JP2011243524A - Battery pack module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack module in which deterioration of battery performance and shortening of life span can be prevented by keeping the temperature of the battery at an appropriately level over a wide environmental temperature range.SOLUTION: A plurality of flat unit cells 3 are arranged while being stacked so that long side faces of adjoining unit cells 3 face each other. Furthermore, carbon plates 7 are arranged along one long side face of the unit cell 3, and film heaters 5 are arranged along the other long side face. The carbon plate 7 and film heater 5 are arranged to be stacked alternately while having the unit cell 3 sandwiched between them. The film heater 5 is connected to a heater controller. When temperature of the unit cell 3 drops to 0°C or lower, the heater controller controls the film heater 5 to be heated. When temperature of the unit cell 3 rises to 0°C or higher, heating is stopped by the heater controller. Heat of the unit cell 3 is transmitted to the carbon plate 7 and released from a protrusion of the carbon plate 7 into the air.

Description

  The present invention relates to an assembled battery module.

  Conventionally, in order to cope with a variety of load voltages and load capacities with a common battery, the battery is often connected in series, in parallel, or a combination thereof to form an assembled battery. As a battery assembly method, a plurality of batteries are generally fixed with a tape, fixed with a heat shrinkable tube, or stored in a hard case. However, in these general assembled battery construction methods, heat due to heat generation of the battery itself is not released and accumulated, and the battery becomes high temperature, resulting in a short life. In particular, in recent years, applications used for rapid charging and high rate discharge have increased, and the battery temperature tends to be high, which is a cause of further shortening the life.

  In particular, when the assembled battery is configured so that the long side surfaces of the flat battery are in contact with each other, there is almost no heat dissipation path other than the tab lead. Therefore, the temperature of the battery located in the central portion where both long side surfaces are in contact with the battery becomes very high, and the life of the battery is reached earlier than that of other batteries, and the life of the assembled battery is shortened.

  When using an assembled battery in an environment of room temperature or higher, as a measure to lower the battery temperature, (1) an air cooling method is proposed in which a gap is formed between the cells and cooling is performed by flowing cooling air therethrough. Yes. In addition, (2) a water cooling method in which a coolant is circulated between single cells has been proposed. Furthermore, when used in an environment where the temperature changes drastically from low temperature to high temperature, (3) a heater is provided on the upper side of each flat battery, and a heat conductive sheet is provided on the lower side of the same side. Has been proposed, and heat is dissipated to the mounting panel via a heat conductive sheet at high temperatures (see, for example, Patent Document 1).

Japanese Utility Model Publication No. 2-128368

  However, in the air cooling method (1) and the water cooling method (2), a gap for circulating the cooling air or the cooling liquid between the single cells is necessary, and the battery module becomes larger accordingly. In addition, when these types of assembled battery modules are used for mobile bodies that are constantly subject to large impacts such as electric cars and aircraft, the vibration-resistant design becomes complicated due to the gaps between the single cells, which is sufficient. It is difficult to obtain a strong vibration-proof structure.

  Further, in the method of (3) proposed to be used in a wide temperature environment from low temperature to high temperature, a sheet-like heater is disposed on the upper part of the storage battery mating surface, and a high thermal conductive sheet is disposed on the side surface and the lower surface. Since these are not in contact with each other (see FIG. 3 in Patent Document 1), it takes time to heat the entire storage battery at a low temperature, and the sheet heater is disposed between the stacked storage batteries, so that the cost is low. There is a problem that it takes.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an assembled battery that can prevent deterioration in battery performance and shortening of service life by maintaining the battery at an appropriate temperature in a wide environmental temperature range. Is to provide modules.

  In order to achieve the above-described object, the present invention is arranged along a plurality of flat unit cells that are stacked so that the long side faces each other and one long side of one unit cell. A heat conductive plate and a heater disposed along the other long side surface of the one unit cell, and the heat conductive plate and the heater are alternately stacked with the unit cell interposed therebetween. It is the assembled battery module characterized by the above-mentioned.

  By adopting such a configuration, a heat conductive plate is alternately arranged on one long side of the unit cell and a heater is alternately arranged on the other long side, so that the heat conductive plate and the heater are not arranged between the unit cells. In addition to being able to heat and cool a single cell, heat radiation with a heat conductive plate and heating with a heater enable a wide range of environmental temperatures from low temperatures below 0 ° C to high temperatures above normal. The battery can be kept at an appropriate temperature in the range.

  The thermally conductive plate is a carbon plate, a metal plate, carbon powder, or a buffer plate obtained by solidifying metal powder or diamond powder with resin or rubber. They have sufficient thermal conductivity and are suitable for such purposes. In particular, since the specific gravity of the carbon plate is small, the weight can be further reduced.

