JP6657748B2 - Battery module and method of manufacturing battery module - Google Patents

Description

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

  2. Description of the Related Art There is known a battery pack in which a battery module in which a plurality of battery cells held in a battery holder are arranged is attached to a housing or the like. Patent Literature 1 discloses a battery module and a battery pack in which a heat transfer plate is attached to a battery holder and the heat transfer plate is brought into contact with a housing via a heat conductive member to improve heat dissipation. I have. In the battery module and the battery pack, a pressure plate, which is an elastic member, is arranged at an end in the arrangement direction of the plurality of arranged battery cells. Thereby, expansion and contraction in the arrangement direction of the battery cells are absorbed in a certain range.

JP 2015-156303 A

  However, in the above-described conventional battery module and battery pack, the amount of movement of the battery cell (the battery cell closer to the pressure plate) farther from the end plate increases with respect to the housing as the fixed member. Therefore, the heat transfer plate fixed to the battery cell or the battery holder having a large amount of movement may damage the heat conductive member in contact with the heat transfer plate and reduce the heat radiation efficiency.

  Therefore, an object of the present invention is to provide a battery module and a method of manufacturing the battery module that can suppress a decrease in heat radiation efficiency.

  The battery module of the present invention has a plurality of battery cells arranged in one direction, a pair of end plates sandwiching the plurality of battery cells, and a plate-shaped battery contacting a surface intersecting the battery cell in one direction. A heat transfer plate, a solid and elastic heat conductive member that is disposed in contact with a main surface intersecting in one direction in the heat transfer plate and is formed by curing a liquid heat conductive material, and a pair of end plates And a connecting member for connecting each other.

  According to the battery module having this configuration, the solid and elastic heat conductive member formed by curing the liquid heat conductive material is disposed between the battery cells adjacent to each other in one direction. Therefore, the plurality of heat conducting members arranged in contact with the plate-shaped heat transfer plate arranged between the adjacent battery cells disperse and absorb the expansion of the battery cells. In other words, even if the battery cell expands, the amount of expansion can be absorbed by the elastic heat conductive member arranged adjacently, so that the movement amount of each battery cell is suppressed. As a result, damage to the heat conducting member due to movement of the battery cell, that is, movement of the heat transfer plate can be suppressed, and a decrease in heat radiation efficiency can be suppressed.

  In the battery module of the present invention, the heat conductive member has a frame-shaped first heat conductive portion forming the outer shape of the heat conductive member and a second heat conductive portion inside the frame in the first heat conductive portion. The heat conducting portion may be made of a sheet-like heat conducting material, and the second heat conducting portion may be formed by curing a liquid heat conducting material and have a solid and elasticity.

  In the battery module having this configuration, the frame-shaped first heat conductive portion is arranged on the main surface of the heat transfer plate that intersects in one direction, and the liquid heat conductive material is poured into the frame of the first heat conductive portion and solidified. By doing so, the second heat conducting portion is formed. Thereby, the heat conductive member can be formed using the liquid heat conductive material. That is, when a sheet-like heat conductive material is attached to the heat transfer plate, a phenomenon that air bubbles easily enter is avoided, so that a reduction in heat transfer efficiency can be suppressed.

  In the battery module of the present invention, the thermal conductivity of the first thermal conductive section may be higher than the thermal conductivity of the second thermal conductive section.

  In the battery module having this configuration, since heat is easily conducted from the inside to the outside of the heat conducting member, the heat generated in the battery cells can be efficiently radiated to the outside.

  In the battery module according to the present invention, the thickness of the second heat conductive portion may be larger than the thickness of the first heat conductive portion.

  In the battery module having this configuration, since the second heat conductive portion is pressed against the heat transfer plate and the battery cell, the heat generated in the battery cell can be more reliably transferred to the heat transfer plate.

  In the method for manufacturing a battery module according to the present invention, a plurality of battery cells arranged in one direction, a pair of end plates sandwiching the plurality of battery cells, and a battery cell are disposed in contact with a surface intersecting in one direction. A method for manufacturing a battery module, comprising: a plate-shaped heat transfer plate; a heat conductive member arranged in contact with a main surface intersecting in one direction in the heat transfer plate; and a connecting member connecting the pair of end plates. In the step of arranging a plate-shaped heat transfer plate between battery cells adjacent to each other in one direction, and arranging a frame-shaped first heat conduction portion on a main surface of the heat transfer plate crossing in one direction. Forming a second heat conductive portion by pouring and solidifying a liquid heat conductive material inside the frame of the first heat conductive portion.

