Apparatus and method for monitoring electrolyte of battery

Abstract

Disclosed is an apparatus and a method for monitoring parameters associated with an electrolyte sample of a battery, the apparatus comprising: a metallic housing with at least one opening; at least one access window, wherein the at least one access window is disposed on the battery via at least one opening of the metallic housing, wherein the at least one access window includes or is in contact with an electrolyte sample whose parameters are monitored, wherein the at least one access window is transparent to electromagnetic radiation, and wherein the parameters are monitored based on characteristics electromagnetic radiation emanating from the at least one access window; and a polymeric layer functioning as an insulator that insulates the battery from the metallic housing and the at least one access window, wherein the metallic housing is disposed on the polymeric layer, and wherein a portion of the at least one access window is disposed on the polymeric layer.

Description

[0001] APPARATUS AND METHOD FOR MONITORING ELECTROLYTE OF

[0002] BATTERY

[0003] TECHNICAL FIELD

[0004] The present disclosure relates to monitoring and measurement of battery parameters. The present disclosure also relates to an apparatus and a method for monitoring transport and thermodynamic parameters of an electrolyte sample included in a battery or cell assemblies.

[0005] BACKGROUND

[0006] Battery performance highly depends on transport and thermodynamic parameters of an electrolyte of a battery. For instance, in lithium-ion batteries, uniformity of lithium plating and formation and propagation of dendrites depend on the parameters of the electrolyte. Furthermore, based on the parameters, it may be possible to determine capacity, condition, and lifetime of the battery. Thus, measurement of the transport parameters and the thermodynamic parameters may allow battery manufacturers to model the battery and estimate the performance of the battery, perform real-time monitoring of the parameters, and identify indications of degradation and failure prior to their occurrence. However, the measurement of the transport and thermodynamic parameters may not be straightforward and obtaining accurate measurement may be highly challenging. Currently, multi-tool- based measurement techniques are employed for measuring the parameters. Additionally, the measurement of the parameters necessitates assuming certain conditions in which the parameters are to be measured. This affects the accuracy of the measured parameters.

[0007] The multi-tool measurement techniques have certain bottlenecks such as requirement of large volumes of the electrolyte and impracticality in terms of determining or monitoring whether the battery is safe to use. To ensure that the measurements have a practical application, smart sensors have been developed and incorporated into battery cells for monitoring the parameters of the electrolyte. For example, optical fibre grating sensors may sense electrolyte decomposition and luminescent probe sensors may measure electrolyte salt concentration. However, such fibre sensors are invasive and lead to added stress within the battery. Furthermore, implantation of the sensors requires consideration of positioning and sealing, which may disintegrate under operational conditions.

[0008] Additionally, a common challenge across flow battery technologies is the change in cell potential associated with variations in electrolyte concentration during operation. These concentration changes can degrade capacity over time and necessitate maintenance actions such as chemical replenishment. This degradation affects battery capacity and performance, and the electrolyte may require refreshing. Accurate and timely monitoring of electrolyte composition is therefore essential to prevent performance degradation and extend operational life. Traditional methods of monitoring, such as open-circuit voltage, potentiometric titration or UV-Vis spectroscopy, have limitations in terms of practicality, sensitivity, or in-line applicability, particularly for the highly absorbing positive electrolyte used in flow batteries.

[0009] Therefore, there exists a need to provide an apparatus and a method that allows monitoring and measuring parameters of electrolyte solutions while overcoming the aforementioned drawbacks.

[0010] SUMMARY

[0011] The aim of the present disclosure is to provide an apparatus, a battery management system (BMS), and a method for monitoring transport and thermodynamic parameters of an electrolyte sample included in a battery or cell assemblies. The apparatus includes an access window that work in cooperation with an electrolyte sample whose parameters are required to be measured or monitored. The access window may be irradiated by an electromagnetic radiation (i.e., an electric field), which may be in Terahertz frequency range (for example 0.1-10 THz) or in any other range in the electromagnetic spectrum. For example, the frequency range of the electromagnetic radiation may lie between radio waves and infrared waves. The electromagnetic radiation may be scattered by the electrolyte sample and reemerge from the access window. Based on characteristics of electromagnetic radiation emerging from the access window, the transport and thermodynamic parameters of the electrolyte sample may be determined. The aim of the present disclosure is achieved by the provided apparatus, the battery management system, and the method for monitoring transport and thermodynamic parameters of the electrolyte sample as defined in the appended independent claims to which reference is made. Advantageous features are set out in the appended dependent claims.

[0012] Throughout the description and claims of this specification, the words "comprise" , "include", "have", and "contain" and variations of these words, for example "comprising" and "comprises" , mean "including but not limited to" , and do not exclude other components, items, integers, or steps not explicitly disclosed also to be present. Moreover, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0013] BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 illustrates an exemplary side-view of an apparatus for monitoring transport and thermodynamic parameters of an electrolyte sample, in accordance with an embodiment of the present disclosure; FIG. 2 illustrates an exemplary top-view of the apparatus for monitoring transport and thermodynamic parameters of the electrolyte sample, in accordance with an embodiment of the present disclosure;

[0015] FIG. 3 depicts steps of a method for monitoring transport and thermodynamic parameters of the electrolyte sample, in accordance with an embodiment of the present disclosure; and

[0016] FIG. 4 illustrates an exemplary placement of an access window on a topsurface of a pouch battery, in accordance with an embodiment of the present disclosure.

[0017] DETAILED DESCRIPTION OF EMBODIMENTS

[0018] The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practising the present disclosure are also possible.

[0019] In a first aspect, the present disclosure provides an apparatus for monitoring parameters associated with an electrolyte sample of a battery, the apparatus comprising: a housing with at least one opening; and at least one access window, wherein the at least one access window is disposed on the battery via at least one opening of the housing, wherein the at least one access window includes or is in contact with an electrolyte sample whose parameters are monitored, wherein the at least one access window is transparent to electromagnetic radiation for example of a Terahertz frequency, and wherein characteristics of the electromagnetic radiation is selected according to the parameters to be monitored.

[0020] In a second aspect, the present disclosure provides a battery management system for monitoring parameters associated with an electrolyte sample, the battery management system comprising: a battery comprising a set of electrodes and an electrolyte sample; and at least one access window, wherein the at least one access window is disposed on the battery via at least one opening of a housing, wherein the at least one access window includes or is in contact with the electrolyte sample whose parameters are to be monitored, wherein the at least one access window is transparent to the electromagnetic radiation, and wherein the parameters are monitored based on characteristics of the electromagnetic radiation emanating from the at least one access window.

