Method and apparatus for transferring vanadium-based batteries to standard conditions - Patent Application 20070122997

Abstract

At least some embodiments of the present disclosure relate to a semiconductor chip assembly including: a memory containing information regarding transition of a vanadium-based battery to a standard state; and a processor operatively connected to the memory and configured to provide instructions or commands regarding transition of the vanadium-based battery to a standard state by setting a constant temperature to be used in performing an open circuit voltage (OCV) measurement, setting one or more voltage values ​​for a specific voltage range to be used in performing the OCV measurement, and maintaining a balanced state of the vanadium-based battery while performing the OCV measurement. Also disclosed is a system including at least one energy storage component having a plurality of vanadium-based batteries arranged in a cell or pack; and a battery management component operatively connected to the energy storage component and providing battery management control for transitioning the energy storage component to a standard state.

Description

[Technical Field]

[0001] The disclosed technology relates to battery technology, and more particularly to a method and apparatus for transitioning vanadium-based batteries to standard conditions. [Background technology]

[0002] The growing global economy, coupled with global warming, continues to increase the urgency of the need for renewable and sustainable energy systems based on renewable energy sources such as solar and wind energy. To improve grid network stability against fluctuations due to the intermittent availability of these energy forms, advances in energy storage system (ESS) technology are used to store excess electricity, which can then be delivered to end customers or the grid when needed. It should be noted that ESS is also referred to as electrical energy storage systems (ESS). In particular, electrochemical-based ESS, such as rechargeable or secondary batteries, can provide cost-effective and clean energy storage solutions. Examples of electrochemical energy storage systems include lithium-ion, lead-acid, sodium-sulfur, and redox flow batteries. Different applications require different storage times: short-term, medium-term, and long-term storage. Different types of electrochemical energy storage systems have different physical and / or chemical properties. Competing factors considered in selecting and designing an appropriate electrochemical energy storage system for a particular application include investment costs, power, energy, lifetime, recyclability, efficiency, scalability, and maintenance costs.

[0003] Among various electrochemical energy storage systems, so-called redox batteries (RBs) are considered promising for stationary energy storage. RBs are electrochemical energy conversion devices that utilize the redox process of redox species dissolved in solution. Advantageous features of RBs include relative safety, independent scalability of power and energy, high depth of discharge (DoD), and reduced environmental impact. These features enable a wide range of operating power and discharge times, making RBs desirable for storing electricity generated from renewable sources. Summary of the Invention [Problem to be solved by the invention]

[0004] In order to improve upon existing electrochemical energy storage systems, the inventors of the present disclosure have conducted research and development to find improvements and solutions, particularly regarding certain risk factors such as fire hazards, explosion occurrences, etc. that continue to be faced when implementing lithium-ion batteries into energy storage systems (ESS).

[0005] Based on the recognition of the above-identified problems and in order to solve such problems, the inventors of the present disclosure have considered certain technical solutions to make vanadium-based batteries suitable for implementation in energy storage systems (ESS).

[0006] Accordingly, one of the many aspects of the present disclosure is to provide methods and apparatus for performing various evaluations for vanadium-based batteries used in energy storage systems (ESS) and other implementations.

[0007] Yet another of the many aspects of the present disclosure is to provide a method and apparatus for making the measurements necessary to transition a vanadium-based battery to a standard condition that is appropriate for and thereby evaluates the unique electrochemical and technical characteristics of the vanadium-based battery. [Means for solving the problem]

[0008] To solve the above problems, the present disclosure provides a semiconductor chip assembly, comprising: a memory containing information regarding transition of a vanadium-based battery to a standard state; and a processor operatively connected to the memory and configured to provide instructions or commands for transitioning the vanadium-based battery to a standard state, the standard state being transitioned to by setting a constant temperature to be used in performing an open circuit voltage (OCV) measurement and setting one or more voltage values ​​for a specific voltage range to be used in performing the OCV measurement, the processor further configured to provide instructions or commands for maintaining a balanced state of the vanadium-based battery while performing the OCV measurement.

[0009] According to at least one embodiment of the present disclosure, a method for semiconductor assembly is provided, the method including: bringing a vanadium-based battery to a standard state by setting a constant temperature to be used in performing open circuit voltage (OCV) measurements and setting a plurality of voltage values ​​for a specific voltage range to be used in performing the OCV measurements; and maintaining an equilibrium state of the vanadium-based battery while performing the OCV measurements.

[0010] In accordance with at least one embodiment of the present disclosure, a system having a semiconductor chip assembly is provided, the system comprising: at least one energy storage component having a plurality of vanadium-based batteries arranged in a cell or pack; and a battery management component operatively connected to the energy storage component and configured to provide battery management control for transitioning the energy storage component to a standard state, the standard state being transitioned to by setting a constant temperature to be used in performing OCV measurements on the vanadium-based batteries arranged in the cell or pack and setting a plurality of voltage values ​​for specific voltage ranges to be used in performing OCV measurements on the vanadium-based batteries arranged in the cell or pack, the battery management component further configured to provide battery management control for maintaining a balanced state of the energy storage component, or at least one vanadium-based battery therein, while performing the OCV measurements. [Effects of the Invention]

[0011] By establishing and employing standard conditions for vanadium-based batteries in accordance with embodiments of the present disclosure, more accurate measurements and estimates can be made for vanadium-based batteries compared to situations in which such standard conditions are not established and employed.

[0012] Additionally, employing standard conditions for vanadium-based batteries in accordance with embodiments of the present disclosure allows for more efficient charging and / or discharging of the vanadium-based batteries, thereby enabling more precise battery management, power control, and energy storage system operation.

[0013] In particular, embodiments of the present disclosure enable vanadium-based batteries to be successfully adapted and implemented into energy storage systems (ESS). [Brief explanation of the drawings]

[0014] [Figure 1]FIG. 1 illustrates an exemplary redox battery cell that can be implemented as part of a vanadium-based battery and / or energy storage system applicable to at least some embodiments described herein. [Figure 2] FIG. 2 shows a perspective view of an exemplary structure of a vanadium-based battery applicable to at least some embodiments described herein. [Figure 3] FIG. 3 shows a cross-sectional view taken along dashed line AA in FIG. [Figure 4] FIG. 4 illustrates an exemplary battery module having a plurality of vanadium-based battery cells applicable to at least some embodiments described herein. [Figure 5] FIG. 5 illustrates some characteristics of constant current (CC) and / or constant voltage (CV) control methods applied to battery charging that are applicable to at least some embodiments described herein. [Figure 6] FIG. 6 shows the voltage versus current relationship during charging and discharging at the two electrodes of a VFRB applicable to at least some embodiments described herein. [Figure 7] FIG. 7 shows several graphs of different data sets with data relating to charging and discharging a battery at a constant current. [Figure 8] FIG. 8 illustrates some basic electrochemical characteristics of a vanadium-based battery according to at least some embodiments described herein. [Figure 9] FIG. 9 illustrates two scenarios of battery cell resistance versus IR drop at or near the inflection point during charging or discharging according to at least some embodiments described herein. [Figure 10] FIG. 10 shows an exemplary graph of experimental results depicting the determination of terminal discharge voltage at high current density using pulse galvanostatic measurement curves and internal resistance curves applicable to at least some embodiments described herein. [Figure 11] FIG. 11 depicts the SoC vs. OCV relationships for short charge, long charge / discharge, and short discharge. [Figure 12] FIG. 12 depicts the effect of environmental temperature on vanadium-based battery performance. [Figure 13] FIG. 13 shows an example flow chart of a standard state transition procedure for a vanadium-based battery according to at least some embodiments described herein. [Figure 14] FIG. 14 illustrates an example apparatus capable of performing the steps of FIG. 13 in accordance with at least some embodiments described herein. [Figure 15] FIG. 15 illustrates a semiconductor chip assembly according to at least some embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0015] The following embodiments can be modified in various ways, and the scope of the present disclosure is not limited to the following embodiments. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. In the following description, it should be noted that detailed descriptions of the functions of conventional elements and elements related to the present disclosure will be omitted if such detailed descriptions may obscure the gist of the present disclosure.

[0016] Furthermore, the following drawings are provided as examples to fully convey the concept of the present disclosure to those skilled in the art to which the present disclosure pertains. Therefore, the present disclosure is not limited to the accompanying drawings provided below, but may be modified in many different forms. Furthermore, the accompanying drawings suggested below may be exaggerated to clarify the spirit and scope of the present disclosure. Furthermore, like reference numerals refer to elements throughout the specification.

