JP2018045901A - Lithium ion battery and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively make use of containing space to bring advantage in ensuring a capacity, and to simplify an assembling process in connection with a lithium ion battery.SOLUTION: A lithium ion battery comprises a first-polarity current collector, a first-polarity electrode composition, a separator, a second-polarity electrode composition and a second-polarity current collector which are encased in an outer packaging body. In the lithium ion battery, a first exterior packaging part and a second exterior packaging part each have a bottom, a side wall and an opening. In the first exterior packaging part, the first-polarity current collector and the first-polarity electrode composition are encased. In the second exterior packaging part, the second-polarity current collector and the second-polarity electrode composition are encased. Further, the first exterior packaging part which contains the first-polarity current collector and the first-polarity electrode composition is arranged in the second exterior packaging part which contains the second-polarity current collector and the second-polarity electrode composition so that the first-polarity electrode composition is opposed to the second-polarity electrode composition through the separator.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lithium ion battery in which a first electrode current collector, a first electrode electrode composition, a separator, a second electrode electrode composition, and a second electrode current collector are housed in an exterior body, and a method for manufacturing the same.

  Lithium ion (secondary) batteries have been widely used in various applications in recent years as high-capacity, small and lightweight secondary batteries. A general lithium ion battery is a single battery in which a positive electrode composition layer containing a positive electrode active material and an electrolyte and a negative electrode composition layer containing a negative electrode active material and an electrolyte are laminated with a separator interposed therebetween. Is housed in a container as an exterior body.

  In such a lithium ion battery, it is preferable to maintain the performance of the lithium ion battery by sealing the single battery with a container to prevent intrusion of moisture from the outside and leakage of the electrolytic solution. As an example of such a container, what was indicated by patent documents 1 and 2 is mentioned, for example.

Japanese Patent Laid-Open No. 2006-1537 Japanese Patent Laying-Open No. 2015-165460

  However, the conventional lithium ion battery has a problem that the sealing portion is bulky because the sealing portion is formed by overlapping two exterior members. When the lithium ion battery is accommodated in a space having a small volume, the bulky sealing portion is disadvantageous in terms of securing the capacity. The battery described in Patent Document 1 enables effective utilization of the accommodation space by folding the sealing portion. Enlarging the sealed part is more effective in preventing moisture from entering from outside and leakage of the electrolyte, but increasing the area of the sealed part makes it difficult to achieve effective use of the storage space. is there.

  The present invention has been made in view of the above-described problems, and is advantageous in terms of securing capacity, since it is possible to achieve both the prevention of moisture intrusion from outside and leakage of electrolyte solution and effective utilization of the storage space. An object of the present invention is to provide a lithium ion battery that can simplify the assembly process and a method for manufacturing the lithium ion battery.

  The present invention is applied to a lithium ion battery in which a first electrode current collector, a first electrode electrode composition, a separator, a second electrode electrode composition, and a second electrode current collector are accommodated in an exterior body. And an exterior body is provided with the 1st exterior part and the 2nd exterior part, and the 1st exterior part and the 2nd exterior part have a bottom part, a side wall, and an opening, respectively, Contains the first electrode current collector and the first electrode electrode composition, the second exterior portion contains the second electrode current collector and the second electrode electrode composition, and further the first electrode current collector and The second electrode current collector and the first electrode part containing the first electrode composition are oriented so that the first electrode composition and the second electrode composition face each other with the separator interposed therebetween. By accommodating in the 2nd accommodating part which accommodated the 2nd electrode composition, at least one of the above-mentioned subject is solved.

  The first exterior part is accommodated in the second exterior part to form a laminated part in which the side wall parts of the two exterior members are overlapped, thereby forming a bulky sealing part protruding from the battery body. In addition, it is possible to further prevent moisture from entering from outside and leakage of the electrolyte.

  In addition, by having a laminated portion in which the side walls of the first exterior portion and the second exterior portion that are two exterior portions are overlapped, the strength is higher than that of a conventional battery that does not have a laminated portion of the exterior body. High, and also has the effect of having excellent resistance to breakage and deformation.

