JP5954258B2 - Battery pack and manufacturing method thereof - Google Patents

Description

  The present invention relates to a battery pack that is an assembly of a plurality of stacked battery cells and a method for manufacturing the battery pack.

  In the conventional battery pack described in Patent Document 1, a plurality of flat battery cells electrically connected in series are stacked, and an intermediate member having high thermal conductivity is sandwiched between the stacked battery cells. The cooling plate has a cooling plate that is in thermal contact with the battery cell to cool the battery cell. The intermediate member is a cooling plate that cools the surface in contact with the battery cell by the refrigerant flowing through the inside.

JP 2012-33306 A

  However, in the battery pack as in Patent Document 1, the dimensions of the outer case of each battery cell may vary. Since the battery pack is integrally formed by stacking a plurality of battery cells and applying a binding force to the battery cells, if there is a dimensional difference between the battery cells, the adhesion between the cooling plate and each battery cell Cannot be secured. In particular, when the variation in the height dimension of the battery cell is large, the contact area between the battery case and the cooling plate varies, or the contact state varies. Thus, in the conventional battery pack, there is a problem that the heat generation of the battery cell is not sufficiently transferred to the cooling plate, and the cooling performance of the battery cell cannot be obtained.

  Therefore, the present invention has been made in view of the above problems, and its purpose is to reduce the thermal resistance existing between the battery cells and the cooler and to ensure the battery cooling performance and the manufacture thereof. Is to provide a method.

  The present invention employs the following technical means to achieve the above object. It should be noted that the reference numerals in parentheses described in the claims and in this section indicate the correspondence with the specific means described in the embodiments described later as one aspect, and the technical scope of the present invention It is not limited.

One of the inventions related to the disclosed battery pack is that a plurality of battery cells (3) arranged in a stacked manner, a main body part in which heat transfer is performed between the heat medium and the main body, and the main body A cooler (5) configured to have a cooling plate (50) provided so as to conduct heat with the intermediate portion, and an intermediate member (4; 104; 204; 304; 404; 504), and
The intermediate member is in contact with the outer main wall (31) of the battery cell forming a surface orthogonal to the thickness direction (X) of the battery cell, and is sandwiched between the adjacent battery cells from both sides, and the cooling member A fitting piece (42; 142; 242; 342; 442; 542) that fits into a through hole (51; 151; 251; 351; 451) formed in the plate, and along the thickness direction from the end of the main wall It is an extended shape and is a member which has a side wall part (41) which contacts a cooling plate, It is characterized by the above-mentioned.

  According to this invention, with the fitting piece of the intermediate member fitted in the through hole of the cooling plate, the side wall portion of the intermediate member contacts the cooling plate, and the main wall portion of the intermediate member is sandwiched between the battery cells from both sides. It has a unique configuration. According to this configuration, a compressive force acts on the main wall portion of the intermediate member in the thickness direction in a state where the fitting piece is temporarily fixed to the cooling plate. This action causes a force to press the side wall portion against the cooling plate as the main wall portion is displaced in the direction in which the compressive force acts. That is, according to the specific configuration, it is possible to obtain both the adhesion between the side wall portion of the intermediate member and the cooling plate and the adhesion between the main wall portion of the intermediate member and the exterior main wall of the battery cell. A battery pack capable of ensuring the cooling performance of the battery can be provided.

One of the inventions related to the disclosed battery pack is a cooler (505; in which heat transfer is performed between a plurality of battery cells (3) arranged in a stacked manner and the heat medium by contacting the heat medium. 605; 705), and an intermediate member (604) having thermal conductivity and interposed between the battery cells stacked and arranged,
The intermediate member has a main wall portion (640) that contacts the exterior main wall (31) of the battery cell that forms a surface orthogonal to the thickness direction (X) of the battery cell and is sandwiched between the adjacent battery cells from both sides. ,
The cooler is provided between the fitting recess (5500) into which the one end (6460) of the main wall fits and the fitting recess aligned in the thickness direction, and is a deformed portion deformed in the thickness direction or in a direction intersecting the thickness direction. (5501), and
The fitting recess is characterized in that one end portion of the main wall portion is gripped with the deformation of the deformation portion.

  According to this invention, due to the deformation of the deformation portion, the fitting recess of the cooler grips and fixes one end portion of the main wall portion of the intermediate member, and the main wall portion of the intermediate member is sandwiched between the battery cells from both sides. It has a unique configuration. According to this configuration, the heat transfer between the main wall portion and the cooling plate can be ensured by the gripping structure of the one end portion of the main wall portion by the fitting recess. That is, according to the specific configuration, it is possible to acquire both heat transfer properties between the main wall portion of the intermediate member and the cooling plate, and adhesion between the main wall portion of the intermediate member and the exterior main wall of the battery cell. A battery pack that can ensure sufficient battery cooling performance can be provided.

One of the inventions related to the disclosed method for manufacturing a battery pack is a main body portion in which heat transfer is performed between a plurality of battery cells (3) arranged in a stacked manner and the heat medium by contacting the heat medium. And a cooler (50) having a cooling plate (50, 150, 250, 350; 450) provided so as to conduct heat with the main body, and interposed between the battery cells having heat conductivity and being stacked. A main wall portion (40) that is an intermediate member that forms a surface orthogonal to the thickness direction (X) of the battery cell, and a wall portion that extends from an end portion of the main wall portion and has an angle of 90 degrees with the main wall portion in advance. And an intermediate member (4; 104; 204) comprising a side wall (41) having an angle greater than, and a fitting piece (42; 142; 242; 342; 442; 542) extending from the end of the main wall. 304; 404; 504); A method of manufacturing a battery pack, including,
The assembly process is
A through hole formed in the cooling plate while the main wall portion of the intermediate member is opposed to the outer main wall (31) of the battery cell that forms a surface orthogonal to the thickness direction, and the side wall portion of the intermediate member and the cooling plate are brought into contact with each other. (51; 151; 251; 351; 451), the fitting piece is fitted, and the battery cell and the intermediate member are laminated in the thickness direction,
The laminate (2; 102; 202; 302; 402; 502) including a plurality of battery cells and an intermediate member is subjected to a compressive force in the thickness direction to exceed 90 degrees formed by the main wall portion and the side wall portion. The intermediate member is deformed so that the angle is reduced, and the battery plate and the intermediate member are brought into close contact with each other, and the cooling plate and the side wall of the intermediate member are brought into close contact with each other.

  According to this invention, the assembly process of applying a compressive force in the thickness direction to the main wall portion of the intermediate member is performed in a state where the fitting piece of the intermediate member is fitted in the through hole of the cooling plate. Since the intermediate member is set to a member whose angle between the main wall portion and the side wall portion exceeds 90 degrees in advance, the fitting piece fits into the through hole of the cooling plate before the compressive force is applied to the laminate. The side wall portion and the cooling plate are in contact with each other, and the main wall portion is inclined with respect to a virtual plane orthogonal to the thickness direction.

  When a compressive force is applied to the laminate from this state, the fitting piece is temporarily fixed to the cooling plate in the thickness direction of the battery cell, so the main wall portion is a fulcrum at the connection portion with the side wall portion. As shown in FIG. That is, the compressive force in the thickness direction acting on the main wall portion causes the angle between the main wall portion and the side wall portion to approach 90 degrees, and a force that presses the side wall portion against the cooling plate by such deformation of the intermediate member works. It becomes like this.

  Therefore, according to the execution of this assembly process, it is possible to obtain both the adhesion between the side wall portion of the intermediate member and the cooling plate and the adhesion between the main wall portion of the intermediate member and the exterior main wall of the battery cell. It is possible to provide a battery pack capable of ensuring a sufficient battery cooling performance.

