Manufacturing apparatus and method for manufacturing electrochemical cells

Abstract

To ensure the internal pressure by reducing clogging of a gas flow path when depressurizing an exterior body.SOLUTION: A manufacturing device includes a chamber, a pressure reducing device, and a return line. The pressure reducing device is configured to reduce the pressure in the chamber. The return line includes a first opening, a conduit, and a second opening. The first opening and the second opening are independently opened into the chamber. The first opening is configured to be connected to an exterior body. The conduit connects the first opening and the second opening. The conduit extends in such a manner that, when the pressure in the chamber is reduced, the conduit once draws out the gas in the exterior body to the outside of the chamber, and then returns the drawn out gas into the chamber.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a manufacturing apparatus and a method for manufacturing an electrochemical cell. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2018-106850 (Patent Document 1) discloses a liquid injection device and a liquid injection method that can improve the production efficiency of power storage modules. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-106850 Summary of the Invention [Problem to be solved by the invention]

[0004] In general, electrochemical cells (hereinafter may be abbreviated as "cells") are manufactured by housing, for example, a power generating element and an electrolyte in an exterior body. When the cell is in use, gas may be generated inside the exterior body due to, for example, deterioration of the electrolyte. The gas generation may increase the internal pressure of the exterior body. In consideration of future gas generation, it is desirable to reduce the gas inside the exterior body as much as possible during the manufacturing stage. Therefore, the pressure inside the exterior body may be reduced. For example, the pressure inside the exterior body is reduced using a vacuum pump or the like. After the pressure inside the exterior body (degree of reduction in pressure) reaches a target value, the exterior body is sealed.

[0005] An exterior body with low rigidity may be used. For example, a sheet-like exterior body such as a metal foil laminate film may be used. If the exterior body has low rigidity, when the pressure inside the exterior body is reduced, the exterior body may be pushed by external pressure and deformed. The deformation of the exterior body may cause the gas flow path to become blocked. If the gas flow path is blocked, even if the pressure gauge indicates the target value, the interior of the exterior body may not have reached the desired degree of reduced pressure.

[0006] An object of the present disclosure is to ensure the internal pressure by reducing blockage of the gas flow path when reducing the pressure inside the exterior body. [Means for solving the problem]

[0007] A manufacturing apparatus for manufacturing an electrochemical cell with a reduced pressure inside an exterior body, a chamber; a pressure reducing device; Return piping and Including, the pressure reducing device is configured to reduce pressure inside the chamber; the return pipe includes a first opening, a conduit, and a second opening; the first opening and the second opening each independently open into the chamber, the first opening is configured to be connected to the exterior body; the conduit connects the first opening and the second opening, the conduit extends so as to once draw the gas within the exterior body to the outside of the chamber when the pressure inside the chamber is reduced, and then return the drawn gas into the chamber. Manufacturing equipment.

[0008] Hereinafter, an embodiment of the present disclosure (hereinafter may be abbreviated as "the present embodiment") and an example of the present disclosure (hereinafter may be abbreviated as "the present example") will be described. However, the present embodiment and the example do not limit the technical scope of the present disclosure. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a first conceptual diagram of the reduced pressure state. [Figure 2] FIG. 2 is a second conceptual diagram of the reduced pressure state. [Figure 3] FIG. 3 is a conceptual diagram showing an example of a cell module. [Figure 4] FIG. 4 is a conceptual diagram showing an example of a manufacturing apparatus according to this embodiment. [Figure 5]FIG. 5 is a schematic flowchart of a method for producing an electrochemical cell in this embodiment. [Figure 6] FIG. 6 is a schematic cross-sectional view of the first unit, the second unit, and the third unit in this embodiment. [Figure 7] FIG. 7 is a schematic cross-sectional view of a bipolar cell module according to this embodiment. [Figure 8] FIG. 8 is a schematic top view of the bipolar cell module of this embodiment. [Figure 9] FIG. 9 is a conceptual diagram showing a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Definitions of terms, etc.> In this specification, the terms "comprise," "include," "have," and variations thereof (e.g., "consisting of") are open-ended. Open-ended terms may or may not include additional elements in addition to the required elements. The term "consisting of" is closed-ended. However, even in closed-ended terms, additional elements that are normally incidental impurities or unrelated to the disclosed technology are not excluded. The term "consisting essentially of..." is semi-closed. Semi-closed terms allow for the addition of elements that do not substantially affect the basic and novel characteristics of the disclosed technology.

