JP5754280B2 - Battery and manufacturing method thereof - Google Patents

Description

  The present invention includes a battery case having a through hole communicating with the inside and the outside of the battery case, and an electrode body accommodated in the battery case, and a battery formed by hermetically sealing the through hole of the battery case, and The present invention relates to a battery manufacturing method.

  Conventionally, a battery case provided with a through hole such as a liquid injection hole for injecting an electrolytic solution and an electrode body accommodated in the battery case are hermetically sealed. Batteries are known. And batteries using various structures have been proposed as sealing structures for sealing the through holes. For example, Patent Documents 1 to 4 disclose a sealed battery in which a through hole is sealed with a sealing member having a resin plug portion and a metal lid portion. Here, the resin plug portion is press-fitted into the through hole of the battery case, and the through hole is hermetically sealed by itself. On the other hand, the metal lid part is welded in the form of dots while pressing the resin plug part while covering the resin plug part from the outside of the battery in order to make the sealing with the resin plug part more reliable. Etc., and joined to the battery case.

JP 2009-87659 A JP 2008-41548 A JP 2005-190689 A JP 2001-313022 A

  In the sealed batteries described in Patent Documents 1 to 4, the through hole is sealed with the resin plug part itself. However, since the resin plug portion is made of resin and deteriorates with time, the airtightness between the resin plug portion and the through hole decreases with time. In particular, in-vehicle batteries such as hybrid vehicles and electric vehicles are used over a long period of time, for example, 10 years or more, and there is a concern that the airtightness may decrease due to the deterioration with time.

On the other hand, the metal lid part is joined to the battery case by welding or the like to ensure sealing by the resin plug part.
However, in Patent Document 1 and the like, the metal lid portion is not air-tightly welded to the battery case. Therefore, when the resin plug portion deteriorates with time, the air-tightness is lowered as it is.

In view of this, it is conceivable that the metal lid portion is further airtightly joined to the battery case by, for example, all-around welding so that there is no problem even if the resin stopper portion deteriorates with time and the airtightness is lowered.
However, in such a battery, the resin plug portion is not yet deteriorated immediately after manufacture, and the airtightness is also maintained in the resin plug portion. For this reason, even if there is a sealing failure due to poor bonding between the metal lid and the battery case, the gas lid is sealed by detecting gas leaking from between the metal lid and the battery case. It is not possible to inspect the stop failure.
Therefore, in the battery having such a configuration, the airtightness between the metal lid portion and the battery case cannot be confirmed.
The present invention has been made in view of the current situation, and provides a battery capable of appropriately inspecting the airtightness between a sealing member for sealing a through hole of a battery case and the battery case, and a method for manufacturing the same. For the purpose.

The battery case is made of metal and has a through-hole penetrating the inside and outside of the battery case, the electrode body accommodated in the battery case, the metal case covering the through-hole from the outside, and the battery case Among them, an outer sealing member that is fixed to the peripheral edge of the through hole located at the peripheral edge of the through hole and hermetically seals the through hole, the outer sealing member, and the peripheral edge of the through hole of the battery case An inner sealing member having a rubber-like plug body made of a rubber-like elastic body that is fitted in the through-hole and can be tightly plugged into the through-hole, And a post-recovery release member made of a shape memory material whose shape has been restored to the first shape stored in the memory, wherein the first shape while maintaining the memory of the first shape The second shape, which is different from the shape, is below the shape recovery temperature. When the shape is recovered by raising the temperature to the first shape and the member to be the post-recovery release member is a pre-recovery release member, the rubber plug of the inner sealing member is inserted into the through hole from the outside. The rubber-like plug body is moved by the deformation when the shape of the pre-recovery release member of the second shape is restored to the first shape. In the temporary sealing step of disposing the pre-recovery release member so that the sealing plug of the through-hole by the plug body can be released, and the outer sealing member, the through-hole, the pre-recovery release member, and the inner seal The member is covered from the outside, and the outer sealing member is hermetically fixed to the peripheral edge of the through hole of the battery case, and the pre-recovery release member is heated to recover the shape to the first shape. by causing, by moving the rubber stopper A method for producing a battery and a release step for releasing the sealed in the through hole by the rubber-like stopper.

  By the way, if the through hole is not temporarily sealed before the outer sealing member is fixed to the peripheral portion of the through hole, the electrolyte injected into the battery case adheres to the peripheral portion of the through hole. There is a possibility that the outer peripheral sealing member may not be properly fixed due to dirt attached to the peripheral edge, resulting in a malfunction. However, this battery manufacturing method includes a temporary sealing step in which the through-hole is sealed with an inner sealing member having a rubber-like plug and a fixing step in which the outer sealing member is air-tightly fixed to the peripheral portion of the through-hole. Accordingly, the outer sealing member can be appropriately fixed to the peripheral edge of the through hole of the battery case in a state where the through hole is sealed (temporarily sealed) with the rubber plug of the inner sealing member. In addition, since the sealing plug of the through hole by the rubber plug body of the inner sealing member is released in the subsequent releasing step, the through hole is not sealed by the rubber plug body but is sealed airtight only by the outer sealing member. It will be stopped. For this reason, in the battery manufactured in this way, the airtightness of the through hole by the outer sealing member can be appropriately inspected thereafter (before shipment or at an appropriate timing after shipment).

