JP6107606B2 - Method for manufacturing power storage device - Google Patents

Description

  The present invention relates to a method for manufacturing a power storage device.

  Non-aqueous electrolytic secondary batteries such as lithium ion secondary batteries are known as power storage devices. The power storage device is configured such that an electrode assembly having a positive electrode, a negative electrode, and a separator disposed therebetween is accommodated in a case. The case is formed with a liquid injection port for injecting an electrolytic solution into the case. As described in Patent Document 1, the liquid injection port is sealed with a sealing plug as a sealing member, and the case is hermetically sealed.

  Such a power storage device is manufactured as follows, for example. That is, first, the electrode assembly is accommodated in a case, and a power storage device in a state where no electrolyte is injected is manufactured. Thereafter, an electrolytic solution is injected into the case from the injection port. Subsequently, the initial charging (activation) is performed and the aging process is performed with the liquid injection port temporarily sealed. After carrying out the aging treatment, the temporary sealing is released, and the liquid injection port is finally sealed with a sealing member, whereby a power storage device as a product is obtained.

JP2013-110101A

  However, when the initial charging and aging processing of the power storage device is performed in the manufacturing process of the power storage device, the case is swollen. Due to the swelling, it is difficult to align the center of the liquid inlet and the center of the sealing member when the liquid inlet is finally sealed with the sealing member. As a result, it may take time to manufacture the power storage device.

  Therefore, in this technical field, there is a demand for a method for manufacturing a power storage device that can efficiently manufacture the power storage device.

  A method for manufacturing a power storage device according to one aspect of the present invention includes an electrode assembly having a positive electrode, a negative electrode, and a separator disposed therebetween, and a power storage structure having a case for housing the electrode assembly, and a case It is a manufacturing method of the electrical storage apparatus provided with the sealing member which seals the injection port of the electrolyte solution which has, and electrolyte solution was inject | poured in the case. A step of fixing a sealing jig having a through hole for guiding the sealing member to the liquid injection port to the case of the power storage structure so that the through hole communicates with the liquid injection port; A step of temporarily sealing the liquid inlet by attaching a temporary sealing member to one of the through hole and the liquid inlet, and a power storage structure with the liquid inlet temporarily sealed The step of activating and carrying out the aging treatment, the step of removing the temporary sealing member from the storage structure subjected to the aging treatment, and the sealing member at the liquid injection port of the case through the through hole of the sealing jig A step of attaching and main-sealing the liquid injection port with a sealing member, and removing the sealing jig from the case.

  In the above manufacturing method, since the sealing jig is attached to the case before the activation / aging process of the power storage structure, it is possible to reliably align the through hole and the liquid injection port. In this state, the activation and aging processing of the power storage structure is performed in a state where the centers of the through hole and the liquid injection port are aligned. When the liquid injection port is fully sealed with the sealing member, the sealing member is attached to the liquid injection port through the through hole, so that the center of the liquid injection port and the center of the sealing member are easily aligned. . As a result, the power storage device can be manufactured efficiently.

  In one embodiment, the through hole may have a first opening in contact with the liquid injection port, and a second opening opposite to the first opening in the central axis direction of the through hole. The diameter of the second opening may be larger than the diameter of the first opening. The through-hole may have a tapered portion whose hole diameter decreases from the second opening toward the first opening side in the central axis direction.

  Since the diameter of the second opening is larger than the diameter of the first opening, it is easy to pass the sealing member through the through hole. In this case, since the through hole has a tapered portion, even if the sealing member is passed through the through hole from the second opening, the sealing member is easily guided to the liquid injection port by the tapered portion.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the electrical storage apparatus which can manufacture an electrical storage apparatus efficiently can be provided.

FIG. 1 is a perspective view of a power storage device manufactured by a method for manufacturing a power storage device according to an embodiment. FIG. 2 is a flowchart illustrating an example of a method for manufacturing the power storage device illustrated in FIG. 1. FIG. 3 is a schematic diagram of a power storage structure manufactured in the power storage structure manufacturing step. FIG. 4 is a drawing for explaining a jig mounting step. FIG. 5 is a partially enlarged view of a cross-sectional configuration taken along line VV in FIG. FIG. 6 is a drawing for explaining the temporary sealing step. FIG. 7 is a drawing for explaining a step of main sealing the liquid injection port with a sealing member.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a perspective view of a power storage device manufactured by a method for manufacturing a power storage device according to an embodiment. An example of the power storage device 10 is a nonaqueous electrolytic secondary battery such as a lithium ion secondary battery. The power storage device 10 includes a metal case 12 and an electrode assembly 14 accommodated in the case 12.