[0011] In this specification, expressions such as "may" and "can" are used in the permissive sense of "possibly" rather than the obligatory sense of "must."

[0012] In this specification, the order of execution of multiple steps, actions, operations, etc. included in various methods is not limited to the order described unless otherwise specified. For example, multiple steps may proceed simultaneously. For example, multiple steps may occur one after the other.

[0013] Geometric terms used in this specification (e.g., "parallel," "perpendicular," "orthogonal," etc.) should not be interpreted in a strict sense. For example, "parallel" may deviate slightly from the strict meaning of "parallel." Geometric terms used in this specification may include, for example, tolerances, errors, etc. in design, work, manufacturing, etc. The dimensional relationships in each drawing may not match the actual dimensional relationships. To facilitate understanding of the disclosed technology, the dimensional relationships (length, width, thickness, etc.) in each drawing may be changed. Furthermore, some configurations may be omitted.

[0014] As used herein, the term "electrochemical cell" refers to a single device that converts chemical energy into electrical energy. Electrochemical cells include primary batteries and secondary batteries. Electrochemical cells include lithium ion batteries and nickel-metal hydride batteries. Lithium ion batteries include liquid-state batteries and all-solid-state batteries. As used herein, the term "cell module" refers to an assembly of multiple electrochemical cells. The multiple electrochemical cells may or may not be electrically connected. The multiple electrochemical cells may form a series circuit or a parallel circuit.

[0015] In this specification, the "degree of reduced pressure" refers to the magnitude of the pressure of the gas remaining inside the exterior body after the pressure has been reduced. The degree of reduced pressure may also be referred to as the degree of vacuum.

[0016] <Outline of this embodiment> First, an outline of the present embodiment will be described. Note that the mechanism of action in this specification includes speculation. The mechanism of action does not limit the present embodiment.

[0017] 1. A manufacturing apparatus can manufacture an electrochemical cell with a reduced pressure inside an exterior body. The manufacturing apparatus includes a chamber, a pressure reducing device, and a return pipe. The pressure reducing device is configured to reduce the pressure inside the chamber. The return pipe includes a first opening, a conduit, and a second opening. The first opening and the second opening each independently open into the chamber. The first opening is configured to be connected to the exterior body. The conduit connects the first opening and the second opening. When the pressure inside the chamber is reduced, the conduit temporarily draws gas inside the exterior body to the outside of the chamber and then extends to return the drawn gas into the chamber.

[0018] FIG. 1 is a first conceptual diagram of the reduced pressure state. By discharging the gas inside the exterior body 210, the internal pressure P I However, external pressure P E That is, the inside of the exterior body 210 is in a negative pressure state relative to the surrounding atmosphere. E The gas flow path may be blocked by being crushed by the gas.

[0019] FIG. 2 is a second conceptual diagram of the reduced pressure state. The white arrows in FIG. 2 indicate the flow of gas. In the manufacturing apparatus of "1" above, gas inside the exterior body 210 can be discharged via the return pipe 140. By reducing the pressure inside the chamber 110, the pressure inside the chamber 110 (external pressure P E ) decreases. Pressure loss may occur in the return pipe 140. Therefore, the internal pressure P I is the external pressure P E That is, the inside of the exterior body 210 may be in a positive pressure state relative to the surrounding atmosphere (the atmosphere inside the chamber 110). By maintaining the positive pressure state during decompression, the internal space of the exterior body 210 may be increased to the external pressure P E In other words, it is thought that the gas flow path is less likely to be blocked.

[0020] 2. The manufacturing apparatus may include a plurality of return pipes, each of which independently includes a first opening, a conduit, and a second opening.

[0021] In the manufacturing equipment of "1" above, for example, a single cell can be manufactured. In the manufacturing equipment of "2" above, for example, a cell module can also be manufactured. The manufacturing equipment of "2" above is considered to be suitable for manufacturing a cell module.