  According to this manufacturing method, a solid and elastic heat conductive member formed by curing a liquid heat conductive material is disposed between battery cells adjacent to each other in one direction. Therefore, the plurality of heat conducting members arranged in contact with the plate-shaped heat transfer plate arranged between the adjacent battery cells disperse and absorb the expansion of the battery cells. In other words, even if the battery cell expands, the amount of expansion can be absorbed by the elastic heat conductive member arranged adjacently, so that the movement amount of each battery cell is suppressed. As a result, damage to the heat conducting member due to movement of the battery cell, that is, movement of the heat transfer plate can be suppressed, and a decrease in heat radiation efficiency can be suppressed. Further, according to this manufacturing method, the heat conductive member can be formed using a liquid heat conductive material. That is, when a sheet-like heat conductive material is attached to the heat transfer plate, a phenomenon that air bubbles easily enter is avoided, so that a reduction in heat transfer efficiency can be further suppressed.

  In the method for manufacturing a battery module according to the present invention, the thermal conductivity of the first thermal conductive portion may be higher than the thermal conductivity of the second thermal conductive portion.

  According to this manufacturing method, since heat is easily conducted from the inside to the outside of the heat conducting member, the heat generated in the battery cells can be efficiently radiated to the outside.

  In the method for manufacturing a battery module according to the present invention, the second heat conductive portion may be formed to be thicker than the first heat conductive portion.

  According to this manufacturing method, since the second heat conducting portion is pressed against the heat transfer plate and the battery cell, the heat generated in the battery cell can be more reliably transferred to the heat transfer plate.

  According to the present invention, a decrease in heat radiation efficiency can be suppressed.

It is a perspective view showing the battery pack in one embodiment. It is a perspective view showing a battery module in one embodiment. FIG. 2 is an exploded perspective view showing a battery holder, a battery cell, a heat transfer plate, and a heat conducting member according to one embodiment. It is sectional drawing of the battery module in one Embodiment. (A) And (B) is a top view of the heat conduction member arrange | positioned in contact with a heat transfer plate. It is sectional drawing of the heat conductive member arrange | positioned in contact with a heat transfer plate. 3 is a flowchart illustrating an example of a method for manufacturing the battery module of FIG. 2.

  Hereinafter, a battery pack 10 according to an embodiment will be described with reference to the drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. The dimensional ratios in the drawings do not always match those described.

  As shown in FIG. 1, the battery pack 10 has a housing 11. A plurality of battery modules 21 are housed in the housing 11. The housing 11 has a rectangular box shape, a rectangular flat bottom plate 12, a rectangular flat side wall 13 erected from the periphery of the bottom plate 12, and a rectangular flat plate closing an opening surrounded by the side wall 13. And a top plate 14.

  As shown in FIG. 2, the battery module 21 includes a plurality of battery cells 23, a pair of brackets (end plates) 25, 25, a heat transfer plate 41, a heat conductive member 45, and bolts B serving as connecting members. And a nut N.

  The battery cell 23 is, for example, a secondary battery such as a lithium ion secondary battery and a nickel hydride storage battery. The battery cells 23 are juxtaposed in one direction D while being held by the battery holder 22.

  As shown in FIG. 3, the battery holder 22 includes a first covering part 31, a second covering part 32, a third covering part 33, a fourth covering part 34, a pair of legs 36, 36, have.

  The first covering portion 31 is a portion formed in a rectangular flat plate shape and covering the bottom of the battery cell 23. The second covering portion 32 and the third covering portion 33 are portions that stand from both ends in the longitudinal direction of the first covering portion 31. The second covering portion 32 and the third covering portion 33 are formed in a rectangular flat plate shape, and cover side surfaces of the battery cell 23. The fourth covering portion 34 is a portion formed in a rectangular flat plate shape and covering a part of one main surface (a surface orthogonal to the thickness direction) of the battery cell 23. The fourth covering portion 34 includes a first end portion 32 a in the longitudinal direction of the second covering portion 32 (an end portion opposite to the end portion on which the first covering portion 31 is provided) and a longitudinal direction of the third covering portion 33. Is connected to the first end 33a (the end opposite to the end on which the first covering portion 31 is provided). The fourth covering portion 34 is arranged such that its thickness direction matches the direction in which the battery cells 23 are arranged, and its longitudinal direction matches the direction in which the second covering portion 32 and the third covering portion 33 face each other. A region surrounded by the first covering portion 31, the second covering portion 32, and the third covering portion 33 becomes a housing portion S in which the battery cell 23 is housed.

