JP5730096B2 - Thin film electrochemical device - Google Patents

Description

  The present invention has an electrode laminate in which a positive electrode and a negative electrode are laminated via a separator, and the electrode laminate is housed and sealed in a container made of a metal laminate film together with an electrolyte. The present invention relates to an electrochemical element.

  In recent years, with the diversification of information, various ultra-thin electronic devices such as electronic paper, IC tags, multi-function cards, and electronic keys have been put to practical use. It is. As characteristics required for this laminate type battery, in addition to light and long life, strength characteristics against bending are also required.

  Patent Document 1 discloses a thin battery in which a flat wound electrode body is housed in a metal laminate film container. In Patent Document 1, an aluminum laminate film formed by laminating an insulating resin layer, an aluminum foil, and a molten resin layer is used as a metal laminate film. Then, the two laminated films are overlapped and thermally sealed along the outer peripheral edge thereof to be hermetically sealed to form a rectangular bag-shaped container.

  The thin battery of Patent Document 1 has a problem that there is a limit to forming a thin battery because the flat wound electrode body is accommodated in the container. On the other hand, a laminated battery in which sheet-like electrodes (positive electrode and negative electrode) are laminated has been put into practical use. In this stacked type battery, it is possible to reduce the thickness of the battery as compared with the wound type battery as in Patent Document 1. FIG. 9 shows a conventional example of a laminated type lithium primary battery 70. In this lithium primary battery 70, a container 71 made of a metal laminate film is used, and lead terminals 72 and 73 connected to the positive electrode and the negative electrode are drawn out from the hermetically sealed portion 74 of the container 71 to the outside of the container.

JP 2003-151512 A

  By the way, in the thin film type lithium primary battery 70 as shown in FIG. 9, since the lead terminals 72 and 73 are formed thin, the strength of the lead terminals 72 and 73 cannot be sufficiently ensured. For this reason, as shown in FIG. 10, the lead terminals 72 and 73 of the lithium primary battery 10 are easily bent. Moreover, the cross section of the metal laminate film (metal layer) is exposed at the end of the container 71. Therefore, the lead terminals 72 and 73 are bent and the lead terminals 72 and 73 come into contact with the metal layer of the metal laminate film, and the lead terminals 72 and 73 are short-circuited through the metal layer.

  As a countermeasure against this, as shown in FIG. 11, a lithium primary battery 76 in which a support tab 75 for reinforcing the lead terminals 72 and 73 is newly provided is examined. Specifically, the support tab 75 is formed by extending one of the front and back metal laminate films into a tab shape. In the primary battery 76, the lead terminals 72 and 73 are bonded and fixed to the surface of the support tab 75 using a low melting point resin adhesive layer formed on the surface of the laminate film. In this way, the strength of the lead terminals 72 and 73 can be increased.

  However, when heat is applied by soldering or the like when connecting external wiring or external terminals to the lead terminals 72 and 73 of the primary battery 76, the adhesive layer of the support tab 75 is melted. In this case, the adhesive strength between the lead terminals 72 and 73 is weakened. Further, if the melted adhesive layer flows out from the interface between the lead terminals 72 and 73 and the laminate film, there is a problem that the insulation is lowered and the lead terminals 72 and 73 and the laminate film are short-circuited.

  The present invention has been made in view of the above-mentioned problems, and the object thereof is to provide a thin film electrochemical device capable of ensuring the sealing performance of a container made of a metal laminate film and reliably reinforcing lead terminals. It is to provide.

Means [1] to [ 3 ] for solving the above problems are listed below.

[1] It has an electrode laminate in which a positive electrode and a negative electrode are laminated via a separator, and the electrode laminate is housed in a container made of a metal laminate film together with an electrolytic solution, and the metal laminate film is used as an outer periphery. A thin-film electrochemical element in which a hermetically sealed portion is formed by heat welding along, and has a structure for pulling out lead terminals respectively connected to the positive electrode and the negative electrode from the hermetically sealed portion to the outside of the container And a laminated structure in which a reinforcing resin plate for reinforcing the lead terminal is interposed between the metal laminate films, and the reinforcing resin plate is formed from a low melting point resin layer that heat-welds the metal laminate films together. also the melting point is configured to include a high refractory resin layer, wherein the lead terminals via the low melting point resin layer is fixed to the surface of the reinforcement resin plate, the accessory Tab of use resin plate, said extending outside the end portion of the lead terminal so as to completely cover the back of the lead terminals, the low melting point resin layer on the surface of the tab portion of the reinforcing resin sheet A thin film type in which the back side of the lead terminal is fixed by being thermally welded via the surface, and the surface side of the lead terminal is exposed, while the back side of the lead terminal is embedded in the low melting point resin layer Electrochemical element.

