JP2008097830A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack capable of cooling a battery nearly uniformly by improving cooling efficiency of the battery in the downstream region and capable of preventing reduction of a battery life. <P>SOLUTION: This is the battery pack 10 in which a power generating element wherein a positive electrode plate and a negative electrode plate are laminated is sealed inside the outer layer member, in which an electrode terminal connected to the power generating element is led out to the outside of the outer layer member, and in which a plurality of a flat type battery of outer shape flat type are laminated. At every prescribed sheet of the flat type battery, this is equipped with a gap as a cooling wind flow passage 51 into which the cooling wind flows, and a straightening plate 30 to split the gap toward the battery inside 53b of the center side of the cooling wind flow passage width direction in the upstream region of the cooling wind circulating direction and toward the battery side 52a of more outside of the cooling wind flow passage width direction than the battery inside, and to guide the cooling wind which is circulating through the battery side at the downstream region in the cooling wind circulating direction toward the battery inside. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an assembled battery in which an arbitrary number of batteries are connected in series and / or in parallel.

  A flat battery (hereinafter referred to as “battery”) in which a power generation element is sealed in a sheet-shaped exterior member and a plate-like electrode tab (electrode terminal) connected to the power generation element is led out of the exterior member. A battery module formed by laminating a plurality of layers is known (for example, see Patent Document 1). It is generally performed to form a battery pack with high output and high capacity by arranging a plurality of such battery modules and electrically connecting each battery module in series and / or in parallel (for example, Patent Document 2). The battery module is a battery in the sense of a unit unit for assembling an assembled battery, and is a kind of assembled battery because it includes a plurality of electrically connected flat batteries.

In such an assembled battery, the temperature of the assembled battery rises due to the heat generated by the battery during charging and discharging, and the life of the battery is reduced. Therefore, in assembling the assembled battery, the batteries are cooled by arranging the batteries (or between the battery modules) with a gap therebetween and flowing cooling air through the cooling air passage formed by the gap.
JP 2001-256934 A JP-A-2005-302698

  By the way, in the conventional assembled battery, it is possible to efficiently cool the battery in the upstream area of the cooling air flow path, but the cooling air warmed through the upstream area is supplied to the downstream area as it is. The cooling efficiency of the becomes worse. As a result, the battery cannot be cooled uniformly, and the battery life may be reduced.

  The present invention was devised in view of the above circumstances, and can improve the cooling efficiency of the battery in the downstream region to cool the battery substantially uniformly, and can prevent the battery life from being lowered. An object is to provide a battery.

  In order to achieve the above object, an assembled battery according to the present invention seals a power generation element in which a positive electrode plate and a negative electrode plate are laminated inside an outer layer member, and has an electrode terminal connected to the power generation element outside the outer layer member. A battery pack that is formed by laminating a plurality of flat-type batteries having a flat outer shape, and for each predetermined number of the flat-type batteries, a gap as a cooling air flow channel into which cooling air flows and the gap is cooled. In the upstream area of the wind flow direction, the battery is divided into the inner side of the battery in the width direction of the cooling air flow path and the battery side of the outside of the battery in the width direction of the cooling air flow path. And a rectifying plate for guiding the cooling air flowing through the battery toward the inside of the battery.

