Cell quality inspection of aqueous battery and cell block manufacturing based on same

Abstract

The present document relates to a quality inspection method for a cell of an aqueous battery, a device therefor, and a method and a system for manufacturing a cell block on the basis of same. To this end, the method for manufacturing a cell block of an aqueous battery includes: stacking cells including a plurality of layers; injecting a liquid electrode into each of a plurality of cells in which the cells are stacked; performing primary quality control by applying power in a state where the plurality of cells are electrically connected; selecting cells having a quality equal to or greater than a predetermined reference according to a result of the primary quality control; and re-stacking the selected cells to manufacture the cell block.

Description

Cell quality inspection of aqueous batteries and cell block manufacturing based on the same

[0001] The following description relates to quality control of aqueous batteries, specifically, to a method for inspecting the quality of each cell of an aqueous battery, a device therefor, and a method for manufacturing a cell block based on the same.

[0002] Secondary batteries, unlike primary batteries, which are non-rechargeable, are rechargeable and dischargeable. These secondary batteries are used in a variety of fields, including portable devices like cell phones and laptops, as well as electric vehicles and energy storage systems (ESS).

[0003] Among these secondary batteries, the most popular type is lithium secondary batteries, which have a larger capacity than nickel-cadmium or nickel-hydrogen batteries and a higher energy density per unit weight, so their utilization is rapidly increasing.

[0004] These lithium secondary batteries primarily use lithium oxide and carbon materials as the positive and negative electrode active materials, respectively. Lithium secondary batteries comprise an electrode assembly comprising positive and negative plates coated with the positive and negative electrode active materials, respectively, with a separator interposed between them, and an outer case that seals and encloses the electrode assembly together with an electrolyte.

[0005] Secondary batteries are generally manufactured by injecting a liquid electrolyte, i.e., an electrolyte solution, into a battery case while the electrode assembly is housed in the battery case, and sealing the battery case.

[0006] These lithium secondary batteries can experience various types of defects due to various causes during the manufacturing process or during use. In particular, some manufactured secondary batteries exhibit a voltage drop exceeding the self-discharge rate, a phenomenon known as low voltage.

[0007] These low-voltage defects in secondary batteries are often caused by internal metallic foreign matter. Specifically, if a metallic foreign matter, such as iron or copper, is present on the positive electrode of a secondary battery, it can grow into dendrites on the negative electrode. These dendrites can cause internal short circuits in the secondary battery, leading to battery failure, damage, or, in severe cases, fire.

[0008] Until now, various technologies have been proposed to inspect low-voltage defects in these secondary batteries.

[0009] For example, Korean Patent No. 2194845 (registered on December 17, 2020) proposes a method for quickly detecting low-voltage defects in the secondary battery described above.

[0010] In addition, Korean Patent Publication No. 2021-0048327 (published on May 3, 2021) discloses a method for inspecting defective secondary electrodes, a method for identifying and removing defective electrodes, etc.

[0011] However, the quality inspection method for secondary batteries as described above only suggests a quality inspection method centered on lithium secondary batteries, and is unsuitable as a quality inspection method for aqueous batteries that utilize liquid electrodes because it does not take into account the characteristics of aqueous batteries.

[0012] In order to solve the above-described problem, one aspect of the present invention proposes a quality inspection method for a cell unit of an aqueous battery, a device therefor, and a method for manufacturing a cell block based thereon.

[0013] In addition, in a preferred embodiment of the present invention, considering that a full inspection of each cell is required in an aqueous battery, a method of manufacturing a cell block is proposed by stacking cells to include an electrode for inspection in a plurality of layers, removing defective cells based on cell quality control (QC), and then re-stacking cells having a quality higher than a predetermined standard.

[0014] In addition, in a preferred embodiment of the present invention, a specific procedure for performing cell QC is stipulated, and a standard for verifying cell quality for each procedure is presented.

[0015] In addition, in a preferred embodiment of the present invention, a quality control circuit device for efficiently performing cell QC is proposed.

[0016] In addition, in a preferred embodiment of the present invention, a procedure and quality criteria for performing subsequent quality inspection on a cell block unit that has been re-stacked after going through cell QC are proposed.

[0017] The problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0018] In one aspect of the present invention for solving the above-described problem, a method for manufacturing a cell block of an aqueous battery using a liquid electrode is proposed, comprising: stacking cells including a plurality of layers; injecting the liquid electrode into each of a plurality of cells in which the cells are stacked; performing a first quality control by applying power while the plurality of cells are electrically connected; selecting cells having a quality higher than a predetermined standard according to the first quality control result; and re-stacking the selected cells to manufacture the cell block.

[0019] In another aspect of the present invention, a system for manufacturing a cell block of an aqueous battery based on a cell quality inspection using a liquid electrode is proposed, comprising: a cell stacking unit configured to stack cells including a plurality of layers; a liquid electrode injector configured to inject the liquid electrode into each of the plurality of cells stacked in the cell stacking unit; and a quality control circuit device that performs the cell quality inspection by applying power while the plurality of cells are electrically connected, wherein the cell stacking unit is further configured to select cells having a quality equal to or higher than a predetermined standard based on a result of the cell quality inspection of the quality control circuit device, and to re-stacking the selected cells to manufacture the cell block.

[0020] Meanwhile, in another aspect of the present invention, a method for performing cell quality inspection of an aqueous battery using a liquid electrode is proposed, comprising: performing a first CC (Constant Current) charge for performing fast charging at a first reference current or higher on a plurality of stacked cells; performing a second CC charge for performing slow charging at a second reference current or lower after the first CC charge; applying a rest period for inducing self-discharge for a third reference or higher period after the second CC charge; and performing a discharge for discharging the plurality of cells at a SoC (State of Charge) or lower after the rest period.

[0021] In another aspect of the present invention, a quality control circuit device for performing cell quality inspection of an aqueous battery using a liquid electrode is proposed, comprising: a power supply in which a positive electrode is connected to a first inspection electrode of a first cell among N cells connected in series, and a negative electrode is connected to a second inspection electrode of an Nth cell; a relay configured to disconnect the power supply when an idle period is applied; a timer connected to the power supply and the relay to perform time-based control; and a BMS (Battery Management System) performing voltage logging according to the time of the timer, wherein the power supply is configured to change a current value when switching between a first CC (Constant Current) charge that performs fast charging of the N cells with a current equal to or higher than a first reference current, and a second CC charge that performs slow charging with a current equal to or lower than a second reference current after the first CC charge.

[0022] In one embodiment of the present invention, stacking the cells can be performed by including an inspection electrode on the outside of the plurality of layers.

[0023] Additionally, it is preferable that the injection of the liquid electrode is performed after compressing the stacked plurality of cells.

[0024] Additionally, in the first quality control, it is preferable that the plurality of cells are connected in series and a constant current (CC) is applied.