  Here, by further including a sealing portion in which the peripheral portion of the opening of the second exterior portion and a part of the first exterior portion are overlapped, sealing can be performed while keeping the accommodation space small. preferable.

  In addition, it is preferable that the first exterior portion and the second exterior portion have flexibility so that the battery can be stored in various shapes of spaces.

  The manufacturing method of the present invention also provides a lithium ion battery in which a first electrode current collector, a first electrode electrode composition, a separator, a second electrode electrode composition, and a second electrode current collector are accommodated in an outer package. Applicable to manufacturing method. And the exterior body is provided with the 1st exterior part and the 2nd exterior part which respectively have a bottom part, a side wall, and an opening part, and the 1st electrode current collector and the 1st electrode composition were stored. The second electrode current collector, the second electrode current collector, and the second electrode so that the first electrode composition and the second electrode composition face each other with the separator therebetween. A housing step for housing the composition in the second exterior portion, and a peripheral portion of the opening of the second exterior portion bent inward and overlapped with the bottom of the first exterior portion to be sealed By providing the sealing process, at least one of the above-described problems is solved.

  Here, further, a first electrode forming step in which the first electrode current collector and the first electrode composition are disposed in the first exterior part, and a second electrode current collector in the second exterior part. It is preferable to provide a 2nd electrode formation process arrange | positioned with a 2nd electrode composition.

  According to the present invention, it is advantageous in terms of securing capacity by preventing both intrusion of moisture from the outside and leakage of electrolyte solution and effective utilization of the storage space, and further simplifies the assembly process. A possible lithium ion battery and a method for manufacturing the same can be provided.

It is a perspective view which shows the lithium ion battery which is one Embodiment of this invention. It is sectional drawing of the lithium ion battery which is one Embodiment. It is process drawing which shows the manufacturing method of the lithium ion battery which is one Embodiment of this invention. It is a partially omitted perspective view showing an example of a head-mounted electronic device to which the lithium ion battery of one embodiment is applied.

(One embodiment)
With reference to FIG.1 and FIG.2, the detail is demonstrated about the lithium ion battery which is one Embodiment of this invention. FIG. 1 is a perspective view showing a lithium ion battery according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the lithium ion battery according to an embodiment, and FIG. 2B is a cross-sectional view taken along the line B-B in FIG. 1, and FIG. 2C is a cross-sectional view taken along the line C-C in FIG. 1.

  In these drawings, a lithium ion battery L of the present embodiment includes a lithium secondary single battery 1 having a substantially rectangular parallelepiped shape and a container 20 that is an exterior body that houses the lithium secondary single battery 1.

  Here, in the present invention, the lithium secondary cell 1 refers to a positive electrode in which a positive electrode composition layer including a positive electrode active material and an electrolytic solution is formed on the surface of the positive electrode current collector, a negative electrode active material, and an electrolytic solution. A negative electrode composition layer including a negative electrode formed on the surface of the negative electrode current collector, and having a structure in which the positive electrode composition and the negative electrode composition are laminated via a separator, It is a battery that does not have a terminal arrangement, electronic control unit, etc. (Reference: Japanese Industrial Standards JIS C8715-2 “Industrial Lithium Secondary Battery Cell and Battery System”). The lithium secondary cell 1 may be abbreviated as a cell.

  As shown in detail in FIG. 2, the container 20 constituting the lithium ion battery L of the present embodiment includes a first container (first exterior part) 21 and a second container (second exterior part) 22. It is divided and configured. The first container 21 and the second container 22 include bottom portions 21a and 22a, side wall portions 21b and 22b, and opening portions 21c and 22c, respectively.