  According to the assembled battery according to the present invention, by providing the rectifying plate in the cooling air flow path, the cooling air that has passed through the side of the battery in the upstream area of the cooling air flow path and has not risen in temperature is in the battery in the downstream area. Therefore, it is possible to improve the cooling efficiency of the battery in the downstream region, cool the battery substantially uniformly, and prevent the battery life from decreasing.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1A is a perspective view showing an example of an assembled battery 10 according to the present embodiment as seen from the front side, and FIG. 1B is a perspective view showing the assembled battery 10 as seen from the back side. FIG. 2 is a perspective view showing the assembled battery 10 after arranging the battery modules 50 and before connecting the bus bars. FIG. 3 is a schematic diagram showing an arrangement state of the battery modules 50. FIG. 4 is a perspective view showing an example of a battery module 50 that is a unit unit when the assembled battery 10 is assembled. FIG. 5 is a perspective view showing the battery module 50 shown in FIG. FIG. 6 is a perspective view showing an example of the flat battery 100. FIG. 7 is a plan view showing a state in which the rectifying plate 30 of the first example is disposed in the cooling air passage 51. FIG. 8 is a plan view showing a state in which the rectifying plate 30 of the second example is disposed in the cooling air passage 51. FIG. 9 is a perspective view showing a state in which the current plate 30 of the second example is disposed on the battery module 50. FIG. 10 is a perspective view showing the current plate 30 of the second example. FIG. 11 is a plan view showing a state in which the rectifying plate 30 of the third example is disposed in the cooling air flow path 51. FIG. 12 is an explanatory diagram showing temperature variations of the conventional battery module 50. The X-axis direction shown in FIG. 4 is referred to as the longitudinal direction of the battery module 50, and the Y-axis direction is referred to as the short direction. In FIG. 2, the surface on which the output terminals 140 and 150 are located is the front surface, and the opposite surface opposite to the front surface is the back surface.

  With reference to FIG. 1 and FIG. 2, the assembled battery 10 of the present embodiment is an in-vehicle battery mounted on a vehicle such as an automobile or a train, and a plurality of battery modules 50 are provided in the assembled battery case 11. They are arranged with a gap. The assembled battery case 11 includes an upper case 12 and a lower case 13. An inlet duct 14 for introducing cooling air is connected to the front surface of the upper case 12, and the cooling air is led to the back surface of the upper case 12. The outlet duct 15 is connected. The inlet duct 14 is connected to the blower, and the cooling air supplied from the blower is guided into the assembled battery case 11 through the inlet duct 14.

  By connecting any number of battery modules 50 in series and parallel, the assembled battery 10 can handle a desired current, voltage, and capacity. In FIG. 2, the assembled battery 10 includes, for example, 12 battery modules 50. The twelve battery modules 50 have a group of three battery modules 50a stacked in the vertical direction and arranged in four rows in the horizontal direction. The positive and negative output terminals 140 and 150 of the battery module 50 are all provided on the same surface (front surface).

  The battery modules 50 are air-cooled, and a gap between the battery modules 50 is used as a cooling air flow path 51 through which cooling air for cooling each battery module 50 flows. The cooling air flows in the cooling air flow channel 51 from the front side where the positive and negative output terminals 140 and 150 of the battery module 50 are provided to the back side. By cooling each battery module 50 by flowing cooling air, the battery temperature is lowered and the characteristics such as charging efficiency are prevented from being lowered. The gap S between the upper and lower battery modules 50, that is, the height of the cooling air flow path 51 is defined by the height of the spacers 20 arranged between the battery modules 50 during stacking. The spacer 20 is, for example, a cylindrical washer, and is bolted to a bolt hole 73 described later (see FIGS. 4 and 5). The gap S defined by the spacer 20 is determined in consideration of a layout when mounted on the vehicle, dimensions necessary for functioning as the cooling air flow path 51, and the like, but is about several mm.

  With reference to FIGS. 3 and 7 to 11, in the assembled battery 10 of the present embodiment, a rectifying plate 30 that controls the direction of the cooling air is disposed in the gap S between the battery modules 50 serving as the cooling air flow path 51. The rectifying plate 30 is formed so as to guide the cooling air that has passed through the battery side 52 a in the upstream region 52 of the cooling air flow channel 51 to the battery inner 53 b in the downstream region 53. In the present invention, the upstream region 52 of the cooling air flow channel 51 refers to a region in the first half of the longitudinal length of the battery (battery module 50), and the downstream region 53 refers to the longitudinal length of the battery (battery module 50). This is the area in the latter half.

