Sensing device and method of operating the same

Abstract

A sensing device (100, 300) is disclosed, the sensing device sensing the structure of an electrode (108, 200A, 200B, 302) of a power cell (106). The electrode is arranged to have a layer (110, 112, 202, 206, 304, 306) spatially adjacent thereto, the layer (110, 112, 202, 206, 304, 306) providing a waveguide region (114, 308), the waveguide region comprising a surface of the electrode 5 with a structural change. The sensing device comprises a source (102, 310) of terahertz electromagnetic radiation and a coupling device (104, 312), the coupling device (104, 312) coupling the terahertz electromagnetic radiation from the source into the waveguide region. The terahertz electromagnetic radiation interacts with features present on the surface. The sensing device includes a detector (116, 314) that receives terahertz electromagnetic radiation reflected and / or transmitted through the waveguide region and processes the terahertz electromagnetic radiation to determine temporal variations therein that are indicative of dendritic growth or any manufacturing or structural defects occurring at the surface of the electrode.

Description

Technical Field

[0001] The present disclosure relates generally to battery management systems; and more particularly, to a sensing device for sensing a battery structure. In addition, the present disclosure relates to a method for sensing a battery structure. Background Art

[0002] Over the years, due to the intermittent supply and demand of electrical energy, power batteries have been increasingly used to make the supply of electricity more stable and predictable. In addition, batteries can store and retrieve electrical energy in a clean, safe, reliable and affordable way for the rapid development of smart grids and electric vehicles (EVs) and for remote areas that lack grid connection infrastructure. Typically, power batteries are composed of two or more electrochemical cells that convert stored chemical energy into electrical energy.

[0003] However, batteries require a battery management system (BMS) to operate safely, reliably and efficiently. Specifically, the battery management system prevents the battery from operating in an unsafe operating environment. In addition, the battery management system monitors the state of the battery by analyzing data related to the operating conditions (e.g., operating voltage, operating current, operating temperature, coolant flow, etc.) and estimating the state of charge (SoC), state of health (SoH), state of life (SoL), total useful capacity, deliverable power or power state (SoP), etc. In addition, the battery management system controls the operating conditions of the power battery by combining battery safety and protection, charging control, battery balancing and thermal management functions to prevent battery degradation in the event of hazardous conditions.

[0004] However, such battery management systems cannot monitor the degree of degradation of power batteries. Typically, battery management systems monitor the health of power batteries based on external characteristics of power batteries (e.g., heat dissipation, external damage, etc.), where the external characteristics are affected by the working conditions of the power batteries (e.g., temperature, pressure and humidity of the operating environment, power supply voltage, power supply current, and the nature of the load connected to the power battery). However, the aforementioned battery management system does not monitor any changes in the internal state of the power battery due to manufacturing or structural defects, physical and chemical changes that occur naturally over time, or operating parameters that change due to charging strategies (e.g., deep charging, overcharging, fast charging, etc.). Subsequently, the battery management system is unable to identify internal anomalies associated with the battery. Therefore, such lack of information about internal anomalies of power batteries can lead to dangerous results, such as short circuits, leaks, exothermic reactions, thermal runaway, multi-battery failures, exhaust, ruptures, and explosions. In addition, the occurrence of such dangerous events will affect the performance and efficiency of power batteries, bring challenges to emergency response teams, and further cause people to be in a state of confusion and turmoil due to the safety risks associated with them.

[0005] Therefore, in view of the foregoing discussion, there is a need to overcome the above-mentioned shortcomings associated with conventional battery management systems for monitoring the health of a battery throughout the operating life of the battery. Summary of the invention

[0006] The present disclosure seeks to provide a sensing device that senses the electrode structure of a power battery. The present disclosure also seeks to provide a method for sensing the electrode structure of a power battery. The present disclosure seeks to provide a solution to the existing problems associated with conventional battery management systems, which only analyze the operating conditions of the power battery to monitor its health. The purpose of the present disclosure is to provide a solution that at least partially overcomes the problems encountered in the prior art and provides a sensing device that senses the electrode structure of a power battery to monitor its health.

[0007] In one aspect, an embodiment of the present disclosure provides a sensing device, which senses the structure of an electrode of a power battery when in operation, wherein the electrode is arranged to have one or more layers that are spatially adjacent to form a waveguide region including a surface of the electrode, and the structure of the electrode changes as the state of charge of the power battery changes, wherein the sensing device comprises:

[0008] (i) a terahertz electromagnetic radiation source and coupling means for coupling terahertz electromagnetic radiation from the source into a waveguide region where the terahertz electromagnetic radiation interacts with one or more features present on a surface of the electrode; and

[0009] (ii) a detector that receives terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region and processes the reflected and / or transmitted terahertz electromagnetic radiation to determine temporal variations therein that are indicative of one or more dendritic growths occurring at the surface of the electrode.

[0010] In another aspect, an embodiment of the present disclosure provides a method for sensing an electrode structure of a power battery, wherein the electrode is arranged to have one or more layers that are spatially adjacent to form a waveguide region including a surface of the electrode, and the structure of the electrode changes as the state of charge of the power battery changes, wherein the method comprises:

[0011] (i) using a sensing device comprising a source of terahertz electromagnetic radiation and coupling means for coupling the terahertz electromagnetic radiation from the source into a waveguide region where it interacts with one or more features present at a surface of an electrode; and

[0012] (ii) receiving, using a detector, terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region, and processing the reflected and / or transmitted terahertz electromagnetic radiation to determine temporal variations therein, the temporal variations being indicative of one or more dendritic growths occurring at the surface of the electrode.

[0013] The embodiments of the present disclosure substantially eliminate or at least partially solve the above-mentioned problems in the prior art and are capable of accurately identifying anomalies in electrode structures, thereby allowing in-situ, in-operation, ex-situ or off-line prediction of batteries.

[0014] Other aspects, advantages, features and objects of the present disclosure will become apparent from the accompanying drawings and detailed description of illustrative embodiments interpreted in conjunction with the appended claims.

[0015] It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] When read in conjunction with the accompanying drawings, the above summary of the invention and the specific implementation of the illustrative embodiments below can be better understood. For the purpose of illustrating the present disclosure, an exemplary configuration of the present disclosure is depicted in the accompanying drawings. However, the present disclosure is not limited to the specific methods and means disclosed herein. In addition, those skilled in the art will understand that the accompanying drawings are not drawn to scale. Where possible, the same elements have been indicated with the same numbers.

[0017] Embodiments of the present disclosure will now be described, by way of example only, with reference to the following drawings, in which:

[0018] Figure 1 is a schematic diagram of a sensing device according to an embodiment of the present disclosure;

[0019] Figure 2A and Figure 2B is a schematic diagram of electrodes in a power battery according to various embodiments of the present disclosure;

[0020] Figure 3 is a schematic diagram of a sensing device according to an exemplary implementation of the present disclosure;

[0021] Figure 4 is a schematic diagram of a sensing device having a pouch cell and a transparent terahertz (THz) window according to an embodiment of the present disclosure; and

[0022] Figure 5 The steps of a method for sensing an electrode structure of a power battery according to an embodiment of the present disclosure are shown.

[0023] In the accompanying drawings, underlined numbers are used to indicate the item on which the underlined number is located or the item to which the underlined number is adjacent. Non-underlined numbers relate to the item identified by the line linking the non-underlined number to the item. When a number is non-underlined and is accompanied by an associated arrow, the non-underlined number is used to identify the general item to which the arrow points. DETAILED DESCRIPTION

[0024] The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of implementing the present disclosure have been disclosed, those skilled in the art will recognize that other embodiments for implementing or practicing the present disclosure are also possible.