  More specifically, the side wall 21b of the first container 21 is formed so as to rise substantially vertically from the bottom 21a, and has a cross section having an opening at a position facing the bottom 21a where the first pole or the second pole is disposed. Is formed in a substantially U-shaped container. On the other hand, the side wall portion 22b of the second container 22 includes a lower side wall portion 22d whose lower portion is narrowed down in the cross section and an upper side wall portion 22e that stands upright in the cross section, and serves as a counter electrode of the electrode disposed on the bottom portion 21a. An opening 22c is provided at a position facing the disposed bottom 22a. The first container is placed in the second container so that the electrode composition housed in the first container and the counter electrode composition housed in the second container face each other with the separator 4 therebetween. By housing, the opening 22c of the second container 22 is covered by the bottom 21a of the first container 21, and the peripheral portion 22f of the side wall 22b of the second container 22 and the bottom of the first container 21 are covered. An overlapping portion 23 is formed as a sealing portion by overlapping with a part of 21 a, and further, the overlapping portion 23 is sealed by a seal member (not shown), whereby the unit cell 1 is accommodated in the container 20. Is sealed.

  As shown in detail in FIG. 2, the cell 1 includes a substantially plate-like positive electrode including a positive electrode active material and an electrolyte solution on the surface of a substantially plate-like positive electrode current collector (first electrode current collector) 7. On the surface of the positive electrode 2 on which the composition layer (first electrode composition) 5 is formed, and on the surface of a substantially plate-like negative electrode current collector (second electrode current collector) 8, a negative electrode active material and an electrolyte solution And a negative electrode 3 on which a substantially flat negative electrode composition layer 6 (second electrode composition) 6 is formed and laminated with a substantially flat separator 4 interposed therebetween. It is formed in a shape.

  More specifically, the positive electrode current collector 7 is accommodated in the bottom 21a of the first container 21, and the positive electrode composition is contained in the accommodating part formed by the bottom 21a and the side wall 21b of the first container 21. A material layer 5 is accommodated. A portion 7a of the positive electrode current collector 7 rises from the bottom portion 21a of the first container 21 to the inner surface of the side wall portion 21b and further extends to the outer surface of the side wall portion 21b as shown in FIG. 2 (b). As shown in FIG. 1, the tip 7 b reaches the upper surface of the bottom 21 a of the first container 21 in the drawing. The separator 4 is provided so as to cover the opening 21 c of the first container 21.

  On the other hand, the negative electrode current collector 8 is accommodated in the bottom portion 22a of the second container 22, and the negative electrode composition layer 6 is disposed in the accommodating portion formed by the bottom portion 22a and the side wall portion 22b of the second container 22. Is housed. A part 8a of the negative electrode current collector 8 rises from the bottom 22a of the second container 22 to the inner surface of the side wall part 22b as shown in FIG. 2 (c), and further the side wall of the first container 21. The end portion 8b extends between the portion 21b and the side wall portion 22b of the second container 22 and reaches the upper surface of the bottom portion 21a of the first container 21 in the drawing as shown in FIG. And the front-end | tip parts 7b and 8b of these positive electrode collectors 7 and negative electrode collectors 8 are used as electrode terminals for taking out the power supply voltage from the lithium ion battery L of this embodiment.

  The distance between the positive electrode current collector 7 and the separator 4 and the distance between the negative electrode current collector 8 and the separator 4 are adjusted according to the capacity of the unit cell 1. The positional relationship between the electric body 8 and the separator 4 is determined so as to obtain a necessary interval.

The positive electrode active material includes positive electrode active material particles, and the positive electrode active material particles include a composite oxide of lithium and a transition metal (for example, LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , Li (Ni—Mn—Co) O). ₂ and LiMn ₂ O ₄ and parts of these transition metals substituted by other elements), transition metal oxides (eg MnO ₂ and V ₂ O ₅ ), transition metal sulfides (eg MoS ₂ and TiS) ₂ ) and conductive polymers (for example, polyaniline, polypyrrole, polythiophene, polyacetylene, poly-p-phenylene, and polycarbazole). Two or more of these may be used in combination. As the positive electrode active material particles, lithium-transition metal composite oxides are preferably used from the viewpoint of capacity and output characteristics.

