Method for manufacturing an electrical storage module and electrical storage module

Abstract

The present application relates to a manufacturing method of an electricity storage module and an electricity storage module. The manufacturing method of the electricity storage module includes: a preparation step of preparing at least one electricity storage unit cell each having a liquid injection port; a fixing step of fixing a sealing member to an injection member; a measurement step of measuring a shape of the sealing member; a decompression step of performing decompression in the electricity storage unit cell; a re-measurement step of re-measuring the shape of the sealing member after the decompression step; and a determination step of calculating a displacement amount of the sealing member based on a measurement result in the measurement step and a measurement result in the re-measurement step and determining that an internal pressure of the electricity storage unit cell is appropriate when the displacement amount is equal to or greater than a reference value.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing an energy storage module and an energy storage module. Background Technology

[0002] For example, Japanese Patent Application Publication No. 2021-64489 discloses a method for determining the generation of gas inside a secondary battery casing based on the amount of deformation of the casing. Summary of the Invention

[0003] Due to the use of secondary batteries (cell batteries), gas may be generated inside the cell battery casing. Therefore, it is necessary to ensure the internal pressure of the cell battery during manufacturing.

[0004] This disclosure provides a method for manufacturing an energy storage module and an energy storage module that can ensure appropriate internal pressure of each energy storage unit battery.

[0005] A method for manufacturing a storage module according to one aspect of this disclosure includes: a preparation step, which is a step of preparing at least one storage unit battery, each including a filling member having a filling port for injecting electrolyte into the storage unit battery; a fixing step, which is a step of fixing the sealing member to the filling member by covering the filling port with a sealing member having flexibility and configured to seal the filling port; a measurement step, which is a step of measuring the shape of the sealing member fixed to the filling member; a decompression step, which is a step of decompressing the storage unit battery after the measurement step; a sealing step, which is a step of sealing the storage unit battery after the decompression step; a re-measurement step, which is a step of measuring the shape of the sealing member again after the sealing step; and a determination step, which is a step of calculating the displacement of the sealing member based on the measurement results in the measurement step and the measurement results in the re-measurement step, and determining that the internal pressure of the storage unit battery is appropriate when the displacement is above a reference value.

[0006] Additionally, according to other aspects of this disclosure, the energy storage module comprises: at least one energy storage unit battery, each having an injection port for injecting electrolyte into the energy storage unit battery; and a sealing member having flexibility and sealing the injection port of the at least one energy storage unit battery. Each of the at least one energy storage unit battery includes an injection member having the injection port, the injection member having a bearing surface surrounding the injection port and bearing the sealing member, the sealing member including a peripheral contact portion in contact with the bearing surface and an inner portion located inside the peripheral contact portion, the inner portion being recessed from the peripheral contact portion, and the internal pressure of the energy storage unit battery being below atmospheric pressure.

[0007] According to this disclosure, a method for manufacturing an energy storage module and an energy storage module are provided that can ensure appropriate internal pressure of each energy storage unit battery. Attached Figure Description

[0008] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, in which the same reference numerals denote the same elements, and wherein:

[0009] Figure 1 This is a perspective view schematically showing a battery cell manufactured using the battery cell manufacturing method of an embodiment of the present disclosure.

[0010] Figure 2 yes Figure 1 The diagram shows a top view of the energy storage module.

[0011] Figure 3 yes Figure 2 A cross-sectional view at line III-III.

[0012] Figure 4 This is a 3D view showing the state of the battery module before the filling port is sealed.

[0013] Figure 5 It is a cross-sectional view of the injection and sealing components after the sealing process.

[0014] Figure 6 It is a three-dimensional diagram that roughly shows the measurement process.

[0015] Figure 7 It is a cross-sectional view of the injection and sealing components after the decompression process.

[0016] Figure 8 It is a graph showing the relationship between the pressure reduction of the internal pressure of the battery cell from atmospheric pressure and the displacement of the sealing component.

[0017] Figure 9 This is a top view that roughly shows a modified example of the injection component.

[0018] Figure 10 This is a top view that roughly shows a modified example of the injection component.

[0019] Figure 11 This is a top view that roughly shows a modified example of the injection component. Detailed Implementation

[0020] Embodiments of this disclosure will be described with reference to the accompanying drawings. Furthermore, in the drawings referred to below, the same reference numerals are used to denote the same or equivalent components.

