JP2013008557A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack capable of preventing decrease of performance and service life thereof.SOLUTION: A battery pack 20 has plural battery blocks 1a-1c electrically connect to each other in series; and each battery block includes plural single cells 10 electrically connected to each other in parallel. All single cells 10 are disposed in parallel to each other. When the single cells 10 of the battery pack 20 are sorted from the one located closest to the disposition center of the single cells in the battery pack 20, a battery block 1a, which includes a single cell 10 located closer to the disposition center than a middle single cell 10c located at the intermediate position, includes a single cell 10 which is located farther from the dispose center than the middle single cell 10c.

Description

  The present invention relates to an assembled battery.

  An assembled battery is known in which a plurality of single cells are electrically connected in parallel or in series to obtain high output and high electric capacity. In this type of assembled battery, when an abnormal unit cell having a higher internal resistance or lower electric capacity than other unit cells is included, the performance and life of the assembled battery are significantly deteriorated.

  Therefore, in the assembled battery described in Patent Document 1 below, a plurality of battery blocks (parallel connection sets) configured by electrically connecting a plurality of single cells in parallel are electrically connected in series. Thereby, even if an abnormal cell is included in the assembled battery, the abnormal cell is electrically connected in parallel with other normal cells in the battery block, and the internal resistance, electric capacity, etc. Since it is averaged, the deterioration of the performance and life of the assembled battery due to the abnormal cell is suppressed.

JP-A-8-241705

  By the way, it is known that a unit cell used for an assembled battery has an increase in internal resistance and deterioration in cycle characteristics under a high temperature environment. In the case of a battery pack, the battery temperature of each battery cell varies depending on the arrangement position. For example, a battery cell positioned near the outer periphery of the battery pack is cooler than other battery cells, The single cell located in the vicinity) has a higher temperature than the other single cells.

  Therefore, in the assembled battery described in Patent Document 1, when all the cells in the battery block are arranged near the center of the assembled battery, all the cells in the battery block are due to the high battery temperature. May become an abnormal cell. As described above, in the assembled battery described in Patent Document 1, when all of the battery blocks are abnormal cells, it is not possible to suppress deterioration of the performance and life of the assembled battery.

  The objective of this invention is providing the assembled battery which can suppress deterioration of the performance and lifetime of an assembled battery more.

  In order to solve the above problems, the assembled battery in the present invention is an assembled battery in which a plurality of battery blocks configured by electrically connecting a plurality of single cells in parallel are electrically connected in series. And, all of the cells of the assembled battery are arranged in parallel with each other, and when the cells of the assembled battery are sorted in the order of the distance from the arrangement center of the cells in the assembled battery, The battery block having the unit cell that is closer to the array center than the intermediate unit cell in the middle has the unit cell that is farther from the array center than the intermediate unit cell. To do.

  According to the above configuration, the battery block having the unit cells that are close to the array center and have a high battery temperature has the unit cells that are far from the array center and have a low battery temperature. Therefore, it is possible to reduce the possibility that all the cells in the battery block become abnormal cells due to the high temperature of the battery, and as a result, further suppress the deterioration of the performance and life of the assembled battery. be able to.

  Moreover, in this invention, the said battery block which has the said single battery with the shortest distance from the said array center may have the said single battery with the furthest distance from the said array center. According to the above configuration, the battery block having the single battery with the high battery temperature arranged closest to the array center has the single battery with the low battery temperature arranged farthest from the array center. The possibility that all the single cells of the battery block become abnormal cells can be further reduced, and as a result, the deterioration of the performance and life of the assembled battery can be further suppressed.

  In the present invention, the battery block is configured such that a difference between a maximum value and a minimum value of values obtained by adding the distances between the unit cells in the assembled battery and the unit cells for each battery block is minimized. Each may be configured. According to said structure, all the single cells which comprise a battery block are not arrange | positioned near the outer periphery of an assembled battery, or the center vicinity of an assembled battery. Therefore, it is possible to reduce the possibility that all the cells in the battery block become abnormal cells due to the high battery temperature, and abnormal cells due to the low battery temperature. Can also be reduced. As a result, it is possible to further suppress deterioration in performance and life of the assembled battery.

