Internal short-circuit detection and attenuation in batteries

Abstract

Battery, including: an anode; a cathode; an electrically insulating separator with a sensing film located between the anode and the cathode, wherein the electrically insulating separator electrically isolates the anode from the cathode, and wherein the sensing film contains three or more sensing tabs located at a periphery of the sensing film; and a detection circuit arrangement that is electrically connected to each of the three or more detection flags and is configured to Determine at least one resistance, current, or voltage across each of the three or more detection flags, and Outputting a reading of at least one of the resistance, current, or voltage at each of the three or more sensing flags.

Description

INVENTION AREA

[0001] Embodiments of the invention generally relate to batteries and in particular to the detection and attenuation of internal short circuits caused by dendrite formation in a battery. GENERAL STATE OF THE ART

[0002] Rechargeable lithium batteries are attractive energy storage devices for portable electrical and electronic equipment and electric and hybrid-electric vehicles due to their high specific energy compared to other electrochemical energy storage devices. A typical lithium cell contains a negative electrode, a positive electrode, and a separator located between the negative and positive electrodes. Both electrodes contain active materials that react reversibly with lithium. In some cases, the negative electrode may contain lithium metal, which can be reversibly dissolved and deposited electrochemically. The separator contains an electrolyte with a lithium cation and acts as a physical barrier between the electrodes, ensuring that neither electrode is electrically connected within the cell.

[0003] Typically, during charging, electrons are generated at the positive electrode and consumed by an equal amount of electrons at the negative electrode. During discharging, the opposite reactions occur.

[0004] Lithium dendrites (needle- or tree-like growth) can form during repeated charge / discharge cycles of a battery. These dendrites can penetrate the battery's separator region and cause an internal short circuit between the negative and positive electrodes. The rapid discharge caused by this short circuit can release excessive heat within the battery, leading to battery damage. BRIEF OVERVIEW

[0005] Conventional approaches to treating dendrite formation have involved modifying the electrolyte and electrolyte solvent, as well as modifying the electrode surface morphologies. Despite these ongoing efforts, dendrite formation persists. The uneven (re)deposition of lithium during battery charge / discharge cycles often leads to dendrite formation. Therefore, there is a need for a system and method to detect and attenuate dendrites within a rechargeable battery before an internal short circuit occurs between the positive and negative electrodes.

[0006] A brief description of certain embodiments disclosed herein is set forth below. It is understood that these aspects are presented merely to provide the reader with a brief overview of these particular embodiments and that these aspects are not intended to limit the scope of protection afforded by this disclosure. Indeed, this disclosure may include a multitude of aspects that may not be set forth below.

[0007] One embodiment relates to a method for detecting and treating the formation of lithium dendrites in a battery, and in particular a method for identifying a dendrite material in the battery. In one example, the method for identifying a dendrite material in the battery includes receiving, by a battery management system, an output from a sensing circuit arrangement within a battery cell indicating a first voltage level, detecting a change from the first voltage level to a second voltage level indicating an internal short circuit between an electrode and a sensing foil, determining a resistance and a two-dimensional position of the internal short circuit on the sensing foil, and identifying a dendrite material based on the resistance of the internal short circuit.

[0008] Another embodiment provides a battery. In one example, the battery comprises an anode, a cathode, an electrically insulating separator, and a sensing circuit arrangement. The electrically insulating separator has a sensing foil and is located between the anode and the cathode. The electrically insulating separator electrically isolates the anode from the cathode and includes at least three sensing tabs located around the periphery of the sensing foil. The sensing circuit is electrically connected to each of the three or more sensing tabs and is configured to determine at least one resistance, current, or voltage across each of the three or more sensing tabs. The sensing circuit arrangement outputs a reading of the at least one resistance, current, or voltage across each of the three or more sensing tabs.

[0009] Yet another embodiment provides a system comprising a battery and a battery management system. In one example, the battery has an anode, a cathode, an electrically insulating separator, and a sensing circuitry. The electrically insulating separator has a sensing foil and is located between the anode and the cathode. The electrically insulating separator electrically isolates the anode from the cathode, and the sensing foil contains three or more sensing tabs located at the periphery of the sensing foil. The sensing circuitry is electrically connected to each of the three or more sensing tabs and configured to determine at least one resistance, current, or voltage across each of the three or more sensing tabs.The sensing circuit arrangement outputs a reading of at least one of the resistance, current, or voltage across each of the three or more sensing flags. The battery management system is communicatively connected to the battery and configured to receive the output from the sensing circuit arrangement and determine a resistance and a two-dimensional position of the internal resistance on the sensing foil based on the output from the sensing circuit arrangement.