[0025] In one aspect, embodiments of the present disclosure provide a sensing device that, when in operation, senses a structure of an electrode of a power battery, wherein the electrode is arranged to have one or more layers spatially adjacent thereto, the one or more layers providing a waveguide region including a surface of the electrode, the structure of the electrode changing, for example, as the state of charge of the power battery changes, wherein the sensing device comprises:

[0026] (i) a terahertz electromagnetic radiation source and coupling means for coupling terahertz electromagnetic radiation from the source into a waveguide region where the terahertz electromagnetic radiation interacts with one or more features present on a surface of the electrode; and

[0027] (ii) a detector that receives terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region and processes the reflected and / or transmitted terahertz electromagnetic radiation to determine temporal variations therein that are indicative of one or more dendritic growths occurring at the surface of the electrode.

[0028] In another aspect, an embodiment of the present disclosure provides a method for sensing an electrode structure of a power battery, wherein the electrode is arranged to have one or more layers spatially adjacent thereto, the one or more layers providing a waveguide region including a surface of the electrode, the structure of the electrode changing as the state of charge of the power battery changes, wherein the method comprises:

[0029] (i) using a sensing device comprising a source of terahertz electromagnetic radiation and coupling means for coupling terahertz electromagnetic radiation from the source into a waveguide region where it interacts with one or more features present at a surface of an electrode; and

[0030] (ii) receiving, using a detector, terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region, and processing the reflected and / or transmitted terahertz electromagnetic radiation to determine temporal variations therein, the temporal variations being indicative of one or more dendritic growths occurring at the surface of the electrode.

[0031] The present disclosure provides a sensing device for sensing the structure of an electrode and a method for sensing the structure of an electrode. Generally, a sensing device as described herein monitors the health of a power battery containing an electrode by monitoring the structure of the electrode. Specifically, the sensing device not only operates to monitor the working conditions associated with the battery pack to monitor its health. Alternatively, the sensing device continuously monitors the behavior of the electrodes in the power battery and its internal state over time. Advantageously, monitoring such internal states of the power battery can identify structural irregularities in the electrodes and / or any component of the power battery. In an example, the structural irregularities are caused by the formation of dendrites on the surface of the electrode. In another example, the structural irregularities are caused by the degradation of the electrode (for example, due to the corrosion of the metal present on the surface of the electrode). Subsequently, identifying such structural disorder at the initial stage prevents the occurrence of dangerous events, thereby preventing risks associated with power batteries, such as leakage, exothermic reaction, thermal runaway, multi-battery failure, exhaust, rupture, explosion, fire, short circuit, failure, etc. Advantageously, the sensing device overcomes problems due to the complexity and interdependence of physical and chemical processes in a power battery to predict degradation of a power battery during its operating life due to aging and / or flash accumulation of dendrites during operation. In this regard, the sensing device identifies degradation in capacity, power fade, and safety risks during the operating life of the battery.

[0032] It should be understood that the sensing device (which can implement the method) can be used to sense the structure of any power battery (ie, primary or secondary battery). According to an embodiment of the present disclosure, the sensing device is used to sense the structure of a rechargeable secondary battery.

[0033] Advantageously, the sensing device monitors (i.e., implements the method to monitor) the health of the power battery by identifying an internal state of the power battery, the internal state of the power battery also indicating one or more dendritic growths occurring at the surface of an electrode of the power battery. Specifically, the "internal state" of the power battery refers to the electrochemical structure of the power battery. In this regard, monitoring the internal state of the power battery means monitoring internal components, for example, one or more electrochemical cells comprising the power battery. It should be understood that the electrochemical cell comprises at least one electrode and an electrolyte. Subsequently, the sensing device monitors the health of the power battery based on the detected internal anomalies of the internal state of the power battery. It should be understood that the internal anomaly refers to any deviation in the internal state of the battery due to manufacturing defects, due to physical or chemical changes that occur naturally over time, due to the operating conditions of the power battery, etc., such as structural deviations.

[0034] It should be understood that the sensing devices and methods described herein overcome the shortcomings associated with currently utilized battery management systems that are deployed for analyzing the health of a power battery. It should be understood that a power battery is composed of one or more cells, wherein the cell also includes at least two electrodes. Therefore, the sensing devices and methods are not limited to sensing the structure of a given electrode in a power battery. Alternatively, the sensing device is employed to sense the structure of each cell in each of the one or more cells contained in the power battery. In addition, the sensing device is operable to sense the structure of each of the electrodes of the power battery to analyze the health thereof.

[0035] It should be understood that the sensing device can be implemented to monitor the health of the electrode and / or power battery when the electrode and / or power battery is in situ or in situ and operating. In addition, the sensing device continuously or periodically measures the characteristics of the electrode and / or power battery by using sources and detectors (as discussed in detail later in this article) to monitor its health status, thereby ensuring the safety of operation of the electrode in the appliance in which it is installed.

[0036] Additionally, the sensing device may optionally operate in conjunction with a battery management system (BMS); wherein the sensing device sends to the BMS any important information that may be relevant to indications of poor health or hazardous operation of the electrodes in the appliance.

[0037] In one example, a sensing device is used to monitor the health of a power battery in an in-situ mode of the power battery, wherein the sensing device measures the power battery without removing the power battery from the appliance in which it is installed (e.g., at a service station for electric vehicles). In another case, the sensing device is used to monitor the health of the power battery in a non-in-situ mode of the power battery, wherein the sensing device measures the power battery after the power battery is removed from the appliance in which it is installed. In this regard, the measurements can be made by installing the removed power battery into a maintenance device. In yet another example, the sensing device is used to monitor the health of the power battery in an isolated mode of the power battery. In this regard, the measurements can be made by installing the power battery into a maintenance device, for example, for quality control measurements after the power battery is manufactured. In addition, such measurements related to the power battery can be uploaded to the BMS of the appliance in which the power battery is to be installed.

[0038] Throughout this disclosure, the term "power cell" refers to a device consisting of an electrochemical cell or a group of electrochemical cells, wherein the device is used to generate an electric current, such as to power an electrical device. Optionally, the power cell is charged to provide an electrostatic potential (or a released charge) of electricity. Optionally, the group of electrochemical cells can be arranged in a series configuration, a parallel configuration, or a combination thereof for its operation. Optionally, the power battery houses the group of electrochemical cells and has a housing, electrical connectors, and a control module (e.g., a battery management system) for controlling and protecting the group of electrochemical cells.

[0039] In addition, the term "electrochemical cell" refers to a device that generates electrical energy through a chemical reaction or uses electrical energy to cause a chemical reaction. Typically, an electrochemical cell comprises a positively charged electrode, a negatively charged electrode, and an electrolytic medium for facilitating the flow of charge therein. Examples of electrochemical cells include, but are not limited to, voltaic cells or primary cells, electrolytic cells, primary cells, secondary cells, half cells, and fuel cells.

[0040] Typically, in an operating state of a power battery, where the electrochemical cell of the power battery operates to supply power to a load, the positive terminal of the power battery is referred to as the cathode, and the negative terminal of the power battery is referred to as the anode. It should be understood that the load is an external circuit that consumes power. In such cases, it can be observed that electrons flow from the negative terminal (i.e., the anode) to the positive terminal (i.e., the cathode) via the load. In addition, power batteries are used to power the operation of a large number of electrical devices (such as flashlights, flashlights, toys, remote devices, mobile phones, electric vehicles, laptops, computers, clocks, smart grids, home and commercial buildings, industry, etc.). Optionally, batteries are classified based on the type of electrochemical cell used for their configuration. In such cases, examples of power batteries include, but are not limited to, alkaline batteries, lithium-ion batteries, hydrogen batteries, lead-acid batteries, zinc-air batteries, nickel-metal hydride batteries, aluminum-ion batteries, carbon batteries, flow batteries, glass batteries, magnesium-ion batteries, molten salt batteries, nickel-cadmium batteries, nickel-hydrogen batteries, nickel-iron batteries, nickel-zinc batteries, organic free radical batteries, polymer-based batteries, polysulfide bromide batteries, potassium-ion batteries, sand batteries, silicon-air batteries, silver-zinc batteries, silver-calcium batteries, silver-cadmium batteries, sodium-ion batteries, sodium-sulfur batteries, solid-state batteries, super-iron batteries, super batteries, and zinc-ion batteries.