  Further, in the present invention, the unit cells of the assembled battery are arranged in line symmetry with respect to a reference line passing through the arrangement center, and the assembled battery includes each of the unit cells constituting an arbitrary battery block. And a battery block composed of a plurality of the unit cells that are line-symmetric with each other.

  Further, in the present invention, the unit cells of the assembled battery are arranged rotationally symmetrical with respect to the arrangement center, and the assembled battery is rotationally symmetric with each of the unit cells constituting the arbitrary battery block. You may have the battery block comprised from the said several cell.

  It is possible to further suppress deterioration in performance and life of the assembled battery.

It is a disassembled perspective view of the assembled battery which concerns on 1st Embodiment of this invention, and the housing | casing which accommodates an assembled battery. It is a circuit diagram of the assembled battery shown in FIG. FIG. 2 is a front view of the assembled battery shown in FIG. 1 as viewed from a direction perpendicular to the arrangement surface of the unit cells. (A) is a figure explaining the battery temperature of the single battery of an assembled battery, (b) is a figure which shows the result of having sorted the single battery of the assembled battery in order of distance from an array center. It is a figure explaining the reference example of the structure of the battery block in an assembled battery. It is explanatory drawing explaining the structure of the battery block in the assembled battery which concerns on 1st Embodiment of this invention. It is a figure explaining the modification of 1st Embodiment. It is a circuit diagram of the assembled battery which concerns on 2nd Embodiment. It is the front view seen from the direction orthogonal to the arrangement surface of a cell of the battery pack concerning a 2nd embodiment. (A) is a figure explaining the structure of the battery block of the assembled battery which concerns on 2nd Embodiment, (b) is a figure which shows the result of having sorted the cell of the assembled battery in the order with the short distance from the array center. It is a circuit diagram of the assembled battery which concerns on 3rd Embodiment. It is the front view seen from the direction orthogonal to the arrangement surface of a cell of the battery pack concerning a 3rd embodiment. (A) is a figure explaining the structure of the battery block of the assembled battery which concerns on 3rd Embodiment, (b) is a figure which shows the result of having sorted the cell of the assembled battery in order of distance from the array center. It is a figure explaining a modification.

(First embodiment)
Hereinafter, the assembled battery according to the first embodiment of the present invention will be described with reference to FIGS.

  The assembled battery 20 is accommodated in the housing 50 as shown in FIG. Moreover, the assembled battery 20 is configured by electrically connecting a plurality of battery blocks 1 configured by electrically connecting a plurality of cylindrical unit cells 10 in parallel as shown in FIG. ing. In the present embodiment, the assembled battery 20 is configured by electrically connecting three battery blocks 1a to 1c in series. Moreover, each battery block 1a-1c is comprised by connecting the three cell 10 electrically in parallel.

  The unit cell 10 is a non-aqueous secondary battery such as a lithium ion battery. The unit cell 10 includes an electrode body (not shown) having a positive electrode and a negative electrode, and a cylindrical battery exterior portion 12 that houses the electrode body. The positive electrode and the negative electrode of the electrode body are respectively connected to the positive electrode terminal 11a and the negative electrode terminal 11b exposed to the outside of the unit cell.

  The housing 50 is configured by combining a bottom plate 51, a pair of side plates 52, an upper plate 53, a front plate 54 and a rear plate 55. Each of the front plate 54 and the rear plate 55 is provided with a plurality of claws 60 that hold one end of each unit cell 10 in the axial direction. Each unit cell 10 is arranged in parallel with the battery exterior parts 12 in contact with each other between adjacent unit cells 10 by holding both ends in the axial direction by the claws 60 of the front plate 54 and the rear plate 55. Yes. In other words, the single cells 10 are arranged in parallel with their axial directions coinciding with each other. In the present embodiment, nine unit cells 10 are arranged in a 3 × 3 grid on the arrangement surface (XY plane) of the unit cells 10 of the assembled battery 20. Specifically, the upper and lower three unit cells 10 are arranged such that the axis centers of the unit cells coincide with each other in the Y direction (row direction) in FIG. Then, three cell arrays composed of the three upper and lower cells are arranged in the Y direction (column direction) in FIG. Thereby, as for the assembled battery 20, the external shape of the arrangement | sequence surface has comprised the substantially square. In the following, description will be made using an XY coordinate system in which the coordinates (axis center coordinates) of the unit cells 10 arranged at the lower left in FIG. 3 are (1, 1) and the unit cell 10 diameter is normalized to 1. .