  When a carbon plate is used as the thermally conductive plate, it is preferable that the thermal conductivity in the thickness direction is lower than the thermal conductivity in at least one plane. Since the carbon plate has a different thermal conductivity depending on the crystal arrangement direction, the thermal conductivity in the thickness direction can be made extremely lower than that in the plane direction by stacking the crystals in the thickness direction. By using such a carbon plate, the heat conducted to the adjacent unit cells can be reduced and the heat can be efficiently radiated.

  Moreover, when using a carbon plate as a heat conductive plate, a metal foil is bonded to the surface of the carbon plate as necessary. By bonding metal foil with high thermal conductivity such as aluminum foil or copper foil to the surface of the carbon plate, the brittleness against vibration and impact is compensated while taking advantage of the good characteristics of the carbon plate that is lightweight. Durability can be improved.

  It is desirable to arrange the heat conductive plate so as to protrude from the short side surface of the unit cell. By projecting the thermally conductive plate, heat can be released from the thermally conductive plate itself into the air, which makes it possible to reduce the weight and cost as compared to a battery pack using a conventional heat sink or the like. . Moreover, heat dissipation performance can be increased by flowing air through the protruding portion of the heat conductive plate.

  The heater is preferably a film heater. By using a film heater, the thickness of the assembled battery can be reduced. Moreover, the assembled battery module of 1st invention is further equipped with the temperature sensor which detects the battery temperature of a cell, and a heater is heated or stopped by the battery temperature detected with the temperature sensor. Thereby, the battery temperature is controlled according to the temperature of the unit cell.

  According to the present invention, the heat conductive plate and the heater are not disposed between the single cells by alternately disposing the heat conductive plate on one long side of the unit cell and the heater on the other long side. In addition, it is possible to provide an assembled battery module capable of heating and cooling a single cell and preventing battery performance deterioration and shortening of service life by maintaining the battery at an appropriate temperature in a wide environmental temperature range. .

The perspective view of the assembled battery module 1 Vertical sectional view of the battery module 1 Assembly drawing of assembled battery module 1 The figure which shows the connection state of the film heater 5 Side view of the assembled battery module 1a

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of the assembled battery module 1. FIG. 2 is a vertical cross-sectional view of the assembled battery module 1. FIG. 2 is a cross-sectional view of the assembled battery module 1 cut in the vertical direction so as to cross the carbon plate 7 and the film heater 5. FIG. 3 shows an assembly drawing of the assembled battery module 1.

  As shown in FIGS. 1 to 3, the assembled battery module 1 includes a plurality of flat unit cells 3 (3-1, 3-2, 3-3,..., 3- (n-2), 3- ( n-1), 3-n), a carbon plate 7 as a heat conductive plate, a film heater 5 as a heater, a low-hardness heat conductive sheet 17, a pressing plate 11, a pressing plate 13, a fixing screw 15, and the like.

  The unit cells 3 (3-1, 3-2, 3-3,..., 3- (n-2), 3- (n-1), 3-n) are long side surfaces 21 of the adjacent unit cells 3. Are arranged so as to face each other. The unit cell 3 has a terminal 9 a and a terminal 9 b on the end surface 19. One of the terminals 9a and 9b is a positive terminal and the other is a negative terminal. The plurality of single cells 3 are arranged such that the terminals 9a and 9b are located on the same side of the assembled battery module 1.

The carbon plate 7 is disposed along one long side surface 21 of the unit cell 3. The film heater 5 is disposed along the other long side surface 21 of the unit cell 3. As shown in FIG. 2, in the assembled battery module 1, the carbon plate 7, the unit cell 3-1, the film heater 5, the unit cell 3-2, the carbon plate 7, the unit cell 3-3. And the film heater 5 are alternately stacked and disposed between adjacent unit cells 3 so as to sandwich the unit cell 3 therebetween.
The carbon plates 7 and the film heaters 5 are alternately stacked with the single cells 3 interposed therebetween, so that it is not necessary to arrange the carbon plates 7 and the film heaters 5 between the single cells. In addition, an assembled battery can be manufactured at low cost.

Since the carbon plate 7 is formed by stacking crystals in the thickness direction, the thermal conductivity in the width direction of the carbon plate 7 (for example, the height direction shown in the vertical direction in FIGS. 1 and 3) is increased (for example, 200). ~500Wh / cm ² or so), the thermal conductivity in the thickness direction very low compared with the width direction (e.g., 10 Wh / cm ² of about or less) it is desirable to. The carbon plate 7 is disposed so that the protruding portion 35 protrudes from the upper surface 23 which is the short side surface of the unit cell 3.
In the present application, an example in which the carbon plate 7 that is a heat conductive plate is arranged so as to protrude from the upper surface 23 is shown. However, the protruding portion is not limited to the upper surface 23, and may include the left and right short side surfaces. It is possible to further increase the heat dissipation performance of the unit cell by increasing the area of the protruding portion.