Note that the pre-recovery release member and the rubber-like plug body are formed by moving the rubber-like plug body as a result of the deformation of the pre-recovery release member from the second shape to the first shape, so that the through-hole of the rubber-like plug body What is necessary is just to comprise the mutual relationship (mechanism) which can cancel | release the sealing plug (temporary sealing) with respect to.
Therefore, both may be configured such that the rubber-like plug body is directly moved by, for example, lifting the rubber-like plug body in the direction of pulling out from the through hole by deformation of the release member before recovery. In this case, the pre-recovery release member and the rubber plug may be configured separately or may be configured as a single unit.
Conversely, another member is interposed between the pre-recovery release member and the rubber plug, and the other member is moved or deformed by deformation of the pre-recovery release member, thereby indirectly connecting the rubber plug. It is good also as a structure moved to. In this case, the pre-recovery release member, the other member, and the rubber plug may be separated from each other, the pre-recovery release member and the other member may be integrated, or another member and the rubber. The plug member may be integrated, or further, the three members may be integrated.

  Examples of the material of the rubber plug include ethylene propylene diene rubber (EPDM), which is a rubber-like elastic body, and resins obtained by mixing polypropylene (PP), which is a thermoplastic resin, with ethylene propylene diene rubber (EPDM).

The pre-recovery release member and the post-recovery release member (hereinafter also referred to simply as “release member” when collectively referred to as both) are made of a shape memory material that recovers its shape by setting it to a shape recovery temperature or higher. Specifically, for example, those composed of a shape memory resin made of polyurethane, polynorbornene or the like can be mentioned. In the shape memory resin, the glass transition temperature corresponds to the shape recovery temperature. As the shape memory resin constituting the release member, it is preferable to select one having a glass transition temperature which is a shape recovery temperature of 30 to 75 ° C. This is because the glass transition temperature is higher than room temperature (20 to 25 ° C.), and thus the shape does not recover at room temperature, while the shape can be recovered easily by raising the temperature to the glass transition temperature or higher.
In addition, examples of the shape memory material constituting the release member include shape memory alloys such as nickel / titanium alloys and iron / manganese / silicon alloys. In the shape memory alloy, the transformation point corresponds to the shape recovery temperature. Even when a release member made of a shape memory alloy is used, it is preferable that the transformation point that is the shape recovery temperature is 30 to 75 ° C. as in the case of the shape memory resin.
In addition to the above-described relationship with the rubber plug and the like, the release member may be configured separately from the peripheral portion of the through hole of the battery case, or may be formed integrally.

  Examples of a method for airtightly fixing the outer sealing member to the periphery of the through hole of the battery case include methods such as welding, brazing (soldering), bonding with an adhesive, and crimping such as winding. It is done.

  Further, in the releasing step, as a method of raising the temperature of the releasing member before recovery to the shape recovery temperature or more, the battery case and the outer sealing are performed by putting the entire battery case (battery) into a constant temperature bath having a predetermined high temperature. A method of raising the temperature of the pre-recovery release member, including the member, to a shape recovery temperature or higher can be mentioned. In addition, the outer sealing member and the battery case in the vicinity thereof are brought into contact with a hot plate or radiated with infrared rays from an infrared heater to warm them intensively, and the pre-recovery release member is raised above the shape recovery temperature. There is also a method of heating.

  Furthermore, in the battery manufacturing method described above, the battery includes an airtight inspection step of inspecting airtightness between the outer sealing member and the peripheral edge of the through hole of the battery case after the releasing step. A manufacturing method is preferable.

  In this battery manufacturing method, since the airtightness between the outer sealing member and the peripheral edge of the through hole of the battery case is inspected after the release step in the manufacturing stage, the airtightness between the outer sealing member and the battery case is checked. Can be manufactured.

  As an inspection method in the airtight inspection process, a method that can inspect the airtightness required between the outer sealing member and the peripheral edge of the through hole of the battery case may be employed. For example, a battery is placed in a vacuum chamber, the inside of the vacuum chamber is decompressed, a hydrogen gas detector is installed in the vicinity of the outer sealing member, and sealing between the outer sealing member and the battery case is insufficient. In some cases, there is a technique for detecting hydrogen gas leaking from the battery case.

  Furthermore, in the battery manufacturing method described above, the pre-recovery release member having the second shape has a cylindrical shape whose inner diameter is larger than the through hole, and the post-recovery having the first shape. The release member has a cylindrical shape whose inner diameter is larger than that of the through hole, and the height thereof is higher than the height of the second shape. The inner sealing member is integrated with the rubber plug. The rubber plate has a form protruding from the center portion inside the peripheral edge portion of the plug forming surface of the metal plate, and the temporary sealing step The cylindrical release member before recovery is arranged in such a form that one end thereof is in contact with the peripheral edge of the through hole of the battery case and the through hole is located inside thereof, and the inside of the release member before recovery and The rubber plug of the inner sealing member is inserted into the through hole, and the through hole is sealed. In addition, the peripheral portion of the plug forming surface of the metal plate is brought into contact with the other end of the pre-recovery release member, and the release step recovers the pre-recovery release member to the first shape. The battery is a step of releasing the sealing plug of the through hole by the rubber plug by moving the metal plate and the rubber plug in the direction of removing the rubber plug from the through hole. It would be better to do it.

In this battery manufacturing method, a cylindrical release member may be arranged on the periphery of the through hole, and the arrangement of the release member is simple.
Further, the inner sealing member has a metal plate integrated with the rubber plug, and when the release member is deformed after recovery, the inner sealing member pushes up the metal plate. Thereby, with a simple structure, the sealing plug of the through hole by the rubber plug of the inner sealing member can be reliably released.

