JP2006338934A - Package structure of storage capacitor cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance downsizing and weight reduction of a package, while securing voltage and capacity required as the package. <P>SOLUTION: The inside of a case body 2 is sectioned into four blocks via a cross-shaped partition board 6, in which each individual storage capacitor cell 10 is laminated, in a state of being erected in the vertical direction in each block, and held by the partition board 6 and inner side walls of the case body 2 in four directions. In one block, individual cells are mutually connected in parallel, and connection is made in series between the blocks on the upper and lower faces of the package by using an electrode for cell termination processing that is connected to positive and negative output terminals, a cell-collecting electrode for connecting each cell in parallel, and an inter-block connecting electrode for connecting the cell collecting electrodes. According to this, the voltage and capacity required are secured, strength of the whole package is secured, and cell laminating density is raised, thus making it compact can be achieved. Furthermore, heat generated in each cell can be dispersed evenly via the partition board and can be radiated efficiently. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a package structure of a planar power storage cell in which a power storage element is sealed with an exterior material.

  In recent years, flat power storage bodies having a substantially flat rectangular shape such as lithium ion secondary batteries and electric double layer capacitors have been put into practical use, and are considered promising as power sources for various devices due to their high energy density and compactness. Yes.

This type of flat power storage unit is obtained by sealing and sealing a laminate of internal electrodes and an electrolyte layer with, for example, a sheet-like laminate film in which the surface of an aluminum metal layer is insulation-coated with a resin layer. Since it has flexibility and flexibility and lacks rigidity, it needs to be protected from vibration and impact, and is usually used in a case.

  However, since the laminate-type power storage unit has a configuration in which the power storage unit is simply sealed with a laminate film as described above, the external dimensions are likely to vary due to the structure, and accuracy cannot be expected. For this reason, when the power storage cells are stacked and stored in the case, there is a problem that the design tolerance of the case has to be increased, and a dead space is generated.

  In order to deal with such a problem, for example, in Patent Document 1, in an assembled battery in which at least two unit cells are connected, the size of the final assembled battery is reduced by deforming the bus bar after connecting the unit cells by the bus bar. A technique for improving resistance to external vibration / impact while ensuring ease of processing when joining bus bars by disclosing is disclosed.

In Patent Document 2, a laminated battery is installed in a support body as a unit cell of an assembled battery, and the unit cell is molded with a resin, so that vibration transmitted to the laminated battery, which is a unit cell, is attenuated and vibration resistance is improved. Techniques for improving are disclosed.
JP2003-151526A JP 2003-162989 A

  By the way, as disclosed in Patent Document 1, Patent Document 2, and the like, the conventional package structure is intended to improve mechanical performance such as miniaturization, weight reduction, and vibration resistance, and is not necessarily required for the entire package such as an assembled battery. It cannot be said that the mechanical and electrical conditions are taken into consideration. In other words, the package structure that satisfies both the mechanical and electrical conditions includes required voltage / capacity specifications, mountability due to size and weight reduction, vibration resistance, heat resistance, and performance degradation due to cell deterioration. It is necessary to consider the conditions comprehensively.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a package structure of a battery cell capable of reducing the size and weight of the package while ensuring the voltage and capacity required for the package. Yes.

  To achieve the above object, the battery cell package structure according to the present invention comprises a planar power storage cell in which a power storage element is sealed by an exterior material, and a block formed by partitioning the interior with a cross-shaped partition plate. A plurality of power storage cells stacked and housed, and the plurality of power storage cells in each block are arranged in parallel on the surface of the case main body facing the cross-shaped end surface of the partition plate. The electrode for cell assembly connected to, and the inter-block connection electrode for connecting the assembly electrode of each block in series are provided.

  In that case, it is desirable that the partition plate is formed of a material having thermal conductivity to be a transfer path of heat generated in the battery cell, and further, the wall surface orthogonal to the cross-shaped end surface of the partition plate of the case body is insulated. It is desirable to form with a structure. When the cross-shaped end surfaces of the partition plates are arranged in the vertical direction, the power storage cells are preferably stacked with the plurality of power storage cells standing in the vertical direction for each block of the case body.

  The package structure of the battery cell according to the present invention can reduce the size and weight of the package while ensuring the voltage and capacity required for the package.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 9 relate to an embodiment of the present invention, FIG. 1 is an external view of a power storage package, FIG. 2 is a perspective view showing a storage state of a power storage cell, and FIG. 3 is a top view of a connection state in the package. 4 is a side view of the cell termination electrode, FIG. 5 is a side view of the cell assembly electrode, FIG. 6 is a perspective view of the connection state in the package viewed from the bottom side, and FIG. FIG. 8 is a schematic diagram showing the connection state in the package as seen from the upper surface side, and FIG. 9 is a schematic diagram showing the connection state in the package as seen from the lower surface side.