  The case 12 has an internal space for accommodating the electrode assembly 14. An example of the shape of the case 12 is a substantially rectangular parallelepiped shape. Examples of the material of the case 12 are aluminum and stainless steel. The internal space of the case 12 is filled with, for example, an organic solvent-based or non-aqueous electrolyte.

  As shown in FIG. 1, the positive terminal 18 </ b> A and the negative terminal 18 </ b> B are arranged on the top surface (or lid) 16 of the case 12 so as to be separated from each other. The positive electrode terminal 18 </ b> A and the negative electrode terminal 18 </ b> B are provided on the case 12 such that one end portions thereof protrude from the top surface portion 16 to the outside of the case 12. The positive terminal 18A and the negative terminal 18B are insulated from the case 12.

  The top surface portion 16 of the case 12 is formed with a liquid injection port 16 a for injecting an electrolytic solution into the case 12. The liquid injection port 16 a is sealed with a sealing member 20. An example of the sealing member 20 is a rivet, but the sealing member 20 is not limited to a rivet as long as the liquid injection port 16a can be sealed.

  In one embodiment, an example of the electrode assembly 14 is a sheet-like positive electrode and a negative electrode laminated in a feature (laminated structure) with a sheet-like separator (diaphragm) sandwiched (interposed state). is there. However, the configuration of the electrode assembly 14 is an electrode assembly having a positive electrode, a negative electrode, and a separator disposed between them, which is used in a nonaqueous electrolytic secondary battery such as a lithium ion secondary battery. There is no particular limitation. The electrode assembly 14 is accommodated in the case 12 while being covered with an insulating sheet, and the insulating sheet is insulated from the case 12. The positive electrode of the electrode assembly 14 is electrically connected to the positive electrode terminal 18A, and the negative electrode of the electrode assembly 14 is electrically connected to the negative electrode terminal 18B. These connection methods are not limited as long as the power storage device 10 is electrically connected so as to function.

  For convenience of description, in the following description, as shown in FIG. 1, the short side direction of the top surface portion 16 is referred to as the X-axis direction, the long side direction is referred to as the Y-axis direction, and the X-axis direction and the Y-axis direction. The direction orthogonal to the Z axis direction may be referred to as the Z axis direction.

  FIG. 2 is a flowchart illustrating an example of a method for manufacturing the power storage device illustrated in FIG. 1. As shown in FIG. 2, the method for manufacturing the power storage device includes a power storage structure manufacturing step S10, a jig mounting step S12, a temporary sealing step S14, an activation / aging step S16, and a temporary sealing release step S18. And a main sealing step S20. Each step will be described.

(Storage structure manufacturing process)
FIG. 3 is a schematic diagram of a power storage structure manufactured in the power storage structure manufacturing step. The configuration of the power storage structure 22 shown in FIG. 3 is the same as that of the power storage device 10 shown in FIG. 1 before the electrolytic solution is injected and before the liquid injection port 16a is sealed with the sealing member 20. This corresponds to the power storage device in the state. In other words, the configuration of the power storage structure 22 and the configuration of the power storage device 10 are such that the electrolytic solution is not injected in the power storage structure 22 and the liquid injection port 16 a is sealed with the sealing member 20. It is the same except that there is no point. Therefore, the power storage structure 22 is a power storage member that constitutes a part of the power storage device 10. The power storage structure 22 houses the electrode assembly 14 in the case 12 and electrically connects the positive electrode terminal 18A and the negative electrode terminal 18B attached to the case 12 to the positive electrode and the negative electrode of the electrode assembly 14, respectively. Can be made.

(Jig installation process)
FIG. 4 is a drawing for explaining a jig mounting step. As shown in FIG. 4, in the jig attaching step S <b> 12, the sealing jig 24 is attached to the case 12 included in the power storage structure 22. The sealing jig 24 is a jig for taking the sealing member 20 into the liquid injection port 16a. The sealing jig 24 is configured to be detachable from the case 12.

  In one embodiment, the sealing jig 24 includes a guide portion 26 having a through hole 28 that guides the sealing member 20 to the liquid injection port 16a, and a pair of arm portions 30A and 30B that continuously extend from the guide portion 26. Have An example of the shape of the guide part 26 is a quadrangular prism as shown in FIG. The pair of arm portions 30A and 30B is a pair of side surfaces facing each other of the guide portion 26, and extends in the Z-axis direction from a pair of side surfaces orthogonal to the X-axis direction. An example of the shape of the arm portions 30A and 30B is a plate shape. The distance between the pair of arm portions 30A and 30B is substantially equal to the width of the case 12 in the X-axis direction. The guide portion 26 and the pair of arm portions 30A and 30B may be integrally formed as shown in FIG. 3, or may be joined as a separate member. An example of the material of the sealing jig 24 is resin.