[0022] FIG. 3 is a conceptual diagram showing an example of a cell module. The cell module 250 includes a partition 230. The partition 230 separates adjacent cells 200. If the gas flow path of an outer cell 200 is blocked due to deformation of the exterior body 210, the blockage can be detected by appearance. The white arrow in FIG. 3 indicates an example of the direction of deformation. For example, if the gas flow path of an inner cell 200 is blocked due to deformation of the partition 230, it is difficult to detect the blockage by appearance.

[0023] By connecting each cell to a separate return line, it is believed that each cell can be depressurized while maintaining a positive pressure in each cell, which is believed to reduce blockage of the gas flow path in the inner cells.

[0024] In the manufacturing apparatus of the above "2", the target of pressure reduction is one chamber, so that one pressure reduction device can simultaneously reduce the pressure of multiple cells.

[0025] 3. The manufacturing apparatus may further include a pressure gauge connected to the pipeline.

[0026] Pressure gauges may be used to check the degree of vacuum in each individual cell.

[0027] 4. The manufacturing apparatus may further include a flow meter connected to the pipeline.

[0028] For example, the total amount of gas discharged may be determined by integrating the measured values ​​of a flow meter. For example, the degree of pressure reduction of each cell may be confirmed from the total amount of gas discharged and the internal space (volume) of the exterior body.

[0029] 5. The manufacturing apparatus may further include a sealing device. The sealing device may be configured to seal the exterior body within the chamber.

[0030] 6. A method for producing an electrochemical cell includes the following steps (a) to (e): (a) Prepare the manufacturing equipment described above in "1." (b) The workpiece is prepared by housing the power generating element within the exterior body. (c) The workpiece is placed in the chamber. (d) Connecting the exterior body to the first opening. (e) By reducing the pressure inside the chamber, the pressure inside the exterior body is reduced via the return pipe.

[0031] The manufacturing device of "1" above can be used, for example, in the procedure of "6" above.

[0032] 7. In (a) above, for example, a manufacturing apparatus including a plurality of return pipes that are independent of each other may be prepared. In (b) above, a cell module including a plurality of electrochemical cells may be prepared as a workpiece. Each of the plurality of electrochemical cells includes an independent internal space. In (d) above, a separate return pipe may be connected to each of the plurality of internal spaces.

[0033] The manufacturing method of "7" above can be used to manufacture a cell module. The cell module can be either a bipolar type or a monopolar type. In a bipolar type, the electrode has two polarities. For example, the front side of the electrode is a positive electrode and the back side is a negative electrode. This electrode can also be called a bipolar electrode. In a monopolar type, the electrode has a single polarity. That is, the electrode is either a positive electrode or a negative electrode.

[0034] 8. In the above (a), for example, a manufacturing device including a pressure gauge may be prepared. In the above (e), the inside of the exterior body may be depressurized so that the reading of the pressure gauge becomes equal to or less than a reference value.

[0035] For example, the degree of reduced pressure may be confirmed by a pressure gauge.

[0036] 9. In the above (a), a manufacturing device including a flow meter may be prepared. In the above (e), after the pressure reduction is stopped, the inside of the exterior body may be reduced in pressure so that the integrated value of the measurement value of the flow meter becomes equal to or greater than a reference value.

[0037] For example, the degree of reduced pressure may be confirmed by a flow meter. For example, the degree of reduced pressure may be confirmed by using a pressure meter and a flow meter in combination.

[0038] 10. A liquid filling port may be formed in the exterior body. The electrolyte may be poured into the exterior body through the liquid filling port. In the above (d), the first opening of the return pipe may be connected to the liquid filling port.

[0039] For example, gas may be discharged from a liquid inlet of the exterior body.

[0040] 11. The exterior body may include at least one selected from the group consisting of metal foil and metal foil laminate film.

[0041] Metal foils and metal foil laminate films can have low rigidity. The manufacturing method "6" above is considered to be suitable for cases where the rigidity of the exterior body is low.

[0042] 12. In the above (b), a bipolar cell module may be prepared as the workpiece.

