 22 as the first electrode 24 expands during dilation of the battery cell 20. The magnetic sensor element 60 remains stationary during the individual dilation of the second electrode 26. The magnetic sensor element 60 is located between the first portion 28A and the second portion 28B of the separator. The magnetic sensor element 60 is configured to allow ions to pass through the magnetic sensor element 60 between the first electrode 24 and the second electrode 26. The magnetic sensor element 60 may include, for example, a wire mesh of nickel or steel, or may be otherwise porous to allow electrolyte to flow therethrough. The magnetic sensor element 60 may also be filled with an electrolyte or made ionically conductive in a suitable manner. The magnetic sensor element 60 may be coated with a suitable non-electrically conductive material to isolate the first electrode 24 and the second electrode 26 and thus prevent a short circuit. The magnetic sensor element 60 may be coated with, for example, aluminum oxide or a polymer coating such as polypropylene or polyethylene. The separator 28 is optional, in particular if the magnetic sensor element 60 is provided with a non-conductive coating.The MFD 10 further includes an external magnet 40 disposed outside of the housing 22 of the battery cell 20 and spaced from the housing 22. The external magnet 40 may be a hemispherical magnet, a spherical magnet, a conical magnet, a cylindrical magnet, a square magnet, a rectangular magnet, or any other suitable magnet. The external magnet 40 and the magnetic sensor element 60 are arranged in the magnetic fields of the other.The MFD 10 also includes a sensor 42 configured to measure the strength of the magnetic force between the external magnet 40 and the magnetic sensor element 60. The sensor 42 may be any suitable force sensor, e.g., a load cell sensor, a strain gauge sensor, a pressure sensor, etc. In some applications, the external magnet 40 and the sensor 42 may be replaced with a Hall sensor, a magnetic resistor, a fluxgate sensor, a superconducting quantum interference device (SQUID) sensor, a resonant sensor, an induction magnetometer, a reed contact sensor, a Wiegand wire sensor, or a magnetic force sensor.An optional temperature sensor 46 measures the temperature of a component of the MFD 10 or the ambient temperature of the MFD 10. A controller 50 communicates with the sensor 42 and the temperature sensor 46. the controller 50 is configured to determine the dilation of the first electrode 24 based on changes in the strength of the magnetic force between the external magnet 40 and the magnetic sensor element 60. The controller 50 receives the temperature signal from the temperature sensor 46, and performs temperature correction or compensation of the measured dilation based on the temperature measured by the temperature sensor 46.The change in dilation takes place, for example, in response to the expansion of the first electrode 24 and / or on account of temperature fluctuations during the dilation measurement. The expansion or dilation causes the magnetic sensor element 60 to move relative to the external magnet 40, but the measurement of dilation is affected by temperature. In other words, the measurement of the dilation of the battery cell at a specific temperature is different than the measurement of the dilation of the battery cell at a different temperature. The controller 50 compensates for the dilation measurements based on the measured temperature.In FIG. 1A, the battery cell 20 is shown in an unstretched state with the external magnet 40 disposed at a distance d 1 from the magnetic sensor element 60. The first electrode 24 has a thickness t1. In FIG. 1B, the battery cell 20, in particular the first electrode 24, is illustrated in a stretched state. The thickness of the first electrode 24 increased from t1to t2. As the thickness of the first electrode 24 increases, the magnetic sensor element 60 moves farther from the external magnet 40. In the expanded state of FIG. 1B, the magnetic sensor element 60 is disposed from the external magnet 40 at a distance d 2 larger than the distance d 1. At the distance d 2, the magnetic attraction between the external magnet 40 and the magnetic sensor element 60 is less than at the distance d 1.In some examples, the controller 50 uses one or more formulas relating dilation to load cell measurement and / or temperature. In other examples, the controller 50 includes a memory storing a first calibration table storing dilation as a function of load cell measurement and a second calibration table storing dilation compensation values as a function of temperature. The first calibration table contains the known strength of the magnetic force between the external magnet 40 and the internal magnetic sensor element 60 at different distances d. The second calibration table stores the dilation compensation values at different temperatures. In some examples, the first and second calibration tables are combined into a single table indexed by load cell measurement and the measured temperature and / or strain that is a function of temperature.Based on the first and / or second calibration tables, the controller 50 determines the distance d2between the external magnet 40 and the magnetic sensor element 60 corresponding to the magnetic strength measured by the sensor 42 and compensated based on the measured temperature. The change in the distance (d2-d1) corresponds to the strain (t2-t1) of the first electrode 24.The dilation data may be used for a variety of different purposes. For example, knowing the extent to which the first electrode 24 of the battery cell 20 has expanded after a certain number of charge / discharge cycles and / or under various conditions may be useful for the development of batteries that are less