  In the sealing jig 24, the central axis C1 of the liquid injection port 16a and the central axis C2 of the through hole 28 substantially coincide with each other, and the pair of arm portions 30A and 30B face the side surface portions 32 and 34 of the case 12, respectively. The case 12 may be attached as described above. The side portions 32 and 34 are orthogonal to the X-axis direction. The attachment of the sealing jig 24 to the case 12 can be easily performed by, for example, spreading the pair of arm portions 30A and 30B outward.

  Since the central axis C1 of the liquid injection port 16a and the central axis C2 of the through hole 28 substantially coincide with each other, the liquid injection port 16a and the through hole 28 communicate with each other. Since the width between the pair of arm portions 30A and 30B is substantially equal to the width of the case 12, the pair of arm portions 30A and 30B can be connected to the case 12 with the sealing jig 24 mounted on the case 12. It abuts on the side surfaces 32 and 34. In other words, the case 12 is sandwiched between the pair of arm portions 30A and 30B. Thereby, the sealing jig 24 is fixed to the case 12. Therefore, the arm portions 30 </ b> A and 30 </ b> B function as a fixing portion for fixing the sealing jig 24 to the case 12. The length of the arm portions 30 </ b> A and 30 </ b> B in the Z-axis direction may be a length that can stably fix the sealing jig 24 to the case 12. In one embodiment, examples of the lengths of the arm portions 30A and 30B in the Z-axis direction are such that the free ends (the ends opposite to the guide portion 26) of the arm portions 30A and 30B reach the bottom surface portion 36 of the case 12. Length. The free ends of the arm portions 30A and 30B may be bent in an L shape toward the inside. In this case, since the free end portion is hooked on the bottom surface portion 36 of the case 12, the sealing jig 24 can be more securely fixed to the case 12.

  FIG. 5 is a partially enlarged view of a cross-sectional configuration taken along line VV in FIG. An example of the configuration of the through hole 28 will be described with reference to FIG.

  The through hole 28 includes a first hole portion 28A, a second hole portion (tapered portion) 28B, and a third hole portion 28C. 28 A of 1st hole parts contain the opening (1st opening) 28a located in the injection port 16a side among opening 28a, 28b which the through-hole 28 has. The diameter of the opening 28a is larger than the diameter of the liquid injection port 16a or the same as the diameter of the liquid injection port 16a. The diameter of the first hole 28A may be substantially constant in the direction of the central axis C2. The third hole portion 28C has an opening (second opening) 28b opposite to the opening 28a in the direction of the central axis C2 among the openings 28a and 28b of the through hole 28. The diameter of the opening 28b is larger than the diameter of the opening 28a. The diameter of the third hole 28C may be substantially constant in the direction of the central axis C2. A screw portion is formed on the wall surface of the third hole portion 28C. As long as the screw part is formed in a predetermined region from the opening 28b toward the second hole part 28B, the screw part may not be formed on the entire wall surface of the third hole part 28C in the direction of the central axis C2. The second hole 28B connects the third hole 28C and the first hole 28A, and the diameter of the second hole 28B is the first hole from the third hole 28C side. It is smaller toward the portion 28A. That is, the second hole portion 28B is a tapered portion having a tapered shape.

(Temporary sealing process)
After the jig attaching step S12, a temporary sealing step S14 is performed. The temporary sealing step S14 is a step of injecting the electrolytic solution into the power storage structure 22 to which the sealing jig 24 is attached and temporarily sealing the liquid injection port 16a. An example of the temporary sealing step S14 will be described with reference to FIG. FIG. 6 is a drawing for explaining the temporary sealing step.

