JP2010015951A - Energy storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an energy storage device of which a size in the direction of arranging housing chambers can be reduced in a structure with the two housing chambers. <P>SOLUTION: The energy storage device includes a liquid heat exchange medium for exchanging heat with electric energy storage elements 21, a first housing chamber R1 for housing an electric storage module 20, and a second housing chamber R2 arranged adjacent to the first housing chamber in the direction perpendicular to a gravity direction. One of the first and second housing chambers is formed of a recess which opens to an upper surface of the housing chamber and a cover member for closing an opening of the recess. The other housing chamber is formed of a recess opened to a bottom of the housing chamber, and a cover member for closing the opening of the recess. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power storage device that houses a power storage module including a plurality of power storage elements.

In a battery pack including a secondary battery, a case having a storage chamber for storing the secondary battery and a storage chamber different from the storage chamber may be used. Here, the two cases described above are partitioned from each other.
Japanese Utility Model Publication No. 55-168969 (Fig. 2) JP 2001-135287 A International Publication No. 98/32186 Pamphlet

  However, in a case having two storage chambers, when these storage chambers are formed using a mold, the case may be enlarged. Specifically, a draft is generated on the wall surfaces of adjacent storage chambers, and the case becomes large in the direction in which the two storage chambers are arranged.

  Accordingly, an object of the present invention is to provide a power storage device that can be reduced in size in a direction in which these storage chambers are arranged in a configuration including two storage chambers.

  A power storage device according to the present invention includes a power storage module including a plurality of power storage elements, a liquid heat exchange medium that performs heat exchange with the power storage elements, a first storage chamber that stores the power storage module, a gravity direction, And a second storage chamber disposed adjacent to the first storage chamber in a direction perpendicular to the first storage chamber. One of the first and second storage chambers is composed of a recess having a shape that opens toward the upper surface of the storage chamber, and a lid member that closes the opening of the recess. The storage chamber is composed of a recess having a shape that opens toward the bottom surface of the storage chamber, and a lid member that closes the opening of the recess.

  Here, a valve that changes from the closed state to the open state and moves at least gas generated from the power storage element to the second storage chamber can be provided between the first and second storage chambers. Further, the first storage chamber is constituted by a first region that stores the power storage module and the heat exchange medium, and a second region that is located above the second storage chamber and stores the heat exchange medium. Can do. In this configuration, a valve can be provided in a region of the second storage chamber that faces the upper surface of the first storage chamber. A guide portion may be provided that extends upward with respect to the valve and forms a passage through which the heat exchange medium and the gas move to the second storage chamber. Thereby, the quantity of the heat exchange medium which moves from the first storage chamber to the second storage chamber can be reduced.

  An uneven portion can be formed in at least one of the inner wall surface and the outer wall surface in the first storage chamber. Thereby, the intensity | strength in a 1st storage chamber can be improved, or the heat transfer through a 1st storage chamber can be accelerated | stimulated.

  A portion of the second storage chamber located on the outer surface of the power storage device can be formed of resin. Thereby, for example, when excessive heat is applied from the outside of the power storage device, the portion formed of the resin in the second storage chamber can be melted. And the gas which moved to the 2nd storage chamber can be escaped outside from the part which resin melt | dissolved. Further, by providing a valve in the second storage chamber, the gas moved to the second storage chamber can be released to the outside of the power storage device. Here, the valve may be any valve that changes from the closed state to the open state when the temperature of the power storage device becomes equal to or higher than a predetermined value. Specifically, the valve can be changed from a closed state to an open state in accordance with a temperature change. Further, it is possible to determine that the temperature of the power storage device has become equal to or higher than a predetermined value, and to output a drive signal to the valve to change from the closed state to the open state.

  A connector for electrically connecting the power storage module and the device accommodated in the second accommodation chamber can be disposed between the first and second accommodation chambers. Thereby, the apparatus electrically connected with an electrical storage module can be arrange | positioned using a 2nd storage chamber, and a 2nd storage chamber can be used effectively.

  Here, in the configuration in which the connector is fixed to the first or second storage chamber, the fixing of the connector is released in response to an increase in the internal pressure of the first storage chamber due to the generation of gas. it can. Thereby, the gas generated in the first storage chamber can be moved to the second storage chamber using the portion where the connector is disposed. In addition, if the connector is formed of resin, the connector can be melted by this heat when excessive heat is applied from the outside of the power storage device. Thereby, the gas generated in the first storage chamber can be moved to the second storage chamber using the portion where the connector is disposed.

  In the power storage module, a monitoring unit for monitoring the state of the power storage element can be provided. As a result, the monitoring unit is arranged in the first accommodation chamber. Here, since the number of wirings corresponding to the plurality of power storage elements is connected to the monitoring unit, by arranging the monitoring unit in the first storage chamber, the outside of the first storage chamber The number of wires drawn from the monitoring unit can be reduced.

  In this invention, the recessed part which comprises a part of 1st and 2nd storage chamber is made into the shape opened toward the mutually different direction. As a result, when forming the recesses in the first and second storage chambers using the mold, the draft surfaces of these recesses can be positioned substantially in parallel, and the first and second storages The space between the chambers can be reduced. Therefore, the power storage device can be reduced in size in a direction orthogonal to the direction of gravity.

  Examples of the present invention will be described below.

  A configuration of a battery pack (power storage device) that is Embodiment 1 of the present invention will be described with reference to the drawings.