[0010] The details of one or more features, aspects, implementations and benefits of this disclosure are set forth in the accompanying drawings, detailed description and claims below. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic representation of a battery cell and detection circuit arrangement according to one embodiment. Fig. Figure 2 is a schematic representation of a battery cell according to one embodiment. Fig. Figure 3A is a schematic representation of a battery cell according to another embodiment. Fig. Figure 3B is a schematic representation of a battery cell according to certain embodiments. Fig. Figure 4 is a schematic representation of a detection film within a battery cell according to one embodiment. Fig. 5A and Fig. Figure 5B is a schematic representation of a battery system comprising a battery cell and a battery management system according to some embodiments. Fig. Figure 6 is a schematic representation of a battery system comprising a battery detection film and a battery management system according to one embodiment. Fig. Figure 7 is a schematic representation of a detection film within a battery according to one embodiment. Fig. Figure 8 is a schematic representation of a detection foil within a battery according to an execution plan. Fig. Figure 9 is a flowchart illustrating an exemplary method for identifying the presence of an internal short circuit in a battery according to one embodiment. Fig. Figure 10 is a flowchart illustrating an exemplary procedure for identifying and dealing with the presence of an internal short circuit in a battery according to one embodiment. DETAILED DESCRIPTION

[0011] One or more specific embodiments are described below. Various modifications to the described embodiments are readily apparent to a person skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without deviating from the concept and scope of protection of the described embodiments. Thus, the described embodiments are not limited to the embodiments shown, but they are to be afforded the broadest scope of protection consistent with the principles and features disclosed herein.

[0012] One embodiment of a battery cell 100 is in Fig. Figure 1 shows the battery cell 100. In the illustrated example, the battery cell 100 includes an anode tab 110, an anode 120, a separator 130, detection tabs 140A, 140B, and 140N (collectively, "detection tabs 140"), a cathode 150, a cathode tab 160, and a detection circuit arrangement 170. In some examples, the separator 130 may be an electrically insulating separator. In some embodiments, the electrically insulating separator comprises a porous polymer film. For ease of understanding, the detection tabs 140 are shown positioned at the edge of the separator 130. It is understood that in some embodiments, the detection tabs 140 are connected to a single detection film (not shown) located within the separator 130.

[0013] In various embodiments, the sensing circuit arrangement 170 can be configured to measure parameters such as at least one of voltage, current, or resistance between a combination of the anode 120, a sensing foil within the separator 130, and the cathode 150. The sensing circuit arrangement 170 can also be configured to communicate with a device outside the battery cell 100. For example, the sensing circuit arrangement 170 can be configured to communicate with a battery management system. In some examples, the sensing circuit arrangement 170 can communicate with a battery management system outside the battery cell 100 by adjusting a voltage across the anode tab 110 and the cathode tab 160.

[0014] The battery cell 100 has a stacked architecture, which is indicated by reference to Fig. 2 is the best place to see it. Fig. Figure 2 illustrates a battery cell 200, which is similar to battery cell 100. In the example shown, the battery cell 200 contains a stack of components 205. The stack of components 205 includes an anode current collector 210, an anode current collector tab 220 attached to the anode current collector 210, and an anode 230. The battery cell 200 also includes a first separator 240 (e.g., a first electrically insulating separator) and a detection foil 250. The detection foil 250 has a detection tab 255. A second separator 260 (e.g., a second electrically insulating separator) is located opposite the first separator 240 at the detection foil 250, so that the detection foil 250 is positioned between the first separator 240 and the second separator 260. The battery cell 200 also contains a cathode 270, a cathode current collector 280 and a cathode current collector flag 290 attached to the cathode current collector 280.In the example shown, . Fig. In this respect, the first separator 240 is thinner than the second separator 260. In this way, the battery cell 200 is configured to detect a metallic dendrite growing from the anode 230 early in its formation, thereby minimizing its ability to cause damage within the battery cell 200.

[0015] Two embodiments of a battery cell are described in Fig. 3A and Fig. 3B shown. Fig. Figure 3A shows a battery cell 300 containing an anode current collector 320, which has an anode current collector tab 310. The anode current collector 320 is positioned at an anode 330. A first separator 340 is positioned at the anode 330, and a detection foil 350 with a detection tab 355 is positioned at the separator 340. A second separator 360 is positioned at the detection foil 350. Thus, the detection foil 350 is positioned between the first and second separators 340 and 360. The battery cell 300 also contains a cathode 370 and a cathode current collector 380, which has a cathode current collector tab 390. Fig. Figure 3B shows a battery cell 395. The battery cell 395 contains a stack of components 397. The battery cell 300 and the battery cell 395 are the same, except that instead of a first separator 340 and a second separator 360, the battery cell 395 contains a separator 361 between the detection foil 350 and the cathode 370, which corresponds to the second separator 360, as shown in Fig. 3A is described, similarly. In the example shown from Fig. 3A, the thickness of the first separator 340 and the thickness of the second separator 260 are essentially similar. In this way, the battery cell 300 is configured to detect a dendrite formed on the cathode 270 at a time similar to that formed on the anode 230, assuming that the dendrites appear at similar times and grow at similar rates.