  In the temporary sealing step S <b> 14, the pipe 38 is fixed to the through hole 28. The pipe 38 has a cylindrical pipe body 38A. A ring portion 38B is formed on the outer peripheral surface of the pipe main body 38A in a part of the pipe main body 38A in the axial direction. The ring portion 38B is formed integrally with the pipe main body portion 38A. In this case, the wall portion of the pipe 38 is thicker at the ring portion 38B. In other words, the pipe 38 has a small diameter part and a large diameter part. The “diameter” of the small diameter and the large diameter related to the pipe 38 means the outer diameter of the pipe 38. The ring portion 38B is formed with a screw portion that is screwed into a screw portion formed in the third hole portion 28C. Therefore, the pipe 38 can be fixed to the sealing jig 24 by inserting one end of the pipe 38 into the liquid injection port 16a and screwing the ring part 38B into the third hole part 28C. Thereby, since the through-hole 28 is temporarily sealed, as a result, the liquid injection port 16a is temporarily sealed. Therefore, the pipe 38 functions as a temporary sealing member. The ring portion 38B has been described as being integrally formed with the pipe main body portion 38A. However, the pipe main body portion 38A and the ring portion 38B are separate from each other, and the pipe main body portion 38A is inserted into the cylindrical ring portion 38B. May be. The shapes of the pipe main body portion 38A and the ring portion 38B are not limited to cylindrical shapes.

  After the pipe 38 is attached to the sealing jig 24, the end of the pipe 38 opposite to the liquid injection port 16a is connected to an electrolyte supply source (not shown) that stores the electrolyte. Thereafter, the electrolytic solution 40 is injected into the case 12 through the pipe 38. In FIG. 6, the electrolytic solution 40 is schematically shown by white arrows. The pipe 38 may be attached to the sealing jig 24 after the pipe 38 is connected to the electrolyte supply source.

  After the injection of the electrolytic solution 40, the end of the pipe 38 connected to the electrolytic solution supply source is connected to a gas processing device (not shown). In one embodiment, the end of the piping 38 that was connected to the electrolyte supply source may be closed by a plug.

  Here, the pipe 38 has been described as a temporary sealing member, but as described above, in the form in which the end of the pipe 38 connected to the electrolyte supply source is connected to the gas processing apparatus or closed by a stopper, A gas processing device or a stopper may be included and regarded as a temporary sealing member. Further, the end of the pipe 38 connected to the electrolytic solution supply source may be regarded as a state in which the liquid injection port 16a is temporarily sealed at the stage where the end of the pipe 38 is connected to the gas processing apparatus or closed with a stopper.

(Activation and aging process)
After the temporary sealing step S14, the activation / aging step S16 is performed on the power storage structure 22 in which the electrolytic solution is injected and the liquid injection port 16a is temporarily sealed. Specifically, the aging process is performed on the power storage structure 22 after initial charging.

  The initial charging may be performed at a predetermined current, voltage, time, and temperature. Thereby, the electrical storage structure 22 is activated. The aging process may be performed at a predetermined temperature and time.

  In the initial charging and aging process, particularly the aging process, gas (for example, methane gas, carbon monoxide gas, hydrogen gas, etc.) is generated in the case 12. Therefore, in the activation / aging step S16, the gas processing apparatus connected to the pipe 38 is driven.

(Temporary sealing release process)
After the activation / aging step S16, a temporary sealing release step S18 is performed. That is, by temporarily removing the pipe 38 from the sealing jig 24, the temporary sealing of the liquid injection port 16a is released.

(Main sealing process)
After removing the pipe 38 from the sealing jig 24, the main sealing step S20 is performed. Specifically, as shown in FIG. 7, the sealing member 20 is attached to the liquid injection port 16 a through the through hole 28, and the liquid injection port 16 a is fully sealed by the sealing member 20. That is, the liquid injection port 16a is closed by the sealing member 20, and the case 12 is sealed. An example of the sealing member 20 is a rivet. For example, a rivet as the sealing member 20 may be press-fitted into the liquid injection port 16a. As described above, after the liquid injection port 16 a is fully sealed, the sealing jig 24 is removed from the case 12. Thereby, the electrical storage apparatus 10 shown in FIG. 1 is obtained. As described above, the sealing member 20 for main sealing the liquid injection port 16a is not limited to a rivet as long as the liquid injection port 16a can be closed. For example, if the screw part is formed in the liquid injection port 16a, the sealing member 20 may be a screw. Further, the sealing member 20 may be fixed to the liquid injection port 16a by a welding technique such as laser welding.

  In the power storage device 10 manufactured by the above manufacturing method, the electrolytic solution is injected into the case 12 from the liquid injection port 16 a of the case 12 into the power storage structure 22, and the liquid injection port 16 a is sealed with the sealing member 20. It has a configuration.

  Next, the effect of the manufacturing method will be described in comparison with the case where the sealing jig 24 is not attached.

  When the activation / aging process is performed on the power storage structure 22 into which the electrolytic solution 40 has been injected, the case 12 may normally swell due to the influence thereof, and the case 12 may be distorted. Therefore, when the liquid injection port 16a is sealed by the sealing member 20 after the activation and aging treatment, it may be difficult to align the center of the liquid injection port 16a with the center of the sealing member 20. .

