JP2019160741A - Manufacturing method of laminated battery module - Google Patents

Abstract

To provide a manufacturing method of a laminated battery module that can improve assembly while avoiding an increase in weight and volume.SOLUTION: In a manufacturing method of a laminated battery module, after hydrophilic treatment is applied to at least one of a portion of a laminated battery cell 1 in contact with a heat conductive member 40 and a portion of the heat conductive member 40 in contact with the laminated battery cell 1, the laminated battery cell 1 and the heat conductive member 40 are pressed so as to be heated in an overlapped state to bond the laminated battery cell 1 and the heat conductive member 40.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for manufacturing a laminated battery module in which a plurality of laminated battery cells are arranged in a predetermined direction and are electrically connected.

  As one form of battery, a laminate type battery cell is known in which an electrode body is accommodated in a laminate film outer package. A laminate type battery module in which a plurality of laminate type battery cells are electrically connected is widely used as a high output power source for mounting on a vehicle. For example, Patent Document 1 includes a plurality of laminated battery cells arranged in series in the arrangement direction and connected in series, and a heat conducting member arranged between the laminated battery cells adjacent in the arrangement direction. A laminated battery module is disclosed.

JP 2014-212032 A

  In general, a laminate film outer package has a smooth surface and low friction. For this reason, when it is going to manufacture the above laminated battery modules combining a laminated battery cell, the position of the laminated battery cell with respect to a heat conductive member tends to shift | deviate, and an assembly is difficult. In other words, the laminate type battery module has poor assemblability. In order to improve the assemblability, for example, it is conceivable to fix the laminated battery cell to the heat conducting member using an adhesive tape or the like. However, in this method, there is a problem that the weight and volume of the module increase by the amount of the adhesive tape. For this reason, in manufacturing a laminate type battery module, a new technique for improving assembly while avoiding an increase in weight and volume has been demanded.

  This invention is made | formed in view of this situation, The objective is to provide the manufacturing method of the laminate type battery module which can improve assembly property, avoiding the increase in a weight and volume.

  According to the present invention, a laminate having a plurality of laminate-type battery cells arranged in the arrangement direction and electrically connected, and a heat conductive member arranged adjacent to the laminate-type battery cell in the arrangement direction. A method for manufacturing a battery module is provided. The manufacturing method includes the step of hydrophilizing at least one of the portion of the laminated battery cell that contacts the heat conductive member and the portion of the heat conductive member that contacts the laminated battery cell, It includes pressing the laminated battery cell and the heat conducting member while heating the laminated battery cell and the heat conducting member to join the laminated battery cell and the heat conducting member.

  In the above manufacturing method, the laminated battery cell and the heat conducting member are bonded to each other and physically integrated. As a result, the position of the laminate type battery cell is fixed with respect to the heat conducting member, and the position of the laminate type battery cell is difficult to shift. Moreover, in the said manufacturing method, the member (for example, adhesive tape) for fixing a heat conductive member to a laminate-type battery cell becomes unnecessary. Therefore, it is possible to improve assembly while avoiding an increase in the weight and volume of the module.

It is a side view which shows typically the external shape of the laminate type battery module which concerns on one Embodiment. It is principal part sectional drawing which shows typically the interface of a laminate film exterior body and a heat conductive member.

Hereinafter, a suitable embodiment of a manufacturing method indicated here is described, referring to drawings suitably. Note that matters other than matters specifically mentioned in the present specification and necessary for implementation can be grasped as design matters of those skilled in the art based on the prior art in this field. The manufacturing method disclosed here can be implemented based on the contents disclosed in the present specification and common general technical knowledge in the field.
Moreover, in the following drawings, the same code | symbol is attached | subjected to the member and site | part which show | plays the same effect | action, and the overlapping description may be abbreviate | omitted or simplified. The dimensional relationship (length, width, thickness, etc.) in each drawing does not necessarily reflect the actual dimensional relationship.
In addition, the notation “A to B (where A and B are arbitrary values)” indicating a range in the present specification means A or more and B or less.