It is a disassembled perspective view which shows the structure of the battery pack which concerns on 1st Embodiment of this invention. In the manufacturing process of the battery pack of 1st Embodiment, it is a front view which shows the state before making compressive force act on a battery assembly. In the manufacturing process of the battery pack of 1st Embodiment, it is a perspective view which shows the state after making compressive force act on a battery assembly. It is the elements on larger scale which show the relationship between the intermediate member and cooling plate in the state of FIG. In FIG. 4, it is the elements on larger scale which show the fitting state of the angle which a side wall part and a main wall part make, and a fitting piece and a cooling plate. In the manufacturing process of the battery pack of 2nd Embodiment, it is a front view which shows the state before making compressive force act on a battery assembly. In the manufacturing process of the battery pack of 2nd Embodiment, it is the elements on larger scale which show the state after making compressive force act on a battery assembly. In FIG. 7, it is the elements on larger scale which show the contact state of a side wall part and a cooling plate, and the fitting state of a fitting piece and a cooling plate. It is a disassembled perspective view which shows the structure of the battery pack which concerns on 3rd Embodiment. It is a perspective view which shows the procedure which assembles | attaches a fitting piece to a cooling plate in the manufacturing process of the battery pack of 3rd Embodiment. In the manufacturing process of the battery pack of 3rd Embodiment, it is a front view which shows the state before making compressive force act on a battery assembly. In the manufacturing process of the battery pack of 3rd Embodiment, it is the elements on larger scale which show the state after making compressive force act on a battery assembly. It is a disassembled perspective view which shows the structure of the battery pack which concerns on 4th Embodiment. In the battery pack of 4th Embodiment, it is a partial expansion perspective view which shows the fitting state of a fitting piece and a cooling plate. It is the elements on larger scale which show the direction which bends a fitting piece in the manufacturing process of the battery pack of 4th Embodiment. It is a perspective view which shows the procedure which assembles | attaches a fitting piece to a cooling plate in the manufacturing process of the battery pack of 5th Embodiment. It is a perspective view which shows the 1st other form with respect to the battery pack of 5th Embodiment. In the manufacturing process of the battery pack of 6th Embodiment, it is a partial cross section figure which shows the state before making compressive force act on a cooler. FIG. 19 is a partial cross-sectional view for explaining that a compressive force is applied to the cooler after the spacers and the battery cells are installed from the state illustrated in FIG. 18. It is a partial cross section figure showing the 1st other form to the battery pack of a 6th embodiment. It is a partial cross section figure showing the 2nd other form to the battery pack of a 6th embodiment.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also combinations of the embodiments even if they are not specified, unless there is a particular problem with the combination. Is also possible.

(First embodiment)
A battery pack 1 according to an embodiment of the present invention includes a hybrid vehicle that uses, for example, an internal combustion engine and a motor driven by electric power charged in a battery as a travel drive source, and an electric that uses a motor as a travel drive source. Used in automobiles. The some battery cell 3 which comprises the battery pack 1 is a nickel-hydrogen secondary battery, a lithium ion secondary battery, and an organic radical battery, for example.

  A first embodiment will be described with reference to FIGS. In each figure, the thickness direction X of the battery cell 3 is also a stacking direction in which a plurality of battery cells 3 and intermediate members 4 are stacked.

  The battery pack 1 is controlled by electronic components (not shown) used for charging and discharging of a plurality of battery cells 3 or temperature adjustment. In addition, the battery pack 1 may be configured by integrating a plurality of battery cells 3 that are electrically connected in series and stacked, and may be housed in a housing, for example. The electronic components are, for example, a DC / DC converter, a motor that drives a blower member, electronic components controlled by an inverter, various electronic control devices, and the like, and are adjusted by, for example, a power element that is a switching power supply device It is a part operated by electric power.

  Further, in the battery pack 1, the cooler 5 is cooled by receiving a heat medium supplied by a heat medium transport device (not shown), whereby the heat of the battery cell 3 is absorbed through the intermediate member 4, and each battery Cell 3 is cooled. Various fluids can be adopted as the heat medium, and for example, air, water, or a refrigerant can be used. When the heat medium is a refrigerant, the refrigerant flowing through the refrigeration cycle can be used.

  The case is, for example, a rectangular parallelepiped case configured so that at least one surface can be removed for maintenance, and is formed of a resin or a steel plate. The housing may be provided with an attachment portion for fixing the housing to the vehicle side by bolting or the like, and an equipment storage box. In the equipment box, a battery monitoring unit to which detection results such as voltage and temperature from various sensors are input, and control that is communicable with the unit and that controls the power transfer of the DC / DC converter and the drive of the heat transfer device. The device and a wire harness for connecting each device are accommodated. The battery monitoring unit is an electronic control unit for a battery that monitors the state of each battery cell 3, and is connected to the battery pack 1 by a number of wires.

  Next, the structure which concerns on the constraining structure of the some battery cell 3 is demonstrated. As shown in FIG. 1, the battery pack 1 includes a plurality of battery cells 3, an intermediate member 4 interposed between the battery cells 3, a cooler 5 that is cooled by contact with a heat medium, and a set of end plates 6. , And four restraining members 7 that provide a compressive force to the end plate 6.

  Each battery cell 3 is a flat rectangular parallelepiped whose outer peripheral surface is covered with an outer case of an electrically insulating resin. In each battery cell 3, two electrode terminals 30, which are a positive electrode terminal and a negative electrode terminal, protrude from each of two opposing surfaces of the outer case, and this protruding direction is relative to the thickness direction X of the battery cell 3. Vertical direction. The outer case of the battery cell 3 is formed of, for example, any resin or metal having an insulating property. In the case of resin, for example, polypropylene, polyethylene, polystyrene, vinyl chloride, fluorine resin, PBT, polyamide, polyamideimide, ABS resin, polyacetal, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, phenol, epoxy, acrylic Or the like. Or the film which laminated these resin etc. and aluminum foil can be used as an exterior case.

  The pair of end plates 6 are plate-like members provided on both sides of the laminate 2 including the battery cells 3 and the intermediate members 4 that are alternately laminated. One set of end plates 6 includes four inner plates 61 and 63 and outer plates 60 and 62 arranged on both sides of the laminate 2. The inner plate 61 and the inner plate 63 are plates that are in direct contact with the laminate 2 and sandwiched from both sides. The outer plate 60 is a plate that is provided outside the inner plate 61 and applies a compressive force to the laminate 2 integrally with the inner plate 61. The outer plate 62 is a plate that is provided outside the inner plate 63 and applies a compressive force to the laminate 2 integrally with the inner plate 63.

  The restraining member 7 is a rod-like member having a shaft portion longer than the length dimension in the thickness direction X in which the laminated body 2 and the pair of end plates 6 are combined. The restraining member 7 is formed of a material having excellent strength, such as a metal or a hard resin, so that the plurality of stacked battery cells 3 can be pressed and integrated with a stable force.

  The restraint member 7 has a bolt part 70 at one end and a male screw part 71 having a predetermined length at the other end. In the assembly process of the laminated body 2, each restraining member 7 is inserted through the shaft portions thereof into insertion holes 600, 610, 620, and 630 provided at the four corners of the pair of end plates 6, and each of the intermediate members 4. It is inserted into each insertion hole 43 provided at the four corners of the main wall portion 40. The insertion hole 43 is provided in the main wall portion 40 at a position corresponding to the insertion holes 600, 610, 620, and 630.

  When each of the restraining members 7 is inserted into the insertion holes 600, 610, 620, and 630 and the insertion holes 43, the nuts 72 that are screwed into the male screw parts 71 are tightened, and the distance between the bolt part 70 and the nut 72 is increased. And the laminate 2 is sandwiched from both sides by a pair of end plates 6. In this way, in the assembly process of the laminate 2, the compressive force by the four restraining members 7 acts on the laminate 2.

  Further, the outer plate 60 and the inner plate 61 located on one side of the laminate 2 are fixed together with the cooling plate 50 by two bolts 64 inserted into two mounting holes 52 provided in the cooling plate 50. Is done. Accordingly, the outer plate 60 and the inner plate 61 do not move even when the compressive force of the four restraining members 7 acts, and the outer plate 62 and the inner plate 63 located on the other side are not moved. It moves in the thickness direction X with respect to the plate 61. Due to the movement of the outer plate 62 and the inner plate 63, the laminate 2 is pushed and moved in the thickness direction X to come into contact with the outer plate 60 and the inner plate 61 on one side, and further, the compressive force from the pair of end plates 6 And is restrained.