[0041] The sensing device senses the electrode structure of the power battery when in operation. Throughout this disclosure, the term "electrode" refers to an electrical conductor for establishing contact with the non-metallic part of the electrochemical cell circuit. Optionally, the non-metallic part of the circuit of the electrochemical cell is implemented using an electrolyte, a semiconductor, a vacuum zone, air, etc. According to an embodiment of the present disclosure, an electrode is an electrical conductor that establishes contact between a load (i.e., an external circuit that consumes power) and an electrolyte. In addition, the surface of the electrode is used as a location for electron exchange. Optionally, the surface of the electrode is used as a location for establishing redox equilibrium between the electrode and the electrolyte. It should be understood that the electrode is used as an anode in the first case and as a cathode in the second case. Subsequently, in the first case, the surface of the electrode facilitates oxidation thereon, and in the second case, facilitates reduction thereon.

[0042] It should be understood that the term "electrolyte" refers to a compound that dissociates into ions, thereby allowing electric charge to flow therethrough. It is noteworthy that the electrolyte allows the flow of charge due to the movement of ions therein rather than the flow of electrons. In addition, optionally, the electrodes of the electrochemical cell may also include a catalyst. Typically, the catalyst accelerates the rate of the chemical reaction occurring at the electrode. Examples of catalysts include, but are not limited to, hydrogen peroxide (H2O2), transition metals (such as nickel, vanadium oxide, palladium, platinum, gold, ruthenium, rhodium, iridium, etc.), and light.

[0043] Optionally, the electrodes of the power battery are composed of at least one of the following: metal, metal compound, hydrogen compound, carbon compound, glass. It should be understood that the type of electrode and electrolyte depends on the type of electrochemical cell included in the power battery. In the case of an alkaline power battery, the electrode may be composed of, for example, zinc, zinc oxide (ZnO2) and manganese dioxide (MnO2), and the electrolyte may be composed of, for example, potassium hydroxide (KOH). In the case of a nickel-cadmium power battery, the electrode may be composed of, for example, cadmium oxide (CdO) and nickel (II) hydroxide (NiOOH), and the electrolyte may be composed of, for example, potassium hydroxide (KOH), lithium hydroxide (LiOH) and sodium hydroxide (NaOH). In the case of a lead-acid power battery, the electrode may be composed of lead (Pb) and lead oxide (PbO2), and the electrolyte may be composed of sulfuric acid and water (H2SO4 and H2O).

[0044] Furthermore, in this document, the term "structure" may also refer to irregularities (abnormalities) on the surface of an electrode and / or characteristics of the surface of an electrode.

[0045] In an example implementation of the present disclosure, the sensing device is operable to (i.e., configured to) sense the structure of a power battery, wherein the power battery is implemented by a lithium-ion battery. Subsequently, the lithium-ion battery comprises a plurality of lithium-ion batteries. In such cases, each of the electrochemical cells comprises an electrode (such as a negatively charged electrode and a positively charged electrode), a current collector, a separator, and an electrolytic medium (i.e., an electrolyte) therein. Typically, the negative electrode of a lithium-ion battery is made of carbon, the positive electrode is made of a metal oxide, a polyanion, or a spinel, and the electrolytic medium is composed of a lithium salt in an organic solvent. In the example, the negative electrode (i.e., the anode) is made of graphite carbon, the positive electrode (i.e., the cathode) is made of lithium cobalt oxide (LiCoO2), and the electrolytic medium is composed of a mixture of alkyl carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and lithium hexafluorophosphate (LiPF6) salt. It should be understood that the electrochemical action of the electrode is opposite between the anode and the cathode, depending on the direction of the current flowing through the electrochemical cell.

[0046] The half reaction occurring at the cathode is described as:

[0047] CoO2+Li + +e - <=>LiCoO2

[0048] The half reaction occurring at the anode is described as:

[0049] LiC6<=>C6+Li + +e -

[0050] The complete reaction occurring in a lithium-ion electrochemical cell is then described as:

[0051] LiC6+CoO2<=>C6+LiCoO2

[0052] In addition, optionally, the lithium-ion battery comprises a current collector. Typically, the lithium-ion battery comprises a positive current collector and a negative current collector, such that the positive current collector is attached to the positive electrode and the negative current collector is attached to the negative electrode. Advantageously, the current collector ensures a uniform distribution of charge in the electrode. In addition, the current collector is used as a carrier of the active material in the electrode. Optionally, the positive current collector is composed of aluminum (Al) and the negative current collector is composed of copper (Cu). Advantageously, the use of copper to make the negative current collector prevents the negative electrode from being damaged due to a violent lithium reaction accident.

[0053] In addition, the electrochemical cell comprises a separator between the positive electrode and the negative electrode. The separator allows ions to flow therethrough. It is noteworthy that the separator is composed of a material that is permeable, porous, allows ionic conductivity, provides electrical conductivity, and provides chemical compatibility with the electrolyte. Optionally, the separator is composed of wood, rubber, fiberglass mat, cellulose, polyvinyl chloride (PVC), polyethylene, etc.

[0054] It is worth noting that the anode and cathode of a lithium-ion battery store lithium. In a discharge operating state in which the electrochemical cell is operated to supply power to a load, the electrolyte transports positively charged lithium ions from the anode to the cathode through a separator, and vice versa. The movement of lithium ions generates free electrons in the anode, which results in the generation of charge at the positive current collector to generate current. In addition, the current flows from the positive current collector to the negative current collector through the load to be powered. In a charging operating state, a process completely opposite to the aforementioned process occurs, making the process reversible, and therefore the power battery can be recharged.

[0055] It should be understood that during the operating state, the electrodes of the electrochemical cell undergo decomposition, resulting in the formation of a solid interface layer (SEI) on the surface. The SEI layer is formed due to the decomposition of the electrodes and electrolyte of the battery. Generally, the SEI layer is an electrically insulating and ionically conductive passivation layer. In other words, SEI allows the flow of, for example, lithium ions (Li+), and blocks the flow of electrons in the electrolyte to prevent further decomposition of the electrolyte and ensure continuous electrochemical reactions. It is worth noting that SEI is formed on the surface of the electrode, between the electrode and the electrolyte, acting as a solid electrolyte. Therefore, the SEI layer has an important influence on the performance of the electrode, the battery, and the subsequent power battery. The SEI layer can be analyzed to obtain an understanding related to storage and cycle life, battery capacity, and battery safety in the battery.

[0056] In addition, the surface of the electrode is sensed in order to identify the formation of dendrites thereon. It is noteworthy that dendrites refer to whiskers or prickly protrusions of metal on the surface of the electrode, for example. In the case of lithium-ion batteries, dendrites are thorny protrusions of lithium metal on the surface of the electrode. Optionally, dendrites grow on the surface of the negative electrode (i.e., the anode) of the power battery. Typically, in power batteries, the formation of dendrites on the surface of the electrode can lead to a significant reduction in electrode performance, thereby reducing the efficiency and life of the power battery, while increasing the safety issues associated therewith. Optionally, dendrites growing on the anode of the power battery penetrate the separator between the anode and the cathode, making physical contact with the cathode, thereby causing a short circuit in the power battery, which may further lead to spontaneous combustion therein.

[0057] Therefore, the surface of the electrode is sensed to understand changes in the electrode structure. It should be understood that the structure of the electrode refers to the configuration of the electrode and / or the arrangement of the electrode components. In addition, sensing the structure of the electrode can identify any changes or deviations thereon. It should be understood that the sensing device can be used for routine inspection of power cells. In such cases, there will be no deviations in the surface of the electrode.