[0043] The manufacturing method "7" above is considered to be suitable for bipolar cell modules.

[0044] 13. The method for producing an electrochemical cell may further include: (f) (f) The outer casing is sealed under reduced pressure.

[0045] <Details of this embodiment> Next, the details of this embodiment will be described.

[0046] <Manufacturing equipment> FIG. 4 is a conceptual diagram showing an example of a manufacturing apparatus according to this embodiment. Hereinafter, the "manufacturing apparatus in this embodiment" may be abbreviated as "the present manufacturing apparatus." The present manufacturing apparatus 100 includes a chamber 110, a pressure reducing device 130, and a return pipe 140. The present manufacturing apparatus 100 may further include, for example, a sealing device 120, a pressure gauge 150, and a flow meter 160.

[0047] Chamber The chamber 110 can provide a stable sealed space in a reduced pressure state. The chamber 110 may be, for example, a metal container. The chamber 110 may include, for example, an exhaust port 111. The exhaust port 111 may be connected to a pressure reducing device 130. For example, a stage, a holder, etc. (not shown) may be provided inside the chamber 110. A workpiece 201 may be held on the stage, holder, etc.

[0048] <Sealing device> The sealing device 120 may be configured to seal the exterior body 210, for example, within the chamber 110. The sealing device 120 may be configured to seal the exterior body 210, for example, outside the chamber 110. The sealing device 120 may seal the exterior body 210 by any method. The sealing device 120 may include, for example, a heat welding device, an ultrasonic welding device, etc. The sealing device 120 may be disposed, for example, within the chamber 110. For example, a portion of the sealing device 120 may be disposed within the chamber 110. For example, a portion that actually performs sealing may be disposed within the chamber 110. The portion that performs sealing may include, for example, a press unit, a heat bar, a heat plate, an ultrasonic horn, an anvil, etc. The sealing device 120 may be disposed, for example, outside the chamber 110.

[0049] Decompression device The pressure reducing device 130 is configured to reduce the pressure inside the chamber 110. The pressure reducing device 130 may include, for example, a vacuum pump, a compressor, or the like.

[0050] <Return piping> The return pipe 140 may have sufficient strength to prevent deformation due to external pressure when the pressure is reduced. The return pipe 140 may be made of, for example, metal. The return pipe 140 includes a first opening 141, a pipe line 143, and a second opening 142. The first opening 141 and the second opening 142 each independently open into the chamber 110. The positions of the first opening 141 and the second opening 142 are arbitrary as long as they are not the same. The first opening 141 is configured to be connected to the exterior body 210. For example, a jig for connecting to the exterior body 210 may be attached to the first opening 141.

[0051] Pipe 143 connects first opening 141 and second opening 142. First opening 141 is disposed at one end of pipe 143. Second opening 142 is disposed at the other end of pipe 143. The white arrows in FIG. 4 indicate the flow of gas. Pipe 143 extends so as to draw gas from inside exterior body 210 to the outside of chamber 110 when the pressure inside chamber 110 is reduced, and then return the drawn gas to chamber 110. That is, when the pressure inside chamber 110 is reduced, gas inside exterior body 210 is sucked in through first opening 141. The sucked gas passes through pipe 143 and is released into chamber 110 through second opening 142. It is believed that pressure loss occurs inside pipe 143. Due to the pressure loss, the interior of exterior body 210 may become positive pressure relative to the atmosphere inside chamber 110. By reducing the pressure inside the exterior body 210 in a positive pressure state, blockage of the gas flow path inside the exterior body 210 can be reduced.

[0052] Pipe 143 may have an inner diameter of, for example, 1 to 10 mm, or may have an inner diameter of 2 to 6 mm. An appropriate pressure loss can occur at an inner diameter of 1 to 10 mm. The inner diameter of pipe 143 may be constant or may vary. Pressure loss may occur due to the change in the inner diameter. Pipe 143 may have, for example, multiple elbows. Pressure loss may occur at the elbows.