  A power storage package 1 shown in FIG. 1 is a large-capacity power storage package in which prismatic or sheet-type power storage cells are integrated and packaged. For example, the power storage package 1 is applied to a storage battery for starting an engine in a vehicle such as an automobile. Is done. This power storage unit package 1 has a case structure in which lids are fitted on the upper and lower surfaces of a box-shaped case body 2. Positive and negative polarity marks are displayed on the upper lid 3, and Positive and negative output terminals 4 and 5 protrude from the position corresponding to the polarity mark.

  As shown in FIG. 2, a partition plate 6 having a cross shape in the horizontal direction is disposed inside the case body 2, and the interior of the case body 2 is partitioned into four blocks by the partition plate 6. ing. Each block stores a plurality of flat rectangular power storage cells 10 in which power storage elements are sealed with an exterior material such as a laminate film. In each block, the individual power storage cells 10 are connected in parallel to each other, and the four blocks are connected in series and connected to the positive and negative output terminals 4 and 5.

  For example, in order to obtain a voltage 8V to 12.5V required for automobiles by setting the terminal voltage of the power storage cell 10 as a single cell to 2.2V to 3.8V, it is necessary to connect at least four cells in series. is there. Normally, when configuring a battery pack or the like using a plurality of cells, it is common to connect a plurality of cells in series connected in parallel and use as a battery. In each block, five power storage cells 10 are accommodated, and a state in which the blocks are connected in parallel in each block is used as one power storage pack to complete one block. Then, by connecting four power storage packs in series, a voltage of 8V to 12.5V and a battery capacity required for automobiles are obtained.

  Here, in the case where an assembled battery is configured using 20 cells as described above, when 5 blocks are connected in parallel with 4 blocks connected in series (referred to as “A system”), 5 Compared with the case where 4 blocks connected in parallel are connected in series (referred to as “B method”), the A battery and the B battery both have the same terminal voltage and the same battery capacity. Can do.

  However, in the B method, since cells are connected in parallel in each block, the internal resistance error in each block is smaller than in the A method, and as a result, variations in terminal voltage can be suppressed. This is the same when the internal resistance of the cell increases due to deterioration over time. When viewed in units of blocks, changes in internal resistance are integrated in series connection in the A method, whereas parallel connections in the B method. Thus, the change in internal resistance is suppressed by the number of cells. When viewed as a whole package, the possibility of all blocks being deteriorated at the same time is extremely small. Therefore, the B method, which has a smaller influence on a block basis, is less than the A method, which has a larger influence on a block basis. It can be said that it is difficult to be affected by deterioration as a whole.

  Further, when a plurality of cells are connected in series, a balancer circuit for equalizing the voltages of the cells connected in series is required to prevent the output voltage from being biased due to variations in the internal resistance and voltage of the cells. In the A method, 20 balancer circuits are required, which causes an increase in cost, whereas in the B method, the number of balancer circuits is only four, and the cost can be reduced.

  As shown in FIGS. 2, 3, and 6, the storage battery cells 10 inside the case body 2 are stacked with the individual storage battery cells 10 standing in the vertical direction for each block. The body pack is held in four directions by the partition plate 6 and the inner wall of the case body 2. The case main body 2 is formed of a heat insulating material to prevent inflow of heat from the outside, and the side wall is formed of, for example, a vacuum heat insulating structure. On the other hand, the partition plate 6 functions as a holding body that holds the cells of each block and a heat transfer path that transfers heat generated in the cells of each block, and is formed of a material having rigidity and thermal conductivity. It is set to a thickness required for securing rigidity and a heat transfer path.

  That is, for each block in which the inside of the case body 2 is partitioned in a cross shape by the partition plate 6, the power storage cells 10 are stacked in a vertical state, thereby ensuring the strength of the entire package and the power storage cell 10. Compactness can be achieved by increasing the lamination density. At the same time, by holding the cells of each block via the partition plate 6, the heat generated in each cell can be uniformly distributed to enable efficient heat dissipation and prevent a temperature difference between the upper and lower cells. be able to.

  As shown in FIG. 3, the series connection processing between the blocks is performed on each of the two cell termination processing electrodes 15 connected to the positive and negative output terminals 4 and 5, respectively, as shown in FIG. This is performed by using two cell assembly electrodes 20 for connecting cells in parallel, and a rectangular plate-shaped inter-block connection electrode 25 for connecting the two cell assembly electrodes 20.

  As shown in FIG. 4, the cell termination electrode 15 is formed by bending a rectangular metal plate into an L shape, and the electrode terminals of each power storage cell 10 are assembled and connected via a bus bar or the like. The terminal connection part 15a and the output terminal connection part 15b connected and fixed to the support part 4a that supports the output terminal 4 (or the support part 5a that supports the output terminal 5) are provided. As shown in FIG. 5, the cell assembly electrode 20 is formed by bending a rectangular metal plate into an L shape, and the electrode terminals of each power storage cell 10 are assembled and connected via a bus bar or the like. It has a cell terminal connection portion 20a and a block connection portion 20b connected to the inter-block connection electrode 25.