  Furthermore, in the battery manufacturing method described above, the temporary sealing step is a step of sealing the through hole with the rubber plug of the inner sealing member under a reduced pressure that is lower than atmospheric pressure. A method of manufacturing a battery is preferable.

  In this battery manufacturing method, in the temporary sealing step, the through hole is sealed with a rubber plug of the inner sealing member under reduced pressure. Thereby, the pressure-reduced state in a battery case can be maintained after that. For this reason, even if gas is generated in the battery case in the subsequent conditioning (initial charge / discharge) or subsequent use, it is possible to suppress the internal pressure in the battery case from increasing quickly.

  Furthermore, in the battery manufacturing method described above, the through hole is a liquid injection hole for injecting an electrolytic solution into the battery case, and the temporary sealing step is performed through the liquid injection hole. It is preferable to use a method for manufacturing a battery after the liquid injection step of injecting the liquid.

  In this battery manufacturing method, the temporary sealing step is performed after the electrolyte solution is injected, and the electrolyte solution leaks out in the subsequent steps, and the electrolyte solution adheres to the peripheral edge of the through hole. It is possible to prevent a problem that the fixing member cannot be properly fixed.

  Another aspect is a battery case made of metal and having a through-hole penetrating inside and outside of the battery case, an electrode body housed in the battery case, and made of metal, covering the through-hole from the outside, and the battery case An outer sealing member that is firmly attached to a peripheral portion of the through hole located at a peripheral edge of the through hole and hermetically seals the through hole, and a peripheral portion of the through hole of the battery case and the outer sealing member. An inner sealing member having a rubber-like plug body made of a rubber-like elastic body, which is disposed in a sealing space between the outer circumference and can be fitted into the through-hole from the outside to seal the through-hole, and the sealing space And a post-recovery release member made of a shape memory material having a first shape, wherein the rubber plug of the inner sealing member is fitted into the through hole from the outside. The through hole is sealed and the outer sealing member is fixed. In variations of the above recovery after releasing member with the shape recovery of the to the first shape, a battery formed by releasing the sealed in the through hole.

  In this battery, the sealing plug of the through hole by the rubber plug is released by the deformation of the release member after recovery after fixing the outer sealing member. For this reason, the fixing failure of the outer sealing member due to the electrolytic solution or the like adhering to the peripheral edge of the through hole before the outer sealing member is fixed is unlikely to occur. Moreover, since the sealing plug by the rubber plug is released after the outer sealing member is fixed, this battery can appropriately perform the airtightness inspection of the sealing by the outer sealing member.

1 is a longitudinal sectional view showing a lithium ion secondary battery according to Embodiment 1. FIG. It is a longitudinal cross-sectional view of the inner side sealing member which concerns on Embodiment 1 and has a metal plate integrated with the rubber-like stopper. It is a longitudinal cross-sectional view concerning Embodiment 1, (a) Release member before recovery, and (b) Release member after recovery. It is a longitudinal cross-sectional view which concerns on Embodiment 1 and shows the sealing state of the through-hole after a temporary sealing process. It is a longitudinal cross-sectional view which concerns on Embodiment 1 and shows the sealing state of the through-hole after the adhering process. It is a longitudinal cross-sectional view which concerns on the modification 1 and shows the sealing state of the through-hole after a cancellation | release process. FIG. 6 is an explanatory diagram showing a hybrid vehicle according to a second embodiment. It is explanatory drawing which shows the hammer drill which concerns on Embodiment 3. FIG.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a lithium ion secondary battery (sealed battery) 1 (hereinafter also simply referred to as battery 1) according to the first embodiment. Moreover, FIGS. 4-6 shows the sealing structure of the through-hole 12H (injection hole) (including the state in a manufacturing process). In the present specification, the upper side in FIG. 1 and FIGS. 4 to 6 is described as the upper side UW of the battery 1, and the lower side is described as the lower side DW of the battery 1.

  The battery 1 is a prismatic battery mounted on a vehicle such as a hybrid vehicle or an electric vehicle, or a battery-powered device such as a hammer drill. The battery 1 includes a rectangular parallelepiped battery case 10, a wound electrode body 20 accommodated in the battery case 10, a positive terminal 40 and a negative terminal 41 supported by the battery case 10 ( (See FIG. 1). Further, a non-aqueous electrolyte solution 17 is held in the battery case 10.

  Of these, the battery case 10 is made of metal (aluminum in the first embodiment). The battery case 10 includes a rectangular parallelepiped box-shaped case main body member 11 in which only the upper UW is opened, and a rectangular plate-shaped case cover member 12 welded in a form for closing the opening 11H of the case main body member 11. ing.

  The case lid member 12 is provided with a safety valve 15 that is broken when the internal pressure of the battery case 10 reaches a predetermined pressure. Further, the case lid member 12 is provided with a through hole 12H (liquid injection hole) that communicates the inside and outside of the battery case 10. The through hole 12H is hermetically sealed by the outer sealing member 50.

  Further, the case lid member 12 is fixedly provided with a positive electrode terminal 40 and a negative electrode terminal 41 each constituted by an extended terminal member 42 and a bolt 43 via an insulating member 44 made of resin. In the battery case 10, the positive electrode terminal 40 is connected to the positive electrode plate 21 (the positive electrode current collector 21 m) of the electrode body 20, and the negative electrode terminal 41 is connected to the negative electrode plate 31 (the negative electrode current collector 31 m) of the electrode body 20. Has been.