The negative electrode active material includes negative electrode active material particles. As the negative electrode active material particles, graphite, non-graphitizable carbon, amorphous carbon, a polymer compound fired body (for example, a phenol resin, a furan resin, or the like is fired). Carbonized, etc.), coke (eg, pitch coke, needle coke, petroleum coke, etc.), carbon fiber, conductive polymer (eg, polyacetylene, polyquinoline, etc.), tin, silicon, and metal alloy (eg, lithium-tin alloy) , Lithium-silicon alloys, lithium-aluminum alloys and lithium-aluminum-manganese alloys) and composite oxides of lithium and transition metals (for example, Li ₄ Ti ₅ O ₁₂ ). These negative electrode active materials may be used alone or in combination of two or more.

  In the unit cell 1, the positive electrode active material particles and the negative electrode active material particles are coated active material particles in which at least a part of the surface is coated with a coating agent containing a coating resin and a conductive auxiliary agent from the viewpoint of durability and the like. It is preferable that When the periphery of the active material particles is coated with a coating agent, the volume change of the electrode is mitigated, the expansion of the electrode can be suppressed, and the deterioration due to vibration or the like generated when the arm is worn can be suppressed. . In addition, the state where the coating agent is attached to the surfaces of the positive electrode active material particles and the negative electrode active material particles is obtained by observing an enlarged observation image of the coated active material particles obtained using a scanning electron microscope (also referred to as SEM). This can be confirmed.

  Examples of the coating resin include vinyl resin, urethane resin, polyester resin, polyamide resin, epoxy resin, polyimide resin, silicone resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, and polycarbonate. Among these, vinyl resin, urethane resin, polyester resin or polyamide resin is preferable.

  As a conductive support agent, it selects from the material which has electroconductivity.

  Examples of conductive materials include metals [aluminum, stainless steel (SUS), silver, gold, copper, titanium, etc.], conductive carbon [graphite, carbon black, acetylene black, Vulcan (registered trademark), ketjen black (registered) Trademark), black pearl (registered trademark), furnace black, channel black, thermal lamp black, carbon nanotube (such as single-walled carbon nanotube and multi-walled carbon nanotube), carbon nanohorn, carbon nanoballoon, hard carbon, fullerene, etc.], and these However, the present invention is not limited to these.

  These conductive assistants may be used alone or in combination of two or more. Moreover, these alloys or metal oxides may be used. From the viewpoint of electrical stability, aluminum, stainless steel, carbon, silver, gold, copper, titanium and mixtures thereof are preferred, silver, gold, aluminum, stainless steel and carbon are more preferred, and carbon is more preferred. is there. In addition, these conductive assistants may be those in which a conductive material (a metal among the conductive auxiliary materials described above) is coated by plating or the like around a non-conductive material such as a particulate ceramic material or a resin material. Good.

  The shape of the conductive auxiliary agent is not particularly limited, and those having a spherical shape, an indeterminate shape, a fibrous shape, a single particle shape, an aggregate shape, and a combination thereof can be used. Therefore, an aggregate of fine particles having a primary particle diameter of 5 to 50 nm is preferable. The shape of the conductive auxiliary agent can be obtained by observing a magnified observation image of the conductive auxiliary agent obtained using SEM or the like and measuring particles in the visual field.

  As the conductive auxiliary agent, it is also possible to use conductive fibers. Examples of conductive fibers include carbon fibers such as PAN-based carbon fibers and pitch-based carbon fibers, conductive fibers obtained by uniformly dispersing highly conductive metal and graphite in synthetic fibers, and metals such as stainless steel. Examples thereof include fiberized metal fibers, conductive fibers in which the surface of organic fiber is coated with metal, and conductive fibers in which the surface of organic fiber is coated with a resin containing a conductive substance. Among these conductive fibers, carbon fibers are preferable.