[0053] The manufacturing apparatus 100 may include a single return pipe 140. The manufacturing apparatus 100 may include multiple return pipes 140. FIG. 4 shows three return pipes 140 as an example. Each of the multiple return pipes 140 includes a first opening 141, a pipeline 143, and a second opening 142, independent of one another. The manufacturing apparatus 100 including multiple return pipes 140 enables the manufacture of a cell module 250. The number of return pipes 140 may correspond to the number of cells 200 included in the cell module 250.

[0054] Pressure gauge The manufacturing apparatus 100 may further include a pressure gauge 150. The pressure gauge 150 is connected to the pipe 143. A pressure gauge 150 having an appropriate pressure range can be selected depending on the desired degree of reduced pressure. The degree of reduced pressure inside the exterior body 210 can be confirmed from the reading of the pressure gauge 150. When the manufacturing apparatus 100 includes multiple return pipes 140, a pressure gauge 150 may be connected to each of the multiple return pipes 140.

[0055] 《Flowmeter》 The manufacturing apparatus 100 may further include a flow meter 160. The flow meter 160 is connected to the pipeline 143. A flow meter 160 having an appropriate flow range can be selected depending on the gas flow rate. The gas flow rate is measured by the flow meter 160. The integrated value of the measured values ​​is considered to be the total amount of gas discharged. The degree of pressure reduction inside the exterior body 210 can be confirmed from the total amount of gas discharged and the internal space inside the exterior body 210. If the manufacturing apparatus 100 includes multiple return pipes 140, a flow meter 160 may be connected to each of the multiple return pipes 140.

[0056] <Electrochemical cell manufacturing method> FIG. 5 is a schematic flowchart of a method for producing an electrochemical cell in this embodiment. Hereinafter, the "method of manufacturing an electrochemical cell according to this embodiment" may be abbreviated as "the present manufacturing method." The present manufacturing method includes "(a) preparation of manufacturing equipment," "(b) preparation of workpiece," "(c) placement of workpiece," "(d) connection to return piping," and "(e) pressure reduction." The present manufacturing method may further include, for example, "(f) sealing." Note that the order of description in FIG. 5 is merely formal. For example, "(a) preparation of manufacturing equipment" and "(b) preparation of workpiece" may be performed in sequence.

[0057] (a) Preparation of manufacturing equipment The present manufacturing method includes preparing the present manufacturing apparatus 100. Details of the present manufacturing apparatus 100 are as described above.

[0058] (b) Preparation for the work This manufacturing method includes preparing a workpiece 201 by housing a power generating element 220 in an exterior housing 210. The workpiece 201 is, so to speak, a "pre-sealed cell." For example, a bipolar cell module may be prepared as the workpiece 201. The bipolar cell module includes a plurality of cells. The bipolar cell module may include, for example, 1 to 100 cells, 10 to 50 cells, or 20 to 40 cells. Here, the "bipolar cell module" will be simply referred to as a "cell module."

[0059] 6 is a schematic cross-sectional view of the first unit, the second unit, and the third unit in this embodiment. The first unit 251, the second unit 252, and the third unit 253 can form a cell module 250. The first unit 251 and the third unit 253 are arranged at both ends in the stacking direction (Z-axis direction). The second unit 252 is stacked between the first unit 251 and the third unit 253.

[0060] The exterior body 210 is sheet-shaped. The exterior body 210 may function as a current collector. The exterior body 210 may include at least one material selected from the group consisting of metal foil and metal foil laminate film. The metal foil laminate film may be formed by coating a metal foil with a resin layer. The resin layer may include, for example, polypropylene (PP), polyethylene terephthalate (PET), or the like. The metal foil may include, for example, at least one material selected from the group consisting of aluminum (Al) foil, stainless steel (SUS) foil, nickel (Ni) foil, titanium (Ti) foil, and copper (Cu) foil. For example, the metal foil may be plated. For example, the SUS foil may be Ni-plated. The exterior body 210 may include, for example, at least one material selected from the group consisting of Al foil and Al foil laminate film.

[0061] A positive electrode layer 10 is formed on one surface of one exterior body 210, thereby preparing a first unit 251. The positive electrode layer 10 includes a positive electrode active material. The positive electrode active material may include, for example, lithium nickel cobalt manganese oxide, lithium iron phosphate, or the like. The positive electrode layer 10 may further include, for example, a conductive material, a binder, a solid electrolyte, or the like.