  The cooler 5 is a device that is made of a material having excellent thermal conductivity, and heat transfer is performed between the cooler 5 and the heat medium by contacting the heat medium. The cooler 5 includes a main body (not shown) in which heat transfer is performed between the heat medium and the cooling medium 50 provided to conduct heat with the main body. Is done. The cooling plate 50 and the main body may be a single component, or may be configured to be assembled together so that another component can conduct heat. The cooler 5 is connected to the intermediate member 4 via the cooling plate 50 and is configured to be capable of heat transfer with the intermediate member 4.

  As shown in FIG. 2, the intermediate member 4 is a member that is made of a material having excellent thermal conductivity and is interposed between the battery cells 3 that are stacked in the thickness direction X. The intermediate member 4 is a tray that has a vertical cross-sectional shape as a whole and is held so that the battery cell 3 is accommodated in a concave portion having a U-shape. The intermediate member 4 is configured by integrally including a main wall portion 40, a fitting piece 42, and a side wall portion 41. The battery cell 3 is covered with a side wall 41 extending from the lower end of the main wall 40 and another side wall extending from the upper end of the main wall 40 so that the electrode terminal 30 extends along the side wall 41. The intermediate member 4 is held in a posture that protrudes laterally. Therefore, the height of the main wall portion 40 of the intermediate member 4 is slightly longer than the height of the outer case of the battery cell 3, and the lateral width of the intermediate member 4, that is, the length of the side wall portion 41, is the electrode terminal 30 of the battery cell 3. It is set to be equal to or slightly longer than the length including.

  As shown in FIG. 5, the angle θ formed by the main wall portion 40 and the side wall portion 41 is set in advance to an angle exceeding 90 degrees, that is, an angle larger than a right angle. Therefore, in a state where the side wall 41 is grounded to the cooling plate 50 before the compressive force by the four restraining members 7 is applied, the main wall 40 is in other words, with respect to a virtual plane orthogonal to the thickness direction X. If it does, it will be in the state inclined with respect to the surface perpendicular | vertical with respect to the cooling plate 50 (refer FIG. 2, FIG. 4).

  As shown in FIG. 3, the main wall portion 40 is in contact with the exterior main wall 31 of the battery cell 3 that forms a surface orthogonal to the thickness direction X, and is sandwiched between the adjacent battery cells 3 from both sides. The exterior main wall 31 of the battery cell 3 is in close contact with the main wall portion 40 of the intermediate member 4 and receives a pressing force on the entire surface. The side wall portion 41 contacts the cooling plate in a shape extending along the thickness direction X from the end portion of the main wall portion 40 in the assembled product.

  The main wall portion 40 is a vertical wall portion having a flat surface extending in the upward direction, and the entirety of the main wall portion 40 is in contact with the exterior main wall 31 which is a facing surface of the adjacent battery cells 3. The main wall portion 40 has four insertion holes 43 that are a total of four through holes at four corners that do not overlap the stacked battery cells 3.

  The fitting piece 42 is a claw portion that is fitted into the through hole 51 formed in the cooling plate 50 when the intermediate member 4 is assembled to the cooler 5. Three fitting pieces 42 are provided in the intermediate member 4 at a predetermined interval in the width direction of the side wall 41 (direction in which the electrode terminal 30 protrudes). Each fitting piece 42 protrudes from the end of the main wall 40 downward (on the cooler 5 side) to be equal to or larger than the thickness of the side wall 41 and the thickness of the cooling plate 50, and the main wall 40 is an L-shaped piece protruding from the end of 40 in the thickness direction X in the same manner as the side wall 41. Therefore, as shown in FIGS. 2, 4, and 5, each of the L-shaped fitting pieces 42 has a side wall portion 41 in a state before the end portion is fitted into the through hole 51 of the cooling plate 50. Has a shape extending from the end of the main wall 40, that is, in the same direction as the thickness direction X. Moreover, since each fitting piece 42 is such a shape, it can be formed by raising the side wall part 41 partially in an L shape downward.

  Moreover, when the battery cell 3 is comprised with the lithium ion secondary battery, the said secondary battery has an electrolyte and other required members which are interposed between a positive electrode, a negative electrode, these positive and negative electrodes. Hereinafter, each element will be described.

(Positive electrode)
As an active material of the positive electrode included in the lithium ion secondary battery, it is desirable to use a polyanionic material. The polyanionic substance is a compound having a chemical formula represented by LiMPO ₄ or Li ₂ MSiO ₄ , and M is preferably at least one metal element selected from Mn, Fe, Co, and Ni. By using such a positive electrode active material, when a situation such as an abnormal increase in internal pressure occurs in the battery cell 3, it is possible to suppress the chain occurrence of this situation.

  Other elements that can be included include a conductive material, a binder, and a current collector. The positive electrode active material can form an active material layer formed in layers on the surface of the current collector in a state of being mixed with a conductive material, a binder, and the like. For example, the positive electrode active material, the binder, the conductive material, and the like can be formed by mixing them in a solvent such as water or N-methyl-2-pyrrolidone (NMP) and then applying the mixture on the current collector.

  The conductive material is a material that transmits and receives electrons generated from the active material, and may be any material that has conductivity. Examples thereof include a carbon material and a conductive polymer material. As the carbon material, ketjen black, acetylene black, carbon black, graphite, carbon nanotube, amorphous carbon and the like can be adopted. Further, polyaniline, polypyrrole, polythiophene, polyacetylene, or polyacene can be used as the conductive polymer material.

  The binder is a material that forms an electrode by combining components such as an active material. Various polymer materials can be adopted, and those having high chemical and physical stability are desirable. Examples thereof include polyvinylidene fluoride, polytetrafluoroethylene, ethylene propylene rubber (EPDM), styrene butadiene rubber (SBR), nitrile rubber (NBR), and fluorine rubber. Further, when a conductive polymer material is employed as the conductive material, the action of the binder can be expressed in addition to the action of the conductive material. The current collector may be a metal foil formed from a metal such as aluminum.

(Negative electrode)
Although the structure of a negative electrode is not specifically limited, It can have a suitable negative electrode active material. Depending on the type of the negative electrode active material, a binder or a current collector may be used. The binder can be the same as that described for the positive electrode. The current collector may be a metal foil formed of a metal such as copper. As the negative electrode active material, compounds capable of inserting and extracting lithium ions can be used alone or in combination. Examples of compounds capable of inserting and extracting lithium ions include metal materials such as lithium, alloy materials containing silicon, tin, copper and the like, carbon materials such as graphite and coke, and titanium oxide.

(Electrolytes)
The electrolyte is a medium for transporting charge carriers such as ions between the positive electrode and the negative electrode. Although not particularly limited, the electrolyte is physically, chemically, and electrically stable in an atmosphere in which a lithium ion secondary battery is used. Is desirable.

(Other necessary components)
As other necessary members, a separator, a case, an electrode terminal, and the like are selected according to the configuration and usage of the secondary battery.

  It is desirable to interpose a separator that is a member that achieves both electrical insulation and ion conduction between the positive electrode and the negative electrode. When the electrolyte is liquid, the separator also serves to hold the liquid electrolyte. As the separator, a porous synthetic resin film, in particular, a porous film made of polyolefin polymer (polyethylene, polypropylene) or glass fiber, or a nonwoven fabric can be employed.

  The positive electrode, the negative electrode, the electrolyte, the separator, and the like are accommodated in the outer case. This exterior case is not particularly limited, and can be made of various materials and forms. The exterior case is provided with an electrode terminal 30 that transmits and receives electric power inside and outside the case.