prone to drying out the electrodes and have a longer life. The information may also be used in the construction of the battery cells, the estimation of the energy density, and the development of various battery modules and packs. An exemplary calibration method is discussed in greater detail herein.As shown in FIG. 2, the sensor 42 is disposed between the external magnet 40 and the housing 22. The sensor 42 is in direct contact with the housing 22 and includes a pressure sensor. Referring to FIG. 3, the sensor 42 includes a magnetic sensor. In some examples, the sensor 42 is selected from a group consisting of a Hall sensor, a magneto-resistance sensor, a fluxgate sensor, a superconducting quantum interference device (SQUID) sensor, a resonance sensor, an induction magnetometer, a reed contact sensor, a Wiegand wire sensor, and / or a magnetic force sensor. The sensor 42 is spaced from the housing 22.FIGS. 4A and 4B show another configuration of the MFD 10 according to the present disclosure including a carrier 70. The carrier 70 is a rigid carrier element which is fastened in the battery cell 20 in a suitable manner, such that the carrier 70 remains stationary. The carrier 70 is located between the first electrode 24 and the second electrode 26. The carrier 70 is configured to support the first electrode 24. The first electrode 24 may be directly seated on the carrier 70, or the second portion 28B of the separator may be disposed between the carrier 70 and the first electrode 24. The second electrode 26 is located below the support 70, and the first portion 28A of the separator overlies the second electrode 26.The carrier 70 is made of a suitable material configured to allow ions to pass between the first electrode 24 and the second electrode 26. The carrier 70 may be made of the same material as the magnetic sensor element 60 described above in FIGS. 1A and 1B, for example. However, the carrier 70 is not configured as a sensor element and therefore need not be magnetic. The support 70 may be made of, for example, a suitable glass frit material.In the examples of FIGS. 4A and 4B, the magnetic sensor element 60 sits on the first electrode 24. thus, the magnetic sensor element 60 moves in response to the expansion of the first electrode 24 during the dilation of the battery cell 20. The magnetic sensor element 60 acts as a spacer between the first electrode 24 and the biasing member 32 in the example of FIGS. 4A and 4B.Prior to the expansion of the first electrode 24, the first electrode 24 has a thickness t1and the magnetic sensor element 60 is at a distance d1from the external magnet 40 (FIG. 4A ). In response to the expansion of the first electrode 24, the magnetic sensor element 60 moves to the distance d 2 from the external magnet 40 (FIG. 4B ). The distance d 2 is greater than the distance d 1. The first electrode 24 further increases from the thickness t 1 to the thickness t 2 (FIG. 4B ). The controller 50 receives the distance change from d 1 to d 2 and is configured to measure the extension of the first electrode 24 based on the distance change in the same manner as described above in the description of the configuration of FIGS. 1A and 1B. The configuration of FIGS. 4A and 4B is therefore configured to measure the dilation of the electrode furthest from the outer magnet 40 (i.e., the innermost electrode). The configuration of FIGS. 1A and 1B is configured to measure the dilation of the electrode closest to the external magnet 40 and the housing 22 (i.e., the outermost electrode).In FIGS. 5-7, further examples are shown. In FIG. 5, a sensor 150 is attached to the battery cell holder 114 and configured for temperature measurement. The measured temperature is used to compensate for the measured dilation for temperature variations. In some examples, multiple position values for the same battery cell, different battery cells, or battery cells of different chemistries are set to a predetermined temperature so that the results of the dilatometer measurements can be compared.The sensor 150 may be configured as a strain sensor for measuring strains. Since the strain is a function of temperature, the temperature can be derived from the measured strain. The measured strain may be used directly to compensate for the measured dilation for temperature variations. The measured strain can also be used to determine the temperature, which can then be used to compensate for the measured dilation for temperature fluctuations. The sensor configured as a temperature sensor may alternatively be mounted in a cavity or bore in the battery cell holder 114 and / or another component of the MFD. In some examples, the temperature sensor comprises a thermocouple.In FIGS. 5-7, a dilatometer 110 is configured to measure dilation with temperature compensation of a suitable battery cell when the battery cell is charged and discharged. For example, the dilatometer 110 is configured to measure the dilation of the battery cell 20 of FIGS. 1A, 1B, 2, 3, 4A, and 4B in real time. The dilatometer 110 includes a chassis 112 (e.g., a base plate) and a battery cell holder 114 secured to the chassis 112.The battery cell holder 114 is configured to receive a coin battery or other type of battery cell. For charging and discharging the battery cell 20, wires are connected to the battery cell 20. A translation table 116 is attached to the battery cell holder 114 to support a load cell 120. Load cell 120 may be any suitable load cell, such as a Miniature S-Bear Jr. 2.0 load cell (model LSB201) from Futek Advanced Sensor Technology, Inc. of Irvine, CA. The dilatometer 110 comprises a micrometer 130 for adjusting the vertical height of the translation table 116 and for adjusting the vertical position of the load cell 120 arranged on the translation table 116.A magnet holder 122 is