  The inter-block connection electrodes 25 are formed in a rectangular flat plate shape, and are fixed to an upper plate 30 whose side edges are fitted and fixed to the case body 2 on the back side of the upper lid 3 (see FIG. 3). ). The block connection portions 20b of the two cell assembly electrodes 20 are fixed to one side of the inter-block connection electrode 25, and the cell terminal connection portions 15a of the two cell termination electrodes 15 are disposed on the back side of the opposite sides. Is insulated from the inter-block connection electrode 25.

  On the other hand, on the lower surface side of the package, as shown in FIG. 6, the series connection processing between the blocks is performed using the four cell assembly electrodes 20 and the two inter-block connection electrodes 40 sandwiching the insulating material 35 therebetween. That is, on the lower surface side of the package, blocks adjacent to each other in the stacking direction of the power storage cells 10 are connected in series from the cell assembly electrode 20 to the cell assembly electrode 20 via the inter-block connection electrode 40. The two inter-block connection electrodes 40 are insulated by an insulating material 35.

  The two inter-block connection electrodes 40 sandwiching the insulating material 35 are fixed to a bottom plate 45 whose side edges are fitted and fixed to the case body 2 on the lower surface of the package.

  As shown in FIG. 7, the battery pack Pi (i = 1, 2, 3, 4) schematically representing a stacked body of five power storage cells 10 as shown in FIG. Will be described. The notation “+” and “−” of the battery pack Pi in FIG. 7 indicates the output polarity as a complete state in which the + pole terminal and the −pole terminal of each battery cell 10 are assembled and connected in parallel. Yes.

  As shown in FIGS. 8 and 9, the positive output terminal 4 as the power storage package 1 is connected to the positive electrode of the power storage pack P <b> 1 via the cell termination processing electrode 15, and − The pole is connected from the cell assembly electrode 20 to the positive electrode cell assembly electrode 20 of the battery pack P2 via the inter-block connection electrode 40 on the lower surface side of the package.

  The negative electrode of the battery pack P2 is connected from the cell assembly electrode 20 to the inter-block connection electrode 25 on the upper surface side of the package, and the positive electrode cell assembly electrode 20 of the power storage pack P3 from the inter-block connection electrode 25. Connected to. Then, on the lower surface side of the package, the negative electrode of the power storage pack P3 is connected from the cell assembly electrode 20 to the positive electrode cell assembly electrode 20 of the power storage pack P4 via the inter-block connection electrode 40. The negative pole of P4 is connected to the negative output terminal 5 via the cell termination electrode 15 on the upper surface side of the package, and the entire connection by the series connection of the battery packs P1 to P4 is completed.

  As described above, in the present embodiment, the inside of the case body 2 that stores the power storage cell 10 is divided into blocks by the cross-shaped partition plate 6, and the power storage cells 10 are stacked in parallel for each block. Each block is connected in series after being connected to a complete state. Thereby, while ensuring the voltage and capacity | capacitance requested | required as the whole package, size reduction and weight reduction can be achieved, the heat resistance improvement by forming the partition plate 6 as a thermal radiation path, and the parallel connection for every block It is possible to reduce the influence of cell deterioration (reduce the influence due to an increase in internal resistance) and the like, and it is possible to construct a power storage package suitable for mounting on a vehicle or the like.

External view of power storage package The perspective view which shows the accommodation state of an electrical storage body cell The perspective view which looked at the connection state in a package from the upper surface side Side view of cell termination electrode Side view of cell assembly electrode The perspective view which looked at the connection state in a package from the lower surface side Schematic representation of the battery pack Schematic view of the connection state in the package as seen from the top side Schematic view of the connection status inside the package as seen from the bottom side

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power storage package 2 Case main body 6 Partition plate 10 Power storage cell 20 Electrode for cell assembly 25 Electrode for connection between blocks 40 Electrode for connection between blocks

Claims (4)

A planar power storage cell in which a power storage element is sealed with an exterior material;
For each block formed by partitioning the inside with a cross-shaped partition plate, a case body that stores and stacks a plurality of the power storage cells,
A cell assembly electrode for connecting the plurality of power storage cells in each block in parallel and a collection electrode for each block are connected in series on the surface of the case body facing the cross-shaped end surface of the partition plate. A battery cell package structure, wherein inter-block connection electrodes are provided.   2. The battery cell package structure according to claim 1, wherein the partition plate is formed of a material having thermal conductivity to serve as a transfer path of heat generated in the power storage cell.   3. The package structure for a power storage cell according to claim 1, wherein a wall surface orthogonal to the cross-shaped end surface of the partition plate of the case body is formed of a heat insulating structure.   The cross-shaped end face of the partition plate is arranged in a vertical direction, and the plurality of power storage cells are stacked in a vertical state for each block of the case body. The package structure of the battery cell according to any one of the above.

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