JP2009301877A - Battery pack device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact battery pack device which uniformalizes cooling characteristics of respective unit battery cells, prevents defects such as dust deposition and leakage due to dew condensation, and ensures high cooling efficiency. <P>SOLUTION: This battery pack device includes a battery pack member (101) having a plurality of unit battery cells (1) formed in a rectangular solid shape and a plurality of thermal conduction members (2) formed in a plate shape from flexible material with thermal conductivity and electrical insulation properties, both of which are adhered to each other and alternately installed in rows and then pressed and fastened from both ends in the direction of installation rows; and a cooling passage (102) which is formed in contact with one surface of the battery pack member (101) in a tunnel shape allowing refrigerant circulation. At least one part of the thermal conduction member (2) is exposed to the cooling passage (102) for heat transfer, and a partition wall (103) partitioning the cooling passage (102) from the outside is composed of an insulated wall. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an assembled battery device in which a plurality of unit cells each having a rectangular parallelepiped shape are arranged in a row.

  Nickel / hydrogen secondary batteries, lithium ion secondary batteries, and the like used as drive power sources for electric vehicles are required to have a high energy density and are required to have a small mounting space. Therefore, it is common to use a battery pack in which a plurality of single battery cells are assembled. For example, several tens to several tens of V single battery cells having a rectangular parallelepiped shape are connected in series, and these are put in one package to form an assembled battery. This assembled battery is mounted, for example, in the lower part of the rear seat, the trunk room, or the like.

  By the way, the performance and life of the assembled battery greatly depend on the temperature environment, and the deterioration is remarkable at a high temperature. Therefore, a cooling passage communicating with the atmosphere is formed on the surface of the single battery cell, and air in the passenger compartment is introduced into the cooling passage, or the air from the air conditioner is forcibly introduced.

  On the other hand, in a nickel-hydrogen secondary battery or the like, it is inevitable that the unit cell having a rectangular parallelepiped shape expands during charging and the widest side surface expands outward in an arc shape. If it becomes like this, in the assembled battery which assembled | stacked the single battery cell which makes a rectangular parallelepiped shape, the wall surfaces which oppose may contact in a small contact area, and a big stress may concentrate on a contact part.

  Therefore, for the purpose of uniforming the internal pressure of each single battery cell and making the charge / discharge characteristics of each single battery cell uniform, the single battery cells are arranged in a state in which a predetermined load is applied and restrained under pressure. ing. For example, in the assembled battery device introduced in Japanese Patent Application Laid-Open No. 2001-313018, a plurality of unit cells are arranged in the thickness direction, and one constraining plate is stacked on each end in the thickness direction. The two restraining plates are tightened in the direction approaching each other by the restraining rod. By tightening the two restraining plates in a direction approaching each other, the plurality of single battery cells are brought into close contact with each other, and the expansion can be regulated by applying a load to each single battery cell.

  However, in the above assembled battery device, there is a problem that the single unit cell at the center part is less likely to dissipate heat than the single unit cell at the end. Thus, if there is a difference in the cooling characteristics between the single battery cells, the output and life of each single battery cell will vary, resulting in the output of the assembled battery device becoming unstable and shortening the life. End up.

  Japanese Patent Laid-Open No. 2007-012486 proposes an assembled battery device in which the upper part of a plurality of single battery cells is housed in a sealed battery chamber and the lower part of each single battery cell is exposed to a cooling chamber. According to this assembled battery device, each single battery cell can be uniformly cooled by circulating cooling air or the like in the cooling chamber.

  Japanese Patent Application Laid-Open No. 07-045310 discloses that a heat pipe is disposed in the vicinity of each single battery cell, and an end portion of the heat pipe is engaged with a heat radiating plate to radiate heat of the single battery cell to the outside. An assembled battery device as described above has been proposed.

  However, these assembled battery devices have a complicated structure and thus become large and have problems in terms of space and cost.

Therefore, as shown in FIG. 8, spacers 901 are interposed between the single battery cells 900, and a plurality of rows are alternately arranged so that the widest side surfaces of the adjacent single battery cells 900 face each other via the spacers 901. In other words, a restraint plate 902 is disposed at both ends and restrained in the row direction by a restraint rod or the like (see, for example, JP-A-2006-048996). In this assembled battery device, a space 904 having a height of 1 to 2 mm is formed between the single battery cell 900 and the spacer 901 by forming the rib 903 on the spacer 901. Therefore, even when the unit cell 900 is expanded, it is possible to prevent interference between the opposing wall surfaces. Further, the battery cell 900 can be cooled by circulating a cooling medium such as air in the space 904. Thereby, the cooling characteristic between each single battery cell 900 can be equalize | homogenized, and lifetime can be lengthened.
JP 2001-313018 Japanese Patent Laid-Open No. 07-045310 JP 2007-012486 A JP 2006-048996 A

  However, in the assembled battery device described in Patent Document 4, dust or the like may accumulate in the space 904, which makes uniform cooling difficult and causes a difference in the cooling characteristics of the individual battery cells. In addition, air from an air conditioner is generally used as the cooling medium, but condensation may occur in the space 904 due to a temperature difference from the outside air, and it can be said that there is no possibility of leakage due to water droplets moving to the electrode part. Absent.

  Therefore, the applicant of the present application has proposed an assembled battery device in which a sheet made of a soft material having high thermal conductivity, such as silicone rubber, is sandwiched between single battery cells in Japanese Patent Application No. 2007-219812. According to this battery device, when the pressure is restrained from both ends in the row direction, the soft sheet is compressed by the single battery cells on both sides and is in close contact with the widest surface of the single battery cells. Thereby, the heat of the single battery cell is conducted from the sheet to the heat radiating surface and radiated to the heat radiating space.

