JP6315269B2 - Sealed battery module and manufacturing method thereof - Google Patents

Description

  The present invention relates to a sealed battery module and a method for manufacturing the same.

  2. Description of the Related Art In recent years, attention has been drawn to electric vehicles that use an electric motor as a drive source, and so-called hybrid electric vehicles that combine an electric motor as a drive source and other drive sources. In such a vehicle, a battery capable of realizing a high capacity and a high voltage for supplying electricity as energy to the electric motor is mounted. As the battery, for example, a secondary battery represented by a nickel-cadmium battery, a nickel-hydrogen battery, a lithium ion battery, or the like that can be repeatedly charged and discharged is used as a battery cell.

  The battery is constituted by a battery pack in which a battery module in which battery cells are stacked and arranged and a plurality of the battery modules are further assembled.

  In general, when a battery cell is formed into a battery module, first, one battery cell in which an electrode body is sealed with an electrolyte and an exterior body such as a laminate film is manufactured. Next, a plurality of the battery cells are arranged, housed in a metal case or the like and assembled into a battery module. That is, the conventional battery module is manufactured by the assembly | attachment for every battery cell (for example, patent document 1).

JP 2014-78498 A

  Here, when the battery cell is modularized, if the battery module can be manufactured simultaneously with the manufacturing of the plurality of battery cells, the manufacturing of the battery module can be simplified. Therefore, the time, manufacturing cost, and number of parts required for battery modularization can be greatly reduced, and consequently the manufacturing time and cost of the battery pack can be suppressed.

  The present invention has been made in view of such circumstances, and the object of the present invention is to simplify battery module formation, and to provide a sealed battery module capable of suppressing manufacturing time and cost in battery module formation and its It is to provide a manufacturing method.

Accordingly, the present inventors have intensively studied to realize that a battery module is manufactured by assembling a plurality of battery cells at the same time instead of assembling each battery cell in modularization of battery cells.
The sealed battery module according to the present invention includes a plurality of flat-shaped electrode bodies that include a positive electrode element and a negative electrode element and are electrically connected in series or in parallel at the joint, and the thickness direction of the electrode bodies is the front and back surfaces of the battery module. A partition plate formed of a plate-like body, in which a part of the plurality of electrode bodies are arranged in a line on the one surface side and the remaining parts in a row on the other surface side in a direction orthogonal to the thickness direction, An exterior formed by deforming the plate-like body into a shape following the external shape of the electrode body, which is fixed so as to be sandwiched from the front and back sides, and in which the storage space for housing each electrode body together with the electrolyte is partitioned together with the partition plate And the partition plate is formed by using a multilayer in which the resin layer (33), the metal layer (34), and the resin layer (33) are laminated in this order, or the multilayer plate It is a laminated member formed by laminating a plurality of layers. Excluding those overlapped Te, and excluding those bonding the multilayer with an adhesive).

By adopting the above configuration, in the sealed battery module according to the present invention, a plurality of electrode bodies are enclosed in one case. Therefore, the present invention simplifies battery modularization compared to conventional battery modules in which each electrode body is enclosed in a case and manufactured as a battery cell, and then assembled into a case by assembling the battery cell and encapsulating it in a case. can do. That is, since the battery cell and the case of the battery module in the battery module can be unified , the manufacturing time and the number of parts in the battery module can be reduced, and the manufacturing cost can be reduced.

Further, in the sealed battery module according to the present invention, each electrode body is housed and sealed together with the electrolyte in a partitioned housing space created by the case. That is, since the electrolytic solution exists independently in each storage space, the voltage of one electrode body can be secured in each storage space. Therefore, for example, when the electrode bodies are connected in series, the sealed battery module according to the present invention can ensure a voltage corresponding to the number of electrode bodies.

In the sealed battery module according to the present invention, a plurality of electrode bodies are arranged in a row on both the front and back surfaces of the partition plate. Therefore, a more compact battery module can be realized. That is, when a plurality of sealed battery modules according to the present invention are arranged to form a battery pack, the space occupied by the battery pack can be reduced while ensuring a desired voltage.

A method for manufacturing a sealed battery module according to the present invention includes an electrode body group forming step in which a plurality of electrode bodies are arranged in a row and electrically connected in series at a plurality of joints to form an electrode body group; In the electrode body group disposing step, the electrode body group disposing step of disposing one of the joint portions and sandwiching the front and back surfaces of the partition plate formed from the plate-shaped body, and the electrode body group disposing step A sandwiching step having a form following the outer shape of the disposed electrode body group and sandwiching the electrode body group from the front and back directions of the partition plate with an exterior body that partitions the storage space for storing each electrode body together with the electrolytic solution, And a sealing step for liquid-tightening adjacent storage spaces after the sandwiching step, and the partition plate includes a multilayer in which a resin layer (33), a metal layer (34), and a resin layer (33) are stacked in this order. Laminated section formed by using alone or by laminating a plurality of the multilayers It is (excluding those overlapped by bending the multilayer, and excluding those bonding the multilayer with an adhesive).

  By adopting the above configuration, the method for manufacturing a sealed battery module according to the present invention includes a step of enclosing a plurality of electrode bodies in one case. Therefore, compared with the conventional method for manufacturing a battery module, which includes a step of encapsulating each electrode body in a case to produce a battery cell, and a step of assembling the battery cell and further enclosing it in a case to form a battery module. The manufacturing method of the sealed battery module according to the invention can simplify the process. That is, since the case of the battery cell and the battery module in the battery module can be unified, the manufacturing time and the number of parts in the manufacturing process of the present invention can be reduced, and the manufacturing cost can be reduced.

  Further, in the sealed battery module manufactured by the manufacturing method according to the present invention, each electrode body is electrically connected in series, and is stored and sealed in a partitioned storage space formed by the case together with the electrolytic solution. Therefore, it is possible to ensure the voltage of one electrode body, and therefore it is possible to ensure a voltage corresponding to the number of electrode bodies.

  Further, in the sealed battery module manufactured by the manufacturing method according to the present invention, a plurality of electrode bodies are arranged in a row on both the front and back surfaces of the partition plate. Therefore, a more compact battery module can be realized. That is, when a plurality of sealed battery modules manufactured by the manufacturing method according to the present invention are arranged to form a battery pack, the space occupied by the battery pack can be reduced while securing a desired voltage.