arranged on the load cell 120, which serves to receive the external magnet 40. In this example, the external magnet 40 includes a spherical magnet. As can be appreciated, the magnet holder 122 may be configured to hold external magnets having other suitable shapes. The battery cell 20 is held in the battery cell holder 114 between the external magnet 40 and a compression member 124 that holds the battery cell 20 in position.Dilatometer 110 may be used to calibrate controller 50 and to generate the calibration tables described above. The calibration tables may be prepared, for example, as follows. By means of the micrometer 130, the slide table 116 is raised, thereby raising the external magnet 40. The slide table 116 is raised until the magnetic strength between the external magnet 40 and the magnetic sensor element 60 measured by the load cell 120 starts to decrease.The magnetic strength increases until the external magnet 40 contacts the housing 22, whereupon the magnetic strength indication begins to decrease. The translation table 116 is adjusted up or down until the force on the load cell 120 is maximized. Once the force on load cell 120 is maximized, controller 50 is configured to begin recording the load cell data at any suitable intervals.For example, the controller 50 may be configured to record one or two measurements per second. The displacement table 116 is then lowered at least three times in 50 μm steps, while recording several values (e.g. 5-10 per adjustment step). The translation table 116 is raised in 50 μm increments back to the origin, recording a plurality of values (e.g., 5-10 per indexing increment). The process may be repeated for other temperatures.After calibration, the dilatometer 110 may be used to measure the dilation of the first electrode 24 of the battery cell 20 or another suitable battery as the battery cell 20 cycles charge and discharge. Leads are connected to dilatometer 110 to cycle battery cell 20. The controller 50 is configured to record data from the load cell 120 in any suitable time increments, e.g., in 5 second increments.The foregoing description is merely illustrative in nature and is not intended to limit the disclosure, its application, or use. The broad teachings of the disclosure may be practiced in a variety of forms. Therefore, although this disclosure includes particular examples, the true scope of the disclosure should not be so limited as other modifications will be apparent upon a study of the drawings, the specification, and the following claims. It should be appreciated that one or more steps within a method may be performed in different order (or simultaneously) without altering the principles of the present disclosure. Although each of the embodiments is described above with certain features, any one or more of those features described with respect to any embodiment of the disclosure may be implemented in any of the other embodiments and / or combined with features of any other embodiment, although that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with each other remain within the scope of this disclosure.Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described with various terms, e.g., "connected," "engaged," "coupled," "adjacent," "next," "on," "over," "under," and "arranged.". When a relationship between first and second elements is not expressly described as "direct" in the above disclosure, this relationship may be a direct relationship in which no other intervening elements are present between the first and second elements, but may also be an indirect relationship in which one or more intervening elements (either spatially or functionally) are present between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be construed as logical (A OR B OR C) using a non-exclusive logical OR, and should not be understood as "at least one of A, at least one of B, and at least one of C.".In the figures, the direction of an arrow, as indicated by the arrow head, generally indicates the flow of information (e.g., data or instructions) of interest for the display. For example, if element A and element B exchange a variety of information, but the information transmitted from element A to element B is relevant for presentation, the arrow may point from element A to element B. This unidirectional arrow does not imply that no further information is transmitted from element B to element A. In addition, element B for information sent from element A to element B may send requests for or acknowledgments for the information to element A.In this application, including the definitions below, the term "module" or the term "controller" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include a module: an application specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores the code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, e.g., in a system-on-chip.The module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces connected to a local area network (LAN), the Internet, a wide area network (WAN), or combinations thereof. The functionality of any module of the present disclosure may be distributed among multiple modules connected via interface circuits. For example, multiple modules may allow load balancing. In another example, a server module (also referred to as a remote or cloud module) may perform some functions on behalf of a client module.The term code as used above may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. The term shared processor circuit ("shared processor circuit") includes a single processor circuit that executes some or all of the code from multiple modules. The term "group processor circuit" includes a processor circuit that, in combination with other processor circuits, executes some or all of the code from one or more modules. References to