[0025] In one embodiment of the present invention, after performing the first CC charging, cells among the plurality of cells that do not meet the criteria of being below the lower voltage limit, exceeding the upper voltage limit, or exceeding the OCV upper limit can be selected as cells having a quality higher than the predetermined criteria.

[0026] At this time, if the idle period start voltage is 1.430 V or less or 1.480 V or more, the cell may not be selected as a cell having a quality higher than the above-mentioned standard.

[0027] More preferably, when the idle period start voltage is 1.447 V or less or 1.460 V or more, the cell is preferably not selected as a cell having a quality higher than the predetermined standard.

[0028] Additionally, during the above-described rest period, cells that do not self-discharge beyond the upper limit of voltage change among the plurality of cells can be selected as cells having a quality higher than the predetermined standard.

[0029] In the above-described embodiments, the first criterion may be determined in consideration of the limit value of the quality control circuit device, and the second criterion may be determined in consideration of electrolyte stabilization.

[0030] Additionally, the third criterion may be set to a maximized time interval considering the aqueous battery manufacturing cycle, and the fourth criterion may be determined considering disassembly into cell units for re-stacking.

[0031] In a preferred embodiment of the present invention, the method may further include performing a second quality control on the manufactured cell block, wherein the second quality control may include performing charging and discharging on the cell block a predetermined number of times.

[0032] Specifically, the second quality control may include a cell stabilization step including completely discharging undischarged cells in the first quality control; a cell block internal resistance measurement step performing charging and discharging through high current; a step inducing complete discharge through discharging through low current; a step measuring the charging current amount through charging and discharging according to a standard cycle after the complete discharge; and a step of completely charging the cell block.

[0033] At this time, the second quality control can be performed through a universal charger / discharger.

[0034] In one embodiment of the present invention, re-stacking the cells may include, after performing the first quality control, disassembling the plurality of cells into cell units; classifying the types of cells having a quality higher than the predetermined standard according to at least one element of charge performance and discharge performance; and grouping the cells according to the classified types and performing re-stacking.

[0035] In one embodiment of the present invention, the plurality of layers may include a separator, a pair of solid electrodes positioned at opposite ends of the outer surface of the separator, and a pair of current collectors positioned on the outer side of each of the pairs of solid electrodes, and the inspection electrode may be positioned on the outer side of each of the pairs of current collectors.

[0036] In addition, a frame having a predetermined thickness is placed on the left and right sides of the solid electrode pair, and it is preferable that the predetermined thickness is determined according to the degree of compression of the plurality of cells.

[0037] In addition, the horizontal area of ​​the frame can be set so that the combined horizontal area of ​​the frame and the solid electrode corresponds to the horizontal area of ​​the current collector.

[0038] In addition, the inspection electrode may have a thickness greater than or equal to a first thickness determined to prevent deformation of the current collector due to injection of the liquid electrode, and preferably, the inspection electrode may be made of 3T aluminum.

[0039] In the embodiments described above, the aqueous battery may include a VIB (Vanadium Ion Battery), and in this case, the cell block may correspond to a mono block of the VIB, but is not limited thereto, and the method described above may be applied to various aqueous batteries.

[0040] According to the embodiments of the present invention as described above, a method for quality inspection of cells of an aqueous battery and a device therefor, and a method and system for manufacturing cell blocks based thereon can be efficiently implemented.

[0041] Specifically, in a preferred embodiment of the present invention, considering that a full inspection of each cell is required in an aqueous battery, a defect-free cell block can be manufactured by stacking cells to include inspection electrodes in multiple layers, removing defective cells based on cell QC, and then re-stacking cells having a quality higher than a predetermined standard.

[0042] In addition, in a preferred embodiment of the present invention, specific procedures for performing cell QC are prescribed, and criteria for verifying cell quality for each procedure are presented, so that defective cells can be accurately excluded.

[0043] In addition, in a preferred embodiment of the present invention, a quality control circuit device for efficiently performing cell QC is proposed, so that the procedure can be performed in accordance with the characteristics of the above-described cell QC.

[0044] In addition, in a preferred embodiment of the present invention, a procedure and quality standards for performing subsequent quality inspections on re-stacked cell block units after cell quality inspection are specifically presented, thereby providing a higher level of finished product.

[0045] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0046] Figure 1 is a drawing for explaining VRFB.

[0047] FIG. 2 is a drawing for explaining VIB as a water-based battery according to one embodiment of the present invention.

[0048] FIG. 3 is a drawing for explaining why a full investigation is necessary for quality control of VIB according to one embodiment of the present invention.

[0049] FIG. 4 is a drawing for explaining a method for manufacturing a cell block of an aqueous battery utilizing a liquid electrode according to one embodiment of the present invention.

[0050] FIG. 5 is a drawing for explaining a method of manufacturing a monoblock of VIB using the embodiment described above with respect to FIG. 4.

[0051] FIG. 6 is a drawing for explaining a specific method of performing the first QC according to one embodiment of the present invention.

[0052] FIG. 7 is a drawing for explaining a quality control circuit device for performing cell quality inspection according to one embodiment of the present invention.

[0053] FIG. 8 is a diagram for explaining the concept of performing re-stacking using cells that have passed QC criteria according to one embodiment of the present invention.

[0054] FIG. 9 and FIG. 10 are drawings for explaining the concept of performing a second QC according to one embodiment of the present invention.

[0055] FIG. 11 is a drawing for explaining each step of the second QC according to one embodiment of the present invention.

[0056] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in the drawings, parts irrelevant to the description have been omitted to clearly explain the present invention, and similar parts have been designated with similar reference numerals throughout the specification.

[0057] Throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0058]

[0059] As described above, in one aspect of the present invention, a quality inspection method for a cell of an aqueous battery is proposed.

[0060] There are various types of batteries using liquid electrodes, including VRFB (Vanadium Redox Flow Battery) and VIB (Vanadium Ion Battery) developed by the applicant, as well as aqueous zinc secondary batteries using water-based electrolytes.

[0061] Among various water-based batteries, the VRFB and VIB developed by the applicant are briefly described below.

[0062] Figure 1 is a drawing for explaining VRFB.

[0063] As illustrated in FIG. 1, the VRFB may include a stack (1) of vanadium-based battery cells, a positive electrode electrolyte tank (2), a negative electrode electrolyte tank (3), and a pump (4) as its basic components.

[0064] The stack (1) has a structure in which unit cells (6) are stacked as shown on the right, and the unit cells (6) may have a structure in which electrodes (9) are formed on both sides with a separator (8) in between, and a current collector (7) is arranged surrounding the electrodes (9).

[0065] In this structure, the structure that generates current is explained. First, the electrolyte (S110) in the electrolyte tank (3) is used to generate a flow of electrolyte (S120) using a pump (4), and this flow of electrolyte moves (S140) to the battery stack (1) through a pipe (S130).

[0066] A battery that generates current by returning the electrolyte to the tank after a vanadium redox reaction occurs within the battery stack (1) can be viewed as a VRFB.

