JP6611321B2 - Battery module and manufacturing method thereof - Google Patents

Description

  The present invention relates to a battery module including a stacked battery in which a plurality of lithium secondary cells are stacked in series, 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. In general lithium ion batteries, a positive electrode active material and a negative electrode active material are respectively provided on one surface of a plate-like current collector constituting a positive electrode and a negative electrode, and then heat-treated to dry the positive electrode active material and the negative electrode active material. If necessary, a lithium secondary single battery is manufactured by sandwiching a separator between the positive electrode active material and the negative electrode active material, and laminating these positive electrode active material and negative electrode active material. Layered layers were configured as battery modules.

  Lithium ion batteries using such battery modules have been proposed and realized by forming a current collector into a cylindrical shape, and then a cylindrical battery in which the shape of the entire lithium ion battery is formed into a cylindrical shape. (For example, refer to Patent Document 1).

International Publication No. 2013/038946

  However, in the above-described conventional cylindrical battery, the positive electrode, the negative electrode, and the separator are each formed into a part of a cylindrical shape (for example, a semicylindrical shape), and then individually stored in a cylindrical container. A cylindrical battery was manufactured. Therefore, there is a problem in the productivity of the battery, and there is a problem of improving the productivity.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a battery module capable of improving the productivity of a cylindrical battery module and a method for manufacturing the same.

  In the present invention, a positive electrode having a positive electrode composition layer formed on the surface of a positive electrode current collector and a negative electrode having a negative electrode composition layer formed on the surface of the negative electrode current collector are laminated via a separator. The present invention is applied to a battery module including a stacked battery in which a plurality of lithium secondary cells are stacked in series. The battery module is cylindrical, and the lithium secondary cell has a first surface including one surface of the positive electrode current collector and a second surface including one surface of the negative electrode current collector, and is formed on the first surface. A first engagement portion and a second engagement portion formed on the second surface so as to be engageable with the first engagement portion, and a pair of lithium secondary cells adjacent in the stacking direction, At least one of the above-described problems is solved by engaging the first engaging portion of one lithium secondary cell and the second engaging portion of the other lithium secondary cell. ing.

  The lithium secondary battery having the above configuration has a first surface including one surface of the positive electrode current collector and a second surface including one surface of the negative electrode current collector, and the first surface formed on the first surface. The engaging portion and the second engaging portion formed on the second surface are stacked in a state of being engaged with each other.

  Here, the lithium secondary cell has a frame-shaped seal portion that seals the outer periphery of the positive electrode and the negative electrode, and the first and second engagement portions are respectively provided on the first surface and the second surface. It is preferable to provide in the included seal part.

Furthermore, at least a part of at least one of the positive electrode composition layer and the negative electrode composition layer is coated with an active material (hereinafter referred to as a coating active material) coated with a layer comprising a conductive additive and a polymer. The electrode composition preferably includes a fibrous conductive material.

  The manufacturing method of the present invention is applied to the method for manufacturing the battery module, and a unit cell forming step of forming a lithium secondary unit cell including first and second engaging portions; Lithium in a state where the first engagement portion provided in the lithium secondary cell and the second engagement portion provided in the other lithium secondary cell adjacent in the stacking direction are engaged and positioned. At least one of the above-mentioned problems is solved by including a lamination step of forming a laminated battery by laminating a secondary unit cell while winding it on the surface of a rotatable roller.

  ADVANTAGE OF THE INVENTION According to this invention, the battery module which can aim at the productivity improvement of a cylindrical battery module and its manufacturing method can be provided.

It is a partially broken perspective view which shows the lithium ion battery with which the battery module which is one Embodiment of this invention was applied. It is a perspective view which shows a part of battery module of one Embodiment. It is sectional drawing which shows a part of battery module of one Embodiment. It is a figure which shows the outline of the manufacturing process of the battery module of one Embodiment. It is a figure which shows the outline of the manufacturing process of the battery module of one Embodiment. It is an enlarged view in A circle of FIG. It is a perspective view which shows the outline of the airship to which the battery module of one Embodiment was applied. It is a figure which shows the modification of the manufacturing process of the battery module of one Embodiment.

(One embodiment)
With reference to FIGS. 1-6, the battery module which is one Embodiment of this invention, and its manufacturing method are demonstrated.

  Here, in the present invention, the battery module means a battery module in which a plurality of lithium secondary cells are combined and accommodated in a container and terminals are attached.