[0062] The negative electrode layer 20 is formed on one surface of the other exterior body 210. The negative electrode layer 20 includes a negative electrode active material. The negative electrode active material may include, for example, graphite, silicon, silicon oxide, etc. The negative electrode layer 20 may further include, for example, a conductive material, a binder, a solid electrolyte, etc. A separator 30 is attached to the surface of the negative electrode layer 20 to prepare a third unit 253. The separator 30 may include, for example, a porous film. The porous film may include, for example, a polyolefin, etc. The separator 30 may include, for example, a solid electrolyte layer.

[0063] The partition 230 is sheet-shaped. The partition 230 may be made of the same material as the exterior body 210, or may be made of a different material from the exterior body 210. The partition 230 may function as a current collector. The partition 230 may include, for example, a metal foil. The partition 230 may include, for example, an Al foil. A positive electrode layer 10 is formed on one side of the partition 230. A negative electrode layer 20 is formed on the side opposite to the side on which the positive electrode layer 10 is formed. A bipolar electrode is formed by integrating the positive electrode layer 10, the partition 230, and the negative electrode layer 20. In the bipolar electrode, a separator 30 is attached to the surface of the negative electrode layer 20, thereby preparing a second unit 252.

[0064] FIG. 7 is a schematic cross-sectional view of a bipolar cell module according to this embodiment. A cell module 250 is formed by stacking a first unit 251, a second unit 252, ..., a second unit 252, and a third unit 253. A set of a positive electrode layer 10, a separator 30, and a negative electrode layer 20 forms a power generating element 220. A cell 200 is formed by sandwiching the power generating element 220 between two partitions 230. At both ends in the stacking direction, the power generating element 220 is sandwiched between the partitions 230 and the exterior body 210 to form the cell 200. Each cell 200 independently includes an internal space.

[0065] The exterior body 210 includes a sealing material 240. For example, the sealing material 240 may be arranged so as to fill the periphery of the power generating element 220. The sealing material 240 may include, for example, a thermoplastic resin (such as PP). A liquid inlet 241 may be formed in a part of the sealing material 240. That is, the liquid inlet 241 may be formed in the exterior body 210. The liquid inlet 241 is a hole that can serve as a liquid flow path and a gas flow path. The electrolyte may be injected into each cell 200 through the liquid inlet 241. That is, the electrolyte may be injected into the exterior body 210 through the liquid inlet 241.

[0066] FIG. 8 is a schematic top view of the bipolar cell module of this embodiment. The cell module 250 may have any planar shape. The planar shape of the cell module 250 may be, for example, rectangular. The sealant 240 may be disposed so as to surround the periphery of the exterior body 210. Note that the cross-sectional view taken along line AA in FIG. 8 is FIG. 7.

[0067] For example, a monopolar cell module may be prepared as the workpiece 201. For example, the partition 230 may be composed of a plurality of sheet-like members. In this case, the positive electrode layer 10 is formed on one side of one of the sheet-like members of the partition 230. The negative electrode layer 20 is formed on one side of the other sheet-like member of the partition 230. A monopolar cell is constructed by overlapping one sheet-like member with the other sheet-like member so that the positive electrode layer 10 and the negative electrode layer 20 face each other. Between adjacent monopolar cells, the surface of one sheet-like member included in one cell opposite the surface on which the positive electrode layer 10 is formed is overlapped with the surface of the other sheet-like member included in the other cell opposite the surface on which the negative electrode layer 20 is formed, thereby constructing a monopolar cell module.

[0068] (c) Work placement This manufacturing method includes placing the workpiece 201 in the chamber 110. For example, the workpiece 201 after the liquid injection can be placed in the chamber 110 (see FIG. 4).

[0069] (d) Connection to return pipe This manufacturing method includes connecting the exterior body 210 and the first opening 141 (return pipe 140) (see FIG. 4). For example, the liquid inlet 241 may be connected to the first opening 141. In the case of the cell module 250, a separate return pipe 140 may be connected to the liquid inlet 241 of each cell 200. A gas exhaust port (not shown) may be provided in the exterior body 210 in addition to the liquid inlet 241. The gas exhaust port may function as a gas flow path.