[0016] In battery cells 300 and 395, the detection film 350 is located at at least one separator. However, the detection film 350 may be located at other positions within the battery cell 300 or 395, as may be the case. In certain embodiments, the anode 330 may contain an electrically insulating buffer layer, such as aluminum oxide (Al₂O₃), between the anode 330 and the separator 340. In one embodiment, the inclusion of the electrically insulating buffer layer may allow the detection film 350 to be placed at the anode 330 without a separator 340 between the separator 340 and the anode 330. It is understood that the electrically insulating buffer layer is a safety factor layer of the anode 330. The lack of a separator (e.g. the first separator 340) between the detection foil 350 and the anode 330 allows the detection foil 350 to be arranged in closer proximity to the anode 330.Earlier detection of dendrite formation is possible with such configurations because shorter dendrites can be detected when the detection foil 350 is located closer to an electrode (e.g., the anode 330). Similarly, if early detection of dendrite formation at the cathode 370 is desired, the detection foil 350 can be positioned similarly closer to the cathode 370 by placing the separator 361 between the anode 330 and the detection foil 350 instead of between the cathode 370 and the detection foil 350, as in the example shown. Fig. Figure 3B shows the components of the battery cells 300, 395. In various embodiments, the thickness of the components can be approximately 10 to 15 micrometers for the anode current collector 320, approximately 5 to approximately 100 micrometers for the anode 330, less than approximately 10 micrometers for the separator 340, or in certain embodiments approximately 2 to approximately 3 micrometers for the separator 340, approximately 50 to approximately 100 nanometers for the sensing film 350, approximately 10 to approximately 25 micrometers for the separator 360, approximately 50 to approximately 100 micrometers for the cathode 370, and approximately 10 to approximately 20 micrometers for the cathode current collector 380.

[0017] As noted above, dendrite formation occurs during charge / discharge cycles. The following text provides a description of a charge / discharge cycle for battery cell 395. However, the concepts discussed also apply to battery cells 100, 200, and 300.

[0018] During discharge of battery cell 395, lithium is oxidized at the anode 330, forming a lithium ion. The lithium ion migrates through the separator 361 of battery cell 395 to the cathode 370. During charging, the lithium ions return to the anode 330 and are reduced to lithium. In the case of a lithium anode 330, the lithium can be deposited as lithium metal on the anode 330. In the case of an insertion material anode 330, such as graphite, it can be inserted into the host structure, and the process is repeated with subsequent charge and discharge cycles. In the case of a graphitic or other Li insertion electrode, the lithium cations combine with electrons and the host material (e.g., graphite), leading to an increase in the degree of lithiation or "state of charge" of the host material. For example, x Li + + xe - + C6 →Li xC6. An excessively high charging current can lead to lithium metal deposition on the surface of the negative electrode, which in turn could result in uneven lithium deposition, leading to the development of a lithium dendrite on the surface of the anode 330. Without attenuation, as the dendrite length increases, it can span the separator 361 and form an internal short circuit between the anode 330 and the cathode 370. The placement of a detection foil 350 between the anode 330 and the cathode 370 allows for the detection and identification of dendrite formation before the dendrite creates an internal short circuit between the anode 330 and the cathode 370.In other words, placing the detection foil 350 between the anode 330 and the cathode 370 allows for a different internal short circuit, either between the anode 330 or the cathode 370 and the detection foil 350, so that dendrite formation can be detected and identified. Furthermore, in some examples, dendrite formation can also be attenuated to prevent a typical internal short circuit between the anode 330 and the cathode 370.

[0019] The anode 330 can comprise an oxidizable metal such as lithium or an insertion material capable of inserting Li or another ion such as Na, Mg, etc. The cathode 370 can consist of various materials such as sulfur or sulfur-containing materials (e.g., polyacrylonitrile-sulfur composites (PAN-S composites), lithium sulfide (Li₂S)); vanadium oxides such as vanadium pentoxide (V₂O₅); metal fluorides such as fluorides of titanium, vanadium, iron, cobalt, bismuth, copper, and combinations thereof; lithium insertion materials such as lithium nickel manganese cobalt oxide (NMC), lithium-rich NMC, lithium nickel manganese oxide (LiNi). 0.5 Mn 1.5O4), lithium-rich coated oxides such as lithium cobalt oxide (LiCoO2), lithium iron phosphate (LiFePO4), lithium manganese oxide (LiMn2O4), lithium nickel cobalt aluminum oxide (NCA), and combinations thereof. The particles may further be suspended on a porous, electrically conductive matrix containing a polymeric binder and electrically conductive material such as carbon (carbon black, graphite, carbon fiber, etc.). In some examples, the cathode may have an electrically conductive material with a porosity exceeding 80% to allow the formation and deposition / storage of oxidation products such as lithium peroxide (Li2O2) or lithium sulfide (Li2S) within the cathode volume. The ability to directly deposit the oxidation product determines the maximum power output obtainable from the battery cell. Materials that provide the required porosity include carbon black, graphite, carbon fibers, carbon nanotubes and other non-carbon materials.The pores of the cathode 370, the separators 340, 360, 361, the detection foil 350, and the anode 330 are filled with an ion-conducting electrolyte containing a salt such as lithium hexafluorophosphate (LiPF6), which provides the electrolyte with adequate conductivity to reduce the internal electrical resistance of the battery cell. The electrolyte solution enhances ion transport within the battery cell. Various types of electrolyte solutions are available, including non-aqueous liquid electrolytes, ionic liquids, solid polymers, glass-ceramic electrolytes, and other suitable electrolyte solutions.