  At the first end portions 32a, 33a in the longitudinal direction of the second covering portion 32 and the third covering portion 33, a rectangular flat plate extending in the longitudinal direction of the covering portions 32, 33 is provided so as to be continuous with the covering portions 32, 33. Is provided. Further, quadrangular pillar-shaped legs 36 are provided at the second end portions 32c and 33c in the longitudinal direction of the second covering portion 32 and the third covering portion 33.

  As shown in FIGS. 3 and 4, the pair of brackets 25, 25 are provided at both ends in the juxtaposition direction of the battery cells 23 juxtaposed in one direction D. The bracket 25 has a holding portion 25a, a fixing portion 25b, and an insertion hole 25c formed in the fixing portion 25b. The battery module 21 is fixed to the housing 11 by fixing the fixing portion 25 b of the bracket 25 to the side wall 13. Specifically, the bracket 25 is fixed to the housing 11 by screwing the bolt 25d inserted into the insertion hole 25c into the side wall 13.

  Bolts B and nuts N, which are connecting members, connect the pair of brackets 25, 25 to each other. Bolts B are inserted into both brackets 25. The bolt B is inserted from one bracket 25 toward the other bracket 25 and is screwed to the nut N at a position where the other bracket 25 is inserted.

  The heat transfer plate 41 is a plate-shaped member arranged between the battery cells 23 adjacent to each other in one direction D. The heat transfer plate 41 is formed by bending a metal plate material into an L-shape, and has a rectangular flat plate-shaped main body portion 42 and a rectangular flat plate-shaped bent portion bent at a right angle from one longitudinal end of the main body portion 42. And a portion 43. The main body 42 is provided in the housing portion S in a state of being adjacent to the battery cell 23 in the thickness direction of the battery cell 23. The bent portion 43 covers the outer surface of the third covering portion 33 (the surface on the side opposite to the accommodation portion S in the thickness direction of the third covering portion 33).

  The heat conducting member 45 is disposed in contact with the main surface 42 a of the heat transfer plate 41 that is orthogonal (intersecting) in one direction D. The heat conductive member 45 has a solid and elastic second heat conductive part 47 formed by curing a liquid heat conductive material (TIM: Thermal Interface Material). Specifically, as shown in FIGS. 5A and 5B, the heat conducting member 45 includes a frame-shaped first heat conducting portion 46 forming the outer shape of the heat conducting member and a first heat conducting portion 46. And a second heat conducting portion 47 inside the frame in the portion 46.

  As shown in FIG. 5A, an example of the first heat conductive portion 46 is a sheet-like heat conductive material (TIM), for example, a silicon-based / acryl-based resin. The first heat conducting portion 46 has a frame-shaped main body 46a and a frame inside 46b inside the main body 46a. An example of the second heat conducting portion 47 (liquid heat conducting material) is polyurethane. The solid state may be a state having a certain volume and shape, and may be a gel state. Further, the second heat conducting portion 47 may have adhesiveness. As shown in FIG. 5 (B), the second heat conducting portion 47 is formed inside the frame 46b inside the main body 46a.

The thermal conductivity of the first heat conducting portion 46 (for example, 1.5 [W / m · K] to 3.0 [W / m · K]) is the thermal conductivity of the second heat conducting portion 47 (for example, 1.6 [W / m · K] or more.
Further, the thickness T2 (for example, 0.5 mm to 3.0 mm) of the second heat conduction portion 47 is larger than the thickness T1 (for example, 0.6 mm or more) of the first heat conduction portion 46. The thicknesses T1 and T2 of the first heat conduction portion 46 and the second heat conduction portion 47 are appropriately adjusted according to the required restraint load and / or the type of the heat conduction material used.

  As shown in FIG. 4, the battery module 21 is fixed such that the bent portion 43 faces the side wall 13 as the fixed member. A heat conducting member 51 (TIM: Thermal Interface Material) is arranged between the battery module 21 (bent portion 43) and the side wall 13.