[0070] (e) Decompression This manufacturing method includes reducing the pressure inside the chamber 110, thereby reducing the pressure inside the exterior body 210 via the return pipe 140 (see FIG. 4). The pressure inside the chamber 110 can be reduced by the pressure reducing device 130. Pressure loss can occur inside the return pipe 140.

[0071] Completion of the decompression may be determined, for example, by the reading of pressure gauge 150. For example, it may be determined that the target degree of decompression has been reached when the reading of pressure gauge 150 is equal to or less than a reference value. In other words, the pressure inside exterior body 210 may be reduced so that the reading of pressure gauge 150 becomes equal to or less than the reference value.

[0072] Completion of the decompression may be determined, for example, by the flow meter 160. For example, after the decompression device 130 is stopped, it may be determined that the target degree of decompression has been reached when the integrated value of the measurement values ​​of the flow meter 160 (total amount of discharged gas) is equal to or greater than a reference value. If the target degree of decompression has not been reached, the decompression device 130 may be started again.

[0073] The reference values ​​for pressure and flow rate can be set appropriately depending on the desired degree of reduced pressure, the shape of the conduit 143, etc. The desired degree of reduced pressure may be, for example, 5 to 50 kPa.

[0074] (f) Seal This manufacturing method may include sealing the exterior body 210 under reduced pressure. This seals the cell module 250. The cell module 250 includes a plurality of cells 200. For example, the liquid inlet 241 may be sealed by a sealing device 120 inside the chamber 110. For example, the sealing material 240 is melted and solidified by heat pressing. The liquid inlet 241 may be closed by the sealing material 240 (see FIG. 7). For example, the liquid inlet 241 may be closed outside the chamber 110. [Example]

[0075] <Experiment> In this experiment, a cell module 250 was prepared as the workpiece 201. The cell module 250 was of a bipolar type. The cell module 250 included five cells 200.

[0076] Example In the examples, the present manufacturing apparatus 100 was used (see FIG. 4). Separate return pipes 140 were connected to five cells 200, respectively. By reducing the pressure inside the chamber 110, the pressure inside the exterior body 210 was reduced via the return pipes 140. When the target reduced pressure was reached, the exterior body 210 was sealed. Whether the target reduced pressure had been reached was determined by using a pressure gauge 150 and a flow meter 160 in combination.

[0077] Comparative Example FIG. 9 is a conceptual diagram showing a comparative example. In the comparative example, a cell module 250 was placed in a chamber 310. The chamber 310 was depressurized, thereby depressurizing the interior of the exterior body 210. The chamber 310 was depressurized, thereby depressurizing the five cells 200 all at once. After depressurization, the exterior body 210 was sealed. The time required for depressurization was the same as in the example. It is also possible to provide a separate pressure gauge at the exhaust port 311 of the chamber 310, for example, and use that pressure gauge to determine whether the desired degree of depressurization has been reached.

[0078] <Evaluation> The presence or absence of blockage of the gas flow path was visually confirmed in each of the five cells 200. If swelling due to remaining air was confirmed in the cell 200, it was deemed that blockage of the gas flow path had occurred. If swelling due to remaining air was not confirmed in the cell 200, it was deemed that blockage of the gas flow path had not occurred.

[0079] In the examples, no blockage of the gas flow paths was observed, and it is believed that the internal pressure was ensured for all cells.

[0080] In the comparative example, blockage of the gas flow path was confirmed, and it is believed that the internal pressure was not guaranteed for all the cells in the comparative example.

[0081] The present embodiment and examples are illustrative in all respects. The present embodiment and examples are not limiting. The technical scope of the present disclosure encompasses all modifications within the meaning and scope equivalent to the claims. For example, it is also intended from the beginning that any configuration may be extracted from the present embodiment and examples and that they may be combined in any desired manner. [Explanation of symbols]

[0082] 10 positive electrode layer, 20 negative electrode layer, 30 separator, 100 manufacturing equipment, 110, 310 chamber, 111, 311 exhaust port, 120 sealing device, 130 pressure reducing device, 140 return piping, 141 first opening, 142 second opening, 143 pipeline, 150 pressure gauge, 160 flow meter, 200 cell, 201 work, 210 exterior body, 220 power generating element, 230 partition, 240 sealing material, 241 liquid injection port, 250 cell module, 251 first unit, 252 second unit, 253 third unit, P E External pressure, P I internal pressure.

