JP2010282848A - Sealed battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealed battery having an excellent sealing performance of a terminal extraction hole. <P>SOLUTION: The sealed battery 100 includes: a battery case 20 which houses an electrode body 80; an annular seal member 50 which is installed in a periphery portion surrounding a terminal extraction hole 24 installed in the case 20 and includes a through-hole 52; and an electrode terminal 30 of a rivet-form, having a rivet portion 32 protruding from a pedestal portion 34, wherein the rivet portion 32 penetrates from the inside of the case through a through-hole 52 of the seal member 50 and the terminal extraction hole 24 of the case 20. The rivet portion 32 is caulked so as to compress the seal member 50 in the terminal axis direction, and the angle θ made of the upper end face 38 of the caulked portion and a plane 98 perpendicular to the terminal axis direction is in a range of 2°-15°. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sealed battery such as a lithium ion battery, and more particularly to a sealed battery having a structure in which a terminal lead hole provided in a battery case is sealed with an annular seal member.

  In recent years, lithium ion batteries and other sealed batteries (typically secondary batteries) have become increasingly important as power sources for vehicles or power sources for personal computers, portable terminals, and the like. In particular, a lithium ion battery that is lightweight and obtains a high energy density is expected to be preferably used as a high-output power source mounted on a vehicle. Patent document 1 is mentioned as a prior art document regarding this kind of sealed battery.

JP 2008-192552 A

  As one typical configuration of a sealed battery, an electrode body and an electrolyte (typically a nonaqueous electrolyte) are accommodated in a battery case (exterior container), and an electrode terminal (at least one of a positive electrode terminal and a negative electrode terminal) is provided. The structure which penetrated the terminal extraction hole provided in the said case and was pulled out from the inside of this case is mentioned. The extraction hole is typically sealed by an annular seal member interposed between a case wall surface surrounding the opening of the extraction hole and the electrode terminal (for example, Patent Document 1).

  As one of this type of seal structure, the seal structure shown in FIG. 16 has been studied. In the example of FIG. 16, the rivet portion 234 of the electrode terminal 230 is passed through the terminal lead hole 212 of the case 210, and the seal member 220 is disposed between the case 210 and the electrode terminal (base portion 232). Then, as shown in FIG. 17, the rivet portion 234 is pressed in the terminal axis direction using a caulking jig 240 and caulked to thereby seal the seal member 220 between the case 210 and the electrode terminal (base portion 232). Compress. Thereby, the clearance gap between the case 210 and the electrode terminal (base part 232) is closed, and the sealing property of the terminal extraction hole 212 is ensured.

  However, in the structure shown in FIG. 17, when the member 220 is compressed by caulking the rivet portion 234, the tip (outer surface) 237 of the rivet portion 234 escapes to the outer diameter side, so the load on the outer peripheral side is bi-directional ( That is, it is dispersed in the compression direction of the seal member 220 and the diameter expansion direction of the rivet portion 234. Therefore, a compressive load difference occurs between the inside and outside of the seal member 220, and the inner peripheral side 224 may be overcompressed as compared with the outer peripheral side 226 as shown in the graph of FIG. Such a variation in the compression dimension causes the sealing member to be easily cracked by an excessive load when the compression ratio is large, and conversely, when the compression ratio is small, the amount of compression is insufficient and the sealing performance is deteriorated. It becomes a factor that occurs.

  This invention is made | formed in view of this point, The main objective is to provide the sealed battery with favorable sealing performance of a terminal extraction hole. Another object is to provide a method for manufacturing a sealed battery having such performance.

  A sealed battery provided by the present invention includes a battery case that accommodates an electrode body and an electrolyte, an annular sealing member that is disposed at a peripheral portion of a terminal lead hole provided in the case, and that has a through hole, and a pedestal portion A rivet-shaped electrode terminal having a rivet portion projecting from the electrode, the rivet portion being provided so as to penetrate the through hole of the seal member and the terminal lead-out hole of the case from the inside or outside of the case With. The rivet portion is caulked so as to compress the seal member in the terminal axis direction, and the upper end surface of the caulked portion (typically the surface pressed by the pad of the caulking jig during caulking) And a plane perpendicular to the terminal axis direction is in a range of 2 ° to 15 °.

  Moreover, this invention provides the manufacturing method of the sealed battery which has the said structure. That is, a battery case containing an electrode body and an electrolyte, a rivet having an annular seal member having a through hole disposed at a peripheral portion of a terminal lead hole provided in the case, and a rivet portion protruding from a pedestal portion It is a manufacturing method of a sealed battery provided with a shaped electrode terminal. In this method, the step of arranging the rivet portion of the electrode terminal so as to penetrate the through hole of the seal member and the terminal lead-out hole of the case from the inside or outside of the case, and the arranged rivet portion to the seal member And the upper end surface of the caulked portion (typically the surface pressed by the pad of the caulking jig during caulking) with respect to the plane perpendicular to the terminal axis direction. And caulking to tilt at an angle of 2 ° to 15 °.