  The battery pack of this embodiment is mounted on a vehicle. Such vehicles include hybrid vehicles and electric vehicles. A hybrid vehicle is a vehicle provided with other power sources such as an internal combustion engine and a fuel cell that output energy used for traveling of the vehicle in addition to the battery pack. An electric vehicle is a vehicle that travels using only the output of the battery pack. The battery pack according to the present embodiment outputs energy used for running the vehicle by discharging, or charges kinetic energy generated during braking of the vehicle as regenerative power. It is also possible to perform charging by receiving power supply from the outside of the vehicle.

  FIG. 1 is an exploded perspective view of the battery pack according to the present embodiment. FIG. 2 is a top view showing a partial configuration inside the battery pack according to the present embodiment.

  A pack case 10 constituting the exterior of the battery pack 1 has a lower case 11 and an upper case 12. The upper case 12 is fixed to the lower case 11 using a fastening member 13 such as a bolt. Here, a plurality of openings 11 a and 12 a for fastening the fastening member 13 are formed in the outer edge portions of the upper case 12 and the lower case 11. The method of fixing the upper case 12 to the lower case 11 is not limited to the method using the fastening member 13, and any method may be used. For example, the upper case 12 and the lower case 11 can be fixed by welding.

  The lower case 11 and the upper case 12 are preferably formed of a material having excellent durability and corrosion resistance. Specifically, a metal such as aluminum or iron can be used as this material.

  The lower case 11 is fixed to a vehicle body (not shown) by a fastening member, welding, or the like. Here, examples of the vehicle body include a floor panel, a floor pan, and a vehicle frame (so-called side members and cross members). Further, the lower case 11 has a space for accommodating the battery module (storage module) 20. In this space, the battery module 20 and the liquid heat exchange medium 3 having insulation properties are accommodated.

  The heat exchange medium 3 comes into contact with the surface of the battery module 20 and the inner wall surface of the pack case 10 (the lower case 11 and the upper case 12). That is, the heat exchange medium 3 is filled in a specific internal space in the pack case 10 with almost no gap. The heat exchange medium 3 is used to cool or warm the battery module 20.

  Here, when the battery module 20 (single cell 21 to be described later) generates heat due to charge / discharge or the like, the heat exchange medium 3 in contact with the battery module 20 exchanges heat with the battery module 20, thereby Take away heat. Thereby, the temperature rise of the battery module 20 can be suppressed. The heat exchange medium 3 having heat transfers heat to the pack case 10 by contacting the pack case 10. This heat is released to the outside through the pack case 10.

  On the other hand, if heat is applied from the outside of the battery pack 1, this heat is transferred to the heat exchange medium 3 via the pack case 10 and then transferred to the battery module 20 via the heat exchange medium 3. Thereby, it can suppress that the battery module 20 cools too much. Here, since the heat exchange medium 3 is composed of a liquid, it has a higher thermal conductivity than the case where gas is used, and can efficiently heat and cool the battery module 20 described above.

  It is known that the unit cell 21 constituting the battery module 20 can obtain desired output characteristics in a predetermined temperature range (for example, 10 ° C. to 60 ° C.). Therefore, as described above, it is possible to prevent the output characteristics of the unit cell 21 from being deteriorated by warming or cooling the battery module 20. Specifically, when the temperature of the unit cell 21 is lower than the lower limit value of the temperature range, the unit cell 21 is warmed, and when the temperature of the unit cell 21 is higher than the upper limit value of the temperature range, The battery 21 may be cooled.

  As the heat exchange medium 3, an insulating oil or an inert liquid can be used. As the insulating oil, for example, silicon oil is used. Further, as the inert liquid (insulating liquid), for example, Fluorinert, Novec HFE (hydrofluoroether), and Novec 1230 (manufactured by 3M), which are fluorine-based inert liquids, can be used. If an insulating film is formed on the outer surface of the battery module 20, a liquid (for example, water) that is not excellent in insulation can be used as the heat exchange medium 3.

  Next, the configuration of the battery module 20 will be described.

  The battery module 20 includes a plurality of unit cells (storage elements) 21 and two support plates 22 for supporting these unit cells 21. The plurality of single cells 21 are arranged side by side in a plane substantially parallel to the support plate 22. The unit cell 21 has a power generation element and a battery case that houses the power generation element. Here, the power generation element is an element used for charging and discharging, and includes a positive electrode plate, a negative electrode plate, and an electrolyte (electrolytic solution or solid electrolyte).

  The two support plates 22 support both end sides of each unit cell 21. In addition, protrusions 22 a are provided on the upper end surface and the lower end surface of each support plate 22. Between the protrusion 22a provided on the upper end surface of the support plate 22 and the upper case 12, an elastic member 23 such as rubber is disposed. An elastic member 23 such as rubber is disposed between the protrusion 22 a provided on the lower end surface of the support plate 22 and the bottom surface of the lower case 11. And the battery module 20 can be positioned inside the pack case 10 by elastically deforming the elastic member 23.

  Positive and negative terminals (not shown) are respectively provided at both ends of each unit cell 21, and the terminals of each unit cell 21 are bus bars (not shown) with respect to the terminals of the adjacent unit cells 21. ) Through electrical and mechanical connections. In other words, the plurality of single cells 21 are electrically connected in series via the bus bar so that a high output (for example, 200 [V]) can be obtained. In addition, the cell 21 electrically connected in parallel may be included.