[0017] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0018] Additionally, in describing components of the present disclosure, terms such as first, second, A, B, (a) or (b) may be used. These terms are provided merely to distinguish components from one another and do not limit the nature, order, or arrangement of the components. When an element is referred to as being "coupled" or "connected" to another element, it will be understood that this may be directly coupled or connected, or that there may be intervening elements.

[0019] In this disclosure, the term "battery cell" refers to the smallest unit in which charging and discharging occurs through an electrolyte, and includes a membrane where ion exchange occurs, a separator, and the like. In this disclosure, the term "stack" means a stack or arrangement of multiple battery cells.

[0020] Vanadium-based batteries, such as vanadium redox batteries (VRBs), vanadium redox / flow batteries (VRFBs or VFRBs), vanadium flow batteries (VFBs), and vanadium-ion batteries (VIBs), are considered more promising for ESS / EES implementations and other applications related to the battery industry. These vanadium-based batteries share at least some of the advantages characteristic of RFBs. However, unlike conventional non-vanadium-based RFBs, vanadium-based batteries are significantly less flammable and less susceptible to damage due to the properties of the vanadium used in them.

[0021] 1 , a notable structural feature of redox batteries according to some embodiments herein, compared to some conventional redox batteries, such as redox flow batteries (RFBs), is the omission of a pump. Instead, redox battery 200A according to some embodiments is configured such that first and second electrolytes self-circulate within positive electrolyte reservoir 106A of first half-cell 204A and negative electrolyte reservoir 106B of second half-cell 204B, respectively. In various configurations, the self-circulation of the first and second electrolytes is caused by one or more of the following: an osmotic pressure difference between the first and second electrolyte reservoirs; density changes in one or both of the first and second electrolytes; diffusion or migration of one or both of the first and second electrolytes; affinity of one or both of the first and second electrolytes for the first and second electrodes, respectively; first and second redox half-reactions; and thermal expansion or contraction of one or both of the first and second electrolytes. The inventors have discovered that self-circulation is effective in providing stability in power and energy output when the thickness at cross section of the positive and negative electrolyte reservoirs 106A, 106B does not exceed 20 cm, 15 cm, 10 cm, 5 cm, 2 cm, 1 cm, or a value within a range defined by any of these values.

[0022] A redox battery configured in this manner offers various technical and commercial advantages. For example, various reliability failures associated with conduits (e.g., piping joints) between the battery cells and the tank and pumps for circulating the electrolyte are substantially reduced or eliminated, thereby reducing unscheduled repairs, safety hazards, and operational costs associated with operating the redox battery 200A. Furthermore, by eliminating the need for a pump to circulate the electrolyte between the battery cells and the tank, external efficiency is significantly improved. The inventors have recognized that, depending on the size of the system, the redox battery 200A can achieve up to a 2-50x increase in power or energy density compared to a conventional RFB by eliminating the need to circulate the electrolyte between the cells and the electrolyte tank. As discussed above, power or energy density refers to the power or energy output, respectively, of a storage device relative to the total volume of the energy storage device. Therefore, in the case of a redox battery, power or energy density refers to the ratio of power or energy output, respectively, to the total volume of the redox battery. Furthermore, by eliminating a circulation system including separate tanks, pumps, and conduits, space efficiency is significantly improved. Furthermore, the system complexity is significantly reduced, which significantly lowers the barriers to commercial implementation of redox batteries. For example, unlike conventional RFBs, redox battery 200A can be manufactured in packs similar to lithium-ion batteries, and due to its modular implementation, it does not require the invasive construction that may be required to install conventional RFBs, making it more amenable to automation and mass production.

[0023] The following describes the operating principles and aspects of redox batteries using the example of a vanadium (V) redox battery based on a vanadium-based redox couple, but it will be understood that embodiments are not so limited and that the principles described herein can also be applied to redox batteries according to a variety of other redox couples.

[0024] Reference is made below to Figures 2 to 6. An exemplary structure of a vanadium-based battery (e.g., a vanadium-ion battery: VIB) applicable to at least some embodiments described herein comprises a so-called first liquid electrode where a first electrochemical reaction takes place, a so-called second liquid electrode where a second electrochemical reaction takes place, a frame 110 having a first electrode receptacle / reservoir 111a that houses the first liquid electrode and a second electrode receptacle / reservoir 111b that houses the second liquid electrode, and a separation / ion exchange membrane 120 between the first electrode receptacle 111a and the second electrode receptacle 111b. Also present is a first current collector 130a in contact with the first electrode receptacle 111a and electrically connecting with the first liquid electrode, and a second current collector 130b in contact with the second electrode receptacle 111b and electrically connecting with the second liquid electrode. Additionally, there may be a first solid electrode (bipolar plate) 150a in a first electrode receptacle 111a immersed in a first liquid electrode, and a second solid electrode (bipolar plate) 150b in a second electrode receptacle 111b immersed in a second liquid electrode. Additionally, there is a first insulator 170a between the frame 110 and the first current collector 130a, and a second insulator 170b between the frame 110 and the second current collector 130b.

[0025] So-called liquid electrodes contain specific ions that undergo redox (i.e., reduction and oxidation) reactions. Therefore, the first liquid electrode can be an electrolyte with a dissolution of an anode redox couple. The anode redox couple can be implemented as elements or components including transition metals such as titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), or zinc (Zn), bromine (Br), and cesium (Cs). In some embodiments herein, vanadium (V) is employed to represent V. 2+ / V 3+The first liquid electrode is an acidic aqueous solution, such as sulfuric acid (H2SO4), in which ionization can induce or enable the transmission of electric current. In some embodiments, the first liquid electrode can be fabricated by dissolving VOSO4 (vanadyl sulfate), VO5 (vanadium pentoxide), or other suitable material in a H2SO4 (sulfuric acid) solution.

[0026] The first liquid electrode undergoes the so-called first half-cell reaction shown below, where the right-pointing arrow (->) indicates the discharge direction and the left-pointing arrow (<-) indicates the charge direction: 2+ <- ->V 3+ +e - That is, during discharge, vanadium ions in the +2 oxidation state (i.e., V 2+ ions) are oxidized to vanadium ions in oxidation state +3 (i.e., V 3+ ions), and during charging, vanadium ions in oxidation state +3 (i.e., V 3+ ions) are reduced to vanadium ions in oxidation state +2 (i.e., V 2+ ions).

[0027] The frame 110, first current collector 130a and separator 120 are configured to surround a first liquid electrode housed in a first electrode receptacle 111a and prevent (or minimize) leakage of the first liquid electrode, and the first solid electrode 150a may be immersed in the first liquid electrode.

[0028] The first liquid electrode is electrically connected to the first current collector 130a, so that electrons move to the first current collector 130a during discharge and move away from the first current collector 130a during charge. In addition, the first liquid electrode is in contact with the separation membrane 120, so that hydrogen cations (i.e., positive ions or protons) can pass through or move through the separation membrane 120.

[0029] Similarly, the second liquid electrode can also be an electrolyte having an anodic redox couple dissolved therein. The anodic redox couple can be implemented as elements or components including transition metals such as titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), or zinc (Zn), bromine (Br), and cesium (Cs), although some embodiments herein employ vanadium (V) to form the V 4+ / V 5+ The second liquid electrode forms a redox couple. This second liquid electrode is an acidic aqueous solution, such as sulfuric acid (H2SO4), in which ionization can induce or enable the transmission of electric current. In some embodiments, the second liquid electrode can be fabricated by dissolving VOSO4 (vanadyl sulfate), VO5 (vanadium pentoxide), or other suitable material in a H2SO4 (sulfuric acid) solution.

[0030] The second liquid electrode undergoes the so-called second half-cell reaction shown below, where the right-pointing arrow (->) indicates the discharge direction and the left-pointing arrow (<-) indicates the charge direction: 5+ +e - <- -> V 4+ That is, during discharge, vanadium ions in the +5 oxidation state (i.e., V 5+ ions) are oxidized to vanadium ions in oxidation state +4 (i.e., V 4+ ions), and during charging, vanadium ions in the +4 oxidation state (i.e., V 4+ ion) is reduced to a vanadium ion in oxidation state +5 (i.e., V 5+ ions).