[0020] The anode current collector 320 and the cathode current collector 380 are electrically conductive materials that conduct electrons between the electrode and electrode tabs of the cell. The materials of current collectors can also be efficient thermal conductors, allowing heat generated within the battery cell 300, 395 to be dissipated from the battery cell 300, 395. In some examples, the current collectors can contain various metals or carbon-based materials. For example, the current collectors can contain graphite, aluminum, copper, gold, platinum, magnesium, or titanium.In various embodiments, the current collector materials can be selected such that the current collector tabs 310 and 390 are resistant to potentially harmful effects caused by exposure to the atmosphere, allowing the current collector tabs 310 and 390 to act as electrical contacts outside the battery cell 395. In certain embodiments, the anode current collector 320 can be made of copper and the cathode current collector 380 of aluminum.

[0021] The Separator 361 from Fig. 3B or the first and second separators 340 and 360, as in Fig. As described in 3A, the separator can comprise one or more electrically insulating, ion-conducting materials. In some examples, suitable materials for separator 361 may include porous polymers, ceramics, and two-dimensional film structures such as graphene, boron nitride, and dichalcogenides.

[0022] One embodiment of a detection film 400 is in Fig. 4 shown. In the example of Fig. 4 contains the recording sheet 400, recording flags 410, 420 and 430 along the periphery of the recording sheet 400. Fig. 4 also includes an anode current collector vane 440 connected to an anode below the detection foil 400. In the example shown of Fig. 4 The recording sheet 400 has three recording flags 410, 420 and 430 along the periphery of the recording sheet 400, but a different number of additional recording flags can be used along the periphery of the recording sheet 400, provided that the recording flags remain spatially separated from each other.

[0023] In one embodiment, the detection film 400 and the detection flags 410, 420, 430 can be formed from a thin layer of an electrically conductive material. In some examples, the electrically conductive material can be a metal selected from the group consisting of copper, aluminum, titanium, platinum, gold, and combinations thereof. In one example, the detection film 400 can be a single layer. In another example, the detection film 400 can be a multilayer film with a combination of different conductive / conductive or conductive / non-conductive materials. In yet another example, the detection film 400 can be a flexible film, a foldable film, or a combination thereof.

[0024] One embodiment of a 500A battery system is in Fig. 5A shown. The battery system includes an anode tab 510, an anode 520, a separator 530, detection tabs 540A, 540B and 540N (collectively “detection tabs 540”), a cathode 550, a cathode tab 560, a detection circuit arrangement 570 and a battery management system 580. In some embodiments, the detection tabs 540 can be the one that is part of the detection foil 400 in Fig. The 4 depicted recording flags correspond to 410, 420, 430.

[0025] In the example of Fig. 5A corresponds to the battery cell 502, the anode tab 510, the anode 520, the separator 530, the detection tabs 540, the cathode 550, the cathode tab 560 and the detection circuit arrangement 570 of the battery cell 100, the anode tab 110, the anode 120, the separator 130, the detection tabs 140, the cathode 150, the cathode tab 160 and the detection circuit arrangement 170 respectively, as in Fig. 1 described. In contrast to Fig. 1 contains the system 500A in the example of Fig. 5A continues to include a battery management system 580. The battery management system 580 is communicatively connected to the battery cell 502. In one example, the battery management system 580 is electrically connected to the battery cell 502 via electrical connections (e.g., wires). In another example, the battery management system 580 can be wirelessly connected to the battery cell 502 via a radio communication network. The battery management system 580 can, for example, be a microcontroller (with memory and input / output components on a single chip or within a single package) or can contain separately configured components, such as a microprocessor, memory, and input / output components.The Battery Management System 580 can also be implemented using other components or combinations of components, including, for example, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or another circuit arrangement. Depending on the desired configuration, the processor can include one or more levels of caching, such as a level cache memory, one or more processor cores, and registers. The example processor core can include an arithmetic logic unit (ALU), a floating-point unit (FPU), or any combination thereof. The Battery Management System 580 can also include a user interface, a communication interface, and other computer-implemented facilities for performing features not defined here may be incorporated into the system.In one particular example, the battery management system may include 580 other computer-implemented facilities such as a communication interface, a user interface, a network communication link, and an interface bus to facilitate communication between different interface facilities, computer-implemented facilities, and one or more peripheral interfaces to the microprocessor.

[0026] The memory of the battery management system 580 can contain computer-readable instructions which, when executed by the electronic processor of the battery management system 580, cause the battery management system, and in particular the electronic processor, to perform or control the execution of various functions or procedures attributed to the battery management system 580 herein (e.g., detection of an internal short circuit resulting from dendrite formation, identification of dendrite material, and / or mitigation of the internal short circuit). The memory can contain any temporary, non-temporary, volatile, non-volatile, magnetic, optical, or electrical media, such as random-access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other digital or analog media.The functions assigned herein to the battery management system 580 can be embodied as software, firmware, hardware, or any combination thereof. For example, the battery management system 580 can be embedded in a computing device, and the sensing circuitry 570 is configured to communicate with the computing device's battery management system 580 located outside the battery cell 502. In this case, the sensing circuitry 570 is configured to have wireless and / or wired communication with the battery management system 580. For example, the sensing circuitry 570 and the battery management system 580 of the external device are configured to communicate with each other over a network.In yet another example, the battery management system 580 is located remotely at a server, and the data acquisition circuitry 570 is configured to transmit data from battery cell 502 to the battery management system 580. In the examples above, the battery management system 580 is configured to receive the data and send the data to an electronic device for display in a human-readable format. The computing device can be a mobile phone, tablet, personal digital assistant (PDA), laptop, computer, wearable, or other suitable computing device. The network can be a cloud computing network, server, wide area network (WAN), local area network (LAN), in-vehicle network, or other suitable network.