[0021] Figure 1This is a perspective view schematically showing a battery cell manufactured using the battery cell manufacturing method of an embodiment of the present disclosure. Figure 2 yes Figure 1 The diagram shows a top view of the energy storage module. Figure 3 yes Figure 2 A cross-sectional view at line III-III. This energy storage module 1 is, for example, mounted in a vehicle.

[0022] like Figures 1-3 As shown, the energy storage module 1 of this embodiment includes multiple energy storage unit batteries 10 and sealing members 20.

[0023] Multiple energy storage cells 10 are arranged in one direction ( Figure 3 The energy storage module 1 is arranged in a left-right orientation. In this embodiment, the energy storage module 1 includes 30 energy storage cell batteries 10 arranged in said orientation. The internal pressure of each energy storage cell battery 10 is maintained at an appropriate value below atmospheric pressure. Figure 3 As shown, each energy storage unit battery 10 is composed of a bipolar cell. That is, each energy storage unit battery 10 has a current collector 11, a positive electrode active material layer 12, a negative electrode active material layer 13, a separator 14, a fixing member 15, a liquid injection member 16, and an electrolyte (not shown). Furthermore, although in Figure 3 The text is omitted, but there are actually 30 energy storage units 10 arranged in one direction.

[0024] The current collector 11 is formed in the shape of a flat plate. In the case of the positive electrode, the current collector 11 is made of aluminum foil, for example, and in the case of the negative electrode, the current collector 11 is made of copper foil, for example. However, the current collector 11 may also be made of nickel foil, stainless steel foil, or a composite foil obtained by combining aluminum foil and copper foil.

[0025] The positive electrode active material layer 12 is disposed on one side of the current collector 11. The negative electrode active material layer 13 is disposed on the other side of the current collector 11.

[0026] The separator 14 is disposed between the positive electrode active material layer 12 disposed on a current collector 11 and the negative electrode active material layer 13 disposed on a current collector 11 adjacent to the current collector 11.

[0027] In a plurality of energy storage cell batteries 10 arranged in one direction, a current collector 11 disposed at one end on one side of the current collector 11 in the thickness direction is connected to a positive electrode tab (not shown). A current collector 11 disposed at the other end of the plurality of energy storage cell batteries 10 arranged in one direction in the thickness direction is connected to a negative electrode tab (not shown).

[0028] The fixing member 15 fixes the periphery of each current collector 11 to each other. The fixing member 15 is made of resin, for example. The fixing member 15 is provided with a communication port 15h that allows the inside of the energy storage unit battery 10 to communicate with the outside.

[0029] The injection component 16 is fixed to the fixing component 15. More specifically, the injection component 16 is fixed to the fixing component 15 in a manner that surrounds the communication port 15h. The injection component 16 is, for example, made of resin. Figure 1 and Figure 3 As shown, the electrolyte injection member 16 has an injection port 16h for injecting electrolyte from outside the storage unit battery 10 into the storage unit battery 10. The injection port 16h is connected to the communication port 15h. In this embodiment, the electrolyte injection member 16 is formed as a cylindrical shape, more specifically a square cylindrical shape, defining the injection port 16h. However, the electrolyte injection member 16 is not limited to a square cylindrical shape, and may also be formed as a cylindrical shape, etc. Furthermore, in Figure 3 In order to facilitate understanding of the invention, a schematic diagram is shown in which a liquid injection member 16 is installed on a portion of the fixing member 15 surrounding a single energy storage unit battery 10. However, it is not limited to this, and it is also possible to install a liquid injection member 16 on a portion of the fixing member 15 surrounding multiple stacked energy storage unit batteries 10.

[0030] like Figure 1 and Figure 3 As shown, the injection member 16 has a bearing surface 16a that bears the sealing member 20. The bearing surface 16a is formed flat.

[0031] The sealing member 20 is flexible and capable of sealing the injection port for 16 hours. The sealing member 20 is made of resin formed in a sheet-like shape. For example... Figure 2 and Figure 3 As shown, the sealing member 20 has an annular peripheral contact portion 21 and an inner portion 22.