[0021] In a third aspect, the present disclosure provides a method for monitoring parameters associated with an electrolyte sample of a battery, the method comprising : irradiating a prism with a first electromagnetic radiation, wherein the first electromagnetic radiation propagates through the prism and gets scattered at an edge of at least one access window, wherein the edge of the at least one access window is integrated to the prism and is transparent to the first electromagnetic radiation, wherein the at least one access window includes or is in contact with the electrolyte sample whose parameters are monitored, and wherein the first electromagnetic radiation gets scattered upon interacting with the electrolyte sample in the at least one access window; detecting a second electromagnetic radiation emanating from the prism, wherein scattered electromagnetic radiation re-enters the prism and emanates from the prism as the second electromagnetic radiation; measuring one or more characteristic features of the second electromagnetic radiation; and monitoring a set of parameters of the electrolyte sample based on the one or more characteristic features.

[0022] Optionally, the electromagnetic radiation may be of Terahertz frequency. However, the frequency of the electromagnetic radiation may not be limited to Terahertz frequency range (such as 0.1 THz to 30 THz) and, therefore, the frequency range of the electromagnetic radiation may lie in any other range within the electromagnetic spectrum. Depending on a source of electromagnetic radiation selected, for generating the electromagnetic radiation, the frequency range of the electromagnetic radiation may lie between radio wave frequencies and infrared wave frequencies.

[0023] The present disclosure provides the aforementioned first aspect, the aforementioned second aspect, and the aforementioned third aspect, to monitor transport (such as conductivity, ionic concentration, ionic diffusion coefficients, or transference number) and thermodynamic parameters (such as molar thermodynamic factor) of an electrolyte sample. The electrolyte sample may be part of a battery. The electrolyte sample may be enclosed by one or more access windows that are in contact with the battery or the cell assembly (such as Lithium-ion cells / batteries, next generation solid state cells / batteries, redox flow cells / batteries, etc). The monitoring of the transport and thermodynamic parameters is non-invasive and non-destructive. The monitoring involves determining values of the transport and thermodynamic parameters of the electrolyte sample of the battery or cell assembly. The monitoring further involves predicting health and safety associated with usage of the battery based on the monitoring of the determined parameters of the electrolyte sample.

[0024] The parameters of the electrolyte sample may be determined by use of THz (Terahertz) spectroscopy in a non-invasive manner. In accordance with an embodiment, one or more access windows facilitate obtaining THz Attenuate Total Reflection (ATR) measurements for monitoring batteries and fully assembled cells, regardless of whether the cells / batteries are in-situ, in-operando, or off-line, for checking condition and extent of degradation of the cells / batteries. The transport and thermodynamic parameters may be obtained from optical properties of the electrolyte sample measured by THz spectroscopy. Each access window may absorb a portion of electromagnetic radiation of THz frequency range (for example, frequency range 0.1-10 THz). Transmitted electromagnetic radiation may get scattered inside the access window due to the electrolyte sample and may re-emerge from the access window. Based on characteristics (such as amplitude, phase, and so on) of the remerged electromagnetic radiation of THz frequency range, the transport and thermodynamic parameters of the electrolyte sample may be determined. Based on monitoring of the determined parameters, alerts may be generated to indicate a state of health of a cell / battery and whether the cell / battery is safe to use, and a lifetime of the cell / battery can be predicted.

[0025] In accordance with an embodiment, the electrolyte sample (for example, a Lithium (Li)-ion liquid electrolyte) may be a strong absorbent and, therefore, allow the electromagnetic radiation (in THz frequency range) to get absorbed into the electrolyte sample via the access window. Based on the monitored parameters of the electrolyte sample, potential issues in the cell / battery (such as reduced capacity, reduced lifetime, degradation, formation of Li-plating and dendrite formation, and so on), that may lead to a failure of the cell / battery, can be predicted. Thus, based on the monitoring, earliest indications of potential failure may be obtained, and the battery management system may be alerted. For example, a generated alert could be "excessive electrolyte degradation".

[0026] Optionally, the electrolyte sample may be a vanadium-based electrolyte, for example, in a Vanadium Redox Flow Battery (VRFB) or other flow batteries, which is known to have higher energy density compared to other flow battery chemistries. In such systems, vanadium salts are dissolved in aqueous sulphuric acid and stored in separate positive and negative electrolyte tanks, where the electrolytes are circulated continuously by pumps. In a typical VRFB system, vanadium exists in four oxidation states (V2+, V3+, V4+, and V5+), where the initial solution in both electrolyte tanks contain a mixture of V3+and V4+in equal concentrations. During charge and discharge cycles, the redox couples V4+ / V5+and V2+ / V3+are formed in the positive and negative electrolytes, respectively, as oxidation and reduction reactions occur simultaneously in each halfcell of the battery. In accordance with embodiments of the present disclosure, a sample of this vanadium-based electrolyte is monitored non- invasively through the access window using spectroscopy (such as THz ATR), allowing monitored parameters to be determined in real-time within the operating system (for example, a VRFB system).

[0027] The parameters to be monitored may include at least one of: an Average Oxidation State (AOS), a State of Charge (SoC), and a percentage concentration, for example V2+, V3+, V4+, or V5+, within the electrolyte. Each of these parameters are dependent on the chemical composition and concentration of the electrolyte sample. Monitoring these parameters enables assessment of electrolyte condition, degradation, and imbalances between the tanks of a flow battery.

[0028] Optionally, the flow battery may consist of, but is not limited to, a Vanadium Redox Flow Battery (VRFB), an Iron-Chromium flow battery, a Zinc-Bromine flow battery, a Zinc-Iodine system, or other redox flow battery systems.

[0029] Over time, the concentration of species, for example of vanadium species, may change, resulting in a deviation from the nominal operating conditions. This degradation affects battery capacity and performance, and the electrolyte may require refreshing. While the electrolytes can nominally remain in use for up to ten years, performance may degrade due to imbalance in the ionic species. The extent of degradation may be assessed by monitoring the AOS, which represents the average oxidation number of species such as vanadium in the electrolyte. For example, if the electrolyte consists of 50% V3+and 50% V4+, where the numbers 3 and 4 are the oxidation state numbers, the AOS is calculated as:

[0030] AOS = (%V3+ x 3 + %V4+ x 4) / (%V3++ %V4+)

[0031] AOS = (50% x 3 + 50% x 4) / (50%+ 50%)

[0032] AOS = (1.5 + 2 ) / 1= 3.5

[0033] As the battery cycles over time, the AOS may drift above 3.5, resulting in capacity loss and potential system failure. While periodic monitoring and remixing of electrolytes may partially recover performance, flow battery systems, for example VRFBs, are subject to asymmetrical loss mechanisms (for example, precipitation in the catholyte and oxidation in the anolyte, and gassing reactions at the positive and negative electrodes) that make simple remixing ineffective. Manual monitoring of the negative electrolyte is currently undertaken by on-site personnel, as existing methods such as open-circuit voltage, potentiometric titration, or UV-Vis spectroscopy are either impractical or inadequate, especially for the highly absorbing positive electrolyte. Accordingly, the present disclosure enables monitoring (for example, in-situ and in-operando) of AOS shifts through the radiation measurements across the access window positioned in the electrolyte piping of flow batteries, facilitating early detection of redox imbalance and degradation while enabling the battery management system to respond dynamically.