  The coated active material particles are, for example, dropped and mixed with a resin solution containing a coating resin and a conductive auxiliary agent used as needed over a period of 1 to 90 minutes while the active material particles are put in a universal mixer and stirred at 30 to 500 rpm. Further, it is possible to obtain the mixture by mixing the conductive aid used if necessary, raising the temperature to 50 to 200 ° C. with stirring, reducing the pressure to 0.007 to 0.04 MPa, and holding for 10 to 150 minutes. It can be confirmed that the coated active material particles are obtained by observing an enlarged observation image of the coated active material particles obtained using a scanning electron microscope (also referred to as SEM).

  As the electrolytic solution, an electrolytic solution containing an electrolyte and a non-aqueous solvent used for manufacturing a lithium ion battery can be used.

As the electrolyte, those used in ordinary electrolytic solutions can be used. For example, lithium salts of inorganic acids such as LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiAsF ₆ and LiClO ₄ , LiN (CF ₃ SO ₂ ) ₂ and lithium salts of organic acids such as LiN (C ₂ F ₅ SO ₂ ) ₂ and LiC (CF ₃ SO ₂ ) _3. These electrolytes may be used alone or in combination of two kinds. You may use the above together. Among these, LiPF ₆ is preferable from the viewpoint of battery output and charge / discharge cycle characteristics.

  As the non-aqueous solvent, those used in ordinary electrolytic solutions can be used, for example, lactone compounds, cyclic or chain carbonates, chain carboxylates, cyclic or chain ethers, phosphates, nitriles. Compounds, amide compounds, sulfones, sulfolanes and the like and mixtures thereof can be used.

  A non-aqueous solvent may be used individually by 1 type, and may use 2 or more types together.

  Among the nonaqueous solvents, lactone compounds, cyclic carbonates, chain carbonates and phosphates are preferred from the viewpoint of battery output and charge / discharge cycle characteristics, and more preferred are lactone compounds, cyclic carbonates and chains. A carbonic acid ester is more preferable, and a mixed solution of a cyclic carbonate and a chain carbonate is more preferable. Particularly preferred is propylene carbonate (PC) or a mixture of ethylene carbonate (EC) and diethyl carbonate (DEC).

  In the present invention, the positive electrode active material layer and the negative electrode active material layer preferably each include the above-described coated active material particles and a fibrous conductive material from the viewpoint of reducing ionic resistance. As the fibrous conductive material, the same conductive fibers as those described above can be used, and among these, carbon fibers are preferable.

  Examples of the separator 4 include a hydrocarbon-based resin such as polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP), a porous film made of polyolefin (polyethylene, polypropylene, etc.), and a multilayer film of a porous film (for example, PP / PE / Laminated bodies having a three-layer structure of PP, etc.), microporous films made of nonwoven fabric made of polyester fiber, aramid fiber, glass fiber, etc., and those having ceramic fine particles such as silica, alumina, titania, etc. attached to their surfaces, etc. Known separators for lithium ion batteries can be used.

    As the positive electrode current collector 7 and the negative electrode current collector 8, a known metal current collector or resin current collector can be used, and among them, a resin current collector is preferable. The positive electrode current collector 7 and the negative electrode current collector 8 that are resin current collectors are composed of a non-conductive polymer material imparted with conductivity even if they are resin current collectors composed of a conductive polymer material. It may be a resin current collector.

  Among the polymer materials constituting the resin current collector, examples of the conductive polymer material include polyaniline, polypyrrole, polythiophene, polyacetylene, polyparaphenylene, polyphenylene vinylene, polyacrylonitrile, and polyoxadiazole.

  Non-conductive polymer materials include polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polycycloolefin (PCO), polyethylene terephthalate (PET), polyethernitrile (PEN), polytetrafluoroethylene (PTFE), styrene butadiene rubber (SBR), polyacrylonitrile (PAN), polymethyl acrylate (PMA), polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVdF), epoxy resin, silicone resin, or a mixture thereof. It is done.

  From the viewpoint of electrical stability, polyethylene (PE), polypropylene (PP), polymethylpentene (PMP) and polycycloolefin (PCO) are preferable, and polyethylene (PE), polypropylene (PP) and polymethylpentene are more preferable. (PMP).