[0027] The battery management system 580 is configured to receive data from the sensing circuitry 570, including current, voltage, and / or resistance measurements. The battery management system 580 is also configured to determine the state of battery cell 502. Based on the determined state of battery cell 502, the battery management system 580 can modify the operating parameters of battery cell 502 to maintain its internal structure. The battery management system 580 can also inform a user about the state of battery cell 502.

[0028] Another embodiment is shown in the example of Fig. 5B is shown as a System 500B. The System 500B of Fig. 5B is similar to the 500A system from Fig. 5A, except that the detection circuit arrangement 570 is located outside the battery cell 502. As in Fig. As shown in Figure 5B, the sensing circuit assembly 570 is separate from the battery cell 502 and the battery management system 580. It is understood that the specific type, number, and configuration of the components, including the sensing circuit assembly 570, are shown as examples in systems 500A and 500B in Figure 5B. Fig. 5A or 5B are provided. In other embodiments, systems 500A and 500B can be used in Fig. 5A and Fig. 5B fewer or additional components in various combinations and configurations than in Fig. 5A and Fig. 5B shown. For example, in other embodiments, the detection circuit arrangement 570 is part of the battery management system 580, and the battery management system 580 is directly connected to the detection flags 540 inside the battery cell 502.

[0029] One embodiment of a system 600 is in Fig. 6 shown. In the example of Fig. In Figure 6, the system 600 includes a battery cell 602, a detection foil 620, detection foil flags 630, 640 and 650, an anode current collector flag 660, a detection circuit assembly 670 and a battery management system 680. In the example of Fig. 6. Battery cell 602, sensing circuit arrangement 670, and battery management system 680 correspond to battery cell 502, sensing circuit arrangement 570, and battery management system 580, as described in Figure 6. Fig. 5 described.

[0030] The battery management system 680 uses the sensing circuit arrangement 670 to collect voltage and / or current data between the anode current collector tab 660 and the sensing foil 620. For example, the sensing circuit arrangement 670 can individually measure the voltage and / or current between each of the sensing tabs 630, 640, and 650 and the anode current collector tab 660. The measured parameters are then used by the battery management system 680 to determine states within the battery cell 602.

[0031] To detect dendrite formation, the battery management system 680 can detect a current circuit formed between the detection tabs 630, 640, and 650 and the anode current collector tab 660. The voltage V measured between each detection tab 630, 640, and 650 and the anode current collector tab 660 m and the current I applied to the anode current collector vane 660 sThe battery management system 680 can use this information to determine additional details about the internal short circuit. For example, the battery management system 680 can determine the position (e.g., a two-dimensional position) and resistance of the dendrite. In determining the position and resistance, the battery management system 680 can also identify the dendrite material based on the determined resistance. Identifying the dendrite material can allow the battery management system 680 to perform additional actions (e.g., actions to mitigate the potential effects of the dendrite within the battery cell 602).

[0032] By determining the presence of a dendrite between the unseen anode and the detection foil 620, before the dendrite penetrates the separator region and potentially creates an internal short circuit between the battery's anode and cathode, corrective actions can be taken. The battery management system 680 can take various actions depending on the composition, number, and location of the detected dendrites. For example, if a dendrite is lithium, the battery management system 680 can cause or provide a current flow through the dendrite sufficient to raise its temperature above the melting point of lithium, approximately 180 degrees Celsius, thereby melting the dendrite and eliminating the short circuit it has caused.If the dendrite is made of a higher-melting-point material such as copper, iron, nickel, chromium, cobalt, or manganese, the 680 battery management system can instruct a user that the battery requires maintenance. For example, the 680 battery management system can instruct a technician to replace a specific battery cell (e.g., battery cell 602). In this example, the 680 battery management system can also instruct a technician that a dendrite is forming and that the dendrite cannot be weakened by heat treatment. In some examples, the 680 battery management system, the user, or the technician can initiate a shutdown protocol for the battery, allowing the battery to be serviced.

[0033] Fig. Figure 6 illustrates a capture sheet 620 with three capture flags 630, 640 and 650 along the periphery of the capture sheet 620, but additional capture flags may be included, provided that the capture flags remain electrically separated from each other.

[0034] Although the sensing circuit arrangement 670 has been described here as measuring electrical parameters between each of the sensing tabs 630, 640, and 650 and the anode current collector tab 660, the sensing circuit arrangement 670 can also be used to measure electrical parameters between each of the sensing tabs 630, 640, and 650 and a cathode current collector tab. A similar system to the one described in Fig. The system 600 shown in Figure 6 can be used to detect and identify internal short circuits that form on the cathode. For example, the electrolyte may contain additives that polymerize when the cathode reaches a high potential. The resulting polymer is slightly electrically conductive and can create a high-resistance internal short circuit through the separator, which can cause the battery management system 680 to safely shut down the cell. A battery structure with a detection film as part of the separator area could potentially detect the formation of such internal short circuits and instruct the user to replace the affected battery cell.