[0034] The electrolyte sample in a VR.FB, or any other flow battery, system may be monitored in-line using optical spectroscopy techniques such as Terahertz Time Domain Spectroscopy (THz TDS), where a THz pulse probes the intermolecular vibrations of a material to produce a unique signature of its chemical constituents. Another spectroscopy method uses laser probing spectroscopy to detect changes in the optical properties of light emitted by the molecules of a material. The radiation, THz ATR, can be applied to dynamic liquids, (e.g. electrolytes being circulated in the positive and negative electrolyte tanks), therefore continuous monitoring of the electrolyte concentration could potentially reveal detailed information regarding the depletion and degradation of its constituents. A prior calibration may be performed, wherein the state-of-charge (SoC), temperature, and electrolyte concentrations are varied systematically, and the corresponding THz spectra recorded. Variations in the spectral peaks, positions or areas under the peaks may reflect underlying thermodynamic and transport parameters. From the optical parameters (for example, absorption, refractive index, and complex permittivity), the concentration of vanadium species may be determined, and AOS may be computed in real-time. The resulting AOS may then be compared with the recorded reference values. Where deviations occur, alerts may be issued by the battery management system. For example, an alert message could be "AOS > +3.5" or "Low Vx+concentration", where x = 2, 3, 4 or 5. In accordance with embodiments of the present disclosure, the apparatus and method allow non-invasive, real-time monitoring of parameters of the electrolyte sample through the access window.

[0035] Throughout the operational life of the flow battery, for example VRFB, the SoC, concentration, and AOS measurements may be monitored continuously and stored in a cloud-based battery passport. This provides remote, real-time electrolyte health monitoring and allows automatic electrolyte rebalancing actions to be taken as necessary. Such monitoring improves potential issues in the cell / battery (such as reduced capacity, reduced lifetime, degradation, and so on). Optionally, the THz TDS instrumentation (including, but not limited to, THz ATR), will be modified to demonstrate an in-line monitoring system, which may be constructed using off-the-shelf optical components, facilitating cost-effective implementation. The optical spectroscopy monitoring may take place through the access window situated on the pipe that carries the electrolyte sample. As a result, manufacturers may integrate this monitoring solution into commercial battery stacks, improving maintenance efficiency and accelerating the adoption of large- scale energy storage systems.

[0036] Optionally, where THz methods are not effective (for example, in highly absorbing positive electrolytes), laser-based optical spectroscopy will be used. A laser source may excite the monitored electrolyte (for example, vanadium) molecules, and variations in the emitted or scattered light may be captured and analysed. These spectral changes may be associated with changes in electrolyte concentration, allowing AOS to be inferred by comparison with previously measured optical measurements. The variation in concentration of the electrolyte during charging and discharging may also reveal "concentration swing" behaviour, which is a contributor to capacity fade. The term "concentration swing", in flow batteries, refers to the change in concentration of the active species within the electrolyte solutions as they undergo charging and discharging cycles. This swing is essential for storing and releasing energy efficiently. During charging, the active species are oxidized or reduced, leading to a change in concentration in the respective electrolyte solutions. Conversely, during discharging, the opposite occurs. The swing can be gradually decreasing concentration from 1 M, eventually to 0.1 M over time. In accordance with embodiments of the present disclosure, concentration swing behaviour may be monitored non-invasively through the access window using optical spectroscopy, allowing detection of changes in electrolyte composition over time. The apparatus includes the housing. The housing may be metallic (which is preferred for prismatic and cylindrical batteries), a layer of aluminum on a polymer (which is preferred for pouch cell), or polymeric (which is preferred for flow batteries). The apparatus further includes the at least one access window. The window is constituted of a material that is transparent to electromagnetic radiation and compatible (for example chemically resistant) to electromagnetic radiation of THz frequency range. Furthermore, the housing may be lightweight and have a high thermal conductivity. A lightweight material is one with low density that minimizes the overall mass of the battery system (for example, aluminum, magnesium, or polymer composites). A material with high thermal conductivity is one that efficiently transfers heat away from the battery components to prevent overheating and maintain performance (for example, copper, aluminum, or thermally conductive polymer composites). The housing therefore is preferably made of a lightweight, conductive material which must be transparent to electromagnetic radiation. For example, a metallic material or a polymeric material, typically a polymeric composite, that provides sufficient conductivity, which is preferably about at least 50% of the conductivity of stainless steel. The housing may be made of one of: aluminum (Al), an aluminum alloy, or a steel alloy. The housing may mechanically support a battery. In accordance with an embodiment, the battery may include an anode layer, a separator layer, and a cathode layer. The separator layer may be positioned between the anode layer and the cathode layer, which prevents direct electrical contact between the electrodes and avoids short circuits while allowing ionic conduction within the battery. Thereafter, the anode, separator, and cathode layers may be rolled to form a cylindrical structure. The metallic housing may enclose the cylindrical structure (i.e., the battery). In some embodiments, the anode layer, the separator layer, and the cathode layer may form a pouch battery or a prismatic battery. The metallic housing includes the at least one opening of a certain dimension. The dimension of the at least one opening is related to or based on a dimension of at least one access window. The dimension of the at least one opening may be such that the at least one access window is deposited on the at least one opening of the metallic housing. The access window may be disposed on one of the surfaces of the metallic housing.

[0037] Optionally, the apparatus further includes a polymeric layer functioning as an insulator. If the housing is a metallic housing, the polymeric layer insulates the battery from the metallic housing and the at least one access window, preventing electrical short circuits. The metallic housing is disposed on the polymeric layer. A portion of the at least one access window may be disposed on the polymeric layer. Optionally, if the housing is a non-metallic or polymeric housing, the polymeric layer may be included to provide mechanical support, thermal insulation, or chemical resistance, as required by the structural or operational characteristics of the battery system.