  That is, since there is no gap between the single battery cell and the sheet, the problem of dust accumulation in the conventional space 904 does not occur. Therefore, even after long-term use, the cooling conditions for each single battery cell are almost the same, so that the cooling characteristics between the single battery cells can be made uniform, and the life is prolonged.

  Furthermore, it is not necessary to form a space for circulating cooling air as described in Patent Document 3 between the single battery cells. Therefore, the distance between single battery cells can be reduced, and the whole becomes a compact shape, and the mounting space can be reduced. Further, if the heat dissipating surface is formed at a position far from the electrode, it is possible to prevent leakage due to condensation.

  However, the heat of the single battery cell is conducted from the sheet to the heat radiating surface and released to the heat radiating space. However, the heat radiating space is partitioned by a casing that houses the unit cells, and is thermally connected to an external environment (for example, an environment including exhaust heat from an automobile exhaust pipe or the like). For this reason, when the heat from the external environment flows into the heat dissipation space, the temperature in the heat dissipation space rises, and the temperature difference between the heat dissipation surface and the heat dissipation environment tends to be small or unstable. Therefore, the heat dissipation (cooling efficiency) of the single battery cell is likely to decrease.

  The present invention has been made in view of the above circumstances, and in an assembled battery device in which unit cells are arranged in a row, the cooling characteristics of each unit cell are made uniform, and problems such as electric leakage due to dust accumulation and condensation are prevented. An object to be solved is to provide a battery pack device that is compact and has high cooling efficiency.

(1) The assembled battery device of the present invention includes a unit cell (1) having a rectangular parallelepiped shape, and a heat conductive member (2) formed in a plate shape from a soft material having thermal conductivity and electrical insulation. A plurality of battery packs (101), which are alternately arranged in close contact with each other and are pressed and restrained from both ends in the arrangement direction, are formed in contact with one surface of the battery pack member (101). A tunnel-shaped cooling passage (102) through which a refrigerant flows, and at least a part of the heat conducting member (2) is exposed to the inside of the cooling passage (102) so that heat can be transferred to the cooling passage (102). The partition wall (103) partitioning 102) from the outside is formed of a heat insulating wall.

According to the assembled battery device of the present invention, by providing the cooling passage formed in contact with one surface of the assembled battery member, the heat generated from the single battery cell can be effectively released to the outside through the cooling passage. That is, since the cooling passage is partitioned by a partition wall made of a heat insulating wall from the outside, the heat (temperature) of the external environment hardly affects the refrigerant in the cooling passage, and the refrigerant in the cooling passage Can always be kept at a predetermined cooling temperature. Therefore, the temperature difference between the temperature of the one surface in contact with the assembled battery member and the temperature of the cooling refrigerant in the cooling passage can be maintained large and stably, and the cooling efficiency of the single battery cell is improved.
(2) The heat conductive member (2) of the assembled battery device of the present invention includes a matrix base material (20) and a thermal conductivity in the length direction of the fibers contained in the matrix base material (20) of 10 W / It is preferable that it consists of a fiber member (21) of m · K or more.

The matrix substrate has a certain degree of deformability, and the fiber member is more rigid than the matrix substrate. Therefore, the deformation (thinning) of the heat conducting member can be prevented by the interposition of the fiber member, and the expansion of the single battery cell can be reliably regulated. Thereby, the internal pressure of each single battery cell can be made uniform, and the charge / discharge characteristics of each single battery cell can be made uniform. Moreover, a hard spacer becomes unnecessary by a fiber member, and the distance between single battery cells can be reduced. Therefore, the whole becomes a compact shape, and the mounting space can be reduced.
(3) The fibers constituting the fiber member (21) of the assembled battery device of the present invention are substantially parallel to the widest surface of the unit cell (1) and in a direction toward the cooling passage (102). It is preferably oriented.

If the fibers constituting the fiber member are oriented substantially parallel to the widest surface of the single battery cell and in the direction toward the cooling passage, the exhaust heat from the single battery cell passes through the fiber member of the heat conducting member. Since the heat is efficiently transferred in the direction toward the cooling passage and is radiated from the cooling passage, the heat dissipation is further improved.
(4) Between the surface of the said fiber member (21) and the surface of the said heat conductive member (2) of the assembled battery apparatus of this invention, the heat conductivity of a length direction is short of 10 W / m * K or more. It is preferable that the fibers (21c) are embedded while being oriented in the thickness direction of the heat conducting member (2).

By aligning and embedding short fibers in the thickness direction of the heat conducting member, the thermal conductivity is improved between the surface of the heat conducting member and the surface of the fiber member, so that the exhaust heat of the single battery cell is heated. It becomes easy to be transmitted from the surface of the conductive member to the fiber member, and heat dissipation is promoted. For this reason, the heat dissipation efficiency of the single battery cell is further improved.
(5) It is preferable that the said refrigerant | coolant of the assembled battery apparatus of this invention is air.
(6) A heat sink (4) in which a plurality of heat radiating plates are arranged in a row is arranged in the cooling passage (102) of the assembled battery device of the present invention, and a part of the heat conducting member (2) is the heat sink ( It is preferable that it is exposed so that heat can be transferred by being in close contact with 4).