  Here, the configuration of the laminate type battery module will be described first, and then the method for manufacturing the laminate type battery module according to one embodiment will be described.

<Laminated battery module>
FIG. 1 is a side view schematically showing the outer shape of a laminated battery module (hereinafter, simply referred to as “module”) 100 according to an embodiment. FIG. 2 is a main part cross-sectional view schematically showing an interface between the laminate film outer package 10 of the laminate type battery cell 1 and the heat conducting member 40. 2, illustration of the structure of the electrode body 20 is omitted. 1 and 2, the symbol X indicates the arrangement direction of the laminated battery cells 1.

The module 100 includes a plurality of laminated battery cells (hereinafter, simply referred to as “battery cells”) 1, a plurality of heat conducting members 40, a pair of end plates 50A and 50B, and a plurality of restraining bands 52. It is equipped with.
In the present specification, the “laminated battery cell” refers to all batteries having a configuration in which a laminate film is used as an exterior body and an electrode body is accommodated therein. The laminated battery cell may be, for example, a storage battery (secondary battery) such as a lithium ion secondary battery or a nickel metal hydride battery, or may be a storage element such as an electric double layer capacitor.

  Here, the plurality of battery cells 1 have the same shape. The plurality of battery cells 1 have a flat plate shape. Each of the plurality of battery cells 1 has a pair of flat wide surfaces, and is arranged along the arrangement direction X (the left-right direction in FIG. 1) so that the wide surfaces face the heat conducting member 40. Yes. The even-numbered battery cells 1 in the arrangement direction X are arranged in a state rotated by 180 ° with respect to the odd-numbered battery cells 1 in the arrangement direction X. In addition, although the battery cell 1 which comprises the module 100 is five here, it is not limited to this. The number of battery cells 1 constituting the module 100 may typically be 10 or more, for example, about 10 to 100.

  A positive electrode terminal 1 a and a negative electrode terminal 1 b protrude from the outer surface of each battery cell 1. The positive electrode terminal 1 a and the negative electrode terminal 1 b extend from the inside of the laminate film outer package 10 to the outside. Here, the positive electrode terminal 1a and the negative electrode terminal 1b of the battery cell 1 adjacent to each other in the arrangement direction X are electrically connected. Thus, the plurality of battery cells 1 are connected in series.

  The configuration of the battery cell 1 may be the same as the conventional one, and is not particularly limited. The battery cell 1 is an all-solid battery here. The battery cell 1 includes a laminate film exterior body 10 and an electrode body 20 accommodated in the laminate film exterior body 10. The laminate film outer package 10 has a bag shape and is sealed by heat-sealing (heat-sealing) the periphery of the housing space for housing the electrode body 20.

  The laminate film exterior body 10 is an insulating container that houses the electrode body 20. The configuration of the laminate film exterior body 10 may be the same as that conventionally known and is not particularly limited. The laminate film outer package 10 is typically composed of a laminate film having a multilayer structure. The laminate film outer package 10 of the present embodiment has a three-layer structure, and is configured by laminating a sealant layer 11, a gas barrier layer 12, and a protective layer (outer layer) 13 in this order from the side close to the electrode body 20. ing.

  The sealant layer 11 is a layer for enabling heat welding. The sealant layer 11 is located on the innermost layer of the laminate film exterior body 10, that is, on the side closest to the electrode body 20. The sealant layer 11 is made of, for example, a thermoplastic resin. Examples of the thermoplastic resin include crystalline resins such as polyolefins such as polyethylene (PE) and polypropylene (PP); polyesters such as polyethylene terephthalate (PET); and amorphous resins such as polystyrene and polyvinyl chloride. It is done. Among these, from the viewpoint of exhibiting the effects of the technology disclosed herein at a higher level, a crystalline resin, particularly polyolefin is preferable.

  The gas barrier layer 12 is a layer that blocks moisture and air or gas generated inside or outside the battery cell 1 from entering or leaving the battery cell 1. The gas barrier layer 12 is made of, for example, a metal material such as aluminum, iron, or stainless steel. Of these, aluminum is preferable from the viewpoint of cost and weight reduction. The gas barrier layer 12 may be, for example, an aluminum foil or an aluminum vapor deposition layer.