[0038] The at least one access window is transparent to THz frequency radiation (i.e., at least one access window is THz compatible). The at least one access window allows electromagnetic radiation of THz frequency range to penetrate through the at least one access window. Furthermore, the at least one access window may be required to allow the electromagnetic radiation to penetrate the at least one access window without attenuating (or minimally attenuating) the electromagnetic radiation. In accordance with an embodiment, edges of each access window may be sealed. Each access window may be constituted of one or more components that are THz compatible. Optionally, the one or more components of each access window may include at least one of silicon (Si), polytetrafluoroethylene (PTFE / (C2F4)n), and polymethyl pentene (PMP / TPX / (CeHi2)n).

[0039] The at least one access window includes or is in contact with the electrolyte sample whose transport and thermodynamic parameters may be required to be monitored. In accordance with an embodiment, the cylindrical structure (i.e., the battery) may be soaked in the electrolyte sample and the access window may be positioned on the top surface or the bottom surface of the cylindrical structure that is exposed (i.e., not enclosed by the metallic housing). An optimal placement of the at least one access window is such that the at least one access window does not obstruct normal operation of the battery or the environment in which the at least one access window is embedded.

[0040] The positioning of the access window on the exposed surfaces (i.e., top surface or the bottom surface) allows monitoring of the transport and thermodynamic parameters by probing a cross section of the anodeseparator-cathode layers and the electrolyte sample with electromagnetic radiation of THz frequency range. The anode layer-separator layercathode layer structure may present itself as a multilayer parallel plate waveguide input port to an incident electromagnetic radiation of THz frequency range. The probing of the cross section of the anode-separator- cathode layers and coupling of the incident electromagnetic radiation depends on attenuation characteristic of the electrolyte sample.

[0041] Optionally, the monitored parameters include at least one of conductivity, ionic diffusion coefficients, an ionic concentration, a molar thermodynamic factor, and a transference number. Each of the monitored parameters are dependent on a concentration of the electrolyte sample. The monitored parameters may provide a detailed insight on the interfacial kinetics of the battery and the transport state of the battery and the thermodynamic state of the battery. The monitoring is nondestructive and is determined based on optical properties of the electrolyte sample. For example, if the battery is a Li-ion battery, the monitored parameters may include Li-ion diffusion coefficients and Li-ion concentration. In accordance with an embodiment, both the transport parameters and the thermodynamic parameters are determined for varying concentrations of the electrolyte sample in varying conditions (such as differing temperature conditions).

[0042] In accordance with an embodiment, the one or more components of the at least one access window may be required to be compatible to the chemistry of the electrolyte sample (which can be liquid-based, solidbased, or gel-based). The electrolyte sample may be aqueous acidic, aqueous neutral or substantially neutral, or aqueous alkaline. Optionally, the one or more components of the at least one access window may be compatible to the chemistry of the electrolyte sample. The electrolyte sample is one or more of lithium (Li)-hexafluorophosphate (LiPFe), lithium (Li)-tetrafluoroborate (UBF4), lithium (Li)-perchlorate (IJCIO4), lithium Bis(fluorosulfonyl)imide LiN(SO2F)2, lithium oxide (U2O), lithium sulfide (IJ2S), polyethylene oxide (PEO / C2nH4n+2On+i), 0-alumina, polyvinylidene fluoride (PVDF / (C2H2F2)n), magnesium bis(trifluoromethylsulfonyl)imide (Mg(N(CF3SO2)2)2), lithium phosphate (U3PO4), lithium phosphorous oxynitride (LiPON / LisPC N), polyvinylidene fluoride-co- hexafluoropropylene (PVdF-HFP), lithium borosilicate glass, sodium sulfide (Na2S), lithium nitride (U3N), sodium superionic conductor (NaSICON), lithium superionic conductor (LiSICON), polyvinyl alcohol (PVA / (C2H4O)X), lithium phosphorous sulfide (LPS), polyacrylamide (PAA / (C3HsNO)n), lithium lanthanum zirconium oxide (LLZO / Li?La3Zr2Oi2), lithium sulfide-phosphorus pentasulfide (U2S-P2S5), lithium phosphorus sulfide (U3PS4), lithium aluminum titanium phosphate (LATP / Lii+xAlxTi2-x(PO4)3), lithium lanthanum titanium oxide (Perovskite LLTO / Lio.ssLao.seTiOs), lithium germanium phosphorus sulfide (LG- PS / LiioGeP2Si2), Argyrodite (LePSsX / X = Cl, Br, or I), thio-lithium super ionic conductor (Thio-LiSICON / LiioGeP2Si2), lithium phosphorus sulfide (LPS / IJ3PS4), zinc-bromine (Zn-BR) all-iron (All-Fe), zinc-air (Zn / Air), zinc-vanadium (Zn / V), zinc-cerium (Zn / Ce), iron-chromium (Fe-Cr), allvanadium (All-V), all-lead (All-Pb), vanadium-bromine (V-Br), or sodiumbromine (S-BR). The electrolyte sample may be dissolved in a solvent. In an embodiment, the electrolyte sample may be dissolved in one of ethylene carbonate (EC or (CH2O)2CO), diethyl carbonate (DEC or OC(OCH2CH3)2), dimethyl carbonate (DMC or OC(OCH3)2), or ethyl methyl carbonate (EMC or C4H8O3). Based on a choice of the electrolyte sample and the solvent, the one or more components of the at least one access window may be selected. Conversely, based on a choice of the one or more components of the at least one access window, the electrolyte sample and the solvent may be selected. The selections are required to be such that the one or more components of the at least one access window are compatible to the chemistry of the electrolyte sample.

[0043] The polymeric layer functions as the insulating layer in which the battery (i.e., the cylindrical structure composed of the anode layer-separator layer-cathode layer) may be encased. Specifically, the polymeric layer may encase the exposed surfaces, i.e., the top surface and / or the bottom surface of the cylindrical structure, which is not encased by the metallic housing. The polymeric layer is constituted of an insulating polymer and functions as an encapsulating polymer. Furthermore, the insulating polymer is compatible to the electromagnetic radiation of THz frequency (i.e., frequency range 0.1-10 THz). Optionally, the polymeric layer may be constituted of one or more of polyimide (PI), synthetic polymers composed of polyamide such as nylon, polypropylene (PP or (C3He)n), or polyethylene terephthalate (PET or (CioHsO^n).