By disposing the heat sink in the cooling passage, the exhaust heat from the single battery cell exchanges heat with the refrigerant in the cooling passage through the heat sink, so that the heat dissipation efficiency of the single battery cell is further improved.
(7) It is preferable that the said heat insulation wall of the assembled battery apparatus of this invention consists of heat insulating materials whose heat conductivity is 0.5 W / m * K or less.

Thereby, the refrigerant temperature in the cooling passage can be effectively protected from the external environment, and the cooling efficiency of the single battery cell is improved.
(8) It is preferable that the said heat insulating material of the assembled battery apparatus of this invention is resin or a resin foam.

  The symbols used in [Claims] and [Means for Solving the Problems] are for easy understanding of the configuration of the present invention, and are not limited to the embodiments.

  According to the assembled battery device of the present invention, the heat generated from the single battery cell can be effectively released to the outside through the cooling passage. Since the cooling passage is partitioned from the outside by a partition wall consisting of heat insulating walls, the heat (temperature) of the external environment is unlikely to affect the refrigerant in the cooling passage, and the refrigerant in the cooling passage is always set to a predetermined level. Can be kept at the cooling temperature. Therefore, the temperature difference between the temperature of the one surface in contact with the assembled battery member and the temperature of the cooling refrigerant flowing inside the cooling passage can be maintained large and stably, and the cooling efficiency of the single battery cell is improved. To do.

  Further, since there is no gap between the single battery cell and the heat conducting member, the problem of dust accumulation in the conventional space 904 does not occur. Therefore, even after long-term use, the cooling conditions for each single battery cell are almost the same, so that the cooling characteristics between the single battery cells can be made uniform, and the life is prolonged.

  Furthermore, by providing the heat conducting member and the cooling passage, the exhaust heat of the single battery cells can be efficiently released, and thus the distance between the single battery cells can be reduced. Therefore, the whole becomes a compact shape and the mounting space can be reduced. In addition, a part of the assembled battery member is exposed and installed in the cooling passage so that heat can be transferred, and since heat exchange is performed in the cooling passage, the position where condensation easily occurs is far from the electrode of the unit cell, Electric leakage due to condensation can also be prevented.

  The assembled battery device of the present invention is suitably used as a power supply device for electric vehicles, hybrid vehicles, and the like.

  The assembled battery device of the present invention includes an assembled battery member and a cooling passage.

  The assembled battery member includes a single battery cell and a plate-like heat conduction member, and the battery cells and the heat conduction member are in close contact with each other and are alternately arranged in a row, and are pressed from both ends in the row direction. Be bound.

  The cooling passage is formed in a tunnel shape in contact with one surface of the assembled battery member, and the refrigerant is circulated therein. At least a part of the heat conducting member is exposed inside the cooling passage, and the heat conducting member exchanges heat with the refrigerant in the cooling passage through the exposed portion. The partition wall that partitions the cooling passage from the outside is a heat insulating wall.

  As the heat insulating wall, it is desirable to use a heat insulating material having a thermal conductivity of 0.5 W / m · K or less. Among heat insulating materials, generally a resin having a thermal conductivity of 0.2 W / m · K or less (for example, a polyethylene resin or a polypropylene resin), or a resin having a lower thermal conductivity of 0.02 W / m · K or less. A foam (for example, a polyethylene resin foam, a polypropylene resin foam) or the like is preferably used.

  Since the partition wall of the cooling passage has heat insulation properties, the refrigerant flowing through the cooling passage is thermally protected from the outside. Therefore, the influence from an external heat source (for example, exhaust heat of a car) is reduced. It becomes easy to manage the refrigerant temperature in the cooling passage. Since the temperature difference during heat exchange can be kept large and stable, the heat from the single battery cell can be efficiently released.

  In the assembled battery device of the present invention, cooling air (cooling air) from an air conditioner can be used as the refrigerant. In addition to the cooling air, it is also possible to use a cooling oil having electrical insulation.

  In the assembled battery device of the present invention, a general so-called prismatic battery cell can be used as the single battery cell. You may use one with a resin casing, or one with an insulating coating on the surface, but use a single battery cell that exposes a metal casing such as iron or aluminum with high thermal conductivity. It is preferable. In general, a pair of electrodes project from the upper part of the unit cell. Usually, a plurality of unit cells are arranged in a row so that the sides having the electrodes are all the same side.

  A heat conductive member consists of a soft material which has heat conductivity and electrical insulation.

  A heat conductive member can consist of a matrix base material and the fiber member contained in the matrix base material. The matrix base material corresponds to a soft material. The heat conducting member is formed in a plate shape. Here, the degree of softness in the matrix base material constituting the heat conducting member is desirably 50 or less in Asker C hardness. By setting the Asker C hardness to a softness of 50 or less, sufficient adhesion with the widest side surface of the single battery cell can be secured, and the heat of the single battery cell can be efficiently radiated. The Asker C hardness is a rubber hardness defined by the Japan Rubber Association standard SRIS 0101 and corresponds to a Shore hardness E defined by JIS K 6253. The matrix base material preferably has a thermal conductivity of 5 W / m · K or more. If the thermal conductivity is lower than this, the heat dissipation becomes low, which is not preferable.

  As a material for the matrix base material having the above-described properties, for example, a thermoplastic elastomer such as silicone rubber can be used. Silicone rubber has both thermal conductivity and high electrical insulation, and is soft with an Asker C hardness of about 2-45. General rubber and thermoplastic elastomers cannot be used because they are too low in thermal conductivity as they are, but there is a possibility that they can be used by mixing high thermal conductive materials such as alumina, boron nitride, silicon nitride, and silica. is there.