  The protective layer 13 is a layer for improving the durability of the laminate film outer package 10. The protective layer 13 is located on the outer surface side of the gas barrier layer 12. The protective layer 13 may be the outermost layer of the laminate film outer package 10. The protective layer 13 is made of, for example, polyester such as PET, polyamide (nylon), or the like.

  In the present embodiment, as an example, the case where the laminate film outer package 10 has a three-layer structure including the sealant layer 11, the gas barrier layer 12, and the protective layer 13 has been described. However, the multilayer structure of the laminate film outer package 10 may be four layers or more, for example, 4 to 10 layers. As an example, an adhesive layer for adhering both layers may be provided between the above-described layers. The adhesive layer may be made of a resin such as polyamide (nylon). As another example, a printed layer, a flame retardant layer, a surface protective layer, or the like may be further provided on the protective layer 13 as an outermost layer, for example.

  The electrode body 20 includes a positive electrode, a negative electrode, and a solid electrolyte layer (not shown). The solid electrolyte layer is interposed between the positive electrode and the negative electrode in the arrangement direction X. The configuration of the electrode body 20 may be the same as that conventionally known and is not particularly limited. The electrode body 20 is typically a stacked electrode body (laminated electrode body) in which a rectangular positive electrode and a rectangular negative electrode are stacked in the arrangement direction X via a solid electrolyte layer. However, the electrode body 20 may be a wound electrode body (rolled electrode body) in which a strip-shaped positive electrode and a strip-shaped negative electrode are stacked via a solid electrolyte layer and wound in the longitudinal direction. . The electrode body 20 may further include a layer such as an insulating layer on the surface of the positive electrode and / or the negative electrode, for example.

  The positive electrode may include a positive electrode current collector and a positive electrode active material layer fixed to the positive electrode current collector. The positive electrode current collector is a conductive member made of a metal having good conductivity, such as aluminum. The positive electrode active material layer includes at least a positive electrode active material capable of reversibly occluding and releasing charge carriers. The positive electrode active material is a lithium transition metal composite oxide such as lithium nickel cobalt manganese composite oxide. The positive electrode active material layer may further contain other components such as a solid electrolyte material, a conductive material, and a binder described later.

  The negative electrode may include a negative electrode current collector and a negative electrode active material layer fixed to the negative electrode current collector. The negative electrode current collector is a conductive member made of a metal having good conductivity, such as copper. The negative electrode active material layer includes at least a negative electrode active material capable of reversibly occluding and releasing charge carriers. The negative electrode active material is a carbon material such as graphite. The negative electrode active material layer may further contain other components, for example, a solid electrolyte material described later, a binder, a thickener, and the like.

The solid electrolyte layer includes a solid electrolyte material having ion conductivity. The solid electrolyte material may be crystalline or amorphous (glassy). When the battery cell 1 is a lithium ion secondary battery, the solid electrolyte layer contains a solid electrolyte material having Li ion conductivity. Examples of the solid electrolyte material having Li ion conductivity include sulfide-based solid electrolytes such as Li ₂ S—P ₂ S ₅ and Li ₂ S—SiS ₂ , La _0.51 Li _0.34 TiO _{2. 94} , Li _1.3 Al _0.3 Ti _1.7 (PO ₄ ) _{3 and} other oxide-based solid electrolytes.

  In addition, in this embodiment, the case where the battery cell 1 was an all-solid-state battery was demonstrated as an example. However, the battery cell 1 may be a liquid secondary battery having a liquid electrolyte (electrolytic solution), for example. In that case, the electrode body 20 may have a configuration in which the positive electrode and the negative electrode are opposed to each other via an insulating member such as a separator. In addition to the electrode body 20, an electrolytic solution may be accommodated in the laminate film exterior body 10. The electrolytic solution may contain, for example, a nonaqueous solvent such as carbonates and esters and a supporting salt such as a lithium salt that generates a charge carrier.