[0035] The resistance between the anode current collector tab 660 and each of the sensing tabs 630, 640, and 650 contains several components in series. The first resistance component is the negative tab / negative current collector contact resistance. The second resistance component is the resistance in the negative electrode from the negative tab to the internal short circuit. The third resistance component is the internal short-circuit resistance. The fourth resistance component is the resistance in the sensing foil from the internal short circuit to the sensing tab. The fifth resistance component is the sensing foil / sensing tab contact resistance.

[0036] Welding on the detection flags 630, 640, and 650 is expected to minimize the flag contact resistances or, if significant, allow the contact resistances to be measured in advance, with the resistance in the anode being much lower than that in the detection foil 620. For example, a typical copper current collector thickness of 10 micrometers or more is compared with a detection foil thickness of approximately 50 nm to 100 nm, resulting in a resistance in the detection foil 620 that is, on average, two orders of magnitude higher than that in the anode. The resistances of typical dendrites (e.g., copper or lithium dendrites with a diameter of approximately 1 micrometer through a 25-micrometer separator) are of approximately the same order of magnitude as the resistance through the detection foil 620 (e.g., a 50 nm thick foil measuring 5 cm wide and 5 cm long).

[0037] The 680 battery management system can perform the following actions, as described in Fig. 7 shown and described below to determine the resistance of the internal short circuit 722 and its position on the sensing foil 720, which corresponds to the sensing foil 620 as in Fig. The battery management system 680 can determine the origin of the two-dimensional space at a corner of the sensing foil 720. Relative to the origin, the internal short circuit 722 is located at the unknown position (x0, y0), and the location of one of the sensing flags 730 is at the known coordinate (x1, y1). The length and width of the sensing foil 720 are L and W, respectively. The battery management system 680 can define a circle with radius r0, centered at (x0, y0), around the internal short circuit 722 and a semicircle with radius r1, centered at (x1, y1), around the sensing flag 730. When measuring the voltage V m A very small current is applied to the detection circuit. ssuch that the total DC resistance of the detection circuit can be determined by dividing the measured voltage V m , through the applied current i s , as defined by Equation 1. RDC=RS+Rss=Vm / is

[0038] In equation 1, R S the resistance of the internal short circuit 722, and R ss is the resistance of the detection foil 720.

[0039] Within the limits r0→ 0 and r1→ 0, the current density in all directions normal to the circle, as defined by equation 2, and semicircle, as defined by equation 3, can be approximated as uniform. iϖ=iS2πr0dn^_ iϖ=iSπr1dn^

[0040] In equations 2 and 3, d is the thickness of the detection film and n̂ is the unit normal to the circle or semicircle in the xy-plane. Components i x and i yWritten out, equations 2 and 3 can be redefined as equations 4 and 5 for the circle and semicircle respectively. ix=iS2πr02d(x−x0),iy=iS2πr02d(y−y0)_ ix=iSπri2d(x−x1),iy=iS2πr12d(y−y1)

[0041] In general, r0 < r1 << W < L, the battery management system 680 can use the above approximation when calculating the voltage drop between the internal short circuit 722 and the detection flag 730.

[0042] Within the area of ​​the capture sheet 720, which lies outside the circle and semicircle, there are no additional current sources or sinks, and therefore the Laplace equation applies, as defined by equation 6. ∇2ϕ=0_

[0043] In equation 6, ϕ is the potential in the acquisition foil 720. This is derived from the current balance, as defined by equation 7, and Ohm's law, as defined by equation 8. ∇⋅iω=O_ ιω=−σ v φ

[0044] Both equations 7 and 8 apply in the area of ​​the detection foil 720 outside the circle and semicircle. The battery management system 680 can establish an arbitrary reference voltage. For example, the battery management system 680 can prescribe the reference voltage at the origin as defined by equation 9. ϕ(0,0)=0

[0045] The voltage drop and the effective resistance through the sensing foil 720 are defined by equations 10 and 11. Vss=ϕ(x1,y1)−ϕ(x0,y0) RSS=Vss / is

[0046] Since the value of ϕ is not explicitly calculated at these positions, the battery management system 680 can approximate the potentials by averaging the potential values ​​at the respective peripheries of the circle and semicircle.

[0047] A variety of methods can be used by the Battery Management System 680 to solve the above set of equations to determine the effective detection foil resistance or voltage drop, provided the position and resistance of the internal short circuit 722 are known. In one exemplary method, the Battery Management System 680 can map the rectangular domain to the semi-infinite domain via a Schwarz-Christoffel transform, using the solution to the Laplace equation derived in the semi-infinite domain, and the Battery Management System 680 can map the solution back to the rectangular domain. In another exemplary method, the Battery Management System can solve the Laplace equation in the rectangular domain via a separation of variables, resulting in a series expansion solution in x and y for the potential.In yet another exemplary procedure, the 680 battery management system can numerically calculate the Laplace equation using a finite difference, a finite volume, a control volume, or other numerical methods. In another exemplary procedure, as in . Fig. As shown in Figure 8, the battery management system 680 can approximate the detection foil 720 as a discrete network of resistors in two dimensions and solve the equations resulting from Kirchhoff's current and voltage laws.