  In this specification, when defining the vertical direction, in the axial direction of the rivet terminal fixed to the battery case, the side where the rivet portion is located is defined as the upward direction, and the side where the pedestal portion is defined as the downward direction. . Further, in this specification, the “battery” is a term indicating a general power storage device capable of taking out electric energy, and is a concept including a primary battery and a secondary battery. In the present specification, the “secondary battery” is a concept including so-called storage batteries such as lithium ion batteries, metal lithium secondary batteries, nickel metal hydride batteries, nickel cadmium batteries, and power storage elements such as electric double layer capacitors. . The technology disclosed herein is typically applied to a secondary battery and its manufacture.

  According to the configuration of the present invention, the rivet portion is caulked inward in the radial direction by caulking the rivet portion so that the upper end surface of the caulking portion of the rivet portion is inclined at a predetermined angle with respect to a plane perpendicular to the terminal axis direction. Therefore, the dispersion of the load in the diameter increasing direction (radially outward) of the rivet portion can be suppressed. As a result, the caulking load can be applied evenly to the seal member (with no difference in compressive load depending on the location), and the seal member can be compressed to a uniform thickness. Therefore, the case and the rivet terminal (pedestal portion) can be properly adhered with the seal member interposed therebetween, and the gap between the case and the rivet terminal can be closed. That is, according to the present invention, it is possible to provide a sealed battery having excellent quality stability, in which the sealing performance of the terminal lead hole is good, no liquid leakage occurs.

  Any sealed battery (for example, a lithium ion battery) disclosed herein can be suitably used as a battery (may be a battery used in the form of an assembled battery) mounted on a vehicle. Therefore, according to the present invention, a vehicle (for example, an automobile) including a sealed battery manufactured by any of the methods disclosed herein is provided.

It is sectional drawing which shows typically the principal part cross section of the battery which concerns on one Embodiment. It is sectional drawing which shows the manufacturing process of the conventional battery typically. It is sectional drawing which shows typically the manufacture process of the battery which concerns on one Embodiment. It is a perspective view which shows typically the structure of the battery which concerns on one Embodiment. FIG. 5 is a cross-sectional view schematically showing a cross section taken along line VV in FIG. 4. It is a typical side view which shows the electrode body and rivet terminal of the battery which concern on one Embodiment. It is sectional drawing which shows typically the manufacture process of the battery which concerns on one Embodiment. It is sectional drawing which shows typically the manufacture process of the battery which concerns on one Embodiment. It is sectional drawing which shows typically the manufacture process of the battery which concerns on one Embodiment. It is sectional drawing which shows typically the manufacture process of the battery which concerns on one Embodiment. It is sectional drawing which shows typically the principal part cross section of the battery which concerns on an Example. It is a graph which shows the displacement by the measurement position of a compressibility (Example). It is sectional drawing which shows typically the principal part cross section of the battery which concerns on a comparative example. It is a graph which shows the displacement by the measurement position of a compressibility (comparative example). It is a side view which shows typically the vehicle (automobile) provided with the battery which concerns on this invention. It is sectional drawing which shows the manufacturing process of the conventional battery typically. It is sectional drawing which shows the manufacturing process of the conventional battery typically.

  Several preferred embodiments of the present invention are described below. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field.

  Although not intended to be particularly limited, in the following, a wound electrode body (wound electrode body) and a non-aqueous liquid electrolyte (electrolyte solution) are accommodated in a flat rectangular (box-shaped) case. The present invention will be described in detail by taking as an example the case of manufacturing a sealed lithium ion battery of the embodiment. Moreover, in the following drawings, the same code | symbol is attached | subjected to the member and site | part which show | plays the same effect | action, and the overlapping description may be abbreviate | omitted or simplified.

  In FIG. 1, the principal part cross section of the sealed battery 100 which concerns on this embodiment is shown. As shown in FIG. 1, the sealed battery 100 includes a battery case 20, an annular seal member 50, and electrode terminals 30. A gasket 70 and an external terminal 40 are provided.

  The battery case 20 is a case that accommodates the electrode body 80 together with the electrolytic solution, and the terminal lead hole 22 is provided in a part thereof. The terminal lead hole 22 is a lead hole for pulling out the electrode terminal 30 from the inside of the case to the outside, and is provided so as to penetrate the front surface and the back surface of the case 20.