  A positive electrode bus bar 24 and a negative electrode bus bar 25 are electrically connected to an assembled battery including a plurality of unit cells 21, respectively. Specifically, the positive bus bar 24 is electrically connected to the total positive terminal (the positive terminal of the specific unit cell 21) in the assembled battery. In addition, the negative bus bar 25 is electrically connected to the total negative terminal of the battery pack (the negative terminal of another specific unit cell 21). The bus bars 24 and 25 are fixed to the connector 33.

  In this embodiment, a cylindrical secondary battery is used as the single battery 21. Examples of the secondary battery include a nickel metal hydride battery and a lithium ion battery. The shape of the unit cell 21 is not limited to a cylindrical shape, and may be other shapes such as a square shape. In this embodiment, a secondary battery is used. However, an electric double layer capacitor as a power storage element can be used instead of the secondary battery.

  On the other hand, a battery monitoring unit 30 is attached to a surface of the support plate 22 that faces the side surface of the lower case 11. The battery monitoring unit 30 is used for monitoring the state of the unit cell 21 such as the temperature, current value, and voltage value of the unit cell 21. The battery monitoring unit 30 is connected with a cable 31 for taking out information obtained by the battery monitoring unit 30 to the outside. One end 31 a of the cable 31 is electrically and mechanically connected to one end 32 a of the cable 32 provided in the connector 33.

  As shown in FIG. 3, the battery pack 1 of the present embodiment includes a storage chamber (first storage chamber) R1 that stores the heat exchange medium 3 and the battery module 20, and gas generated in the storage chamber R1. 1 and a separation chamber (second storage chamber) R2 for separating the gas and the heat exchange medium 3 when discharged to the outside. Here, FIG. 3 is an AA cross-sectional view in FIG. Further, the separation chamber R2 becomes a space for accommodating the heat exchange medium 3 leaking from the accommodation chamber R1.

  The storage chamber R1 and the separation chamber R2 are partitioned by a partition portion 11b that is a part of the lower case 11. Further, in the separation chamber R2, the other surface excluding the bottom surface is configured by the partition portion 11b. And a part of partition part 11b is located in the same surface as the upper case 12, as shown in FIG. Here, the storage chamber R1 and the separation chamber R2 are arranged adjacent to each other in a plane perpendicular to the direction of gravity. A part of the storage chamber R1 is located above the separation chamber R2 and stores the heat exchange medium 3.

  A cylindrical guide portion 11c is integrally formed on the upper surface of the partition portion 11b. The guide portion 11c extends in the direction of gravity and is provided to guide the gas generated in the storage chamber R1 to the separation chamber R2, as will be described later. The distal end of the guide portion 11 c is located away from the inner wall surface of the upper case 12. Here, the heat exchange medium 3 has also entered the guide portion 11c.

  In addition, the shape of the guide part 11c is not restricted to a cylindrical shape. That is, the guide portion 11c may have any shape provided with a passage (flow path) extending in the gravitational direction, and the cross-sectional shape in a horizontal plane orthogonal to the gravitational direction may be any shape. Moreover, the guide part 11c does not need to extend along the gravity direction, and may be inclined with respect to the gravity direction.

  A valve 40 is provided at one end of the guide portion 11c. As shown in FIG. 3, when the valve 40 is in the closed state, the heat exchange medium 3 that has entered the guide portion 11c is prevented from moving to the separation chamber R2. Further, when the valve 40 is opened, the heat exchange medium 3 in the storage chamber R1 enters the separation chamber R2 through the guide portion 11c.

  In the battery pack 1 of the present embodiment, as shown in FIG. 3, the upper surface and the lower surface of the pack case 10 can be configured as substantially flat surfaces. The length (height) of the battery pack 1 in the direction of gravity can be made approximately equal to the length of the battery module 20 in the direction of gravity. Thereby, compared with the structure described in Patent Document 1, the battery pack 1 can be reduced in size in the direction of gravity.

  Next, members disposed in the separation chamber R2 will be described with reference to FIGS. Here, FIG. 4 is an exploded perspective view of the battery pack of the present embodiment. FIG. 5 is a diagram of the battery pack according to the present embodiment as viewed from the bottom, and is a diagram illustrating a configuration in the separation chamber.

  A bottom cover 11 d is fixed to the partition portion 11 b of the lower case 11 by a fastening member 13 such as a bolt. As a result, the separation chamber R2 is surrounded by the partition portion 11b and the bottom lid 11d and is in a sealed state.

  As for the cable 32 provided in the connector 33, a part area | region is located in accommodation chamber R1, and another area | region is located in separation chamber R2. The other end of the cable 32 located in the separation chamber R2 is connected to a junction box 41 disposed in the separation chamber R2. Specifically, the cable 32 is electrically connected to a device (for example, a connector) disposed in the junction box 41.

  A cable 34 is electrically connected to the device to which the cable 32 is connected, and the cable 34 passes through the lower case 11 and extends to the outside of the battery pack 1. Here, as shown in FIG. 4, a seal member 35 is disposed in a portion of the lower case 11 through which the cable 34 passes, and the separation chamber R <b> 2 is sealed. The junction box 41 is fixed to the partition portion 11b by the fastening member 13.