  According to the above embodiment, the battery pack 1 includes the cooler 5 configured to include the plurality of battery cells 3 and the cooling plate 50 provided to conduct heat with the main body portion in contact with the heat medium. An intermediate member 4 having thermal conductivity and interposed between the battery cells 3. The intermediate member 4 includes a main wall 40 that is sandwiched between adjacent battery cells 3, a fitting piece 42 that fits into a through hole 51 formed in the cooling plate 50, and a thickness direction from the end of the main wall 40. And a side wall 41 that contacts the cooling plate 50 and extends along X.

  According to this configuration, the cooling plate 50 is locked in a state where the fitting piece 42 is fitted in the through hole 51 of the cooling plate 50, the side wall portion 41 contacts the cooling plate 50, and the main wall portion 40 is connected to the battery from both sides. It is sandwiched between the cells 3. Accordingly, the main wall portion 40 is sandwiched between the battery cells 3 in a state where the fitting piece 42 is fitted in the through hole 51. That is, a compressive force can be applied to the main wall portion 40 in the thickness direction X in a state where the fitting piece 42 is temporarily fixed to the cooling plate 50. Therefore, when the main wall portion 40 is pushed in the thickness direction X, the side wall portion 41 exhibits a reaction force close to a certain kind of spring force, and the side wall portion 41 is pressed against the cooling plate 50 with the fitting piece 42 as a fulcrum. The applied force is increased. As the external force in the thickness direction X acting on the main wall portion 40 increases, the side wall portion 41 is more strongly pressed against the cooling plate 50.

  That is, according to this unique configuration, the battery pack 1 that can acquire both the adhesion between the side wall 41 and the cooling plate 50 and the adhesion between the main wall 40 and the exterior main wall 31 of the battery cell 3. A structure is obtained, and sufficient battery cooling performance can be ensured.

  Further, in the assembled product, the end portion of the fitting piece 42 extending so as to penetrate the through hole 51 is in contact with the cooling plate 50 on the back surface with respect to the surface of the cooling plate 50 with which the side wall portion 41 is in contact. According to this, since the structure which pinches | interposes the cooling plate 50 with the fitting piece 42 and the side wall part 41 is realizable, the structure in which the fitting piece 42 locks the cooling plate 50 can be strengthened, In the process of applying a compressive force, It is possible to suppress escape of force that causes the side wall portion 41 and the cooling plate 50 to closely contact each other. That is, according to this unique configuration, the adhesion between the side wall portion 41 and the cooling plate 50 can be more reliably obtained, and sufficient battery cooling performance can be ensured.

  Further, in the assembled product, the front end portion of the fitting piece 42 extends in the same direction as the side wall portion 41 extends from the end portion of the main wall portion 40, and the surface of the cooling plate 50 with which the side wall portion 41 contacts. Then, it contacts the cooling plate 50 on the back surface. According to this, since the extending direction of the fitting piece 42 and the side wall portion 41 is the same direction, the operation of fitting the fitting piece 42 into the through hole 51 and the side wall portion 41 are slid with respect to the cooling plate 50. It is easy to perform the operation of grounding at the same time. Therefore, a structure that facilitates the assembly process of the battery pack 1 can be provided.

  The battery pack 1 includes a set of end plates 6 that apply a compressive force to the plurality of battery cells 3 and the intermediate member 4 from both sides in the thickness direction X. According to this configuration, by applying a compressive force to the pair of end plates 6, the main wall portion 40 is sandwiched by the battery cells 3 from both sides, and the cooling plate 50 is locked by the fitting piece 42, and the side wall portion The number of steps required for the step of bringing 41 into contact with the cooling plate 50 can be reduced.

  In the battery pack 1, the battery cell 3 and the intermediate member 4 are stacked in the thickness direction X in a state where at least one surface of the exterior main wall 31 is in contact with the main wall portion 40 of the intermediate member. According to this structure, the heat dissipation function by the intermediate member 4 can be provided for each battery cell 3 included in the battery pack 1, and the cooling performance of the battery pack 1 can be enhanced.

  The manufacturing method of the battery pack 1 assembles a plurality of battery cells 3, a cooler 5 in which heat transfer is performed between the heat medium via the cooling plate 50, and an intermediate member 4 interposed between the battery cells. Includes assembly process. The intermediate member 4 includes a main wall portion 40, a wall portion extending from an end portion of the main wall portion 40, and a side wall portion 41 having an angle with the main wall portion 40 that exceeds 90 degrees in advance, and the main wall portion 40. A fitting piece 42 extending from the end is provided.

  In the assembly process, the main wall portion 40 is opposed to the exterior main wall 31 of the battery cell 3 that forms a surface orthogonal to the thickness direction, the side wall portion 41 and the cooling plate 50 are brought into contact with each other, and the through hole 51 of the cooling plate 50 is provided. The fitting piece 42 is fitted to the battery cell 3 and the battery cell 3 and the intermediate member 4 are laminated in the thickness direction X. Further, in this state, an angle exceeding 90 degrees formed by the main wall portion 40 and the side wall portion 41 is caused by applying a compressive force in the thickness direction X to the stacked body 2 including the plurality of battery cells 3 and the intermediate member 4. The intermediate member 4 is deformed to be smaller. Thereby, the battery cell 3 and the intermediate member 4 are brought into close contact with the cooling plate 50 and the side wall 41 at the same time.

  According to this manufacturing method, the assembly step of applying a compressive force to the main wall portion 41 in the thickness direction X in a state where the fitting piece 42 is fitted in the through hole 51 of the cooling plate 50 and the cooling plate 50 is locked. carry out. The intermediate member 4 used in this manufacturing method is formed in advance in a shape in which the angle formed by the main wall portion 40 and the side wall portion 41 exceeds 90 degrees. For this reason, before the compressive force is applied to the laminate 2, the fitting piece 42 is fitted into the through hole 51, the side wall 41 and the cooling plate 50 are in contact with each other, and the virtual plane orthogonal to the thickness direction X The main wall 40 is tilted. That is, as shown in FIG. 4 and FIG. 5, the main wall portion 40 is in a posture slightly tilted to the side where the compressive force is applied.

  When compressive force is applied to the laminate 2 of the battery cell 3 and the intermediate member 4 from this state, the fitting piece 42 is temporarily fixed to the cooling plate 50 in the thickness direction X. The connecting portion with the side wall portion 41 is used as a fulcrum so that the inclination with respect to the virtual plane is reduced. That is, due to the compressive force in the thickness direction X acting on the main wall portion 40, the angle formed between the main wall portion 40 and the side wall portion 41 is reduced from the angle before assembly to approach 90 degrees, and the intermediate member 4 is deformed to form the side wall. The force which presses the part 41 against the cooling plate 50 comes to work. At this time, when the main wall portion 40 is pushed in the thickness direction X, the side wall portion 41 exhibits a reaction force close to a certain kind of spring force, and the side wall portion 41 is connected to the side wall portion 41 or the fitting piece 42 as a fulcrum. The acting force by which the portion 41 is pressed against the cooling plate 50 is increased. As the external force in the thickness direction X acting on the main wall portion 40 increases, the side wall portion 41 is more strongly pressed against the cooling plate 50.

  Therefore, according to this assembling process, the battery pack 1 that can obtain both the adhesion between the side wall 41 and the cooling plate 50 and the adhesion between the main wall 40 and the exterior main wall 31 of the battery cell 3 is obtained. And sufficient battery cooling performance can be ensured.

  Further, the fitting piece 42 used in the manufacturing method of the battery pack 1 has a shape bent with respect to the main wall portion 40 in a state before being fitted into the through hole 51. According to this, since the fitting piece 42 has a shape bent with respect to the main wall portion 40 in advance, the fitting piece 42 is fitted in the through hole 51 in the thickness direction X with respect to the stacked body 2. When the compressive force is applied, the locking function of the cooling plate 50 by the fitting piece 42 is easily exhibited at the initial stage. Therefore, the structure in which the fitting piece 42 locks the cooling plate 50 can be reliably strengthened, and the escape of the force that closely contacts the side wall 41 and the cooling plate 50 can be suppressed in the process of applying the compressive force.