  The fiber member preferably has a thermal conductivity of 10 W / m · K or more in the longitudinal direction of the fiber. The material of such a fiber member includes an ultrahigh molecular weight polyethylene fiber having a thermal conductivity of about 60 W / m · K in the longitudinal direction of the fiber, a carbon fiber having the same thermal conductivity of about 540 W / m · K, and the same heat. Aluminum fiber with a conductivity of about 240 W / m · K, alumina fiber with a thermal conductivity of about 1015 W / m · K, copper fiber with a thermal conductivity of about 400 W / m · K, and a thermal conductivity of about 300 Examples include aluminum nitride fibers of up to 400 W / m · K, titanium fibers having the same thermal conductivity of about 22 W / m · K, and boron nitride having the same thermal conductivity of about 250 W / m · K. Among them, an ultrahigh molecular weight polyethylene fiber having the same thermal conductivity of about 60 W / m · K is also a particularly preferable material because it has an electrical insulating property.

  Further, the fiber member can be composed of an aggregate of single fibers. Moreover, the direction along the direction toward the cooling passage is preferable as the orientation direction of the aggregate of single fibers. That is, even if the thermal conductivity of the single fiber is 10 W / m · K or more in the fiber length direction, it may be less than 10 W / m · K in the fiber radial direction. When a fiber member composed of an aggregate of single fibers is embedded in a matrix substrate, the single fiber aggregate that is conducted from the surface of the heat conducting member is oriented by orienting the aggregate of single fibers along the direction toward the cooling passage side. The exhaust heat of the battery cell is easily conducted along the orientation direction of the fiber member, and is concentrated on the cooling passage side while suppressing heat conduction (outflow) in directions other than the direction toward the cooling passage side. Heat can be transferred. Thereby, heat is efficiently transferred to the cooling passage side while suppressing the temperature rise in the environment surrounding the single battery cell, and heat dissipation is realized through the cooling passage. On the other hand, when a large amount of heat from the single battery cell flows in a direction other than the direction toward the cooling passage side, the temperature of the surrounding environment of the single battery cell rises, leading to deterioration of the single battery cell.

  Moreover, by embedding the fiber member in the matrix base material, the surface rigidity of the heat conducting member is increased, and the expansion of the single battery cell can be further suppressed.

  Moreover, it is desirable that the fiber member is contained in the heat conductive member in a range of 20 to 80% by volume. When the content of the fiber member is less than 20% by volume, the heat dissipation becomes insufficient. When the content is more than 80% by volume, the softness of the heat conducting member is lowered and the adhesiveness with the single battery cell is lowered. descend.

  In order to form the heat conducting member, it can be easily formed by injecting and press-molding a soft material such as silicone rubber in a molten state with the fiber member disposed in the mold. In this case, when forming the fiber member, a composite yarn composed of a single fiber having a thermal conductivity of 10 W / m · K or more in the length direction and a soft heat conductive resin layer coated on the surface of the single fiber is used. Is also preferable. If a soft heat conductive resin layer having high affinity with the matrix base material is used, the adhesion between the matrix base material and the fiber member is increased, and the heat dissipation is improved. In addition, if only a composite yarn consisting of a single fiber and a soft heat conductive resin layer coated on the surface of the single fiber is placed in a mold and press-molded, the soft heat conductive resin layer can be used as a matrix substrate. is there.

  However, as described above, when the heat conductive member is formed by press molding in which a soft material such as silicone rubber is injected, if the thermal conductivity of the silicone rubber is lower than that of the fiber member, the surface of the silicone rubber is transferred from the surface of the silicone rubber to the fiber member. There is a possibility that the amount of heat transfer is insufficient.

  Therefore, between the surface of the fiber member and the surface of the heat conducting member (or between the surfaces on both sides in the thickness direction of the heat conducting member), the thermal conductivity in the length direction is 10 W / m · K or more. It is desirable that the fiber length direction of the short fiber is embedded so as to be oriented in the thickness direction of the heat conducting member. If it does in this way, the heat transmitted from the single battery cell to the contact | adherence surface can be efficiently transferred to a fiber member via the short fiber oriented in the thickness direction, and heat dissipation is further improved.

  In order to form a heat conducting member with short fibers oriented in this way, a composite material in which short fibers are mixed with a soft material such as silicone rubber is formed. Then, when the fiber member is placed in the mold and the molten composite material is injected and molded, the molding is performed while applying a magnetic field in the thickness direction of the heat conducting member. Accordingly, the short fibers can be oriented in the fiber length direction parallel to the magnetic field direction and in the thickness direction of the heat conducting member.

  The material of the short fiber may be the same as that of the fiber member, or another material such as boron nitride that is easily oriented in the magnetic field direction may be used unlike the fiber member. Moreover, the shape of a short fiber can use not only a fibrous form but a scale-like thing. The content of the short fibers oriented in the thickness direction is preferably in the range of 20 to 60% by volume in the heat conducting member. If the content of the short fibers oriented in the thickness direction is less than 20% by volume, the above-mentioned effect is difficult to be obtained. Even if the content is more than 60% by volume, the effect is saturated and the rigidity of the heat conducting member becomes too high. As a result, the adhesiveness with the single battery cell is lowered and the heat dissipation is lowered.

  Moreover, you may form a heat conductive member in the bag shape which can accommodate a battery cell. If it does in this way, the laminated body of a single battery cell and a heat conductive member can be easily formed only by throwing a single battery cell in a bag-like heat conductive member.