  The heat conducting member 51 is a member made of a sheet-like material having both surfaces having adhesiveness. Further, the heat conductive member 51 has an insulating property. As such a heat conductive member having insulating properties, a heat conductive sheet containing no metal filler can be used. In addition, the heat conductive member 51 includes a silicone-based heat conductive sheet and an acrylic-based heat conductive sheet. When a silicone-based heat conductive sheet is used, the range of operating temperature can be widened because of its excellent cold resistance and heat resistance. In addition, a silicone-based heat conductive sheet that does not use a metal filler is suitable for an insulating material because the change in electrical characteristics due to temperature and frequency is small. On the other hand, the acrylic sheet does not generate siloxane gas, and thus does not cause contact failure and wear of mechanical contacts in a closed space. Acrylic sheets are generally less expensive than silicone.

  Next, an example of a method for manufacturing the battery module 21 of the present embodiment will be described mainly with reference to FIGS. In the method for manufacturing the battery module 21, first, the heat transfer plate 41 is prepared (Step S1). Next, a frame-shaped first heat conducting portion 46 (see FIG. 5A) is arranged on the main surface 42a of the heat transfer plate 41 orthogonal to the one direction D (step S2). The first heat conductive portion 46 is a sheet-like material having at least one surface having adhesiveness, and is attached to the heat transfer plate 41 by peeling off a film or the like covering the adhesive surface.

  Next, a liquid heat conductive material is poured (applied) into the frame inside 46b (see FIG. 5B) of the first heat conductive portion 46 and solidified to form the second heat conductive portion 47 (see FIG. 5B). Step S3). In step S <b> 3, a member having a higher thermal conductivity than the second thermal conductive portion 47 is used as the first thermal conductive portion 46. Further, the thickness T2 of the second heat conduction portion 47 is formed to be larger than the thickness T1 of the first heat conduction portion 46 (see FIG. 6).

  Next, as shown in FIG. 3, the battery cells 23 are housed in the battery holder 22 (Step S4). Next, in step S2 and step S3, the heat transfer member 45 including the first heat transfer section 46 and the second heat transfer section 47 is arranged so that the battery cells 23 accommodated in the battery holder 22 come into contact with each other. The plates 41 are overlaid (step S5). Next, the battery cells 23, the battery holder 22, and the heat transfer plate 41 are arranged along one direction D (step S6). Thus, an array including the battery cells 23, the battery holder 22, and the heat transfer plate 41 is formed.

  The array is sandwiched between a pair of brackets 25, 25 (step S7). Then, the pair of brackets 25, 25 are connected by a connecting member (step S8). Specifically, a bolt B is inserted from one bracket 25 toward the other bracket 25, and is screwed with a nut N at a position where the other bracket 25 is inserted. Thereby, the battery module 21 as shown in FIG. 2 is manufactured.

  Next, the operation and effect of the battery module 21 of the present embodiment will be described. According to the battery module 21 of the above embodiment, the solid and elastic second heat conducting portion 47 formed by curing the liquid heat conducting material is disposed between the battery cells 23 adjacent to each other in one direction D. ing. Therefore, the plurality of second heat conducting portions 47 arranged in contact with the plate-shaped heat transfer plate 41 arranged between the adjacent battery cells 23 disperse and absorb the expansion of the battery cells 23. In other words, even if the battery cell 23 expands, the amount of expansion can be absorbed by the elastic second heat conducting portion 47 disposed adjacent to the battery cell 23, so that the movement amount of each battery cell 23 is suppressed. As a result, damage to the heat conducting member 51 due to movement of the battery cell 23, that is, movement of the heat transfer plate 41, can be suppressed, and a decrease in heat radiation efficiency can be suppressed.

  In the above embodiment, since the thermal conductivity of the first thermal conductive portion 46 is higher than the thermal conductivity of the second thermal conductive portion 47, heat is easily conducted from the inside to the outside of the thermal conductive member 45. Thereby, the heat generated in the battery cells 23 can be efficiently radiated to the outside.

  In the above embodiment, since the thickness T2 of the second heat conduction part 47 is larger than the thickness T1 of the first heat conduction part 46, the second heat conduction part 47 is pressed against the heat transfer plate 41 and the battery cells 23. Thereby, the heat generated in the battery cells 23 can be more reliably transferred to the heat transfer plate 41.