  On the other hand, in the embodiment in which the sealing jig 24 is attached to the case 12, the sealing jig 24 is attached before the activation / aging process, so that the central axis C2 of the through hole 28 is the central axis of the liquid injection port 16a. The sealing jig 24 is attached to the case 12 with accurate alignment with respect to C1. Therefore, even in the main sealing step S20 after the activation / aging process is performed, the sealing member 20, the liquid injection port 16a, and the liquid injection port 16a Easy to align the center. As a result, the power storage device 10 can be efficiently manufactured.

  Due to the activation and aging treatment, the swelling of the case 12 tends not to occur more in the X-axis direction than in the Y-axis direction. Therefore, as shown in FIG. 3, the sealing jig 24 is attached to the case 12 so that the arm portions 30 </ b> A and 30 </ b> B are in contact with the side surface portions 32 and 34 (side surfaces orthogonal to the X-axis direction) of the case 12. In this embodiment, the central axes C1 and C2 of the liquid injection port 16a and the through hole 28 are not easily displaced before and after the activation and aging treatment. Therefore, it is easy to align the center of the sealing member 20 and the liquid injection port 16a.

  As described above, the pipe 38 is used as a temporary sealing member, and at the time of activation and aging treatment, one end of the pipe 38 is connected to the gas treatment device and the activation / aging treatment is performed. If degassing is appropriately performed, distortion of the case 12 due to swelling of the case 12 or the like is unlikely to occur. As a result, the center axis C1 of the liquid injection port 16a and the center axis C2 of the through hole 28 are unlikely to be displaced, so that the time in the main sealing step S20 can be easily shortened.

  When the opening 28b of the through hole 28 is larger than the opening 28a, the sealing member 20 can be easily inserted into the through hole 28. In this case, in the form in which the through hole 28 has a tapered portion as the second hole portion 28B as shown in FIG. 5, the sealing member 20 is shown by the two-dot chain line in FIG. As shown, since it is easy to guide toward the liquid injection port 16a, the main sealing step S20 becomes easier.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention. The temporary sealing member is not limited to piping as long as the liquid injection port 16a can be temporarily sealed. For example, the temporary sealing member may be a stopper that can be attached to and detached from one of the through hole 28 and the liquid injection port 16a. Even when the temporary sealing member is a plug as illustrated, the temporary sealing member can be removed from the case 12 in the temporary sealing releasing step S18. Thereby, like the case of the piping 38, the temporary sealing member does not remain in the case 12. The second hole 28B may not be formed in the through hole 28, and the diameter of the through hole 28 may be constant along the direction of the central axis C2.

  DESCRIPTION OF SYMBOLS 10 ... Power storage device, 12 ... Case, 14 ... Electrode assembly, 16a ... Liquid injection port, 20 ... Sealing member, 22 ... Power storage structure, 24 ... Sealing jig, 28 ... Through-hole, 28B ... 2nd Hole (tapered portion), 28a ... opening (first opening), 28a ... opening (second opening), 38 ... pipe (temporary sealing member), 40 ... electrolytic solution, C1 ... center axis of liquid inlet , C2: central axis of the through hole.

Claims (2)

A power storage structure having a positive electrode, a negative electrode, and an electrode assembly having a separator disposed therebetween, and a case for housing the electrode assembly, and
A sealing member for sealing an injection port of an electrolytic solution that the case has,
A method of manufacturing a power storage device in which an electrolyte is injected into the case,
Fixing a sealing jig having a through hole for guiding the sealing member to the liquid injection port to the case of the power storage structure such that the through hole communicates with the liquid injection port;
Injecting the electrolytic solution into the case from the liquid injection port, and temporarily sealing the liquid injection port by attaching a temporary sealing member to one of the through hole and the liquid injection port;
Activating the electricity storage structure in which the liquid inlet is temporarily sealed, and performing an aging treatment;
Removing the temporary sealing member from the electricity storage structure subjected to the aging treatment;
The sealing member is attached to the liquid injection port of the case through the through hole of the sealing jig, the liquid injection port is fully sealed with the sealing member, and the sealing jig is removed from the case. Removing step;
A method for manufacturing a power storage device. The through hole has a first opening in contact with the liquid injection port and a second opening opposite to the first opening in the central axis direction of the through hole,
The diameter of the second opening is larger than the diameter of the first opening,
The through-hole has a tapered portion whose diameter decreases from the second opening toward the first opening in the central axis direction.
The manufacturing method of the electrical storage apparatus of Claim 1.

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