  The rectifying plate 30 of the first example shown in FIG. 7 divides the cooling air by dividing the upstream area 52 of the cooling air passage 51 into the battery side 52a on the outer side and the battery inner side 52b on the center side in the width direction of the cooling air passage. The separation plate 31 that performs (separates) and the guide plate 32 that joins the cooling air that has passed through the battery side 52 a in the upstream region 52 to the battery inner 53 b in the downstream region 53. The separation plate 31 is disposed on both sides in the left-right direction on the battery module 50 in the upstream region 52 of the cooling air flow channel 51. The separation plate 31 is a straight plate having the same height as the spacer 20, and stands up along the longitudinal direction of the battery module 50. Further, the guide plate 32 obliquely crosses the battery side 53a in the downstream region 53 in the vicinity of the boundary between the upstream region 52 and the downstream region 53 of the cooling air flow channel 51, with a space from the separation plate 31. The wind direction is changed. The guide plate 32 is a straight plate having the same height as the spacer 20, and is located in the longitudinal direction rearward of the battery module 50 from the vicinity of the boundary between the upstream region 52 and the downstream region 53 of the cooling air flow channel 51. It stands up obliquely toward the central portion (the central portion of the battery inner side 53b in the downstream region 53). An interrupted portion of the plate between the separation plate 31 and the guide plate 32 is an introduction flow path 51a that joins the cooling air that has passed through the battery side 52a in the upstream region 52 to the battery inner 53b in the downstream region 53. It becomes.

  According to the rectifying plate 30 of the first example shown in FIG. 7, the cooling air in the upstream region 52 is separated into the flow of the battery side 52 a and the flow of the battery inner 52 b by the separation plate 31, and the upstream region is separated by the guide plate 32. By changing the direction of the cooling air that has passed through the battery side 52a of the battery 52 and has not increased in temperature, and merged with the battery inner side 53b of the downstream region 53, the cooling air temperature in the downstream region 53 is lowered and the cooling efficiency is reduced. Has improved. Since the cooling efficiency of the downstream area 53 is improved, the temperature variation of the battery interiors 52b and 53b can be reduced to cool the battery modules 50 substantially uniformly, and the lifetime of each battery module 50 can be prevented from being reduced. . In the present invention, as will be described later, the flat battery 100 is housed in the module case 70 to form the battery module 50. In such a flat battery 100, when heat is generated with charging / discharging, the temperature generally increases from the outside of the battery (as viewed from the battery thickness direction) toward the center of the battery. Therefore, when cooling air is made to flow on the surface of the battery module 50 using such a flat battery, the temperature of the cooling air passing through the battery inner side 52b (center direction in the cooling air flow path width direction) is high, The temperature of the cooling air that has passed through the battery side 53b (the outer side in the cooling air flow path width direction) is lower than the temperature of the cooling air that has passed through the battery inner side 52b. In the present embodiment, as described above, the cooling air that has passed through the battery side 53b in the upstream region of the cooling air flow direction and the cooling air that has passed through the battery inner side 52b are merged in the downstream region of the cooling air flow direction. The temperature difference between the temperature of the cooling air flowing in the upstream area in the cooling air flow direction and the temperature of the cooling air flowing in the lower area in the cooling air flow direction is reduced, and the battery module 50 can be cooled as uniformly as possible.

  The separation plate 31 and the guide plate 32 can be made of, for example, a metal plate such as a thin steel plate or an aluminum plate made of the same material as the module case 70 described later. Also works.

  In the rectifying plate 30 of the second example shown in FIGS. 8 and 9, a curved separation plate 33 that separates the upstream region 52 of the cooling air flow passage 51 into the battery side 52 a and the battery inner 52 b, and the battery side in the upstream region 52. And a curved guide plate 34 that joins the cooling air that has passed through the direction 52 a to the battery inner side 53 b in the downstream region 53. The separation plate 33 and the guide plate 34 have the same height as the spacer 20 and are preferably formed integrally with the spacer 20 that forms the gap S between the battery modules 50 as described later. . The separation plate 33 is disposed along the longitudinal direction of the battery module 50 on both sides in the left-right direction on the battery module 50 in the upstream region 52 of the cooling air flow channel 51, and the extending end 33 a side of the separation plate 33 is the side of the battery module 50. Stands up to curve inward. In addition, the guide plate 34 bends and crosses the battery side 53a in the downstream region 53 at an angle in the vicinity of the boundary between the upstream region 52 and the downstream region 53 of the cooling air flow channel 51 with a space from the separation plate 33. And is gradually bent inward of the battery module 50 from the proximal end portion 34a in the vicinity of the boundary between the upstream region 52 and the downstream region 53 of the cooling air passage 51 toward the rearward extending end side. Stand up like you do. A space defined by the extended end 33 a side of the curved separation plate 33 and the proximal end side 34 a of the curved guide plate 34 is used to cool the cooling air that has passed through the battery side 52 a of the upstream region 52 in the downstream region 53. In this case, the introduction flow path 51a is joined to the battery inner side 53b.