[0032] The peripheral contact portion 21 contacts the receiving surface 16a of the liquid injection component 16. The peripheral contact portion 21 is fused to the receiving surface 16a.

[0033] The inner portion 22 is located inside the peripheral contact portion 21. For example... Figure 3 As shown, the inner side 22 is recessed from the peripheral contact portion 21.

[0034] Next, refer to Figures 4-8 , to Figures 1-3 Manufacturing methods for the energy storage module 1 with different embodiments will be described. The manufacturing method includes a preparation process, a fixing process, a measurement process, a pressure reduction process, a sealing process, a re-measurement process, and a judgment process.

[0035] In the preparation process, a storage module 1 with four storage units 10 is prepared. Figure 4The diagram shows four energy storage cell batteries 10 being held between two sides of a pair of pressure plates 50 in one direction. Furthermore, in... Figure 4 The illustration of one of the pair of pressure plates 50 is omitted. Additionally, Figure 4 A schematic diagram showing four energy storage cell batteries 10 arranged in one direction is provided. The number of liquid injection components 16 in each energy storage cell battery 10 is related to... Figure 1 Different. In this state, electrolyte is injected into the battery 10 of the energy storage unit through each injection port 16h and the connecting port 15h.

[0036] In the fixing process, the sealing member 20 is fixed to the injection member 16. Specifically, the sealing member 20 is placed and fixed to the bearing surface 16a of the injection member 16. For example, the sealing member 20 is fixed to the bearing surface 16a of the injection member 16 by being fused to it. At this time, a portion of the bearing surface 16a and a portion of the sealing member 20 are not fused together, thus forming a gap.

[0037] In the testing process, the shape of the sealing member 20, which is installed on the liquid filling member 16 in a manner covering the liquid filling port for 16 hours before the pressure inside the storage unit battery 10 is reduced, is measured. Figure 6 As shown, in the measurement process, the measuring device 100 is used to measure the three-dimensional shape of the sealing member 20 by means of optical cutting method, pattern projection method, etc.

[0038] In the depressurization process, the energy storage module 1 after the measurement process is depressurized, and the energy storage unit battery 10 is depressurized. In this process, for example, the energy storage module 1 with the sealing member 20 fixed to the liquid injection member 16 is placed in the chamber, and the pressure inside the energy storage unit battery 10 is reduced to below atmospheric pressure by evacuating the chamber. At this time, the gas inside the energy storage unit battery 10 is discharged to the outside of the energy storage unit battery 10 through the gap between the receiving surface 16a of the liquid injection member 16 and the sealing member 20. Alternatively, vent holes may be provided in the sealing member 20 and the liquid injection member 16, through which the gas inside the energy storage unit battery 10 is discharged to the outside of the energy storage unit battery 10.

[0039] The sealing process is performed after the depressurization process or while the chamber is under vacuum. Specifically, the injection port 16h is sealed by welding the gap between the peripheral contact portion 21 of the sealing member 20 and the receiving surface 16a of the injection member 16. Thus, the battery cell 10 is sealed while the pressure inside the battery cell 10 is reduced.

[0040] In the re-measurement process, the shape of the sealing member 20 in the energy storage module 1 after the depressurization process, in the state where the energy storage unit battery 10 was sealed during the sealing process, is measured again. Specifically, the energy storage module 1 is removed from the chamber, for example, under atmospheric pressure. At this time, as Figure 7 As shown, the sealing member 20 is deformed such that its inner side 22 is recessed into the battery cell 10 relative to the peripheral contact portion 21. Then, similar to the measurement process described above, the three-dimensional shape of the sealing member 20 is measured using the measuring device 100. Furthermore, in Figure 7 In the image, the sealing component 20 before deformation is shown with a double-dotted line.

[0041] In the judgment process, the displacement D of the sealing member 20 is calculated based on the measurement results in the measurement process and the measurement results in the re-measurement process (refer to...). Figure 7 Furthermore, when the displacement D is greater than or equal to the reference value D1, it is determined that the internal pressure P of the energy storage unit battery 10 is appropriate. In addition, the displacement D is preferably, for example, a displacement of the center of the inner side portion 22 before and after the pressure reduction process.