  An annular seal member 50 is attached to the peripheral portion surrounding the terminal lead hole 22. The seal member 50 is made of an elastic material (here, EPDM rubber) that is compressible in the terminal axis direction. The seal member 50 has a through hole 52 at a position corresponding to the terminal lead hole 22 of the case 20. The through hole 52 has an inner diameter large enough to fit the rivet portion 32 of the electrode terminal 30.

  The electrode terminal 30 is a rivet-shaped electrode terminal (hereinafter also referred to as “rivet terminal”), and includes a pedestal portion 34 and a rivet portion 32 protruding from the pedestal portion 34. The pedestal portion 34 is a plate-like member that spreads outward from the outer shape of the extraction hole 22 of the case 20, and a current collector 36 is attached to the lower surface thereof. The current collector 36 is electrically connected to the positive electrode or the negative electrode of the electrode body 80. Here, the pedestal 34 and the current collector 36 are integrally formed, but the pedestal 34 and the current collector 36 may be separated.

  The rivet portion 32 is disposed so as to extend substantially vertically from the upper surface of the pedestal portion 34 to the outside of the case. The rivet portion 32 is disposed so as to penetrate the through hole 52 of the seal member 50 and the terminal lead hole 22 of the case 20 from the inside of the case. The rivet portion 32 is caulked by radially expanding the tip of the rivet portion 32 and pushing the tip of the rivet portion 32 on the upper surface of the external member 40. A two-dot chain line in FIG. 1 represents the rivet portion 33 before caulking. Thus, the rivet terminal 30 and the external terminal 40 are fixed by caulking the tip of the rivet portion 32 to the upper surface of the external member 40. At that time, the seal member 50, the case 20, the gasket 70, and the external terminal 40 are sandwiched and pressed between the caulking portion of the rivet portion 33 and the pedestal portion 34, so that the seal member 50 is moved in the terminal axis direction. The case 20 and the pedestal 34 are in close contact with each other with the seal member 50 interposed therebetween. As a result, a sealing property between the case 20 and the rivet terminal 30 is ensured.

  Here, in this embodiment, when the rivet portion 32 is caulked and the seal member 50 is compressed, the upper end surface 38 of the caulked portion is an angle of 2 ° to 15 ° with respect to the plane 98 perpendicular to the terminal axis direction. One of the features is that it is caulked so as to tilt. That is, an angle formed by the upper end surface 38 of the caulked portion and a plane 98 perpendicular to the terminal axis direction (hereinafter also referred to as “caulking angle”) is in the range of 2 ° to 15 ° (this embodiment) In the form, θ = 5 °).

  FIG. 2 shows a manufacturing process diagram of a conventional caulking structure, and FIG. 3 shows a manufacturing process diagram of the caulking structure of this embodiment.

  In the conventional structure of FIG. 2, by pressing the caulking jig 95 downward in the terminal axis direction, the upper end surface 38 of the caulking portion is flattened (that is, θ = 0 °). The tip was caulked. However, when pressing is performed so that the upper end surface 38 becomes flat in this way, the tip (outer surface) 37 of the rivet portion 32 swells to the outer diameter side and escapes, so the load on the outer peripheral side is bi-directional (that is, the seal member). 50 compression direction and the diameter-expanding direction of the rivet portion 32). For this reason, a difference in compressive load occurs between the inside and outside of the seal member 50, and the inner peripheral side 56 may be overcompressed as compared to the outer peripheral side 54 (typically, compression is performed so that the central portion of the seal member 50 sinks). It tends to be)

  On the other hand, in this embodiment, as shown in FIG. 3, the upper end surface of the caulked portion is pressed by inclining the pad 96 of the caulking jig by an angle θ with respect to the machining axis (terminal axis direction) and pressing downward. The tip of the rivet portion 32 is caulked so that 38 is inclined at an angle of 2 ° to 15 ° with respect to a plane 98 perpendicular to the terminal axis direction. By caulking the tip of the rivet portion 32 so as to incline at the caulking angle θ in this way, an inward load in the radial direction is applied to the caulked portion, so that the rivet portion 32 expands in the diameter direction (radially outward). ) Can be prevented from dispersing the load. As a result, the caulking load can be applied evenly to the seal member (with no difference in compressive load depending on the location), and the seal member can be compressed to a uniform thickness. Therefore, according to the present embodiment, the case 20 and the rivet terminal (the pedestal portion 34) can be appropriately brought into close contact with the seal member 50 interposed therebetween, and the gap between the case 20 and the rivet terminal 30 can be closed. it can. That is, according to the present embodiment, it is possible to provide a sealed battery 100 having excellent quality stability, in which the sealing performance of the terminal lead hole 24 is good, and no liquid leakage occurs.