[0067] However, in the case of the VRFB described above, there are problems such as energy consumption of the pump (4), imbalance of ions in the tank (2, 3), occurrence of electrode resistance due to uneven flow of electrolyte, and problems with planted pipelines, which result in reduced energy efficiency.

[0068] FIG. 2 is a drawing for explaining VIB as a water-based battery according to one embodiment of the present invention.

[0069] Referring to FIG. 2, the structurally most significant difference from the VRFB described in FIG. 1 is the absence of a pump (3). Instead, in some embodiments, the VIB (200A) is configured such that the first and second electrolytes can be ion-relocated within the positive electrolyte receptacle (106A) of the first half-cell (204A) and the negative electrolyte receptacle (106B) of the second half-cell (204B), respectively. Various structural modifications are possible, and the ion-relocation is possible because of: an osmotic pressure difference between the two receptacles (106A, 106B); a density change in one or both of the first and second electrolytes; diffusion or migration of one or both of the first and second electrolytes; first and second redox half reactions; and / or expansion or contraction of one or both of the first and second electrolytes due to temperature.

[0070] The inventors have recognized that sufficient stability and power supply and energy output for the VIB can be provided if the cross-sectional thickness of the positive and negative electrolyte receiving portions (106A, 106B) does not exceed a specific value, for example, 20 cm, 15 cm, 10 cm, 5 cm, 2 cm, 1 cm, or a range defined by these values.

[0071] A VIB implemented in this manner can offer various technical and commercial advantages. For example, it can minimize or eliminate failures or reliability issues arising from passages such as pipe / tube joints between the battery cells and the receiving compartment (tank), as well as malfunctions / malfunctions of pumps used to circulate the electrolyte, thereby reducing the need for repairs, safety issues, and operating costs associated with the operation of the VIB (200A). Furthermore, since there is no need for a pump to circulate the electrolyte between the battery cells and the receiving compartment (tank), overall efficiency can be improved.

[0072] The present inventors have discovered that the use of a VIB (200A) can increase power or energy density by 2 to 50 times, depending on its size, by eliminating the electrolyte circulation between battery cells and electrolyte tanks required in the VRFB described above with reference to FIG. 1. As described above, power or energy density refers to the power or energy density output relative to the total volume of the energy storage device. Therefore, in the case of a VIB, power or energy density refers to the ratio of the total capacity of the VIB to the power or energy output. In addition, since separate equipment such as tanks, pumps, and circulation pipes required for the electrolyte circulation system are not necessary, the space occupied by the energy storage device can also be significantly reduced.

[0073] Additionally, the overall system complexity can be significantly reduced, thereby eliminating the limitations of commercial applications of VRFBs. For example, unlike the VRFB of Fig. 1, the VIB (200A) can be manufactured in a pack form, similar to lithium-ion batteries, making it suitable for automated processes and mass production, and eliminating the cumbersome construction required to install the VRFB of Fig. 1.

[0074] The following describes the general operating principles and characteristics of a redox battery, using a VIB based on vanadium-based redox pairs as an example. However, embodiments of the present invention are not limited thereto, and it will be appreciated that the principles described below are applicable to other types of redox batteries utilizing other types of redox pairs.

[0075]

[0076] As described above, a liquid electrode can be accommodated in the positive electrolyte receiving portion (106A) and the negative electrolyte receiving portion (106B). A separator (112; membrane) is arranged between these electrolyte receiving portions (106A and 106B), and as described below, it can be seen that protons move between the separators (112) to maintain electrical balance between the electrolytes.

[0077] The liquid electrode contains ions in which a redox (i.e., oxidation-reduction) reaction occurs. The first liquid electrode is an electrolyte in which an anode redox couple is dissolved. The anode redox couple can be implemented with a material including at least one of transition metals such as titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), or zinc (Zn), bromine (Br), and cesium (Cs), and the electrolyte of the present embodiments includes vanadium (V) and V. 2+ / V 3+ The redox couple is dissolved.

[0078] The first liquid electrode may be an acidic aqueous solution that conducts current through ionization, preferably containing sulfuric acid.

[0079] In this embodiment, the first liquid electrode can be manufactured by dissolving VOSO4 (vanadylsulfate), V2O5 (vanadium pentoxide) or other suitable substances in an H2SO4 aqueous solution.

[0080] The first liquid electrode causes the first half-reaction. The first half-reaction is as shown in [Mathematical Formula 1] below, where the right arrow (→) indicates the direction of the discharge reaction and the left arrow (←) indicates the direction of the charge reaction.

[0081] [Mathematical Formula 1]

[0082] V 2+ ←→V 3+ + e-

[0083] In the relationship described above, vanadium divalent ions are oxidized to vanadium trivalent ions during discharge, and vanadium trivalent ions are reduced to vanadium divalent ions during charge.

[0084] Meanwhile, the second liquid electrode is an electrolyte in which the cathode redox couple is dissolved, and in the present embodiments, V 4+ / V 5+ Redox couples may exist.

[0085] The second liquid electrode causes the second half-reaction. The second half-reaction is as shown in [Mathematical Formula 2] below, where the right arrow (→) indicates the direction of the discharge reaction and the left arrow (←) indicates the direction of the charge reaction.

[0086] [Equation 2]

[0087] V 5+ + e - ←→V 4+

[0088] At this time, during discharge, vanadium pentavalent ions are reduced to vanadium tetravalent ions, and during charge, vanadium tetravalent ions are oxidized to vanadium pentavalent ions.

[0089]

[0090] For aqueous batteries including VRFB and VIB as described above, it is desirable to manufacture cell blocks by performing a full inspection, unlike lithium-ion batteries.

[0091] This is explained using the VIB described above as an example.

[0092] FIG. 3 is a drawing for explaining why a full investigation is necessary for quality control of VIB according to one embodiment of the present invention.

[0093] As illustrated in FIG. 3, carbon fibers (310) are randomly oriented between the separators (112) in the VIB. Since the battery reaction of the VIB primarily occurs on the surface of the carbon fibers (310) of the solid electrode, such random arrangement of the carbon fibers (310) can result in significant deviations in their respective physical properties.

[0094] In this regard, it may be considered to perform quality control to the extent of measuring the surface density to roughly determine the physical properties and excluding only some outliers, but due to the problem that the surface activity (hydrophilicity) varies depending on the degree of surface treatment, and thus the internal fluid resistance varies, a full inspection is desirable for quality control (QC).

[0095] Furthermore, the need for a comprehensive investigation in the QC of VIBs can also be explained by the use of liquid electrodes. In VIBs, the amount of liquid electrodes is directly related to the VIB capacity, so inserting the correct amount of liquid electrodes into each cell can be a key aspect of QC.

[0096] Additionally, because liquids with a higher viscosity than water must be forced into narrow cells, there is a possibility of capacity variations from cell to cell.

[0097] Due to these and other adverse factors, a preferred embodiment of the present invention proposes to conduct a full-scale investigation and grading of aqueous batteries such as VIBs and manufacture cell blocks (monoblocks in the case of VIBs) only from cells that meet or exceed a predetermined quality standard.