[0058] Optionally, changes in the electrode structure are observed due to the formation or establishment of SEI layers, the establishment of dendrites, the dissolution, embedding and peeling of current collectors (e.g., copper, aluminum, etc.), the formation of corrosion layers (e.g., rust-like oxide layers), particle fracture at the electrode, loss of contact between components, etc.

[0059] In addition, one or more layers of the electrode are arranged adjacently in space to provide a waveguide region. Typically, the waveguide region includes the surface of the electrode, and the structure of the electrode changes with the change of the state of charge of the power battery. Specifically, one or more layers of the electrode arranged adjacent to each other in space enable a waveguide region to be formed therebetween. Throughout the present disclosure, the term "waveguide region" refers to a region that guides waves through a path, with minimal energy loss by limiting the expansion of electromagnetic waves in one or two dimensions. Typically, the power of a wave decreases as the distance of the destination from the source increases. Subsequently, it becomes challenging to analyze such waves to gain insight from them, because their power is significantly reduced. Therefore, the waveguide region limits the wave to prevent expansion in different dimensions during its propagation. Optionally, due to total reflection at the wall of the waveguide region, the wave is confined to the inside of the waveguide region. According to an embodiment of the present disclosure, the waveguide region guides electromagnetic waves (i.e., terahertz electromagnetic radiation) from the source to the detector. Typically, terahertz electromagnetic radiation expands into three-dimensional space during propagation. However, the waveguide region limits its such expansion, thereby preventing energy loss.

[0060] According to an embodiment of the present disclosure, the term "state of charge" refers to the polarity of a power battery, wherein the polarity of a power battery defines the direction in which charge flows. Optionally, the state of charge of a power battery may be charging, discharging, or idle. Furthermore, it should be understood that the cause of the change in the electrode structure is not limited to the change in the state of charge of the power battery. Alternatively, the change in the electrode structure may be due to aging, operating environment, etc.

[0061] It is noteworthy that the waveguide region includes the surface of the electrode. Specifically, the waveguide region includes a first layer electrode and a second layer electrode and a separator therebetween. Optionally, the first layer electrode is an anode and the second layer electrode is a cathode. It should be understood that the first layer electrode has a first end and a second end, wherein the second end forms a first wall for separation. Similarly, the first end of the second layer electrode forms a second wall for separation. In such cases, the waveguide region formed including the first layer electrode, the separator and the second layer electrode is sensed to analyze the health of the first layer electrode and the second layer electrode. It should be understood that the first end and the second end of the first layer electrode and the second layer electrode are described with respect to the length or width of the first layer electrode and the second layer electrode. Subsequently, it should be understood that the wave (i.e., the terahertz electromagnetic wave) passing through the waveguide region generally passes through the region between the first end of the first layer electrode and the second end of the second layer electrode. Optionally, the spatial range of the separator between the second end of the first layer electrode and the first end of the second layer electrode is in the range of 25 micrometers (μm) to 100 micrometers (μm).

[0062] Optionally, the waveguide region further comprises at least one of the following: air, dielectric. Specifically, the air or dielectric forms a separation region in the waveguide region. In this regard, the air or dielectric, for example (RTM) can form the surrounding environment of the electrode, thereby containing the waveguide region. Optionally, the waveguide region can contain an electrolyte, a conductive layer (e.g., a layer formed due to dendrites) and / or an insulating layer (e.g., a layer formed due to SEI).

[0063] The one or more layers forming the waveguide region limit the expansion of the wave propagating through the waveguide region. Optionally, the wave propagating through the waveguide region is an electromagnetic wave. In such cases, the electromagnetic field of the electromagnetic wave can propagate through the waveguide in at least one of the following: transverse electric (TE) mode, transverse magnetic (TM) mode, transverse electromagnetic (TEM) mode. Such transverse modes occur due to the boundary conditions imposed on the electromagnetic wave by the one or more layers forming the waveguide region. It is worth noting that in the TE mode, the electric field (or electric flux line) of the electromagnetic field of the electromagnetic wave is perpendicular to the propagation direction of the electromagnetic wave. In the TM mode, the magnetic field (or magnetic field lines) of the electromagnetic field of the electromagnetic wave is perpendicular to the propagation direction of the electromagnetic wave. In addition, in the TEM mode, the electric field of the electromagnetic wave, the magnetic field of the electromagnetic wave and the propagation direction of the electromagnetic wave are perpendicular to each other.

[0064] It is noteworthy that terahertz (THz) electromagnetic radiation is coupled to broadband single modes in circular and / or rectangular metal waveguides, single crystal sapphire fibers and plastic strip planar waveguides for narrowband or terahertz (THz) time-domain spectroscopy applications. In general, sub-picosecond (subps) terahertz (THz) propagation in all types of waveguides has a high group velocity dispersion (GVD), which leads to distortion of the transmitted terahertz (THz) electromagnetic radiation. In addition, for metal waveguides, the group velocity dispersion (GVD) causes excessive broadening of sub-picosecond (subps) terahertz (THz) pulses near the cutoff frequency. However, it should be understood that in the TEM (TM0) mode, for double-wire coplanar lines, coaxial lines or parallel plate metal waveguides that do not have a cutoff frequency, excessive broadening of sub-picosecond (subps) terahertz (THz) pulses will not occur. Advantageously, the use of parallel plate waveguides integrated into the sensing device, such as the parallel electrodes of the manufacturing of a battery, allows the confinement of the TEM mode. Furthermore, the use of parallel-plate waveguides allows sub-picosecond (subps) terahertz (THz) pulses to propagate with minimal losses and distortions.

[0065] In the present disclosure, the use of parallel plate waveguides integrated into the sensing device to allow confinement of TEM modes is referred to as parallel plate waveguide modes (PPWGMs). Optionally, parallel plate waveguide modes (PPWGMs) are achieved by coupling a linearly polarized electric field in a direction perpendicular to the waveguide parallel plate plane, so that only TEM modes exist in the waveguide. In addition, single TEM mode propagation is achieved by selecting an appropriate plate spacing and a uniform incident field pattern with the correct beam size. The uniform incident field pattern avoids coupling of other modes (TM1 and TM2), and therefore, the TEM mode (i.e., TM0) will dominate. For an air-filled waveguide, the cutoff frequency is fcm=mc / 2b, where m=0, 1, 2, ..., and b is the plate spacing. Typically, the lowest order TEM mode (TM0) has no cutoff frequency. In addition, the lowest order TEM mode (TM0) has no group velocity dispersion (GVD) for an ideal conductive plate. Subsequently, propagation losses occur due to the finite conductivity of the metal plate and can be calculated. Furthermore, it will be appreciated that by exploiting the confinement of TEM modes in a parallel plate waveguide of suitable dimensions, changes in the metal plate can be detected with high sensitivity. Furthermore, the composition of changes on the metal plate can be analyzed with very high resolution using Terahertz (THz) time domain spectroscopy.

[0066] Typically, parallel plate waveguide modes (PPWGMs) require a small gap between the parallel plates and an interaction length of several centimeters between the terahertz (THz) electromagnetic field and the material observed between the parallel plates, allowing the recording of a wide, distortion-free time window. The lowest-order TEM mode of the parallel plate waveguide mode (PPWGM) has low propagation losses, limited to the resistive losses in the surface layers of the parallel metal plates. In addition, no low-frequency cutoff occurs in the lowest-order TEM mode. In addition, the propagation of the electromagnetic wave is virtually dispersion-free in the lowest-order TEM mode before the onset of the first higher-order TEM mode. In addition, due to the low mode coupling, if the waveguide is excited in the fundamental mode, distortion-free propagation of the electromagnetic wave is possible even at frequencies above the onset of the first higher-order TEM mode. Subsequently, the spectral features revealed by waveguide spectroscopy are clearer and more defined.

