WO2014109041A1

WO2014109041A1 - Cell module and cell system using same

Info

Publication number: WO2014109041A1
Application number: PCT/JP2013/050351
Authority: WO
Inventors: 本田　光利; 晋山内; 賢治武田; 田中　融
Original assignee: 株式会社日立製作所
Priority date: 2013-01-11
Filing date: 2013-01-11
Publication date: 2014-07-17

Abstract

In order to prevent short-circuit current due to nail penetration, a fuse must be provided between cells. Therefore, the number of fuses must correspond to the number of cells. This cell module is characterized in having: a first cell group in which at least two cells are aligned in one row in a plane, and are electrically connected in series; and a second cell group in which at least two cells are aligned in one row in a plane, and are electrically connected in series, the first cell group and the second cell group being electrically connected in series to each other via a current interruption mechanism, and being disposed facing each other, and each cell comprising the first cell group further being disposed facing at least one cell comprising the second cell group.

Description

Battery module and battery system using the same

The present invention relates to a battery module and a battery system using the same.

Battery systems are used to store electricity generated using natural energy, as well as for facility backup power. Conventionally, such a large battery system has been constructed with a lead-acid battery. However, due to recent demands for space saving and lead-free, a large battery system using a lithium ion secondary battery for the battery system. Development is progressing.

There are various types of lithium ion secondary batteries such as a wound type and a laminated type. For example, a laminate-type lithium ion secondary battery is composed of a laminate in which positive and negative electrode plates are alternately laminated, a cell film that accommodates the laminate, an electrolyte filled in the cell film, and the like. Yes. A plurality of such secondary batteries are generally combined and housed in a module case and used as a battery module.

In recent years, battery modules tend to be smaller and larger in capacity. For this reason, the request | requirement with respect to the safety | security of a battery module has become severe. One of the safety test items is a nail penetration test. The acceptance criteria for this test is that no fire or smoke is generated even if a nail is applied to the battery module. In the case of a battery module in which batteries are stacked, when a nail is inserted into the module in parallel with the cell stacking direction, a short-circuit current between the nail and the cell flows continuously. As a result, thermal runaway occurs, and there is a high possibility that dangerous phenomena such as ignition and smoke will occur. For this reason, a mechanism for preventing thermal runaway due to occurrence of a short-circuit current is necessary.

In Patent Document 1, an internal short-circuit detection plate is provided between cells, and when the internal short-circuit detection plates are short-circuited, the conductivity detection unit detects a short-circuit current, and is provided between cells by a signal from the conductivity detection unit. A battery module is disclosed in which a bypass circuit is provided by turning on the relay to prevent abnormal heat generation of the cell.

JP2007-141511

However, in the invention disclosed in Patent Document 1, if a short circuit does not occur up to the internal short circuit detection plate, there is a possibility that thermal runaway cannot be suppressed. In addition, it is necessary to provide a plurality of internal short-circuit detection plates, and further a conductivity detection unit is required, which increases the number of parts and leads to an increase in the size of the battery module. Furthermore, since it is a structure which only provides a bypass circuit, the electric current of a cell cannot be interrupted | blocked completely.

In view of the above problems, an object of the present invention is to provide a battery module that can reliably cut off the current flowing in the battery module no matter what the short circuit occurs.

The battery module according to the present invention includes a first cell group in which at least two or more cells are arranged in a row on a plane and electrically connected in series, and at least two or more cells in a row on a plane. A first cell group and a second cell group electrically connected in series, and the first cell group and the second cell group are electrically connected in series via a current blocking mechanism. And each of the cells constituting the first cell group is arranged opposite to at least one of the cells constituting the second cell group.

According to the present invention, it is an object of the present invention to provide a battery module that can reliably cut off the current flowing in the battery module no matter what the short circuit occurs.