Therefore, according to the invention described in the means 1, when connecting the lead terminal of the electrochemical element to an external device or the like, heat is applied in a temperature range from the temperature higher than the melting point of the low melting point resin layer to the melting point of the high melting point resin layer. Additional processing can be performed. When this processing is performed, even if the low melting point resin layer is melted, the high melting point resin layer is not melted and is interposed between the lead terminal and the metal laminate film, thereby preventing a short circuit between the lead terminal and the metal laminate film. be able to. Moreover, since the high melting point resin layer is also interposed in the hermetically sealed portion of the metal laminate film, the adhesion between the lead terminal and the low melting point resin layer can be sufficiently enhanced. In this case, there is no gap between the lead terminal and the low melting point resin layer in the hermetically sealed portion, and it is possible to reliably prevent moisture from entering the container. Further, the strength of the lead terminal can be sufficiently ensured by the reinforcing resin plate. As a result, deterioration of the characteristics of the electrochemical element can be avoided, and long-term storage characteristics can be improved .
In addition, since the tab portion of the reinforcing resin plate extends outward from the end portion of the lead terminal so as to completely cover the back surface of the lead terminal, the lead terminal can be reliably reinforced by the reinforcing resin plate. It is possible to avoid a short circuit due to bending of the lead terminal.

  [2] In the means 1, the metal laminate film is composed of an outer resin layer as an outermost layer of the container, a metal layer made of aluminum foil, and the low melting point resin layer. A thin film type electrochemical element comprising the low melting point resin layer of the layer and the high melting point resin layer interposed between the low melting point resin layers.

  According to the invention described in the means 2, when the heat-pressing is performed in a state where the reinforcing resin plate is interposed between the metal laminate films in the hermetically sealed portion, the low melting point resin layer on the surface of the reinforcing resin plate becomes the metal laminate. Melts with the low melting point resin layer of the film. The reinforcing resin plate and the metal laminate film are thermally welded through the low melting point resin layer. At this time, since the high-melting point resin layer of the reinforcing resin plate does not melt, the high-melting point resin layer can reliably improve the adhesion to the metal laminate film and the lead terminal. Moreover, the lead terminal can be fixed to the reinforcing resin plate by thermally welding the lead terminal through the low melting point resin layer of the reinforcing resin plate. As a result, it is possible to sufficiently secure the strength of the lead terminal.

  [3] In means 1 or 2, the high melting point resin layer constituting the reinforcing resin plate is made of polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyether ketone, polyether ether ketone, polyether sulfone and polyimide. The thin film electrochemical device according to claim, wherein the thin film electrochemical device is formed using at least one selected.

  By using the high melting point resin layer as in the means 3, it is possible to reliably prevent a short circuit between the lead terminal and the metal laminate film. In particular, it is more preferable to use a resin material having low hygroscopicity such as polyethylene naphthalate as the high melting point resin layer. If this low hygroscopic resin is used, the mixing of moisture into the container can be surely prevented, and the long-term storage characteristics of the electrochemical device can be improved. Further, the melting point of the high melting point resin layer is preferably higher by 100 ° C. than the melting point of the low melting point resin layer. If it does in this way, heat resistance of a high melting point resin layer can fully be secured.

As described in detail above, according to the invention according to any one of means 1 to 3 , the thin film type electrochemical device capable of ensuring the sealing property of the container made of the metal laminate film and reliably reinforcing the lead terminal. It is to provide an element.

The top view which shows the lithium primary battery of one Embodiment. Sectional drawing in the AA of the lithium primary battery in FIG. Sectional drawing in the BB line of the lithium primary battery in FIG. Sectional drawing in the CC line of the lithium primary battery in FIG. Explanatory drawing which shows the secondary process in a support tab. The graph which shows the high temperature, high humidity test result of a lithium primary battery. Explanatory drawing which shows the measuring method of tab intensity | strength. The graph which shows the measurement result of tab strength. The top view which shows the conventional lithium primary battery. The top view which shows the conventional lithium primary battery. The top view which shows the conventional lithium primary battery.