  The low hardness heat conductive sheet 17 is disposed on both surfaces of the carbon plate 7. The low hardness heat conductive sheet 17 is double-sided adhesive. By disposing the low-hardness heat conductive sheet 17 between the carbon plate 7 and the unit cell 3 or the like, they are fixed so as to be in close contact with each other.

  The pressing plate 11 is disposed along the long side surface 21 of the unit cell 3, one on each end of the assembled battery module 1. The pressing plate 13 is disposed along the end surface 19 of the unit cell 3 so as to connect the two pressing plates 11 together. The holding plate 11 has a screw hole 25. The holding plate 13 has a screw hole 27 at a position overlapping the screw hole 25 of the holding plate 11. The holding plate 11 and the holding plate 13 are integrated by screwing the fixing screw 15 into the screw hole 25 and the screw hole 27 that are overlapped. The integrated presser plate 11 and presser plate 13 fix and hold the unit cell 3, the carbon plate 7, the film heater 5, and the like.

  FIG. 4 is a diagram schematically showing a connected state of the film heater 5 in a plane. In FIG. 4, illustration of the low-hardness heat conductive sheet 17 is omitted. As shown in FIG. 4, the plurality of film heaters 5 are connected in series by a heater power cable 29. The plurality of film heaters 5 are connected to a heater controller 33 via a heater power cable 29 and receive power supply from a power source (not shown) via the heater controller 33 and the like. As the power source, a battery, a commercial power source, or the like can be used. The heater controller 33 is connected to a temperature sensor 31 disposed on the surface of the unit cell 3 near the center.

  Next, the operation of the assembled battery module 1 will be described. In the assembled battery module 1, the temperature sensor 31 shown in FIG. 4 detects the temperature of the cell 3 near the center. In the assembled battery module 1, when the battery temperature becomes 0 ° C. or less, the heater controller 33 heats the film heater 5. On the other hand, when the battery temperature becomes 0 ° C. or higher, heating of the film heater 5 by the heater controller 33 is stopped. Even when the film heater 5 is heated by the heating of the film heater 5 and the heating of the film heater 5 is stopped when it exceeds 0 ° C., the battery itself generates heat and the battery temperature rises. Chattering such as repeated stops will not occur.

  Further, the heat of the unit cell 3 is transmitted to the carbon plate 7 and is released into the air from the protruding portion 35 of the carbon plate 7. At this time, the heat radiation performance can be further increased by flowing air around the protrusion 35 of the carbon plate 7 using a blower mechanism (not shown).

  Thus, in the present embodiment, the carbon plate 7 that is a heat conduction plate is provided along one long side surface 21 of the flat unit cell 3, and the film heater 5 that is a heater is provided along the other long side surface 21. The assembled battery module 1 is arranged in the order of the carbon plate 7, the unit cell 3, and the film heater 5. And when battery temperature is 0 degrees C or less, it controls so that the film heater 5 may be heated. In the assembled battery module 1, the unit cell 3 is heated by the film heater 5 at 0 ° C. or lower, and the heating is stopped at 0 ° C. or higher. Further, in the assembled battery module 1, heat is released from the single battery 3 into the air via the carbon plate 7. Thereby, it is possible to heat and cool the unit cell 3 without arranging a heat conductive plate and a heater between each unit cell, and from a low temperature environment of 0 ° C. or lower to a high temperature environment of normal temperature or higher, It is possible to keep the unit cell 3 at an appropriate temperature in a wide environmental temperature range and prevent the unit cell 3 from being deteriorated in performance or shortening its life.

  In the assembled battery module 1, the carbon plate 7 is used together with the low-hardness heat conductive sheet 17 and disposed between the flat unit cells 3, so that the thermal resistance due to slight unevenness on the surface of the unit cell 3 is reduced. Thus, heat dissipation is improved. Further, by using the double-sided adhesive low-hardness heat conductive sheet 17, the adhesion between the carbon plate 7 and the unit cell 3 and the like is improved, and the vibration resistance is improved. The same effect can be obtained when a heat conductive adhesive is used instead of the low hardness heat conductive sheet 17.

  In the battery module 1, the crystals are stacked in the thickness direction, whereby the thermal conductivity in the width direction of the carbon plate 7 is increased, and the thermal conductivity in the thickness direction is decreased as compared with the width direction. Thus, by reducing the thermal conductivity in the thickness direction from at least the thermal conductivity in one direction of the plane, the heat conducted to the adjacent unit cells 3 can be reduced and the heat can be efficiently radiated.