[0044] The positioning of the polymeric layer of the apparatus may be such that the polymeric layer insulates the exposed surfaces, i.e., the cross section of the anode-separator-cathode layers, of the cylindrical structure (i.e., battery) from the metallic housing. The insulation prevents creation of a short circuit between electrode edges (i.e., edges of the anode layer and the cathode layer constituting the exposed surfaces) and the metallic housing. Furthermore, a portion of each access window is disposed on the polymeric layer. The remaining portions of each access window may be disposed on the at least one opening of the metallic housing. In some embodiments, the polymeric layer is soaked with the electrolyte sample.

[0045] Optionally, the battery or cell (i.e., the exposed surfaces of the cylindrical structure or the cross section of the anode-separator-cathode layers) is encased on a first surface of the polymeric layer. The metallic housing and the at least one access window (i.e., a portion of the at least one access window) are disposed on a second surface of the polymeric layer. The second surface is opposite to the first surface. The polymeric layer may be of a predefined width such that the first surface is separated from the second surface by a predefined distance. Thus, the polymeric layer functions as a dielectric barrier between the metallic housing (disposed on the second surface of the polymeric layer) and the battery (disposed on the first surface of the polymeric layer). Additionally, the polymeric layer functions as a dielectric barrier between the at least one access window (disposed on the second surface of the polymeric layer) and the battery (disposed on the first surface of the polymeric layer).

[0046] In accordance with an embodiment, the apparatus is designed such that the placement of the at least one access window does not lead to an introduction of any mechanical stress to any part / portion of the battery. The one or more materials constituting each of the apparatus components (i.e., the metallic housing (Al), the access window (Si, PMP, or PTFE), and the polymeric layer (PI, PET, PP) are robust and stable. This ensures that the apparatus does not introduce a safety hazard that may lead to a short circuit, disconnection, thermal runaway, and so on, in dynamic operating environments when subjected to vibrational forces. Furthermore, the one or more materials, constituting the components of the apparatus, are corrosion-proof. Hence the components do not corrode over time or reduce the performance of the battery. The metal that constitutes the metallic housing does not react with the electrolyte sample. This allows avoiding corrosion and potential performance degradation of the battery. The one or more components of the at least one access window may fill the at least one opening of the metallic housing and seal the metallic housing to avoid leakage of the electrolyte sample.

[0047] The present disclosure also relates to the second aspect as described above. Various embodiments and variants disclosed above, with respect to the aforementioned first aspect, apply mutatis mutandis to the second aspect.

[0048] The battery management system of the present invention refers to an electronic system that manages (monitors, balances, manages) packs of batteries. The battery management system comprises the battery / cell assembly and the at least one access window. The battery includes a set of electrodes and the electrolyte sample. The set of electrodes may include a cathode and an anode. The set of electrodes undergo oxidation and reduction reactions during charging and discharging cycles of the battery. The electrolyte sample, dissolved in a solvent, facilitates transfer of ions between the set of electrodes during the charging and discharging cycles of the battery. In accordance with an embodiment, the battery may be constructed as a sandwich of anode layers, separator layers, and cathode layers. The sandwich may be positioned within an enclosure (i.e., the housing) that is filled with the electrolyte sample. Based on a shape of the housing, a configuration of the sandwich may be prismatic, pouch, or cylindrical. The housing may be metallic for prismatic and cylindrical cells. The housing may be constituted of an aluminum layer on a polymer for pouch cells. For flow batteries, the housing is polymeric (such as a plastic pipe). In flow batteries wherein, the access window may be placed in the polymeric (plastic) pipe.

[0049] The at least one access window is disposed on the at least one opening of the housing (i.e., the enclosure or housing) that houses the battery (i.e., the anode layers and the cathode layers separated by the separator layers). The edges of each access window may be sealed. If the housing is a metallic housing (for prismatic and cylindrical cells), a portion of the at least one access window and the metallic housing are disposed on a surface of the polymeric layer functioning as an insulator. The polymeric layer insulates the battery (i.e., the top and / or bottom surfaces of the cylindrical structure or cross section / edges of the anode-separator- cathode layers) from the metallic housing and the at least one access window. The polymeric layer is constituted of an encapsulating polymer that encases the battery.

[0050] In flow batteries, the at least one access window may be situated on plastic pipes that carry the electrolyte sample. The plastic pipes may be constituted of one or more of thermoplastic resin that does not react with the electrolytic solution, for example, polyethylene resin (PE), polypropylene resin (PP), or polyvinyl chloride resin (PVC). Unlike Li-ion batteries, in the flow battery access window housing of the present invention is preferably non-metallic and thermoplastic. Depending on the compatibility with the radiation (for example THz) of the measurement side of the access window material with the electrolyte, an additional polymer layer may be added for screening from the electrolyte.

[0051] The at least one access window may include the electrolyte sample whose transport parameters and thermodynamic parameters may be monitored. The at least one access window facilitates optical and non-destructive (non-invasive) monitoring of the transport and thermodynamic parameters (based on measurement of optical properties and correlating them with transport / thermodynamic parameters) of the electrolyte sample by use of THz spectroscopy.

[0052] The at least one access window is transparent to electromagnetic radiation. The parameters of the electrolyte sample are monitored based on characteristics of the electromagnetic radiation emanating from the at least one access window. Optionally, the electromagnetic radiation is of Terahertz frequency.

[0053] The access window is THz compatible, i.e., constituents of one or more components of the access window facilitate electromagnetic radiation of frequency in THz range (such as 0.1-10 THz) to propagate through the access window without getting attenuated. In some circumstances, the electromagnetic radiation is slightly attenuated as the electromagnetic radiation propagates through the access window. Furthermore, the one or more components of the access window are compatible with the chemistry of the electrolyte sample and are corrosion-proof. This ensures that performance of the battery / cell assembly does not deteriorate. The access window does not cause any mechanical stress to components of the battery / cell assembly. Furthermore, the one or more components of the access window may be sufficiently robust and stable, which prevents occurrences of safety hazards that lead to events such as short circuits, disconnections, or thermal runaway in a dynamic operating environment when the battery / cell assembly is subjected to vibrational forces.

[0054] The electrolyte sample absorbs the electromagnetic radiation incident on the at least one access window. The absorbed electromagnetic radiation gets scattered inside the electrolyte sample and propagates / penetrates to a certain depth inside the electrolyte sample where energy / amplitude of the electromagnetic radiation drops to a certain fraction (such as e-1) of an energy / amplitude of the electromagnetic radiation incident on the access window. The scattered electromagnetic radiation may reemerge from the access window. Based on absorption characteristics of the electromagnetic radiation emanating (i.e., reemerging) from the access window, the transport and thermodynamic parameters may be determined. The determinations of the transport and thermodynamic parameters over a period may be monitored for predicting state of health of the battery / cell assembly and whether the battery / cell assembly is likely to introduce a safety hazard.