  Hereinafter, an embodiment in which the present invention is embodied in a lithium primary battery as a thin film electrochemical device will be described in detail with reference to the drawings. FIG. 1 is a plan view showing a lithium primary battery 10 according to the present embodiment, and FIG. 2 is a cross-sectional view taken along line AA of the lithium primary battery 10 in FIG. 3 is a cross-sectional view taken along line BB of the lithium primary battery 10 in FIG. 1, and FIG. 4 is a cross-sectional view taken along line CC of the lithium primary battery 10 in FIG. Note that the lithium primary battery 10 of the present embodiment is a thin laminate type battery having a thickness of 0.45 mm or less.

  As shown in FIG. 1 and FIG. 2, the lithium primary battery 10 includes a positive electrode 21 supported by a positive electrode current collector 23 and a negative electrode 31 supported by a negative electrode current collector 33 stacked via a separator 41. An electrode laminate 11 is provided. In the lithium primary battery 10, the electrode laminate 11 is hermetically sealed in the container 51 together with the nonaqueous electrolytic solution. As the nonaqueous electrolytic solution, an electrolytic solution in which lithium trifluoromethanesulfonate, lithium bistrifluoromethanesulfonimide or the like is dissolved as a solute in butyl carbonate, ethylene carbonate, propylene carbonate or the like is used.

  The separator 41 is made of a non-conductive porous body having durability against an electrolytic solution, an electrode active material, and the like and having continuous air holes. In the present embodiment, a nonwoven fabric made of polypropylene is used as the separator 41. The thickness of the separator 41 is preferably thin in order to reduce the internal resistance of the capacitor, but can be appropriately set in consideration of the amount of electrolyte retained, the flowability, the strength, and the like.

The positive electrode 21 includes a positive electrode active material made of manganese dioxide (MnO ₂ ), a carbon-based conductive agent such as acetylene black or graphite, and a binder made of polyvinylidene fluoride (PVdF). The positive electrode current collector 23 is a metal foil for collecting current while supporting the positive electrode 21 and is made of a stainless steel foil having a thickness of 20 μm. Nickel plating (not shown) is applied to one surface (upper surface in FIG. 2) of the positive electrode current collector 23, and the positive electrode 21 is formed on the nickel plating. The positive electrode current collector 23 is formed in a rectangular shape in plan view, and a positive electrode lead terminal 25 is welded to one of the four sides. The lead terminal for positive electrode 25 is drawn out of the container through the hermetic sealing portion 52 of the container 51.

  The negative electrode 31 is made of a lithium foil as a negative electrode active material, and is bonded to one surface of the negative electrode current collector 33. As the negative electrode 31, a lithium alloy foil (for example, an aluminum-lithium alloy foil) may be used instead of the lithium foil. The negative electrode current collector 33 is a metal foil for collecting current while supporting the negative electrode 31, and is made of, for example, a nickel foil having a thickness of 20 μm. The negative electrode current collector 33 is formed in a rectangular shape in plan view, and a negative electrode lead terminal 35 is welded to one of the four sides. Similarly to the positive electrode lead terminal 25, the negative electrode lead terminal 35 is also drawn out of the container through the hermetically sealing portion 52 of the container 51.

  A container 51 of the lithium primary battery 10 is a container made of a metal laminate film obtained by processing two aluminum laminate films (metal laminate films) 53 obtained by laminating an aluminum foil on a resin film into a rectangular bag shape.

  In the container 51, a hermetically sealed portion 52 is formed by thermally welding a laminate film 53 in a strip shape along the outer peripheral edge, and the container 51 is hermetically sealed by the hermetically sealed portion 52. Sealing by thermal welding is performed in a state where the positive electrode lead terminal 25 and the negative electrode lead terminal 35 are sandwiched between the front and back laminate films 53.

  The container 51 is provided with a support tab 58 for reinforcing the lead terminals 25 and 35. In the present embodiment, the support tab 58 extends the backside laminate film 53 of the front and back laminate films 53 in a tab shape, and covers the tab-shaped portion with a tab film 59 (reinforcing resin plate). It is formed by that. The support tab 58 extends outward from the ends of the lead terminals 25 and 35 so as to completely cover the back surfaces of the lead terminals 25 and 35.