  The manufacturing method of the battery pack 1 performs the following steps in the assembly process. A rod-like restraining member 7 having a bolt portion 70 at one end and a male screw portion 71 at the other end passes through a pair of end plates 6 and the main wall portion 40 provided on both sides of the laminate. The nut 72 that has been inserted and screwed into the male screw portion 71 is tightened. By moving the end plate 6 in the thickness direction X by tightening the nut 72, a compressive force is applied to the stacked body 2 to bring the battery cell 3 and the intermediate member 4 into close contact with each other.

  According to this process, the main wall 40 is sandwiched between the battery cells 3 and the cooling plate 50 is locked by the fitting pieces 42 by applying a compressive force to the pair of end plates 6 by tightening the nuts 72. The number of steps for contacting the side wall 41 with the cooling plate 50 can be reduced.

(Second Embodiment)
In 2nd Embodiment, a battery pack provided with the laminated body 102 which is another form of 1st Embodiment is demonstrated with reference to FIGS. In each figure, the same components as those in the first embodiment are denoted by the same reference numerals and have the same operations and effects.

  The laminated body 102 is different from the laminated body 2 of the first embodiment in that an intermediate member 104 of another form is provided. The configuration, assembly process, operation, and effect not particularly described in the second embodiment are the same as those in the first embodiment. Only differences from the first embodiment will be described below.

  The intermediate member 104 is configured by integrally including the main wall portion 40, the fitting piece 142, and the side wall portion 41. The fitting piece 142 is a claw portion that is fitted into the through hole 51 formed in the cooling plate 50 when the intermediate member 104 is assembled to the cooler 5. Three fitting pieces 142 are provided in the intermediate member 104 at a predetermined interval in the width direction of the side wall 41 (direction in which the electrode terminal 30 protrudes).

  Each fitting piece 142 protrudes from the end of the main wall 40 downward (on the cooler 5 side) to be equal to or larger than the thickness of the side wall 41 and the thickness of the cooling plate 50, and the main wall 40 is an L-shaped piece protruding from the end of 40 in the direction opposite to the thickness direction X and in the direction opposite to the side wall 41. Therefore, as illustrated in FIGS. 6 to 8, each of the L-shaped fitting pieces 142 has an end portion before fitting into the through hole 51 of the cooling plate 50, and the side wall portion 41 is the main wall. The direction extending from the end of the portion 40, that is, the shape extending in the direction opposite to the thickness direction X is formed. Moreover, since each fitting piece 142 is such a shape, it can be formed by raising the side wall part 41 partially in an L shape downward.

  As described above, in the assembled product, the front end of the fitting piece 142 extends in a direction opposite to the direction in which the side wall 41 extends from the end of the main wall 40, and the cooling plate 50 with which the side wall 41 contacts. It contacts the cooling plate 50 on the back surface with respect to the surface.

  According to this, since the extending direction of the fitting piece 142 and the side wall portion 41 is the reverse direction, the fitting piece 142 is fitted in the through hole 51 and the side wall portion 41 is grounded to the cooling plate 50. When a compressive force is applied to the laminate 2, a contact portion that extends over a long distance in the thickness direction X can be formed. That is, the portion where the front end portion of the fitting piece 142 contacts the back surface of the cooling plate 50 is located on the opposite side to the portion where the side wall portion 41 contacts the cooling plate 50, so these portions are on the same side. The holding function of the cooling plate 50 by the intermediate member 104 can be reliably improved as compared with some cases.

  Further, as shown in FIG. 6, the front end portion of the fitting piece 142 extends in the same direction as the direction in which the main wall portion 40 is inclined before the compression force is applied to the stacked body 102. According to this configuration, when the main wall portion 40 is raised by applying a compressive force to the laminate 102, a reaction force that strongly pushes the front end portion of the fitting piece 142 against the back surface of the cooling plate 50 is applied. . For this reason, the holding function of the cooling plate 50 by the fitting piece 142 can be further improved.

(Third embodiment)
In 3rd Embodiment, a battery pack provided with the laminated body 202 which is the other form of 1st Embodiment is demonstrated with reference to FIGS. In each figure, the same components as those in the first embodiment are denoted by the same reference numerals and have the same operations and effects.

  The laminated body 202 is different from the laminated body 2 of the first embodiment in that an intermediate member 204 of another form is provided. The configuration, assembly process, operation, and effect not particularly described in the third embodiment are the same as those in the first embodiment. Only differences from the first embodiment will be described below.

  The intermediate member 204 is configured by integrally including the main wall portion 40, the fitting piece 242, and the side wall portion 41. The fitting piece 242 is a claw portion that is fitted into the through hole 151 formed in the cooling plate 150 when the intermediate member 204 is assembled to the cooler 5. Three fitting pieces 242 are provided in the intermediate member 204 at a predetermined interval in the width direction of the side wall 41 (direction in which the electrode terminal 30 protrudes).

  As shown in FIG. 10, each fitting piece 242 is a T-shaped piece that protrudes downward (on the cooler 150 side) from the end of the main wall portion 40. The fitting piece 242 is provided in the width direction of the side wall portion 41 (the direction in which the electrode terminal 30 protrudes), a root portion 2421 having a narrow width, and a lower portion away from the end portion of the main wall portion 40 than the root portion 2421. The front end portion 2420 having a width wider than that of the root portion 2421 is integrally formed. Moreover, since each fitting piece 242 is such a shape, it can be formed by raising the side wall part 41 partially in a T shape downward.

  The through-hole 151 is a convex opening formed by a narrow narrow mouth portion 1510 and an enlarged mouth portion 1511 wider than the narrow mouth portion 1510. The through holes 151 are formed so as to be arranged in the thickness direction X in the order of the enlarged mouth portion 1511 and the narrow mouth portion 1510.

  When fitting the fitting piece 242 into the through hole 151, first, the fitting piece 242 is inserted into the enlarged opening portion 1511 and deeply inserted to the root portion 2421. In this way, all the fitting pieces 242 are fitted in the corresponding through holes 151 and all the side wall portions 41 are grounded to the cooling plate 150, and a compressive force is applied to the laminate 202. Along with the action of the compressive force, the main wall portion 40 is raised from the inclined state and the intermediate member 204 is pushed in the thickness direction X, so that the position of the root portion 2421 of the fitting piece 242 is the enlarged mouth portion. It moves so that it may displace from 1511 to the narrow mouth part 1510 side. At this time, the front end portion 2420 comes into contact with the cooling plate 50 on the back surface of the cooling plate 50, whereby the fitting piece 242 is locked to the cooling plate 150, the side wall portion 41 comes into contact with the cooling plate 150, and the main wall The part 40 is sandwiched between the battery cells 3 from both sides.

  Accordingly, the main wall portion 40 is sandwiched between the battery cells 3 in a state where the fitting piece 242 is fitted in the through hole 151. That is, the compression force can be applied to the main wall portion 40 in the thickness direction X in a state where the fitting piece 242 is temporarily fixed to the cooling plate 150. Therefore, when the main wall portion 40 is pushed in the thickness direction X, the side wall portion 41 exhibits a reaction force close to a certain kind of spring force, and the side wall portion 41 is pressed against the cooling plate 150 with the fitting piece 242 as a fulcrum. The applied force is increased. As the external force acting on the main wall 40 in the thickness direction X increases, the side wall 41 is more strongly pressed against the cooling plate 150.

  That is, according to this unique configuration, the structure of the battery pack that can acquire both the adhesion between the side wall 41 and the cooling plate 150 and the adhesion between the main wall 40 and the exterior main wall 31 of the battery cell 3. And sufficient battery cooling performance can be ensured.

(Fourth embodiment)
In the fourth embodiment, a battery pack including a laminate 302, which is another form of the first embodiment, will be described with reference to FIGS. In each figure, the same components as those in the first embodiment are denoted by the same reference numerals and have the same operations and effects. In FIG. 14, a state in which the cooling plate 250 is intentionally broken is illustrated in order to facilitate understanding of the fitting state of the fitting piece 342 and the through hole 251.