  Here, at the time of charging / discharging of the assembled battery 20, each of the unit cells 10 generates heat. For this reason, the unit cell 10 located near the arrangement center (hereinafter simply referred to as the arrangement center) of the unit cells 10 of the assembled battery 20 has a higher battery temperature than the other unit cells, and the outer periphery of the assembly battery 20 from the arrangement center. The battery temperature becomes lower as it goes to. The array center is defined as follows. First, the shortest distance D to the outer peripheral line L formed by connecting the axial centers of the unit cells 10 forming the outer periphery of the assembled battery 20 between the adjacent unit cells 10 is the largest, and the outer peripheral line L The point on the array surface that is enclosed is the maximum distance point. In the present embodiment, since the locus of the outer peripheral line L is a square, the maximum distance point is only one point on the arrangement surface as shown in FIG. The maximum distance point is set as the array center. In other words, the center of the arrangement is a point in the assembled battery 20 where the temperature of the assembled battery 20 is highest due to the heat generated by each unit cell 10. As will be described later with reference to FIG. 9, when there are a plurality of maximum distance points and a maximum distance line is formed by a set of these plurality of maximum distance points, the center position of the maximum distance line is determined. The array center.

  In the present embodiment, the array center is the coordinates (2, 2). Here, when the unit cells 10 of the assembled battery 20 are sorted in the order of the distance from the center of the array, the result is as shown in FIG. It should be noted that the cells having the same distance from the array center are in the same order. The unit cell 10 in the middle of the sort order sorted in this way is referred to as an intermediate unit cell 10c. In the present embodiment, as shown in FIGS. 4A and 4B, the unit cell 10 having coordinates (1, 2), (2, 1), (2, 3), and (3, 2) is intermediate. A unit cell 10c is obtained.

  The unit cell 10 closer to the arrangement center than the intermediate unit cell 10c is referred to as an inner unit cell, and the unit cell 10 farther from the arrangement center than the intermediate unit cell 10c is referred to as an outer unit cell. In other words, the unit cell 10 whose sorting order is before the intermediate unit cell 10c is the inner unit cell, and the unit cell 10 after the intermediate unit cell 10c is the outer unit cell. In this embodiment, as shown in FIGS. 4A and 4B, the unit cell 10 at coordinates (2, 2) is the inner unit cell, and the coordinates (1, 1), (1, 3), ( The single cells 10 of (3, 1) and (3, 3) are outer single cells. The unit cell 10 at the coordinates (2, 2), which is the inner unit cell, is the unit cell that is the closest to the arrangement center, and the unit cell that has the highest battery temperature in the assembled battery 20 (hereinafter, the highest temperature). A single cell 10a). On the other hand, the unit cell 10 of coordinates (1, 1), (1, 3), (3, 1), (3, 3), which is the outer unit cell, is the unit cell that is the farthest from the array center. In other words, the battery cell 10 has the lowest battery temperature in the assembled battery 20 (hereinafter, the lowest temperature battery cell 10b). Note that the battery temperature of the intermediate cell 10c at coordinates (1, 2), (2, 1), (2, 3), (3, 2) is the battery temperature of the highest temperature cell 10a and the lowest temperature cell 10b. It becomes the temperature between the batteries.

  Here, referring to FIG. 5, similarly to the assembled battery 20 of the present embodiment, nine unit cells 10 are arranged in a 3 × 3 grid on the arrangement surface, and 3 battery blocks are provided. Consider an assembled battery 100 configured by electrically connecting 1a to 1c in series. Further, it is assumed that each single cell 10 constituting each battery block 1 of the assembled battery 100 is positioned in the assembled battery 100 as shown in FIG. In addition, the code | symbol described in the single battery 10 in FIG. 5 represents the battery block 1 which the single battery 10 comprises. Therefore, for example, the battery block 1a is configured by electrically connecting three unit cells 10 having coordinates (1, 1), (1, 2), and (1, 3) in parallel.