  As shown in FIGS. 3 and 4, the aluminum laminate film 53 of the present embodiment includes an insulating resin layer 55 (outer resin layer) made of nylon resin, a metal layer 56 made of aluminum foil, and an acid-modified polypropylene resin. It is a laminate film having a three-layer structure in which a molten resin layer 57 (low melting point resin layer) made of (PPa) is sequentially laminated. In addition, you may form the container 51 using the metal laminate film material which consists of metal foil other than aluminum foil.

  In the present embodiment, in the container 51, the sealing and sealing portions 52 on three sides other than the side from which the lead terminals 25 and 35 are drawn are formed by thermally welding the molten resin layers 57 of the front and back laminate films 53. ing. Further, as shown in FIG. 3, the sealing and sealing portion 52 on the lead terminals 25, 35 side has two tab films 59 interposed between the front and back laminate films 53, and between the tab films 59. It is formed by sandwiching the lead terminals 25 and 35 and thermally welding the molten resin layer 57 and the tab film 59 of the laminate film 53.

  The tab film 59 is a film having a three-layer structure in which a heat-resistant resin layer 61 (high melting point resin layer) is interposed between two molten resin layers 57 (low melting point resin layer). The molten resin layer 57 in the tab film 59 is formed using an acid-modified polypropylene resin (PPa) that is the same resin material as the molten resin layer 57 of the laminate film 53. The heat-resistant resin layer 61 is formed using polyethylene naphthalate resin (PEN) which is a resin material having a melting point higher than that of the molten resin layer 57. In the present embodiment, the melting point of the molten resin layer 57 is 145 ° C., and the melting point of the heat-resistant resin layer 61 is 268 ° C.

  In the sealing and sealing part 52 on the side of the lead terminals 25 and 35 in the container 51, the molten resin layer 57 of the laminate film 53 and the molten resin layer 57 of the tab film 59 are thermally welded, and the lead terminals 25 and 35 are sandwiched. The molten resin layers 57 of the two tab films 59 are thermally welded. Thereby, the container 51 is hermetically sealed.

  Further, the width of one tab film 59 sandwiching the lead terminals 25 and 35 is substantially equal to the sealing length of the hermetic sealing portion 52, and the width of the other tab film 59 is equal to the sealing width of the hermetic sealing portion 52. It is longer than the stop length. This long tab film 59 is extended from the hermetic sealing portion 52 to the outside of the container to cover the surface of the support tab 58 (see FIGS. 1 and 4). In the support tab 58, the surfaces of the lead terminals 25 and 35 are thermally welded and fixed by the molten resin layer 57 of the tab film 59. As described above, the support tab 58 is a part that supports the lead terminals 25 and 35, and the insulating resin layer 55, the metal layer 56, the molten resin layer 57, and the like from the surface side (lower side in FIG. 4) of the laminate film 53. The heat resistant resin layer 61 and the molten resin layer 57 are laminated.

  Next, a method for manufacturing the lithium primary battery 10 will be described.

  The positive electrode 21 is produced by the following procedure. First, a sheet-like stainless steel foil is prepared, and partial nickel plating is performed on one surface. Furthermore, a rectangular positive electrode current collector 23 having a thickness of 20 μm is produced by cutting the stainless steel foil into a predetermined size.

Further, a positive electrode active material made of manganese dioxide (MnO ₂ ), a carbon-based conductive agent such as acetylene black or graphite, and a binder made of polyvinylidene fluoride (PVdF) are mixed so as to have a predetermined mass ratio. To do. A positive electrode active material slurry is prepared by adding and dissolving N-methyl-2-pyrrolidone (NMP) or the like as an organic solvent to the mixture. And after apply | coating a positive electrode active material slurry so that it may become a thickness of about 100 micrometers on the nickel plating of the positive electrode electrical power collector 23, it dries at the temperature of 100 degreeC in the vacuum, and produces the positive electrode 21.

  The negative electrode 31 is produced according to the following procedure. First, a sheet-like nickel foil is prepared, and the nickel foil is cut into a predetermined size to produce a rectangular negative electrode current collector 33 having a thickness of 20 μm. Moreover, the negative electrode 31 is formed on one surface of the negative electrode current collector 33 by superimposing the lithium foil cut into a predetermined size on the negative electrode current collector 33 and pressing the lithium foil with a predetermined pressure.