It is a perspective view which shows the sealed battery module which concerns on a reference form . It is the figure which showed typically a part of sectional drawing of the sealed battery module which concerns on a reference form . It is a perspective view of a sealed battery module according to the embodiment. It is the figure which showed typically a part of sectional drawing of the sealed battery module which concerns on embodiment . It is the figure which showed typically sectional drawing of the electrode body in the sealed battery module which concerns on this invention. It is sectional drawing which shows typically the electrode body group formation process in the manufacturing process of the sealed battery module which concerns on embodiment . It is sectional drawing which shows typically the electrode body group arrangement | positioning process in the manufacturing process of the sealed battery module which concerns on embodiment . It is sectional drawing which shows typically the clamping process in the manufacturing process of the sealed battery module which concerns on embodiment . It is sectional drawing which shows typically the sealing process in the manufacturing process of the sealed battery module which concerns on embodiment . It is sectional drawing which shows typically the laminated structure of the case in the sealed battery module which concerns on this invention. It is sectional drawing which shows typically the laminated structure of the partition board in the sealed battery module which concerns on embodiment . It is sectional drawing which shows typically the other laminated structure of the partition board in the sealed battery module which concerns on embodiment .

  Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. It should be noted that matters other than matters specifically mentioned in the present specification and necessary for carrying out the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field.

  In the present specification and the like, the battery cell in the sealed battery module includes a lithium secondary battery, a lithium ion capacitor, an electric double layer capacitor, and the like. Hereinafter, the battery cell in the sealed battery module of the present invention will be described by taking a lithium secondary battery as an example.

  First, the general configuration of the lithium secondary battery will be outlined. In the present specification, the “lithium secondary battery” refers to a secondary battery that uses lithium ions as electrolyte ions and is charged / discharged by movement of charges accompanying the lithium ions between the positive and negative electrodes. Secondary batteries generally referred to as lithium ion batteries (or lithium ion secondary batteries), lithium polymer batteries, lithium-air batteries, lithium-sulfur batteries, and the like can be included in the lithium secondary batteries in this specification. Further, in this specification, the “active material” refers to a substance (compound) involved in power storage on the positive electrode side or the negative electrode side. That is, it refers to a substance that is involved in the insertion and extraction of electrons during battery charge / discharge. In addition, the lithium secondary battery in this invention is not limited to what was shown to the following embodiment, In the range which does not change the summary, it can change suitably and can implement.

  The sealed battery module according to the present invention includes an electrode body that includes a positive electrode element and a negative electrode element, and a case that is deformed into a shape that follows the external shape of the electrode body.

  As shown in FIG. 5, the electrode body 21 includes a positive electrode element 22, a negative electrode element 23, a separator 24, a positive electrode assembly 25, and a negative electrode assembly 26. The shape of the electrode body 21 is not particularly limited. For example, the electrode body 21 has a plurality of rectangular shapes between a positive electrode element 22 formed in a plurality of rectangular plates and a negative electrode element 23 formed in a plurality of rectangular plates. The separators 24 that are formed are alternately stacked to form a flat shape. Alternatively, the positive electrode element 22 and the negative electrode element 23 may be formed in a flat shape by winding and pressing a layer in which the positive electrode element 22 and the negative electrode element 23 are alternately stacked via a separator 24.

  In the positive electrode element 22, a layer (positive electrode mixture layer) made of a positive electrode current collector 22a and a positive electrode mixture containing a positive electrode active material, a conductive additive, and a binder is formed on one surface or both surfaces of the positive electrode current collector 22a. Has the structure.

A positive electrode active material consists of an active material which can occlude / release lithium ion. Such a positive electrode active material includes, for example, lithium having a layered structure represented by Li _{1 + x} MO ₂ (−0.1 <x <0.1, M: Co, Ni, Mn, Al, Mg, etc.) Transition metal oxide, LiMn ₂ O ₄ or LiMn ₂ O ₄ spinel lithium manganese oxide in which a part of the element is replaced with another element, and LiMPO ₄ (M: Co, Ni, Mn, Fe, etc.) It is desirable to consist of any of the olivine type compounds represented.

Lithium-containing transition metal oxide of the above layered structure, for _{example, LiCoO 2, LiNi 1-x} Co xy Al y O 2 (0.1 ≦ x ≦ 0.3,0.01 ≦ y ≦ 0.2), And an oxide containing at least Co, Ni and Mn (LiMn _1/3 Ni _1/3 Co _1/3 O ₂ , LiMn _5/12 Ni _5/12 Co _1/6 O ₂ , LiNi _3/5 Mn _1/5 Co _1/5 O ₂ or LiNi _0.5 Co _0.2 Mn _0.3 ) is preferable.

  The positive electrode current collector 22a is preferably made of, for example, an aluminum foil or an aluminum alloy foil. The thickness of the positive electrode current collector 22a varies depending on the size and capacity of the battery, but is preferably 1 to 20 μm, for example.

  The positive electrode element 22 includes a positive electrode mixture containing the above-described positive electrode active material, a conductive additive such as graphite, acetylene black, carbon black, and fibrous carbon, and a binder such as polyvinylidene fluoride (PVDF). A paste-like or slurry-like composition uniformly dispersed using a solvent such as methyl-2-pyrrolidone (NMP) is prepared (the binder may be dissolved in the solvent). This composition is intermittently applied onto the belt-like positive electrode current collector 22a and dried. You may adjust the thickness of a positive mix layer by press processing as needed. The positive electrode element 22 is obtained by cutting the long positive electrode substrate thus obtained into a predetermined shape.

  The thickness of the positive electrode mixture layer in the positive electrode element 22 is preferably 30 to 100 μm per side. Moreover, as for content of each structural component in a positive mix layer, it is desirable that they are positive electrode active material: 90-98 mass parts, conductive support agents: 1-5 mass parts, binder: 1-5 mass parts.

  The positive electrode assembly 25 is a bonding portion for electrically connecting to another electrode body. The positive electrode assembly 25 is formed by laminating the respective positive electrode current collectors 22 b that are not provided with the positive electrode mixture layer extending from the positive electrode element 22. The positive electrode assembly 25 is electrically connected to each other by bonding to the positive electrode or negative electrode assembly of another electrode body. Alternatively, the electrode bodies may be electrically connected by providing electrode terminals on the positive electrode assembly 25 and bonding the electrode terminals together.