  Next, the electrode body 20 will be described. The electrode body 20 is accommodated in the insulating film enclosure 16 formed in a bag shape in which only the upper UW is opened, and is accommodated in the battery case 10 in a laid state. This electrode body 20 is obtained by winding a belt-like positive electrode plate 21 and a belt-like negative electrode plate 31 on each other via a belt-like separator 34 and compressing them in a flat shape.

  The positive electrode plate 21 has a positive electrode current collector foil 22 made of a strip-shaped aluminum foil as a core material. A positive electrode active material layer 23 is provided in a strip shape on a region extending in the longitudinal direction in a part of the width direction of both main surfaces of the positive electrode current collector foil 22. The positive electrode active material layer 23 is formed of a positive electrode active material, a conductive agent, and a binder. In addition, one end in the width direction of the positive electrode current collector foil 22 is a positive electrode current collector part 21m in which the positive electrode active material layer 23 does not exist in the thickness direction of the positive electrode current collector foil 22, The positive electrode terminal 40 is connected.

  Moreover, the negative electrode plate 31 has the negative electrode current collection foil 32 which consists of strip | belt-shaped copper foil as a core material. On both main surfaces of the negative electrode current collector foil 32, a negative electrode active material layer 33 is provided in a band shape on a region extending in the longitudinal direction and part of the width direction. The negative electrode active material layer 33 is formed of a negative electrode active material, a binder, and a thickener. In addition, one end in the width direction of the negative electrode current collector foil 32 is a negative electrode current collector 31m in which the negative electrode active material layer 33 does not exist in the thickness direction of the negative electrode current collector foil 32. The negative electrode terminal 41 is connected.

  The separator 34 is a porous film made of resin, specifically, polypropylene (PP) and polyethylene (PE), and has a strip shape.

  Next, the sealing structure of the through hole 12H (injection hole) will be described. As described above, the case lid member 12 is provided with a through hole 12H (a liquid injection hole) that communicates the inside and the outside of the battery case 10. The through hole 12H is hermetically sealed with the outer sealing member 50.

As shown in FIG. 6, the outer sealing member 50 is made of metal, specifically, aluminum of the same material as the battery case 10 (case cover member 12), and the upper bottom portion 50a has a flat disk shape. The tapered side part 50b that extends continuously downward from the periphery forms a frustoconical lid. Furthermore, the lower part of the side part 50b has the collar part 50c which contacts the battery case 10 (case cover member 12) in an annular shape. And this outer side sealing member 50 welds the circumference | surroundings of the collar part 50c from the case outer side to the through-hole peripheral part 12c located in the peripheral part of the through-hole 12H among battery case 10 (case cover member 12). As a result, the through hole 12H is hermetically sealed by being fixed by the weld 51.
In addition, an inner sealing member 60 and a post-recovery release member 70 are disposed in a sealing space SS between the outer sealing member 50 and the through-hole peripheral portion 12c of the battery case 10 (case lid member 12). ing.

  Among them, as shown in FIG. 2, the inner sealing member 60 is a rubber-like elastic body, specifically, a rubber made of a resin obtained by mixing polypropylene (PP) which is a thermoplastic resin with ethylene propylene diene rubber (EPDM). And a circular metal plate 61 made of aluminum integrated with the plug member 62. And the rubber-like plug body 62 protrudes from the center part 61b inside the annular peripheral edge part 61c in the plug body forming surface 61a (the downward surface in FIG. 2) of the metal plate 61. This rubber-like plug body 62 has an annular shape whose outer diameter and inner diameter are larger than the through hole 12H, and an annular pressure contact portion 62a that becomes a portion compressed against the battery case 10 (case lid member 12); The circular pressure contact portion 62a has a truncated cone shape that protrudes downward in the figure, and includes an insertion portion 62b that is a portion that is inserted into the through hole 12H, and these are integrally connected. Here, the insertion portion 62b has a distal end portion made smaller than the diameter of the through hole 12H, and a proximal end portion made larger than the diameter of the through hole 12H. Then, the insertion portion 62b of the rubber plug 62 is fitted into the through hole 12H from the outside and press-fitted into the through hole 12H, and a part of the side surface of the insertion portion 62b is brought into close contact with the inner peripheral surface of the through hole 12H. At the same time, the annular pressure contact portion 62a is brought into pressure contact with the through hole peripheral edge portion 12c of the battery case 10 (case lid member 12) so that the through hole 12H can be sealed.

Further, as shown in FIG. 3, the post-recovery release member 70 is made of a shape memory resin, and has its shape recovered to the stored first shape K1. On the other hand, while maintaining the memory of the first shape K1, the second shape K2 is different from the first shape K1, and when the shape is recovered by raising the temperature to the glass transition temperature Tg or higher, which is the shape recovery temperature, the first shape A member that becomes the release member 70 after recovery of K1 is a release member 80 before recovery. The pre-recovery release member 80 having the second shape K2 has a cylindrical shape, and its inner diameter R2 is larger than the through hole 12H and larger than the outer diameter of the annular pressure contact portion 62a of the rubber plug 62. (See FIG. 3A). The post-recovery release member 70 having one of the first shapes K1 is also cylindrical, and its inner diameter R1 is larger than the through hole 12H, and further has a diameter larger than the outer diameter of the annular pressure contact portion 62a of the rubber plug 62. It is considered large. However, the height H1 is higher than the height H2 of the second shape K2 (see FIG. 3B).
That is, the post-recovery release member 70 is deformed along with the shape recovery from the second shape K2 to the first shape K1, and its height increases from H2 to H1.
In this embodiment, as a shape memory resin for forming the post-recovery release member 70 and the pre-recovery release member 80, polyurethane-based shape memory polymer “Diary” MM-4500 (glass transition temperature Tg = 30 ° C.) manufactured by SMP Technologies. ) Was used.