[0031] The frame 110, second current collector 130b and separator 120 are configured to surround a second liquid electrode housed in a second electrode receptacle 111b and prevent (or minimize) leakage of the second liquid electrode, and the second solid electrode 150b may be immersed in the second liquid electrode.

[0032] The second liquid electrode is electrically connected to the second current collector 130b, so that electrons move to the second current collector 130b during discharge and move away from the second current collector 130b during charge. In addition, the second liquid electrode is in contact with the separation membrane 120, so that hydrogen cations (i.e., positive ions or protons) can pass through or move through the separation membrane 120.

[0033] As can be seen from the above, the first and second liquid electrodes are of the same material or composition and contain vanadium ions in the same electrolyte. Hereinafter, the first and second liquid electrodes will be referred to simply as liquid electrodes.

[0034] The frame 110 may have a rectangular loop shape as shown in the drawings. In some embodiments, different shapes may be employed, such as a diamond shape, a circle, a pentagon, or other polygonal shape. The frame 110 may also have a particular thickness. At least a portion of the frame 110 may form at least a portion of the first and second electrode receptacles 111 a, 111 b. The particular shape and / or thickness of the frame 110 depends on how the vanadium-based battery is implemented and the structural requirements therefor, taking into account trade-offs between overall size, weight, battery capacity, charge / discharge operation, manufacturing costs, etc.

[0035] The space within or created by the frame 110 is divided into a first electrode receptacle 111a and a second electrode receptacle 111b by a separator membrane 120 therebetween, which may be attached to and / or supported by the frame 110.

[0036] A first current collector 130a is located on one side, end, or edge of the frame 110, and a second current collector 130b is located opposite the other side, end, or edge of the frame 110. Furthermore, the space of the frame 110 is closed by the first current collector 130a and the second current collector 130b, so that the entire periphery of the frame 110 is configured to prevent leakage of the first and second liquid electrodes. Therefore, the frame 110 forms a first electrode receptacle 111a between the first current collector 130a and the separator membrane 120, and a second electrode receptacle 111b between the second current collector 130b and the separator membrane 120.

[0037] The first and second liquid electrodes are housed within the frame 110, and the first and second solid electrodes 150a, 150b are said to be disposed therein. Also, first and second gaskets 160a, 160b may be provided along first and second peripheries or edges, respectively, of the frame 110. Furthermore, a first insulating member 170a is on one side of the frame 110, and a second insulating member 170b is on the opposite side.

[0038] The first electrode receptacle 111a and the second electrode receptacle 111b are in fluid communication via a transition element 112 that is part of the frame 110. Such transition element 112 is part of the frame 110 and has holes or openings at each end in the form of grooves or channels along its edges. The liquid electrode can enter such holes or openings and flow through the grooves or channels in the frame 110.

[0039] Separator membrane 120 is located within frame 110 and separates the first and second liquid electrodes, allowing hydrogen cations (i.e., positive ions or protons) to move or pass between them. Separator membrane 120 is located between first and second current collectors 130a, 130b and is attached to the edge of frame 110. During discharge, hydrogen cations move from the first liquid electrode to the second liquid electrode, and during charge, they move from the second liquid electrode to the first liquid electrode.

[0040] The separation membrane 120 may include at least one of a perfluorinated ionomer, a partially fluorinated polymer, and a non-fluorinated hydrocarbon, and may be made from at least one of Nafion®, Flemion®, NEOSEPTA-F®, and Gore Select®, or other commercially available materials.

[0041] Although the separator membrane 120 essentially prevents the first and second liquid electrodes from mixing with each other, a crossover effect caused by small amounts of vanadium ions and water passing through can occur. Such a crossover effect can cause an imbalance in the respective amounts of the first and second liquid electrodes, potentially affecting the performance and lifespan of the vanadium-based battery. While some conventional redox secondary battery systems with tanks and pumps can resolve such undesirable differences in the amounts of liquid electrode material, the embodiments described herein do not employ such tanks and pumps. Instead, the embodiments described herein are specifically configured to allow a small amount of liquid electrode to flow between the first and second electrode receptacles 111a, 111b to resolve the imbalance due to crossover and maintain a relative balance between them.

[0042] First current collector 130a is provided along one side of frame 110 and, together with separator 120, forms first electrode receptacle 111a. Correspondingly, second current collector 130b serves as a counterpart to first current collector 130a. First current collector 130a is in intimate contact with first gasket 160a of frame 110 and in contact with first insulating member 170a, but is not in direct contact with the first and second liquid electrodes, which may flow in small amounts through transition element 112. First current collector 130a is also in electrical contact with the first liquid electrode, allowing electrons to transfer and current to flow during charging and discharging.

[0043] As shown in FIG. 4, when multiple batteries or battery cells form a module and multiple frames 110 and multiple first and second current collectors 130a, 130b are stacked, at least one of the first and second current collectors 130a, 130b can be electrically connected via a bus bar (not shown) or other connector to realize parallel connection of the batteries or battery cells.

[0044] The first current collector 130a is made of metal and includes a first metal current collector 131a electrically connected to the bus bar, and a first carbon current collector 132a located between the frame 110 and the first metal current collector 131a.

[0045] The first carbon current collector 132a can be made of graphite, carbon, carbon plastic, or other materials with high electrical conductivity and high acid resistance. The first carbon current collector 132a is located between the first liquid electrode and the first metal current collector 131a, allowing electrons to transfer between them without causing oxidation of the first metal current collector 131a. The first carbon current collector 132a may be in the shape of a rectangular plate or may be applied to the first metal current collector 131a.

[0046] The first metal current collector 131a is made of a highly conductive material such as copper or aluminum, and may have a rectangular plate shape with a protruding portion to allow connection with a bus bar or connector.

[0047] The first metal current collector 131a can be made of a flexible film or a rigid plate. When multiple batteries or battery cells form a module, as shown in Figure 4, most of the first metal current collector 131a can be a flexible film, and some can be a rigid plate that may provide better connection with bus bars or connectors.

[0048] The first carbon current collector 132a is located on one side of the first metal current collector 131a. When multiple batteries or battery cells form a module, as shown in Figure 5, the first carbon current collector 132a is located on both sides of the first metal current collector 131a.

[0049] The second current collector 130b is located on the opposite side of the frame 110 and, together with the separator 120 and the frame 110, forms a second electrode receptacle 111b. The second current collector 130b is parallel to and spaced apart from the first current collector 130a. The second current collector 130b is in intimate contact with the second gasket 160b of the frame 110 and in contact with the second insulating member 170b, but is not in direct contact with the first and second liquid electrodes, which may flow in small amounts through the transition element 112. Additionally, the second current collector 130b is in electrical contact with the first liquid electrode, allowing electrons to transfer and current to flow during charging and discharging.

[0050] As shown in FIG. 4, when multiple batteries or battery cells form a module and multiple frames 110 and multiple first and second current collectors 130a, 130b are stacked, at least one of the first and second current collectors 130a, 130b can be electrically connected via a bus bar (not shown) or other connector to realize parallel connection of the batteries or battery cells.

[0051] The second current collector 130b is made of metal and includes a second metal current collector 131b electrically connected to the bus bar, and a second carbon current collector 132b located between the frame 110 and the second metal current collector 131b.

[0052] The second carbon current collector 132b can be made of graphite, carbon, carbon plastic, or other materials with high electrical conductivity and high acid resistance. The second carbon current collector 132b is located between the second liquid electrode and the second metal current collector 131b, allowing electrons to transfer between them without causing oxidation of the second metal current collector 131b. The second carbon current collector 132b may be in the shape of a rectangular plate or may be applied to the second metal current collector 131b.

[0053] The second metal current collector 131b is made of a highly conductive material such as copper or aluminum, and may have a rectangular plate shape with a protruding portion to allow connection with a bus bar or connector.

[0054] The second metal current collector 131b can be made of a flexible film or a rigid plate. When multiple batteries or battery cells form a module, as shown in Figure 4, most of the second metal current collector 131b can be a flexible film, and some can be a rigid plate that may provide better connection with bus bars or connectors.

[0055] The second carbon current collector 132b is located on one side of the second metal current collector 131b. When multiple batteries or battery cells form a module, as shown in Figure 5, the second carbon current collector 132b is located on both sides of the second metal current collector 131b.

[0056] According to some embodiments, the first gasket 160a provides a seal between the first current collector 130a and the frame 110, and the second gasket 160b provides a seal between the second current collector 130b and the frame 110.