  On the other hand, the connector 33 is disposed in a state of penetrating the partition portion 11b, and is fixed to the partition portion 11b by the fastening member 13 from the separation chamber R2 side. Here, the connector 33 can also be fixed to the partition part 11b from the storage chamber R1 side. Further, a positive electrode tab 42 a and a negative electrode tab 42 b provided at one end of the bus bar 42 are fixed to a portion of the connector 33 located in the separation chamber R 2. The bus bar 42 is disposed in the separation chamber R2.

  The positive electrode tab 42a and the negative electrode tab 42b are electrically connected to the positive and negative electrode bus bars 24 and 25 disposed in the accommodation chamber R1 via the connector 33, respectively. The bus bar 42 extends along the side surface of the partition 11b, and has a positive electrode tab 42c and a negative electrode tab 42d connected to the junction box 41 at the other end. The positive electrode tab 42 c and the negative electrode tab 42 d are electrically connected to the positive electrode bus bar 43 a and the negative electrode bus bar 43 b through devices arranged in the junction box 41.

  The bus bars 43 a and 43 b penetrate the lower case 11, and part of the bus bars 43 a and 43 b protrudes outside the battery pack 1. Cables (not shown) are connected to the bus bars 43a and 43b protruding to the outside of the battery pack 1, and the output of the assembled battery in the battery module 20 can be taken out. This cable can be connected to, for example, an inverter for driving a vehicle driving motor. Examples of the device in the junction box 41 that is electrically connected to the positive electrode tab 42c and the negative electrode tab 42d include a DC / DC converter and a relay switch.

  On the other hand, an exhaust duct 44 is connected to the upper portion of the separation chamber R <b> 2, and the exhaust duct 44 projects from the outer surface of the lower case 11. As will be described later, the exhaust duct 44 is used to discharge the gas that has entered the separation chamber R2 to the outside of the battery pack 1. Another end (not shown) for guiding the gas to the outside of the vehicle is connected to the end of the exhaust duct 44. The other duct and the exhaust duct 44 may be integrally formed. Here, as in the present embodiment, by configuring the other duct and the exhaust duct 44 separately, the battery pack 1 can be easily mounted on the vehicle, and the arrangement of the ducts connected to the exhaust duct 44 is arranged. Can be easily performed.

  Next, a mechanism for releasing the gas generated from the unit cell 21 to the outside of the battery pack 1 will be described.

  If the unit cell 21 is overcharged or overdischarged, gas may be generated from the power generation element housed inside the unit cell 21. Here, in the battery cell 21, a battery case that houses the power generation element is provided with a valve for releasing the gas generated by the power generation element to the outside of the battery cell 21.

  As this valve, a return type valve or a destructive type valve can be used. The return type valve is a valve that switches between an open state and a closed state according to the magnitude relationship between the internal pressure and the external pressure of the unit cell 21. The destructive valve is a valve that changes from a closed state to an open state by plastic deformation when the internal pressure of the unit cell 21 becomes higher than the external pressure. This destructive valve cannot be returned to the closed state when the valve is changed to the open state. This valve may be provided at any position in the unit cell 21 (battery case).

  When gas is released from the unit cell 21, this gas is accumulated in the storage chamber R <b> 1 in the pack case 10. As a result, the internal pressure in the storage chamber R1 increases, and the internal pressure in the storage chamber R1 becomes higher than the internal pressure in the separation chamber R2.

  Here, when the internal pressure of the storage chamber R1 reaches a predetermined value at which the operating pressure of the valve 40 is reached, the valve 40 changes from a closed state to an open state, and the heat exchange medium 3 that has entered the guide portion 11c enters the separation chamber R2. Will be moved to. Here, as the valve 40, a return type valve or a destructive type valve can be used in the same manner as the valve provided in the unit cell 21 described above. The operating pressure of the valve 40 can be set as appropriate. Specifically, it is necessary to change the valve 40 from the closed state to the open state before the pack case 10 breaks due to an increase in the internal pressure of the storage chamber R1 in the pack case 10.

  When the valve 40 changes to the open state, the heat exchange medium 3 moves into the separation chamber R2 through the guide portion 11c, and the gas released from the unit cell 21 moves into the separation chamber R2 through the guide portion 11c. Will do.

  Here, the gas released from the unit cell 21 proceeds in the direction opposite to the direction in which gravity acts (upward). That is, the gas from the unit cell 21 moves toward the upper case 12 side. However, when the amount of gas released from the unit cell 21 is large, this gas also enters the inside of the guide portion 11c and moves to the separation chamber R2.

  When the heat exchange medium 3 and the gas move to the separation chamber R2 through the guide portion 11c, the heat exchange medium 3 is collected at the bottom of the separation chamber R2 due to the action of gravity. Will move to the top. As a result, the heat exchange medium 3 and the gas are separated in the separation chamber R2. Since the exhaust duct 44 is connected to the upper portion of the separation chamber R2, the gas moves to the outside of the separation chamber R2 via the exhaust duct 44.

  Here, the position where the exhaust duct 44 is provided can be set as appropriate. In the present embodiment, the exhaust duct 44 is connected to the upper portion of the separation chamber R2, but the exhaust duct 44 can also be disposed below this position. In this case, in order to prevent the heat exchange medium 3 from being discharged to the outside of the vehicle through the exhaust duct 44, the exhaust duct 44 is preferably tilted upward. Thereby, the heat exchange medium 3 and gas can be separated using gravity.

  Further, a separation membrane for separating the heat exchange medium 3 and the gas may be provided in the exhaust duct 44 or in the separation chamber R2. The separation membrane may have any configuration as long as it prevents passage of the heat exchange medium 3 and allows passage of gas.