  In addition, the surface of the heat conducting member that faces and closely contacts the single battery cell may be a convex spherical surface toward the single battery cell. In this way, when the pressure is restrained, the central portion of the spherical surface first comes into contact with the single battery cell, and as the area is compressed, the area of contact with the single battery cell increases from the center toward the outside. Air is prevented from remaining between the contact surface and the surface to be in close contact with, and heat dissipation is improved.

  In the assembled battery device of the present invention, a tab portion extending from a part (heat radiation surface) of the heat conducting member that is exposed in the cooling passage is formed, and the tab portions are arranged in the same direction. You may protrude in the inside of a cooling channel.

  In the above case, the battery cells and the heat conducting members that are alternately arranged and restrained under pressure are accommodated in the casing, and are exposed to the above heat radiating surface (inside the cooling passage so that heat can be transferred). A part of the heat conducting member) or the surface on which the tab portion protrudes comes into contact with the refrigerant in the cooling passage, and heat exchange can be performed. That is, the internal space of the tunnel-shaped cooling passage is used as a heat radiating space of the single battery cell. If the cool air of the air conditioner is circulated, the heat of each single battery cell is transferred to the heat radiating surface (the cooling passage of the heat conducting member). The heat can be evenly dissipated through the part) or the tab portion.

  Furthermore, a heat sink in which a plurality of heat radiating plates are arranged is arranged in a heat radiating space (inner space of the cooling passage), and a heat radiating surface of the heat conducting member (a part of the heat conducting member exposed inside the cooling passage) ) Is preferably brought into contact. If the cool air of the air conditioner is brought into contact with the heat sink, the heat of each single battery cell can be released more uniformly through the heat sink and the heat conducting member.

  In the case of using a heat sink, it is desirable to dispose the heat sink below the ones in which the battery cells and the heat conducting members are alternately arranged and restrained by pressure. In this way, even if dew condensation occurs in the heat sink, it is possible to prevent water droplets from coming into contact with the single battery cells, and it is possible to reliably prevent leakage.

  Moreover, a heat conductive member is formed in plate shape, and can be interposed between adjacent single battery cells. However, in this case, it is difficult to regulate the amount of compression of the heat conducting member, and there is a possibility that the amount of expansion differs between the battery cells on both sides of the heat conducting member. In addition, it is necessary to align (position) the assembly of single battery cells formed by stacking (by arrangement).

  Therefore, it is preferable to have a hard spacer having electrical insulation and capable of forming a space for storing the heat conducting member. Further, the hard spacer can be provided with an engaging portion that can be aligned (positioned). By interposing the hard spacer, it is possible to regulate the amount of compression of the heat conducting member. Furthermore, it is possible to align a stack of unit cells, and to assemble the unit cells or wire electrodes more easily.

  Further, the hard spacer can be formed of a pair of cap-shaped holding members having substantially the same shape. The holding member can be formed of an electrically insulating resin such as polypropylene (PP). By using the cap-shaped holding member for the hard spacer, the rectangular unit cell can be held and held from both sides. And the accommodation space of a heat conductive member can be formed between the adjacent battery cells by the thickness of a holding member. Therefore, the amount of compression of the heat conducting member can be regulated by the thickness of the wall portion of the hard spacer.

  In addition to the cap shape, a hard spacer can be formed in a plate shape. For example, a window portion penetrating in the thickness direction can be formed in a plate-like spacer, and the heat conducting member can be held in the window portion. As this holding method, it may be held by uneven engagement or the like, or may be held by insert molding in which a heat conductive member is placed in a mold and a spacer is formed. The thickness of the heat conducting member is about 0.2 mm to 2 mm thicker than the wall thickness of the surrounding hard spacer, and it is compressed by the single battery cell when restrained by pressure so that it becomes the same thickness as the spacer. It is desirable to configure.

  It is preferable that an electrical insulating regulating means for regulating the proximity of the widest side surfaces of adjacent unit cells is disposed on the heat conducting member. By doing in this way, expansion of a single battery cell can be controlled reliably, the internal pressure of each single battery cell can be made uniform, and the charge / discharge characteristics of each single battery cell can be made uniform. This regulating means may be formed integrally with the spacer, or may be formed by embedding a hard resin in the heat conducting member.

  Hereinafter, the present invention will be described specifically by way of examples.

(Example 1)
FIG. 1 is an exploded perspective conceptual diagram of an assembled battery device according to the present embodiment. FIG. 2: shows the principal part longitudinal cross-section conceptual diagram of the assembled battery apparatus which concerns on a present Example. FIG. 3 is a conceptual diagram of a longitudinal section at the II position shown in FIG.

  As shown in the figure, an assembled battery device according to the present embodiment mainly includes an assembled battery member 101 positioned above, and a cooling passage 102 positioned below and formed in contact with a lower surface of the assembled battery member 101. It consists of. A heat sink 4 is provided in the cooling passage 102.

(Battery material)
The assembled battery member 101 is configured as a laminated body in which a plurality of unit cells 1 each having a rectangular parallelepiped shape and a heat conductive member 2 formed in a plate shape are arranged in close contact with each other.

  Specifically, as shown in FIG. 2, a pair of holding members 6 formed of PP are installed on the end portion 130 (side surface 13) that forms the short side of the single battery cell 1.

  The holding member 6 is formed in a container shape (cap shape), and includes a housing recess 62 for inserting and housing the end portion 130 of the unit cell 1 from the opening side of the cap. That is, the cap-shaped holding member is attached so as to cover the end portion 130 of the unit cell 1.