[0055] In accordance with an embodiment, the battery management system may be associated with a user interface. The user interface may render measured values of the transport and thermodynamic parameters of the electrolyte sample. The user interface may further render state of health, capacity, lifetime of the battery / cell assembly, whether condition of the battery / cell assembly is deteriorating, and one or more conditions (such as Li plating, dendrite formation, and so on) that are causing or indicating the deterioration of the battery / cell assembly. The user interface may further render predictions that are indicative of likelihood of failure of the battery / cell assembly and messages that indicate that the electrolyte sample and the battery / cell assembly is under stress. The rendering may be based on the determination and / or monitoring of the transport and thermodynamic parameters of the electrolyte sample.

[0056] The present disclosure also relates to the third aspect as described above. Various embodiments and variants disclosed above, with respect to the aforementioned first aspect and the aforementioned second aspect, may apply mutatis mutandis to the third aspect.

[0057] The method comprises irradiating a prism with a first electromagnetic radiation of frequency. For example, the frequency of the first electromagnetic radiation may be in the range 0.1-10 THz. The prism may be integrated with the edges of the at least one access window. The at least one access window includes or is in contact with the electrolyte sample whose transport parameters and thermodynamic parameters are to be monitored in a non-invasive and / or non-destructive manner. Optionally, the method further comprises calibrating refractive indices of one or more of: the prism, one or more components constituting the at least one access window, and the electrolyte sample for the monitoring. Optionally, the first electromagnetic radiation is of Terahertz frequency. The first electromagnetic radiation is a THz beam that is generated by use of a THz source (for example, a photoconductive antenna, a quantum cascade laser, or a THz time-domain spectrometer). The irradiated first electromagnetic radiation, upon hitting a surface of the prism, penetrates the prism after getting refracted at a critical refraction angle. The first electromagnetic radiation may propagate through the prism in an evanescent mode prior to interacting with the access window edges.

[0058] The access window is THz compatible, i.e., transparent to Terahertz frequency radiation. Optionally, the components of the access window comprise at least one of: silicon (Si), polytetrafluoroethylene (PTFE), or polymethyl pentene (PMP). The compatibility of the components of the access window allows the first electromagnetic radiation to penetrate (i.e. pass through) the at least one access window. The electrolyte sample is a strong absorbent of THz electromagnetic radiation and, as such, may penetrate the at least one access window through its edges. After penetration, the first electromagnetic radiation may get scattered. Based on absorption and scattering of the first electromagnetic radiation, the transport, and thermodynamic parameters (i.e., the set of parameters) of the electrolyte sample may be determined.

[0059] The scattered electromagnetic radiation may penetrate to a certain depth / distance inside the electrolyte sample and re-enter the prism as the second electromagnetic radiation. Optionally, the second electromagnetic radiation is of Terahertz frequency. The second electromagnetic radiation propagates through the prism in an evanescent mode prior to emanating from another surface of the prism as the second electromagnetic radiation. The emanation or reemergence of the second electromagnetic radiation may be based on refraction at a certain angle of refraction.

[0060] The transport and thermodynamic parameters of the electrolyte sample are determined based on the one or more characteristic features of the second electromagnetic radiation. The one or more characteristic features may include variations in amplitude and / or variations in phase of the second electromagnetic radiation with respect to variations in frequency (in THz) of the second electromagnetic radiation. The features may include peak amplitude levels and frequencies at which peaks are recorded. The spectral features may change based on one or more of absorption peaks (amplitude, frequency), refractive index changes, or calibration curves (standard solutions with known electrolyte concentrations). Based on measurement of the one or more one or more characteristic features, the transport and thermodynamic parameters of the electrolyte sample are monitored. Optionally, the set of parameters that are monitored may include at least one of conductivity, ionic diffusion coefficients, an ionic concentration, a molar thermodynamic factor, and transference number. In accordance with an embodiment, a complex permittivity and absorption characteristics associated with the electrolyte solution is determined based on the variations of the amplitude and / or phase of the second electromagnetic radiation with respect to frequency variations. The transport and thermodynamic parameters may be extracted from the complex permittivity and the absorption characteristics.

[0061] The transport and thermodynamic parameters may be determined for varying concentrations of the electrolyte sample in a solvent (in which the electrolyte sample is dissolved). The transport and thermodynamic parameters may be determined in varying temperatures. The determined transport and thermodynamic parameters are reliable and accurate, and their measurement does not require sophisticated equipment (i.e., a range of laboratory tools), availability of electrolyte in specific concentrations, or making prior assumptions. In an embodiment, the battery / cell assembly may be monitored based on the transport and thermodynamic parameters for alerting the battery management system about potential failure of the battery / cell assembly. Optionally, the method further comprises generating an alert that is indicative of a state of health of the battery / cell assembly and capabilities of the battery / cell assembly in terms of its performance. The generation of the alert is based on the one or more characteristic features (such as amplitude / phase variations) of the second electromagnetic radiation. The alert may indicate an expected lifetime of the battery / cell assembly, an extent of degradation of the battery / cell assembly, an extent of reduction of lifetime and capacity of the battery / cell assembly, causes of reduction in lifetime / capacity and degradation of the battery / cell assembly (such as lithium plating, dendrite formation, and so on), and scope of failure of the battery / cell assembly. The alert is generated based on the transport and thermodynamic parameters of the electrolyte sample, which is turn is extracted from the one or more characteristic features of the second electromagnetic radiation. A continuous monitoring of parameters (such as electrolyte concentration) may reveal detailed information regarding depletion and degradation of constituents of the battery / cell assembly.

[0062] In an embodiment, the transport parameters of the battery / cell assembly may be correlated to degradation and safety indicators. Optionally, the method further comprises correlating the set of parameters (i.e., the transport parameters and / or the thermodynamic parameters) to one or more features that may be indicative of degradation of the battery and hazardous nature of the battery (from a safety perspective). The alert may be generated based on the correlation. For example, a determined value of a particular transport parameter may be indicative of a certain type of degradation of the battery / cell assembly. The value of the transport parameter, the type of degradation, and a prediction indicative of whether the degradation may lead to safety hazard if not managed within a due course of time, may be indicated in a generated alert.