  On the other hand, in the present embodiment, the cylindrical guide portion 11c is provided, but the guide portion 11c may not be provided. That is, in the structure shown in FIG. 3, the upper surface which opposes the upper case 12 among the partition parts 11b can also be comprised with a flat surface. In this case, the valve 40 is provided in a partial region on the upper surface of the partition portion 11b.

  In the present embodiment, since the storage chamber R1 and the separation chamber R2 are arranged side by side in a horizontal plane orthogonal to the gravity direction, the battery pack 1 can be reduced in size in the gravity direction. Here, when the configuration described in Patent Document 1 is used, a valve or a duct for discharging gas is disposed above the battery module 20, and the battery pack 1 is enlarged in the direction of gravity. On the other hand, in the present embodiment, since the gas can be discharged from the side surface of the battery pack 1, the battery pack 1 can be downsized in the direction of gravity compared to the configuration described in Patent Document 1. it can.

  When the battery pack 1 is mounted on a vehicle as in this embodiment, it is meaningful to downsize the battery pack 1 in the direction of gravity (in other words, the vertical direction of the vehicle). That is, when the battery pack 1 is mounted on a vehicle, the battery pack 1 may be arranged on the floor panel of the vehicle. If the battery pack 1 is downsized in the direction of gravity, the battery pack 1 can be arranged on the floor panel or the like. The upper space of 1 can be used efficiently.

  Specifically, the battery pack 1 can be arranged using a space formed below a seat mounted on the vehicle. Further, even when the battery pack 1 is arranged in the lower part of the luggage room of the vehicle, the space of the luggage room located above the battery pack 1 can be efficiently used.

  On the other hand, by providing the guide portion 11c as in this embodiment, the amount of the heat exchange medium 3 that moves to the separation chamber R2 via the guide portion 11c can be reduced. Here, when the gas is released into the storage chamber R <b> 1 in the pack case 10, the gas accumulates along the inner wall surface of the upper case 12. At this time, if the valve 40 changes from a closed state to an open state due to an increase in the internal pressure of the storage chamber R1, the heat exchange medium 3 and gas move into the separation chamber R2 via the guide portion 11c.

  Thereby, the liquid level of the heat exchange medium 3 accommodated in accommodation chamber R1 falls. In other words, the liquid level of the heat exchange medium 3 is separated from the inner wall surface of the upper case 12. Here, since the guide portion 11c extends in the direction of gravity and the tip of the guide portion 11c is located in the vicinity of the upper case 12, the liquid level of the heat exchange medium 3 is lowered, so that the inside of the guide portion 11c. It becomes difficult for the heat exchange medium 3 to move. That is, it becomes difficult for the heat exchange medium 3 to move to the separation chamber R2.

  In particular, when the liquid level of the heat exchange medium 3 is lower than the tip of the guide portion 11c, the gas generated from the unit cell 21 mainly moves inside the guide portion 11c. . Thereby, the gas is mainly led to the separation chamber R2.

  As described above, the separation chamber R2 can be reduced in size by reducing the amount of the heat exchange medium 3 guided to the separation chamber R2. Here, when the guide part 11c is not provided, the amount of the heat exchange medium 3 guided to the separation chamber R2 increases. In such a case, it is necessary to prevent the heat exchange medium 3 from overflowing from the separation chamber R2 and leaking outside the vehicle via the exhaust duct 44. Specifically, it is necessary to provide a space in the separation chamber R2 that can sufficiently accommodate the amount of the heat exchange medium 3.

  On the other hand, by using the guide portion 11c as in this embodiment, the separation chamber R2 can be reduced in size, and the battery pack 1 can be reduced in size. Moreover, the gas generated in the storage chamber R1 can be efficiently discharged outside the battery pack 1 using the separation chamber R2.

  Here, the position of the tip of the guide portion 11c, in other words, the length of the guide portion 11c in the direction of gravity can be set as appropriate. That is, as the length of the guide portion 11c is increased, the amount of the heat exchange medium 3 guided to the separation chamber R2 via the guide portion 11c is reduced. Further, as the length of the guide portion 11c is shortened, the amount of the heat exchange medium 3 guided to the separation chamber R2 through the guide portion 11c increases. On the other hand, the distance between the tip of the guide portion 11c and the inner wall surface of the upper case 12 is a distance that allows the gas released into the storage chamber R1 and the heat exchange medium 3 to move into the guide portion 11c. preferable. Considering this point, the length of the guide portion 11c can be set.

  On the other hand, a flange extending radially outward of the guide portion 11c can be provided at the tip of the guide portion 11c. By providing such a flange, even when the battery pack 1 is shaken when the liquid level of the heat exchange medium 3 is lower than the tip of the guide part 11c, the heat exchange medium 3 enters the inside of the guide part 11c. Can be prevented.

  In addition, a strainer can be disposed at the tip of the guide portion 11c. The strainer has a plurality of openings that are smaller than the openings of the guide portion 11c, allows the gas and the heat exchange medium 3 to enter the guide portion 11c, and foreign matter excluding the gas and the heat exchange medium 3 guides it. Used to prevent entry into the portion 11c. By providing the strainer, foreign matter can be prevented from entering the guide portion 11c, and the inside of the guide portion 11c can be prevented from being clogged with foreign matter.