  The heat conducting member 40 is a member for cooling and / or heating the battery cell 1 in order to use the battery cell 1 at an appropriate temperature. The heat conducting member 40 functions as a heat radiating plate for dissipating heat generated inside the battery cell 1 during charge / discharge, for example. Here, the plurality of heat conducting members 40 have the same shape. The plurality of heat conducting members 40 have a flat plate shape. Each of the plurality of heat conducting members 40 has a pair of flat wide surfaces, and the wide surfaces are disposed so as to face the battery cell 1 or the end plates 50A and 50B. In other words, the plurality of heat conducting members 40 are arranged in the arrangement direction X between the plurality of battery cells 1 and between the battery cell 1 and the end plates 50A and 50B, respectively. The configuration of the heat conducting member 40 may be the same as that conventionally known and is not particularly limited. The heat conducting member 40 is made of, for example, a resin material such as polypropylene (PP) or polyphenylene sulfide (PPS), or a metal material having good heat conductivity. The heat conducting member 40 may have, for example, a plurality of groove portions that can be used as flow paths for cooling fluid (typically air) on the surface facing the battery cell 1.

  The pair of end plates 50A and 50B are arranged at both ends of the module 100 in the arrangement direction X (left and right direction in FIG. 1). The end plates 50A and 50B sandwich the plurality of battery cells 1 and the plurality of heat conducting members 40 in the arrangement direction X. The plurality of restraint bands 52 are fixed to the end plates 50 </ b> A and 50 </ b> B by a plurality of screws 54. Each of the plurality of restraining bands 52 is attached so that a prescribed restraining pressure is applied in the arrangement direction X. As a result, a load is applied to the plurality of battery cells 1 and the plurality of heat conducting members 40 from the arrangement direction X, and the modules 100 are integrally held. In the present embodiment, the plurality of battery cells 1 are constrained by the end plates 50A and 50B, the plurality of restraining bands 52, and the plurality of screws 54. However, the restraining mechanism is not limited to this.

As shown in FIG. 2, in the module 100 of this embodiment, the hydrophilic portion 13a is formed on the surface of the protective layer 13 which is the outermost layer of the laminate film outer package 10 here, in contact with the heat conducting member 40 of the battery cell 1. Is provided. And the battery cell 1 and the heat conductive member 40 are joined via the hydrophilic part 13a. Thereby, the battery cell 1 and the heat conductive member 40 are physically integrated. In other words, the battery cell 1 and the heat conducting member 40 are a joined body. In the present specification, “joining” means having an integrity that does not drop when the plate is turned upside down.
Hereinafter, a method for manufacturing such a module 100 will be described.

<Method for producing laminated battery module>
In the manufacturing method disclosed herein, the battery cell 1 is subjected to a hydrophilization treatment on at least one of a portion in contact with the heat conductive member 40 and a portion of the heat conductive member 40 in contact with the battery cell 1. The battery cell 1 and the heat conducting member 40 are joined by pressing while heating the cell 1 and the heat conducting member 40 in an overlapped state. Other than this, a conventional general construction process can be adopted as appropriate. The manufacturing method of this embodiment includes the following three steps: (1) a preparation step for preparing the battery cell 1 and the heat conducting member 40; (2) a hydrophilic treatment step for hydrophilizing the surface of the battery cell 1; (3) a heating and pressing step of pressing the battery cell 1 and the heat conducting member 40 while heating. In addition to these steps, it is not impeded that other steps are included at any stage. Hereinafter, each process is demonstrated in order.