  The housing recess 62 is formed substantially the same as the end portion 130 of the single battery cell 1. Thereby, the unit cell 1 is sandwiched and held by the holding member 6 from both sides.

  The holding member 6 includes a first engaging portion 63 and a second engaging portion 64 for determining the relative positions of the unit cells 1 arranged in a row. The first engaging portion 63 is formed in a convex shape, and the second engaging portion 64 is formed in a concave shape so as to be engaged with the first engaging portion 63. Thereby, when arranging the battery cells 1 held by the holding member 6, the first engaging portion 63 of the adjacent holding member 6 is connected to the second engaging portion 64 of the other adjacent holding member 6. By engaging with each other, it can be arranged in parallel. Moreover, the shift | offset | difference of the relative position of the single battery cells 1 arranged by the engagement relationship of the holding member 6 can be prevented.

  In the assembled battery member 101, the single battery cell 1 held by the holding member 6 and the heat conducting member 2 are opposed to each other with the widest surfaces 10 of the adjacent single battery cells 1 facing each other through the heat conducting member 2. In this way, several tens of rows are alternately arranged (in FIG. 3, abbreviated to three), and the rows are formed in parallel. Depending on the thickness of the side wall of the holding member 6, a space for accommodating the heat conducting member 2 is formed between the battery cells 1 adjacent in the row direction.

  Resin constraining plates 3 are arranged at both ends of the assembled battery members 101 arranged in a row, and the unit cell 1 and the heat conducting member 2 are pressed so as to be in close contact with each other by a constraining rod (not shown). It is restrained by. In this state, the entire assembled battery member 101 is housed in a casing made of an electrically insulating resin (not shown).

  In the unit cell 1, battery elements such as an electrode plate, a separator, and an electrolytic solution are housed in an aluminum casing. A pair of positive and negative electrodes 12 protrudes from the top of the housing. The housing has six surfaces, and the widest surfaces 10 are lined up so that they face each other.

  FIG. 4 is a conceptual diagram showing a state where the heat conducting member 2 is installed in close contact with the single battery cell 1. As shown in FIG. 4, the heat conducting member 2 includes a mat risk base material 20 and a fiber member 21.

  Specifically, the matrix substrate 20 is made of silicone rubber having an Asker C hardness of 45 and a thermal conductivity of 5 W / m · K.

  The fiber member 21 is composed of a single fiber 21 b and is embedded in the matrix substrate 20. The single fiber 21b is formed from ultra high molecular weight polyethylene fiber ("Dyneema" manufactured by Toyobo).

  Specifically, the single fiber 21 b constituting the fiber member 21 is embedded in a substantially central portion in the thickness direction of the mat risk base material 20. The fiber member 21 is embedded in the heat conducting member 2 in an amount of 50% by volume.

  As shown in FIG. 4, the heat conducting member 2 including the fiber member 21 is provided between the unit cells 1 in the arrangement direction and between the assembled battery member 101 (unit cell 1) and the cooling passage 102. Provided. In other words, the heat conducting member 2 includes a first member 201a arranged in the horizontal direction and a plurality of second members 201b arranged in the vertical direction. The first member 201a and the second member 201b are arranged orthogonal to each other.

  In the second member 201b, the single fibers 21b are oriented in a direction substantially parallel to the widest surface (side surface 10) of the single battery cell 1 and toward the cooling passage (102).

  As for the 1st member 201a, the short fiber 21c is arrange | positioned along the thickness direction of the 1st member 201a.

  In addition, you may further mix | blend a single fiber (not shown) with the 1st member 201a. That is, the single fibers may be installed so as to be oriented substantially parallel to the side surface 11 constituting the long side of the single battery cell 1. Specifically, the monofilament is composed of a woven fabric formed by weft yarn (not shown) and warp yarn (not shown), and can be embedded in a substantially central portion of the matrix base material 20 in the thickness direction. . By providing the first member 201a with the weft and the warp, the heat can be uniformly distributed in the surface direction and can be transferred to the heat sink 4 to further improve the heat dissipation.

  FIG. 5 is a conceptual cross-sectional view showing a state in which the heat conducting member 2 (first member 201a) is installed in close contact between the single battery cells 1 at the II-II position shown in FIG.

  6 shows a state in which the heat conducting member 2 (second member 201b) is installed in close contact between the single battery cell 1 (battery member 101) and the heat sink 4 at the position III-III shown in FIG. It is a longitudinal cross-sectional conceptual diagram.

  As shown in FIGS. 5 and 6, the heat conductive member 2 of the assembled battery device of the present example is made of a matrix base material 20 and an ultrahigh molecular weight polyethylene fiber (“Dyneema” manufactured by Toyobo Co., Ltd.) similar to the single fiber 21 b. The short fiber 21c is embedded and held. The short fiber 21c has its fiber length direction oriented parallel to the thickness direction of the heat conducting member 2. The short fibers 21c are contained in the heat conducting member 2 by 30 to 40% by volume.

  In order to manufacture the heat conducting member 2 (for example, the second member 201b), a composite material in which the short fibers 21c are mixed is formed. Then, when the fiber member 21 is placed in the mold and the composite material in a molten state is injected and press-molded, molding is performed while applying a magnetic field in the thickness direction of the heat conducting member 2. Thereby, the short fibers 21c can be oriented in the magnetic field direction and in the thickness direction of the heat conducting member 2.