The rubber plug 62 of the inner sealing member 60 disposed in the sealing space SS is fitted from the outside into the through hole 12H before the outer sealing member 50 is fixed, as will be described later. The through hole 12H was sealed. However, after fixing the outer sealing member 50, the post-recovery release member 70 is restored to the first shape K1, so that the post-recovery release member 70 uses the metal plate 61 of the inner sealing member 60 and the same. The integrated rubber plug 62 is pushed up to release the sealing plug of the through hole 12H by the rubber plug 62 (see FIG. 6).
As described above, in the battery 1, after the outer sealing member 50 is fixed, the sealing plug of the through hole 12 </ b> H by the rubber-like plug body 62 is released by the post-recovery release member 70. For this reason, the airtightness of the through-hole 12 </ b> H is maintained only by the outer sealing member 50.

  In the present embodiment, of the through hole peripheral portion 12c of the battery case 10 (case lid member 12), the outer portion 12c2 to which the outer sealing member 50 is secured by the welded portion 51 is the inner sealing member 60 and the recovery. It is located slightly outside of the inner portion 12c1 where the rear release member 70 is disposed as viewed from the through hole 12H. The inner portion 12c1 in the vicinity of the through hole 12H has the case cover member 12 partially made thinner, and is one step lower than the outer portion 12c2 positioned outside the case lid member 12b. Has a step. As a result, the post-recovery release member 70 and the inner sealing member 60 can be easily arranged, and the height of the outer sealing member 50 is suppressed, while the outer sealing member 50 (upper bottom portion 50a, side surface portion 50b) and the inner sealing member are sealed. The distance between the metal plate 61 of the stop member 60 can be earned. However, the through hole peripheral portion 12c of the battery case 10 (case lid member 12) does not necessarily have such a stepped shape. For example, a through hole is simply drilled in a flat plate through hole peripheral portion. It may be in the form.

  Next, a method for manufacturing the battery 1 according to the first embodiment will be described. First, the separately formed belt-like positive electrode plate 21 and negative electrode plate 31 are overlapped with each other via a belt-like separator 34 and wound using a cylindrical winding core. Thereafter, the electrode body 20 is formed by compressing it into a flat shape.

  On the other hand, the case lid member 12 having the safety valve 15 and the through-hole 12H formed therein, the extended terminal member 42 and the bolt 43 are prepared, the insulating member 44 is formed by injection molding, and the positive electrode terminal 40 is formed on the case lid member 12. The negative terminal 41 is fixed.

Next, the positive electrode terminal 40 and the positive electrode current collector 21m of the electrode body 20 are connected (welded). Further, the negative electrode terminal 41 and the negative electrode current collector 31m of the electrode body 20 are connected (welded). Then, the case main body member 11 and the insulating film enclosure 16 are prepared, and the electrode body 20 is accommodated in the case main body 11 via the insulating film enclosure 16, and the opening 11H of the case main body member 11 is provided with the case lid member 12. Close with. Then, the case body member 11 and the case lid member 12 are welded by laser welding to form the battery case 10 (see FIG. 1).
Separately, an outer sealing member 50, an inner sealing member 60, and a cylindrical pre-recovery release member 80 having a second shape K2 are prepared.

  Next, the aforementioned battery is placed in a vacuum chamber, and the inside of the vacuum chamber is decompressed. In the liquid injection process, a liquid injection nozzle is inserted into the through hole 12H, and the electrolytic solution 17 is injected into the battery case 10 from the liquid injection nozzle.

Next, under reduced pressure in the vacuum chamber, the through hole 12H is temporarily sealed with the rubber plug 62 of the inner sealing member 60 (see FIG. 4). In this temporary sealing step, first, the cylindrical pre-recovery release member 80 has one end 81 (the surface of the lower DW in FIG. 4) abutting against the through-hole peripheral portion 12c of the battery case 10, and It arrange | positions in the form in which the through-hole 12H is located inside. Next, the rubber plug 62 of the inner sealing member 60 is inserted into the pre-recovery release member 80, and the insertion portion 62b of the rubber plug 62 is press-fitted into the through hole 12H. At the same time, the annular pressure contact portion 62a is pressed against the peripheral edge portion 12c of the through hole, and the through hole 12H is sealed. At the same time, the plug forming surface 61a (surface of the lower DW in FIG. 4) of the metal plate 61 of the inner sealing member 60 is formed on the other end 82 (surface of the upper UW in FIG. 4) of the release member 80 before recovery. Of these, the peripheral edge 61c is brought into contact.
Thereby, the through-hole 12H is temporarily sealed by the rubber plug 62 of the inner sealing member 60, and the arrangement of the pre-recovery release member 80 is completed.

  Thereafter, the inside of the vacuum chamber is returned to atmospheric pressure, and the battery is taken out from the vacuum chamber. However, the inside of the battery case 10 temporarily sealed with the rubber plug 62 of the inner sealing member 60 is kept at a pressure lower than the atmospheric pressure. For this reason, the following processes can be performed under atmospheric pressure while keeping the inside of the battery case 10 in a reduced pressure state.

  In the subsequent fixing step, the outer sealing member 50 covers the through hole 12H, the pre-recovery release member 80, and the inner sealing member 60 from the outside of the case, and the outer sealing member 50 (the flange portion 50c) is formed by laser welding. Then, the battery case 10 is brought into contact with the peripheral edge 12c (outer portion 12c2) of the through hole, welded over the entire periphery thereof, and airtightly fixed at the weld 51 (see FIG. 5).