[0057] The first and second gaskets 160a, 160b are made of a flexible material such as rubber or synthetic resin, and may be in the form of a rectangular loop or other shape that matches the shape of the frame 110. The first solid electrode 150a is located in the first electrode receptacle 111a and is impregnated with the first liquid electrode. The first solid electrode 150a is surrounded by the frame 110, the first current collector 130a, and the separator 120. The first solid electrode 150a may comprise a carbon-based material such as carbon or graphite felt, carbon cloth, carbon black, graphite powder, or graphene. The first solid electrode 150a may have a porous rectangular shape. The first solid electrode 150a may have a thickness greater than that of the first electrode receptacle 111a, in which case it may be housed therein in a tight contact manner. The first solid electrode 150a is in close contact with the first current collector 130a and the separator 120.

[0058] The second solid electrode 150b may comprise a carbon-based material such as carbon or graphite felt, carbon cloth, carbon black, graphite powder, or graphene. The second solid electrode 150b may have a porous rectangular shape. The second solid electrode 150b may have a thickness greater than that of the second electrode receptacle 111b, and in this case, may be housed therein in a manner of intimate contact. The second solid electrode 150b is in intimate contact with the second current collector 130b and the separator 120.

[0059] The overall configuration of the secondary battery having the above structure of the present disclosure can be explained as follows. The separator 120 is disposed at the center in the out-of-plane direction of a rectangular frame 110 having a specific thickness, a first current collector 130a is disposed on one side of the frame 110 in the out-of-plane direction, and a second current collector 130b is disposed on the other side of the frame 110 in the out-of-plane direction, thereby forming a first electrode receptacle 111a and a second electrode receptacle 111b. In other words, the frame 110 is disposed between the first current collector 130a and the second current collector 130b, and the separator 120 is disposed within the frame 110.

[0060] 4, the above structure is alternately repeated to form a module, i.e., first current collector 130a may be disposed between a plurality of frames 110 each having a separator 120 attached thereto, and second current collector 130b may be disposed between a plurality of frames 110 each having a separator 120 attached thereto.

[0061] A first solid electrode 150a impregnated with a first liquid electrode is disposed in the first electrode receptacle 111a, and a second solid electrode 150b impregnated with a second liquid electrode is disposed in the second electrode receptacle 111b. A first gasket 160a is disposed between the first current collector 130a and the frame, and a second gasket 160b is disposed between the second current collector 130b and the frame.

[0062] The first current collector 130a includes a first carbon current collector 132a and a first metal current collector 131a, and the second current collector 130b includes a second carbon current collector 132b and a second metal current collector 131b. On the side of the first electrode receptacle 111a, the first carbon current collector 132a and the first metal current collector 131a are stacked in sequence. On the side of the second electrode receptacle 111b, the second carbon current collector 132b and the second metal current collector 131b are stacked in sequence.

[0063] Below, we discuss some aspects related to the charging and discharging operations of secondary or redox (eg, vanadium-based) batteries. Establishing the exact charge / discharge voltage range of a battery is not an easy task. The voltage within a battery is affected by the composition of elements within the battery, the charge / discharge conditions, the charge / discharge control method, etc. In an environment with such many variables, there are only two reliable measurement types available in practice: voltage and current.

[0064] Typically, companies in the battery industry have attempted to establish appropriate charge / discharge voltage ranges for their products essentially using a trial-and-error approach. For most batteries, the two opposing endpoints in the state-of-charge (SoC) characteristic are where extreme changes in voltage (i.e., electromotive force: EMF) are observed. That is, when a fully charged or fully discharged state is reached, the slope of the charge / discharge curve changes significantly. Many battery manufacturers measure this slope and set "charge / discharge windows" appropriately for their products, commonly referred to in the industry as "rated voltage ranges."

[0065] However, since the traditional trial and error method may not be optimal due to variations therein, the inventors of the present disclosure have explored some basic principles to establish more suitable or accurate charge / discharge voltage ranges, based on the following:

[0066] Referring to Figure 5, when a battery is charged (or discharged), a constant current (CC) control method and / or a constant voltage (CV) control method is applied. Under CV control, the voltage is kept constant, so even if the state of charge (SoC) is high, it cannot exceed a certain voltage and the amount of current is reduced accordingly. In other words, this is a safe control method when the battery is near the fully charged region. In contrast, when CV control is applied in a low SoC state, the potential difference at the battery anode is low while the voltage is high, which increases the IR value and can result in a dangerously large increase in current.

[0067] Under CC control, the amount of current is kept constant, so the number of charges transferred per time unit is the same regardless of the SoC. This means that this is a safe way to control the battery in low SoC situations. In contrast, if there is a delay in the control response to sudden voltage changes as the SoC increases, the safe voltage range may be temporarily exceeded.

[0068] Thus, many types of batteries apply a combination of both CC and CV control to achieve battery charging (and / or discharging) in a safe manner. For vanadium-based batteries, charging and discharging are driven by reduction and oxidation (i.e., redox) reactions, and the potential difference between the anode and cathode greatly affects how energy is stored and released. The relevant redox reactions are shown below:

[0069]

number

[0070] A change in concentration (of the liquid electrodes) at the anode or cathode results in a difference in their potential, which manifests as the open circuit voltage (OCV) of the battery cell (I=O). The so-called "state of charge (SoC)" indicates how much the density of an electrolyte in oxidation state +3 and the density of an electrolyte in oxidation state +4 change from theoretical 100% to 0%, respectively.

[0071] Equilibrium cell potential for each reaction, E eq is calculated using the Nernst equation (which relates ion density to voltage) according to:

[0072]

number

[0073] The voltage measured externally from a battery cell is affected by the current applied during charging and / or discharging of the battery cell. Current multiplied by resistance gives a voltage (ie, V=IR), and such a voltage increase or decrease is commonly referred to as an ohmic loss.

[0074] However, the actual operating voltage of VRFB differs from this thermodynamic value. The charging voltage may be greater than 1.2V because an overvoltage is required in addition to the thermodynamic voltage. Referring to FIG. 6, the following equations show the relationship between voltage and current during charging and discharging at the two electrodes of a VFRB, assuming that the overall reaction rate is determined by charge transfer in the electrochemical reaction.

[0075]

number

[0076] As shown in the equations above, there are some anode / cathode overvoltages due to current, but unlike lithium-ion batteries (LIBs) and lead-acid batteries, such overvoltages are negligible (i.e., small enough to be ignored) in vanadium-ion batteries (VIBs) because there are no phase changes (e.g., liquid to solid or solid to liquid) for the ions in the VIBs.

[0077] In the graph of Figure 8, the areas showing abrupt changes indicate that the battery is damaged or its efficiency is decreasing, which corresponds to the area where charging is performed at a high SoC or discharging is performed at a low SoC. In other words, an important aspect of battery control is related to how the voltage conditions at the end of charging and the end of discharging should be set.

[0078] Below, methods for performing voltage range measurement tests according to at least some embodiments are described. Figure 7 shows some graphs of different data sets with data on charging and discharging a battery at a constant current. These graphs are not related to VIB and are provided simply for technical background.

[0079] For each of the three graphs, the corresponding slopes change significantly at certain points: at or near the beginning of charging, at or near the end of charging, at or near the beginning of discharging, and at or near the end of discharging. The linear region, shown as the dotted line, is traditionally used as the typical voltage range for battery control, taking into account various factors such as ease of control, safe operating conditions, and battery life cycle.

[0080] Now, many different factors may be used to determine how and where the endpoints of a typical voltage range should be set. For example, each endpoint can be determined as where the linearity of the data points tends to stop. Alternatively, the change in slope can be measured for multiple data points, and a specific threshold slope can be set or used to determine where the endpoints are. Alternatively, trial and error measurements may be found to result in a more effective setting of the endpoints. Alternatively, battery testing and operating experience may prove to be indicative of how the endpoints should be optimized. These fundamental questions and numerous considerations led the inventors of the present disclosure to devise the following technical approach.

[0081] It should be noted that although the inventors of this disclosure have focused on vanadium-based batteries (such as VIBs and VRFBs), some or all of the concepts and details provided in this disclosure may also be applicable to other types of batteries.