  In consideration of the above action, the caulking angle θ is preferably in the range of 2 ° to 15 °. If it is smaller than this range, the effect of suppressing the dispersion of the compressive load may not be sufficiently obtained. On the other hand, if it is larger than this range, the load applied radially inward may be too great and the load difference between the inside and outside may be reversed (that is, the outer peripheral side 54 is overcompressed compared to the inner peripheral side 56). . Therefore, the range of the caulking angle θ is about 2 ° to 15 °, preferably about 3 ° to 10 °, more preferably about 3 ° to 7 °, and usually 5 ° ± 2 °. It is good to adjust so that it becomes.

  The caulking process with such an angle θ can be performed using, for example, a rotary caulking machine having a rotating head 96 as shown in FIG. In this case, the rotary head 96 is tilted by an angle θ with respect to the machining center axis (axis line of the rivet portion 32) and rotated around the machining center axis to cause precession. By pushing the rotary head 96 into the tip of the rivet portion 32 in this state, it is possible to perform crimping with an angle θ. The caulking angle θ may be adjusted by appropriately adjusting the inclination angle of the rotary head 96 with respect to the processing center axis.

  Hereinafter, the case where the positive electrode terminal 10 and the negative electrode terminal 110 are attached to the lid 22 of the battery case using the rivet terminal 30 described above will be described with reference to FIGS. 4 and 5. Here, for the sake of convenience, the outer surface of the lid 22 will be described as an upper side, but the posture of the battery 100 is not limited.

  As shown in FIGS. 4 and 5, the lithium ion battery 100 manufactured according to the present example includes a predetermined battery constituent material (a sheet-like electrode in which each positive and negative electrode current collector holds a positive and negative electrode active material). , A separator, etc.) are housed in a battery case 20 having a shape that can accommodate the electrode body (here, a flat rectangular parallelepiped shape, that is, a square shape) together with an appropriate electrolyte (not shown). It has a configuration.

  The case 20 includes a box-shaped (ie, bottomed rectangular tube-shaped) case main body 21 having an opening at one end, and a lid 22 attached to the opening to close the opening. The lid 22 is formed in a rectangular shape that matches the opening shape of the main body 21. The positive electrode terminal 10 and the negative electrode terminal 110 connected to the wound electrode body 80 are drawn out to the outside of the case 20 through the terminal lead holes 24 provided at one end and the other end in the longitudinal direction. As a material constituting the case 20, the same materials as those used in a general lithium ion battery can be appropriately used, and there is no particular limitation. From the viewpoint of heat dissipation and the like, a metal (for example, aluminum) case 20 can be preferably used. The case 20 (the main body 21 and the lid body 22) of the present embodiment is made of aluminum.

  The positive electrode terminal 10 includes an external terminal 40 and a rivet-shaped positive electrode terminal (rivet terminal) 30 that fixes the external terminal 40 to the lid body 22. The rivet terminal 30 includes a pedestal portion 34 that extends outward from the outer shape of the terminal lead hole 24, and a rivet portion 32 that protrudes from the pedestal portion 34. The external terminal 40 and the rivet terminal 30 are connected (fastened) by caulking the rivet portion 32 of the rivet terminal 30 through the rivet hole 42 of the external terminal 40. As shown in FIG. 5, the caulking process is performed with the seal member 50, the lid body 22, and the outer insulating member 70 sandwiched between the base portion 34 of the rivet terminal 30 and the external terminal 40 (that is, between the fastened portions). Is called. In FIG. 5, the shape of the rivet portion 33 before caulking is shown by a two-dot chain line. By this caulking process, the positive electrode terminal 10 is fixed to the lid body 22, and the seal member 50 is formed between the inner wall surface 23 of the lid body 22 surrounding the terminal lead hole 24 and the pedestal portion 34 of the rivet terminal 30 facing the portion. Is compressed to seal the extraction hole 24.

  The external terminal 40 is formed by bending or punching a plate-shaped (strip-shaped) material, and has a first connecting portion 47 provided with a rivet hole 42 and a stepped shape following the first connecting portion 47. And a second connecting portion 49 formed. For example, as shown in FIG. 4, the second connection portion 49 uses a bolt 64 and a nut 66 to connect (fix) a connection member 62 for external connection (may be a terminal of another battery, an external circuit, etc.). Configured to get.