  First, the battery module of this embodiment will be described with reference to FIGS. 1 to 3. 1 is a partially broken perspective view showing a lithium ion battery to which a battery module according to an embodiment of the present invention is applied, FIG. 2 is a perspective view showing a part of the battery module according to an embodiment, and FIG. It is sectional drawing which shows a part of battery module of embodiment.

  In these drawings, a lithium ion battery L to which a battery module according to an embodiment of the present invention is applied includes a laminated battery 10 in which a plurality of substantially flat lithium secondary battery cells 1 are laminated in series. As shown in FIG. 2, a battery module 20 that is arranged in a matrix on the surface of a virtual cylinder and is formed in an outer cylindrical shape as a whole forms an outer shell of the lithium ion battery L. It is configured to be stored in the outer container 21.

  Here, in the present invention, the lithium secondary cell means 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. And a negative electrode formed with a negative electrode composition layer formed on the surface of the negative electrode current collector through a separator, and does not include a battery container, terminal arrangement, electronic control device, or the like. Note that a lithium secondary cell may be abbreviated as a cell.

  As shown in detail in FIG. 3, the unit cell 1 has a substantially plate-like positive electrode composition layer 5 including a positive electrode active material and an electrolytic solution formed on the surface of a substantially rectangular plate-like positive electrode current collector 7. Similarly, the negative electrode 3 in which a substantially plate-like negative electrode composition layer 6 containing a negative electrode active material and an electrolytic solution is formed on the surface of a substantially rectangular plate-like negative electrode current collector 8 is also the same. Are laminated with a substantially plate-like separator 4 interposed therebetween, and are formed in a substantially rectangular plate shape as a whole. Thereby, the cell 1 which has the positive electrode collector 7 and the negative electrode collector 8 which oppose in an outermost layer is comprised.

  More specifically, as shown in detail in FIG. 2, the battery module 20 includes a rectangular frame-shaped seal portion 9 arranged and formed in a matrix in a plan view, and includes a positive electrode composition layer 5 and a negative electrode composition. As shown in FIG. 3, the layer 6 is formed in a frame formed by the seal portion 9. That is, as shown in detail in FIG. 3, each of the positive electrode 2 and the negative electrode 3 is sealed by the seal portion via the separator 4. Further, as shown in detail in FIG. 3, the end portion of the separator 4 is embedded in the seal portion 9. The positive electrode current collector 7 and the negative electrode current collector 8 are provided so as to cover the upper surface of the positive electrode composition layer 5 and the lower surface of the negative electrode composition layer 6 in FIG. 3, respectively. A first surface composed of the upper surface of the electric body 7 and the upper surface of the seal portion 9, and a second surface composed of the lower surface of the negative electrode current collector 6 and the lower surface of the seal portion 9 are formed.

  Further, as shown in FIG. 2, the positive electrode current collector 7 (and the negative electrode current collector 8 are omitted in FIG. 2 but are also arranged in a matrix form with a predetermined interval through a seal portion 9). Further, as shown in FIG. 3, the upper surface of the positive electrode current collector 7 and the upper surface of the seal portion 9 and the lower surface of the negative electrode current collector 8 and the lower surface of the seal portion 9 in FIG. A positive electrode current collector 7 and a negative electrode current collector 8 are disposed. As a result, in the battery module 20, as shown in FIG. 3, the pair of unit cells 1 adjacent to each other in the stacking direction of the unit cells 1 (vertical direction in FIG. 3) are in contact with the upper and lower surfaces of the seal portion 9. Are stacked.

  In the cross-sectional view shown in FIG. 3, the positive electrode current collector 7 and the negative electrode current collector 8 are positioned so as to face each other with a predetermined interval by the seal portion 9, and the separator 4, the positive electrode current collector 7, and the negative electrode current collector are positioned. The body 8 is also positioned by the seal portion 9 so as to face each other with a predetermined interval.

  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 lithium ion battery. The positional relationship between the electric body 8 and the separator 4 is determined so as to obtain a necessary interval.

  Further, as shown in FIGS. 2 and 3, in FIG. 2, the upper and lower surfaces of the seal portion 9, that is, the first surface and the second surface, are convex portions that are first engaging portions that can be engaged with each other. 11 and the recessed part 12 (refer FIG. 3) which is a 2nd engaging part are formed. More specifically, a plurality of convex portions 11 and concave portions 12 are formed on the upper surface and the lower surface of the seal portion 9 so as to surround the positive electrode current collector 7 and the negative electrode current collector 8. 3 are stacked as shown in FIG. 3, the protrusions 11 and the recesses 12 adjacent to each other in the stacking direction (vertical direction in FIG. 3) are engaged with each other, and the stacking position is positioned.