[0082] Based on certain fundamental electrochemical characteristics of vanadium-based batteries, the following test method is proposed to determine the appropriate voltage range for a VIB. FIG. 8 illustrates some basic electrochemical characteristics of a VIB according to at least some embodiments described herein, including (a) a pulse galvanostatic measurement curve, (b) an internal resistance curve, and (c) a galvanostatic charge / discharge curve.

[0083] Pulsed galvanostatic measurements were carried out to investigate the electrochemical process controlled by the kinetics of the vanadium ion reaction between the solid electrode and the liquid electrode. As shown in curve (a) of Figure 10, at 10 mAg -1 A pulse current of 0 V was repeatedly applied for 1 minute, followed by 5 minutes of open-circuit relaxation in the voltage range of 0 to 2 V. It was noted that during both pulse charge and discharge operations, the pulse voltage remained consistently low between approximately 1.2 V and approximately 1.6 V, indicating that polarization within the VIB remained low within the corresponding 1.2 V to 1.6 V range. However, once the potential exceeded the 1.2 V to 1.6 V range, the pulse voltage rapidly increased, indicating that the vanadium reactant in the liquid electrode was consumed and polarization increased. The 1.2 V to 1.6 V range is based on experiments conducted by the inventors of this disclosure; a different voltage range may be used depending on the circumstances. This voltage range may be adjusted as needed depending on the electrochemical characteristics of the redox battery and / or the battery application. For example, the starting voltage may be 1.0 V to 1.2 V, and the ending voltage may be slightly above 1.6 V.

[0084] To clearly observe the kinetic behavior, the internal resistance of the VIB was calculated from the pulse galvanostatic charge / discharge data by dividing the pulse voltage by the current, as can be seen from curve (b) in Figure 8. It was observed that the internal resistance remained constant at a nominal resistance of approximately 20 mΩ within the range of 1.2 V to 1.6 V, indicating that fresh vanadium reactants were instantly supplied to the carbon reaction sites. The carbon electrode repels the reaction products, allowing fresh reactants to approach, which is considered to be the driving force for the microfluidic movement within the VIB. When the potential exceeded the 1.2 V to 1.6 V range, the internal resistance rapidly increased as the vanadium reactants were consumed. Therefore, energy losses will occur if the VIB is operated outside the open-circuit voltage (OCV) range of 1.2 V to 1.6 V.

[0085] The basic procedure formulated by the present inventors for establishing a desired voltage range for battery control can be considered fairly simple. According to such a procedure, charging and / or discharging is performed using a constant current, but (i) a specific time period is set (or established) periodically or in some other manner to obtain a specific time domain, then (ii) the current for each time domain is initialized (i.e., set equal to zero), and (iii) the IR drop is measured for each. In other words, an appropriate voltage range (e.g., to be used for VIB control) can be established based on multiple equivalent internal resistance values ​​measured for multiple open-circuit voltage (OCV) values ​​corresponding to state-of-charge (SoC) values ​​or relevant domains.

[0086] It should be noted that the VIB contains a suitable electrolyte, which can be referred to as the anode (or positive electrode) and cathode (or negative electrode) liquid electrodes within the VIB. If there is a change in the amount or degree of electrical charge within such electrolyte, i.e., if the average oxidation state (or number) of the ions therein changes, the amount or degree of resistance change within the VIB must be measured relative to the OCV to achieve the desired battery control. In theory, the OCV and SoC can be matched to each other in a one-to-one ratio, so measuring the OCV can yield the desired VIB internal resistance value.

[0087] In the basic procedure, the length or interval of the time period or region can be set appropriately, as long as the frequency is not too fast. For example, an interval of approximately 10 to 20 Hz may be too narrow (or too fast) for proper measurements. That is, the time period, region, or interval should be set long enough to allow current initialization and IR drop measurements to be performed and the OCV check to be as accurate as possible. In the best mode of at least one embodiment, a minimum interval of approximately 0.1 seconds can be adopted to ensure that the desired current initialization and necessary measurements are properly performed.

[0088] A relatively narrow time interval can result in a higher density of data points on the resistance vs. OCV curve, potentially leading to relatively high accuracy. Higher accuracy requires more processing power and time. Therefore, a trade-off exists between these and other competing factors. For example, some procedures for current initialization may be burdensome, but if a highly accurate battery control voltage range is necessary and critical, the time period can be set as needed to perform measurements and calculations such as current initialization. In contrast, if overall system stability is given a higher priority, the number of times current initialization, etc., is performed to find the desired battery control voltage range can be minimized.

[0089] In basic procedures, measuring IR drop can be accomplished in a variety of ways. Here, IR drop can be measured for all time periods or only for specific time periods. For example, an inflection point in the resistance vs. OCV curve is of particular interest, so only the IR drop at or near such a point can be measured. In contrast, if more IR drop readings are required, they can be performed accordingly.

[0090] For example, referring to FIG. 9, the first data point (shown as a circular shape) represents a situation where the battery cell has a high resistance, and therefore a larger magnitude of IR drop at or near the inflection point during charging or discharging. In contrast, the second data point (shown as a rectangular shape) represents a battery with better performance characteristics, and therefore a smaller magnitude of IR drop. In this manner, the performance of the battery can be determined in a comparative manner.

[0091] There can be a trade-off between the number of IR-drop measurements you need to make, given the time and processing involved. For example, returning to Figure 9, which shows IR-drop measurements taken every minute during the test procedure, you might decide that IR-drop measurements near the beginning and end of the test procedure don't need to be taken every minute; taking measurements every 3 minutes might be sufficient. In contrast, at or near the inflection point, additional detailed measurements (every minute, every 30 seconds, every 5 seconds, etc.) might be more meaningful in determining the exact value at which IR-drop dramatically changes. The specific VIB or specific battery characteristics (e.g., battery capacity, overall size, type of commercial application, operating environment, daytime vs. nighttime charging or discharging, manufacturing costs, operating costs, etc.) can influence how you make such trade-offs.

[0092] The basic procedure used to establish the desired voltage range for implementing battery control is described in more detail below. In implementing battery control, the inventors of the present disclosure have recognized that by appropriately establishing a specific voltage range for an operating region exhibiting a relatively low internal resistance within the battery, the ohmic losses therein can be effectively reduced or minimized, and that such voltage range can even be adjusted accordingly based on changes in the amount of current detected during charging and / or discharging of the battery.

[0093] The prior art did not consider adjusting the voltage range to take into account changes in the amount of current. Therefore, through careful research and development activities, the inventors of the present disclosure concluded that the lack of proper adjustment to such voltage range contributed to the inefficiency of battery charging and / or discharging operations in the prior art. That is, the inventors of the present disclosure recognized that when a current above a certain level is applied to a battery using the prior art approach, the battery charging / discharging efficiency decreases. Based on this recognition of the specific problem, the inventors of the present disclosure devised an effective solution thereto in accordance with the embodiments described herein.

[0094] Figure 10 shows the pulse galvanostatic measurement curve and the internal resistance curve ((a) 20 mAg -1 , (b) 50mAg -1 , (c) 100mAg -1 , and (d) 200mAg -1 Some exemplary graphs of experimental results showing the determination of terminal discharge voltage at high current densities using (for

[0095] As a result, the method developed by the inventors of the present disclosure can be used to establish an optimal voltage range, and therefore battery charging and / or discharging operations are significantly improved compared to prior art charging and / or discharging methods.

[0096] Due to external or environmental factors as well as variations in the internal battery's electrochemical properties, all types of batteries can be in many different states depending on various operating conditions. Furthermore, there are only a limited number of values ​​or variables related to battery properties that can be measured without destroying or damaging the battery. For example, typical values ​​that can be measured include voltage, current, and resistance, and impedance, which is related to frequency, can also be measured. For lithium-based batteries and some lead-acid-based batteries, impedance measurements are used to assess battery life and capacity.

[0097] For vanadium-based batteries (e.g., vanadium-ion batteries (VIBs)), direct current (DC) and its voltage measurements are commonly used because they provide comparable results compared to those obtained through impedance measurements. It should be noted that for VIBs, DC-based measurements have been found to be more reliable because the liquid electrodes used there can have a specific effect on impedance measurements. The interrelationships or correlations between specific measurements (e.g., current, voltage, and resistance) can vary significantly or exhibit large variations due to temperature and other factors. Furthermore, the ion distribution (and other electrochemical properties) of the liquid electrodes within VIBs can cause changes and variations in their average voltage, which can be difficult to detect using external measurement equipment.