  (1) In the preparation step, the battery cell 1 and the heat conducting member 40 are prepared. The battery cell 1 can be produced by housing the electrode body 20 inside the laminate film outer package 10 and then sealing the periphery of the housing space housing the electrode body 20 by heat welding (heat sealing). it can. The laminate film outer package 10 can be prepared, for example, by purchasing a commercially available product. The electrode body 20 is, for example, the following step: a step of coating a positive electrode slurry containing a positive electrode active material, a solid electrolyte material, and a solvent on a positive electrode current collector foil, and drying to prepare a positive electrode; negative electrode active material Coating a negative electrode slurry containing a solid electrolyte material and a solvent on a negative electrode current collector foil, followed by drying to prepare a negative electrode; a solid is formed on the surface of the positive electrode and / or negative electrode or carrier sheet prepared above. Producing by a manufacturing method comprising: forming a solid electrolyte layer containing an electrolyte material; laminating the positive electrode and the negative electrode with the solid electrolyte layer interposed therebetween, and pressing and pressing from the laminating direction. can do.

  (2) In the hydrophilization treatment step, the surface of the battery cell 1 on the side in contact with the heat conducting member 40, specifically, the surface of the protective layer 13 of the laminate film outer package 10 is hydrophilized. In the present specification, “hydrophilic treatment” refers to all treatments for improving the hydrophilicity by modifying the surface of the protective layer 13. That is, it means a treatment in which the hydrophilicity of the protective layer 13 is increased by performing the treatment compared to before the treatment. The hydrophilization treatment is a chemical treatment in which, for example, an oxygen-containing group containing oxygen (O) such as a hydroxyl group or a carboxyl group is introduced into the surface of the protective layer 13. The hydrophilicity of the protective layer 13 can be grasped by, for example, the static contact angle (wetting property) of water.

  In this step, the region (range) to be subjected to the hydrophilic treatment is set so as to include a region in contact with the heat conducting member 40 in the heating and pressing step described later. The region where the hydrophilic treatment is performed may be set to be equal to or greater than the surface area of the wide surface of the heat conducting member 40. However, the surface area of the wide surface of the heat conducting member 40 may be set smaller. In plan view, the hydrophilization treatment may be performed, for example, on the entire surface of the protective layer 13 or may have the same size as the surface area of the wide surface of the heat conducting member 40. The hydrophilization treatment may be performed continuously on the surface of the protective layer 13 or may be performed discontinuously like a dot shape or a stripe shape.

The method of hydrophilic treatment may be the same as that conventionally known and is not particularly limited. In the hydrophilization treatment, for example, oxygen species (O ₂ ), ozone (O ₃ ), oxide ions (O ²⁻ ), oxygen radicals, oxygen plasma, and other chemical species including oxygen are supplied to the surface of the protective layer 13. It is a process including that. Specific examples of the hydrophilic treatment include corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, and ozone treatment. Of these, the corona discharge treatment is simple and preferable.

The corona discharge treatment can be performed using, for example, a general corona discharge treatment apparatus such as a spark gap method, a vacuum tube method, or a solid state method. In an example of the corona discharge treatment apparatus, a voltage is applied between the discharge electrode and the grounded counter electrode dielectric roll to generate corona discharge. The conditions for the corona discharge treatment may be appropriately adjusted so that desired hydrophilicity is imparted to the surface of the protective layer 13, and is not particularly limited. As an example may the corona discharge density, generally well set to 5~50W ^/ m 2 ^/ min, for example, ^{10 ± 5W / m 2 / min} . Further, the processing time can be generally within 10 minutes, typically within 5 minutes, for example, 0.1 second to 1 minute, from the viewpoint of productivity and cost.
As described above, the hydrophilic portion 13a can be formed by applying a hydrophilic treatment to the surface of the battery cell 1, here the surface of the protective layer 13 of the laminate film outer package 10.