  On the other hand, in the present embodiment, the storage chamber R1 and the separation chamber R2 have openings at different positions in the direction of gravity. That is, the opening of the storage chamber R1 is located on the upper surface of the battery pack 1 and is closed by the upper case 12. The opening of the separation chamber R2 is located on the bottom surface of the battery pack 1 and is closed by the bottom lid 11d.

  In such a structure, the thickness of the partition part 11b which partitions off the storage chamber R1 and the separation chamber R2 can be reduced. Hereinafter, this will be specifically described with reference to FIGS. 6A and 6B.

  In this embodiment, the lower case 11 constitutes a part of the storage chamber R1 and the separation chamber R2. Here, when the lower case 11 is molded using a mold, it is necessary to provide a draft to the lower case 11.

  As shown in FIG. 6A, when a molded product having two spaces E1 and E2 is processed, if molding is performed from the same direction (upper side in FIG. 6A) using a mold, a wall in the molded product 100 is caused by a draft. The thickness of the part 101 is D1. Here, the wall part 101 is a part located between the space parts E1 and E2. Moreover, the molded product 100 has a length L1.

  On the other hand, as shown in FIG. 6B, when molding is performed using a mold from different directions, a side surface (draft surface) constituting the space E1 and a side surface (draft surface) constituting the space E2 are formed. , Almost parallel. And since the recessed part which comprises the space part E1 has a draft side, it has the shape opened upwards. Moreover, the recessed part which comprises the space part E2 has the shape opened toward the downward direction. The open shape here refers to a shape in which the opening area increases from one end to the other end.

  In the molded article 102 shown in FIG. 6B, the thickness D2 of the wall 103 can be made thinner than the thickness D1 of the wall 101 shown in FIG. 6A. Accordingly, the length L2 of the molded product 102 can be made shorter than the length L1 of the molded product 100 shown in FIG. 6A.

  In the present embodiment, as described above, the openings in the storage chamber R1 and the separation chamber R2 are at different positions. The storage chamber R1 and the separation chamber R2 correspond to the space portions E1 and E2 in the molded product 102 shown in FIG. 6B. Moreover, the partition part 11b in a present Example, specifically, the part extended in the gravitational direction among the partition parts 11b is equivalent to the wall part 103 shown to FIG. 6B.

  For this reason, if the lower case 11 is formed using a mold, the draft surface constituting a part of the storage chamber R1 and the draft surface constituting a part of the separation chamber R2 are substantially parallel to each other. Therefore, the thickness of the partition portion 11b can be reduced. Accordingly, the battery pack 1 of the present embodiment can be downsized in the direction orthogonal to the direction of gravity.

  Here, in the present embodiment, as shown in FIG. 3, a part of the storage chamber R1 is positioned above the separation chamber R2, but this is not restrictive. For example, the battery pack can be configured as shown in FIG. Here, FIG. 7 is a schematic diagram showing the internal configuration of the battery pack, and corresponds to FIG. In FIG. 7, the same reference numerals are used for members having the same functions as those described in this embodiment.

  In the configuration shown in FIG. 7, the storage chamber R1 and the separation chamber R2 are arranged side by side in a direction orthogonal to the direction of gravity. That is, in this embodiment, as shown in FIG. 3, a part of the storage chamber R1 is positioned above the separation chamber R2, but in the configuration shown in FIG. 7, a part of the storage chamber R1 is separated from the separation chamber R2. It is not located above. Further, the storage chamber R1 has a concave portion that opens upward, and the opening in the concave portion is closed by the upper case 12. Furthermore, the separation chamber R2 has a concave portion that opens downward, and the opening in the concave portion is closed by the bottom lid 11d.

  In the configuration shown in FIG. 7, the valve 40 is provided in the partition portion 11b located between the storage chamber R1 and the separation chamber R2. Here, in the present embodiment, as shown in FIG. 3, the valve 40 is provided in a region of the partition portion 11b located in a horizontal plane orthogonal to the gravity direction. However, in the configuration shown in FIG. The valve 40 is provided with respect to the partition part 11b extended in the direction.

  In the configuration shown in FIG. 7, when gas is generated in the storage chamber R1 and the internal pressure of the storage chamber R1 rises, the valve 40 changes from the closed state to the open state. Then, the heat exchange medium 3 or gas existing in the storage chamber R1 moves to the separation chamber R2 via the valve 40. Then, the heat exchange medium 3 is moved below the separation chamber R2 due to the action of gravity, and the gas is moved above the separation chamber R2. Thereby, the heat exchange medium 3 and the gas can be separated in the separation chamber R2. Then, the gas that has moved above the separation chamber R <b> 2 can be discharged to the outside through the exhaust duct 44.

  Thus, even with the configuration shown in FIG. 7, the same effects as in the present embodiment can be obtained. That is, the battery pack 1 can be reduced in size in the direction of gravity and in the direction orthogonal to the direction of gravity. In the configuration shown in FIG. 7, the positional relationship between the storage chamber R1 and the separation chamber R2 can be reversed. Moreover, in the structure shown in FIG. 7, although the valve 40 is provided in the partition part 11b, the valve 40 does not need to be provided. Even in this case, by using the configuration shown in FIG. 7, the battery pack 1 can be reduced in size in the direction orthogonal to the direction of gravity (the left-right direction in FIG. 7).