Thereafter, the positive electrode lead terminal 25 is ultrasonically welded to the positive electrode current collector 23, and the negative electrode lead terminal 35 is ultrasonically welded to the negative electrode current collector 33. Further, the electrode laminate 11 is formed by laminating the positive electrode 21 supported by the positive electrode current collector 23 and the negative electrode 31 supported by the negative electrode current collector 33 via the separator 41. Moreover, lithium bis (trifluoromethane sulfone) imide represented by LiN (SO ₂ CF ₃ ) ₂ as a solute is dissolved in propylene carbonate to prepare a non-aqueous electrolyte.

  Next, a heat welding process of the laminate film 53 is performed. In this heat welding step, first, two laminated films 53 are prepared, and the two laminated films 53 are overlapped with the molten resin layers 57 facing each other and facing inward. Then, the laminate film 53 is hermetically sealed by heat welding by applying heat at 170 ° C. to the outer peripheral edge of the laminate film 53 with a heating and pressurizing jig (not shown). Here, first, at the outer peripheral edge of the laminate film 53, the other three sides other than the side on the lead-out side of each lead terminal 25, 35 are hermetically sealed to form a bag-like container 51 having one side opened. To do.

  Then, the electrode laminate 11 is accommodated in the container 51 from the opening side of the container 51. Further, the non-aqueous electrolyte is injected into the container 51 using the opening of the container 51 as an inlet. Thereafter, in the container 51, two tab films 59 are arranged inside the laminate film 53 of the opening portion, and the opening portion is sandwiched between the positive lead terminal 25 and the negative lead terminal 35 with the tab film 59. Sealed and sealed by heat welding. Also here, heat is applied to the opening portion of the laminate film 53 by applying heat at 170 ° C. by a heating and pressing jig (not shown). As a result, the tab film 59 sandwiching the lead terminals 25 and 35 is thermally welded via the molten resin layer 57, and the laminate film 53 and the tab film 59 are thermally welded via the molten resin layer 57. By processing (primary processing) the laminate film 53 in this way, the container 51 is hermetically sealed.

  Thereafter, secondary processing for heat welding the portion of the support tab 58 is performed. At the time of the secondary processing, as shown in FIG. 5, the heating and pressing jig 64 is pressed from the side of the tab film 59 on which the positive electrode lead terminal 25 and the negative electrode lead terminal 35 are arranged on the support tab 58. Pressurize. As a result, the tab film 59 and the laminate film 53 of the support tab 58 are thermally welded by the molten resin layer 57, and the lead terminals 25 and 35 are thermally welded and fixed to the surface of the support tab 58 by the molten resin layer 57. The The lithium primary battery 10 is manufactured through the above steps.

  The present inventors conducted a storage test on the lithium primary battery 10 (Example) manufactured as described above under high temperature and high humidity conditions (specifically, a temperature of 60 ° C. and a humidity of 90%). The change of the internal resistance of the lithium primary battery 10 with respect to the storage period (days) was confirmed. In addition, as a comparative example, a lithium primary battery (conventional example) in which the tab film 59 in the support tab 58 was omitted was manufactured, and the change in internal resistance in the high temperature and high humidity test was also confirmed for the lithium primary battery of the conventional example. FIG. 6 shows the test results of the lithium primary batteries 10 of these examples and conventional examples.

  As shown in FIG. 6, in the lithium primary battery of the conventional example, moisture was mixed in the container 51 in a period of about 30 days, and the internal resistance rapidly increased. Thus, when the internal resistance of the battery increases, the battery capacity cannot be taken out and the battery does not function. Further, the container 51 also swells. On the other hand, in the lithium primary battery 10 of the embodiment, moisture can be prevented from being mixed into the container 51, and an increase in internal resistance is suppressed to a low level. For this reason, in the lithium primary battery 10 of an Example, battery capacity can be taken out over a long period of time.

  In addition, the inventors measured the tab strength of the lithium primary battery 10 manufactured as described above. Here, as shown in FIG. 7, the lithium primary battery 10 is fixed with the positive electrode lead terminal 25 and the negative electrode lead terminal 35 facing upward, and the positive electrode lead terminal 25 and the negative electrode lead terminal 35 (support The crushing strength of the support tab 58 was measured by pressing the push-pull gauge 65 from above the tab 58). The result is shown in FIG. As shown in FIG. 8, the crushing strength of the tab where the bending of the support tab 58 (lead terminals 25 and 35) occurs was 15N to 16N (1.5 kgf to 1.6 kgf). Incidentally, the crushing strength of the tab is also measured in the conventional lithium primary battery 70 (see FIG. 9) in which the support tab 58 is omitted and in the conventional lithium primary battery 76 (see FIG. 11) in which the tab film 59 in the support tab 58 is omitted. did. The crushing strength of the tabs in these conventional lithium primary batteries 70 and 76 was 3N to 4N (0.3 kgf to 0.4 kgf). Thus, in the lithium primary battery 10 of the present embodiment, the strength of the lead terminals 25 and 35 could be increased from about 4 times to about 5 times that of the conventional case.