  FIG. 10A shows an example in which the spacer 20 and the curved separation plate 33 or the curved guide plate 34 are formed separately. FIG. 10B is an example in which the spacer 20 and the curved separation plate 33 or the curved guide plate 34 are integrally formed, and one end of the plate material is contacted and fixed to one side of the circumferential portion of the spacer 20. For example, it corresponds to the structure of the guide plate 34 in FIGS. In FIG. 10C, the spacer 20 and the curved separation plate 33 or the curved guide plate 34 are integrally formed, and the bifurcated ends of the Y-shaped plate material are contact-fixed on both sides in the radial direction of the circumferential portion of the spacer 20. This is an example. For example, it corresponds to the structure of the separation plate 33 in FIGS.

  According to the rectifying plate 30 of the second example shown in FIGS. 8 and 9, since the separation plate 33 and the guide plate 34 are curved plates, the extension end 33 a side of the separation plate 33 and the base end portion 34 a of the guide plate 34. The cooling air that has passed through the battery side 52a in the upstream region 52 and has not risen in temperature can be smoothly introduced into the battery inner side 53b in the downstream region 53 through the introduction flow path 51a partitioned into the first and second regions. In particular, by integrally forming the current plate 30 (the curved separation plate 33 and the curved guide plate 34) and the spacer 20 for adjusting the gap, there is no need to add the number of parts or a new structure for fixing the current plate. The rectifying plate 30 can be added without increasing the cost and without increasing the number of assembling steps of the rectifying plate 30.

  In the third example shown in FIG. 11, a rectifying plate 30A is arranged in an S shape from the front left spacer 20a toward the rear right spacer 20d, and the battery adjacent to the right side from the front right spacer 20b. A rectifying plate 30B is disposed so as to be curved in an S shape toward the spacer 20c on the left rear side of the module 50. Symmetrically symmetrical with this configuration, a rectifying plate 30A is provided by being curved in an S shape from the front right spacer 20b toward the rear left spacer 20c, and the battery module adjacent to the left side from the front left spacer 20a. The rectifying plate 30B may be arranged so as to be curved in an S shape toward the spacer 20d on the right rear side of the 50. That is, the rectifying plate 30A is disposed on the battery module 50, and the rectifying plate 30B is disposed so as to straddle between the left and right adjacent battery modules 50. In this case, the left and right adjacent battery modules are arranged. The space between 50 is wider than the first example and the second example. Both ends of each rectifying plate 30 are preferably formed integrally with the spacer 20 for adjusting the gap.

  According to the rectifying plate 30 of the third example shown in FIG. 11, the cooling air that has passed through the battery inner side 52b in the upstream region 52 of the cooling air flow passage 51 and has risen in temperature flows into the curved rectifying plate 30A and the rectifying plate 30B. Guided by the partitioned space, it is escaped to the battery side 53a in the downstream area 53. On the other hand, the cooling air that has not passed through the battery side 52a in the upstream region 52 of the cooling air flow channel 51 and has not risen in temperature is introduced into the space defined by the curved rectifying plate 30B and the rectifying plate 30A, and the downstream region The battery 53 is guided to the battery inner side 53b.