  In addition, there is no limitation on the number and the formation position of the convex part 11 and the concave part 12, and the arbitrary number and the formation position are provided on the condition that the stacking positions of the unit cells 1 that are vertically stacked as shown in FIG. 3 are positioned. Selectable.

  The positive electrode composition layer is composed of a positive electrode active material and an electrolytic solution, and the negative electrode composition is composed of a negative electrode active material and an electrolytic solution.

As the positive electrode active material particles constituting the positive electrode active material, composite oxides of lithium and transition metals (for example, LiCoO ₂ , LiNiO ₂ , LiMnO ₂ and LiMn ₂ O ₄ ), transition metal oxides (for example, MnO ₂ and V) ₂ O ₅ ), transition metal sulfides (eg, MoS ₂ and TiS ₂ ), and conductive polymers (eg, polyaniline, polypyrrole, polythiophene, polyacetylene, poly-p-phenylene, and polycarbazole).

Further, as the negative electrode active material particles constituting the negative electrode active material, graphite, non-graphitizable carbon, amorphous carbon, polymer compound fired body (for example, those obtained by firing and carbonizing phenol resin, furan resin, etc.), Coke (for example, pitch coke, needle coke and petroleum coke), carbon fiber, conductive polymer (for example, polyacetylene and polyquinoline), tin, silicon, and metal alloy (for example, lithium-tin alloy, lithium-silicon alloy, lithium) -Aluminum alloy and lithium-aluminum-manganese alloy), composite oxides of lithium and transition metal (for example, Li ₄ Ti ₅ O ₁₂ ) and the like.

In the cell 1 of the present embodiment, as the positive electrode active material and the negative electrode active material, at least a part of the surface of the positive electrode active material particles and the negative electrode active material particles is coated with a layer containing a conductive additive and a polymer. The active material is preferably included.
For example, when the periphery of the positive electrode active material particles is covered with a layer containing a conductive additive and a polymer, the volume change of the electrode is alleviated and the expansion of the electrode can be suppressed.

  Examples of the polymer 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, polycarbonate, and the like. 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.

  Specifically, metal [aluminum, stainless steel (SUS), silver, gold, copper, titanium, etc.], carbon [graphite and carbon black (acetylene black, ketjen black, furnace black, channel black, thermal lamp black, single layer Carbon nanotubes and multi-walled carbon nanotubes, etc.)], and mixtures thereof, but are not limited thereto.

  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. These conductive assistants may be those obtained by coating a particulate ceramic material or resin material with a conductive material (metal among the conductive auxiliary materials described above) by plating or the like.

  It is also possible to use conductive fibers as the conductive auxiliary. 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 is prepared by, for example, dropping and mixing the resin solution containing the polymer over 1 to 90 minutes while mixing the active material particles in a universal mixer and stirring at 30 to 500 rpm, and further mixing a conductive additive. Then, the temperature can be increased to 50 to 200 ° C. with stirring, and the pressure can be reduced to 0.007 to 0.04 MPa, and then maintained for 10 to 150 minutes.

  As the electrolytic solution contained in the positive electrode composition layer and the negative electrode composition layer, an electrolytic solution containing an electrolyte used for producing a lithium ion battery and a nonaqueous solvent 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 . 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 liquid 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).

  The positive electrode composition layer and the negative electrode composition layer preferably contain a fibrous conductive material in addition to the coating active material and the electrolytic solution. When the fibrous conductive material is included, the conductivity between the coated active materials can be favorably maintained even when the positive electrode composition layer and the negative electrode composition layer are deformed in an arc shape. As a fibrous conductive material, the same thing as the said conductive fiber can be used, and a preferable thing is also the same.

  As the separator 4, polyethylene, polypropylene, etc., microporous membrane film made of polyolefin, multilayer film of porous polyethylene film and polypropylene, non-woven fabric made of polyester fiber, aramid fiber, glass fiber, etc., and silica on the surface thereof, Examples include those having ceramic fine particles such as alumina and titania attached thereto.

  As the positive electrode and negative electrode current collectors 7 and 8, a metal current collector or a resin current collector can be used. As the metal current collector, a known metal current collector can be used. For example, the metal current collector is selected from the group consisting of copper, aluminum, titanium, nickel, tantalum, niobium, hafnium, zirconium, zinc, tungsten, bismuth, antimony, and alloys containing one or more of these, and stainless steel alloys. It is preferable that it consists of 1 or more types. The metal current collector may be formed from a thin plate or a metal foil, or a metal layer may be formed on the surface of the substrate by a technique such as sputtering, electrodeposition, or coating.