  The negative electrode element 23 has a structure in which a negative electrode current collector 23a and a layer (negative electrode mixture layer) containing a negative electrode active material capable of occluding and releasing lithium ions are formed on one surface or both surfaces of the negative electrode current collector 23a.

Negative electrode active materials include graphite, pyrolytic carbons, cokes, glassy carbons, fired organic polymer compounds, mesocarbon microbeads (MCMB), and carbon that can occlude and release lithium ions such as carbon fibers. It is desirable to consist of one or a mixture of two or more system materials. Alternatively, the negative electrode active material may be an element such as Si, Sn, Ge, Bi, Sb, or In, an alloy of Si, Sn, Ge, Bi, Sb, or In, a lithium-containing nitride, or a lithium metal such as lithium oxide. It is preferably made of any one of a compound (LiTi ₃ O ₁₂ or the like) that can be charged and discharged at a near low voltage, lithium metal, and a lithium / aluminum alloy.

  The negative electrode current collector 23a is preferably a copper foil. Copper foils are roughly classified into electrolytic copper foils and rolled copper foils depending on the manufacturing method. Electrolytic copper foil is relatively inexpensive. The thickness of the negative electrode current collector 23a varies depending on the size or capacity of the battery, but is preferably 1 to 20 μm, for example.

  The negative electrode element 23 is composed of the negative electrode active material described above, a binder (PVDF, a mixed binder of rubber binder such as styrene butadiene rubber (SBR) and carboxymethyl cellulose (CMC)), and graphite, acetylene black as necessary. A paste-like or slurry-like composition is prepared by uniformly dispersing a negative electrode mixture containing a conductive aid such as carbon black using a solvent such as NMP or water (the binder is dissolved in the solvent). May be). This composition is intermittently applied onto the strip-shaped negative electrode current collector 23a and dried. You may adjust the thickness or density of a negative mix layer by press processing as needed. The long negative electrode substrate thus obtained is cut into a predetermined shape, and the negative electrode element 23 is obtained.

  The thickness of the negative electrode mixture layer in the negative electrode element 23 is preferably 30 to 100 μm per side. Moreover, it is preferable that content of each structural component in a negative mix layer is 90-98 mass parts of negative electrode active materials, and 1-5 mass parts of binders. Moreover, when using a conductive support agent, it is preferable that content of the conductive support agent in a negative mix layer is 1-5 mass parts.

  The negative electrode assembly 26 is a joint portion for electrical connection with other electrode bodies. The negative electrode assembly 26 is formed by laminating the respective negative electrode current collectors 23 b that are not provided with the negative electrode mixture layer extending from the negative electrode element 23. The negative electrode assembly 26 is electrically connected to each other by bonding to the positive electrode or the negative electrode assembly of another electrode assembly. Moreover, electrode bodies may be electrically connected by providing electrode terminals on the negative electrode assembly 26 and joining the electrode terminals together.

  The separator 24 includes a porous film that is interposed between the positive electrode element 22 and the negative electrode element 23 and transmits lithium ions. The porous film is preferably made of a thermoplastic resin having a melting point of about 80 to 140 ° C., and specifically, preferably made of a polyolefin polymer such as polypropylene or polyethylene. Although the thickness of a porous film does not have a restriction | limiting in particular, It is desirable that it is 10-50 micrometers.

As the electrolytic solution, for example, a solution (nonaqueous electrolytic solution) in which a solute such as LiPF ₆ or LiBF ₄ is dissolved in a high dielectric constant solvent or an organic solvent can be used. As the high dielectric constant solvent, any of ethylene carbonate (EC), propylene carbonate (PC), and γ-butyrolactone (BL) can be used. As the organic solvent, a low viscosity solvent such as linear dimethyl carbonate (DMC), diethyl carbonate (DEC), or methyl ethyl carbonate (EMC) can be used.

As the solvent of the electrolytic solution, it is preferable to use a mixed solvent of the above-described high dielectric constant solvent and low viscosity solvent. Alternatively, PVDF, a rubber-based material, an alicyclic epoxy, a material having an oxetane-based three-dimensional crosslinked structure, and the like may be mixed and solidified into the above-described solution to form a polymer electrolyte layer. Alternatively, an inorganic solid electrolyte layer made of an inorganic material may be employed instead of the separator and the electrolytic solution. Examples of the inorganic solid electrolyte include at least one inorganic structure having a crystal structure selected from the group of perovskite type, NASICON type, LISICON type, thio-LISICON type, γ-Li ₃ PO ₄ type, garnet type, and LIPON type. Those containing a solid electrolyte material are desirable.

  As shown in FIG. 7, it is desirable that the cases 2 and 12 for covering the electrode bodies 4 and 14 together with the electrolytic solution are formed by deforming the plate-like body 28. The plate-like body 28 is composed of a multilayer laminated member in which an outer layer 29, a metal layer 30, and an inner layer 31 are laminated in this order. Further, it is desirable that an adhesive layer be interposed between the outer layer 29 and the metal layer 30 and between the inner layer 31 and the metal layer 30.

  The outer layer 29 constituting the plate-like body 28 of the cases 2 and 12 is required to be a resin layer having rigidity to withstand external impacts and having excellent flexibility in order to ensure moldability. Therefore, a stretched film of a heat resistant resin film such as a polyamide resin or a polyester resin is preferably used. For example, biaxially stretched nylon (ONy) or biaxially stretched polyethylene terephthalate (OPET). The outer layer 29 is desirably configured to include at least one or two or more of these heat resistant resin films. When the outer layer 29 is composed of two or more heat resistant resin films (29a, 29b), the heat resistant resin films are preferably laminated with an adhesive layer interposed therebetween.

  The thickness of the outer layer 29 is preferably about 10 to 50 μm, and more preferably about 15 to 30 μm. When the thickness is 10 μm or more, the stretched film is sufficiently stretched when the plate-shaped body is molded, and the metal layer 30 is less likely to be necked. Therefore, the moldability of the plate-shaped body 28 is excellent. Moreover, if thickness is 50 micrometers or less, the effect of a moldability can fully be exhibited.

  For example, the outer layer 29 is a polyethylene terephthalate (PET) having a thickness of 1 to 10 μm in the case of one layer, and a PET (1 to 10 μm in thickness from the outermost layer in the case of two layers (29a, 29b) ( 29a), preferably made of ONy (29b) having a thickness of 1 to 15 μm.