[0098]

[0099] FIG. 4 is a drawing for explaining a method for manufacturing a cell block of an aqueous battery utilizing a liquid electrode according to one embodiment of the present invention.

[0100] The method according to the present embodiment can first stack cells including multiple layers (S410). If a system for manufacturing cell blocks of an aqueous battery is configured, a cell stacking unit can be configured as a configuration in which such cell stacking is performed, and such cell stacking unit can also be utilized for cell re-stacking as described below.

[0101] Here, the 'layer' may correspond to a separator, a solid electrode, a current collector, etc. in the VRFB and VIB described above with respect to FIGS. 1 and 2, and in one embodiment of the present invention, it is proposed to perform stacking by including an inspection electrode for performing the first QC described later in each cell.

[0102] Thereafter, the above-mentioned cell may be compressed into a plurality of stacked cells (S420), and the liquid electrode may be injected into each of the compressed plurality of cells (S430). However, the compression (S420) procedure may be omitted depending on the cell type applied, but for the convenience of explanation, the following description will be made taking into account the battery type in which the compression (S420) procedure is performed.

[0103] If a system for manufacturing cell blocks of a water-based battery is configured, it is desirable to include an injector for injecting such liquid electrodes.

[0104] At this time, it is necessary to prevent changes in the volume within the layer due to the pressure of the liquid electrode solution or deformation of the current collector. In a preferred embodiment of the present invention, it is proposed to perform this function by forming the inspection electrode with a thick metal. For example, the inspection electrode may be composed of 3T aluminum, but the specific dimensions need not be limited thereto.

[0105] Meanwhile, after the liquid electrode is injected (S430) in this manner, it is proposed to perform the first QC (S440) by applying power while the plurality of cells are electrically connected. The first QC may be referred to as cell QC or cell unit QC, and needs to be distinguished from the second QC (cell block QC) performed after the formation of a cell block described below.

[0106] In one embodiment of the present invention, the first QC is proposed to be performed in such a manner that a plurality of cells are connected in series and a constant current (CC) is applied.

[0107] If, in the first QC, the cells are configured in parallel connection / constant voltage, it may be difficult to compare them because the currents between the cells differ. In particular, in the case of the parallel connection / constant voltage configuration, the presence of defective cells or cells without liquid electrode injection will affect the current values ​​of other cells.

[0108] In contrast, when applying a series connection / constant current as in this embodiment, a uniform current is applied between cells, which has the advantage of making it easy to compare them. If there is a cell without a liquid electrode injection or a defective cell, it is preferable to configure a circuit device described below so that the cell is bypassed.

[0109] In this embodiment, it is proposed to select cells having a quality higher than a predetermined standard based on the first QC results (S450), and to manufacture the cell block by re-stacking the selected cells (S460). That is, it is proposed to manufacture the cell block by performing a first QC inspection on each cell, disassembling the cells into units, and then re-stacking only the non-defective cells.

[0110] In addition, in one embodiment of the present invention, the above-described re-stacking (S460) may be set to perform re-stacking by disassembling a plurality of cells into cell units after performing the first QC (S440), classifying cells that have passed the first QC (S440) with a quality higher than a predetermined standard into types based on one or more elements of charge performance and discharge performance, and grouping the cells according to the classified types.

[0111] The "re-stacking (S460)" performed in the embodiment of the present invention as described above can be seen as a distinguishing feature between the embodiment in which VIB is utilized and the example in which VRFB or LIB is applied.

[0112] For example, when using VRFB, once a cell layer is stacked, it is difficult to disassemble it into cell units and perform re-stacking, as damage to the cells may occur during the disassembly process.

[0113] On the other hand, when using LIB, there is a difference in that a separate stacking is not performed to perform cell QC (the first QC above), but rather a single stacking is performed using cells that have a quality higher than a predetermined standard after completing QC.

[0114] FIG. 5 is a drawing for explaining a method of manufacturing a monoblock of VIB using the embodiment described above with respect to FIG. 4.

[0115] First, FIG. 5 illustrates a form in which the cell stacking (S410) of the embodiment of FIG. 4 is applied to a VIB. Specifically, each cell for the VIB may include a plurality of layers including a separator (510), a solid electrode pair (520) positioned at both ends on the outside of the separator (510), and a current collector pair (530) positioned on the outside of each of the solid electrode pairs (520), and a test electrode (540) positioned on the outside thereof.

[0116] In addition, a frame (550) having a predetermined thickness is placed on the left and right sides of the solid electrode pair (520), and the predetermined thickness at this time may be determined depending on the degree of compression of the plurality of cells in the subsequent step S420.

[0117] In addition, the horizontal area of ​​the frame (550) may be set so that the combined horizontal area of ​​the frame (550) and the solid electrode (530) corresponds to the horizontal area of ​​the current collector (530). According to step S420 of FIG. 5, the above configuration can serve to minimize deformation of the current collector (530) during compression.

[0118] Meanwhile, step S430 of FIG. 5 illustrates a concept in which a liquid electrode (560) is injected into each electrode of the VIB. At this time, as described above, the inspection electrode (540) preferably has a thickness greater than the first thickness determined to prevent deformation of the current collector (530) due to injection of the liquid electrode (560), and in one embodiment of the present invention, it is assumed that the inspection electrode is made of 3T aluminum.

[0119] Meanwhile, in order to perform cell stacking (S410), an end plate (570) may be placed on the upper side of the first cell and the lower side of the Nth cell among the N cells, and it is preferable to configure the end plate (570) so that the compressive force can be uniformly transmitted throughout the layer when compressed.

[0120]

[0121] FIG. 6 is a drawing for explaining a specific method of performing the first QC according to one embodiment of the present invention.

[0122] As illustrated in FIG. 6, the first QC (cell QC) may include performing a first CC charge (S610) for fast charging a plurality of cells with a current equal to or higher than a first reference, performing a second CC charge (S620) for slow charging with a current equal to or lower than a second reference after the first CC charge (S610), applying a rest period (S630) for inducing self-discharge for a period equal to or higher than a third reference after the second CC charge (S620), and discharging the plurality of cells with a SoC (State of Charge) equal to or lower than a fourth reference after the rest period (S630). An rest period for switching / OCV measurement may additionally be included between each of the above-described steps (S610 - S640).

[0123] The meaning of each step (S610 - S640) is described in detail below. To facilitate understanding, a specific example of applying the first QC procedure described above to a VIB stacked with 32 cells, as shown in [Table 1], is provided.

[0124] Applied current (A) Time required (s) Reached voltage (V) 1 st CC1.8860001.46~1.53 (9p.)2 nd CC0.07521600~1.46REST043200△V≒ several mV discharge-2.25400~1.2

[0125] In the above [Table 1], the applied current (A) and required time (s) can be viewed as fixed variables, and the reached voltage (V) can mean a measured value. The first CC charge (S610) described above can be viewed as a process of separating the 3.5-valent electrolyte into 4-valent for each positive electrode and 3-valent for each negative electrode. In this process, additional energy other than general charge / discharge may be input.