  The polymer material constituting the resin current collector may be a conductive polymer or a polymer having no conductivity.

  Polymer materials include polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polycycloolefin (PCO), polyethylene terephthalate (PET), polyether nitrile (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.

  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 containing the conductive polymer material, or to impart conductivity to the resin current collector containing the polymer material having no conductivity. Therefore, it is preferable that a conductive filler is included. The conductive filler is selected from materials having conductivity. Preferably, from the viewpoint of suppressing ion permeation in the current collector, it is preferable to use a material that does not have conductivity with respect to ions used as the charge transfer medium. Specific examples include, but are not limited to, carbon materials, aluminum, gold, silver, copper, iron, platinum, chromium, tin, indium, antimony, titanium, nickel, and the like. These conductive fillers may be used alone or in combination of two or more. Moreover, these alloy materials, such as stainless steel (SUS), may be used. From the viewpoint of corrosion resistance, aluminum, stainless steel, carbon material, nickel, and more preferably carbon material are preferred. 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.

  Specific examples of the resin current collector include those obtained by dispersing 5 to 20 parts of acetylene black as a conductive filler in polypropylene and then rolling 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 seal portion 9 is not particularly limited as long as it is a material that has adhesiveness to the positive electrode and the negative electrode current collectors 7 and 8 and is durable to the electrolytic solution. A thermosetting resin is preferred. Specific examples include epoxy resins, polyolefin resins, polyurethane resins, and polyvinylidene fluoride resins. Epoxy resins are preferable because they are highly durable and easy to handle.

  As long as the material which comprises the battery exterior container 21 is a material which can accommodate the battery module 20 in the battery exterior container 21, arbitrary materials are applicable suitably. However, considering that the heat generated from the battery module 20 is quickly diffused and dissipated, a material having high thermal conductivity such as metal is preferable. However, since a short circuit may occur when the battery module 20 and the battery outer casing 21 are in direct contact with each other, it is preferable to form an insulator layer or the like on the inner surface of the battery outer casing 21.

  Next, a method for manufacturing the battery module 20 having the above configuration will be described with reference to FIGS.

  First, as shown in FIG. 4, a strip-like (long sheet-like) separator sheet 30 wound in a roll shape is placed on a support member (not shown) in a predetermined transport direction (from left to right in FIG. 4). In the horizontal direction), and continuously supplied, and as shown in FIG. 4 and FIG. 5A, a rectangular shape as shown in FIG. The frame lower layer portion 31a in which the recess 12 is formed at a predetermined position (see FIG. 2) on the upper surface thereof is repeatedly formed.

  The frame lower layer portion 31a (and the frame upper layer portion 31b described later) constitutes the seal portion 9, and the method of forming the frame lower layer portion 31a and the frame upper layer portion 31b is appropriately selected from known ones. In the example shown in FIG. 4, the material for forming the seal portion 9 is melted and dropped onto the separator sheet 30 by the nozzle 32 to form the frame lower layer portion 31a (and the frame upper layer portion 31b). doing. In addition, the frame lower layer portion 31a (and the frame upper layer portion 31b) may be formed at a predetermined position on the separator sheet 30 by an inkjet device. Moreover, the method of forming the concave portion 12 on the upper surface of the frame lower layer portion 31a may be appropriately selected from well-known methods, and as an example, the frame lower layer portion 31a is formed by controlling the dropping amount of the nozzle 32. In addition, a method of forming the recess 12 on the upper surface is an example. Or after forming the frame lower layer part 31a, you may form the recessed part 12 by embossing.

  Next, as shown in FIG. 4 and FIG. 5B, the negative electrode active material that constitutes the negative electrode composition layer 6 in a rectangular space defined by the frame lower layer portion 31 a and the separator sheet 30, The mixture of the electrolyte and the electrolyte solution is dropped by the nozzle 33 and filled to at least the height of the frame lower layer portion 31a, so that a rectangular space defined by the frame lower layer portion 31a and the separator sheet 30 is formed. The negative electrode composition layer 6 is filled and formed. Further, after this filling, the negative electrode active material may be uniformly dispersed by applying vibration and impact to the separator sheet 30 by a vibration applying means (not shown). In the illustrated example, the negative electrode composition layer 6 is formed first, but it goes without saying that the positive electrode composition layer 5 may be formed first.