  In the assembled battery 100, the battery block 1b is composed of one highest temperature unit cell 10a and two intermediate unit cells 10c, and does not have the lowest temperature unit cell 10b. There is a high possibility that all of the unit cells 10 to be operated become abnormal unit cells because the battery temperature is high. As described above, the assembled battery 100 has a high possibility that all the unit cells 10 constituting the battery blocks 1a to 1c are abnormal cells because the battery temperature is high. Deterioration of performance and life cannot be sufficiently suppressed.

  Therefore, in the present embodiment, as shown in FIG. 6, the battery block 1a having the highest temperature unit cell 10a that is the inner unit cell is configured to have the lowest temperature unit cell 10b that is the outer unit cell. . As a result, the possibility that all the single cells 10 of the battery block 1a become abnormal single cells due to the high battery temperature can be reduced. As a result, the performance and life of the assembled battery 20 can be reduced. Deterioration can be further suppressed.

  Here, it is known that a unit cell of an assembled battery may become an abnormal unit cell due to a voltage drop or a decrease in battery capacity in a low temperature environment. Therefore, as a modification of the present embodiment, in order to reduce the possibility that all the cells in the battery block become abnormal cells due to the low battery temperature, an assembled battery 20a shown in FIG. In addition, the battery block 1a having the highest temperature unit cell 10a is configured to have the lowest temperature unit cell 10b, and the value obtained by adding the distance between the array center and the axis center of each unit cell 10 for each battery block 1 ( Hereinafter, each of the battery blocks 1 may be configured such that the difference between the maximum value and the minimum value of the battery block total distance (hereinafter referred to as the total distance difference) is minimized. This will be specifically described below. In the assembled battery 20a shown in FIG. 7, the battery block total distance of the battery block 1a is the coordinates (2, 2) of the array center and the coordinates (1, 1) of the individual cells 10 constituting the battery block 1a ( 2, 2) and (3, 3), 2√2 (= √2 + 0 + √2). Similarly, the battery block total distance of the battery blocks 1b and 1c is 2 + 2√2, 2 + √2, respectively. Accordingly, the total distance difference is 2-√2 (= (2 + √2) − (2√2)). 2-√2 that is the total distance difference is made smaller than the total distance difference when the battery blocks 1a to 1c are configured by combining the other single cells 10 respectively. By doing so, the battery temperature of all the single cells 10 of the battery block 1 is higher than that of the other battery blocks 1 among the battery blocks 1 constituting the assembled battery 20a. Alternatively, it is possible to reduce an increase in the possibility of an abnormal cell due to the low temperature.

  Specifically, the assembled battery 20 shown in FIG. 6 and the assembled battery 20a shown in FIG. 7 will be compared and described. In addition, in the assembled battery 20 shown in FIG. 6, since the total distance difference is 1 (= (2 + √2) − (1 + √2)), it is larger than the total distance difference of the assembled battery 20a.

  As shown in FIGS. 6 and 7, each of the assembled batteries 20 and 20a has one battery block 1 including two lowest temperature single cells 10b. In the assembled battery 20a shown in FIG. 7, the battery block 1a having two lowest temperature single cells 10b includes the two lowest temperature single cells 10b and one highest temperature single cell 10a. On the other hand, in the assembled battery 20 shown in FIG. 6, a battery block 1b having two lowest temperature single cells 10b includes the two lowest temperature single cells 10b and one intermediate single cell 10c. Therefore, the possibility that all of the single cells 10 of the battery block 1 including the two lowest temperature single cells 10b become abnormal single cells due to the low battery temperature is that the assembled battery 20a is the assembled battery 20a. Low compared to

  Similarly, as shown in FIGS. 6 and 7, each of the assembled batteries 20 and 20 a has one battery block 1 including one maximum temperature unit cell 10 a. In the assembled battery 20a shown in FIG. 7, the battery block 1a having the highest temperature single cell 10a is composed of two lowest temperature single cells 10b and one highest temperature single cell 10a. On the other hand, in the battery pack 20 shown in FIG. 6, the battery block 1a having one highest temperature cell 10a includes one highest temperature cell 10a, one lowest temperature cell 10b, and one intermediate. It is comprised from the cell 10c. Therefore, the possibility that all the single cells 10 of the battery block 1 including one highest temperature single cell 10a become abnormal single cells due to the high battery temperature is that the assembled battery 20a is more likely to be the assembled battery 20a. Low compared to