  The metal layer 30 constituting the plate-like body 28 of the cases 2 and 12 plays a role of ensuring the barrier properties of the cases 2 and 12. As the metal layer 30, an aluminum foil, a stainless steel foil, a copper foil, or the like is preferably used. In consideration of formability, light weight, and cost, it is preferable to use an aluminum foil. As the material of the aluminum foil, a pure aluminum-based or aluminum-iron-based alloy O material (soft material) is preferably used.

  The thickness of the metal layer 30 is preferably 20 to 800 μm in order to ensure workability and to ensure barrier properties that prevent oxygen and moisture from entering the battery. More preferably, it is 40-60 micrometers. If the thickness is 20 μm or more, the metal foil is less likely to break during the molding of the cases 2 and 12, pinholes are less likely to occur, and oxygen and moisture can be prevented from entering. If the thickness is 60 μm or less, the effect of improving the breakage at the time of molding and the effect of preventing the occurrence of pinholes can be sufficiently exhibited, and the total thickness of the cases 2 and 12 does not become excessively thick. Increase in weight can be prevented.

  In addition, the metal layer 30 has an undercoat treatment such as a silane coupling agent or a titanium coupling agent, a chromate treatment, etc. in order to improve the adhesion between the outer layer 29 and the inner layer 31 or improve the corrosion resistance. It is good to have been subjected to chemical conversion treatment.

  Next, it is desirable that the inner layer 31 constituting the plate-like body 28 of the cases 2 and 12 includes a thermoplastic resin film. The thermoplastic resin film used for the inner layer 31 preferably has a heat sealing property and plays a role of improving chemical resistance against a highly corrosive electrolyte, such as polypropylene (PP), polyphenylene sulfide. An unstretched polyolefin film such as a resin (PPS) or maleic anhydride-modified polypropylene, or an unstretched film such as an ethylene-acrylate copolymer or an ionomer resin is preferably used.

  The thickness of the inner layer 31 is preferably in the range of 0.1 to 200 μm, and more preferably in the range of 50 to 100 μm. If the thickness is 0.1 μm or more, preferably 50 μm or more, the corrosion resistance to the electrolytic solution is more excellent, and if the thickness is 200 μm or less, preferably 100 μm or less, the chemical resistance effect can be sufficiently exhibited. And the weight increase of battery itself can be prevented.

  An adhesive layer (not shown) is provided between the outer layer 29 and the metal layer 30 and between the inner layer 31 and the metal layer 30 in order to bond the outer layer 29 and the metal layer 30 and the inner layer 31 and the metal layer 30 together. 30. When the outer layer 29 has a plurality of layers (29a, 29b), it is desirable that an adhesive layer be disposed between the layers. The adhesive layer is preferably a dry laminate adhesive layer. For example, it is desirable to use at least one selected from urethane, acid-modified polyolefin, styrene elastomer, acrylic, silicone, ether, and ethylene-vinyl acetate.

  The thickness of the adhesive layer is preferably in the range of 0.1 to 10 μm, and more preferably in the range of 1 to 5 μm. When the thickness of the adhesive layer is 1 μm or more, the adhesive strength is sufficient, and the insulation can be further improved. Further, if the thickness of the adhesive layer is 5 μm or less, further excellent adhesive strength can be realized.

  In particular, it is preferable to use adhesive layers made of different materials for the adhesive layer on the outer layer 29 side and the adhesive layer on the inner layer 31 side. By using adhesive layers made of different materials from each other, the adhesive strength between the materials and the resistance to electrolytic solution can be sufficiently imparted.

  The plate-like body can be produced by a known method in which the outer layer 29, the metal layer 30, and the inner layer 31 are laminated. For example, it can be formed into a film-like molded body using an extrusion molding machine, an injection molding machine, a calendar molding machine, an inflation molding machine, a roll molding machine, or a hot press molding machine.

  A more preferable laminated member as the plate-like body 28 constituting the cases 2 and 12 is one in which the outer layer 29 is composed of two layers composed of PET and ONy, the metal layer 30 is composed of aluminum, and the inner layer 31 is composed of PP. It is. A plate-like body 28 which is a laminate film adopting this configuration is commercially available and can be easily prepared.

  From the viewpoint of improving the rigidity, it is desirable that the outer layer 29 is PET, the metal layer 30 is aluminum, and the inner layer 31 is PP or PPS as a plate-like body constituting the cases 2 and 12. Here, it is desirable that the thickness of the metal layer 30 is 300 to 800 μm. By adopting this configuration, the cases 2 and 12 become more rigid. In the present specification, the plate-like body 28 having a metal layer 30 made of aluminum and having a thickness of 300 to 800 μm is referred to as a “thin aluminum laminate film”. Moreover, in this specification, when calling it the plate-shaped body 28, it shall mean both a laminate film and a thin-plate aluminum laminate film.

[ Reference form ]
A sealed battery module 1 according to a reference embodiment will be described below with reference to FIGS. 1 and 2. The above-described components are used for each component.

  The flat and rectangular electrode body 4 includes a positive electrode assembly 9a and a negative electrode assembly 9b that lead out electricity from the electrode body to the outside. The positive electrode assembly 9a is formed by extending and laminating a plurality of positive electrode current collectors in the electrode body 4, and the negative electrode assembly 9b is formed by extending and laminating a plurality of negative electrode current collectors in the electrode body 4. Is. The positive electrode assembly 9a and the negative electrode assembly 9b may be extended in opposite directions from the electrode body 4, or may be extended in parallel in the same direction.

  The plurality of electrode bodies 4 are arranged in a row and are electrically connected in series at the joint 5. Here, the joined portion 5 refers to a portion where joined bodies are joined together. For example, in the case of electrical connection in series, the junction 5 is configured by joining a positive electrode assembly 9a and a negative electrode assembly 9b. In the case of parallel connection, the joint portion is formed by joining positive electrode assemblies 9a or negative electrode assemblies 9b.