[0067] Optionally, one or more layers of electrodes providing the waveguide region form a parallel plate waveguide. Typically, a parallel plate waveguide refers to a waveguide implemented using two flat conductive plates with a separator between the two flat conductive plates. In operation, the first layer of electrodes and the second layer of electrodes constitute the planar conductive plates of the parallel plate waveguide. Subsequently, the waveguide region comprises the surface of the first layer of electrodes, the surface of the second layer of electrodes and an electrolytic medium therebetween.

[0068] Optionally, the waveguide region provided by one or more layers of electrodes has a minimum spatial range in the range of 225 micrometers (μm) to 300 micrometers (μm). Optionally, the spatial range of the waveguide region is composed of the spatial range of the first layer of electrodes, the spatial range of the second layer of electrodes, and the spatial range of the separator therebetween. Typically, the waveguide region has a minimum spatial range in the range of 225 micrometers (μm) to 300 micrometers (μm) so as to allow electromagnetic waves to propagate through it with less loss. In an example, the first layer of electrodes has a spatial range of 0.125 millimeters (mm), the second layer of electrodes has a spatial range of 0.75 millimeters (mm), and the separator contained therein has a spatial range of 25 micrometers (μm). In such a case, the minimum spatial range of the waveguide region is (125μm+25μm+75μm)225 micrometers (μm). In another example, the first layer of electrodes has a spatial extent of 0.125 millimeters (mm), the second layer of electrodes has a spatial extent of 0.75 millimeters (mm), and the separator contained therein has a spatial extent of 100 micrometers (μm). In such a case, the minimum spatial extent of the waveguide region is (125 μm + 100 μm + 75 μm) 300 micrometers (μm).

[0069] Optionally, the sensing device advantageously employs (and the method advantageously achieves) a parallel plate waveguide mode (PPWGM) of a terahertz (THz) pulse by confining the terahertz (THz) pulse between parallel conducting plates. Optionally, the waveguide is formed by the electrodes of the cell, the separators between the electrodes and the length of the electrodes. Optionally, the waveguide is an integrated part of the sensing device during manufacture, confining the terahertz (THz) pulse. Optionally, a parallel plate waveguide mode (PPWGM) is introduced in the waveguide, resulting in minimal losses and group velocity dispersion (GVD), thereby maintaining the amplitude and shape of the terahertz (THz) pulse when passing through the waveguide. Advantageously, it will be appreciated that controlling the electrode spacing and electrode length to achieve sub-wavelength confinement allows for optimal cell size for the integrated sensing device.

[0070] In addition, the sensing device includes a source of terahertz (THz) electromagnetic radiation. Terahertz electromagnetic radiation refers to electromagnetic radiation with a frequency of 10 12 The source may be a terahertz (THz) electromagnetic radiation source, wherein the frequency of the electromagnetic radiation generated by the at least one source is not limited to 0.1 THz to 30 THz, and thus may include any electromagnetic radiation. Depending on the selected electromagnetic radiation source, the generated radiation may be located in the electromagnetic spectrum between radio waves and infrared waves. Optionally, the wavelength is in the range of 0.1 millimeters (mm) to 1 millimeter (mm). Optionally, the terahertz electromagnetic radiation is essentially non-ionizing and propagates in line of sight (LOS) or non-line of sight (NLOS). Typically, terahertz electromagnetic radiation can penetrate non-conductive materials, has limited penetration of non-conductive semi-solid materials, and cannot penetrate liquids and metals. Subsequently, the terahertz electromagnetic radiation shows limited penetration of the electrolyte passing therethrough. In addition, the terahertz electromagnetic radiation does not penetrate or rarely penetrates non-conductive layers, such as separators and SEI layers. Furthermore, since the terahertz electromagnetic radiation cannot penetrate the metal of the electrode and / or the dendrites on the surface of the electrode, the power of the terahertz electromagnetic radiation is significantly reduced.

[0071] In addition, optionally, the source of terahertz electromagnetic can be a natural source. In such cases, the temperature of the natural source is higher than 10 Kelvin (K). In this regard, the source of terahertz electromagnetic radiation can include the sun, cosmic background radiation from extraterrestrial sources, lightning, discharge, etc. Optionally, terahertz electromagnetic radiation is generated using an artificial source. Examples of artificial sources include, but are not limited to, gyrotrons, backward wave oscillators (BOs), organic gas far-infrared lasers (FIR lasers), Schottky diode multipliers, varactor diode multipliers, quantum cascade lasers (QCLs), free electron lasers (FELs), synchrotron light sources, distributed feedback lasers (DFB) pumped light hybrid crystals, laser time division multiplexing (TDM), pulse sources (such as photoconductors, surface fields, photodiodes, and optical rectification emitters), solid-state sources (such as IMPATT, Gunn, and resonant tunneling diodes), high-temperature superconducting materials, and other semiconductor sources.

[0072] The sensing device includes a coupling device that couples terahertz electromagnetic radiation from a source to a waveguide region, where the terahertz electromagnetic radiation interacts with one or more features present on the surface of the electrode. Generally, a "coupling device" refers to a device that aligns or connects two entities. According to an embodiment of the present disclosure, the coupling device aligns the terahertz electromagnetic radiation from the source to the waveguide region. Optionally, the coupling device changes the incident angle of the terahertz electromagnetic radiation from the source to couple it to the waveguide region. In such a case, the coupling device changes the incident angle of the terahertz electromagnetic radiation relative to the waveguide region at an angle greater than the critical angle. In one example, the coupling device further splits the terahertz electromagnetic radiation to generate multiple beams thereof. In such a case, multiple beams are coupled to each waveguide region in the power battery at the same time. Beneficially, coupling multiple beams of terahertz electromagnetic radiation to each waveguide region in the power battery at the same time saves time and saves power for operating the sensing device. In an example, the coupling device operates so that the terahertz electromagnetic radiation can flood the waveguide region for coupling to the waveguide region. In another example, the coupling device employs a grating device to couple the terahertz electromagnetic radiation to the waveguide region. In yet another example, the coupling device employs an optical element (eg, a focusing lens) to couple the terahertz electromagnetic radiation to the waveguide region.

[0073] Optionally, the coupling device uses a coupling grating. Advantageously, the incident radiation beam of the terahertz electromagnetic radiation is aligned with the coupling grating to enhance the coupling of the terahertz electromagnetic radiation with the waveguide region. Optionally, the coupling device further comprises a secondary grating to prevent the coupling of unwanted electromagnetic radiation to the waveguide region. The secondary grating blocks, refracts and / or reflects the unwanted electromagnetic radiation to prevent its coupling. Furthermore, optionally, in the coupling device, the secondary grating is arranged in a path between the coupling grating and the source.

[0074] Optionally, the coupling device further comprises a focusing lens. Optionally, the focusing lens is composed of silicon. It should be understood that the focusing lens focuses the terahertz electromagnetic radiation from the source to the waveguide region. Optionally, the focusing lens is used to focus the terahertz electromagnetic radiation from the source to the dispersion position of the waveguide region. Optionally, such dispersion position is accurately calculated by the coupling device so that the terahertz electromagnetic radiation can be efficiently propagated in the waveguide region. In one example, the coupling device adjusts the focus of the focusing lens to the dispersion position so that the focusing lens can focus the terahertz electromagnetic radiation at the dispersion position.

[0075] In addition, the terahertz electromagnetic radiation interacts with one or more features present on the surface of the electrode. It should be understood that the terahertz electromagnetic radiation interacts with the one or more features based on its properties. In addition, the one or more features present on the surface of the electrode include, for example, due to reactions within the power cell, the exchange of electrons from the surface of the electrode, the formation of an SEI layer on the surface of the electrode, the formation of dendrites on the surface of the electrode, the breaking or peeling of electrode particles from the surface, and the like. In addition, the terahertz electromagnetic radiation interacts with the one or more features on the surface of the electrode to completely penetrate, partially penetrate, or completely reflect back through the one or more features based on the properties of the one or more features.