  The outer shape of the negative electrode terminal 110 and the lead-out structure thereof are the same as those on the positive electrode terminal side. That is, the negative electrode terminal 140 includes a rivet terminal 130 and an external terminal 140, and the both terminal members 130 and 140 are connected by caulking the rivet portion 132 of the rivet terminal 130 to the external member 140. The caulking is performed by sandwiching the seal member 50, the lid 22 and the outer insulating member 70 between the terminal members 130 and 140, as in the positive electrode side. The external terminal 140 is formed in a step shape having a first connection portion 147 and a second connection portion 149, and the second connection portion 149 is configured to be able to connect (fix) a connection member 162 for external connection. ing.

  As shown in FIG. 6, the wound electrode body 80 includes a long sheet-like positive electrode (positive electrode sheet) 82 and a negative electrode (negative electrode sheet) 84 in total, like the wound electrode body of a normal lithium ion battery. It can be manufactured by laminating together with a long sheet-like separator (separator sheet) 86 and winding it in the longitudinal direction, and crushing the obtained winding body from the side direction and abating it. The positive electrode sheet 82 and the negative electrode sheet 84 are slightly shifted in the width direction, and are stacked so that one end in the width direction of the separator sheet 86 and one end in the width direction of the sheets 82 and 84 protrude from each other. It has been turned. As a result, one end in the width direction of the positive electrode sheet 82 is at one end in the winding axis direction of the wound electrode body 80 and the wound core portion 81 (that is, the positive electrode sheet 82, the negative electrode sheet 84, and the separator sheet). 82A that protrudes outward from the portion 86 is tightly wound (a portion where the positive electrode sheet protrudes) 82A, and a portion where one end in the width direction of the negative electrode sheet 84 protrudes outward from the wound core portion 81 (negative electrode) 84A is formed respectively.

The material and the member constituting the wound electrode body 80 may be the same as the electrode body provided in the conventional lithium ion battery, and are not particularly limited. For example, the positive electrode sheet 82 may have a configuration in which a positive electrode active material layer is formed on a long positive electrode current collector (for example, an aluminum foil). As the positive electrode active material used for forming this positive electrode active material layer, one or two or more materials conventionally used in lithium ion batteries can be used without particular limitation. Preferable examples include lithium transition metal oxides such as LiNiO ₂ , LiCoO ₂ , and LiMn ₂ O ₄ . The negative electrode sheet 84 may have a configuration in which a negative electrode active material layer is formed on a long negative electrode current collector (for example, copper foil). As the negative electrode active material used for forming this negative electrode active material layer, one or two or more materials conventionally used in lithium ion batteries can be used without particular limitation. Preferable examples include carbon-based materials such as graphite carbon and amorphous carbon, lithium transition metal oxides, lithium transition metal nitrides, and the like. Preferable examples of the separator sheet include those made of a porous polyolefin resin. In this example, aluminum foil is used as the positive electrode sheet 82, LiNiO ₂ is used as the positive electrode active material, copper foil is used as the negative electrode sheet 84, and natural graphite is used as the negative electrode active material.

  As shown in FIG. 6, one end of a rivet terminal 30 constituting the positive electrode terminal 10 is connected to the protruding portion 82A of the positive electrode sheet, for example, by laser welding. The rivet terminal 30 is formed following the plate-shaped (band-shaped) pedestal portion 34 extending from the one end to the radially outer side of the wound electrode body 0 and the other end of the pedestal portion 34, and along the outer periphery of the electrode body 80. A plate-shaped (band-shaped) current collector 36 extending in the axial direction (substantially perpendicular to the direction in which the pedestal extends), and a rivet portion 32 extending substantially perpendicularly from the plate surface of the pedestal 34 to the outside of the battery. Prepare. The constituent material of the rivet terminal 30 is preferably a metal material having good conductivity, and typically aluminum is used. The rivet terminal 30 of this embodiment is made of aluminum.

  On the other hand, one end of a rivet terminal 130 constituting the negative electrode terminal 110 is connected to the negative electrode sheet protruding portion 34A by, for example, resistance welding. The rivet terminal 130 includes a pedestal part 134, a current collecting part 136, and a rivet part 132 that are formed in the same manner as the rivet terminal 30 on the positive electrode side. As a constituent material of the rivet terminal 130, a metal material having good conductivity is preferable, and copper is typically used. The rivet terminal 130 of this embodiment is made of copper.

  An embodiment for producing a lithium ion battery 100 having such a configuration will be described.

  First, the lid body 22 provided with the terminal lead hole 24 is prepared as described above, and the rivet terminals 30 and 130 and the external terminals 40 and 140 are connected through the lead hole 24 to form the electrode terminals 10 and 110. To do. As a result, the positive electrode terminal 10 and the negative electrode terminal 110 are attached to the lid body 22 (terminal lead hole 24). As described above, since the positive electrode terminal 10 and the negative electrode terminal 110 have the same external shape and lead-out structure, the above connection (caulking process) process will be specifically described taking the positive electrode terminal 10 side as an example.