Claims

1. A manufacturing apparatus for manufacturing an electrochemical cell with a reduced pressure inside an exterior body, a chamber; a pressure reducing device; Return piping and Including, the pressure reducing device is configured to reduce pressure inside the chamber; the return pipe includes a first opening, a conduit, and a second opening; the first opening and the second opening each independently open into the chamber, the first opening is configured to be connected to the exterior body, the conduit connects the first opening and the second opening, the conduit extends so as to once draw the gas within the exterior body to the outside of the chamber when the pressure inside the chamber is reduced, and then return the drawn gas into the chamber. Manufacturing equipment.

2. A plurality of the return pipes are included, Each of the plurality of return pipes includes, independently of one another, the first opening, the conduit, and the second opening. The manufacturing apparatus according to claim 1 .

3. further comprising a pressure gauge; The pressure gauge is connected to the pipeline. The manufacturing apparatus according to claim 1 or 2.

4. further comprising a flow meter; The flow meter is connected to the pipeline. The manufacturing apparatus according to any one of claims 1 to 3.

5. further comprising a sealing device; The sealing device is configured to seal the outer casing within the chamber. The manufacturing apparatus according to any one of claims 1 to 4.

6. (a) providing the manufacturing apparatus according to any one of claims 1 to 5; (b) preparing a work by housing a power generating element within the exterior body; (c) placing the workpiece in the chamber; (d) connecting the exterior body and the first opening; and (e) reducing the pressure inside the chamber to reduce the pressure inside the exterior body via the return pipe; Including, Method for manufacturing electrochemical cells.

7. In the method (a), the manufacturing apparatus is provided, which includes a plurality of return pipes that are independent of each other; In the step (b), a cell module including a plurality of the electrochemical cells is prepared as the workpiece; Each of the plurality of electrochemical cells independently includes an internal space; In (d), a separate return pipe is connected to each of the plurality of internal spaces. The method for producing an electrochemical cell according to claim 6 . (a) preparing the manufacturing apparatus described in claim 3; (b) preparing a work by housing a power generating element within the exterior body; (c) placing the workpiece in the chamber; (d) connecting the exterior body and the first opening; and (e) reducing the pressure inside the chamber to reduce the pressure inside the exterior body via the return pipe; Including, In the step (a), the manufacturing apparatus including the pressure gauge is prepared; In the step (e), the pressure inside the outer casing is reduced so that the reading of the pressure gauge becomes equal to or less than a reference value. Method for manufacturing electrochemical cells. (a) preparing the manufacturing apparatus described in claim 4; (b) preparing a work by housing a power generating element within the exterior body; (c) placing the workpiece in the chamber; (d) connecting the exterior body and the first opening; and (e) reducing the pressure inside the chamber to reduce the pressure inside the exterior body via the return pipe; Including, In the step (a), the manufacturing apparatus including the flow meter is prepared; In the step (e), after the pressure reduction is stopped, the pressure inside the outer casing is reduced so that the integrated value of the measurement values ​​of the flow meter becomes equal to or greater than a reference value. Method for manufacturing electrochemical cells.

10. a liquid inlet is formed in the exterior body, An electrolyte is injected into the exterior body through the injection port, In (d), the first opening of the return pipe is connected to the liquid inlet. A method for producing an electrochemical cell according to any one of claims 6 to 9.

11. The exterior body includes at least one selected from the group consisting of metal foil and metal foil laminate film, A method for producing an electrochemical cell according to any one of claims 6 to 10.

12. In the step (b), a bipolar cell module is prepared as the workpiece. A method for producing an electrochemical cell according to claim 7.

13. (f) sealing the outer casing under reduced pressure; further comprising: A method for producing an electrochemical cell according to any one of claims 6 to 12.

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