  The laminated body 302 is different from the laminated body 2 of the first embodiment in that an intermediate member 304 of another form is provided. The configuration, assembly process, operation, and effect not particularly described in the fourth embodiment are the same as those in the first embodiment. Only differences from the first embodiment will be described below.

  The intermediate member 304 is configured by integrally including the main wall portion 40, the fitting piece 342, and the side wall portion 41. The fitting piece 342 is a claw portion that is fitted into the through hole 251 formed in the cooling plate 250 when the intermediate member 304 is assembled to the cooler 5. Two fitting pieces 342 are provided in the intermediate member 304 at a predetermined interval in the width direction of the side wall 41 (direction in which the electrode terminal 30 protrudes).

  As shown in FIG. 14, each fitting piece 342 is an L-shaped piece that protrudes downward (on the cooler 250 side) from the end of the main wall 40. The fitting piece 342 is provided at a base portion 3421 having a shorter length in the thickness direction X and below the end portion of the main wall portion 40 than the base portion 3421, and is longer in the thickness direction X than the base portion 3421. Is formed integrally with a long tip portion 3420. The distal end portion 3420 has a shape protruding in the thickness direction X from the root portion 3421. Moreover, since each fitting piece 342 is such a shape, it can be formed by raising the side wall part 41 partially in an L shape downward.

  The through hole 251 is an opening formed in a narrow rectangular shape. The width dimension of the through hole 251 is set larger than the thickness dimension of the fitting piece 342. The length dimension of the through hole 251 in the thickness direction X is set to be larger than the length dimension of the distal end portion 3420 in the thickness direction X.

  When fitting the fitting piece 342 into the through hole 251, first, the fitting piece 342 is inserted into the through hole 251 and deeply inserted to the root portion 3421. Further, as shown in FIG. 14, the fitting piece 342 is moved in the direction opposite to the thickness direction X to a position where the tip portion 3420 can contact the back surface of the cooling plate 250. In this way, each intermediate member 304 is moved until the positional relationship between the fitting piece 342 and the through hole 251 becomes as shown in FIG.

  With such a positional relationship between the fitting piece 342 and the through hole 251, a compressive force is applied to the laminate 302 in a state where the side wall 41 is grounded to the cooling plate 250. Along with the action of the compressive force, the main wall portion 40 is raised from the inclined state, and the intermediate member 304 is pushed in the thickness direction X. As a result, the front end portion 3420 is pressed against the cooling plate 50 on the back surface of the cooling plate 50, so that the fitting piece 342 locks the cooling plate 250, the side wall portion 41 contacts the cooling plate 250, and the main wall The part 40 is sandwiched between the battery cells 3 from both sides.

  Thus, the main wall 40 is sandwiched between the battery cells 3 with the fitting piece 342 fitted in the through hole 251. That is, a compressive force can be applied to the main wall portion 40 in the thickness direction X in a state where the fitting piece 342 is temporarily fixed to the cooling plate 250. Therefore, when the main wall portion 40 is pushed in the thickness direction X, the side wall portion 41 exhibits a reaction force close to a certain kind of spring force, and the side wall portion with the connection portion between the side wall portion 41 and the main wall portion 40 as a fulcrum. The acting force with which 41 is pressed against the cooling plate 250 is increased. As the external force in the thickness direction X acting on the main wall portion 40 increases, the side wall portion 41 is more strongly pressed against the cooling plate 250.

  That is, according to this unique configuration, the structure of the battery pack that can acquire both the adhesion between the side wall 41 and the cooling plate 250 and the adhesion between the main wall 40 and the exterior main wall 31 of the battery cell 3. And sufficient battery cooling performance can be ensured.

  Further, in the assembly process, the end portion (tip portion 3420) of the fitting piece is further fitted so that the cooling plate 250 comes into contact with the surface of the cooling plate 250 with which the side wall portion 41 comes into contact. You may make it perform the process of bending the piece 342 (refer FIG. 15). The bending direction can be the direction in which the electrode terminal 30 protrudes. According to this process, since the fitting piece 342 can provide a configuration that can reliably exhibit the function of locking the cooling plate 250, the side wall 41 is cooled by using the connection portion between the side wall 41 and the main wall 40 as a fulcrum. The acting force pressed against the plate 250 can be increased.

(Fifth embodiment)
In the fifth embodiment, a battery pack including stacked bodies 402 and 502 that are other forms of the first embodiment will be described with reference to FIGS. 16 and 17. In each figure, the same components as those in the first embodiment are denoted by the same reference numerals and have the same operations and effects.

  The laminated body 402 is different from the laminated body 2 of the first embodiment in that an intermediate member 404 of another form is provided. The configuration, assembly process, operation, and effect not particularly described in the fifth embodiment are the same as those in the first embodiment. Only differences from the first embodiment will be described below.

  The intermediate member 404 is configured by integrally including the main wall portion 40, the fitting piece 442, and the side wall portion 41. The fitting piece 442 is a claw portion that is fitted into the through hole 351 formed in the cooling plate 350 when the intermediate member 404 is assembled to the cooler 5. The fitting piece 442 is a strip-shaped claw portion set in the width direction of the side wall portion 41 (direction in which the electrode terminal 30 protrudes) in the intermediate member 404 with a length of the width W2. The width W2 is set to be equal to or longer than the width W1 of the outer case of the battery cell 3. The through hole 351 formed in the cooling plate 350 is provided at a position corresponding to each fitting piece 442, and has a size that allows the fitting pieces 442 to be fitted to each other.

  Each fitting piece 442 protrudes from the end of the main wall 40 downward (to the cooler 350 side) in parallel with the main wall 40 and larger than the thickness of the side wall 41. Therefore, as illustrated in FIG. 16, each fitting piece 442 has an angle formed with the side wall portion 41 of less than 90 degrees before being fitted into the through hole 351 of the cooling plate 50. Moreover, since each fitting piece 442 is such a shape, it can be formed by cutting down the part of the width W2 including the center part of the side wall part 41 below.

  When fitting the fitting piece 442 into the through hole 351, first, the fitting piece 442 is inserted deeply into the corresponding through hole 351. Then, all of the fitting pieces 442 are fitted into the corresponding through holes 351, and a compressive force is applied to the laminate 402 in a state where all the side wall portions 41 are grounded to the cooling plate 350. Along with the action of the compressive force, the main wall portion 40 is raised from the inclined state and the intermediate member 404 is pushed in the thickness direction X. Due to the fitting of the fitting piece 442 and the through hole 351, the side wall portion 41 contacts the cooling plate 350 while the intermediate member 404 is temporarily fixed to the cooling plate 350, and the main wall portion 40 is connected to the battery cell 3 from both sides. It will be pinched by.

  Further, when the main wall portion 40 is pushed in the thickness direction X, the side wall portion 41 exhibits a reaction force close to a certain kind of spring force, and the side wall portion with the connection portion between the side wall portion 41 and the main wall portion 40 as a fulcrum. The acting force with which 41 is pressed against the cooling plate 350 is increased. As the external force in the thickness direction X acting on the main wall portion 40 increases, the side wall portion 41 is more strongly pressed against the cooling plate 350.

  That is, according to this unique configuration, the structure of the battery pack that can acquire both the adhesion between the side wall 41 and the cooling plate 350 and the adhesion between the main wall 40 and the exterior main wall 31 of the battery cell 3. And sufficient battery cooling performance can be ensured.

  Further, as the first other form of the intermediate member 404, an intermediate member 504 shown in FIG. 17 may be used. The intermediate member 504 is configured by integrally including the main wall portion 40, the fitting piece 542, and the side wall portion 41. Each fitting piece 542 has a form in which the fitting piece 442 of the intermediate member 404 is divided into a plurality of pieces in the width direction of the side wall portion 41 (the direction in which the electrode terminal 30 protrudes). Three fitting pieces 542 are provided at predetermined intervals in the width direction of the side wall 41 in the intermediate member 404. A recess 5420 is formed between the fitting pieces 542 arranged in the width direction of the side wall 41. The through hole 451 formed in the cooling plate 450 is provided at a position corresponding to each fitting piece 542, and has a size that allows the fitting pieces 542 to be fitted to each other.