  As shown in FIG. 7, a rivet portion 32 of a rivet terminal 30 constituting the positive electrode terminal 10 is passed through a through hole 52 of a donut disc-like (perforated disc-like) seal member 50, and the seal member 50 is inserted into the rivet portion. 32 on the pedestal 34 around the periphery. Further, an inner insulating member (gasket) 78 is disposed so as to be engaged with the outer edge of the current collector 36. The rivet portion 32 of the rivet terminal 30 in which the seal member 50 and the inner insulating member 78 are disposed is inserted through the terminal lead-out hole 24 of the lid body 22 from the inside of the case. A cylindrical portion 72 of the outer insulating member 70 is inserted from the outside of the case into the extraction hole 24, thereby preventing direct contact between the wall surface of the extraction hole 24 and the outer periphery of the rivet portion 32. The outer insulating member 70 includes a dish portion 74 that is formed following the cylindrical portion 72 and extends along the outer surface of the lid body 22. The first connection part 47 of the external terminal 40 is arranged in accordance with the depression of the dish part 74. The first connection portion 47 has a rivet hole 42 at a position corresponding to the terminal lead hole 24. The outer opening of the rivet hole 42 is formed in a tapered shape that gradually increases in diameter toward the outer side. A rivet portion 32 protrudes outside the case through the rivet hole 42.

  As a constituent material of the external terminal 40, a metal material having good conductivity (aluminum, copper, steel, stainless steel (SUS), etc.) can be preferably used. The external terminal 40 of this embodiment is made of SUS. Note that the same material as that of the positive electrode side can be preferably used for the external terminal 140 on the negative electrode side (see FIG. 4). The external terminal 140 on the negative electrode side in this embodiment is made of SUS.

  The constituent material of the sealing member 50 is not particularly limited as long as it can exhibit a desired sealing property (for example, performance of preventing moisture intrusion). An elastic material having good resistance to the electrolytic solution used in the battery is preferable. For example, fluorine rubbers such as ethylene-propylene rubber (EPM), ethylene-propylene-diene copolymer rubber (EPDM), fluorine rubber (for example, vinylidene fluoride (FKM), tetrafluoroethylene-propylene (FEPM), etc.) ), Elastic materials having high resistance to organic solvents, such as butyl rubber, can be preferably used. Further, a sealing member made of an elastic material such as nitrile rubber (NBR), acrylic rubber (ACM), or silicone rubber may be used. The seal member 50 of this embodiment is made of EPDM, for example.

  As a constituent material of the insulating members 70 and 78, various polymer materials exhibiting resistance to the electrolyte to be used can be appropriately selected and used. For example, polymer materials such as polyolefin resins such as polypropylene (PP) and polyethylene (PE); fluorine resins such as perfluoroalkoxyalkane (PFA) and polytetrafluoroethylene (PTFE); can be preferably used. Further, a polymer material such as polyphenylene sulfide resin (PPS), polyimide resin, polyamideimide resin, polyether ether ketone resin (PEEK), or polyether sulfone resin (PES) may be used. The constituent material of the inner insulating member 78 and the constituent material of the outer insulating member 70 may be the same or different. The insulating members 70 and 78 of this embodiment are both made of PPS.

  The rivet terminal 30 is disposed on a caulking base 92 that supports the base portion 34 of the rivet terminal 30 from below. A pressing jig 94 is disposed on the first connection portion 47 of the external terminal 40. The pressing jig 94 applies a predetermined pressing force to the external terminal 40 (first connection portion 47) in order to prevent warpage of the external terminal 40 (first connection portion 47).

  After each member is arranged as described above, the tip of the rivet portion 32 protruding from the rivet hole 42 of the external terminal 40 is then crimped. First, as shown in FIG. 7, a caulking jig 90 having a conical tip is pressed toward the inner hole 39 of the rivet portion 32. By pressing the caulking jig 90, as shown in FIG. 8, the tip of the rivet portion 32 is pushed outward and expanded radially. In this embodiment, the tip of the rivet portion 32 is hollow (for example, cylindrical). For this reason, when the tip of the rivet portion 32 is pushed wide, the inner surface 39 of the cylindrical inner hole is expanded and exposed to form at least a part of the upper end surface 38 of the caulking portion.

  Next, the tip of the rivet portion 32 is further expanded using a rotary caulking machine having a rotary head 96 as shown in FIG. In this case, the rotary head 96 is precessed while being tilted by an angle θ with respect to the processing center axis (the axis of the rivet portion 32), and the rotary head 96 is pushed into the tip of the rivet portion 32 in this state. The caulking angle θ may be adjusted by appropriately adjusting the inclination angle of the rotary head 96 with respect to the processing center axis. The caulking process of the rivet portion 32 is completed by pushing the tip of the rivet portion 32 onto the first connection portion 47 of the external terminal 40 by the pressing force of the rotary head 96.