  On the other hand, in the battery pack 1 of the present embodiment, when the valve 40 is in the closed state, the separation lid R2 is filled with air, and thus the bottom lid 11d does not need to have strength. For this reason, as the material for forming the bottom lid 11d, a resin having a strength lower than that of metal can be used. Thereby, cost can be reduced about the material which forms the bottom cover 11d.

  In addition, when excessive heat is applied to the battery pack 1, the unit cell 11 is excessively heated, and a large amount of gas may be generated from the unit cell 11. In this case, if the bottom lid 11d is made of resin, the bottom lid 11d can be melted by excessive heat from the outside. Thereby, the gas generated in the storage chamber R1 can be discharged not only from the exhaust duct 44 via the separation chamber R2, but also from the portion where the bottom lid 11d is disposed.

  Here, without forming the bottom lid 11d with a resin, a valve for discharging the gas moved into the storage chamber R2 to the outside of the battery pack 1 may be provided for the bottom lid 11d. Specifically, when the temperature of the battery pack 1 reaches a predetermined value or more, the valve can be changed from a closed state to an open state. Thereby, the gas generated in the storage chamber R1 can be discharged not only from the exhaust duct 44 via the separation chamber R2, but also from a valve provided on the bottom lid 11d.

  The valve provided on the bottom lid 11d may change between a closed state and an open state according to temperature, or may change between a closed state and an open state according to input of a drive signal. Also good. As the valve that changes between the closed state and the open state according to the temperature, an elastic member that can be expanded and contracted according to the temperature can be used. In addition, as a valve that changes between a closed state and an open state by the input of a drive signal, the controller determines that the temperature of the battery pack 1 detected by the temperature sensor has become a predetermined value or more, and this controller Can output a drive signal. An example of this valve is an electromagnetic valve. The valve described above does not need to be provided on the bottom lid 11d, and may be provided at any position as long as it is a wall surface constituting the separation chamber R2. That is, it is only necessary that the gas that has entered the separation chamber R2 can be discharged to the outside of the battery pack 1.

  On the other hand, the connector 33 can also be formed of resin. Since the connector 33 penetrates the partition portion 11b, if the connector 33 is also melted by excessive heat from the outside, more gas and the heat exchange medium 3 are transferred from the storage chamber R1 to the separation chamber R2. Can be moved.

  Moreover, when the internal pressure of storage chamber R1 rises too much, it can also comprise so that the connector 33 may remove | deviate from the partition part 11b. Specifically, even after the valve 40 changes from the closed state to the open state, the connector 33 can be detached from the partition portion 11b when the internal pressure in the storage chamber R1 increases.

  Here, if a structure (fixed structure) for fixing the connector 33 to the partition portion 11b is appropriately set, the connector 33 is detached from the partition portion 11b in response to the internal pressure of the storage chamber R1 reaching a specific value. be able to. Specifically, the fastening member 13 for fixing the connector 33 to the partition portion 11b can be loosened according to an increase in internal pressure in the storage chamber R1. Alternatively, the connector 33 can be detached from the partition portion 11b by deforming or cutting a fixing member for fixing the connector 33 to the partition portion 11b according to an increase in internal pressure in the storage chamber R1.

  If comprised in this way, gas and the heat exchange medium 3 can be moved to separation chamber R2 also from the part to which the connector 33 was attached.

  On the other hand, in the battery pack 1 of the present embodiment, the junction box 41 is disposed in the separation chamber R2, and the device in the junction box 41 and the battery module 20 in the storage chamber R1 are electrically connected via the connector 33. Connected. Since the connector 33 penetrates the partition portion 11b, the heat exchange medium 3 in the storage chamber R1 is prevented from moving to the separation chamber R2 by sealing the gap between the connector 33 and the partition portion 11b. .

  Here, the seal in the gap between the connector 33 and the partitioning portion 11b need only prevent the heat exchange medium 3 from leaking from the storage chamber R1 to the separation chamber R2 in a state where no gas is generated in the storage chamber R1. That is, even if the heat exchange medium 3 leaks from the gap between the connector 33 and the partitioning portion 11b due to the internal pressure of the storage chamber R1 rising due to the gas from the unit cell 21, the heat exchange medium 3 enters the separation chamber R2. It only moves and does not leak out of the battery pack 1. Therefore, the seal structure in the gap between the connector 33 and the partition portion 11b can be simplified, and the cost can be reduced.

  Further, in the battery pack 1 of the present embodiment, the battery monitoring unit 30 is disposed in the accommodation chamber R1. Here, since the battery monitoring unit 30 monitors the state of the unit cell 21, a plurality of wires corresponding to the number of the unit cells 21 are connected to the battery monitoring unit 30.

  Here, as shown in FIG. 8A, when the battery monitoring unit 30 is arranged in the separation chamber R2, a plurality of wires 201 corresponding to the number of the unit cells 21 must be provided in the connector 33, and the connector 33 Will become larger. And when the connector 33 is enlarged, the seal structure in the gap between the connector 33 and the partition portion 11b may be complicated, or the battery pack 1 may be enlarged. In FIG. 8A, the same reference numerals are used for members having the same functions as those described in this embodiment.

  On the other hand, in this embodiment, since the battery monitoring unit 30 is arranged in the accommodation room R1, as shown in FIG. 8B, a plurality of wires 201 corresponding to the number of the single cells 21 are arranged in the accommodation room R1. Will be. From the battery monitoring unit 30, only a cable 31 including two digital signal lines is drawn out. Thereby, it can suppress that the connector 33 connected with the cable 31 enlarges, and can also suppress the enlargement of the battery pack 1. FIG.