[0076] Optionally, the terahertz electromagnetic radiation propagates in the waveguide region as an evanescent wave, and the evanescent wave is confined to a spatial region adjacent to the surface of the electrode. Typically, the terahertz electromagnetic radiation propagates in the waveguide region as an evanescent wave, so that the energy of the evanescent wave is spatially concentrated near the source of the terahertz electromagnetic radiation. Specifically, when the coupling device changes the terahertz electromagnetic radiation to generate a sine wave therefrom, the terahertz electromagnetic radiation propagates as an evanescent wave. In addition, when the sinusoidal terahertz electromagnetic radiation is incident at an angle greater than the critical angle of the waveguide region, total internal reflection is enabled in a spatial region adjacent to the surface of the electrode (typically, from the wall of the waveguide region), and the sinusoidal terahertz electromagnetic radiation is converted into an evanescent wave. It is noteworthy that the intensity of the evanescent wave decays exponentially with increasing distance from the interface formed therewith. It should be understood that due to total internal reflection, during the propagation of the evanescent wave, reflected waves and refracted waves are generated from the evanescent wave. Then, optionally, the reflected wave can be operated to traverse the waveguide area, and the refracted wave is detected by a detector (as discussed in detail later in this article) to analyze the health of the power battery. Optionally, the reflected wave generated after completely traversing the waveguide area is further detected for analyzing the health of the power battery.

[0077] The sensing device includes a detector that receives terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region, and processes the reflected and / or transmitted terahertz electromagnetic radiation to determine time changes therein, the time changes indicating one or more dendritic growths occurring at the surface of the electrode. Throughout the present disclosure, the term "detector" refers to a device or circuit operable to identify and distinguish a specific object or substance. According to an embodiment of the present disclosure, the detector is a device operable to identify terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region. Optionally, the detector also detects evanescent waves refracted from a spatial region of the surface of an adjacent electrode (i.e., the wall of the waveguide region). Examples of detectors include, but are not limited to, direct detectors, heterodyne detectors, Schottky barrier detectors, pair brake detectors, thermal electron mixer detectors, and field effect transistor detectors.

[0078] In one example, the waveguide region is implemented by a parallel plate waveguide, wherein the first layer electrode and the second layer electrode operate as a parallel plate consisting of the waveguide region therebetween. In such a case, the detector may be placed near at least one of: a first end of the first layer electrode forming a first wall of the waveguide region; a second end of the second layer electrode forming a second wall of the waveguide region. In another example, a detector for detecting terahertz electromagnetic radiation reflected by the waveguide region and / or transmitted through the waveguide region is arranged on a transverse axis relative to the axis of the waveguide region.

[0079] It should be understood that the sensing device can operate (and the method can be implemented) during different cycles (e.g., discharge cycles of the battery, charging cycles of the battery) of the life (i.e., state of charge) of the battery. In addition, the sensing device can operate (and the method can be implemented) at different time intervals within the life cycle of the power battery. Subsequently, readings associated with the received terahertz electromagnetic radiation are stored in a memory associated with the detector, the terahertz electromagnetic radiation is reflected and / or transmitted through the waveguide region, and the readings are obtained during different cycle lives such as in the battery and various time intervals within the life cycle of the power battery. In addition, optionally, the detector compares the readings stored in the memory obtained throughout the time with the current readings to generate a health status report of the power battery. In addition, optionally, the detector can also process current readings associated with the received terahertz electromagnetic radiation reflected and / or transmitted through the waveguide region to identify abnormalities caused by the operating conditions of the power battery.

[0080] In addition, the detector processes the terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region to determine time variations therein, which are indicative of one or more dendritic growths occurring at the surface of the electrode. In one example, when the power of the received terahertz electromagnetic radiation reflected and / or transmitted through the waveguide region is significantly reduced, the detector analyzes the degree of absorption of the terahertz electromagnetic radiation by the waveguide region (e.g., in terms of its attenuated power). Subsequently, the detector learns of the presence of a metal layer on the surface of the electrode contained in the waveguide region or the presence of a liquid in the waveguide region. Therefore, detecting such time variations can identify the presence of a metal layer, which may be formed due to one or more dendritic growths (i.e., dendrites) on the surface of the electrode.

[0081] Optionally, the sensing device further comprises a collimating lens to direct the terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region to the detector. Advantageously, the collimating lens prevents scattering of the terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region in an undesired direction and enables parallel propagation. Furthermore, the collimating lens allows a user of the detector or the sensing device to control the field of view, collection efficiency and spatial resolution of the detector, and also enables configuration of the collection angle for efficient collection and sampling of the terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region.

[0082] Optionally, when operating, the source generates terahertz electromagnetic radiation as pulsed radiation, and the detector operates to determine the temporal characteristics of the pulsed radiation that is reflected and / or transmitted to determine the temporal changes therein, which indicate one or more dendritic growths occurring at the surface of the electrode. In such cases, the source of the terahertz electromagnetic radiation may be a pulsed source. Specifically, the pulsed radiation is discontinuous terahertz electromagnetic radiation, in which power appears in pulses of a given duration at a given repetition rate. In other words, the pulsed source generates pulsed terahertz electromagnetic radiation so that the power of the pulsed terahertz electromagnetic radiation occurs in a discontinuous manner at regular time intervals within a given duration. In addition, such pulsed terahertz electromagnetic radiation propagates through the waveguide region and is further received by the detector. Typically, the detector is used to analyze the pulsed terahertz electromagnetic radiation reflected and / or transmitted through the waveguide region to understand its interaction with one or more features of the surface of the electrode. Subsequently, the pulsed terahertz electromagnetic radiation presents a temporal characteristic based on its interaction with one or more features of the surface of the electrode. The detector detects such temporal characteristics of the pulsed terahertz electromagnetic radiation to further determine the temporal changes on the surface of the electrode.

[0083] Optionally, the sensing device further comprises an aperture between the waveguide region and the detector. Typically, the aperture controls the amount of terahertz electromagnetic radiation reaching the detector from the waveguide region. In this aspect, the aperture controls the amplitude of the terahertz electromagnetic radiation reaching the detector. Optionally, the sensing device further comprises a scattering probe. Typically, the scattering probe guides the terahertz electromagnetic radiation reflected and / or transmitted through the waveguide region to the detector. In this aspect, the scattering probe guides the terahertz electromagnetic radiation by, for example, scattering the terahertz electromagnetic radiation at a certain angle.

[0084] In addition, optionally, the sensing device includes a soft pack battery and an optical window, wherein the soft pack battery forms the housing of the power battery. In this regard, the soft pack battery encapsulates the components of the power battery (e.g., one or more electrochemical cells, electrodes, electrolytes, etc.) to provide protection against degradation due to humidity, short circuits, corrosion, temperature, etc. Optionally, such a soft pack battery can be a soft shell in the form of a soft pack, a solid (i.e., hard) shell in the form of a hard unit, or a combination thereof. In an example, the soft pack battery can be manufactured using (one or more) layers of plastic and / or aluminum laminate. In addition, when assembling one or more electrochemical cells or power batteries therein, the soft pack battery is sealed by, for example, heating.

[0085] Beneficially, such pouch cells protect power batteries deployed in various electrical appliances (e.g., electric vehicles, electronic devices, electromechanical appliances, etc.). Specifically, the pouch cells protect the power batteries from mechanical stresses, including deformation and / or tearing that may cause misalignment and / or leakage of electrodes in the power batteries; and thermal stresses that may cause thermal runaway, sparks, short circuits, etc.