[0042] Figure 8 This is a graph showing the relationship between the displacement D of the sealing member 20 and the pressure reduction P of the storage unit battery 10 from atmospheric pressure. (See graph for details.) Figure 8 As shown, the higher the pressure reduction of the storage unit battery 10, the larger the displacement D. Simulation and preliminary experiments confirmed that when the displacement D is greater than or equal to D1, the internal pressure P of the storage unit battery 10 is a suitable value P1 below atmospheric pressure. Therefore, in the judgment process, when the displacement D is greater than or equal to the reference value D1, the internal pressure P of the storage unit battery 10 is judged to be appropriate (OK). Furthermore, in Figure 8 In the diagram, the range where the internal pressure of the storage unit battery 10 is greater than the appropriate value P1 is marked with a slash (NG).

[0043] As described above, in the manufacturing method of this energy storage module 1, during the determination process, the displacement amount D of the sealing member 20 is calculated based on the shape of the sealing member 20 before and after the pressure reduction process. When the displacement amount D is greater than or equal to a reference value D1, it is determined that the internal pressure P of the energy storage unit battery 10 is appropriate. Therefore, an energy storage module 1 with appropriate internal pressure P of each energy storage unit battery 10 is manufactured.

[0044] Furthermore, in the above embodiment, a bipolar energy storage module is exemplified as energy storage module 1, but energy storage module 1 is not limited to this. In addition, the bipolar module has a structure in which a positive electrode active material layer 12 is provided on one side of a current collector 11 and a negative electrode active material layer 13 is provided on the other side, and multiple layers are stacked with spacers 14 between them.

[0045] In addition, such as Figure 9 As shown, the three liquid injection components 16 arranged in the same direction (the stacking direction of the current collector 11, the positive electrode active material layer 12, and the negative electrode active material layer 13) can be interconnected. In this case, the liquid injection port 16h of each of the three interconnected liquid injection components 16 can be sealed by a single sealing component 20.

[0046] Or, it could be, such as Figure 10 As shown, 10 injection components 16 arranged in a direction orthogonal to the aforementioned direction are interconnected.

[0047] Or, it could be, such as Figure 11 As shown, all the injection components 16 are interconnected.

[0048] Those skilled in the art will understand that the above-described embodiments are specific examples of the following solutions.

[0049] The method for manufacturing a storage module in the above embodiments includes: a preparation step, which is a step of preparing at least one storage unit battery, each including a filling member having a filling port for injecting electrolyte into the storage unit battery; a fixing step, which is a step of fixing the sealing member to the filling member by covering the filling port with a flexible sealing member configured to seal the filling port; a measurement step, which is a step of measuring the shape of the sealing member fixed to the filling member; a decompression step, which is a step of decompressing the storage unit battery after the measurement step; a sealing step, which is a step of sealing the storage unit battery after the decompression step; a re-measurement step, which is a step of measuring the shape of the sealing member again after the sealing step; and a determination step, which is a step of calculating the displacement of the sealing member based on the measurement results in the measurement step and the measurement results in the re-measurement step, and determining that the internal pressure of the storage unit battery is appropriate when the displacement is above a reference value.

[0050] In this method for manufacturing an energy storage module, during the judgment process, the displacement of the sealing member is calculated based on the shape of the sealing member before and after the pressure reduction process. When the displacement is above a reference value, the internal pressure of the energy storage unit battery is determined to be appropriate. Therefore, it is possible to manufacture an energy storage module with appropriate internal pressure for each energy storage unit battery.

[0051] Furthermore, in the fixing process, the sealing member can be fixed to the liquid injection member by forming a gap between the liquid injection member and the sealing member. In the depressurization process, gas inside the battery can be released through the gap to depressurize the battery. In the sealing process, the battery can be sealed by welding the sealing member to the liquid injection member to close the gap.

[0052] In this design, the injection port is also used for pressure reduction, thus simplifying the structure compared to the case where a dedicated pressure reduction opening is provided for the battery cell.

[0053] Alternatively, the at least one energy storage unit battery prepared in the preparation step may comprise a plurality of energy storage unit batteries, with two or more of the liquid injection components of each of the plurality of energy storage unit batteries interconnected. In this case, during the fixing step, the liquid injection ports of the two or more interconnected liquid injection components may be generally covered by a single sealing component.