(3) In the heating and pressing step, first, the laminate film exterior body 10 of the battery cell 1 is opposed to the heat conduction member 40 and the laminate film exterior body 10 and the heat conduction member 40 are overlapped. At this time, the hydrophilic portion 13 a of the laminate film outer package 10 is disposed so as to contact the heat conducting member 40. Next, while the battery cell 1 and the heat conducting member 40 are heated, the battery cell 1 and the heat conducting member 40 are pressed from the direction in which the battery cell 1 and the heat conducting member 40 are overlapped (the same as the X direction in FIG. 2). The conditions for heating and pressing may be adjusted as appropriate so that the battery cell 1 and the heat conducting member 40 are joined to each other, and are not particularly limited. As an example, the heating temperature may be approximately 40 ° C. or higher, typically 40-80 ° C., for example 60 ± 10 ° C. Moreover, the pressure (pressing pressure) at the time of pressing can be about 5 MPa or more, typically 10 to 100 MPa, for example, 30 ± 10 MPa.
As described above, the battery cell 1 and the heat conducting member 40 can be joined to obtain a joined body in which these are physically integrated. In addition, the joined body may be in a form in which only one wide surface of the battery cell 1 is subjected to a hydrophilization treatment and one heat conductive member 40 is joined, and each of the wide surfaces on both sides of the battery cell 1 is joined. It may be a form in which two heat conducting members 40 are joined by applying a hydrophilic treatment.

  Then, typically, after the steps (1) to (3) are repeated a plurality of times to produce a plurality of the joined bodies, they are sandwiched between the end plates 50A and 50B from the arrangement direction X, and a plurality of restraining bands 52 are formed. And a plurality of screws 54. As described above, the module 100 having the plurality of laminate type battery cells 1 arranged in the arrangement direction X and the heat conduction member 40 arranged at a position adjacent to the laminate type battery cell 1 in the arrangement direction X. Can be produced.

  Thus, in the said manufacturing method, after forming the hydrophilic part 13a in the protective layer 13, the battery cell 1 and the heat conductive member 40 are joined through the said hydrophilic part 13a, and are physically integrated. This eliminates the need for an adhesive tape or an adhesive for fixing the heat conducting member 40 to the battery cell 1. Therefore, it is possible to improve assembly while avoiding an increase in the weight and volume of the module 100. As a result, the productivity of the module 100 can be increased and the production cost can be reduced. Further, the module 100 can be reduced in weight or space, and battery characteristics (for example, battery capacity) per unit weight or per unit volume can be improved. Furthermore, in the state of the module 100, even when vibration or impact is applied from the outside, the positional deviation between the battery cell 1 and the heat conducting member 40 can be suppressed and high durability can be realized.

  The module 100 can be used for various applications, but can be suitably used as, for example, a power source (drive power source) for a motor mounted on a vehicle. The type of the vehicle is not particularly limited, but typically includes an automobile such as a plug-in hybrid automobile (PHV), a hybrid automobile (HV), and an electric automobile (EV).

  As mentioned above, although this invention was demonstrated in detail, the said embodiment is only an illustration and what changed and modified the above-mentioned specific example is included in the invention disclosed here.

  For example, in the above-described embodiment, (2) in the hydrophilization treatment step, the surface of the battery cell 1 on the side in contact with the heat conductive member 40, specifically, the surface of the protective layer 13 of the laminate film outer package 10 is hydrophilized. I was going to give. However, it is not limited to this. In the technique disclosed herein, the hydrophilization treatment may be performed on at least one of a portion of the battery cell 1 that contacts the heat conductive member 40 and a portion of the heat conductive member 40 that contacts the battery cell 1. For example, the portion of the heat conducting member 40 that contacts the battery cell 1 may be subjected to a hydrophilic treatment.

1 Laminated battery cell (battery cell)
DESCRIPTION OF SYMBOLS 10 Laminate film exterior body 13 Protective layer 13a Hydrophilic part 40 Thermal conductive member 100 Laminated battery module (module)

Claims (1)

A laminate-type battery module comprising: a plurality of laminate-type battery cells arranged in an arrangement direction and electrically connected; and a heat conductive member arranged adjacent to the laminate-type battery cell in the arrangement direction. A manufacturing method comprising:
After applying a hydrophilic treatment to at least one of a portion of the laminate type battery cell that contacts the heat conductive member and a portion of the heat conductive member that contacts the laminate type battery cell, Including pressing the heat conductive member in a state where the heat conductive member is overlaid and joining the laminated battery cell and the heat conductive member.
A method for manufacturing a laminate-type battery module.

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