  In the caulking step, the seal member 50, the lid 22, the outer insulating member 70, and the external terminal 40 are sandwiched and pressed between the caulking portion of the rivet portion 32 and the pedestal portion 34, whereby the seal member 50 is pressed. Is compressed in the terminal axis direction. At this time, since the upper end surface 38 of the caulking portion of the rivet portion 32 is caulked so as to be inclined at an angle of 2 ° to 15 ° with respect to the plane 98 perpendicular to the terminal axis direction, the caulking load is evenly applied to the seal member 50. The sealing member 50 can be compressed uniformly. Thus, the lid body 22 and the pedestal portion 34 can be appropriately brought into close contact with the seal member 50 interposed therebetween, and the gap between the lid body 22 and the rivet terminal 30 can be sealed.

  Further, the positive electrode terminal 10 and the negative electrode terminal 110 can be attached to the lid body 22 by the caulking process. The negative electrode terminal 110 can be attached by caulking the negative side rivet portion 132 in the same manner as the positive side. The order of attaching the positive electrode terminal 10 and the negative electrode terminal 110 is not particularly limited.

  In this embodiment, the caulking step is performed in two steps: a first caulking step (FIG. 8) for appropriately deforming the tip of the rivet portion 32 and a second caulking step (FIG. 10) for further expanding the diameter. Thereby, caulking can be performed stably. You may perform in one process using the crimping jig | tool of the shape which combined the crimping jig | tool 90 (FIG. 8) and the crimping jig | tool 96 (FIG. 10).

  Then, for example, the lithium ion battery 100 is constructed as follows. That is, the rivet terminals 30 and 130 of the positive electrode terminal 10 and the negative electrode terminal 110 are joined to the protruding portions 82A and 84A of the positive electrode sheet and the negative electrode sheet formed at both ends in the axial direction of the wound electrode body 80 having the above configuration (for example, Welding) (see FIG. 6). As a result, the electrode body 80 and the lid body 22 are coupled. Then, the electrode body 80 coupled to the lid body 22 is placed inside the opening portion of the case body 21 so that the lid body 22 is covered with the opening body, and the joint between the lid body 22 and the case body 21 is, for example, a laser. Seal by welding.

Next, an electrolytic solution is injected into the case 20 from an electrolytic solution injection hole (not shown). As the electrolytic solution, the same non-aqueous electrolytic solution conventionally used for lithium ion batteries can be used without particular limitation. Such a nonaqueous electrolytic solution typically has a composition in which a supporting salt is contained in a suitable nonaqueous solvent. As the non-aqueous solvent, for example, one or more selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and the like can be used. Examples of the supporting salt include LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) _{3 and the} like. Lithium salts can be used. In the lithium ion battery according to the present embodiment, an electrolytic solution in which LiPF ₆ is contained at a concentration of about 1 mol / liter in a mixed solvent of ethylene carbonate and diethyl carbonate (for example, a mass ratio of 1: 1) is used. Thereafter, the case 20 is sealed by closing the electrolyte injection hole. In this way, the lithium ion battery 100 can be manufactured (constructed).

  Next, in order to confirm that the seal member 50 can be uniformly compressed by adopting the configuration of the present embodiment, the following experiment was performed as an example.

  That is, as shown in FIG. 11, a seal member 50 made of EPDM rubber was used, and the seal member 50 was compressed between the lid 22 and the pedestal portion 34. The sealing member 50 was compressed by caulking the tip of the rivet portion 32 with a rotary caulking machine. As the caulking conditions, pressing was performed at a load of 1000 N so that the caulking angle θ = 5 °. The seal member 50 after pressing was taken out and cut in cross section, and the thickness dimension after pressing was measured. And the compression rate was computed from the displacement of the thickness dimension before and behind a press. The compression rate was calculated at four points of measurement positions A to D in FIG. The result is shown in FIG.

  As a comparative example, as shown in FIG. 13, the seal member 50 was compressed by caulking the rivet terminal without providing the caulking angle θ. The compression of the sealing member 50 was performed using a general press machine. As the caulking conditions, pressing was performed at a load of 5000 N so that the caulking portion was flat (caulking angle θ = 0 °). The seal member 50 after pressing was taken out and cut in cross section, and the thickness dimension after pressing was measured. And the compression rate was computed from the displacement of the thickness dimension before and behind a press. The compression rate was calculated at four points of measurement positions A to D in FIG. The result is shown in FIG.