[0126] For a specific example based on [Table 1], in the first CC charge (S610) performing fast charging, the first standard, which is the standard for fast charging current, may be 1.88 A (= 0.85C = 2.2 A * 0.85), but this is a standard determined in consideration of the limit of the device used for fast charging ('quality control circuit device' described later), and if the performance of the device allows, a current higher than 1C may be used.

[0127] As an example of [Table 1], one embodiment of the present invention proposes to continue the first CC charging for up to 6000 seconds. Since charging is performed for 6000 seconds, the charging current at this time can correspond to 3.13 Ah, and 0.45 Ah can be additionally charged in the second CC charging (S620) step described later.

[0128] For VIB, the cell capacity is 2.2 Ah, so approximately 1.38 Ah can be seen as being used for electrolyte separation.

[0129] The cell status can be confirmed by measuring the voltage reached after the completion of the first CC charge (S610) described above. The voltage reached can be affected by the cell internal resistance and cell energy capacity.

[0130] That is, high cell internal resistance can be confirmed through a high charge termination voltage, and high cell energy capacity can be confirmed through a low SOC at charge termination, and also through a low charge termination voltage.

[0131] Therefore, it is important that the voltage reached after the completion of the first CC charge (S610) described above falls within a certain range. By comparing the charge termination voltage with the voltage in the idle state between the first CC charge (S610) and the second CC charge (S620), it is possible to measure the internal resistance of the cell, which can be used for root cause analysis when a problem occurs.

[0132] That is, in one embodiment of the present invention, it is proposed to select cells that do not meet the criteria of lower voltage limit, upper voltage limit, or OCV upper limit among a plurality of cells after performing the first CC charging (S610) as cells having a quality higher than the predetermined criteria. These criteria are shown in [Table 2] below based on specific examples applied to VIB. The criteria in [Table 2] below are criteria determined by considering a specific yield based on statistical grounds, and different criteria may be applied if the set yield is different.

[0133] Type 1 Type 2 Lower limit Upper limit Lower limit Upper limit 1 st CC End Voltage 1.46 V1.50 V1.48 V1.53 VOCV drop (Rest start ↔ end voltage difference) N / A 12mV N / A 12mV

[0134] As shown in the above [Table 2], in one embodiment of the present invention, after the above-described first CC charging (S610) is completed, it is proposed that the criteria for falling short of the lower limit voltage and exceeding the upper limit voltage be set differently depending on the first type cell or the second type cell. For example, it is preferable to set the first type cell to be a cell with good charge performance and the second type cell to be a cell with good discharge performance, so that the re-stacking described below is performed for each type of cell. However, the first type (charge performance) and the second type (discharge performance) described above are exemplary type distinctions, and additional cell types may be defined and utilized for subsequent grouping. In addition, the upper limit voltage and the lower limit voltage in [Table 2] may be adjusted in consideration of the yield of the standard distribution. That is, when the upper limit voltage is increased and the lower limit voltage is lowered, the cell end yield increases, but the yield in the second QC of the cell block (mono block) described below may decrease. Therefore, in a preferred embodiment of the present invention, a direction is proposed to increase the yield of a cell block unit by reducing the cell unit yield and reducing the cell-to-cell deviation.

[0135] The meaning of each of the above-mentioned inspection criteria can be explained as follows.

[0136] First, 1 st If the CC charge (S610) termination voltage falls below the lower limit, it can be seen as a case where the SOC is not met because the capacity is increased and the applied power is the same due to over-injection of electrolyte. It can also be a case where an excessive self-discharge rate is shown due to small internal resistance.

[0137] Conversely, 1 st If the CC charge (S610) termination voltage exceeds the upper limit, it can be seen as a case where SOC is exceeded (=overcharge) due to non-injection of electrolyte, the capacity is reduced, and the applied power is the same. It can also be a case where the electrochemical reaction efficiency within the cell is low due to large internal resistance.

[0138] In addition, if the upper limit of the OCV drop is exceeded, it may be due to a high self-discharge rate caused by poor separator bonding, poor separator bonding, or electrolyte crossover.

[0139]

[0140] Next, the second CC charge (S620) described above is a high-speed charge, so there is a possibility that an ionic imbalance of the electrolyte may have occurred. In particular, since the first CC charge (S610) is a high-speed charge in a non-separated electrolyte state, it is desirable to perform electrolyte stabilization.

[0141] Electrolyte stabilization can be achieved by methods such as maintaining a constant potential difference (CV (Constant Voltage) charging) and ultra-low-speed charging / discharging (CC charging / discharging).

[0142] The important point in this step is that it can be seen as a process of waiting for the ions to become equal over time, and this can be seen as a process similar to the Martian process of LIB, but there is a difference in that the time is much shorter at 6 hours as shown in [Table 1] above.

[0143] In this embodiment, 32 cells are connected in series for the first QC, so applying CV may overload some normal cells depending on the presence or absence of defective cells. Furthermore, as illustrated in Figure 6, since the SOC is already sufficiently high, stabilization through additional ultra-low-rate discharge may be ineffective.

[0144] Therefore, in a preferred embodiment of the present invention, it is proposed to configure the second CC charge (S620) as an ultra-low CC charge to achieve stabilization. That is, in the above description, the second criterion is determined in consideration of electrolyte stabilization, and it is proposed to apply 0.034C in a VIB where 32 cells are stacked as shown in [Table 1]. Through this, it is possible to resolve the ionic imbalance, pursue additional separation of the unseparated electrolyte, and thereby achieve a high SoC, making it easy to confirm self-discharge in the subsequent idle period (S630). However, the above-described numerical values ​​are exemplary values ​​that may be determined differently depending on the applied equipment, time, and statistics, and different values ​​may be applied depending on the applied equipment, time, and statistics.

[0145] Next, at the start of the aforementioned idle period (S630), a defective cell can be detected through the voltage of each cell.

[0146] The voltage range at the start of the idle period (S630) can be set as follows:

[0147] REST lower limit defective voltageREST upper limit defective voltageExample 1 1.430V or less 1.480V or moreExample 2 1.447V or less 1.460V or more Reason for defect CE low defect, high capacity defectLow capacity defect

[0148] Specifically, in the above [Table 3], the first embodiment presents a wider range than the second embodiment, and although the second embodiment can be used as the most optimal standard, this may vary depending on the characteristics of the battery (e.g., capacity (Ah)) as well as the conditions of charge and discharge (e.g., charging current of the first CC and / or the second CC), and thus is not necessarily limited to the ranges of the first embodiment and the second embodiment. As shown in the above [Table 1], when the starting voltage of the idle period (S630) is lower than or equal to the reference voltage, there may be a problem of CE degradation and / or high cell capacity, and when the starting voltage of the idle period (S630) is higher than or equal to the reference voltage, there may be a problem of low cell capacity.