  On the other hand, in the present embodiment, an uneven surface can be formed in a portion of the lower case 11 and the upper case 12 where the accommodation chamber R1 is formed. Here, FIG. 5 shows a configuration in which the uneven portion 11 e is formed on the bottom surface of the lower case 11. In the battery pack 1 of this embodiment, as described above, the gas generated in the storage chamber R1 is moved to the separation chamber R2 positioned below the storage chamber R1. In such a configuration, it is necessary to give strength to the wall surface constituting the storage chamber R1.

  Therefore, if an uneven surface is formed on at least one of the lower case 11 and the upper case 12, the strength of the wall surface constituting the storage chamber R1 can be improved. Here, an uneven surface may be formed in a part of the lower case 11 and the upper case 12 to improve the strength. For example, since the lower case 11 and the upper case 12 are more easily deformed at the center than at the outer edge, an uneven surface can be formed at the center to improve the strength.

  The uneven surface can be provided on at least one of the inner wall surface and the outer wall surface of the lower case 11 or can be provided on at least one of the inner wall surface and the outer wall surface of the upper case 12. Here, if the inner wall surfaces of the lower case 11 and the upper case 12 are uneven surfaces, the contact area with the heat exchange medium 3 can be increased. Moreover, if the outer wall surface of the lower case 11 or the upper case 12 is an uneven surface, the contact area with the outside air can be increased. Thereby, the battery module 20 can be efficiently cooled and heated via the pack case 10.

It is a disassembled perspective view of the battery pack which is Example 1 of this invention. FIG. 3 is a top view illustrating a partial configuration inside the battery pack according to the first embodiment. It is AA sectional drawing of FIG. 1 is an exploded perspective view showing an internal configuration of a battery pack that is Embodiment 1. FIG. It is a figure when the battery pack which is Example 1 is seen from the bottom surface, Comprising: It is a figure which shows the internal structure of a separation chamber. It is a figure which shows the molded article provided with two space parts obtained by metal mold | die processing. It is a figure which shows the molded article provided with two space parts obtained by metal mold | die processing. FIG. 6 is a schematic diagram illustrating a configuration of a battery pack that is a modified example of Example 1; It is a figure which shows the wiring structure at the time of arrange | positioning a battery monitoring unit in a separation chamber. It is a figure which shows the wiring structure at the time of arrange | positioning a battery monitoring unit in a storage chamber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Battery pack (electric storage apparatus) 10: Pack case 11: Lower case 11b: Partition part 11c: Guide part 11d: Bottom cover 11e: Uneven part 12: Upper case 20: Battery module (electric storage module) 21: Single battery (electric storage) element)
3: Heat exchange medium 30: Battery monitoring unit 33: Connector 40: Valve R1: Storage chamber (first storage chamber) R2: Separation chamber (second storage chamber)

Claims (13)

A power storage module including a plurality of power storage elements;
A first storage chamber that stores the power storage module, together with a liquid heat exchange medium that performs heat exchange with the power storage element,
A second storage chamber disposed adjacent to the first storage chamber in a direction perpendicular to the direction of gravity,
One of the first and second storage chambers is composed of a recess having a shape that opens toward the upper surface of the storage chamber, and a lid member that closes the opening of the recess. The storage chamber is configured by a recess having a shape that opens toward the bottom surface of the storage chamber, and a lid member that closes the opening of the recess.   A valve is disposed between the first and second storage chambers, and has a valve that changes from a closed state to an open state and moves at least gas generated from the power storage element to the second storage chamber. The power storage device according to claim 1.   The first storage chamber includes a first region that stores the power storage module and the heat exchange medium, and a second region that is located above the second storage chamber and stores the heat exchange medium. The power storage device according to claim 2, wherein the power storage device is provided.   The power storage device according to claim 3, wherein the valve is provided in a region of the second storage chamber that faces the upper surface of the first storage chamber.   The power storage device according to claim 4, further comprising a guide portion that extends upward with respect to the valve and forms a passage through which the heat exchange medium and the gas move to the second storage chamber.   6. The power storage device according to claim 1, wherein the first storage chamber has an uneven portion on at least one of an inner wall surface and an outer wall surface.   The part located in the outer surface of the said electrical storage apparatus among the said 2nd storage chamber is formed with resin, The electrical storage apparatus as described in any one of Claim 2 to 6 characterized by the above-mentioned.   The power storage according to any one of claims 2 to 6, wherein the second storage chamber has a valve for discharging the gas moved from the first storage chamber to the outside of the power storage device. apparatus.   The valve causes the gas to be discharged from the second storage chamber to the outside of the power storage device by changing from a closed state to an open state when the temperature of the power storage device becomes a predetermined value or more. The power storage device according to claim 8, which is characterized by:   The connector is disposed between the first and second storage chambers, and has a connector for electrically connecting the power storage module and a device stored in the second storage chamber. The power storage device according to any one of 1 to 9. Having a fixing structure for fixing the connector to the first or second accommodation chamber;
The power storage device according to claim 10, wherein the fixing structure releases the fixing of the connector in response to an increase in internal pressure of the first storage chamber due to generation of the gas.   The power storage device according to claim 10 or 11, wherein the connector is formed of a resin. The power storage device according to any one of claims 1 to 12, wherein the power storage module includes a monitoring unit for monitoring a state of the power storage element.

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