  When the electrode bodies 4 are electrically connected in series, the adjacent electrode bodies 4 are connected to each other through different joined bodies. For example, as shown in FIG. 1, electrode bodies 4 having a positive electrode assembly 9a and a negative electrode assembly 9b in opposite directions are arranged in a row. At this time, the plurality of electrode bodies 4 are arranged such that the positive electrode assemblies 9 a and the negative electrode assemblies 9 b of the electrode bodies 4 face the arrangement direction of the electrode bodies 4. And the adjacent electrode bodies 4 are electrically connected by a joined body having mutually different poles. Thus, an electrode body group electrically connected in series is prepared.

  Moreover, when the electrode bodies 4 are electrically connected in parallel, the electrode bodies 4 arranged in a row are connected by a joint of the same polarity. For example, the electrode body 4 is arranged in such a manner that the electrode bodies 4 having the positive electrode assembly 9a and the negative electrode assembly 9b in opposite directions are arranged in a row. At this time, the plurality of electrode bodies 4 are arranged so that the joined bodies of the respective electrode bodies 4 face in a direction orthogonal to the arrangement direction of the electrode bodies 4 and the poles of the joined bodies of the respective electrode bodies 4 face in the same direction. Established. Adjacent electrode bodies 4 are electrically connected to each other through, for example, electrode bodies having the same polarity. Thus, an electrode assembly group electrically connected in parallel is prepared.

It is desirable that the bonding in the bonding portion 5 is a bonding between bonded bodies, that is, a bonding between stacked current collectors. In general, the electrode bodies 4 are joined to each other by providing electrode terminals in the current collector laminated portion and joining the electrode terminals. Here, the step of joining the electrode terminals to the current collector laminate portion can be omitted by joining the current collector laminate portions without providing the electrode terminals in the current collector laminate portion. Therefore, the sealed battery module 1 of the said form can implement | achieve the simplification of a manufacturing process, the reduction of a number of parts, and the reduction of manufacturing cost. Although the joining method of each joined body is not specifically limited, For example, it is desirable to join each joined body by ultrasonic welding. Although details will be described later, it is also desirable to join the joint portion 5 integrally with the case when enclosing the electrode assembly in the case. Thereby, the sealed battery module 1 of the said form can implement | achieve further simplification of a manufacturing process and reduction of manufacturing cost.

  Each joined body may be electrically connected by providing electrode terminals and joining the electrode terminals together. By providing the electrode terminal on the joined body, the strength of the joined portion can be further improved. The method for providing the electrode terminals on the joined body and the method for joining the electrode terminals are not particularly limited, and known methods can be used. For example, they can be joined by spot welding, arc welding, laser welding, seam welding, ultrasonic welding, or the like.

  The electrode terminal is made of the same material as the joined body to be joined, that is, the current collector. For example, if it is an electrode terminal joined to the positive electrode assembly 9a, aluminum used in the positive electrode current collector can be adopted. If it is an electrode terminal joined to the negative electrode assembly 9b, copper used in the negative electrode current collector can be adopted.

  In the case of series connection, the electrode terminal at the junction 5 is preferably a clad material made of a material constituting the positive electrode current collector and the negative electrode current collector. For example, when the positive electrode current collector is made of aluminum and the negative electrode current collector is made of copper, a clad material made of aluminum and copper is employed. By adopting a clad material as the electrode terminal, the bonding process between the electrode terminals can be omitted. Therefore, the present invention can realize simplification of the manufacturing process, reduction in the number of parts, and reduction in manufacturing cost.

  Case 2 encloses the produced electrode body group together with the electrolytic solution. The external shape of the case is a shape that follows the external shape of the plurality of electrode bodies 4, that is, the electrode body group.

  The case 2 is preferably formed by deforming the plate-like body 28 composed of a pair of laminated members.

  One of the pair of laminated members is provided with the same number of concave storage spaces 3 as the number of electrode bodies 4 so that each of the electrode bodies 4 of the electrode body group can be accommodated. The method for producing the storage space 3 is not particularly limited. For example, the laminated member of the plate-like body 28 having a laminated structure as shown in FIG. 7 is produced by drawing into a shallow bowl (dish) by drawing. Is done. The storage spaces 3 are arranged in one laminated member in a line in a direction orthogonal to the thickness direction of the electrode body 4 to be stored. That is, one of the laminated members is a surface having a convex portion formed by the storage space 3 on one surface and a surface having an opening formed by the storage space 3 on the other surface. The other of the pair of laminated members is a plate-like body 28 that closes the other surface having one opening of the pair of laminated members.

  One of the produced laminated members sandwiches the electrode body group together with the electrolytic solution from the thickness direction of the electrode body 4 together with the laminated member of the other plate-like body 28. That is, each electrode body 4 is stored together with the electrolyte in each corresponding storage space 3.

  The pair of laminated members that house the electrode body group are sealed by a seal portion 8 that has an outer periphery sealing portion 6 that is an outer periphery thereof and an adjacent sealing portion 7 that is between adjacent storage spaces 3. . The seal portion 8 exists at a site isolated from the storage space 3. Here, the adjacent sealing portion 7 means a concave portion of the case 2 that exists between the storage spaces 3 in a direction in which the storage spaces 3 are arranged in a row. The adjacent sealing portion 7 has a joint portion 5 constituted by a joined body therein. FIG. 1 shows a part of the seal portion 8 composed of the outer peripheral sealing portion 6 and the adjacent sealing portion 7.

  In the adjacent sealing portion 7, it is desirable to provide a sealant 10 between the joint portion 5 and the laminated member, that is, between the both surfaces of the joint portion 5 facing the laminated member and the laminated member. The sealant 10 makes the electrolytic solution stored in the storage space 3 more effectively liquid-tight in order to improve the adhesion between the laminated member and the joint portion 5 made of metal. The material of the sealant 10 is not particularly limited, and a material composed of a known resin layer or a metal foil interposed between the resin layer can be used. For example, the laminated member side can be made of polyolefin resin, and the joint 5 side can be made of acid-modified polyolefin resin. Alternatively, the laminated member side can be made of a polyolefin resin, the joint portion side can be made of an acid-modified polyolefin resin, and a metal foil layer such as an aluminum foil can be provided therebetween.

  The sealing method is not particularly limited, and a known sealing means is used. For example, a heat seal method, an ultrasonic welding method, or the like is used.