  As shown in FIG. 4, the plate-shaped second member 201 b has the widest surface constituting the contact surface 22, and the surface perpendicular to the contact surface 22 and including the long side of the contact surface 22 serves as the heat dissipation surface 23. It is composed. In the second member 201 b, the single fiber 21 b is oriented toward the cooling passage 102, and the end surface is exposed to the heat dissipation surface 23.

  On the other hand, the widest surface of the first member 201 a constitutes the contact surface 22.

  As can be understood from FIG. 4, the heat radiating surface 23 of the second member 201b is in contact with one contact surface 22 of the first member 201a. The other contact surface 22 of the first member 201a is also in contact with the cooling passage 102 side. Therefore, the heat released from the widest surface 10 of the single battery cell 1 is efficiently transferred to the single fibers 21b by the short fibers 21c in the second member 201b, and the first members 201a along the orientation of the single fibers 21b. The heat is conducted to the heat sink 4 from the contact surface 22 of the first member 201a. Then, heat is transferred to the cooling passage 102 via the heat sink 4.

  Thus, by adding the short fibers 21c to the heat conducting member 2, heat conduction in the direction orthogonal to the direction of the single fibers 21b is promoted. Due to the thermal connection between the single fiber 21b and the short fiber 21c, the heat radiation from the single battery cell 1 can be effectively and uniformly released.

  Further, when pressure restraining is performed with a restraining rod (not shown) pressed from both sides with a predetermined load, the thickness of the heat conducting member 2 is compressed by the widest side surface 10 of the pair of adjacent unit cells 1. Since the second member 201b is soft with an Asker C hardness of 45, it is easily deformed by compression, and the contact surface of the first member 201a located at the widest side surface 10 of the unit cell 1 and the bottom of the unit cell 1 The thickness is reduced while being in close contact with 22. The surplus portion of the thinned portion is absorbed by further swelling into the space above the single battery cell 1.

  Even if the single battery cell 1 is about to thermally expand, the expansion can be reliably regulated because the expansion is regulated by the heat conducting member 2 and the holding member 6. Further, the interval between the unit cells 1 is determined by the thickness of the side wall of the holding member 6, and the interval between the unit cells 1 can be made narrower than in the case where a spacer having a conventional rib is interposed. Therefore, the mounting space can be reduced.

(Cooling passage)
The cooling passage 102 is formed in a tunnel shape with a partition wall 103 made of a heat insulating wall. Openings 1022 are formed at both ends of the cooling passage 102. Cooling air (refrigerant) from the air conditioner flows through the cooling passage 102 from one opening 1022 to the other opening 1022. Thus, the cooling passage 102 is thermally protected (insulated) from the outside.

  Further, an opening 1021 is formed in the partition wall 103 on the assembled battery member 101 side, and the heat sink 4 is installed (inserted) inside the cooling passage 102 through the opening 1021.

  Further, as shown in FIG. 2, a plate-like heat conducting member 2 (first member) is formed on a side surface (bottom surface) 11 that is orthogonal to the widest surface 10 of the unit cell 1 and includes the long side of the widest surface 10. A heat sink 4 is arranged with 201a) therebetween. The side surface 11 (bottom surface) of the single battery cell 1 is in close contact with the upper surface of the first member 201 a, and the lower surface of the first member 201 a is in close contact with the surface of the heat sink 4.

  The heat sink 4 is made of metal in which a plurality of heat radiating plates are arranged, and in this embodiment, the close contact surface 22 of the first member 201 a is in close contact with the heat sink 4.

  Thus, the heat sink 4 is inserted into the cooling passage 102 thermally insulated from the outside while being in close contact with the single cell member 101, and is in contact with the refrigerant.

  Further, as shown in FIG. 1, a rib 1023 is formed at the bottom of the cooling passage 102 along a direction that protrudes from the bottom and is orthogonal to the flow direction of the refrigerant. The heat sink 4 is disposed in contact with the rib portion 1023. As a result, the heat sink 4 can be stably disposed in the cooling passage 102, and at the same time, the flow of the cooling air can be adjusted, and the heat exchange performance in the heat sink 4 is further improved.

  In this embodiment, the heat sink 4 that is in close contact with the heat conducting member 2 is used. However, instead of the heat sink 4, a part of the heat conducting member 2 is exposed to the cooling passage 102, and heat exchange (heat radiation) is directly performed by cold air. You can also

  In this embodiment, the partition wall 103 is made of a highly heat-insulating polyethylene resin, but a higher heat-insulating material such as a resin foam (polyethylene resin foam or the like) is more preferable.

  Further, in this embodiment, it is not necessary to form a space for circulating cooling air as described in Patent Document 4 between the single battery cells 1, it is not necessary to interpose a hard spacer, and heat conduction is performed. The thickness of the member 2 may be thin. Therefore, the distance between the single battery cells 1 can be reduced, and the entire space becomes compact, so that the mounting space can be reduced.

  Moreover, in the assembled battery apparatus of a present Example, the position of the heat sink 4 is made into the downward direction of the single battery cell 1, as shown in a figure. For this reason, even if dew condensation occurs in the heat sink 4, it is possible to prevent water droplets from coming into contact with the single battery cell 1, and it is possible to reliably prevent leakage.

(Heat conduction member)
The fiber member 21 can be laminated in the thickness direction in the heat conductive member 2 with a single layer or multiple layers (shown in FIG. 5). Note that it is preferable to stack a plurality of layers. In this way, the total area of the end faces of the single fibers 21b exposed on the heat dissipation surface 23 can be further increased. Moreover, the distance from the contact | adherence surface 22 to the fiber member 21 becomes short. Therefore, heat dissipation is further improved.