  Referring to FIG. 12, in the conventional assembled battery, since only the spacer 20 is provided in the gap S between the upper and lower battery modules 50 that become the cooling air flow channel 51, the battery inner side 52 b in the upstream region 52 of the cooling air flow channel 51. Since the cooling air that has passed through and has risen in temperature flows to the battery inner side 53b in the downstream region 53 as it is, the temperature further rises in the downstream region 53 of the battery module 50 to a higher temperature, and reaches the temperature of the battery interiors 52b and 53b. Variation occurs.

  On the other hand, according to the rectifying plate 30 of the first to third examples, by arranging the rectifying plate 30 in the gap S between the battery modules 50 serving as the cooling air flow channel 51, the upstream region 52 of the cooling air flow channel 51. In the downstream area 53, the low-temperature cooling air that has passed through the battery side 52a and has not increased in temperature can be actively guided to the battery inner side 53b, and the cooling air temperature in the downstream area 53 is lowered to increase the temperature. It is possible to improve cooling efficiency. Therefore, the temperature variation of the battery interiors 52b and 53b can be reduced, the battery module 50 can be cooled substantially uniformly, and the lifetime of each battery module 50 can be prevented from being reduced.

  4 and 5, the battery module 50 forms a unit unit for assembling the assembled battery 10, and is electrically connected to a plurality of (eight in the illustrated example) flat batteries 100 (of 101 to 108). The cell unit 60 including the generic name) is housed in the module case 70. The battery module 50 is a kind of assembled battery in that it includes a plurality of electrically connected flat batteries (unit cells). In this specification, the unit unit for assembling the “assembled battery” In this respect, the battery according to the present invention is also referred to as a “battery module”. The unit includes a plurality of single cells housed in a module case.

  The module case 70 includes a first case 71 having a box shape in which an opening 71a is formed, and a second case 72 forming a lid for closing the opening 71a. The edge 72a of the second case 72 is wound around the edge 71c of the peripheral wall 71b of the first case 71 by caulking (see the partially enlarged view of FIG. 4). The first case 71 and the second case 72 are formed from a relatively thin steel plate or aluminum plate, and are given a predetermined shape by press working.

  The cell unit 60 includes a cell unit main body 80 in which eight flat batteries 100 are stacked and the flat batteries 100 are connected in series, and an insulating cover that is detachably attached to the front and back surfaces of the cell unit main body 80. 91, 92. In the cell unit main body 80, each electrode tab 100t is sandwiched by a plurality of spacers 110, and positive and negative output terminals 140 and 150 are connected.

  The insulating covers 91 and 92 are used to cover the front side and the back side of the cell unit main body 80. An insertion port 91 a into which a connector (not shown) is inserted is formed at the center position of the insulating covers 91 and 92. The detection of voltage is performed for charge / discharge management of the battery module 50.

  The positive and negative output terminals 140 and 150 are led out from the module case 70 through notches 71d and 71e formed in a part of the peripheral wall 71b of the first case 71. The insertion port 91a of the insulating covers 91 and 92 is also exposed to the outside of the module case 70 through a notch 71f formed in a part of the peripheral wall 71b. Screw holes 141 and 151 into which bolts (not shown) are screwed are formed on the front surfaces of the output terminals 140 and 150.

  In order to insert through-bolts (not shown) in the four corners of the module case 70, bolt holes 73 are formed in the four corners of the first case 71 and the second case 72, and Bolt holes 111 are formed in two places. 4 indicates a sleeve inserted into the bolt hole 111 of the spacer 110, and reference numeral 94 indicates a cushioning material provided between the cell unit 60 and the second case 72.

  Referring to FIG. 6, a flat battery 100 is, for example, a flat lithium ion secondary battery, and a laminated power generation element (not shown) in which a positive electrode plate, a negative electrode plate, and a separator are sequentially laminated is a laminate film or the like. It is sealed by a bag-shaped exterior member 100a formed by In the battery 100, one end of an electrode tab (electrode terminal) 100t (a general term for the plus-side electrode tab 100p and the minus-side electrode tab 100m) is electrically connected to the power generation element and led out from the exterior material 100a. Has been. The tab 100t extends on both sides of the battery 100 in the longitudinal direction.