  Here, in the case of electrical connection in series, it is desirable that the joint 5 existing inside the adjacent sealing portion 7 is joined by sealing the adjacent sealing portion 7. In this case, the joined body of each electrode body 4 is not joined at the time of producing the electrode body group. And each electrode body 4 is accommodated in each storage space 3 of case 2 with electrolyte solution in the state which joined each joined body of each electrode body 4 in the junction part. And in the sealing process of case 2, when sealing the adjacent sealing part 7, the junction part 5 is joined with sealing of a laminated member. That is, the joining part 5 is joined by the sealing means through the laminated member. According to this method, since the joining process of the joined body can be omitted in the process of producing the electrode body group, the manufacturing process can be further simplified and the manufacturing cost can be suppressed.

The shape of the sealed battery module 1 of the form manufactured in this way is a thin flat plate shape as a whole.

  In addition, it is desirable that the case 2 is formed by deforming the plate-like body 28 composed of a single laminated member. A part of the laminated member includes a storage space 3 having a number corresponding to the number of electrode bodies 4, and the remaining part is bonded to a part and sealed. That is, one of the pair of laminated members described above corresponds to a part, the other of the pair of laminated members corresponds to the remaining part, and the same configuration is adopted.

  The single laminated member stores the electrode group together with the electrolytic solution in the storage space 3 formed in a part, and then the remaining part is folded toward the opening of the part of the storage space 3 to close the storage space 3. And one laminated member is sealed by a well-known sealing means by the outer periphery sealing part 6 and the adjacent sealing part 7 between the storage spaces 3.

The sealed battery module 1 of the present embodiment seals between the storage spaces 3 of the case 2 in the sealing step. That is, since the case 2 of the said form seals and divides each storage space 3 independently, the electrolyte solution accommodated in each storage space 3 is liquid-tight. Thus, for example, when the electrode assembly 4 is electrically connected in series, since it is that each electrode assembly 4 to ensure a voltage having respectively, voltages sealed battery module 1 of the embodiment is equivalent to the number of electrode bodies 4 (Voltage of one electrode body × number of electrode bodies) can be obtained. Therefore, the desired voltage can be easily controlled.

Moreover, the sealed battery module 1 of the said form can produce a battery module simultaneously with producing a battery cell. That is, the battery cell case and the battery module case can be unified. Therefore, the manufacturing process can be simplified, the number of parts can be reduced, and the manufacturing cost can be suppressed.

[ Embodiment ]
The embodiment differs from the reference embodiment in terms of the electrode body arranging method. Therefore, description of the same points as the reference embodiment is omitted, and different points will be described below.

As shown in FIGS. 3, 4, 8, and 9, the sealed battery module 11 of the present embodiment deforms the partition plate 12 b and the plate body 28 that are the plate-like bodies 32 to change each of the electrode body groups. A case 12 is provided that includes an exterior body 12a that partitions a storage space 13 in which each of the electrode bodies 14 is stored together with an electrolytic solution.

  In the electrode body group composed of a plurality of electrode bodies 14, a part of the electrode body group is arranged in a row on one surface side of the partition plate 12b, and the rest of the electrode body group is placed in a row on the other surface side opposite to the one surface side. Arranged and configured. The arrangement direction of the electrode body 14 is a direction orthogonal to the longitudinal direction of the partition plate, that is, the thickness direction of the electrode body 14. The electrode body group configured as described above is enclosed together with the electrolyte solution by the exterior body 12a and the partition plate 12b, and the sealed battery module 11 according to the embodiment is formed.

  The partition plate 12 b is formed from a plate-like body 32. The plate-like body 32 has one side and the other side facing away from one side. That is, one surface and the other surface of the plate-like body 32 are front and back surfaces positioned in the front and back direction. A plurality of electrode bodies 14 are arranged in a row in the longitudinal direction on one surface and the other surface of the plate-like body 32. The front and back direction of the partition plate 12b coincides with the thickness direction of the electrode body 14. The longitudinal direction means a direction orthogonal to the thickness direction of the electrode body 14 (front and back direction of the partition plate).

The plate-like body 32 of the partition plate 12b insulates the electrode body 14 and the electrolyte disposed on both surfaces (one surface and the other surface) in an insulating manner. Therefore, from the viewpoint of improving chemical resistance against a highly corrosive electrolyte or the like, the plate-like body 32 is preferably a resin-coated metal plate on both sides. As shown in FIG. 8, the partition plate 12b is a laminated member formed by using a multilayer in which a resin layer 33, a metal layer 34, and a resin layer 33 are laminated in this order , or by laminating a plurality of multilayers .

The material of the laminated member (corresponding to a multilayer or plate-like body) constituting the partition plate 12b is not particularly limited, and the resin layer 33 can employ the resin employed in the above-described case, and the metal layer 34 can include the above-described metal layer 34. The metal used in the case can be used.

  The exterior body 12 a is formed by deforming the plate-like body 28. That is, the plate-shaped body 28 is formed so as to be deformed so as to provide a storage space 13 for storing each electrode body 4. The exterior body 12a may be a plate-like body 28 constituted by a pair of laminated members or a plate-like body 28 constituted by a single laminated member. The laminated member can employ the same configuration and material as the case described above.

The partition plate 12b is preferably formed using the same laminated member as the laminated member constituting the exterior body 12a. That is, as shown in FIG. 9, two identical laminate members (corresponding to a multilayer, a plate-like body, and a laminate) constituting the exterior body 12a are prepared, and the outer layers 29 (29a) of the laminate members are in contact with each other. It is desirable to form one plate-like body by arranging in such a manner. For example, when the laminated member employs a laminated film (corresponding to a laminated body) laminated in the order of PET, ONy, aluminum foil, and PP, the two laminated films are brought into contact with each other with the PET of the outermost layer 29 (29a). It arranges in. Therefore, the laminated member of the partition plate 12b to be manufactured adopts a configuration in which PP, aluminum foil, ONy, PET, ONy, aluminum foil, and PP are laminated in this order. In the partition plate 12b adopting this laminated structure, the layers positioned on both end faces are made of PP of thermoplastic resin, so that it is possible to improve the heat sealing property at the seal portion between the exterior body 12a and the partition plate 12b.

By forming the partition plate 12b in this manner, a plate member of the partition plate 12b and the exterior body 12a is prepared by preparing one kind of laminated member (corresponding to a multilayer, a plate-like body, and a laminate). be able to. Therefore, the sealed battery module 11 of the embodiment can further reduce the number of parts and the manufacturing cost.