  As shown in FIGS. 12 and 14, in the example (FIG. 12) in which the rivet terminal is caulked with a caulking angle θ = 5 °, the difference in compression rate at each measurement position A to D is about 4%. On the other hand, in the comparative example (FIG. 14) in which the rivet terminal was caulked without providing the caulking angle θ, the difference in compression rate at each measurement position A to D was as large as about 7%. From this, it was confirmed that the thickness of the seal member can be more evenly compressed (without variation in the compression ratio) by caulking the rivet terminal with a caulking angle θ = 5 °.

  As mentioned above, although this invention was demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible.

  For example, the embodiment disclosed herein can be preferably applied to the manufacture of the battery 100 in a form in which the electrode terminals 10 and 110 are pulled out from the upper end surface of the flat rectangular case 20 as in the above embodiment. The application object of the invention is not limited to the battery of such a form, and can be preferably applied to the manufacture of a battery having a form in which, for example, the electrode terminal is drawn from the end face of the cylindrical case.

  Moreover, in this embodiment, although the rivet part 32 of the rivet terminal 30 is attached from the inside of the case, the present invention is not limited to this, and the rivet part 32 may be attached from the outside of the case. In this case, the rivet terminal 30 may be integrated with the external terminal 40, and an internal terminal connected to the electrode body 80 inside the case may be separately prepared. In this case, the rivet terminal 30 can be used for connecting and fixing the internal terminal and the external terminal 40. In addition, when attaching the rivet part 32 from the case outer side, in the terminal axial direction, the side where the rivet part 32 is located (the case inner side) is the upward direction, and the side where the pedestal part 34 is located is the downward direction.

  A sealed battery (typically a secondary battery, for example, a lithium ion battery) manufactured by applying the method according to the present invention is suitably used as a power source for a motor (electric motor) mounted on a vehicle such as an automobile. Can do. Therefore, the present invention, for example, as schematically shown in FIG. 15, is a vehicle (typically, which may be in the form of an assembled battery formed by connecting a plurality of such batteries 100 in series) as a power source. In particular, an automobile (in particular, a car equipped with an electric motor such as a hybrid car or an electric car) 1 is provided.

DESCRIPTION OF SYMBOLS 1 Vehicle 10 Positive electrode terminal 20 Battery case 21 Case main body 22 Cover body 23 Inner wall surface 24 Terminal extraction hole 30,130 Rivet terminal 32 Rivet part 33 Rivet part (before caulking)
34 pedestal portion 36 current collecting portion 37 outer side surface 38 upper end surface 39 inner hole 40, 140 external terminal 42 rivet hole 47 first connection portion 49 second connection portion 50 seal member 52 through hole 54 outer peripheral side 56 inner peripheral side 62 connection member 64 Bolt 66 Nut 70 Outer insulating member 72 Tube portion 74 Plate portion 78 Inner insulating member 80 Winding electrode body 81 Winding core portion 82 Positive electrode sheet 84 Negative electrode sheet 86 Separator sheet 90 Caulking jig 94 Pressing jig 96 Rotating head 98 Plane 100 Sealed Battery 210 Case 212 Terminal Lead-Out Hole 220 Seal Member 224 Inner Side 226 Outer Side 230 Electrode Terminal 232 Base Part 234 Rivet Part

Claims (3)

A battery case containing the electrode body and the electrolyte;
An annular sealing member attached to a peripheral portion surrounding the terminal lead hole provided in the case and having a through hole;
A rivet-shaped electrode terminal having a rivet portion projecting from a pedestal portion, the rivet portion being provided so as to penetrate the through hole of the seal member and the terminal lead hole of the case from the inside or the outside of the case With electrode terminals,
The rivet portion is caulked so as to compress the seal member in the terminal axis direction, and an angle formed by an upper end surface of the caulked portion and a plane perpendicular to the terminal axis direction is within a range of 2 ° to 15 °. A sealed battery, characterized in that A battery case containing the electrode body and the electrolyte;
An annular sealing member attached to a peripheral portion surrounding the terminal lead hole provided in the case and having a through hole;
A method of manufacturing a sealed battery comprising a rivet-shaped electrode terminal having a rivet portion projecting from a pedestal portion,
Arranging the rivet part so as to penetrate the through hole of the seal member and the terminal lead hole of the case from the inside or outside of the case;
The arranged rivet portion is caulked so that the seal member is compressed in the terminal axis direction, and the upper end surface of the caulked portion is at an angle of 2 ° to 15 ° with respect to a plane perpendicular to the terminal axis direction. A method of manufacturing a sealed battery, the method including:   A vehicle comprising the sealed battery according to claim 1 or the sealed battery manufactured by the method according to claim 2.

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