The battery module 200a schematic diagram. (A) The cross-sectional schematic diagram of the battery module 200a, and (b) A partially enlarged view of (a). (A) The perspective view of the battery module 200a, (b) The exploded perspective view of the battery module 200. Schematic of the battery module 202. FIG. The cross-sectional schematic diagram of the battery module 210 which concerns on 2nd embodiment. The cross-sectional schematic diagram of the battery module 220 which concerns on 3rd embodiment. Schematic which concerns on 4th embodiment. Schematic of the battery module 200b. 1 is a schematic diagram of a battery system 300. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a battery module. The battery module 200a includes a cell 101, a fuse 102, a partition plate 103, a bus bar 104, a positive terminal 105a, a negative terminal 105b, a module case 106, and

output terminals

107 and 108. The bus bar 104 that electrically connects the cells is fixed by an electrode fixture (not shown). In the present embodiment, the cell 101 is composed of a laminated lithium ion battery cell. By configuring with laminated lithium ion battery cells, even if a short circuit occurs, even if a large amount of heat is generated instantaneously, it is thin and has good heat dissipation, so that secondary abnormalities due to temperature rise can be prevented. This is preferable because it becomes possible.

The cell 101 is divided into a plurality of cells 101a arranged in one plane and a cell 101b arranged in a plane different from the plane in which the cells 101a are arranged. For convenience of explanation, the first cell group 201a includes a plurality of cells 101a arranged in one plane, and the second cell group includes a plurality of cells 101b arranged in a plane different from the plane in which the cells 101a are arranged. Called 201b. The first cell group 201a and the second cell group 201b are arranged via a partition plate 103 made of metal. Further, at least one cell 101 (b) constituting the second cell group 201b is arranged at a position facing each cell 101 (a) constituting the first cell group 201a. It has become. In such a configuration, the first cell group 201a and the second cell group 201b are electrically connected via the fuse 102, so that a fuse can be reliably connected regardless of which cell is short-circuited. A current loop through 102 is formed, and the fuse 102 can be reliably broken. A more detailed principle will be described with reference to FIG.

FIG. 2A shows a cross-sectional view of the battery module 200a. The cells having the bus bar 104201 positive electrode terminal 105a and the negative electrode terminal 105b are arranged in a line on one plane to constitute the cell group 201. The positive electrode terminal 105 a and the adjacent negative electrode terminal 105 b of each cell are connected in series via the bus bar 104. For this connection, any of a method using a crimping fitting, a welding method, and screwing may be employed. The

cells

101a and 101b are arranged so that the main surfaces of the cells constituting each cell group 105 face each other. What is important here is that each cell 101a constituting the first battery cell group 201a is configured such that the cell 101b constituting the second cell group 201b is always arranged at an opposing position. By arranging in this way, a short-circuit current through the nail and the cell flows through the fuse regardless of where the nail is inserted. Therefore, the fuse 102 can be surely broken and the short-circuit current can be interrupted. For example, as an example, when a short circuit occurs between the

cells

101 a and 101 b at the position shown in FIG. 2B, the short circuit current can follow the current path 202 through the fuse 102, and the fuse 102 can be reliably connected. Can be broken.

Moreover, in this embodiment, since it is not the structure of a battery module in which a plurality of cells 101 constituting the cell group 105 are stacked, a short-circuit current interrupting mechanism is provided between the cells in order to reliably prevent a short circuit. Since there is no need to provide it, the number of parts can be reduced. Further, as a secondary effect of the present embodiment, since a plurality of cells 101 constituting the cell group 105 are not stacked, the heat dissipation of each cell is improved. In addition, although the present Example was set as the structure by which 4 cells are included in one cell group, it cannot be overemphasized that it is applicable to all the cases which arranged 2 cells or more.

Subsequently, the structure of the battery module 200a will be described more specifically with reference to FIG. 3A shows an overall perspective view of the battery module 200a, and FIG. 3B is a diagram with the module cover of the battery module 200a shown in FIG. 3A removed. In this example, the module cover is composed of two types, 110 and 111. The cover 110 corresponds to the outer frame of the module and is made of resin. The heat sink 111 covers the main surface of the cell. It is provided. The heat radiating plate 111 is formed of a member having good heat dissipation. For example, it may be made of a metal such as copper or aluminum, or a resin material having better heat dissipation than the resin constituting the cover 110. By configuring with such a member, even if a short circuit occurs, even if a large amount of heat is generated instantaneously, it is possible to sufficiently dissipate heat, and it is possible to prevent secondary abnormalities due to temperature rise. Become.

Although not shown, a heat sink 111 is also provided on the main surface of the cell 101b constituting the second cell group 201b.

Although the partition plate 103 may be made of either metal or resin, the metal is more likely to release heat generated from the inside of the battery module 200a during charging and discharging. With such a configuration, even if a short circuit occurs and a large amount of heat is generated instantaneously, it is possible to sufficiently dissipate heat and prevent secondary abnormalities due to temperature rise. .