  In this way, by configuring each battery block 1 such that the total distance difference of the battery block total distance obtained by summing the distance between the array center and the axis center of each cell 10 for each battery block 1 is minimized, Among the battery blocks 1 constituting the assembled battery 20 a, the specific battery block 1 has a higher or lower battery temperature than the other battery blocks 1. It is possible to reduce an increase in the possibility of an abnormal cell due to. Thereby, deterioration of the performance and lifetime of an assembled battery can be suppressed more.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. In the second embodiment, the main difference from the first embodiment is that, as shown in FIG. 8, six battery blocks in which the assembled battery 25 is configured by electrically connecting five unit cells 10 in parallel. 2 (2a to 2f) are electrically connected in series. Below, the same code | symbol is attached | subjected about the location same as 1st Embodiment mentioned above, and the description is abbreviate | omitted suitably.

  In the present embodiment, as shown in FIG. 9, 30 unit cells 10 are arranged in a 5 × 6 grid on the arrangement surface of the unit cells 10 of the assembled battery 25. Specifically, the upper and lower unit cells 10 are arranged such that the axis centers of the unit cells coincide with each other in the Y direction (row direction) in FIG. 9. Then, six cell arrays composed of the five upper and lower cells are arranged in the Y direction (column direction) in FIG. Thereby, as for the assembled battery 25, the external shape of the arrangement surface has comprised the substantially rectangle. Further, each of the single cells 10 is arranged in line symmetry with respect to a reference line (X = 3.5) passing through the arrangement center.

  The array center in this embodiment is defined as follows. As shown in FIG. 9, since the locus of the outer peripheral line L is a rectangle, there are a plurality of maximum distance points, and the maximum distance line is formed by a set of these plurality of maximum distance points. Specifically, a maximum distance line connecting the coordinates (4, 3) to the coordinates (4, 3) is formed. When the maximum distance line is formed in this way, the array center is set as the center position of the maximum distance line. In the present embodiment, the array center is the coordinates (3.5, 3). Accordingly, as shown in FIG. 10A, the two unit cells 10 having coordinates (3, 3) and (4, 3) located closest to the array center become the highest temperature unit cell 10a, and the array center The four unit cells 10 having the coordinates (1, 1), (1, 5), (6, 1), and (6, 5) located farthest from the center become the lowest temperature unit cell 10b.

  Here, when the unit cells 10 of the assembled battery 25 are sorted in the order of the distance from the center of the array, as in the above-described embodiment, the result is as shown in FIG. When there is a difference in the distance from the highest temperature unit cell 10a closest to each unit cell 10 between the unit cells 10 having the same distance from the center of arrangement, the distance from the highest temperature unit cell 10a is closer. Sorting is done so that the unit cell 10 comes first. Specifically, for example, the unit cell 10 at coordinates (1, 3) and the unit cell 10 at coordinates (2, 1) have the same distance from the center of the array, but the unit cell 10 at coordinates (1, 3) Since the distance from the highest temperature unit cell 10a of the coordinate (3, 3) is shorter, the unit cell 10 of the coordinate (1, 3) is the coordinate (2, 1) as shown in FIG. Sorting so that it comes before the single cell 10. The unit cell 10 in the middle of the sort order sorted in this way is referred to as an intermediate unit cell 10c. In the present embodiment, as shown in FIGS. 10A and 10B, the unit cell 10 having coordinates (3, 1), (3, 5), (4, 1), and (4, 5) is intermediate. A unit cell 10c is obtained.

  As in the above-described embodiment, the unit cell 10 closer to the arrangement center than the intermediate unit cell 10c is referred to as the inner unit cell, and the unit cell 10 farther from the arrangement center than the intermediate unit cell 10c is referred to as the outer unit cell.