In addition, a laminate member (corresponding to a multilayer, plate-like body, or laminate) of the partition plate 12b may be a commercially available laminate film bonded with PET, and the exterior body 12a may be a thin aluminum laminate film. By using a thin aluminum laminate film for the exterior body 12a, the rigidity of the sealed battery module 11 of the embodiment can be improved. And since the partition plate 12b can be prepared easily, a manufacturing process can be simplified more.

  The case 12 composed of the partition plate 12b and the exterior body 12a has a seal portion 18 that makes the storage space 13 liquid-tight. The seal part 18 includes an adjacent sealing part 17 positioned between the outer peripheral sealing part 16 positioned on the outer peripheral edge of the case and the adjacent storage spaces. FIG. 3 shows a part of the seal portion 18 including the outer peripheral sealing portion 16 and the adjacent sealing portion 17.

  As shown in FIG. 4, the inside of the adjacent sealing portion 17 includes a joining portion 15 that is a part of the electrode body group existing on one surface side of the partition plate 12 b and an electrode body existing on the other surface side of the partition plate 12 b. The joining portion 15 of the remaining group is thermocompression bonded by the exterior body 12a and the partition plate 12b. It is desirable to provide the sealant 20 between the exterior body 12a and the joint 15 and between the joint 15 and the partition plate 12b. As the sealant 20, the one described in the sealed battery module 1 according to the first embodiment can be adopted.

  Here, it is desirable that a part and the rest of the electrode body group are arranged in plane-symmetrical positions with the partition plate 12b as a symmetry plane. By disposing the electrode body 14 in this way, the adjacent sealing portions 17 on the one surface side and the other surface side of the partition plate 12b can also be disposed at opposing positions. Therefore, the sealing process of the adjacent sealing portion 17 can be performed at a time without separately performing the one surface side and the other surface side of the partition plate 12b. For example, if a heat sealing means is used as the sealing means, the adjacent sealing portion 17 can be sealed by applying heat seal bars from both the one side and the other side of the partition plate 12b.

  In addition, it is desirable that the joining portion 15 existing in the adjacent sealing portion 17 is arranged with a position shifted between the one surface side and the other surface side of the partition plate 12b. That is, in the planar perspective view of the adjacent sealing portion 17 as seen from the one surface side of the partition plate 12b, it is desirable that the joint portion 15 on the one surface side of the partition plate 12b and the joint portion 15 on the other surface do not overlap. By adopting this configuration, since the joint portions 15 existing on both surfaces of the partition plate 12b do not overlap, the thickness of the adjacent sealing portion 17 can be reduced. Therefore, the adjacent sealing part 17 can be sealed more efficiently. And the assembly | attachment property of the sealed battery module 11 of the said embodiment can be improved.

  In addition, it is desirable that the partition plate 12 b located in the adjacent sealing portion 17 is formed with a recess or a through hole that accommodates the joint portion 15. By providing a recess or a through hole in the partition plate 12b and housing the joint portion 15, the thickness of the adjacent sealing portion 17 can be further reduced. Therefore, the adjacent sealing part 17 can be sealed more efficiently. And the assembly | attachment property of the sealed battery module 11 of the said embodiment can be improved.

Next, the manufacturing method of the embodiment will be described with reference to FIGS. 6A to 6D, taking a series-connected sealed battery module as an example.

  The manufacturing method of the embodiment includes an electrode body group forming step (FIG. 6A), an electrode body group disposing step (FIG. 6B), a clamping step (FIG. 6C), and a sealing step (FIG. 6D).

  The electrode body group process is a process in which a plurality of electrode bodies 14 are arranged in a row and electrically connected in series at a plurality of joints 15 to form an electrode body group 27. The electrode bodies 14 are arranged in a line in the arrangement direction of the electrode bodies 14. Here, the arrangement direction means a direction orthogonal to the thickness direction of the electrode body 14.

  The positive electrode assembly 19a and the negative electrode assembly 19b of each electrode body 14 are located in the arrangement direction. The positive electrode assembly 19a and the negative electrode assembly 19b are located in directions opposite to each other.

  Adjacent electrode bodies 14 are electrically connected to each other at the joint 15 by joining a positive electrode assembly 19 a of one electrode body 14 and a negative electrode assembly 19 b of the other electrode body 14. The joining part 15 may be configured by providing an electrode terminal to each joined body and joining the electrode terminals.

  The number of electrode bodies 14 in the electrode body group 27 is desirably an even multiple of 2 or more. And the number of the junction parts 15 becomes the number of 2n-1 when the number of the electrode bodies 14 is 2n.

  When the number of electrode bodies 14 is an even multiple of two or more, the manufactured sealed battery module 11 according to the embodiment has a configuration in which the electrode bodies 14 are arranged at plane-symmetric positions with the partition plate 12b as a symmetry plane. Can be taken. A part and the remaining part of the electrode body group 27 are the same number, and a part and the remaining part of the electrode body group 27 are arranged in a plane-symmetrical position via the partition plate 12b, so that the joint 15 also passes through the partition plate 12b. It is arranged at a symmetrical position. Therefore, it is possible to seal two adjacent sealing portions 17 at a time from the front and back directions of the partition plate 12b in the sealing step.

The electrode body group disposing step is a step of disposing the electrode body group 27 so that one of the plurality of joint portions 15 is bent to sandwich the front and back surfaces of the partition plate 12b formed from a plate-like body. .

  In the electrode body group disposing step, first, one joint portion 15 in the prepared electrode body group 27 is bent into a mountain fold. That is, the shape of the electrode body 14 group is a U-shape in a vertical sectional view in the thickness direction of the electrode body 14.

  When the number of electrode bodies 14 in the electrode body group 27 is 2n, it is desirable that the joint 15 to be bent is positioned between the nth and n + 1th positions counted from the electrode bodies 14 at one end arranged in a row. By bending the joint 15 existing at this position, the electrode body 14 can be disposed at a plane-symmetrical position with the partition plate 12b as a symmetry plane.

  Next, in the vertical sectional view in the thickness direction of the electrode body 14, the partition plate 12b is provided between the electrode body groups 27 having a U-shape. The partition plate 12b has one surface as the front and back surfaces and the other surface in the front and back direction of the partition plate 12b. That is, part of the electrode body group 27 is disposed on one surface of the partition plate 12b so that the electrode body group 27 sandwiches the front and back surfaces of the partition plate 12b, and the rest of the electrode body group 27 is disposed on the other surface of the partition plate 12b. Arranged.