[0098] Accordingly, the inventors of the present disclosure have recognized a need or desire to "standardize" (i.e., normalize, codify, regulate, unify, harmonize, etc.) the state or condition (or specifications) of a VIB, taking into account certain factors such as temperature, ion distribution, etc. As a result, the inventors of the present disclosure have identified and determined that such standardized state or condition can be used to make more accurate voltage measurements, which in turn can be used to improve the battery charging and / or discharging operation of the VIB.

[0099] In the following, some additional technical background is provided to better understand the concepts and details of the embodiments contemplated by the inventors of the present disclosure. The inventors of the present disclosure have been able to identify and / or realize several interesting effects and / or results when conducting certain types of tests and experiments on VIBs.

[0100] Regarding the CC-CV curves, it was observed that as the battery charge amount (corresponding to CV control) increased, the OCV (for the same SoC value) was relatively low. That is, when the battery charge / discharge amount was low or the battery charge / discharge time increased (i.e., became longer), the OCV decreased.

[0101] According to the theory of the prior art, since the OCV is a value measured when the current is zero, it was thought that the OCV would not change depending on the amount of current. Figure 11 shows the SoC vs. OCV relationship for three different cases, namely, short-time charge, long-time charge / discharge, and short-time discharge, according to three graphs shown from top to bottom.

[0102] Based on these observations, the inventors of the present disclosure have concluded that there must be some elements with transient characteristics during the actual charging and / or discharging of a VIB, which means that certain methods or conditions are required for such elements to reach saturation.

[0103] Therefore, the inventors of the present disclosure believe that the aforementioned observations may be caused by the following: For a single battery cell of a vanadium-based battery (VIB or VRFB), the battery casing is essentially a container divided in half by a membrane, such that the first half-cell (e.g., for the cathode) contains a liquid electrode and a solid electrode along its inner wall, and the second half-cell (e.g., for the anode) contains a liquid electrode and a solid electrode along its inner wall. In such a structure, the so-called battery reaction takes place primarily on or near the carbon fiber surface of each solid electrode. The reasons for this are explained in more detail below.

[0104] Liquid electrodes are highly acidic and therefore have a large number of protons present within them. Such protons can migrate across the membrane and achieve electrical balance within the liquid electrode. Also, during charging and discharging, the ion distribution near the carbon fiber surface (in each solid electrode) differs from the ion distribution in other regions within the liquid electrode that are more distant from the carbon fiber surface (in each solid electrode). As a result, the oxidation state (or oxidation number) of vanadium ions within the liquid electrode differs depending on how close or far such vanadium ions are from the carbon fiber surface (in each solid electrode).

[0105] For example, vanadium ions near the solid cathode were observed to have an oxidation state closer to +2, while vanadium ions further from the solid cathode were observed to have an oxidation state closer to +3, and vanadium ions near the solid anode were observed to have an oxidation state closer to +5, while vanadium ions further from the solid anode were observed to have an oxidation state closer to +4.

[0106] Due to the current flow during charging and / or discharging, electrochemical (and / or electrical conductivity) battery reactions first occur in the liquid electrode region adjacent to the carbon fiber surface of each solid electrode (i.e., in the near-fiber region). Then, due to the electric field effects caused by ion diffusion and / or electrical imbalance, additional ions move or migrate as they diffuse or spread.

[0107] When constant current (CC) control is applied to a battery, the solid electrodes of the VIB are electrically connected to a constant current (which results in the same potential). Therefore, measuring the battery's OCV measures the potential corresponding to the surface concentration at the solid electrode. That is, external measurements of OCV for the VIB actually correspond to the potential present in the near-fiber region (i.e., on or near the carbon fiber surface of the solid electrode). However, such simple external measurements of OCV values ​​lack accuracy for the VIB because establishing the optimal voltage range to use for battery control during charge and / or discharge requires determining the "average SoC" for overall battery operation and measuring, calculating, or inferring specific relationships between various OCV-SoC values. That is, because the overall battery capacity of the VIB is obtained by multiplying the volume of the liquid electrodes within the VIB by the "average SoC," simply externally measuring the OCV value without considering other factors or applying other conditions will not produce the desired results.

[0108] Inherently, because VIBs employ liquid electrodes, the technical considerations and requirements involved in performing charge and / or discharge operations for vanadium-based batteries are quite different compared to the technical considerations and requirements for non-vanadium-based batteries (e.g., lithium-based batteries, lead-based batteries, etc.). As such, the inventors of the present disclosure have further recognized that several additional factors must also be considered in order to establish the optimal voltage ranges to use for battery control during charge and / or discharge for VIBs and the like.

[0109] In this respect, the condition of the battery is greatly affected by the ambient temperature. Therefore, proper evaluation of the battery requires that the ambient temperature be maintained at a relatively constant level. For example, the following points should be taken into consideration: Understanding the effect of ambient temperature on efficiency is important for ESS operation.

[0110] The energy efficiency of the VIB at various ambient temperatures was investigated. Figure 12 shows the effect of ambient temperature on the VIB performance, where (a) shows the energy efficiency and (b) shows the coulombic efficiency.

[0111] The energy efficiency under 1C-rate was measured at ambient temperatures ranging from -15°C to 50°C. where the battery discharge rate (C-rate) is expressed as: C-rate = (battery output corresponding to power consumption in a given time) In other words, 1C can be seen as the battery output when depleted in 1 hour.

[0112] It was found that the most favorable temperature range was between 25°C and 35°C, resulting in the highest energy efficiency of approximately 98.1%. Above 40°C, energy efficiency decreased slightly due to a decrease in Coulombic efficiency. Because the VIB has liquid electrodes, high temperatures accelerate the mixing of the liquid electrodes at the cathode and anode through the separation membrane, resulting in a decrease in Coulombic efficiency. Nevertheless, energy efficiency remained at approximately 97.3% even at 50°C.

[0113] The decline in energy efficiency was more severe at low temperatures. At relatively low temperatures, the liquid electrode becomes more viscous, slowing the chemical reaction, the charge transfer rate, and the diffusivity of vanadium ions. The decline in energy efficiency was gradual from approximately 25°C to 0°C, and the energy efficiency at 0°C still maintained 94.9%. However, the decline in energy efficiency became more severe below 0°C, dropping to 84.3% at -15°C. Heating the battery consumes energy in the ESS, reducing the overall energy efficiency of the ESS. However, heating the battery increases the energy efficiency of the battery, leading to higher energy efficiency of the ESS. Therefore, understanding the relationship between battery performance and operating temperature is important for efficient ESS operation.

[0114] In light of the above technical challenges and considering how a battery should be evaluated (based on its charging and / or discharging performance), the inventors of the present disclosure have considered how certain effects (caused by different current amounts) can be eliminated or suppressed, and how the effects of environmental temperature should be handled.

[0115] As a result, the inventors of the present disclosure have proposed several specific "standard conditions" under which vanadium-based batteries, such as VIBs, VRFBs, etc., should be evaluated or assessed. Such standardized conditions can also be used for quality control, analysis of abnormal system operation, battery reuse, and many other types of battery-related operations.

[0116] Energy efficiency measurements at 1 C-rate in an environmental temperature range of -15°C to 50°C can be considered the optimal C-rate conditions obtained by the inventors through research, development, and various experiments. However, the current inventors have confirmed that conditions using 0.5 C-rate or higher, or a range of 0.5 to 1.5 C-rates, also produce results that fall within the characteristics of the embodiments of the present disclosure. Because C-rate values ​​or ranges beyond the above findings may produce unsatisfactory experimental results, the inventors suggest the use of the above specific C-rate values ​​and ranges for at least some of the embodiments described herein.

[0117] With respect to standard conditions, battery evaluation should be: (1) performed at a constant or uniform temperature, (2) performed over a specific voltage range or area, and (3) performed after waiting for equilibrium to be achieved.

[0118] Furthermore, the estimation of the state of charge (SoC) value should also be performed under the standard conditions described above. Because external measurements that can be made on the battery are affected by the ambient temperature and the instantaneous current flowing through the battery, the effective elimination or suppression of such factors will enable more accurate SoC measurements.

[0119] FIG. 13 shows an example flow chart of a standard condition transition procedure for a vanadium-based battery according to at least some embodiments described herein. In step S1501, the vanadium-based battery enters a standard state.