[0149] Meanwhile, the above-described idle period (S630) can be viewed as a period for observing the self-discharge characteristics of stacked cells through a long idle period.

[0150] In [Table 1], which assumes a VIB with 32 cells stacked, the time is assumed to be 12 hours (the third criterion). Here, the third criterion can be set to the maximized time interval considering the aqueous battery manufacturing cycle. The example in [Table 1] shows that the maximized time interval considering the VIB manufacturing cycle is 12 hours. In other words, a longer time interval corresponding to the third criterion is advantageous, because the self-discharge characteristics become more clearly evident the longer it is observed.

[0151] When self-discharge is high, it usually corresponds to low current efficiency and high voltage efficiency. Since self-discharge is affected by the state of the separator (membrane), it can be estimated by the relationship (high membrane permeability) == (electrolyte mixing) == (low current efficiency), and conversely, (high membrane permeability) == (good ion movement) == (high voltage efficiency).

[0152] In one preferred embodiment of the present invention, a current efficiency of 99.5% or more is targeted, and QC can be performed by setting an upper limit of voltage change during the idle period (S630). That is, during the idle period (S630), cells that do not self-discharge exceeding the upper limit of voltage change among a plurality of cells can be selected as cells having a quality higher than the predetermined standard.

[0153] Next, in the above description, the discharge (S640) can be viewed as a procedure performed to proceed with cell-by-cell disassembly after discharging to a low SoC (e.g., 1.2 V) state, since the high SoC state is unstable in terms of pressure, operator safety, etc. In particular, multiple cells are subsequently disassembled and reassembled cell-by-cell, and care must be taken in handling them (short circuit, etc.) because the current collector is directly exposed and then reassembled.

[0154] Therefore, in the above-described embodiment, the fourth criterion, which is the criterion of SoC at the time of discharge (S640), can be determined by considering cell-by-cell disassembly for re-stacking, and can be shown to be determined as 1.2 V in the example of [Table 1].

[0155] Additionally, at high SoCs, the electrolyte volume increases slightly, and some gas may form inside. This can cause the cell to experience momentary stress when releasing the compression force, potentially damaging it. Therefore, it is safer to discharge quickly and proceed with subsequent operations.

[0156]

[0157] FIG. 7 is a drawing for explaining a quality control circuit device for performing cell quality inspection according to one embodiment of the present invention.

[0158] First, the circuit device illustrated in FIG. 7 may include a power supply (710) in which a + electrode is connected to a first test electrode (750) of a first cell among N cells connected in series, and a - electrode is connected to a second test electrode (760) of an Nth cell. In addition, the circuit device according to the present embodiment may include a relay (720) configured to disconnect the power supply (710) when the idle period described above with respect to FIG. 6 is applied.

[0159] In addition, the circuit device according to the present embodiment may include a timer (730) that is connected to the power supply (710) and the relay (720) to perform control according to time, and a BMS (Battery Management System; 740) that performs voltage logging according to the time of the timer (730).

[0160] At this time, the power supply (710) may be configured to change the current value when switching between the first CC charge that performs high-speed charging with a current higher than a first reference to the N cells and the second CC charge that performs low-speed charging with a current lower than a second reference after the first CC charge.

[0161] That is, the power supply (710) can be configured to sequentially apply the first CC charging (S610), the second CC charging (S620), the application of the idle period (S630) through the relay (720), and the discharging (S640) under the control of the BMS (740) described above with respect to FIG. 6, according to the time of the timer (730).

[0162] As illustrated in FIG. 7, the BMS (740) may include a channel corresponding to each of the N cells, and for example, when 32 cells are stacked, a BMS (740) with 32 channels may be utilized. In addition, the BMS (740) may perform a role of controlling so that the discharge is performed to a specific voltage (e.g., 1.2 V) after the application of the idle period.

[0163] In addition, the BMS (740) can assist in selecting cells that do not meet the criteria of lower voltage limit, upper voltage limit, or OCV upper limit exceeding as shown in [Table 2] among a plurality of cells after performing the first CC charge, as cells having a quality higher than a predetermined standard.

[0164]

[0165] Factors affecting the first QC (cell QC) described above with reference to FIGS. 6 and 7 include the following factors.

[0166] First, lower temperatures can increase cell voltage, while higher temperatures can decrease cell voltage. Accordingly, one embodiment of the present invention proposes setting the temperature management standard for the manufacturing line to 23 ± 1 degrees Celsius.

[0167] Additionally, the lower the resistance of the inspection electrode (e.g., 3T aluminum) (e.g., electrodes with low usage frequency and / or well-surfaced electrodes), the more the voltage tends to decrease. Accordingly, in one embodiment of the present invention, it is proposed to perform the first QC described above based on a certain resistance management standard.

[0168]

[0169] FIG. 8 is a diagram for explaining the concept of performing re-stacking using cells that have passed QC criteria according to one embodiment of the present invention.

[0170] That is, by applying the first QC described above in a stacked state of the multiple cells illustrated in FIG. 8, cells (810) exhibiting a quality higher than a predetermined standard can be selected. In order to perform re-stacking using these cells (810), it may be required to first disassemble the inspection stacking cells as described above.

[0171] A re-stacked cell block (820) using cells (810) that meet the QC criteria can be connected to each cell by a bus bar (830), and can correspond to a mono block (820) of 1.2 to 1.5 V and 110 A in the case of VIB.

[0172] FIG. 9 and FIG. 10 are drawings for explaining the concept of performing a second QC according to one embodiment of the present invention.

[0173] First, referring to FIG. 9, in the embodiment illustrated in FIG. 9, cell stacking is performed (S410), stacked cells are compressed (S420), an electrode is injected into the compressed cells (S430), a first QC corresponding to cell QC is performed (S440), a cell that has passed QC is selected (S450), and then re-stacking (S460) is performed as described above in FIG. 8, according to the embodiment described above with respect to FIG. 4.

[0174] Figure 9 illustrates the concept of performing a second QC (cell block QC; S700) on additionally re-stacked cells.

[0175] While the first QC uses a separate circuit device as described above with reference to FIG. 7, the second QC proposes to perform charging and discharging on the re-stacking cell block a predetermined number of times by using a general-purpose charger / discharger. Specifically, the cycle can proceed in the order of CC charge / discharge n times -> CCCV charge / discharge n times -> CCCV charge, where the CC charge / discharge is cycled rapidly, and the CCCV charge / discharge can be performed according to a group standard (e.g., in the case of VIB, SPS-C KBIA-10804-01-7563 of the Korea Battery Industry Association, enacted on May 22, 2023).

[0176] Additionally, it is desirable to conclude the final stage of the second QC (cell block QC) with a buffer. This can have the effect of checking for leakage during cell block storage and observing self-discharge through voltage measurement after long-term storage.

[0177] In the above-described second QC (S700), a single product may be referred to as a single cell or cell block, and in the case of VIB, as a monoblock.