In the next releasing step, the battery 1 is put into a thermostat set at 45 ° C. As a result, the pre-recovery release member 80 is heated to a temperature sufficiently exceeding the glass transition temperature Tg = 30 ° C., and the shape is restored (deformed) from the second shape K2 to the first shape K1. Then, the post-recovery release member 70 pushes up the metal plate 61 of the inner sealing member 60 and pushes up the rubber-like plug body 62 integrated therewith. Then, the insertion portion 62b of the rubber plug 62 is removed from the through hole 12H, and the hermetic plug is released. Thereby, the airtightness of the through hole 12H is maintained only by the outer sealing member 50 (see FIG. 6). Then, the battery 1 is taken out from the thermostat.
In this embodiment, since a release member made of a shape memory resin having a glass transition temperature of Tg = 30 ° C. is used, the shape does not recover at room temperature (20 to 25 ° C.), while setting of a thermostatic bath used for temperature rise. The temperature can be relatively low. Thereby, it is possible to easily raise the temperature to the glass transition temperature Tg or higher and recover the shape of the release member.

  Next, in the conditioning process (initial charge / discharge process), initial charge / discharge of the battery 1 is performed. At that time, gas such as hydrogen is generated in the battery case 10.

  Further, in the first embodiment, the airtightness between the outer sealing member 50 and the peripheral edge 12c of the through hole of the battery case 10 is inspected in the airtightness inspection process. Specifically, the battery 1 is placed in a vacuum chamber, and the inside of the vacuum chamber is decompressed. Then, a hydrogen gas detector is installed in the vicinity of the outer sealing member 50 to detect hydrogen gas.

  As described above, since the hydrogen gas generated at the time of initial charge / discharge exists in the battery case 10, there is a sealing failure between the outer sealing member 50 and the through hole peripheral portion 12 c of the battery case 10. If it occurs, hydrogen gas leaks out of the outer sealing member 50. Therefore, if hydrogen gas can be detected by the hydrogen gas detector, it can be seen that a sealing failure has occurred in the outer sealing member 50. Therefore, a battery having such a sealing failure portion can be eliminated. Thus, the battery 1 is completed.

As described above, the method for manufacturing the battery 1 according to the first embodiment includes the temporary sealing step, the fixing step, and the releasing step.
In the temporary sealing step, the rubber plug 62 of the inner sealing member 60 is fitted into the through hole 12H from the outside, and the through hole 12H is tightly plugged. At the same time, the rubber plug 62 is moved by the deformation when the pre-recovery release member 80 of the second shape K2 is restored to the first shape K1, and the sealing plug of the through hole 12H by the rubber plug 62 is released. A pre-recovery release member 80 is arranged as possible.
In the adhering step, the outer sealing member 50 covers the through hole 12H, the pre-recovery release member 80, and the inner sealing member 60 from the outside, and the outer sealing member 50 is attached to the through hole peripheral portion 12c of the battery case 10. Adherent, airtight.
In the releasing step, the temperature of the pre-recovery release member 80 is raised to restore the shape to the first shape K1, and the inner sealing member 60 rubber-like plug body 62 is moved so that the through-hole 12H is formed by the rubber-like plug body 62. Release the airtight plug.

  Prior to fixing the outer sealing member 50 to the peripheral edge 12c of the through hole, the electrolytic solution 17 injected into the battery case 10 adheres to the peripheral edge 12c of the through hole unless the through hole 12H is temporarily sealed. For example, dirt may adhere to the peripheral edge portion 12c of the through-hole, and there is a risk that the outer sealing member 50 cannot be fixed properly. However, the manufacturing method of the battery 1 includes a temporary sealing step, a fixing step, and a releasing step. Thereby, the outer sealing member 50 is appropriately attached to the through-hole peripheral portion 12c of the battery case 10 in a state where the through-hole 12H is tightly plugged (temporarily sealed) by the rubber plug 62 of the inner sealing member 60. It can be fixed. In addition, since the sealing plug of the through hole 12H by the rubber plug 62 of the inner sealing member 60 is released in the subsequent releasing step, the through hole 12H is not sealed by the rubber plug 62, but the outer sealing member. Only 50 is hermetically sealed. For this reason, in the battery 1 manufactured in this way, the airtightness of the through hole 12H by the outer sealing member 50 can be appropriately inspected at the timing before the subsequent shipment.

  Further, in the manufacturing method of the battery 1, since the airtightness between the outer sealing member 50 and the through hole peripheral edge portion 12 c of the battery case 10 is inspected after the releasing step in the manufacturing stage, the outer sealing member 50 is inspected. The battery 1 in which the airtightness between the battery case 10 and the battery case 10 is confirmed can be manufactured.

Furthermore, in this battery 1 manufacturing method, the cylindrical release members (the pre-recovery release member 80 and the post-recovery release member 70) have only to be arranged on the peripheral edge 12c of the through hole, and the arrangement of the release members is simple.
Further, the inner sealing member 60 has a metal plate 61 integrated with the rubber plug 62, and pushes up the metal plate 61 when the release member 70 after recovery is deformed. Thereby, the sealing plug of the through-hole 12H by the rubber-like plug body 62 of the inner sealing member 60 can be reliably released with a simple structure.