[0120] In step S1503, the OCV is measured as shown, and more specifically, at least one of a voltage decrease (IR drop) and a voltage increase (IR rise) may be measured (S1513). During such measurements, the standard condition of the vanadium-based battery is maintained (S1512).

[0121] More specifically, in step S1511 after the previous step S1501, a constant temperature is set to be used for OCV measurement. Additionally, multiple voltage values ​​are set for a particular voltage range to be used for OCV measurement (S1511), and the standard state of the vanadium-based battery continues during OCV measurement, as shown in step S1512.

[0122] Through these procedures, at least one resistance value of the vanadium-based battery can be obtained (S1505), which is compared with a normal resistance value (S1507), and the state of the vanadium-based battery can be estimated based on the difference between the obtained resistance value and the normal resistance value.

[0123] Figure 14 illustrates an example device that can perform the steps of Figure 13 according to at least some embodiments described herein. Shown is an energy storage device 100 that can be connected to a power grid that can be divided into one or more so-called primary power domains and one or more so-called secondary power domains.

[0124] The energy storage device 100 may have an energy storage module 110 that includes a battery pack consisting of multiple battery modules and a module BMS (Battery Management System) that handles battery management functions for each battery module.

[0125] The controller 150 may use the power measurement results from the primary power domain and the secondary power domain to determine whether to charge or discharge the energy storage module 110. The controller 150 may also determine whether to discharge at least one of the one or more chargers located in the primary power domain and the secondary power domain.

[0126] The energy storage device 100 may include a pack BMS 120 that manages the charging and discharging of the energy storage module 110. The energy storage device 100 may also optionally include a PMS (power management system) 120 and a PCS (power conversion system) 140. When the energy storage device 100 has both a PMS 130 and a PCS 140, it may be referred to as a hybrid ESS.

[0127] Additionally, depending on how energy storage device 100 is installed or implemented, PMS 130 and PCS 140 may be physically separate devices from energy storage device 100. PMS 130 and PCS 140 may operate independently and may exchange data with energy storage device 100 through various communication means to provide operational control.

[0128] The batteries in each battery module of the energy storage device 100 can be charged with power or electricity via the PCS 140. The PCS 140 can receive power supply for storage in the batteries or can release power through a power line or system. Here, the PCS 140 can perform AC / DC conversion or convert the voltage or frequency being transmitted or received.

[0129] The PMS 130 exchanges information through communication with the PCS 140 and provides the PCS 140 with the information necessary to control the charging or discharging of the battery. The module BMS can manage the corresponding battery by monitoring the charging state, discharging state, temperature, voltage, current, etc. The pack BMS 120 is a battery management system for the entire battery pack.

[0130] The controller 150 and the PMS 130 may be combined or integrated and operate as a single entity, or the controller 150 may be a separate device.

[0131] In some embodiments, the controller 150 may be implemented within the PMS 130. As a further alternative, the PMS 130 may implement some or all of the functionality of the controller 150.

[0132] 13 , the energy storage device 100 may include a setting element configured to set a plurality of standard conditions related to the vanadium-based battery used in the method for evaluating the vanadium-based battery; and a measurement element configured to perform one or more measurements according to the set standard conditions related to the vanadium-based battery, where the standard conditions include a constant temperature, a plurality of voltage values ​​related to a specific voltage range, and an equilibrium state of the vanadium-based battery. For example, at least one of the setting element and the measurement element may be implemented in the controller 150, the PMS 130, or the module BMS. For example, the setting element and the measurement element may be implemented in hardware, software, or a combination thereof.

[0133] On the other hand, the portion 1605 shown in dotted lines handles battery management control and can be considered as the battery management component 1603 of the energy storage system (ESS). Such a battery management component 1603 is operatively connected to an energy storage component 1601, which may be comprised of one or more battery packs having multiple battery cells (cell 1, cell 2, ..., cell n), and is also connected to a discharger.

[0134] The battery management component 1603 has a measurement unit that performs measurements on various values ​​(Temp 1, Temp 2, Current, V1, Vn, etc.). Connected to the measurement unit are a capacity measurement unit, a state of charge unit, a state of health unit, a thermal management unit, etc., each performing a specific function. Additionally, there may be a cell balancing unit that performs cell balancing of the battery pack according to the measurements from the measurement unit. Finally, there may be a connectivity control unit, such as a CAN bus controller, that manages the connectivity with other elements.

[0135] FIG. 15 is a conceptual diagram of an exemplary semiconductor chip assembly according to at least one embodiment. The hardware handling battery management or control may be implemented on a printed circuit board (PCB: 1610) or the like including a semiconductor chip assembly or structure, the semiconductor chip, semiconductor chip assembly, or semiconductor chip structure including a memory 1612 or similar storage means and a processor 1614 or similar controller. The software and / or firmware necessary for such hardware for battery management and control may also be implemented to perform the various methods and features described with respect to the exemplary embodiments shown herein.

[0136] The characteristics of the embodiments of the present disclosure can also be explained as follows. It should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific implementations described above, which are disclosed by way of example only.

[0137] The present disclosure provides a semiconductor chip assembly, comprising: a memory containing information regarding transition of a vanadium-based battery to a standard state; and a processor operatively connected to the memory and configured to provide instructions or commands for transitioning the vanadium-based battery to a standard state, the standard state being transitioned to by setting a constant temperature to be used in performing an open circuit voltage (OCV) measurement and setting one or more voltage values ​​for a specific voltage range to be used in performing the OCV measurement, the processor further configured to provide instructions or commands for maintaining a balanced state of the vanadium-based battery while performing the OCV measurement.

[0138] The constant temperature is set within a range of 23°C with a deviation of plus or minus 2 degrees, and the one or more voltage values ​​are set so that the charge start voltage is approximately 1.0 to 1.2 V, and at least one additional voltage value is set so that it is greater than the charge start voltage and falls within a specific voltage range.

[0139] The equilibrium state of the vanadium-based battery is maintained by charging the vanadium-based battery to a particular charge level using a voltage set based on one or more voltage values, and performing constant voltage (CV) charging until a charge level corresponding to the nominal current is reached.

[0140] The processor further provides instructions or commands to perform an OCV measurement after CV charging has commenced. The specified charge level is about 0.5 C-rate or higher, with a nominal current of about 0.01 C-rate.

[0141] The OCV measurement is performed while the vanadium ion distribution within the vanadium-based battery is relatively uniform by maintaining an equilibrium state of the vanadium-based battery. The processor further provides instructions or commands to operate the vanadium-based battery within an OCV range of 1.2V to 1.6V.

[0142] The present disclosure also provides a method for semiconductor assembly, the method including: bringing a vanadium-based battery to a standard state by setting a constant temperature to be used in performing an open circuit voltage (OCV) measurement and setting a plurality of voltage values ​​for a specific voltage range to be used in performing the OCV measurement; and maintaining an equilibrium state of the vanadium-based battery while performing the OCV measurement.

[0143] The constant temperature is set within a range of 23°C with a deviation of plus or minus 2 degrees, and the one or more voltage values ​​are set so that the charge start voltage is approximately 1.0 to 1.2 V, and at least one additional voltage value is set so that it is greater than the charge start voltage and falls within a specific voltage range.

[0144] The equilibrium state of the VIB is maintained by charging the vanadium-based battery to a specific charge level using a voltage set based on one or more voltage values ​​and performing constant voltage (CV) charging until a charge level corresponding to the nominal current is reached.

[0145] The method further includes performing an OCV measurement after CV charging is initiated. The specified charge level is about 0.5 C-rate or higher, with a nominal current of about 0.01 C-rate.

[0146] The OCV measurement is performed while the vanadium ion distribution within the vanadium-based battery is relatively uniform by maintaining an equilibrium state of the vanadium-based battery. The method further includes operating the vanadium-based battery within an OCV range of 1.2V to 1.6V.

[0147] The present disclosure further provides a system having a semiconductor chip assembly, the system comprising: at least one energy storage component having a plurality of vanadium-based batteries arranged in a cell or pack; and a battery management component operatively connected to the energy storage component and configured to provide battery management control for transitioning the energy storage component to a standard state, the standard state being transitioned to by setting a constant temperature to be used in performing OCV measurements on the vanadium-based batteries arranged in the cell or pack and setting a plurality of voltage values ​​for specific voltage ranges to be used in performing OCV measurements on the vanadium-based batteries arranged in the cell or pack, the battery management component further configured to provide battery management control for maintaining a balanced state of the energy storage component, or at least one vanadium-based battery therein, while performing the OCV measurements.