[0054] In this design, the number of sealing components is reduced compared to preparing sealing components corresponding to each injection port, thus simplifying the management and handling of the sealing components. Furthermore, adjacent injection components share the same boundary frame, reducing the welded areas between the sealing components and the injection components, thereby facilitating production.

[0055] In addition, in the preparation process, a bipolar battery can be prepared as the energy storage unit battery.

[0056] In an energy storage module that includes bipolar cell batteries as energy storage units, the internal pressure of the energy storage unit batteries other than the energy storage unit battery located at the outermost position in one direction is difficult to judge based on appearance, so the above effect is particularly significant.

[0057] Additionally, according to other aspects of this disclosure, the energy storage module comprises: at least one energy storage unit battery, each having an injection port for injecting electrolyte into the energy storage unit battery; and a sealing member having flexibility and sealing the injection port of the at least one energy storage unit battery. Each of the at least one energy storage unit battery includes an injection member having the injection port. The injection member has a bearing surface surrounding the injection port and bearing the sealing member. The sealing member includes a peripheral contact portion in contact with the bearing surface and an inner portion located inside the peripheral contact portion, the inner portion being recessed from the peripheral contact portion. The internal pressure of the energy storage unit battery is below atmospheric pressure.

[0058] Furthermore, the embodiments disclosed herein should be considered illustrative in all respects, and not restrictive. The scope of the invention is defined not by the description of the embodiments above, but by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

Claims

1. A method for manufacturing an energy storage module, characterized in that the method comprises: The preparation process is the process of preparing at least one storage cell battery, each including a liquid injection component having a liquid injection port for injecting electrolyte into the storage cell battery. The fixing process is a process of installing and fixing the sealing member to the injection member by covering the injection port with a flexible sealing member configured to seal the injection port; The measurement process is a process of measuring the shape of the sealing member fixed to the injection member; The pressure reduction process is a process of reducing the pressure inside the battery of the energy storage unit after the measurement process; A sealing process, which is a process of sealing the energy storage unit battery after the pressure reduction process; The re-measurement process is a process of measuring the shape of the sealing member again after the sealing process; as well as The determination process involves calculating the displacement of the sealing member based on the measurement results from the measurement process and the measurement results from the re-measurement process, and determining that the internal pressure of the battery in the energy storage unit is appropriate when the displacement is above a reference value. In the fixing process, the sealing member is fixed to the injection member in such a way that a gap is formed between the injection member and the sealing member; In the pressure reduction process, the gas inside the storage unit battery is discharged through the gap to reduce the pressure inside the storage unit battery; and... In the sealing process, the battery cell is sealed by fusing the sealing member to the liquid injection member in a manner that closes the gap. The displacement amount is the amount by which the central portion of the sealing member shifts inward toward the interior of the battery cell. In the measurement process and the re-measurement process, the three-dimensional shape of the sealing member is measured by the measuring device.

2. The method for manufacturing a battery storage module according to claim 1, characterized in that: The at least one energy storage unit battery prepared in the preparation process includes multiple energy storage unit batteries, and two or more of the liquid injection components of each of the multiple energy storage unit batteries are interconnected; and... In the fixed process, the injection ports of two or more interconnected injection components are generally covered by one sealing component.

3. The method for manufacturing a battery storage module according to claim 1 or 2, characterized in that: In the preparation process, a bipolar energy storage unit battery is prepared as the energy storage unit battery.

4. An electricity storage module characterized by comprising: have: Each of the following is a storage cell battery having at least one inlet for injecting electrolyte into the storage cell battery; and A sealing member having flexibility and sealing the injection port of at least one energy storage unit battery. Each of the at least one energy storage unit battery includes an injection component having the injection port; The injection component has a bearing surface that surrounds the injection port and supports the sealing component; The sealing member includes a peripheral contact portion that contacts the bearing surface and an inner portion located inside the peripheral contact portion, the inner portion being recessed from the peripheral contact portion; The at least one energy storage unit battery includes a plurality of current-collecting components and a fixing component arranged at intervals. The fixing component fixes the peripheral portions of the plurality of current-collecting components to each other. The fixing component is provided with a communication port that connects the inside of the at least one energy storage unit battery to the outside and to the liquid injection port. The liquid injection component is fixed to the fixing component in a manner that surrounds the communication port. The internal pressure of the battery in the energy storage unit is below atmospheric pressure.

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