  Further, according to the method for manufacturing the battery module 21, the second heat conducting portion 47 can be formed using a liquid heat conducting material. That is, when a sheet-like heat conductive material is attached to the heat transfer plate, a phenomenon that air bubbles easily enter is avoided, so that a reduction in heat transfer efficiency can be further suppressed.

  As described above, one embodiment has been described, but the present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit of the invention.

  In the above-described embodiment, the example in which the heat conductive members 45 are arranged in contact with the main surfaces of all the heat transfer plates 41 has been described. However, for example, heat transfer in which the heat conductive members 45 are arranged in one direction D is described. The plate 41 and the heat transfer plate 41 on which the heat conduction member 45 is not arranged may be alternately arranged, or the heat conduction member 45 may not be arranged on any heat transfer plate 41. However, it is preferable that the heat transfer plates 41 be disposed in contact with all the heat transfer plates 41 since the movement amounts of the respective heat transfer plates 41 during expansion can be made small and uniform.

  In the above embodiment, as shown in FIG. 3, an example in which the heat conducting member 45 is disposed on one main surface 42 a of the heat transfer plate 41 has been described. The heat conducting member 45 may be arranged, or may be arranged on both the one main surface 42a and the other main surface 42b of the heat transfer plate 41. Further, in the above embodiment, a heat conducting member 45 as shown in FIG. 5B may be arranged between the bracket 25 at the left end in FIG. 4 and the battery cell 23.

  In the above embodiment, an example in which the heat conducting member 45 is formed from the first heat conducting portion 46 made of a sheet-like heat conducting material and the second heat conducting portion 47 made by solidifying a liquid heat conducting material is given. As described above, it may be formed only from the second heat conductive portion 47 formed by solidifying a liquid heat conductive material. In this case, a frame-shaped jig or the like is installed on one main surface 42a of the heat transfer plate 41, and a liquid heat conductive material is poured (applied) into the jig, thereby forming one main surface of the heat transfer plate 41. The heat conducting member 45 can be arranged at 42a.

  In the above embodiment or the modified example, the example in which the heat conductive member 51 is configured by arranging the sheet-like material (TIM) is described, but the present invention is not limited thereto. For example, after applying the liquid TIM, the battery module 21 may be fastened to the side wall 13. In this case, the heat conductive member 51 is formed by curing the liquid TIM.

  At this time, the intersection angle between the main body portion 42 and the bent portion 43 in the heat transfer plate 41 may be larger than 90 degrees. According to this configuration, a liquid heat conductive material is applied to the inner wall surface (side wall 13) of the housing 11, and the bent portion 43 of the heat transfer plate 41 is applied to the heat conductive material so as to face the inner wall surface of the housing 11. At the time of contact, even if air bubbles are generated between the heat transfer plate 41 and the heat conductive material, the generated air bubbles move along the inclined surface. Thereby, even if the heat conductive material is cured and the heat conductive member 51 is formed, the possibility that a gap caused by air bubbles is generated between the bent portion 43 of the heat transfer plate 41 and the heat conductive member 51 is reduced. be able to. That is, the heat dissipation of the battery cells 23 can be improved.

  Further, a groove extending from the edge of the bent portion 43 may be provided in the bent portion 43, and the depth of the groove may be formed to increase as approaching the edge of the bent portion 43. Thereby, the generated bubbles can be moved along the groove to the edge of the bent portion 43 and can be removed from between the bent portion 43 of the heat transfer plate 41 and the heat conducting member 45.

  At this time, the array of the battery cells 23, the battery holder 22, and the heat transfer plate 41 of the battery module 21 restrains each other so that the distance from the side wall 13 to the heat transfer surface increases in one direction D. You may. With this configuration, when the battery module is fixed to the housing 11, the air between the heat conductive member 51 and the heat transfer surface is pushed out in one direction D, and the heat transfer member 51 and the heat transfer member It is possible to suppress bubbles from remaining between the surface and the surface. As a result, the contact area between the heat conducting member 51 and the heat transfer surface increases, and the heat transfer efficiency can be improved.

  In the above embodiment or the modified example, the bracket 25 in which the fixing portion 25b and the holding portion 25a are integrally formed has been described as an example. However, the fixing portion 25b and the holding portion 25a may be formed of different members. Good.