[0178] Specifically, referring to FIG. 10, the second QC (S700) may include a cell stabilization step (710) including completely discharging undischarged cells in the first QC, a cell block internal resistance measurement step (S720) performing charging and discharging through high current, a step (S730) inducing complete discharge through discharging through low current, a step (S740) measuring the charging current amount through charging and discharging according to a standard cycle after the complete discharge (S730), and a step (S750) of completely charging the cell block.

[0179] FIG. 11 is a drawing for explaining each step of the second QC according to one embodiment of the present invention.

[0180] First, the cell stabilization step (S710) is performed to completely discharge the undischarged cell in the first QC as described above. To this end, the cell is discharged until it reaches 1.12 V, and then charging and discharging are repeated several times in a CC manner to achieve cell stabilization. Fig. 11 illustrates an example of repeating such charging and discharging for 4 cycles, but the number of repetitions need not be limited thereto.

[0181] The example of Fig. 11 illustrates an example in which the procedures indicated by ① - ④ are additionally performed between the cell stabilization step (S710) and the cell internal resistance measurement step (S720). These steps are procedures for performing charging (① - ②) and discharging (③-④) in a CC manner, and although they are not essential procedures, they may be additionally performed from the perspective of recording for future cause analysis. Preferably, the IR drop is measured using the rest period between procedures ① and ②, and the IR rise is measured using the rest period between procedures ③ and ④, which can be utilized for cause analysis of subsequent step measurements.

[0182] Next, the cell block internal resistance measurement step (S720) performs high-speed charging and discharging in the CC method, and can process it as a defect if it reaches a certain voltage (1.6 V in the case of VIB) before the completion of a set time during high-speed charging. In addition, through this step (S720), it can also be processed as a defect if the CE (Coulomb Efficiency) is less than 99% or the CE is more than 100%. Specifically, if the CE is less than 99%, it can be viewed as a case of membrane abnormality, and if the CE is more than 100%, it can be viewed as a case of abnormality in the discharge of the previous cycle. This cell block internal resistance measurement step (S720) has the characteristic of being able to classify even if the chargeable capacity is small.

[0183] Next, the step (S730) of inducing complete discharge by discharging through low current can be viewed as a step of performing additional discharge at 0.5 C, as the standard cycle is stipulated as 0.5 C in the VIB group standard described above. At this time, if discharging is performed at a low current, a deeper discharge can be performed.

[0184] Next, the step (S740) of measuring the charging current through charging and discharging according to the standard cycle may include a CCCV charging step and a CC discharging step. Considering that the charging current corresponds to the energy capacity, energy efficiency can also be measured at this step. Through this, whether the CCCV capacity is defective or the CC capacity is defective can be confirmed.

[0185] Finally, the fully charging step (S750) has the advantage of being able to check for leakage and self-discharge rate through storage as described above.

[0186]

[0187] The detailed description of the preferred embodiments of the present invention disclosed above has been provided to enable those skilled in the art to implement and practice the present invention. While the above description has been made with reference to preferred embodiments of the present invention, those skilled in the art will appreciate that various modifications and variations can be made to the present invention without departing from the scope of the present invention. For example, those skilled in the art can utilize the individual components described in the above-described embodiments in combination with each other.

[0188] Accordingly, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0189] The cell quality inspection method and device therefor of an aqueous battery according to the embodiments of the present invention as described above, and the method and system for manufacturing a cell block based thereon, can be utilized for quality inspection / manufacturing of various aqueous batteries as well as VRFB and VIB.

Claims

1. A method for manufacturing a cell block of an aqueous battery using a liquid electrode, Stacking cells containing multiple layers; Injecting the liquid electrode into each of the plurality of cells in which the above cells are stacked; With the above multiple cells electrically connected, power is applied to perform the first quality control; Select cells having a quality higher than a predetermined standard according to the above first quality control results; and A method for manufacturing a cell block of an aqueous battery, comprising re-stacking the selected cells to manufacture the cell block.

2. In paragraph 1, In the above first quality control, A method for manufacturing a cell block of an aqueous battery, wherein the above-mentioned plurality of cells are connected in series and a constant current (CC) is applied.

3. In paragraph 2, The above first quality control is, Performing a first CC charge to fast-charge the plurality of cells with a current higher than a first reference value; After the above first CC charge, a second CC charge is performed by performing low-speed charging with a current lower than the second reference; Applying a rest period that induces self-discharge for a period of time longer than the third standard after the above second CC charge; and A method for manufacturing a cell block of an aqueous battery, comprising discharging the plurality of cells to a SoC (State of Charge) below a fourth criterion after the above-mentioned idle period.

4. In paragraph 3, A method for manufacturing a cell block of an aqueous battery, wherein if the above-mentioned idle period start voltage is 1.430 V or less or 1.480 V or more, the cell is not selected as a cell having a quality higher than the above-mentioned standard.

5. In paragraph 3, A method for manufacturing a cell block of an aqueous battery, wherein if the above-mentioned idle period start voltage is 1.447 V or less or 1.460 V or more, the cell is not selected as a cell having a quality higher than the above-mentioned standard.

6. In paragraph 3, A method for manufacturing a cell block of an aqueous battery, wherein, after performing the first CC charge, cells among the plurality of cells that do not meet the criteria of falling below the lower limit voltage, exceeding the upper limit voltage, or exceeding the OCV upper limit are selected as cells having a quality higher than the predetermined criteria.

7. In paragraph 3, A method for manufacturing a cell block of an aqueous battery, wherein cells that have not undergone self-discharge exceeding an upper limit of voltage change among the plurality of cells during the above-described idle period are selected as cells having a quality higher than the predetermined standard.

8. In paragraph 1, Re-stacking the above cells is: After performing the above first quality control, the plurality of cells are disassembled into cell units; Among cells having a quality higher than the above-mentioned standard, the types are distinguished based on at least one of the charging performance and the discharging performance; and A method for manufacturing a cell block of an aqueous battery, comprising grouping the cells according to the above-described types and performing re-stacking.

9. In paragraph 3, A method for manufacturing a cell block of an aqueous battery, wherein the fourth criterion is determined by considering cell unit disassembly for the re-stacking.

10. In paragraph 3, The above first quality control is, A power supply configured to change a current value when switching between the first CC charge and the second CC charge; A relay configured to disconnect the power supply when the above-mentioned idle period is applied; A timer connected to the above power supply and the above relay, which performs time-dependent control; and A BMS (Battery Management System) that controls the discharge to be performed to a specific voltage after voltage logging and application of the rest period according to the time of the above timer. A method for manufacturing cell blocks of an aqueous battery, the method being performed through a quality control circuit.

11. In paragraph 1, It additionally includes performing a second quality control on the manufactured cell block, A method for manufacturing a cell block of an aqueous battery, wherein the second quality control is performed by repeatedly charging and discharging the cell block a predetermined number of times.