  Next, as shown in FIG. 4 and FIG. 5C, the negative electrode composition filled and formed in advance in a predetermined size, more specifically, in a space defined by the frame lower layer portion 31 a and the separator sheet 30. A negative electrode current collector 8 cut to a size that covers the upper surface of the physical layer 6 in the drawing is disposed on the upper surface of the negative electrode composition layer 6 in the drawing. The method of disposing the negative electrode current collector 8 on the negative electrode composition layer 6 may be appropriately selected from well-known methods. In the illustrated example, after the negative electrode current collector 8 is held by the vacuum chuck 34, this vacuum is applied. The chuck 34 is disposed above the negative electrode composition layer 6. Further, the vacuum chuck 34 is lowered until the negative electrode current collector 8 reaches the upper surface of the negative electrode composition layer 6, and then held by the vacuum chuck 34. The technique of canceling is taken.

  Next, as shown in FIG. 4 and FIG. 5D, the separator sheet 30 in which the frame lower layer portion 31 a, the negative electrode composition layer 6, and the negative electrode current collector 8 are formed and arranged is transported to the separator sheet 30. After turning upside down by a roller 35 that rotates at a speed corresponding to the speed, as shown in FIG. 4 and FIG. 5 (e), the frame lower layer portion 31a is formed on the separator sheet 30 at a predetermined interval. A substantially identical space to the rectangular space to be formed is defined, and as shown in FIG. 2, a frame upper layer portion 31b in which convex portions 11 are formed at predetermined locations on the upper surface thereof is repeatedly formed. Since the formation method of the frame upper layer portion 31b and the convex portion 11 is the same as the formation method of the frame lower layer portion 31a and the concave portion 12, the description thereof is omitted here.

  Next, as shown in FIG. 4 and FIG. 5 (f), a positive electrode active material that constitutes the positive electrode composition layer 5 in a rectangular space defined by the frame upper layer portion 31 b and the separator sheet 30. A mixture of the electrolytic solution is dropped by the nozzle 36 and filled to the height of at least the frame upper layer portion 31b, so that a rectangular space defined by the frame upper layer portion 31b and the separator sheet 30 is formed. The negative electrode composition layer 6 is filled and formed.

  Next, as shown in FIGS. 4 and 5 (g), the size of the positive electrode composition layer 5 filled and formed in the space defined by the frame upper layer portion 31b and the separator sheet 30 covers the upper surface in the drawing. The positive electrode current collector 7 cut in advance is placed on the upper surface of the positive electrode composition layer 5 in the drawing using a vacuum chuck 37 or the like. Thereby, the cell 1 of this embodiment as shown in FIG.5 (h) is formed.

  As shown in FIGS. 4 and 6, the surface of the substantially cylindrical or columnar roller 38 is formed with the convex portions 11 and the concave portions 12 formed on the upper and lower surfaces of the unit cell 1 being engaged with each other. A battery module 20 as shown in FIG. 1 is formed by winding a continuous body of the unit cells 1. At this time, as shown in FIG. 4, the continuous body of the unit cells 1 is applied to the surface of the roller 38 by using a pressing roller 40 or the like in which an urging force is applied to the surface of the roller 38 by the urging means 39 or the like. By pressing toward each other, the stacked unit cells 1 are wound while being in close contact with each other.

  Thereafter, the battery module 20 is housed in the battery outer container 21, and the lithium ion battery L of the present embodiment is manufactured.

  Therefore, according to the battery module 20 of the present embodiment, the protrusions 11 and the recesses 12 of the pair of unit cells 1 adjacent to each other in the vertical direction (that is, in the stacking direction) are engaged with each other. Positioning can be performed easily. Thereby, the battery module 20 capable of facilitating relative positioning and fixing of the stacked unit cells 1 can be realized.

  In particular, the battery module 20 of the present embodiment is formed in an outer cylindrical shape. For example, when the battery module 20 of the present embodiment is used as a structure and power source of an airship P as shown in FIG. Even if a stress associated with the difference between the atmospheric pressure and the pressure inside the airship P is generated in the battery module 20 due to the change in the flight altitude, the relative positioning and fixing of the single cells 1 are performed. It is possible to respond sufficiently.

  Moreover, according to the manufacturing method of the battery module 20 of this embodiment, since the battery module 20 is manufactured by winding the cell 1 around the surface of the roller 38, the battery module 20 is manufactured continuously. Therefore, the productivity of the cylindrical battery module 20 can be greatly improved.