  In addition, the resin current collector is intended to improve the conductivity of the resin current collector composed of a conductive polymer material, or imparts conductivity to the resin current collector composed of a non-conductive polymer material. Therefore, it is preferable that a conductive filler is included. The conductive filler is selected from fillers obtained from conductive materials. As the conductive material, it is preferable to use a material that does not have conductivity with respect to ions used as the charge transfer medium from the viewpoint of suppressing ion permeation in the current collector. Specific examples include fillers obtained from carbon materials, aluminum, gold, silver, copper, iron, platinum, chromium, tin, indium, antimony, titanium, nickel and stainless steel (SUS). From the viewpoint of corrosion resistance, the filler is preferably aluminum, stainless steel, a carbon material, nickel, and more preferably a filler obtained from a carbon material. These conductive fillers may be used alone or in combination of two or more. In addition, these conductive fillers may be those obtained by coating the metal shown above with a plating or the like around a particulate ceramic material or resin material.

  The resin current collector can be obtained by a known method described in JP 2012-150905 A and International Publication No. WO 2015/005116, and specific examples include 5 to 5 acetylene black as a conductive filler in polypropylene. Examples thereof include 20 parts dispersed and then rolled with a hot press. Moreover, the thickness is not particularly limited, and can be applied in the same manner as known ones or with appropriate changes.

  The material constituting the sealing member that seals the overlapping portion 23 is not particularly limited as long as the material has adhesiveness to the first container 21 and the second container 22 and is durable to the electrolytic solution. However, polymer materials, particularly thermosetting resins are preferred. Specific examples include epoxy resins, polyolefin resins, polyurethane resins, and polyvinylidene fluoride resins. Polyolefin resins are preferred because they are highly flexible and easy to handle.

  If the material of the exterior material constituting the container 20 including the first container 21 and the second container 22 is a material that can accommodate the positive electrode composition layer 5 and the negative electrode composition layer 6 in the container 20, Any material is suitably applicable. However, considering that there is a possibility that the electrode composition and the container 20 are in contact with each other, the material constituting the container 20 is preferably an insulating material. In addition, the container 20 is preferably sealed under reduced pressure with the electrode composition stored therein, and the material constituting the container 20 is flexible in that it can be stored in a space of any shape. It is preferable that the material has property and airtightness.

  As such a material, a laminate film is preferable. As the laminate film, a composite film in which a metal layer is interposed between an outer layer containing a heat-resistant resin film and an inner layer containing a thermoplastic resin film can be used. As the heat-resistant resin film, a polyamide resin or a polyester resin is stretched. A film or the like can be preferably used, and an unstretched polyolefin film or the like can be preferably used as the thermoplastic resin film. As a metal layer, the layer by aluminum foil, stainless steel foil, copper foil, etc. can be used. Heat resistance means that the melting point of the film is higher than the melting point of the thermoplastic resin film that forms the inner layer, which makes it possible to reliably heat seal the opening when manufacturing a lithium secondary battery. become. An example of a laminate film is a film in which both surfaces of a metal layer such as aluminum or nickel are covered with a polymer film. More specifically, a film in which the outer surface of the container 20 is formed of a heat resistant resin film and the inner surface of the container 20 is formed of a thermoplastic resin film is raised. Furthermore, among the polymer films disposed on both surfaces of the metal layer, a laminate film in which the polymer film serving as the inner surface of the container 20 is a polymer film made of a heat-fusible resin such as polyethylene and polypropylene can be used.

  Next, the manufacturing method of the lithium ion battery of this embodiment is demonstrated with reference to FIG.