[0148] The battery management component provides the following battery management controls to perform OCV measurements: a constant temperature is set within a range of 23°C with a deviation of plus or minus 2 degrees, one or more voltage values ​​are set such that the charge start voltage is approximately 1.0 to 1.2 V, and at least one additional voltage value is set greater than the charge start voltage and within a specific voltage range.

[0149] The equilibrium state of the vanadium-based batteries is maintained by charging at least one of the vanadium-based batteries to a particular charge level using a voltage set based on one or more voltage values, and performing constant voltage (CV) charging until a charge level corresponding to a nominal current is reached.

[0150] The battery management component provides battery management control to perform OCV measurements after CV charging is initiated, with a specific charge level being about 0.5 C-rate and a nominal current being about 0.01 C-rate.

[0151] The OCV measurement is performed while the vanadium ion distribution in at least one of the vanadium-based batteries is relatively uniform by maintaining an equilibrium condition in at least one of the energy storage components or the vanadium-based batteries.

[0152] The battery management component further provides battery management control for operating the energy storage component, or at least one vanadium-based battery therein, within an OCV range of 1.2V to 1.6V.

[0153] Unless the context clearly requires otherwise, throughout the description and claims, words like "comprise," "comprising," "include," "including," and the like, are to be construed in an inclusive sense, rather than an exclusive or exhaustive sense. That is, they mean "including, but not limited to." The word "coupled," as used generally herein, refers to two or more elements that are directly connected or connected through one or more intermediate elements. Similarly, the word "connected," as used generally herein, refers to two or more elements that are directly connected or connected through one or more intermediate elements. Furthermore, the words "herein," "above," "below," and words of similar import, when used in this application, refer to this application as a whole and not to specific portions of this application. Where the context permits, words appearing in the singular or plural sense as used in this disclosure may also include the plural or singular number, respectively. The word "or" in connection with a list of two or more items covers all of the following interpretations of the word: any item in the list, all items in the list, and any combination of items in the list.

[0154] Furthermore, conditional language used herein, such as "can," "could," "might," "may," "e.g.," "for example," "such as," and the like, is intended to generally convey that certain embodiments include certain features, elements, and / or conditions, while other embodiments do not, unless specifically stated otherwise or understood otherwise within the context in which it is used. Thus, such conditional language is generally not intended to imply that features, elements, and / or conditions are in any way required by one or more embodiments, or that these features, elements, and / or conditions are included in or performed in any particular embodiment.

[0155] While specific embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the disclosure. Indeed, the novel apparatus, methods, and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and changes in the form of the methods and systems described herein may be made without departing from the essential spirit of the disclosure. For example, while blocks are presented in a particular arrangement, alternative embodiments may perform similar functions with different components and / or circuit topologies and / or procedures, and some blocks may be deleted, moved, added, subdivided, combined, and / or modified. Each of these blocks may be implemented in a variety of different ways. Any suitable combination of elements and acts of the various embodiments described above may be combined to provide further embodiments. The various features and processes described above may be implemented independently of each other or combined in various ways. All possible combinations and subcombinations of features of the present disclosure are intended to be within the scope of this disclosure.

[0156] In this disclosure, the term "battery cell" refers to the smallest unit in which charging and discharging occurs through an electrolyte, and includes a membrane where ion exchange occurs, a separator, and the like. In this disclosure, the term "stack" means a stack or arrangement of multiple battery cells.

[0157] Vanadium-based batteries, such as vanadium redox batteries (VRBs), vanadium redox / flow batteries (VRFBs or VFRBs), vanadium flow batteries (VFBs), and vanadium-ion batteries (VIBs), are considered more promising for ESS / EES implementations and other applications related to the battery industry. These vanadium-based batteries share at least some of the advantages characteristic of RFBs. However, unlike conventional non-vanadium-based RFBs, vanadium-based batteries are significantly less flammable and less susceptible to damage due to the properties of the vanadium used in them.

Claims

1. 1. A semiconductor chip assembly comprising: A memory containing information regarding the transition of the vanadium-based battery to a standard state; and a processor operatively connected to the memory and configured to provide instructions or commands for transitioning the vanadium-based battery to a standard state, the standard state being transitioned to by establishing a constant temperature to be used in performing an open circuit voltage (OCV) measurement and establishing one or more voltage values ​​for a particular voltage range to be used in performing the OCV measurement; The semiconductor chip assembly, wherein the processor is further configured to provide instructions or commands for maintaining a balanced state of the vanadium-based battery while performing OCV measurements.

2. 10. The assembly of claim 1, The constant temperature is set within a range of 23°C with a deviation of plus or minus 2°C; The assembly, wherein the one or more voltage values ​​are set such that a charge start voltage is 1.0 to 1.2 V, and the at least one additional voltage value is greater than the charge start voltage and within a specific voltage range.

3. 3. The assembly of claim 2, wherein the equilibrium state of the vanadium-based battery is: charging the vanadium-based battery to a particular charge level using a voltage set based on the one or more voltage values; The assembly is maintained by performing a constant voltage (CV) charge until a charge level corresponding to the nominal current is reached.

4. 4. The assembly of claim 3, wherein the processor further provides instructions or commands to perform an OCV measurement after CV charging is initiated.

5. 5. The assembly of claim 4, wherein the specified charge level is greater than or equal to 0.5 C-rate and the nominal current is 0.01 C-rate.

6. 5. The assembly of claim 4, wherein the OCV measurement is performed while the vanadium ion distribution within the vanadium-based battery is relatively uniform by maintaining an equilibrium state of the vanadium-based battery.

7. 10. The assembly of claim 1, wherein the processor further provides instructions or commands to operate the vanadium-based battery within an OCV range of 1.2V to 1.6V.

8. 1. A method for semiconductor chip assembly, the method comprising: Bringing the vanadium-based battery to a standard state by establishing a constant temperature to be used in performing an open circuit voltage (OCV) measurement and establishing one or more voltage values ​​for a particular voltage range to be used in performing the OCV measurement; and A method comprising maintaining a balanced condition of a vanadium-based battery while performing an OCV measurement.

9. 9. The method of claim 8, The constant temperature is set within a range of 23°C with a deviation of plus or minus 2°C; The one or more voltage values ​​are set so that a charge start voltage is 1.0 to 1.2 V, and at least one additional voltage value is set so that it is greater than the charge start voltage and falls within a specific voltage range.

10. 10. The method of claim 9, wherein the equilibrium state of the vanadium-based battery is: charging the vanadium-based battery to a particular charge level using a voltage set based on the one or more voltage values; The method is maintained by performing constant voltage (CV) charging until a charge level corresponding to the nominal current is reached.

11. 1. A system having a semiconductor chip assembly, the system comprising: At least one energy storage component having a plurality of vanadium-based batteries arranged in a cell or pack; and a battery management component operatively connected to the energy storage component and configured to provide battery management control for transitioning the energy storage component to a standard state; The standard state is entered by setting a constant temperature to be used in performing OCV measurements on the vanadium-based batteries arranged in a cell or pack, and setting one or more voltage values ​​for a specific voltage range to be used in performing OCV measurements on the vanadium-based batteries arranged in a cell or pack; The battery management component is further configured to provide battery management control for maintaining a balanced state of the energy storage component, or at least one vanadium-based battery therein, while performing OCV measurements.

12. 12. The system of claim 11, wherein the battery management component provides the following battery management controls for performing OCV measurements: The constant temperature is set within a range of 23°C with a deviation of plus or minus 2°C; The one or more voltage values ​​are set such that a charge start voltage is 1.0 to 1.2 V, and the at least one additional voltage value is greater than the charge start voltage and within a specific voltage range.

13. 13. The system of claim 12, wherein the equilibrium state of the vanadium-based battery is: charging at least one of the vanadium-based batteries to a particular charge level using a voltage set based on the one or more voltage values; The system is maintained by performing constant voltage (CV) charging until a charge level corresponding to the nominal current is reached.

14. 14. The system of claim 13, wherein a battery management component provides battery management control for performing OCV measurements after CV charging is initiated, the specified charge level being greater than or equal to 0.5 C-rate, and the nominal current being 0.01 C-rate.

15. 12. The system of claim 11, wherein the battery management component further provides battery management control for operating the energy storage component, or at least one vanadium-based battery therein, within an OCV range of 1.2V to 1.6V.

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