[0048] Furthermore, the position (x0, y0) and the resistance (R) can be set. SThe internal short circuit 722 can be determined from at least three independent measurements of the total DC resistance. The battery management system 680 can measure the voltage drop between the anode tab and three or more separate sensing tabs along the periphery of the sensing foil 720. If, in some examples, three different tabs exist at different locations on the periphery, then the battery management system 680 can analogously provide three different measurements of the sensing circuit's total resistance by alternately closing the circuit to each of the three tabs. In other examples, more than three different measurements can be used to obtain a unique solution to the set of variables (R). S to determine , x0, y0).

[0049] The battery management system 680 can measure the voltage of the sensing circuit subject to an applied current of known magnitude, which is a technique for obtaining the values ​​of the resistance and the position of the internal short circuit 722. Additionally, or alternatively, in some examples, the resistance of each sensing circuit can be measured by applying a specified voltage and measuring the current.

[0050] A flowchart of the function of an embodiment of the battery management system 580 by Fig. 5 for the detection of an internal short circuit is in Fig. 9 presented. Fig. 9 is referred to as system 500A by Fig. 5A is described. The battery management system 580 receives an output from the sensing circuit arrangement 570 indicating a first voltage level (block 902). The battery management system 580 detects a change from the first voltage level to a second voltage level, indicating an internal short circuit within the sensing foil (block 904). The battery management system 580 determines the resistance and location of the internal short circuit within the sensing foil (block 906). The battery management system 580 identifies the material of the dendrite based on the determined resistance of the dendrite (block 908). In some examples, the battery management system 580 can handle the internal short circuit based on the identified dendrite material (block 910).

[0051] A flowchart of the function of an embodiment of the battery management system 680 for the detection of an internal short circuit is presented in Fig. 10 presented. Fig. 10 is referred to by System 600. Fig. 6 described. The battery management system 680 sets a current i s and monitors a first voltage level (V m1 ) between the anode current collector flag 660 and a first detection flag 630 (block 1000). If the battery management system 680 does not detect a change in the first voltage level (NO at decision block 1002), the battery management system 680 continues to monitor the first voltage level (block 1000). However, if the battery management system 680 detects that the first voltage level is below a threshold voltage level (YES at decision block 1002), then the battery management system 680 opens the circuit to the first detection flag 630 (block 1004). The battery management system 680 closes the circuit to a second detection flag 640, sets the current i s and measures a second voltage level (V m2) (Block 1006). After measuring the second voltage level, the battery management system 680 opens the circuit to the second detection flag 640 (Block 1008). The battery management system 680 closes the circuit to a third detection flag 650, applies the current i s and measures a third voltage level (V m3 ) (Block 1010). Based on the measured voltage levels and applied currents, the 680 battery management system determines the resistance Rs and the two-dimensional position corresponding to the internal short circuit (Block 1012). In some examples, the 680 battery management system can determine a treatment based on the determined resistance Rs of the internal short circuit.

[0052] The battery management system 680 determines whether the resistance (Rs) is below a threshold resistance. If the battery management system 680 detects that the resistance (Rs) is above a threshold resistance (NO at decision block 1014), the battery management system 680 either activates a dendrite elimination protocol to eliminate the dendrite or monitors the initial voltage level of the first detection flag 630 (block 1018). In some examples, the dendrite elimination protocol may involve a current through the internal short circuit sufficient to heat the dendrite above its melting point. For example, the battery management system 680 may identify the dendrite as a lithium dendrite, and the battery management system 680 may send a current through the lithium dendrite that raises the temperature above 180 degrees Celsius to melt the lithium dendrite.The applied current will also raise the temperature of the parts of the sensing circuit through which the current flows. In some embodiments, the circuit of the applied current can be alternated between different sensing tabs 630, 640, 650 to limit the extent of heating of any given part of the sensing foil 620, while localizing the area of ​​continuous heating to the internal short circuit itself. In some embodiments, additional sensing tabs can be added to further differentiate between the sensing foil 620 and the internal short circuit when the cell temperature is raised. The battery management system 680 can activate the dendrite elimination protocol or continue to monitor the initial voltage level if there is no change in the initial voltage level (NO at decision block 1020).However, the battery management system 680 can disable the dendrite elimination protocol and restart the dendrite identification process if there is a change in the initial voltage level (YES at decision block 1020).

[0053] If the battery management system 680 detects that the resistance (Rs) is below a threshold resistance (YES at decision block 1014), the battery management system 680 activates a battery shutdown protocol. In some examples, the resistance (Rs) of copper is below the predetermined threshold that will cause the battery management system 680 to activate the battery shutdown protocol.

[0054] The embodiments described above have been shown as examples, and it is understood that these embodiments are suitable for various modifications and alternative forms. It is further understood that the claims are not limited to the specific forms disclosed, but rather cover all modifications, equivalents, and alternatives that fall within the scope and protection of this disclosure.