[0086] Optionally, the sensing device includes an optical window. Notably, the pouch cell acts as a barrier (i.e., an obstacle) to terahertz electromagnetic radiation due to its conductive properties. Therefore, an optical window, specifically an optically transparent terahertz (THz) window, is employed to allow terahertz electromagnetic radiation from the source to enter via the pouch cell and to exit from the waveguide region in the electrode via the pouch cell.

[0087] Optionally, the first transparent THz window is placed at the bottom of the soft-pack battery encapsulating the power battery. In this aspect, the first transparent THz window is placed between the coupling device and the electrode of the power battery. In addition, the second transparent THz window is placed on the top of the soft-pack battery, wherein the top is the side opposite to the bottom. In this aspect, the second transparent THz window is placed between the electrode of the power battery and the detector. The first transparent THz window couples the terahertz electromagnetic radiation from the source to the waveguide region via the soft-pack battery without any loss. The second transparent THz window collects the terahertz electromagnetic radiation from the waveguide region to the detector via the soft-pack battery without any loss.

[0088] Advantageously, when the electrode (in a power cell) is used by, for example, an electric vehicle (EV), an appliance (i.e., in situ), through the transparent THz window, the sensing device is able to predictively detect and signal any changes in the electrode structure. In addition, when the electrode is operating in hazardous operations, the transparent THz window is able to isolate, remove and contain the electrode, and further reveal the nature of the risk associated with the electrode.

[0089] In addition, optionally, the sensing device can be used for (can implement the method) the second life of the electrode and / or power cell, the conditioning of the recycling electrode and / or power cell, the refurbishment of the electrode and / or power cell. Specifically, the sensing device (the method implemented) provides calibration, alignment baseline and quality control for the electrode (in its "manufactured" state) and / or power cell.

[0090] Furthermore, optionally, observations from the sensing device (implemented method) related to the electrodes and / or power cells may be uploaded to a battery management system of an appliance in which the electrodes and / or power cells are installed.

[0091] In an example implementation of the sensing device, the source and the coupling device are arranged on a transverse axis relative to the axis of the waveguide region. In addition, the detector is arranged on an axis perpendicular to the axis of the waveguide region. In another example implementation of the sensing device, the source, the coupling device, the hole and the detector are arranged on a transverse axis relative to the axis of the waveguide region. In yet another example implementation of the sensing device, the source, the coupling device and the scattering probe are arranged on a transverse axis relative to the axis of the waveguide region. In addition, the detector is tilted at a certain angle on an axis perpendicular to the axis of the waveguide region. It should be understood that various configurations of the arrangement of the components of the sensing device are possible, and subsequently, the sensing device can adopt auxiliary components so that the terahertz electromagnetic radiation from the source can be efficiently propagated to the detector via the waveguide region so as to enable the detector to identify time changes on the surface of the electrode.

[0092] The present disclosure also relates to a method as described above. The various embodiments and modifications disclosed above apply mutatis mutandis to the method.

[0093] The method of the present disclosure is capable of accurately identifying anomalies in the electrode structure, thereby allowing in-situ, in-operation, ex-situ or offline prediction of a power battery. In general, the method as described above can be implemented to monitor the health of a power battery containing electrodes by monitoring the structure of the electrodes. Specifically, the method may not only be implemented to monitor the operating conditions associated with the power battery to monitor its health. Alternatively, the method may be implemented to continuously monitor the behavior of the electrodes in the power battery and their internal state over time. Advantageously, monitoring such internal states of the power battery can identify structural irregularities in the electrodes and / or any component of the power battery.

[0094] Optionally, the terahertz electromagnetic radiation propagates within the waveguide region as an evanescent wave that is confined to a spatial region adjacent to a surface of the electrode.

[0095] Optionally, the method includes generating terahertz electromagnetic radiation as pulsed radiation and receiving the pulsed radiation reflected and / or transmitted through the waveguide region to determine a temporal characteristic of the reflected and / or transmitted pulsed radiation to determine temporal variations therein, the temporal variations indicating one or more dendritic growths occurring at the surface of the electrode.

[0096] Optionally, the method comprises generating terahertz electromagnetic radiation having a frequency in the range of 0.1 terahertz (THz) to 30 terahertz (THz).

[0097] Optionally, the method comprises varying the angle of incidence of terahertz electromagnetic radiation from the source to couple it into the waveguide region.

[0098] Optionally, the waveguide region provided by one or more layers of electrodes has a minimum spatial extent in the range of 225 micrometers (μm) to 300 micrometers (μm).

[0099] Optionally, the method further comprises directing the terahertz electromagnetic radiation reflected and / or transmitted through the waveguide region to a detector using a collimating lens.

[0100] Optionally, the waveguide region further includes any one of the following: air, dielectric.

[0101] Optionally, the electrodes of the power battery are composed of at least one of the following: metal, metal compound, hydrogen compound, carbon compound.

[0102] Optionally, the sensing device comprises a pouch cell and an optical window, wherein the pouch cell forms a housing of a power cell.

[0103] Detailed description of the drawings

[0104] refer to Figure 1, a schematic diagram of a sensing device 100 according to an embodiment of the present disclosure is shown. Notably, the sensing device 100 senses the structure of an electrode 108 of a power battery 106 when in operation. In addition, the electrode 108 is arranged to have one or more layers (depicted as layers 110 and 112) spatially adjacent thereto. The layers 110 and 112 provide a waveguide region 114. It should be understood that the waveguide region 114 includes surfaces (not shown) of the layers 110 and 112, the structures of which change as the state of charge of the battery 106 changes. As shown, the sensing device 100 includes a source 102 of terahertz electromagnetic radiation and a coupling device 104, which couples the terahertz electromagnetic radiation from the source 102 into the waveguide region 114. Specifically, the terahertz electromagnetic radiation interacts with one or more features present on the surfaces of the layers 110 and 112 of the electrode 108. In addition, the sensing device 100 includes a detector 116 that receives terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region 114. In addition, the detector 116 processes the reflected and / or transmitted terahertz electromagnetic radiation to determine temporal changes in the waveguide region 114 that are indicative of one or more dendritic growths occurring at the surfaces of the layers 110 and 112 of the electrode 108.

[0105] Those skilled in the art will appreciate that for the sake of clarity only, Figure 1 A simplified illustration of sensing device 100 is included, which should not unduly limit the scope of the claims herein.Those skilled in the art will recognize many variations, substitutions, and modifications to the embodiments of the disclosure.

[0106] refer to Figure 2A and Figure 2B , showing a schematic diagram of electrodes in a power battery according to different embodiments of the present disclosure. Figure 2A As shown in , the electrode 200A includes a first layer electrode 202, a second layer electrode 206 and a separator 204 therebetween. In the operating state of the electrode 200A, the first layer electrode 202 forms a positively charged electrode (i.e., an anode) and the second layer electrode 206 forms a negatively charged electrode (i.e., a cathode).

[0107] In addition, if Figure 2B As shown in , electrode 200B includes current collectors (depicted as current collectors 208 and 210). In the operating state of electrode 200B, first layer electrode 202 forms an anode, and second layer electrode 206 forms a cathode. In addition, current collector 208 connected to first layer electrode 202 (i.e., anode) is made of copper (Cu), and current collector 210 connected to second layer electrode 206 (i.e., cathode) is made of aluminum (Al).

[0108] Those skilled in the art will appreciate that for the sake of clarity, Figure 2A and Figure 2B This includes a simplified illustration of electrodes 200A and 200B, which should not unduly limit the scope of the claims herein.Those skilled in the art will recognize many variations, substitutions, and modifications to the embodiments of the disclosure.