  Therefore, according to the present embodiment, the following effects can be obtained.

  (1) In the lithium primary battery 10 according to the present embodiment, the support tab 58 for reinforcing the lead terminals 25 and 35 includes a heat-resistant resin layer 61 having a melting point higher than that of the molten resin layer 57. A film 59 is provided. In this way, when connecting the lead terminals 25 and 35 of the lithium primary battery 10 to an external device or the like, the temperature is from 145 ° C. or higher which is the melting point of the molten resin layer 57 to less than 268 ° C. which is the melting point of the heat-resistant resin layer 61. Processing with heat can be performed in the range. When this processing is performed, even if the molten resin layer 57 is melted, the heat resistant resin layer 61 is not melted and is interposed between the lead terminals 25 and 35 and the laminate film 53. For this reason, a short circuit between the lead terminals 25 and 35 and the laminate film 53 can be prevented.

  (2) In the lithium primary battery 10 of the present embodiment, the tab film 59 and the laminate are laminated in a state where the tab film 59 is interposed between the front and back laminate films 53 in the sealing and sealing portion 52 on the lead terminals 25 and 35 side. The film 53 is heat-welded. When this heat welding is performed, the heat-resistant resin layer 61 of the tab film 59 is not melted, so that the adhesion between the molten resin layer 57 and the lead terminals 25 and 35 can be sufficiently enhanced by the heat-resistant resin layer 61. Therefore, in the sealing / sealing portion 52, the lead terminals 25, 35 and the molten resin layer 57 can be brought into close contact with each other without any gap, and moisture can be reliably prevented from entering the container 51. In addition, the lead terminals 25 and 35 can be thermally welded by the molten resin layer 57 of the tab film 59, and the lead terminals 25 and 35 can be securely fixed to the support tab 58. Thereby, the strength of the lead terminals 25 and 35 can be sufficiently secured. As a result, characteristic deterioration of the lithium primary battery 10 can be avoided, and long-term storage characteristics can be improved.

  (3) In the lithium primary battery 10 of the present embodiment, polyethylene naphthalate resin (PEN) is used as the heat resistant resin layer 61 constituting the tab film 59. This polyethylene naphthalate resin is a resin having low hygroscopicity. For this reason, by interposing the tab film 59 in the hermetic sealing portion 52, it is possible to reliably prevent moisture from being mixed into the container 51, and to improve the long-term storage characteristics of the lithium primary battery 10.

  (4) In the lithium primary battery 10 of the present embodiment, the support tab 58 extends outward from the ends of the lead terminals 25 and 35 so as to completely cover the back surfaces of the lead terminals 25 and 35. If it does in this way, the lead terminals 25 and 35 can be reliably reinforced by the support tab 58, and the short circuit by bending of the lead terminals 25 and 35 can be avoided.

  In addition, you may change embodiment of this invention as follows.

  In the above embodiment, polyethylene phthalate (PEN) is used as the heat resistant resin layer 61 (high melting point resin layer) of the tab film 59 that functions as a reinforcing resin plate, but is not limited thereto. Specifically, as a material for forming the heat-resistant resin layer 61, polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyether ketone (PEK), polyether ether ketone (PEEK), polyether sulfone (PES) and A resin material such as polyimide (PI) may be used.

  In the above embodiment, the tab film 59 is provided on the front surface side and the back surface side of the lead terminals 25 and 35 so as to sandwich the positive electrode lead terminal 25 and the negative electrode lead terminal 35 in the hermetic sealing portion 52. In this case, the space between the positive electrode lead terminal 25 and the negative electrode lead terminal 35 is filled with the molten resin layer 57, but the heat resistant resin layer 61 may be provided also in that portion. Specifically, the tab film 59 is bent in a crank shape and disposed so as to be interposed between the positive lead terminal 25 and the negative lead terminal 35. If it does in this way, the insulation between each lead terminal 25 and 35 can be improved. In this case, three tab films 59 are interposed in the sealing / sealing portion 52. Further, four or more tab films 59 may be interposed in the sealing / sealing portion 52, but in that case, the sealing / sealing portion 52 becomes thick. For this reason, when insulation is ensured, it is preferable to form the sealing / sealing portion 52 thin with two tab films 59 interposed, as in the above embodiment.