  Further, in the method for manufacturing the battery 1, in the temporary sealing step, the through-hole 12H is sealed with a rubber plug 62 of the inner sealing member 60 under reduced pressure. Thereby, the pressure-reduced state in the battery case 10 can be maintained thereafter. For this reason, even if gas is generated in the battery case 10 during conditioning (initial charge / discharge) or subsequent use, it is possible to suppress the internal pressure in the battery case 10 from becoming high at an early stage.

  Furthermore, in the manufacturing method of the battery 1, the temporary sealing step is performed after the electrolytic solution 17 is injected, so that the electrolytic solution 17 leaks out in the subsequent steps, and the electrolytic solution 17 is formed in the through-hole peripheral portion 12c. Therefore, it is possible to prevent a problem that the outer sealing member 50 cannot be properly fixed.

  In the battery 1, the sealing plug of the through-hole 12 </ b> H by the rubber plug 62 is released by the deformation of the post-recovery release member 70 after the outer sealing member 50 is fixed. For this reason, the fixing failure of the outer sealing member 50 due to the electrolytic solution 17 or the like adhering to the through-hole peripheral portion 12c before the outer sealing member 50 is fixed is unlikely to occur. Moreover, since the sealing plug by the rubber plug 62 is released after the outer sealing member 50 is fixed, the battery 1 can appropriately perform the airtightness test of the sealing by the outer sealing member 50. .

(Embodiment 2)
Next, a second embodiment will be described. A hybrid vehicle (vehicle) 700 (hereinafter also simply referred to as a vehicle 700) according to the second embodiment is equipped with the battery 1 according to the first embodiment, and the electric energy stored in the battery 1 is used as the drive energy of the drive source. It is used as a whole or a part (see FIG. 7).

  The automobile 700 is a hybrid automobile equipped with an assembled battery 710 in which a plurality of batteries 1 are combined and driven by using an engine 740, a front motor 720, and a rear motor 730 in combination. Specifically, the automobile 700 includes an engine 740, a front motor 720 and a rear motor 730, an assembled battery 710 (battery 1), a cable 750, and an inverter 760 on the vehicle body 790. The automobile 700 is configured to be able to drive the front motor 720 and the rear motor 730 using electrical energy stored in the assembled battery 710 (battery 1).

  As described above, since the battery 1 can be easily inspected for hermeticity of sealing by the outer sealing member 50, the reliability of the automobile 700 can be improved by mounting the battery 1 that has been inspected. Can be high.

(Embodiment 3)
Next, a third embodiment will be described. A hammer drill 800 according to the third embodiment is a battery-using device equipped with the battery 1 according to the first embodiment (see FIG. 8). In the hammer drill 800, a battery pack 810 (battery 1) including the battery 1 is accommodated in a bottom portion 821 of a main body 820, and the battery pack 810 is used as an energy source for driving the drill.

  As described above, since the battery 1 can be easily inspected for hermeticity of sealing by the outer sealing member 50, the reliability of the hammer drill 800 can be improved by mounting the battery 1 that has been inspected. Can be high.

  In the above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to the above-described first to third embodiments, and it is needless to say that the present invention can be appropriately modified and applied without departing from the gist thereof. Yes.

  For example, in Embodiment 1, although the example which utilized the through-hole 12H which connects the inside and outside of a battery case as a liquid injection hole for inject | pouring the electrolyte solution 17 was shown, it is not restricted to this. Examples of the through hole include a vent hole for releasing a gas in the battery case generated during the manufacturing process (such as initial charge / discharge). In the first embodiment, the through hole 12H is provided in the case lid member 12 of the battery case 10, but the formation position of the through hole is not limited to this. For example, the through hole may be provided on the side surface or the bottom surface of the case main body member 11.

In the first embodiment, the release members (the pre-recovery release member 80 and the post-recovery release member 70) are cylindrical, and the metal plate 61 of the inner sealing member 60 is pushed up from below and is integrated with the rubber plate. The stopper 62 was removed from the through hole 12H. However, the form of the release member is not limited to this.
For example, it is good also as a form which pushes up the metal plate 61 of the inner side sealing member 60 from the bottom with the some releasing member arrange | positioned on the through-hole peripheral part 12c, not what was integrated in the cylinder shape. Further, the metal plate 61 is not pushed up from below, but the release member is integrated with the outer sealing member 50 (upper bottom portion 50a), contracted in a height direction, and engaged with the metal of the inner sealing member 60. The plate 61 and the rubber plug 62 may be pulled up. Further, an inner sealing member that does not have a metal plate is used, and the rubber plug 62 and the release member are integrated, and the rubber plug 62 is directly pulled up by the release member integrated with the outer sealing member 50. good.
Moreover, as a shape memory material which comprises a cancellation | release member, it may replace with shape memory resin and may use the cancellation | release member of a shape memory alloy.

  Moreover, in Embodiment 2, although the hybrid vehicle 700 was illustrated as a vehicle carrying the battery 1 which concerns on this invention, it is not restricted to this. Examples of the vehicle on which the battery according to the present invention is mounted include an electric vehicle, a plug-in hybrid vehicle, a hybrid railway vehicle, a forklift, an electric wheelchair, an electrically assisted bicycle, and an electric scooter.

  Moreover, in Embodiment 3, although the hammer drill 800 was illustrated as a battery use apparatus which mounts the battery 1 which concerns on this invention, it is not restricted to this. Examples of battery-powered devices equipped with the battery according to the present invention include personal computers, mobile phones, battery-powered electric tools, uninterruptible power supply devices, various home appliances driven by batteries, office equipment, industrial equipment, etc. Is mentioned.