(Modification)
The details of the battery module and the manufacturing method thereof according to the present invention are not limited to the above-described embodiment, and various modifications are possible. As an example, in the above-described embodiment, as shown in FIG. 2, the convex portion 11 and the concave portion 12 are formed on the upper and lower surfaces of the unit cell 1, respectively, but are located in the outermost layer and the innermost layer of the battery module 20. Since it is not necessary to provide the convex part 11 and the recessed part 12 about the cell 1, respectively, you may employ | adopt the structure which abbreviate | omits these convex part 11 and the recessed part 12. FIG.

  Moreover, there is no limitation in the shape, number, etc. of the convex part 11 and the recessed part 12 which are formed in the cell 1, and it should just select suitably considering the intensity | strength etc. which are calculated | required by the battery module 20. FIG. As an example, in the above-described embodiment, as shown in FIG. 2, the convex portion 11 is formed on the surface of the unit cell 1 corresponding to the outer layer direction of the battery module 20, but the unit cell 1 corresponding to the outer layer direction of the battery module 20. You may form the recessed part 12 in the surface of this.

  In the above-described embodiment, as shown in FIGS. 4 and 6 and FIG. 8A, the continuous body of the unit cells 1 is wound around the surface of the roller 38 having a substantially circular cross section. The cross-sectional shape of 38 is not limited, and various cross-sectional shapes can be adopted as long as the continuous body of the unit cells 1 can be wound around the surface. As an example, a roller 38 having an elliptical cross section as shown in FIG. 8B, and a roller 38 having a circular sectional deformation (curved shape with a constant curvature) as shown in FIG. 8C. Also good.

  Furthermore, in the above-described embodiment, as shown in detail in FIG. 6, the length of the seal portion 9 is not changed in order to engage the convex portions 11 and the concave portions 12 of the unit cells 1 adjacent in the stacking direction. In addition, the lengths of the positive electrode composition layer 5 and the negative electrode composition layer 6 (the length in the circumferential direction of the battery module 20) were increased toward the outer layer of the battery module 20, but the positive electrode composition Instead of making the lengths of the layer 5 and the negative electrode composition layer 6 constant, the length of the seal portion 9 may be increased toward the outer layer of the battery module 20.

L Lithium ion battery 1 Single cell 2 Positive electrode 3 Negative electrode 4 Separator 5 Positive electrode composition 6 Negative electrode composition 7 Positive electrode current collector 8 Negative electrode current collector 9 Sealing part 10 Stacked battery 11 Convex part 12 Concave part 20 Battery module 21 Battery exterior container

Claims (5)

A lithium secondary unit in which a positive electrode having a positive electrode composition layer formed on the surface of a positive electrode current collector and a negative electrode having a negative electrode composition layer formed on the surface of a negative electrode current collector are laminated via a separator. In a battery module including a stacked battery formed by stacking a plurality of batteries in series,
The battery module is cylindrical,
The lithium secondary cell has a first surface including one surface of the positive electrode current collector and a second surface including one surface of the negative electrode current collector,
A first engagement portion formed on the first surface and a second engagement portion formed on the second surface so as to be engageable with the first engagement portion;
Pair of rechargeable lithium battery cells that adjoin in the stacking direction, the second engaging portion having said first engaging portion and the other of said rechargeable lithium battery cells included in one of the rechargeable lithium battery cells Are engaged with each other. The battery module according to claim 1,
The lithium secondary cell has a frame-shaped seal portion that seals the outer periphery of the positive electrode and the negative electrode,
It said first and second engagement portions, the battery modules are provided on the seal portion contained respectively in the first surface and the second surface. The battery module according to claim 1 or 2,
A battery module comprising an active material in which at least one of the positive electrode composition layer and the negative electrode composition layer is coated with a layer comprising a conductive additive and a polymer. The battery module according to claim 3, wherein
The electrode composition is a battery module including a fibrous conductive material. A method for producing the battery module according to claim 1,
A unit cell forming step of forming a lithium secondary unit cell comprising the first and second engaging portions;
Is positioned to engage with said second engaging portion provided in the lithium secondary battery cells of the other which adjoin in the stacking direction as the first engagement portion provided on the rechargeable lithium battery cells method for producing a battery module, which comprises a lamination step of forming a laminated battery by stacking while wound on the surface of the rotatable roller said rechargeable lithium battery cells in a state.

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