multiple processor circuits (multiple processor circuits) include multiple processor circuits on discrete chips, multiple processor circuits on a single chip, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the foregoing. The term shared memory circuit ("shared memory circuit") includes a single memory circuit that stores part or all of the code from multiple modules. The term "group memory circuit" includes a memory circuit that, in combination with other memories, stores some or all of the code from one or more modules.The term "memory circuit" is a subset of the term "computer readable medium.". The term "computer-readable medium" as used herein does not include transitory electrical or electromagnetic signals propagating through a medium (e.g., on a carrier wave); the term "computer-readable medium" may therefore be considered tangible / tangible and non-transitory. Non-limiting examples of a non-transitory, tangible computer readable medium include non-transitory memory circuits (e.g., a flash memory circuit, an erasable programmable read only memory circuit, or a mask read only memory circuit), volatile memory circuits (e.g., a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (e.g., an analog or digital magnetic tape or a hard disk drive), and optical storage media (e.g., a CD, a DVD, or a Blu-ray Disc).The apparatus and methods described in this application may be implemented in part or in whole by a special purpose computer formed by configuring a general purpose computer to perform one or more particular functions embodied in computer programs. The above-described function blocks, flowchart components, and other elements serve as software specifications that can be translated into the computer programs by the routine work of an skilled technician or programmer.The computer programs include processor-executable instructions stored on at least one non-transitory, tangible computer-readable medium. The computer programs may also contain or access stored data. The computer programs may include a basic input / output system (BIOS) that interacts with the hardware of the special purpose computer, device drivers that interact with certain devices of the special purpose computer, one or more operating systems, user applications, background services, background applications, etc.The computer programs may include: (i) descriptive text to be parsed, e.g., hypertext markup language (HTML), extensible markup language (XML), or javascript object notation (JSON), (ii) assembler code, (iii) object code generated by a compiler from the source code, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. The source code may be used with only, for example, the syntax of languages such as C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, r, Lisp, Java® Fortran, Perl, Pascal, Curl, OCaml, Javascript® HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Precursor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash® Visual Basic® Lua, MATLAB, SIMULINK, and Python® may be written.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedUS 18 / 087,452

[0028] US 18 / 305,075

[0028]

Claims

A dilatometer for measuring battery dilation, comprising: a battery cell having a first electrode and a second electrode; an internal magnetic sensor element; a magnetic force sensor, the internal magnetic sensor element configured to move during dilation of the battery cell in response to expansion of the first electrode and remain stationary in response to expansion of the second electrode, and the magnetic force sensor is stationary relative to the battery cell, the magnetic force sensor configured to sense a change in magnetic force strength between the internal magnetic sensor element and the magnetic force sensor; and a controller configured to measure dilation of the first electrode independently of dilation of the second electrode based on the change in magnetic force strength between the internal magnetic sensor element and the magnetic force sensor.The dilatometer of claim 1, wherein the internal magnetic sensor element is located between the first electrode and the second electrode.The dilatometer of claim 1, wherein the battery cell further comprises a separator between the first electrode and the second electrode, and the internal magnetic sensor element is between a first portion of the separator and a second portion of the separator.The dilatometer of claim 1, wherein the first electrode is closer to the magnetic force sensor than the second electrode.The dilatometer of claim 1, wherein the internal magnetic sensor element is configured such that ions can pass through the internal magnetic sensor element to move between the first electrode and the second electrode.The dilatometer of claim 5, wherein the internal magnetic sensor element is porous and configured to allow electrolyte of the battery cell to pass through the internal magnetic sensor element.The dilatometer of claim 5, wherein the internal magnetic sensing element is coated with a non-conductive material.The dilatometer of claim 1, further comprising a carrier between the first electrode and the second electrode, the carrier carrying the first electrode and configured to allow ions to pass through the carrier to move between the first electrode and the second electrode.The dilator of claim 8, wherein the internal magnetic sensor element is disposed adjacent the first electrode and is configured to move away from the magnetic force sensor when the first electrode expands during dilation and remain stationary when the second electrode expands during dilation.The dilatometer of claim 1, wherein the magnetic force sensor further comprises a load sensor, a strain gauge, a pressure sensor, or an electromagnetic force recovery sensor.

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