1 Lithium ion secondary battery (sealed battery)
10 Battery Case 11 Case Body Member 12 Case Cover Member 12H Through Hole (Liquid Injection Hole)
12c Through-hole peripheral part 15 Safety valve 17 Electrolyte solution 20 Electrode body 40 Positive electrode terminal 41 Negative electrode terminal 50 Outer sealing member 51 Welding part SS Sealing space 60 Inner sealing member 61 Metal plate 61a (metal plate) plug body formation surface 61b Central portion 61c (of the plug body forming surface of the metal plate) Peripheral portion 62 (of the plug body forming surface of the metal plate) Rubber-like plug body 70 Post-recovery release member K1 First shape R1 (Post-recovery release member (first shape) Inner diameter H1 (Recovery release member (first shape)) height 80 Pre-recovery release member K2 Second shape R2 (Pre-recovery release member (second shape)) inner diameter H2 (Recovery release member (second shape) Shape)) height Tg shape recovery temperature (glass transition temperature of shape memory resin, transformation point of shape memory alloy)
81 One end 82 (of the pre-recovery release member) The other end (of the pre-recovery release member)

Claims (6)

A battery case made of metal and having a through-hole penetrating inside and outside of itself,
An electrode body housed in the battery case;
An outer sealing member that is made of metal, covers the through hole from the outside, and is fixed to the peripheral edge of the through hole located at the peripheral edge of the through hole in the battery case, and hermetically seals the through hole;
A rubber made of a rubber-like elastic body that is disposed in a sealed space between the outer sealing member and the peripheral edge of the through hole of the battery case, and is fitted into the through hole from the outside so that the through hole can be sealed. An inner sealing member having a shaped plug,
A post-recovery release member made of a shape memory material that is arranged in the sealed space and has been restored to the first shape that has been stored,
A member that becomes a second shape different from the first shape while maintaining the memory of the first shape, and becomes the post-recovery release member of the first shape when the shape is recovered by raising the temperature to a shape recovery temperature or higher. As a release member before recovery,
When the rubber plug of the inner sealing member is fitted into the through hole from the outside to seal the through hole, and the shape of the pre-recovery release member of the second shape is restored to the first shape A temporary sealing step of disposing the pre-recovery release member so that the rubber-like plug body is moved by the deformation of the rubber-like plug body so that the hermetic plug of the through-hole by the rubber-like plug body can be released;
The outer sealing member covers the through hole, the pre-recovery release member, and the inner sealing member from the outside, and the outer sealing member is airtightly fixed to the peripheral edge of the battery case. An adhering process,
Allowed to warm to the pre-recovery release member, by shape recovery to the first shape, a release step of moving the rubber stopper, to release the sealed in the through hole by the rubber stopper, A method for manufacturing a battery comprising: A battery manufacturing method according to claim 1, comprising:
A manufacturing method of a battery provided with an airtight inspection process of inspecting airtightness between the outer side sealing member and the peripheral part of the penetration hole of the battery case after the release process. A method for producing a battery according to claim 1 or claim 2,
The pre-recovery release member having the second shape is
The inner diameter is a cylindrical shape larger than the through hole,
The post-recovery release member having the first shape is
The inner diameter is a cylindrical shape larger than the through hole, and the height is higher than the height of the second shape,
The inner sealing member has a metal plate integrated with the rubber-like plug body, and the rubber-like plug body protrudes from a central portion inside the peripheral edge portion of the plug-forming surface of the metal plate. To be in the form of
The temporary sealing step includes
The cylindrical pre-recovery release member is arranged in such a manner that one end thereof is in contact with the peripheral edge of the through hole of the battery case, and the through hole is located on the inside thereof.
Inserting the rubber-like plug body of the inner sealing member into the pre-recovery release member and the through-hole, sealing the through-hole,
A step of bringing the peripheral edge of the plug forming surface of the metal plate into contact with the other end of the release member before recovery,
The release step includes
The shape of the release member before recovery is restored to the first shape, the metal plate and the rubber plug are moved in a direction to remove the rubber plug from the through hole, and the rubber plug is used to move the metal plate and the rubber plug. A method for producing a battery, which is a step of releasing the sealing plug of the through hole. It is a manufacturing method of the battery of any one of Claims 1-3, Comprising:
The temporary sealing step includes
A method for producing a battery, which is a step of sealing the through-hole with the rubber-like plug of the inner sealing member under a reduced pressure lower than atmospheric pressure. It is a manufacturing method of the battery according to any one of claims 1 to 4,
The through hole is
A liquid injection hole for injecting an electrolyte into the battery case,
The temporary sealing step includes
A method for manufacturing a battery, which is performed after a liquid injection step of injecting the electrolytic solution through the liquid injection hole. A battery case made of metal and having a through-hole penetrating inside and outside of itself,
An electrode body housed in the battery case;
An outer sealing member that is made of metal, covers the through hole from the outside, and is fixed to the peripheral edge of the through hole located at the peripheral edge of the through hole in the battery case, and hermetically seals the through hole;
A rubber made of a rubber-like elastic body, which is disposed in a sealed space between the outer sealing member and the peripheral edge of the through hole of the battery case, and can be fitted into the through hole from the outside to seal the through hole. An inner sealing member having a shaped plug,
A post-recovery release member made of a shape memory material disposed in the sealed space and having a first shape;
A battery comprising:
The rubber plug of the inner sealing member is
The through hole is sealed by the deformation of the post-recovery release member accompanying the shape recovery to the first shape after being fitted into the through hole from the outside to seal the through hole and fixing the outer sealing member. The battery that is released.

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