[0055] It is assumed that the embodiments described herein and many of their associated advantages are understood from the above description, and it will be obvious that various modifications regarding the shape, construction, and arrangement of the components can be made without departing from the disclosed subject matter and without sacrificing all its material advantages. The described form is merely illustrative, and the following claims are intended to include and encompass such modifications.

Claims

[1] Battery, comprising: an anode; a cathode; an electrically insulating separator with a sensing film located between the anode and the cathode, wherein the electrically insulating separator electrically isolates the anode from the cathode, and wherein the sensing film contains three or more sensing tabs located at a periphery of the sensing film; and a detection circuit arrangement that is electrically connected to each of the three or more detection flags and is configured to Determine at least one resistance, current, or voltage across each of the three or more detection flags, and Outputting a reading of at least one of the resistance, current, or voltage at each of the three or more sensing flags. [2] Battery according to claim 1, further comprising an anode current collector at the anode and an anode current collector vane attached to the anode current collector. [3] Battery according to claim 1, further comprising a cathode current collector at the cathode and a cathode current collector vane attached to the cathode current collector. [4] Battery according to claim 1, wherein the electrically insulating separator with the detection film comprises a first electrically insulating separator and a second electrically insulating separator and wherein the detection film is located between the first electrically insulating separator and the second electrically insulating separator. [5] Battery according to claim 1, wherein the electrically insulating separator further comprises a porous polymer film between the detection film and at least one of the cathode or the anode. [6] Battery according to claim 1, wherein the detection foil contains a material selected from the group consisting of copper, aluminium, titanium, platinum and gold. [7] Method for identifying a dendrite material within a battery, the method comprising: Received, by a battery management system, an output from the sensing circuitry within the battery, indicating an initial voltage level; Detect, by the battery management system, a change from the first voltage level to a second voltage level, which indicates an internal short circuit between an electrode and a sensing foil; Determined by the battery management system, a resistance and a two-dimensional position of the internal short circuit on the detection foil; and Identify, through the battery management system, a dendrite material based on the resistance of the internal short circuit. [8] Method according to claim 7, further comprising the treatment, by the battery management system, of the internal short circuit based on an identification of the dendrite material. [9] Method according to claim 8, wherein the treatment of the internal short circuit comprises activating, by the battery management system, a dendrite elimination protocol, wherein the dendrite elimination protocol includes sending a current through the internal short circuit and wherein the current is sufficient to raise the temperature of the dendrite material above a melting point of the dendrite material. [10] Method according to claim 8, wherein the treatment of the internal short circuit comprises activating, by the battery management system, a battery shutdown protocol. [11] Method according to claim 7, wherein receiving, by the battery management system, the output from the sensing circuit arrangement within the battery, indicating the first voltage level, includes applying a current and monitoring a first voltage level between an anode and a first sensing flag. [12] Method according to claim 7, wherein the detection by the battery management system of the change from the first voltage level to the second voltage level, which indicates the internal short circuit between the electrode and the sensing foil, comprises the detection by the battery management system when the first voltage level is below a threshold voltage level. [13] Method according to claim 7, wherein determining by the battery management system includes the resistance and the two-dimensional position of the internal short circuit on the detection foil: Applying a current and measuring a voltage level between an anode and a first detection flag; Applying a current and measuring a voltage level between the anode and a second detection flag; Applying a current and measuring a voltage level between the anode and a third detection flag; and Based on at least the applied currents and the measured voltage levels of the at least three detection flags, determining the resistance and the two-dimensional position according to the internal short circuit. [14] Method according to claim 7, wherein the identification, by the battery management system, of the dendrite material based on the resistance of the internal short circuit comprises determining, by the battery management system, whether the resistance of the dendrite material is below a threshold resistance. [15] System, encompassing: a battery that has the following features: an anode; a cathode; an electrically insulating separator with a sensing film located between the anode and the cathode, wherein the electrically insulating separator electrically isolates the anode from the cathode, and wherein the sensing film contains three or more sensing tabs located at a periphery of the sensing film; and a detection circuit arrangement that is electrically connected to each of the three or more detection flags and is configured to Determine at least one resistance, current, or voltage across each of the three or more detection flags, and Outputting a reading of at least one of the resistance, current, or voltage at each of the three or more sensing flags; and a battery management system that is communicatively connected to the battery and configured to Receiving the output from the acquisition circuit arrangement, and Determining a resistance and a two-dimensional position of the internal short circuit on the acquisition foil based on the output from the acquisition circuit arrangement. [16] System according to claim 15, wherein the battery management system is further configured to identify a dendrite material based on the resistance of the internal short circuit. [17] System according to claim 16, wherein the battery management system is further configured to treat the internal short circuit based on identification of the dendrite material. [18] System according to claim 17, wherein the battery management system is configured to handle the internal short circuit, comprising the battery management system configured to activate a battery shutdown protocol. [19] System according to claim 17, wherein the battery management system is configured to handle the internal short circuit, comprising the battery management system configured to activate a dendrite elimination protocol. [20] System according to claim 19, wherein the dendrite elimination protocol includes the battery management system configured to send a current through the internal short circuit, and wherein the current is sufficient to raise the temperature of the dendrite material above a melting point of the dendrite material.

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