  In the above-described embodiment or the modification, the example in which the heat conductive member 51 is not arranged between the bracket 25 and the side wall 13 has been described. However, the heat conductive member 51 is arranged between the bracket 25 and the side wall 13. It is good also as a structure which performs.

  In the above embodiment or the modification, the battery module 21 in which the battery cells 23 held in the battery holder 22 are arranged is described as an example. However, the battery module 23 is not held in the battery holder 22 and only the battery cell 23 is provided. May be used.

  In the above embodiment or the modification, the side wall 13 of the housing 11 in the battery pack 10 has been described as an example of the fixed member, but a counterweight mounted on an industrial vehicle may be used.

  In the embodiment or the modified example, the example in which the plurality of battery modules 21 have the same configuration has been described, but the present invention is not limited to this. For example, a battery pack having a plurality of battery modules 21 having different types of battery cells 23 may be used.

  The various embodiments and modifications described above may be combined in various ways without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Battery pack, 11 ... Case, 13 ... Side wall, 21 ... Battery module, 22 ... Battery holder, 23 ... Battery cell, 25 ... Bracket (end plate), 41 ... Heat transfer plate, 42 ... Body part, 42a ... Principal surface, 43: bent portion, 45: heat conductive member, 46: first heat conductive portion, 46a: main body portion, 46b: inside frame, 47: second heat conductive portion (heat conductive member), 51: heat conductive member , B: bolt (connection member), D: one direction, N: nut (connection member).

Claims (7)

A battery module housed in the housing and fixed to the housing,
A plurality of battery cells arranged in one direction, a pair of end plates sandwiching the plurality of battery cells, and a plate-shaped heat transfer plate arranged in contact with a surface of the battery cells that intersects in the one direction. A module-side heat conductive member which is disposed in contact with the main surface intersecting in the one direction in the heat transfer plate and has a solid elasticity obtained by hardening a liquid heat conductive material; and the pair of ends. A connecting member for connecting the plates,
The heat transfer plate is configured such that when the battery module is fixed to the housing, the heat transfer plate contacts the housing via a housing-side heat conductive member disposed between the battery module and the housing. Are located ,
The module-side heat conductive member has a frame-shaped first heat conductive portion forming an outer shape of the module-side heat conductive member and a second heat conductive portion inside the frame in the first heat conductive portion,
The battery module , wherein the first heat conductive portion is formed of a sheet-shaped heat conductive material, and the second heat conductive portion is formed by curing a liquid heat conductive material and has a solid state and elasticity . The first heat conductive portion includes a frame-shaped main body portion, and a said frame interior is enclosed by the main body portion, the battery module according to claim 1. The thermal conductivity of the first heat-conducting portion, the second higher than the thermal conductivity of the heat conductive portion, claim 1 or 2 cell module according. The battery module according to any one of claims 1 to 3 , wherein a thickness of the second heat conductive portion is larger than a thickness of the first heat conductive portion. A battery module housed in a housing and fixed to the housing, the battery module being arranged in one direction, a pair of end plates sandwiching the battery cells, and the one of the battery cells. A plate-shaped heat transfer plate arranged in contact with a surface intersecting in a direction, a heat conducting member arranged in contact with the main surface intersecting in one direction in the heat transfer plate, and the pair of end plates A heat transfer plate, wherein the heat transfer plate is arranged between the battery module and the housing when the battery module is fixed to the housing. In the method for manufacturing a battery module, the battery module is arranged to be in contact with the housing via a member.
Arranging a plate-shaped heat transfer plate between the battery cells adjacent to each other in the one direction,
A step of arranging a first heat conduction portion having a frame-shaped main body portion and a frame inside surrounded by the main body portion on a main surface intersecting the one direction in the heat transfer plate,
Forming a second heat conductive portion by pouring and solidifying a liquid heat conductive material into a frame surrounded by the main body portion of the first heat conductive portion, thereby forming a second heat conductive portion. . The method for manufacturing a battery module according to claim 5 , wherein the thermal conductivity of the first thermal conductive portion is higher than the thermal conductivity of the second thermal conductive portion. The method for manufacturing a battery module according to claim 5 , wherein the second heat conductive portion is formed so as to be thicker than the thickness of the first heat conductive portion.