[0063] Optionally, the at least one access window is disposed on at least one opening of the metallic housing. Each battery / cell of the cell assembly may be encased on the first surface of the polymeric layer. The metallic housing and a portion of the at least one access window is disposed on a second surface of a polymeric layer. The second surface is opposite to the first surface. The polymeric layer functions as a dielectric barrier between the metallic housing and the layer of battery / cell. The polymeric layer functions as a dielectric barrier between the at least one access window and the battery / cell. The polymeric layer may be constituted of polyamide (PI), synthetic polymers composed of polyamide such nylon, polyethylene terephthalate (PET), or polypropylene (PP), and so on.

[0064] DETAILED DESCRIPTION OF THE DRAWINGS

[0065] Referring to FIG. 1, there is illustrated an exemplary side-view 100 of an apparatus for monitoring transport and thermodynamic parameters of an electrolyte sample, in accordance with an embodiment of the present disclosure. The apparatus comprises a housing 102 and an access window 104. In some embodiments (such as the embodiment shown in FIG. 1, which may be a cylindrical or prismatic cell), the apparatus 100 includes a polymeric layer 106. The apparatus further includes a crosssection of electrode layers 108 (i.e., anode-separator-cathode layers). The housing 102 comprises at least one opening 102A on which access window 104 is disposed. The access window 104 is transparent to electromagnetic radiation (such as electromagnetic radiation of THz frequency range). The access window 104 may allow the electromagnetic radiation of THz frequency range to penetrate through the access window 104 window without attenuating the electromagnetic radiation. The access window 104 may include edges that are sealed. The parameters of the electrolyte sample are determined or monitored based on characteristics (such as amplitude variations and phase variations with respect to frequency) of the electromagnetic radiation (of THz frequency) emanating from the access window 104. The access window 104 comprises the electrolyte sample whose parameters may be required to be monitored. The access window components 104 may be compatible to the chemistry of the electrolyte sample in the access window 104.

[0066] The polymeric layer 106 functions as an insulating layer. The housing 102 is disposed on the polymeric layer 106, and a portion 1O4A of the access window 104 is disposed on the polymeric layer 106. The crosssection of electrode layers 108 is encased on a first surface 108A of the polymeric layer 106. The housing 102 and the access window 104 are disposed on a second surface 108B of the polymeric layer 106. The second surface 108B is opposite to the first surface 108A. The polymeric layer 106 functions as a dielectric barrier between the housing 102 and the cross-section of electrode layers 108.

[0067] FIG. 1 is merely an example, which should not unduly limit the scope of the claims herein. A person skilled in the art will recognize many variations, alternatives, and modifications of embodiments of the present disclosure. For example, the housing 102 may have any number of openings.

[0068] Referring to FIG. 2, there is illustrated an exemplary top-view 200 of the apparatus for monitoring transport and thermodynamic parameters of the electrolyte sample, in accordance with an embodiment of the present disclosure. As shown in FIG. 2, the top-view 200 depicts the housing 102, the access window 104, and the polymeric layer 106.

[0069] FIG. 2 is merely an example, which should not unduly limit the scope of the claims herein. A person skilled in the art will recognize many variations, alternatives, and modifications of embodiments of the present disclosure.

[0070] Referring to FIG. 3, depicted are steps of a method for monitoring transport and thermodynamic parameters of the electrolyte sample, in accordance with an embodiment of the present disclosure. At step 302, a prism is irradiated with a first electromagnetic radiation of Terahertz frequency. The first electromagnetic radiation propagates through the prism and gets scattered at an edge of the access window 104. The edge of the access window 104 is integrated to the prism and is transparent to the first electromagnetic radiation. The access window 104 includes or is in contact with the electrolyte sample whose parameters are (to be) monitored. The first electromagnetic radiation gets scattered upon interacting with the electrolyte sample in the access window 104. At step 304, a second electromagnetic radiation of Terahertz frequency, which is emanating from the prism, is detected. The detection is based on re-entry of scattered electromagnetic radiation of Terahertz frequency into the prism from the access window 104 and, subsequent, emanation from the prism as the second electromagnetic radiation. At step 306, one or more characteristic features (such as amplitude and phase) of the second electromagnetic radiation is measured. At step 308, a set of parameters of the electrolyte sample is monitored based on the one or more characteristic features. The set of parameters are the transport and thermodynamic parameters of the electrolyte sample which may be determined based on the one or more characteristic features. The determined transport and thermodynamic parameters are monitored.

[0071] The aforementioned steps are only illustrative and other alternatives can also be provided where one or more steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the claims herein.

[0072] FIG. 4 illustrates an exemplary placement of the access window 104 on a top-surface of a pouch battery 400, in accordance with an embodiment of the present disclosure. The pouch battery 400 may include an anode layer 402 and a cathode layer 404. The anode layer 402 and the cathode layer 404 is separated by a separator layer. The anode layer 402, the separator layer, the cathode layer 404 and the separator layer may be rolled by a metallic layer. The edges of each access window 104 are sealed. The access window 104 constitutes of one or more components that are THz compatible. The placement of the access window 104 is such that the access window 104 does not obstruct normal operation of the pouch battery 400 or the environment in which the access window 104 is embedded. The positioning of the access window 104 allows monitoring parameters of the electrolyte by probing a cross-section of anode-separator-cathode layers and an electrolyte sample.

[0073] In the present disclosure, the Terahertz electromagnetic radiation refers to electromagnetic waves having frequency in a range of 1012Hertz (Hz). The Terahertz (THz) electromagnetic radiation may be a frequency in a range of 0.1 Terahertz (THz) to 30 Terahertz (THz). Optionally, the electromagnetic radiation applied in the system, method or apparatus of the present invention is not limited to 0.1 THz to 30 THz and therefore may include any electromagnetic radiation. Depending on the source of electromagnetic radiation selected, the radiation may lie in the electromagnetic spectrum between radio waves and infrared waves. Optionally, the radiation may have wavelengths in range of 0.1 millimeters (mm) to 1 mm.

[0074] Optionally, the Terahertz electromagnetic radiation is non-ionizing in nature and propagates in a line-of-sight (LOS) or non-line of sight (NLOS). Typically, the Terahertz electromagnetic radiation can penetrate through non-conductive material. Subsequently, the Terahertz electromagnetic radiation may demonstrate limited penetration through the electrolyte passes therethrough. Additionally, the Terahertz electromagnetic radiation may depict a substantial decrease in power thereto owing to inability thereof in penetrating materials such as the metal of a battery electrode and / or dendrites on the surface of such electrode. Such decrease in power may be measured according to embodiments of the present invention.