  When fitting the fitting piece 542 into the through hole 451, first, the fitting piece 542 is inserted deeply into the corresponding through hole 451 until the recess 5420 contacts the cooling plate 450. Then, all the fitting pieces 542 are fitted in the corresponding through holes 451 and all the side wall portions 41 are grounded to the cooling plate 450, and a compressive force is applied to the laminate 502. Along with the action of the compressive force, the main wall portion 40 is raised from the inclined state, and the intermediate member 504 is pushed in the thickness direction X. Due to the fitting of the fitting piece 542 and the through hole 451, the side wall portion 41 comes into contact with the cooling plate 450 while the intermediate member 504 is temporarily fixed to the cooling plate 450, and the main wall portion 40 is connected to the battery cell 3 from both sides. It will be pinched by.

  Further, when the main wall portion 40 is pushed in the thickness direction X, the side wall portion 41 exhibits a reaction force close to a certain kind of spring force, and the side wall portion with the connection portion between the side wall portion 41 and the main wall portion 40 as a fulcrum. The acting force with which 41 is pressed against the cooling plate 450 is increased. As the external force acting on the main wall 40 in the thickness direction X increases, the side wall 41 is more strongly pressed against the cooling plate 450.

  Further, after the intermediate member 404 is fixed to the cooling plate 350 and a compressive force is applied and the plurality of battery cells 3 are restrained, a step of joining the fitting pieces 442 and 542 to the cooling plate 350 by welding is performed. May be. According to this process and configuration, the contact area between the intermediate member 404 and the cooling plate 350 is improved, and the strength and vibration resistance of the battery pack are further improved. Therefore, this configuration and process contribute to an improvement in heat transfer from the battery cell 3 to the cooler 5.

(Sixth embodiment)
In the sixth embodiment, a battery pack including a laminate 602 that is another form of the first embodiment will be described with reference to FIGS. 18 and 19. In each figure, the same components as those in the first embodiment are denoted by the same reference numerals and have the same operations and effects.

  The laminated body 602 is different from the laminated body 2 of the first embodiment in that it includes an intermediate member 604 of another form and is fixed to a cooler 505 of another form. The configuration, assembly process, operation, and effect not particularly described in the sixth embodiment are the same as those in the first embodiment. Only differences from the first embodiment will be described below.

  The battery pack of the sixth embodiment has thermal conductivity and a plurality of battery cells 3 arranged in a stacked manner, a cooler 505 in which heat transfer is performed between the heat medium and the heat medium. And an intermediate member 604 interposed between the battery cells 3 arranged in a stacked manner.

  The intermediate member 604 is a plate-like member having a main wall portion 640 that contacts the exterior main wall 31 of the battery cell 3 and is sandwiched between the adjacent battery cells 3 from both sides. The cooling plate 550 includes a fitting recess 5500 in which the one end portion 6460 of the main wall portion is fitted, and a deforming portion 5501 provided between the fitting recesses 5500 arranged in the thickness direction X. The cooler 505 shown in FIGS. 18 and 19 is configured by a plate-like cooling plate 550 that does not form an internal space.

  The fitting recess 5500 grips the one end portion 6460 of the main wall portion by being deformed in the thickness direction X or the direction crossing the thickness direction X. That is, the deforming portion 5501 constitutes a variable mechanism that is easily deformed by the application of a compressive force and plastically deforms so that the deformed state is not restored to the original shape even if the compressive force is removed. For example, the deformable portion 5501 can be configured as a portion that is thinner than other portions of the cooling plate 550. Further, the deformable portion 5501 is formed by a portion bent in advance in a state before the compressive force is applied, and can be a portion that is easily deformed.

  The battery pack manufacturing method of the sixth embodiment is a method including an assembling step of assembling a plurality of battery cells 3, a cooler 505, and an intermediate member 604. In the assembling step, the end of the intermediate member 604 (one end 6460 of the main wall) is inserted and installed in each fitting recess 5500 (see FIG. 18) in the thickness direction with respect to the cooling plate 550 of the cooler 505. A compressive force is applied to X. By the action of the compressive force, the deformable portion 5501 is deformed, and the length of the cooling plate 550 in the thickness direction X is shortened. Along with this, each fitting recess 5500 is also deformed, the one end portion 6460 of the main wall is gripped by each fitting recess 5500, and the intermediate member 604 is fixed to the cooling plate 550. Here, before applying the compressive force to the cooling plate 550, the one end portion 6460 of the main wall portion may be joined to the fitting recess 5500 by welding, brazing, ultrasonic joining or the like.

  Next, as illustrated in FIG. 19, the spacer 8 is installed between the intermediate members 604, and the outer main wall 31 of the battery cell 3 is placed on the spacer 8 so as to face the main wall portion of the intermediate member 604. Each battery cell 3 is inserted and installed. Thereby, the laminated body 602 in which the intermediate member 604, the spacer 8, and the battery cell 3 are laminated in the thickness direction X is formed. Next, as in the first embodiment, the laminate 602 is configured as a strong integrated product by applying the compressive force of the four restraining members 7 to the laminate 602, and the above-described restraint is completed. To do.

  Further, as shown in FIG. 20, a cooler 605 that forms an internal space may be used. In the cooler 605, a deformed portion 5501 and a fitting recess 5500 are formed on the cooling plate 650 on the side where the one end portion 6460 of the main wall portion is installed, and a back-side deformed portion 652 is also formed on the back-side surface. The back side deformable portion 652 also has a variable mechanism that undergoes plastic deformation that is easily deformed by the application of a compressive force and that does not restore the deformed state to the original shape even when the compressive force is removed. The back side deformation | transformation part 652 can be comprised as a thin part thinner than the other part in the cooler 605, for example. Moreover, the back side deformation | transformation part 652 can also be made into the part which is formed by the part bent previously in the state before compressive force acts, and is easy to deform | transform.

  Further, as shown in FIG. 21, a lid 553 may be joined to the back side of the cooling plate 550. In this way, the cooling plate 550 is formed in the cooler 705 that forms the internal space by welding, brazing, ultrasonic bonding or the like to the cooling plate 550 in the state shown in FIG. 19 on the back side. can do.

  According to the sixth embodiment described above, the coolers 505, 605, and 705 are provided between the fitting recess 5500 in which the one end portion 6460 of the main wall portion is fitted and the fitting recess 5500, and the thickness direction X or the thickness direction. And a deformable portion 5501 deformed in a direction crossing X. The fitting recess 5500 grips the one end portion 6460 of the main wall portion as the deformation portion 5501 is deformed.

  According to this configuration, by the deformation of the deformable portion 5501, the fitting recess 5500 grips and fixes the one end portion 6460 of the main wall portion of the intermediate member 604, and the main wall portion of the intermediate member 604 is connected to the battery cell from both sides. 3 has a unique configuration. According to this configuration, the heat transferability between the intermediate member 604 and the cooling plate 550 can be ensured by the gripping structure of the one end portion 6460 of the main wall portion by the fitting recess 5500. That is, according to this unique configuration, the structure of the battery pack 1 that can obtain both the adhesion between the intermediate member 604 and the cooling plate 50 and the adhesion between the intermediate member 604 and the exterior main wall 31 of the battery cell 3. And sufficient battery cooling performance can be ensured.

  Further, the one end portion 6460 of the main wall portion is gripped by the fitting recess 5500 in a state of being joined to the fitting recess 5500 by welding, brazing, ultrasonic bonding, or the like. According to this step of deforming the deformable portion 5501 after joining, the contact area between the intermediate member 604 and the cooling plates 550 and 650 is improved, and the strength and vibration resistance of the battery pack are further improved. Therefore, this configuration and process contribute to an improvement in heat transfer from the battery cell 3 to the cooler 5.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  The structure of the said embodiment is an illustration to the last, Comprising: The scope of the present invention is not limited to the range of these description. The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

  The battery cell which comprises a battery laminated body in the said embodiment can also be comprised with the single battery which has the square-shaped exterior case which consists of metals. This rectangular unit cell is a flat rectangular parallelepiped whose outer peripheral surface is covered with an outer case made of, for example, aluminum or an aluminum alloy. The battery stack is integrally formed by sandwiching an assembly in which a predetermined number of cells and insulating spacers are alternately stacked, sandwiched between both ends in the stacking direction by a restraining member, and acting a restraining force toward the inside.