12. In paragraph 11, The above secondary quality control is, A cell stabilization step including completely discharging the undischarged cells in the above first quality control; Step of measuring the internal resistance of a cell block while charging and discharging through high current; A step of inducing complete discharge by discharging through low current; A step of measuring the charging current by charging and discharging according to a standard cycle after the above complete discharge; and A method for manufacturing a cell block of an aqueous battery, comprising the step of fully charging the cell block.

13. In paragraph 11, A method for manufacturing cell blocks of an aqueous battery, wherein the above second quality control is performed through a universal charger / discharger.

14. In paragraph 1, Stacking the above cells is: A method for manufacturing a cell block of an aqueous battery, comprising: including an inspection electrode outside the above-mentioned plurality of layers.

15. In paragraph 1, Injecting the above liquid electrode, A method for manufacturing a cell block of an aqueous battery, which is performed after compressing the above-mentioned stacked plurality of cells.

16. In a system for manufacturing cell blocks based on cell quality inspection of an aqueous battery utilizing a liquid electrode, A cell stacking unit configured to stack cells including multiple layers; A liquid electrode injector that injects the liquid electrode into each of the plurality of cells stacked in the cell stacking section; and A quality control circuit device for performing cell quality inspection by applying power while the plurality of cells are electrically connected, The above cell stacking part, A cell block manufacturing system for an aqueous battery, further configured to select cells having a quality higher than a predetermined standard according to the cell quality inspection result of the quality control circuit device, and to manufacture the cell block by re-stacking the selected cells.

17. In paragraph 16, The above cell stacking part, A cell block manufacturing system for an aqueous battery, which performs cell stacking by including an inspection electrode on the outer side of the plurality of layers.

18. In paragraph 17, The above multiple layers are, A separator comprising: a solid electrode pair positioned at both ends of the outer surface of the separator; and a current collector pair positioned on the outer surface of each of the solid electrode pairs. A system for manufacturing cell blocks of an aqueous battery, wherein the above-mentioned inspection electrodes are located on the outer side of each of the above-mentioned current collector pairs.

19. In paragraph 18, It additionally includes a compressor that compresses a plurality of cells stacked in the above cell stacking section, The above liquid electrode injector is a cell block manufacturing system of an aqueous battery, which injects the liquid electrode into each of the cells compressed by the compressor.

20. In paragraph 19, A frame having a predetermined thickness is placed on the left and right sides of the above solid electrode pair. A system for manufacturing cell blocks of an aqueous battery, wherein the above-mentioned predetermined thickness is determined according to the degree to which the compressor compresses the plurality of cells.

21. In paragraph 20, A system for manufacturing cell blocks of an aqueous battery, wherein the horizontal area of ​​the frame is set such that the combined horizontal area of ​​the frame and the solid electrode corresponds to the horizontal area of ​​the current collector.

22. In paragraph 18, A system for manufacturing a cell block of an aqueous battery, wherein the above-described inspection electrode has a thickness equal to or greater than a first thickness determined to prevent deformation of the current collector due to injection of the liquid electrode.

23. In paragraph 22, The above inspection electrode is a cell block manufacturing system of an aqueous battery, which is composed of 3T aluminum.

24. In paragraph 16, The above water-based battery includes a VIB (Vanadium Ion Battery), The above cell block is a cell block manufacturing system of an aqueous battery corresponding to the monoblock of the VIB.

25. A method for performing cell quality inspection of an aqueous battery using a liquid electrode, Performing a first CC (Constant Current) charge to fast-charge a plurality of stacked cells with a current higher than a first reference value; After the above first CC charge, a second CC charge is performed by performing low-speed charging with a current lower than the second reference; Applying a rest period that induces self-discharge for a period of time longer than the third standard after the above second CC charge; and A method for performing cell quality inspection of an aqueous battery, comprising performing a discharge to discharge the plurality of cells to a State of Charge (SoC) below a fourth criterion after the above-mentioned idle period.

26. In paragraph 25, The above first criterion is determined by taking into account the limits of the quality control circuit device, A method for performing cell quality inspection of an aqueous battery, wherein the second criterion is determined by taking electrolyte stabilization into consideration.

27. In paragraph 25, The above third criterion is set to the maximum time interval considering the above water-based battery manufacturing cycle, The fourth criterion is a method for performing cell quality inspection of an aqueous battery, which is determined by considering cell unit disassembly for re-stacking.

28. In paragraph 25, A method for performing cell quality inspection of an aqueous battery, wherein if the above-mentioned idle period start voltage is 1.430 V or less or 1.480 V or more, the cell is not selected as a cell having a quality higher than a predetermined standard.

29. In paragraph 25, A method for performing cell quality inspection of an aqueous battery, wherein if the above-mentioned idle period start voltage is 1.447 V or less or 1.460 V or more, the cell is not selected as a cell having a quality higher than a predetermined standard.

30. In paragraph 25, A method for performing cell quality inspection of an aqueous battery, wherein, after performing the first CC charge, cells among the plurality of cells that do not meet the criteria of falling below a lower voltage limit, exceeding an upper voltage limit, or exceeding an OCV upper limit are selected as cells having a quality higher than a predetermined standard.

31. In paragraph 30, A method for performing cell quality inspection of an aqueous battery, wherein the criteria for falling short of the lower voltage limit and exceeding the upper voltage limit are set differently depending on whether the cell is a first type cell or a second type cell.

32. A quality control circuit device for performing cell quality inspection of an aqueous battery utilizing a liquid electrode, A power supply in which a + electrode is connected to a first test electrode of a first cell among N cells connected in series, and a - electrode is connected to a second test electrode of an Nth cell; A relay configured to disconnect said power supply when a rest period is applied; A timer connected to the above power supply and the above relay, which performs time-dependent control; and Includes a BMS (Battery Management System) that performs voltage logging according to the time of the above timer, The above power supply, A device for performing cell quality inspection of an aqueous battery, wherein the current value is configured to change when switching between a first CC (Constant Current) charge that performs fast charging with a current higher than a first reference current on the N cells and a second CC charge that performs slow charging with a current lower than a second reference current after the first CC charge.

33. In paragraph 32, The above BMS, Contains a channel corresponding to each of the above N cells, A device for performing cell quality inspection of an aqueous battery, configured to control discharge to be performed to a specific voltage after application of the above-mentioned rest period.

34. In paragraph 33, The above power supply, A device for performing cell quality inspection of an aqueous battery, configured such that the first CC charging, the second CC charging, the application of the idle period through the relay, and the discharging by the control of the BMS are sequentially applied according to the time of the timer.

35. In paragraph 34, The above BMS, A device for performing cell quality inspection of an aqueous battery, which selects cells among the N cells that do not meet the criteria of lower voltage limit, upper voltage limit, or OCV upper limit after performing the first CC charge as cells having a quality higher than a predetermined standard.

36. In paragraph 35, A device for performing cell quality inspection of an aqueous battery, wherein the criteria for falling short of the lower limit voltage and exceeding the upper limit voltage are set differently depending on whether the cell is a first type cell or a second type cell.

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