  The assembled battery 25 is configured such that the battery block 2 having the inner cell has the outer cell. For example, the battery block 2c having an inner cell of coordinates (4, 4) and (5, 2) is configured to have an outer cell of coordinates (1, 5). As a result, the battery temperature of the inner unit cell that is close to the array center is different from the battery temperature of the outer unit cell that is far from the array center, so all the cells in the battery block can be abnormal cells. As a result, it is possible to further suppress deterioration in performance and life of the assembled battery.

  The assembled battery 25 has a battery block 2 composed of the unit cells 10 that are line-symmetric with each of the unit cells 10 constituting each battery block 2. Specifically, for example, the cell 10 of the coordinates (2, 1), (3, 3), (5, 4), (6, 1), (6, 3) constituting the battery block 2a is a battery. The cells (5, 1), (4, 3), (2, 4), (1, 1), (1, 3) constituting the block 2b and the reference line (X = 3.5) are respectively set. It is line symmetric as a reference. Thereby, the battery temperature of each single battery 10 which comprises the battery block 2a, and the battery temperature of each single battery 10 which comprises the battery block 2b can be made substantially equal. Similarly, between the battery blocks 2c and 2d and between the battery blocks 2e and 2f, the unit cells 10 constituting each of them are axisymmetric.

  Furthermore, the battery pack 2a, 2b having the highest temperature unit cell 10a closest to the array center has the lowest temperature unit cell 10b farthest from the array center, and the assembled battery 25 includes the array center. Each battery block 2 is configured such that the total distance difference between the battery block total distances for each battery block 2 is the minimum distance from the axis center of each unit cell 10. Thereby, the possibility that all the single cells 10 of the battery block 2 become abnormal single cells can be further reduced, and as a result, the deterioration of the performance and life of the assembled battery 25 can be further suppressed.

(Third embodiment)
Next, a third embodiment will be described with reference to FIGS. In the third embodiment, the main difference from the first embodiment is that, as shown in FIG. 11, the battery pack 30 includes four battery blocks configured by electrically connecting four unit cells 10 in parallel. 3 (3a to 3d) is electrically connected in series. Below, the same code | symbol is attached | subjected about the location same as 1st Embodiment mentioned above, and the description is abbreviate | omitted suitably.

  In the present embodiment, as shown in FIG. 12, on the arrangement surface of the unit cells 10 of the assembled battery 30, 16 unit cells 10 are arranged in a 4 × 4 grid. Specifically, the upper and lower four unit cells 10 are arranged such that the axis centers of the unit cells coincide with each other in the Y direction (row direction) in FIG. Then, four cell arrays composed of the four upper and lower cells are arranged in the Y direction (column direction) in FIG. Thereby, as for the assembled battery 30, the external shape of the arrangement | sequence surface has comprised the substantially square. In addition, each of the single cells 10 is arranged in a rotationally symmetrical manner with a four-fold symmetry with respect to the arrangement center of the single cells of the assembled battery 25.

  The array center in the present embodiment is coordinates (2.5, 2.5) as shown in FIG. Here, when the unit cells 10 of the assembled battery 30 are sorted in the order of the distance from the array center, as in the above-described embodiment, the result is as shown in FIG. And the cell 10 in the middle of the sorted sort order is set as the intermediate cell 10c. In the present embodiment, as shown in FIGS. 13A and 13B, coordinates (1, 2), (1, 3), (2, 1), (2, 4), (3, 1) , (3, 4), (4, 2), and (4, 3) unit cell 10 is an intermediate unit cell 10c. Accordingly, as shown in FIG. 13, four unit cells 10 having coordinates (2, 2), (2, 3), (3, 2), and (3, 3) that are the closest to the array center are arranged on the inner side. It becomes the highest temperature unit cell 10a which is a battery, and the four unit cells 10 of coordinates (1, 1), (1, 4), (4, 1), (4, 4) which are the farthest from the array center are outside. It becomes the lowest temperature unit cell 10b which is a unit cell.