  First, as shown in FIG. 3A, the positive electrode current collector 7 is accommodated on the bottom 21a of the first container 21 in which the bottom 21a and the side wall 21b are formed. The positive electrode composition layer 5 is accommodated in. There is no limitation on the method of accommodating the positive electrode composition layer 5 in the first container 21, and as an example, as shown in FIG. 3A, the nozzle 30 is inserted from the tank in which the positive electrode composition layer 5 is stored. The method of filling the positive electrode composition layer 5 in the first container 21 through the method, the method of filling the positive electrode composition layer 5 in the first container 21 with an inkjet device, and a well-known method are suitably applied. The

  Next, as shown in FIG. 3B, the flat separator 4 is placed in the opening 21c (upper surface in the figure) of the first container 21 in which the positive electrode composition layer 5 and the positive electrode current collector 7 are arranged. By arranging, the opening 21c is covered with the separator 4 as shown in FIG. The method of disposing the separator 4 is arbitrary, and as an example, as shown in FIG. 3B, the separator 4 processed (including cutting) into a predetermined size is held by a vacuum chuck 31 or the like to be first. There is a method in which the separator 4 is disposed (placed) on the opening 21c of the first container 21 by lowering the vacuum chuck 31 and placing the separator 4 above the opening 21c of the container 21.

  The separator 4 can be arranged on the negative electrode composition layer 6 arranged in the second container 22 described later, in addition to the arrangement in the opening 21c, but the opening 21c of the first container 21 can be arranged. It is preferable to arrange the separator 4 on the surface. At this time, the size of the separator 4 is processed to be slightly larger than the opening 21c of the first container 21, and a part of the vacuum chuck 31 is configured to be foldable, so that the peripheral edge of the separator 4 is It is more preferable to reach a part of the outer surface of the side wall 21b of the container 21. Thereby, even when the positive electrode composition layer 5 has a certain degree of fluidity, the opening 21c of the first container 21 is positioned below in the manufacturing process described later (FIG. 3E). Even if it is a reference), the separator 4 can seal the first container 21 to some extent to prevent the positive electrode composition layer 5 from flowing out.

  Next, as shown in FIG. 3D, the negative electrode current collector 8 is accommodated on the bottom portion 22a of the second container 22 in which the bottom portion 22a and the side wall portion 22b are formed. The negative electrode composition layer 6 is accommodated in. There is no limitation on the method of housing the negative electrode composition layer 6 in the second container 22, and various methods can be employed in the same manner as the method of housing the positive electrode composition layer 5.

  Next, as shown in FIG. 3 (e), the opening 21c and the separator 4 covering the opening 21c are positioned below, that is, from the state shown in FIG. The first container 21 containing the positive electrode current collector 7 is disposed, and in this state, the negative electrode composition layer 6 and the negative electrode current collector 8 are disposed so that the separator 4 and the negative electrode composition layer 6 are in contact with each other. The first container 21 is accommodated in the second container 22 in which is stored. Thereby, the positive electrode composition 5 and the negative electrode composition 6 are opposed to each other through the separator 4. The method of accommodating the first container 21 is also arbitrary. As an example, as shown in FIG. 3E, the bottom 21a of the first container 21 is held by the vacuum chuck 31 or the like, and the second container 22 There is a method of disposing the first container 21 in the second container 22 by disposing the vacuum chuck 31 and placing the first container 21 above the opening 22c.

  And as shown in FIG.3 (f), the lower side wall part 22d fits into this recessed part 32a in the base 32 provided with the recessed part 32a which has a shape corresponding to the outer surface of the lower side wall part 22d of the 2nd container 22. As shown in FIG. The second container 22 is temporarily fixed in such a manner that the movement of the upper side wall portion 22e of the second container 22 is restricted by the fixing plate 33, and the inner surface of the peripheral edge portion 22f of the second container 22 is restricted. After applying an unillustrated seal member, the overlapping portion 23 is sealed by crimping the peripheral edge portion 22 f to the bottom portion 21 a of the first container 21 by the crimping plate 34.

  Through the above steps, the lithium ion battery L of the present embodiment in which the unit cell 1 is sealed in the container 20 can be manufactured.