  The sandwiching process has a form following the outer shape of the electrode body group 27, and the electrode body group 27 is placed in the front and back direction of the partition plate 12b in the exterior body 12a that partitions the storage space 13 in which each electrode body 14 is stored together with the electrolyte. It is the process of pinching from.

  When the exterior body 12a is composed of a pair of laminated members, the pair of laminated members sandwich the electrode body group 27 from the front and back directions of the partition plate 12b. That is, one laminated member is fixed so as to sandwich the electrode body group 27 from the front direction of the partition plate 12b and the other laminated member from the back direction of the partition plate 12b, and each electrode body 14 is stored in the storage space 13. To do. Therefore, storage spaces 13 corresponding to the number of electrode bodies 14 stored in each stacked member are formed in both stacked members.

  When the exterior body 12a is composed of a single laminated member, the storage spaces 13 corresponding to the number of electrode body groups 27 are formed in a row in the longitudinal direction of the laminated member. Then, the laminated member is folded into a mountain fold at one adjacent sealing portion 17 so that each electrode body 14 is accommodated in the accommodating space 13. The laminated member folded in this way is fixed so as to sandwich the electrode body group 27 from the front and back directions of the partition plate 12b, and each electrode body 14 is stored in the storage space 13.

  The adjacent sealing portion 17 to be folded is counted from the other end of the laminated member and the storage space 13 located in the number corresponding to the number of electrode bodies 14 arranged on one surface of the partition plate 12b from one end of the laminated member. It is desirable that it is between the storage spaces 13 located in a number corresponding to the number of electrode bodies 14 provided on the other surface of the partition plate 12b.

  The sealing step is a step of making the adjacent storage spaces 13 liquid-tight.

  The storage space 13 is partitioned by the exterior body 12a and the partition plate 12b. The storage space 13 is sealed by a sealing process, and the stored electrolytic solution is liquid-tight. The sealing part 18 of the case 12 has the outer peripheral sealing part 16 and the adjacent sealing part 17 as described above, and is sealed by a known sealing means.

1: Sealed battery module according to reference embodiment 2, 12: Case 3, 13: Storage space 4, 14, 21: Electrode body 5, 15: Joint portion 6, 16: Outer peripheral edge sealing portion 7, 17: Adjacent seal stopping portion 8, 18: seal portion 9a, 19a, 25: cathode assembly 9b, 19b, 26: anode assemblies 10, 20: sealant 11: sealed battery module 12a according to the embodiment: exterior body 12b: partition plate 27 : Electrode group 28: Plate body (case, exterior body) 29: Outer layer 30: Metal layer 31: Inner layer 32: Plate body (partition plate) 33: Resin layer 34: Metal layer

Claims (7)

A plurality of flat-shaped electrode bodies (14) including a positive electrode element and a negative electrode element and electrically connected in series or in parallel at the joint (15);
A plate-like shape in which the thickness direction of the electrode body is aligned with the front and back direction of the electrode body, and a part of the plurality of electrode bodies are arranged in a row on the one surface side and the rest on the other surface side in a direction perpendicular to the thickness direction. A partition plate (12b) formed from a body (28), and a storage space (13) that is fixed so as to be sandwiched by the partition plate from the front and back sides and that stores the electrode bodies together with the electrolyte solution together with the partition plate A case (12) provided with an exterior body (12a) that is formed by deforming a plate-like body into a shape following the external shape of the electrode body,
Have
The partition plate is a laminated member formed by using a multilayer in which a resin layer (33), a metal layer (34), and a resin layer (33) are laminated in this order, or by laminating a plurality of the multilayers ( A sealed battery module (11) except for the one in which the multilayer is folded and stacked, and one in which the multilayer is bonded with an adhesive ). A part and the remainder of the plurality of electrode bodies are arranged in plane-symmetric positions with the partition plate as a symmetry plane,
In the plane perspective view which looked at the adjacent sealing part (17) located between the said adjacent storage spaces from the said one surface side of the said partition plate, the said junction part of the said one surface side and the said junction part of the said other surface side The sealed battery module according to claim 1 , wherein the positions of the sealed battery modules are shifted so as not to overlap each other. Having a seal portion (18) for liquid-tightening between adjacent storage spaces;
In the partition plate located in the adjacent sealing part (17) which is a part isolated from the storage space by the seal part of the case and located between the adjacent storage spaces, The sealed battery module according to claim 1, wherein a recess for housing the battery is formed. The electrode body has a positive electrode assembly (25, 19a) and a negative electrode assembly (26, 19b),
The sealed battery according to any one of claims 1 to 3 , wherein the electrode bodies are electrically connected in series by a clad material made of a material constituting the positive electrode assembly and the negative electrode assembly in the joint. module. The plate-like body (28) comprises outer layers (29), an inner layer (31), arranged metal layer between said outer layer and said inner layer (30),
The sealed battery module according to any one of claims 1 to 4 , wherein the outer layer is made of a heat resistant resin film, and the inner layer is made of a thermoplastic resin film. 6. The hermetic seal according to claim 5 , wherein the partition plate is formed by arranging two sheets of a laminate formed by laminating the outer layer, the metal layer (30), and the inner layer so that the outer layers are in contact with each other. Type battery module. An electrode body group forming step in which a plurality of electrode bodies are arranged in a row and electrically connected in series at a plurality of joints to form an electrode body group;
An electrode body group disposing step of disposing one of the plurality of joints to dispose the electrode body group so as to sandwich the front and back surfaces of the partition plate formed from a plate-like body ;
The electrode body group is formed by an exterior body that has a form following the outer shape of the electrode body group disposed in the electrode body group disposing step, and divides a storage space in which each electrode body is stored together with an electrolytic solution. A sandwiching step of sandwiching from the front and back direction of the partition plate,
After the sandwiching step, a sealing step for liquid-tightening the adjacent storage space;
And having
The partition plate is a laminated member formed by using a multilayer in which a resin layer (33), a metal layer (34), and a resin layer (33) are laminated in this order, or by laminating a plurality of the multilayers ( A method of manufacturing a sealed battery module, except for the one in which the multilayer is folded and stacked, and the one in which the multilayer is bonded with an adhesive .

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