  In the battery block 3 of the assembled battery 30, each of the battery blocks 3a to 3d having the highest temperature unit cell 10a is configured to have the lowest temperature unit cell 10b. Moreover, each battery block 3a-3d is comprised so that it may become the rotational symmetry of 4 times symmetry mutually. Specifically, for example, the unit cell 10 of coordinates (4, 1) constituting the battery block 3a constitutes the unit cell 10 and the battery block 3c (1, 1) constituting the battery block 3b (1, 1). The unit cell 10 of 4) and the unit cell 10 of (4, 4) constituting the battery block 3d are respectively rotationally symmetric. Further, each battery block 3 is configured such that the difference between the maximum value and the minimum value of the total battery block distance for each battery block 3 is minimized with respect to the distance between the array center and the axis center of each unit cell 10. Yes. Thereby, the possibility that all the single cells of the battery block become abnormal single cells can be reduced, and as a result, deterioration of the performance and life of the assembled battery can be further suppressed.

  Furthermore, the battery blocks 3a to 3d are each positioned in each of the regions A to D that are rotationally symmetric with respect to each other, which are divided by a line extending in the X direction passing through the array center and a line extending in the Y direction passing through the array center. A battery 10 is included. For example, the battery block 3a is positioned at the coordinates (2, 3) of the area A, the coordinates (4, 3) of the area B, the coordinates (2, 1) of the area C, and the coordinates (4, 1) of the area D. The unit cell 10 is configured. Accordingly, only a part of these four regions is positioned in one region when the temperature is lower or higher than the other regions due to external thermal influences or the like. Compared with the case where only the unit cell 10 is used, the possibility that all the unit cells 10 of the battery block 3 are abnormal cells can be further reduced.

  The embodiments of the present invention have been described above, but only specific examples are illustrated, and the present invention is not particularly limited. Specific configurations and the like can be appropriately changed in design. Further, the actions and effects described in the embodiments of the invention only list the most preferable actions and effects resulting from the present invention, and the actions and effects according to the present invention are described in the embodiments of the present invention. It is not limited to what was done.

  For example, in the above-described embodiment, the unit cells of the assembled battery are arranged so that the outer shape of the arrangement surface of the assembled battery is a substantially square shape or a substantially rectangular shape, but all the unit cells are arranged in parallel to each other. If it is, it will not be limited to this in particular. For example, the cells 10 may be arranged by hexagonal close-packing on the arrangement surface. Further, the cells 10 of the assembled battery 30 may be arranged so that the locus of the outer peripheral line L forms a circle or an n-gon (n is an integer of 3 or more) as shown in the assembled battery 35 of FIG. . In the battery pack 35 shown in FIG. 14, the unit cell 10 at coordinates (3, 3) is the highest temperature unit cell 10a, and the unit cell 10 at coordinates (6, 1) is the lowest temperature unit cell 10b.

  Moreover, in the above-mentioned embodiment, although the single battery 10 is a cylindrical battery, it is not specifically limited to this, A rectangular parallelepiped battery may be sufficient.

1, 2, 3 Battery block 10 Single battery 20, 20a, 25, 30, 35 Assembly battery

Claims (5)

A plurality of battery blocks configured by electrically connecting a plurality of single cells in parallel, an assembled battery electrically connected in series,
All the cells of the assembled battery are arranged in parallel with each other,
When the unit cells of the assembled battery are sorted in the order of the distance from the array center of the unit cells in the assembled battery, the unit cell is closer to the array center than the intermediate unit cell in the middle The battery block having the unit cell includes the unit cell that is farther from the array center than the intermediate unit cell.   2. The assembled battery according to claim 1, wherein the battery block having the single cells closest to the array center includes the single cells farthest from the array center.   Each of the battery blocks is configured such that the difference between the maximum value and the minimum value of the values obtained by adding the distances between the unit cells in the assembled battery and the unit cells for each battery block is minimized. The assembled battery according to claim 1, wherein the assembled battery is provided. The unit cells of the assembled battery are arranged symmetrically with respect to a reference line passing through the arrangement center,
4. The battery pack according to claim 1, wherein the battery pack includes a battery block including a plurality of the single cells that are symmetrical with each of the single cells constituting the arbitrary battery block. The assembled battery according to claim 1. The unit cells of the assembled battery are arranged rotationally symmetrical with respect to the arrangement center,
4. The battery pack according to claim 1, wherein the battery pack includes a battery block including a plurality of the single cells that are rotationally symmetric with each of the single cells constituting the arbitrary battery block. The assembled battery according to claim 1.

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