  The lithium ion battery L of the present embodiment can be suitably applied to, for example, a head-mounted electronic device using eyeglasses G having a head-mounted display as a functional unit as shown in FIG. 4 includes a front portion 40 having a pair of lenses LE, and a pair of support portions (temples: FIG. 4) that extend from both ends of the front portion 40 in substantially the same vertical direction and support the front portion 40. In Fig. 4, only one of them is shown) 41, and a head-mounted display 42 is supported by one of the temples 41 (the temple 41 on the back side in Fig. 4) and is a functional unit having an image display function.

  As shown in FIG. 4, one temple 41 is formed with a vertical groove 41a extending in the extending direction, and the lithium ion battery L of the present embodiment is accommodated in the vertical groove 41a. The pair of electrode terminals 42a of the head mounted display 42 penetrates the temple 41 and is exposed in the vertical groove 41a. These electrode terminals 42a are the electrode terminals 7b and 8b of the lithium ion battery L (both shown in FIG. 4). The power supply voltage from the lithium ion battery L is supplied to the head mounted display 42 by being in electrical contact with each other.

  Therefore, in the lithium ion battery L of the present embodiment, the overlapping portion 23 between the first container 21 and the second container 22 is one of the peripheral edge portion 22f of the second container 22 and the bottom portion 21a of the first container 21. Since the portions are overlapped with each other, the overlapping portion 23 has a simple structure and does not become bulky. This makes it possible to provide a lithium ion battery and a method for manufacturing the lithium ion battery, which is advantageous in terms of securing capacity by effectively using the accommodation space and further simplifying the assembly process.

L Lithium ion battery 1 Single cell 2 Positive electrode 3 Negative electrode 4 Separator 5 Positive electrode composition layer 6 Negative electrode composition layer 7 Positive electrode collector 8 Negative electrode collector 20 Container 21 First container 22 Second container 21a, 22a Bottom part 21b, 22b Side wall part 21c, 22c Opening part 22f Peripheral part 23 Overlapping part

Claims (5)

In a lithium ion battery in which a first electrode current collector, a first electrode electrode composition, a separator, a second electrode electrode composition, and a second electrode current collector are accommodated in an exterior body,
The exterior body includes a first exterior part and a second exterior part,
Each of the first exterior part and the second exterior part has a bottom part, a side wall, and an opening part,
The first exterior portion contains the first electrode current collector and the first electrode composition,
The second exterior part contains the second electrode current collector and the second electrode composition,
Furthermore, the first exterior part containing the first electrode current collector and the first electrode composition is formed by the first electrode composition and the second electrode composition through the separator. A lithium ion battery, which is accommodated in the second exterior part containing the second electrode current collector and the second electrode composition so as to face each other. The lithium ion battery according to claim 1,
A lithium ion battery comprising: a sealing portion in which a peripheral edge portion of the opening included in the second exterior portion and a part of the first exterior portion are overlapped. The lithium ion battery according to claim 1 or 2,
The lithium ion battery, wherein each of the first exterior part and the second exterior part has flexibility. A method of manufacturing a lithium ion battery in which a first electrode current collector, a first electrode electrode composition, a separator, a second electrode electrode composition, and a second electrode current collector are accommodated in an outer package,
The exterior body includes a first exterior part and a second exterior part each having a bottom part, a side wall, and an opening part,
The first electrode composition and the second electrode composition are opposed to each other with the first electrode current collector and the first electrode composition containing the first electrode composition interposed between the first electrode composition and the second electrode composition. An accommodating step of accommodating the second electrode current collector and the second electrode composition in the second exterior portion in which the second electrode current collector and the second electrode electrode composition are accommodated,
A sealing step of sealing a sealing portion that is bent inward and overlapped with a bottom portion of the first exterior portion and sealed. Production method. It is a manufacturing method of the lithium ion battery according to claim 4,
A first electrode forming step of disposing the first electrode current collector and the first electrode composition in the first exterior part;
A method for producing a lithium ion battery, comprising: a second electrode forming step of disposing the second electrode current collector and the second electrode composition in the second exterior part.

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