  In the embodiment described above, the cell unit 60 in which the eight flat batteries 100 are stacked is housed in the module case 70 to form the battery module 50. However, the number of the flat batteries 100 forming the cell unit is as follows. For example, a single sheet may be used. The cell unit 60 does not necessarily have to be stored in the module case 70, and a cooling air flow path is provided by providing a gap for every predetermined number or one of the assembled batteries 10 formed by simply stacking the flat batteries 100. The rectifying plate 30 of the first to third examples can be disposed in the cooling air passage with the same configuration. Thus, the low-temperature cooling air that has passed through the side of the battery 100 in the upstream area of the cooling air flow path and has not risen in temperature can be guided to the inside of the battery 100 in the downstream area. The cooling efficiency can be improved by lowering the wind temperature and preventing the wind temperature from becoming high. Therefore, the temperature variation inside the battery 100 can be reduced and the battery 100 can be cooled substantially uniformly, and the lifetime of each battery 100 can be prevented from being reduced.

(A) is a perspective view which shows an example of the assembled battery which concerns on this Embodiment from the front side, (B) is a perspective view which shows the assembled battery from the back side. It is a perspective view which shows the assembled battery after the arrangement | sequence of a battery module and before a bus-bar connection. It is a schematic diagram which shows the arrangement | sequence state of a battery module. It is a perspective view which shows an example of the battery module which is a unit unit at the time of assembling an assembled battery. FIG. 5 is a perspective view showing the battery module shown in FIG. 4 turned upside down and further disassembled. It is a perspective view which shows an example of a flat type battery. It is a top view which shows the state which has arrange | positioned the rectifying plate of the 1st example in the cooling air flow path. It is a top view which shows the state which has arrange | positioned the rectifying plate of the 2nd example in the cooling air flow path. It is a perspective view which shows the state which has arrange | positioned the baffle plate of the 2nd example on a battery module. It is a perspective view which shows the baffle plate of the 2nd example. It is a top view which shows the state which has arrange | positioned the rectifying plate of the 3rd example in the cooling air flow path. It is explanatory drawing which shows the temperature dispersion | variation of the conventional battery module.

Explanation of symbols

10 battery packs,
20 (20a, 20b, 20c, 20d) spacer,
30 (30A, 30B) current plate,
31, 33 separator,
32, 34 Information board,
50 battery module (battery),
51 Cooling air flow path,
51a introduction flow path,
52 Upstream area,
52a The battery side of the upstream region,
52b Inside the upstream battery,
53 downstream area,
53a The side of the battery in the downstream area,
53b The inside of the battery in the downstream area,
100 Flat battery.

Claims (4)

A plurality of flat-type flat batteries having a flat outer shape in which a power generation element in which a positive electrode plate and a negative electrode plate are laminated is sealed inside an outer layer member and electrode terminals connected to the power generation element are led out of the outer layer member are stacked. An assembled battery comprising:
For each predetermined number of the flat battery, a gap as a cooling air flow path into which cooling air flows,
The gap is divided into the battery inner side in the cooling wind passage width direction center side and the battery side in the cooling wind passage width direction outside the battery inner side in the upstream region in the cooling wind passage direction, and lower in the cooling wind passage direction. A battery pack comprising: a rectifying plate that guides the cooling air flowing through the battery side in the basin to the inside of the battery.   The rectifying plate divides the gap into a battery inner side in the cooling wind flow channel width direction central side in the upstream region of the cooling wind flow direction and a battery side in the cooling wind flow channel width direction outer side than the battery inner side. And a guide plate that joins the cooling air that has circulated inside the battery in the upper region of the cooling air flow direction with the cooling air that has circulated through the side of the battery in the lower region of the cooling air flow direction. Item 4. The assembled battery according to Item 1.   The flat battery is stored in a case for each predetermined number of sheets, stacked in a state of being stored in the case, and the gap is provided between adjacent cases in the stacking direction. The assembled battery according to claim 1 or claim 2.   The assembled battery according to claim 3, wherein the gap is formed by a spacer provided between cases adjacent in the stacking direction, and the rectifying plate is formed integrally with the spacer.