[0109] refer to Figure 3 , shows a schematic diagram of a sensing device 300 according to an exemplary implementation of the present disclosure. As shown, the sensing device 300 senses the structure of an electrode 302 of a power cell (not shown). The electrode 302 is arranged to have one or more layers (depicted as layer 304 and layer 306) adjacent thereto. In addition, the layer 304 and the layer 306 provide a waveguide region 308, which includes the surfaces of the layer 304 and the layer 306 of the electrode 302. The sensing device 300 includes a source 310 of terahertz electromagnetic radiation and a coupling device 312, which couples the terahertz electromagnetic radiation from the source 310 into the waveguide region 308. In addition, the sensing device includes a detector 314, which receives the terahertz electromagnetic radiation reflected by the waveguide region 308 and / or transmitted through the waveguide region. The detector 314 processes the reflected and / or transmitted terahertz electromagnetic radiation to determine temporal changes therein that are indicative of one or more dendrite growths occurring at the surface of the layer 304 and the layer 306 of the electrode 302. In addition, the sensing device also includes a collimating lens 316 to direct the terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region 308 to the detector 314.

[0110] refer to Figure 4 , a schematic diagram of a sensing device 400 having a soft-pack battery and a transparent terahertz (THz) window according to an embodiment of the present disclosure is shown. As shown, the sensing device 400 is composed of a negative electrode 402, a positive electrode 404. In addition, the soft-pack battery 408 acts as a housing for a power battery (not shown) placed therein. In addition, the sensing device 400 includes a first transparent THz window 406 and a second transparent THz window 410, wherein the first transparent THz window 406 is used to couple the waveguide region in the power battery with a detector (not shown), and the second transparent THz window 410 is used to couple the waveguide region in the power battery with a coupling device of a source (not shown). In addition, the closure 412 in the sensing device 400 is a heat-sealed folded edge, which provides lamination for the battery and the sensing device 400.

[0111] Those skilled in the art will understand that Figure 4 These are merely examples, which should not unduly limit the scope of the claims herein. Those skilled in the art will recognize many variations, substitutions, and modifications to the embodiments of the present disclosure.

[0112] refer to Figure 5 , showing the steps of a method 500 for sensing an electrode structure of a power battery according to an embodiment of the present disclosure. In the method 500 for sensing an electrode structure of a power battery, the electrode is arranged to have one or more layers spatially adjacent thereto, the one or more layers providing a waveguide region including a surface of the electrode, the structure of the electrode changing as the state of charge of the power battery changes. At step 502, a sensing device is used, the sensing device comprising a source of terahertz electromagnetic radiation and a coupling device, the coupling device coupling the terahertz electromagnetic radiation from the source to the waveguide region. Typically, the terahertz electromagnetic radiation interacts with one or more features present on the surface of the electrode. At step 504, a detector is used to receive the terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region. In addition, the detector is used to process the terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region to determine a temporal change therein, the temporal change indicating one or more dendritic growths occurring at the surface of the electrode.

[0113] Step 502 and step 504 are merely illustrative, and other alternatives may be provided in which one or more steps are added, one or more steps are removed, or one or more steps are provided in a different order without departing from the scope of the claims herein.

[0114] Modifications to the embodiments of the present disclosure described above are possible without departing from the scope of the present disclosure as defined by the appended claims. Expressions such as "comprises," "comprising," "containing," "having," and "is" used to describe and claim the present disclosure are intended to be interpreted in a non-exclusive manner, i.e., allowing for the presence of items, components, or elements that are not explicitly described. References to the singular should also be interpreted as involving the plural.

Claims

1. A sensing device for determining temporal changes in the structure of an electrode of an electric power battery, wherein: The power battery comprises: a layer of electrodes, the layers being arranged spatially adjacent to provide a waveguide region comprising a surface of the layers, the structure of the electrodes changing as the state of charge of the power cell changes; a separator between the layers of the electrode, the separator being configured to allow ions to flow therethrough; and a current collector configured to ensure uniform distribution of electrical charge among the layers of the electrode; and Wherein, the sensing device comprises: Sources of terahertz electromagnetic radiation, a detector configured to receive the terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region and to process the reflected and / or transmitted terahertz electromagnetic radiation to determine a temporal variation in the terahertz electromagnetic radiation based on a decrease in power in the received terahertz electromagnetic radiation, and A coupling device, the coupling device is configured to couple the terahertz electromagnetic radiation from the source to the waveguide region, where the terahertz electromagnetic radiation interacts with one or more features present on the surface of the electrode, wherein the source is configured to generate the terahertz electromagnetic radiation as pulsed radiation when in operation, and the detector is configured to determine a temporal characteristic of the reflected and / or transmitted pulsed radiation to determine a temporal variation of the pulsed radiation, the temporal variation being indicative of the one or more dendritic growths occurring at the surface of the electrode.

2. The sensing device according to claim 1, wherein: The source generates the terahertz electromagnetic radiation with a frequency in the range of 0.1 terahertz (THz) to 30 terahertz (THz).

3. The sensing device according to claim 1, wherein: The coupling device is configured to change an angle of incidence of the terahertz electromagnetic radiation from the source to couple the terahertz electromagnetic radiation into the waveguide region.

4. The sensing device according to claim 1, wherein: The waveguide region provided by the one or more layers of the electrode has a minimum spatial extent in the range of 225 micrometers (μm) to 300 micrometers (μm).

5. The sensing device according to claim 1, wherein: The sensing device further comprises a collimating lens for directing the terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region to the detector.

6. The sensing device according to claim 1, wherein: The waveguide region also includes at least one of the following: air, dielectric.

7. The sensing device according to claim 1, wherein: The electrode of the power battery is composed of at least one of the following: a metal, a metal compound, a hydrogen compound, and a carbon compound.

8. The sensing device according to claim 1, wherein: The sensing device includes a pouch cell and an optical window, wherein the pouch cell forms a housing of the power battery.

9. A method of determining temporal changes in the structure of an electrode of an electric power cell, wherein the method comprises: Arranging layers of the electrodes, the layers being spatially adjacent to provide a waveguide region comprising surfaces of the layers, the structure of the electrodes changing as the state of charge of the power cell changes; using a separator between said layers of said electrode to allow ions to flow through said separator; Using current collectors to ensure uniform distribution of electrical charge among the layers of the electrode; as well as using a detector to receive terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region and processing the reflected and / or transmitted terahertz electromagnetic radiation to determine a temporal variation in the terahertz electromagnetic radiation based on a decrease in power of the received terahertz electromagnetic radiation; wherein the method further comprises: using a coupling device to couple the terahertz electromagnetic radiation from a source of the terahertz electromagnetic radiation to the waveguide region, wherein the terahertz electromagnetic radiation interacts with one or more features present on the surface of the electrode, and The method further includes: generating the terahertz electromagnetic radiation as pulsed radiation using the source, and receiving the pulsed radiation reflected and / or transmitted through the waveguide region to determine the temporal characteristics of the reflected and / or transmitted pulsed radiation to determine the temporal variation of the pulsed radiation, wherein the temporal variation indicates the one or more dendritic growths occurring at the surface of the electrode.

10. The method according to claim 9, wherein: The method includes generating the terahertz electromagnetic radiation having a frequency in the range of 0.1 terahertz (THz) to 30 terahertz (THz).

11. The method according to claim 9, wherein: The method includes varying an angle of incidence of the terahertz electromagnetic radiation from the source to couple the terahertz electromagnetic radiation into the waveguide region.

12. The method according to claim 9, wherein: The waveguide region provided by the one or more layers of the electrode has a minimum spatial extent in the range of 225 micrometers (μm) to 300 micrometers (μm).

13. The method according to claim 9, wherein: The method further comprises directing the terahertz electromagnetic radiation reflected by and / or transmitted through the waveguide region to the detector using a collimating lens.

14. The method according to claim 9, wherein: The waveguide region also includes any of the following: air, dielectric.

15. The method according to claim 9, wherein: The electrode of the power battery is composed of at least one of the following: a metal, a metal compound, a hydrogen compound, and a carbon compound.

16. The method according to claim 9, wherein: The method is implemented using a sensing device comprising a pouch cell and an optical window, wherein the pouch cell forms a housing for the power cell.

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