  In the lithium primary battery 10 of the above embodiment, the electrode stack 11 in which the pair of the positive electrode 21 and the negative electrode 31 is stacked is accommodated in the container 51, but the electrode in which a plurality of pairs of the positive electrode 21 and the negative electrode 31 are stacked You may store a laminated body in the container 51. FIG.

  In the lithium primary battery 10 of the above embodiment, the positive electrode lead terminal 25 and the negative electrode lead terminal 35 are drawn out from the same direction, but the present invention is not limited to this, and the positive electrode lead terminal 25 and the negative electrode lead terminal It is good also as a structure by which the terminal 35 is pulled out in the mutually opposite direction.

  In the above embodiment, the embodiment is embodied in the lithium primary battery 10, but the electrochemical element stored in the container 51 made of a metal laminate film may be used for a battery or a capacitor other than the lithium primary battery. The invention may be embodied.

  Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the embodiments described above are listed below.

  (1) The thin film electrochemical element according to any one of means 1 to 4, wherein the thin film electrochemical element is a thin film lithium primary battery.

  (2) The thin-film electrochemical element according to means 2, wherein the high melting point resin layer constituting the reinforcing resin plate is formed using polyethylene naphthalate.

  (3) The thin film electrochemical element according to (2), wherein the melting point of the high melting point resin layer constituting the reinforcing resin plate is 100 ° C. higher than the melting point of the low melting point resin layer.

  (4) In the means 2, the portion supporting the lead terminal has a structure in which the outer resin layer, the metal layer, the low melting point resin layer, the high melting point resin layer, and the low melting point resin layer are laminated in order from the surface side. A thin-film electrochemical element characterized by

DESCRIPTION OF SYMBOLS 10 ... Lithium primary battery as a thin film type electrochemical element 11 ... Electrode laminated body 21 ... Positive electrode 25 ... Lead terminal for positive electrode as a lead terminal 31 ... Negative electrode 35 ... Lead terminal for negative electrode as a lead terminal 41 ... Separator 51 ... Container 52 ... Sealing and sealing part 53 ... Aluminum laminate film as metal laminate film 55 ... Insulating resin layer as outer resin layer 56 ... Metal layer 57 ... Molten resin layer as low melting point resin layer 59 ... Tab as reinforcing resin plate Film 61 ... heat resistant resin layer as high melting point resin layer

Claims (3)

An electrode laminate comprising a positive electrode and a negative electrode laminated via a separator, the electrode laminate being housed in a metal laminate film container together with an electrolyte, and heating the metal laminate film along an outer peripheral edge A thin-film electrochemical element in which a hermetically sealed portion is formed by welding,
A laminated structure in which a lead terminal connected to each of the positive electrode and the negative electrode is pulled out from the hermetically sealed portion to the outside of the container, and a reinforcing resin plate for reinforcing the lead terminal is interposed between the metal laminate films Have
The reinforcing resin plate is configured to include a high melting point resin layer having a melting point higher than that of the low melting point resin layer for thermally welding the metal laminate films,
The lead terminal is fixed to the surface of the reinforcing resin plate via the low melting point resin layer ,
The tab portion of the reinforcing resin plate is extended outside the end portion of the lead terminal so as to completely cover the back surface of the lead terminal,
The back surface of the lead terminal is fixed by heat welding to the surface of the tab portion of the reinforcing resin plate via the low melting point resin layer, and the back surface of the lead terminal is exposed while the surface side of the lead terminal is exposed. A thin-film electrochemical element characterized in that the side is buried in the low-melting point resin layer . The metal laminate film is composed of an outer resin layer which is the outermost layer of the container, a metal layer made of aluminum foil, and the low melting point resin layer,
2. The thin film type electric device according to claim 1, wherein the reinforcing resin plate includes two layers of the low melting point resin layer and the high melting point resin layer interposed between the low melting point resin layers. Chemical element.   The high melting point resin layer constituting the reinforcing resin plate is made of at least one selected from polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyether ketone, polyether ether ketone, polyether sulfone and polyimide. The thin film electrochemical device according to claim 1 or 2, wherein the thin film electrochemical device is formed.

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