Claims

CLAIMS1. An apparatus for monitoring parameters associated with an electrolyte sample of a battery, the apparatus comprising: a housing (102) with at least one opening; and at least one access window (104), wherein the at least one access window is disposed on the battery via at least one opening of the housing, wherein the at least one access window includes, or is in contact with, an electrolyte sample whose parameters are monitored, wherein the at least one access window is transparent to electromagnetic radiation, and wherein characteristics of the electromagnetic radiation is selected according to the parameters to be monitored, wherein the parameters to be monitored include at least one: of a conductivity, ionic diffusion coefficients, an ionic concentration, a molar thermodynamic factor, and a transference number.

2. The apparatus according to claim 1, wherein the apparatus further comprises a polymeric layer (106) functioning as an insulator, wherein the housing (102) is a metallic housing, wherein the polymeric layer insulates the battery from the metallic housing and the at least one access window, wherein the metallic housing is disposed on the polymeric layer, wherein a portion of the at least one access window is disposed on the polymeric layer, wherein the polymeric layer is constituted of one or more of: polyimide, nylon, polyethylene terephthalate, or polypropylene.

3. The apparatus according to claim 1, wherein the housing (102) is constituted of one of: aluminum, an aluminum alloy, a steel alloy, or an aluminum layer on a polymer.

4. The apparatus according to claim 1, wherein one or more components of the at least one access window (104) is chemically compatible to the electrolyte sample, wherein the electrolyte sample is one or more oflithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium Bis(fluorosulfonyl)imide, lithium oxide, lithium sulfide, polyethylene oxide, polyvinylidene fluoride, Magnesium bis(trifluoromethylsulfonyl)imide, zinc bromine, lithium phosphate, lithium phosphorous oxynitride, polyvinylidene fluoride-co- hexafluoropropylene, lithium borosilicate glass, sodium sulfide, polyacrylamide, lithium nitride, 0-alumina, sodium superionic conductor, lithium superionic conductor, polyvinyl alcohol, lithium phosphorous sulfide, lithium lanthanum zirconium oxide, lithium sulfide-phosphorus pentasulfide, lithium phosphorus sulfide, lithium aluminum titanium phosphate, lithium lanthanum titanium oxide, lithium germanium phosphorus sulfide, argyrodite, thio-lithium super ionic conductor, lithium phosphorus sulfide, zinc-bromine all-iron, zinc-air, zinc-vanadium, zinccerium, iron-chromium, all-vanadium, all-lead, vanadium-bromine, or sodium-bromine.

5. The apparatus according to claim 1, wherein the one or more components of the at least one access window (104) comprises at least one of: polymethyl pentene, polytetrafluoroethylene, or silicon.

6. The apparatus according to claim 1, wherein the battery is encased on a first surface of the polymeric layer (106), wherein the housing (102) and the at least one access window (104) are disposed on a second surface of the polymeric layer, wherein the second surface is opposite to the first surface, wherein the polymeric layer further functions as a dielectric barrier between the housing and the battery, and wherein the polymeric layer further functions as a dielectric barrier between the at least one access window and the battery.

7. The apparatus according to claim 1, wherein the electromagnetic radiation is of Terahertz frequency.

8. The apparatus according to claim 1, wherein the battery is a flowbattery.

9. The apparatus according to claim 1, wherein the flow battery is selected from the group consisting of: a Vanadium Redox Flow Battery (VRFB), an Iron-Chromium flow battery, a Zinc-Bromine flow battery, a Zinc-Iodine flow battery, and other redox flow battery systems.

10. A battery management system for monitoring parameters associated with an electrolyte sample, the battery management system comprising: a battery comprising a set of electrodes and an electrolyte sample; and at least one access window (104), wherein the at least one access window is disposed on the battery via at least one opening of a housing (102), wherein the at least one access window includes or is in contact with the electrolyte sample whose parameters are to be monitored, wherein the at least one access window is transparent to electromagnetic radiation, and wherein the parameters are monitored based on characteristics of the electromagnetic radiation emanating from the at least one access window.

11. The battery management system according to claim 10, wherein the electromagnetic radiation is of Terahertz frequency.

12. A method for monitoring parameters associated with an electrolyte sample of a battery, the method comprising: irradiating a prism with a first electromagnetic radiation, wherein the first electromagnetic radiation propagates through the prism and gets scattered at an edge of at least one access window (104), wherein the edge of the at least one access window is integrated to the prism and is transparent to the first electromagnetic radiation, wherein the at least one access window includes or is in contact with the electrolyte sample whose parameters are monitored, and wherein the first electromagneticradiation gets scattered upon interacting with the electrolyte sample in the at least one access window; detecting a second electromagnetic radiation emanating from the prism, wherein scattered electromagnetic radiation re-enters the prism and emanates from the prism as the second electromagnetic radiation; measuring one or more characteristic features of the second electromagnetic radiation; and monitoring a set of parameters of the electrolyte sample based on the one or more characteristic features, wherein the set of parameters that are monitored include at least one of a conductivity, ionic diffusion coefficients, an ionic concentration, a molar thermodynamic factor, and a transference number.

13. The method according to claim 12, wherein the method further comprises calibrating refractive indices of one or more of the prism, one or more components of the at least one access window (104), and the electrolyte sample.

14. The method according to claim 12, wherein the method further comprises generating an alert indicative of a state of health of the battery and performance capabilities of the battery, wherein the generation of the alert is based on the one or more characteristic features.

15. The method according to claim 12, wherein the method further comprises correlating the set of parameters to one or more features that are indicative of degradation of the battery and hazardous nature of the battery, wherein the alert is generated based on the correlation.

16. The method according to claim 12, wherein the at least one access window (104) is disposed on at least one opening of a metallic housing (102), wherein the battery is encased on a first surface of the polymeric layer, wherein the metallic housing and a portion of the at least oneaccess window is disposed on a second surface of a polymeric layer (106), wherein the second surface is opposite to the first surface, wherein the polymeric layer functions as a dielectric barrier between the metallic housing and the battery, wherein the polymeric layer functions as a dielectric barrier between the at least one access window and the battery, and wherein the polymeric layer is constituted of at least one of polyimide, nylon, polyethylene terephthalate, or polypropylene.

17. The method according to claim 12, wherein components of the at least one access window (108) comprises at least one of polytetrafluoroethylene, silicon, or polymethyl pentene.

18. The method according to claim 12, wherein each of the first electromagnetic radiation and the second electromagnetic radiation is of Terahertz frequency.

19. The method according to claim 12, wherein the battery is a flow battery.

20. The method according to claim 19, wherein the flow battery is selected from the group consisting of: a Vanadium Redox Flow Battery (VRFB), an Iron-Chromium flow battery, a Zinc-Bromine flow battery, a Zinc-Iodine flow battery, and other redox flow battery systems.

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