  In the assembled battery module 1, a carbon plate 7 having a small specific gravity is used as a heat conductive plate, and a film heater 5 that can reduce the thickness of the assembled battery module is used as a heater. Thereby, weight reduction and size reduction are attained.

  In the assembled battery module 1, the carbon plate 7, which is a heat conductive plate, is protruded from the upper surface 23 of the unit cell 3 to release heat from the carbon plate 7 itself into the air. Therefore, the weight can be reduced and the cost can be reduced as compared with a method in which a heat conductive plate is closely attached to a heat sink or the like and heat is released from the heat sink or the like into the air.

  The carbon plate 7 may be bonded to a metal foil (not shown) having a high thermal conductivity such as an aluminum foil or a copper foil on the surface. Thereby, the vibration resistance and impact resistance of the carbon plate 7 are improved, and higher mechanical durability can be obtained without impairing the good characteristics of the carbon plate 7 that it is lightweight.

  In the assembled battery module 1 of the present embodiment, the carbon plate 7 is used as the heat conductive plate. However, the heat conductive plate has sufficient heat conductivity and generates heat generated by the flat unit cell 3. Any material that can conduct heat to dissipate heat may be used. For example, metal (aluminum, copper, stainless steel, steel, iron-nickel plating, magnesium), carbon powder, buffer plate in which metal powder or diamond powder is hardened with resin or rubber, synthetic resin (polyolefin such as polyethylene and polypropylene) Resin, high melting point resin such as polyethylene terephthalate, polytetrafluoroethylene, and polyamide resin), heat conductive plastic, silicon rubber sheet, ethylene propylene rubber sheet (EPT), butyl rubber sheet, and the like. On the other hand, the use of the carbon plate 7 as in the present embodiment makes it possible to further reduce the weight of the assembled battery module 1 with a small specific gravity, and to make the thermal conductivity different depending on the crystal arrangement direction. There is an advantage that the unit cell 3 can be efficiently radiated without heating.

  In the assembled battery module 1, the film heater 5 is used as a heater. However, the heater may be anything that can heat the flat unit cell 3. However, in order not to increase the size of the assembled battery, it is preferable to use a film heater.

  Furthermore, in the assembled battery module 1, the carbon plate 7 which is a heat conductive plate is sandwiched between the low hardness heat conductive sheets 17, but the low hardness heat conductive sheet 17 is not an essential constituent member. The low-hardness heat conductive sheet 17 is installed as necessary.

  In the assembled battery module 1 of the present embodiment, the carbon plate 7 is protruded from the upper surface 23 of the unit cell 3, but the protrusion 35 is not provided and may be flush with the upper surface 23 of the unit cell 3, a heat sink, etc. The heat dissipation plate may be disposed between the single cells 3.

  FIG. 5 shows a side view of an assembled battery module 1a in which a heat sink is provided in the assembled battery module 1 of the present embodiment. As shown in FIG. 5, in the assembled battery module 1a, the vicinity of the end portion 37 of the protruding portion 35a of the carbon plate 7a is bent in an L shape, and the heat sink 39 is installed on the upper portion of the protruding portion 35a. Thereby, the discharge | release of the heat | fever which generate | occur | produced in the cell 3 can further be accelerated | stimulated.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

DESCRIPTION OF SYMBOLS 1, 1a ......... Battery module 3 ......... Single cell 5 ......... Film heater 7, 7a ......... Carbon plate 17 ......... Low-hardness heat conductive sheet 21 ......... Long side 23 ......... Top 29 ......... Heater power cable 31 ......... Temperature sensor 33 ......... Heater controller 35, 35a ......... Protrusions

Claims (8)

A plurality of flat cells arranged in a stacked manner so that the long sides face each other;
A thermally conductive plate disposed along one long side of one unit cell;
A heater disposed along the other long side of the one unit cell;
An assembled battery module, wherein the thermally conductive plate and the heater are alternately stacked with the unit cell interposed therebetween.   The assembled battery module according to claim 1, wherein the thermally conductive plate is a carbon plate.   The assembled battery module according to claim 1, wherein the heat conductive plate is a metal plate.   The assembled battery module according to claim 2, wherein the carbon plate has a thermal conductivity in a thickness direction lower than a thermal conductivity in at least one plane.   3. The assembled battery module according to claim 2, wherein a metal foil is bonded to the surface of the carbon plate.   The assembled battery module according to claim 1, wherein the heat conductive plate is disposed so as to protrude from a short side surface of the unit cell.   The assembled battery module according to any one of claims 1 to 6, wherein the heater is a film heater. A temperature sensor for detecting a battery temperature of the unit cell;
The assembled battery module according to any one of claims 1 to 7, wherein the heater is heated or stopped by a battery temperature detected by the temperature sensor.

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