  In the above embodiment, an insulating coating may be provided between the main wall portion 40 of the intermediate member 4 and the exterior main wall 31 of the battery cell 3. Further, an insulating coating may be provided between the side wall 41 of the intermediate member 4 and the cooling plate 50. This insulating film can be formed by applying silicon-based heat radiation grease having good thermal conductivity. The insulating coating can be formed by vapor deposition, coating, integral molding, or the like.

  According to such an insulating film, since the intermediate member 4 having good thermal conductivity and the battery cell 3 or the cooling plate 50 come into contact with each other through the insulating material coating portion, electrical insulation is ensured. Therefore, electrical safety can be ensured and metal corrosion can be prevented. The insulating coating may be replaced with an aluminum nitride film or a silicon rubber sheet, or an insulating heat dissipation film may be employed.

  In the above embodiment, the battery stack is an assembly of batteries in which a predetermined number of battery cells and one intermediate member are alternately stacked, but the battery stack is not limited to this form. For example, the intermediate member may be alternately arranged with a plurality of stacked battery cells to constitute a battery stack.

  In the above embodiment, the fluid drive device that forcibly sends the cooling fluid to the fluid passage may be a system that sucks the cooling fluid into the fluid path, or may be a system that pushes the cooling fluid into the fluid path.

DESCRIPTION OF SYMBOLS 1 ... Battery pack 2,102,202,302,402,502 ... Laminated body 3 ... Battery cell 4,104,204,304,404,504,604 ... Intermediate member 5,505; 605; 705 ... Cooler,
31 ... Exterior main wall, 40,640 ... Main wall part, 41 ... Side wall part 42,142,242,342,442,542 ... Fitting piece, 50 ... Cooling plate 51,151,251,351,451 ... Through hole 5500 ... Fitting recess, 5501 ... Deformation part, 6460 ... One end part of main wall part X ... Thickness direction

Claims (15)

A plurality of battery cells (3) arranged in a stack;
A cooler (5) configured to include a main body portion that performs heat transfer with the heat medium by contact with the heat medium, and a cooling plate (50) provided to conduct heat with the main body portion. )When,
An intermediate member (4; 104; 204; 304; 404; 504) having thermal conductivity and interposed between the battery cells arranged in a stack;
With
The intermediate member is
A main wall portion (40) that contacts the exterior main wall (31) of the battery cell that forms a surface orthogonal to the thickness direction (X) of the battery cell and is sandwiched between the adjacent battery cells from both sides;
A fitting piece (42; 142; 242; 342; 442; 542) that fits into a through hole (51; 151; 251; 351; 451) formed in the cooling plate;
A battery pack having a shape extending from the end portion of the main wall portion along the thickness direction and having a side wall portion (41) in contact with the cooling plate.   The end of the fitting piece extending so as to penetrate the through hole is in contact with the cooling plate at a back surface with respect to the surface of the cooling plate with which the side wall contacts. The battery pack according to 1.   3. The battery pack according to claim 2, wherein the front end portion of the fitting piece extends in the same direction as a direction in which the side wall portion extends from an end portion of the main wall portion and contacts the cooling plate.   3. The battery pack according to claim 2, wherein the front end portion of the fitting piece extends in a direction opposite to a direction in which the side wall portion extends from the end portion of the main wall portion and contacts the cooling plate.   5. The device according to claim 1, further comprising: a pair of end plates (6) that apply a compressive force to the plurality of battery cells and the intermediate member from both sides in the thickness direction. 6. The battery pack according to item. A plurality of battery cells (3) arranged in a stack;
A cooler (505; 605; 705) in which heat transfer is performed between the heating medium and the heating medium,
An intermediate member (604) having thermal conductivity and interposed between the battery cells arranged in a stack;
With
The intermediate member is in contact with the outer main wall (31) of the battery cell forming a surface orthogonal to the thickness direction (X) of the battery cell, and the main wall portion (640) sandwiched by the adjacent battery cell from both sides. )
The cooler is provided between a fitting recess (5500) into which one end portion (6460) of the main wall portion is fitted and the fitting recess arranged in the thickness direction, and intersects the thickness direction or the thickness direction. A deformed portion (5501) deformed in the direction,
The fitting recess grips one end portion of the main wall portion with the deformation of the deformation portion.   The battery pack according to claim 6, wherein one end of the main wall is gripped by the fitting recess while being joined to the fitting recess.   The spacer according to claim 6 or 7, wherein a spacer (8) is interposed between the intermediate members arranged in the thickness direction and further between the battery cell and the cooler. Battery pack.   The said battery cell and the said intermediate member are laminated | stacked on the said thickness direction in the state in which at least one surface of the exterior main wall of the said battery cell contact | connects the main wall part of the said intermediate member, The 1 thru | or Claim characterized by the above-mentioned. The battery pack according to any one of 8.   The battery pack according to any one of claims 1 to 9, wherein the positive electrode of the battery cell includes a polyanion-based substance. The polyanionic substance is a compound having a chemical formula represented by LiMPO ₄ or Li ₂ MSiO ₄ , wherein M is at least one metal element selected from Mn, Fe, Co, and Ni. The battery pack according to claim 10. A plurality of battery cells (3) arranged in a stack;
Cooling having a main body part in which heat transfer is performed with the heat medium by contact with the heat medium, and cooling plates (50, 150, 250, 350; 450) provided to conduct heat with the main body part. Vessel (5),
A main wall portion (40) that is an intermediate member that has thermal conductivity and is interposed between battery cells that are arranged in a stack, and that is perpendicular to the thickness direction (X) of the battery cells, and an end of the main wall portion A side wall part (41) extending from the part and having an angle of more than 90 degrees with the main wall part in advance, and a fitting piece (42; 142; 242; extending from an end part of the main wall part) 342; 442; 542) and an intermediate member (4; 104; 204; 304; 404; 504);
A battery pack manufacturing method including an assembly step of assembling
The assembly process includes
The main wall portion of the intermediate member is opposed to the outer main wall (31) of the battery cell that forms a surface orthogonal to the thickness direction, the side wall portion of the intermediate member and the cooling plate are brought into contact with each other, and In the state where the fitting pieces are fitted into the through holes (51; 151; 251; 351; 451) formed in the cooling plate, and the battery cells and the intermediate member are laminated in the thickness direction,
A compressive force is applied in the thickness direction to the laminate (2; 102; 202; 302; 402; 502) including the plurality of battery cells and the intermediate member, so that the main wall portion and the side wall portion are The intermediate member is deformed so that the angle exceeding 90 degrees is reduced, and the battery plate and the intermediate member are brought into close contact with each other, and the cooling plate and the side wall of the intermediate member are brought into close contact with each other. Battery pack manufacturing method.   The battery pack according to claim 12, wherein the fitting piece (42; 142) has a shape bent with respect to the main wall portion from a state before being fitted into the through hole (51). Manufacturing method.   In the assembling step, the fitting piece is further configured such that the end (3420) of the fitting piece is brought into contact with the cooling plate on the back surface with respect to the surface of the cooling plate with which the side wall portion contacts. The method of manufacturing a battery pack according to claim 12 or 13, wherein the battery pack is bent.   In the assembly step, a pair of end plates provided with rod-shaped restraining members (7) having a bolt part (70) at one end and a male screw part (71) at the other end on both sides of the laminate. (6) and the intermediate member are inserted so as to penetrate through, and the end plate is moved in the thickness direction by tightening a nut (72) screwed into the male screw portion, thereby moving the end plate in the thickness direction. The method for manufacturing a battery pack according to any one of claims 12 to 14, wherein the compressive force is applied to the laminated body so that the battery cell and the intermediate member are brought into close contact with each other.

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