  According to the assembled battery device of this example, the thermal conductivity of the matrix base material 20 is 5 W / m · K, the thermal conductivity in the longitudinal direction of the fibers of the fiber member 21 is 60 W / m · K, and the fibers The thermal conductivity in the short direction of the fibers of the member 21 is 3 W / m · K. Therefore, the heat of the single battery cell 1 is first transferred from the adhesion surface 22 to the matrix base material 20, and then transferred to the fiber member 21 through the inside of the matrix base material 20. And since the thermal conductivity in the longitudinal direction of the fiber is extremely high, heat is transferred from the single fiber 21b of the fiber member 21 to the heat sink 4 on the cooling passage side 102 and efficiently radiated from the heat sink 4.

  That is, according to the assembled battery device of the present embodiment, heat is radiated from the respective heat conducting members 2 under almost the same conditions. Can be made uniform.

  Further, since there is no gap between the single battery cell 1 and the heat conducting member 2, the problem of dust accumulation in the conventional space 104 does not occur. Therefore, even after long-term use, the heat dissipation of each single battery cell 1 is almost the same, so that the cooling characteristics between the single battery cells can be made uniform, and the life is extended.

(Example 2)
The assembled battery device of the present embodiment is basically the same as that of the first embodiment, and different parts will be described below.

  FIG. 7 shows a cross-sectional view of the heat conducting member of the assembled battery device of this example. As shown in FIG. 7, it is the same as that of Example 1 except that the heat conductive member 2 in which the fiber member 21 composed only of the single fiber 21b is embedded in the matrix substrate 20 is used. The manufacturing method will be described below.

  First, a coating layer 50 made of silicone rubber having a thermal conductivity of 5 W / m · K is formed on the surface of a single fiber 21b made of ultra-high molecular weight polyethylene fiber (“Dyneema” manufactured by Toyobo Co., Ltd.) similar to Example 1. A composite yarn 5 was prepared.

  Next, as shown in FIG. 7, a plurality of the composite yarns 5 are bundled and placed in a mold and heat-pressed to form the heat conducting member 2.

  According to the assembled battery device of the present embodiment, the adhesiveness between the single fibers 21b and the matrix base material 20 is further increased, so that the heat dissipation can be further improved.

1 is an exploded perspective conceptual diagram of an assembled battery device according to a first embodiment of the present invention. The principal part longitudinal cross-sectional conceptual diagram of the assembled battery apparatus which concerns on 1st Example of this invention is shown. The longitudinal cross-sectional conceptual diagram in the II position shown in FIG. 2 of the assembled battery apparatus which concerns on 1st Example of this invention is shown. It is a conceptual diagram which shows the state by which the heat conductive member was closely_contact | adhered and installed in the single battery cell of the assembled battery apparatus which concerns on 1st Example of this invention. FIG. 3 is a schematic cross-sectional view of the assembled battery device according to the first embodiment of the present invention at the II-II position shown in FIG. 3. FIG. 3 is a conceptual diagram of a longitudinal section at the position III-III shown in FIG. 3 of the assembled battery device according to the first embodiment of the present invention. The cross-sectional conceptual diagram of the heat conductive member of the assembled battery apparatus which concerns on 2nd Example of this invention is shown. It is a disassembled perspective conceptual diagram of the conventional assembled battery apparatus.

Explanation of symbols

1: Single battery cell 2: Thermal conduction member
20: Matrix 21: Fiber member
101: assembled battery member 102: cooling passage 103: partition wall

Claims (8)

A single battery cell (1) having a rectangular parallelepiped shape and a plurality of heat conduction members (2) formed in a plate shape from a soft material having thermal conductivity and electrical insulation are alternately arranged in a row. An assembled battery member (101) that is pressure-constrained from both ends in the row direction,
A tunnel-shaped cooling passage (102) formed in contact with one surface of the assembled battery member (101) and through which a refrigerant flows,
At least a part of the heat conducting member (2) is exposed to the inside of the cooling passage (102) so that heat can be transferred, and a partition wall (103) that partitions the cooling passage (102) from the outside is a heat insulating wall. An assembled battery device.   The heat conducting member (2) includes a matrix base material (20) and a fiber member (21) that is contained in the matrix base material (20) and has a thermal conductivity in the length direction of 10 W / m · K or more. The assembled battery device according to claim 1, comprising:   The group according to claim 2, wherein the fibers constituting the fiber member (21) are oriented in a direction substantially parallel to the widest surface of the single battery cell (1) and toward the cooling passage (102). Battery device.   Between the surface of the said fiber member (21) and the surface of the said heat conductive member (2), the short fiber (21c) whose heat conductivity of a length direction is 10 W / m * K or more is the said heat conductive member ( The assembled battery device according to any one of claims 2 to 3, wherein the assembled battery device is embedded while being oriented in a thickness direction of 2).   The assembled battery device according to any one of claims 1 to 4, wherein the refrigerant is air.   A heat sink (4) in which a plurality of heat radiating plates are arranged is arranged in the cooling passage (102), and a part of the heat conducting member (2) can transfer heat by being in close contact with the heat sink (4). The assembled battery device according to any one of claims 1 to 5, wherein   The assembled battery device according to any one of claims 1 to 6, wherein the heat insulating wall is made of a heat insulating material having a thermal conductivity of 0.5 W / m · K or less.   The assembled battery device according to claim 7, wherein the heat insulating material is a resin or a resin foam.

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