The material of the bus bar 104 may be another metal plate such as aluminum or a copper plate plated. The material of the module case 106 may be resin or metal, but the metal is more likely to release heat generated from the inside of the module during charging and discharging. Therefore, with this configuration, the thermal conductivity is improved not only in the main surface direction of the cell 101 but also in the inter-cell direction to which the bus bar 104 is connected. Therefore, a short circuit occurs temporarily, and a large amount of heat is instantaneously generated. Even if it occurs, it is possible to sufficiently dissipate heat, and it is possible to prevent the occurrence of secondary abnormality due to temperature rise.

In this embodiment, from the viewpoint of downsizing the battery module 200a and improving heat dissipation, the cell 101 is a laminated lithium ion battery cell. However, regardless of the laminated lithium ion battery cell, the cell 101 has a rectangular shape. A type cell may be used.

Specifically, FIG. 4 shows a configuration using a square cell 115. When the square cell 115 is used, the heat dissipation is reduced as compared with the structure of the laminated lithium ion battery cell. Since the battery capacity increases, the battery module can be applied to a larger system.

Even in the case of a square cell, it can be formed by a method similar to the method described in the example of the laminated lithium ion battery cell. Needless to say, the battery is not limited to the lithium ion secondary battery, and may be a nickel hydride battery or a lead storage battery.

As described above, by using the configuration of the present invention as described above, it is possible to provide a battery module that can reliably cut off a short-circuit current while reducing the number of components.

Hereinafter, the second embodiment will be described. In addition, about the structure similar to 1st embodiment, the number similar to the drawing number used in 1st embodiment is used. Specifically, the difference from the first embodiment is that the fuse 102 is used as the current interruption mechanism in the first embodiment, but in this embodiment, the combination of the current sensor 112, the switch 114, and the control circuit 113 is used. Is.

FIG. 5 shows a cross-sectional view of the battery module 210 of the second embodiment. In the present embodiment, a current sensor 112 and a switch 114 are provided between the first cell group 101a and the second cell group 101b. The current information acquired by the current sensor 112 is output to the control circuit 113. The control circuit 113 converts the current sensor 110 into a current value and outputs a signal for turning off the switch 114 when a current of a certain level or more flows.

Here, the current sensor 112 may be a shunt resistor or a Hall sensor. The switch 114 may be a semiconductor switch or a mechanical switch.

In the battery module 210 configured as described above, when a short-circuit current flows between any of the cells, the connection between the first cell group 101a and the second cell group 101b with a current value input in advance to the control circuit. Can be cut off. Therefore, by configuring the circuit to turn off the switch 113 when a minute current at the initial stage of a short circuit is detected, the short circuit current can be eliminated before a complete short circuit occurs, thereby preventing a dangerous phenomenon such as ignition. The safety of the battery module 210 is improved.

Hereinafter, the third embodiment will be described. In addition, about the structure similar to 1st embodiment, the number similar to the drawing number used in 1st embodiment is used. In this embodiment, the difference from the first embodiment is that, in the first embodiment, the battery module 200a is composed of two cell rows, but in this embodiment, it can also be applied to a three-layer battery module. . FIG. 6 shows the structure of the battery module 220 when three layers are stacked. In this embodiment, it has the 1st cell group 221a comprised from the cell 101a, the 2nd cell group 221b comprised from the cell 101b, and the 3rd cell group 221c comprised from the cell 101c. In the case of this embodiment, since it is necessary to provide the fuse 102 between each cell group 221, it is necessary to use a total of two fuses for the battery module 220 alone, and the number of parts increases. Moreover, although it is inferior to 1st embodiment also in the surface of heat dissipation, since the thickness of the battery module 220 becomes thick compared with 1st embodiment, sufficient intensity | strength is ensured even when it is set as a long module. I can do it. Therefore, even when the battery module is elongated, the safety of the battery module can be ensured while ensuring the strength.

Hereinafter, the fourth embodiment will be described. In addition, about the structure similar to 1st embodiment, the number similar to the drawing number used in 1st embodiment is used. This embodiment is different from the first embodiment in that the cells 101 are arranged in the depth direction.

FIG. 7 shows a configuration example of the battery module 230 when the cells 101 are also arranged in the depth direction. In the embodiments so far, a cell in which the positive electrode terminal 105a and the negative electrode terminal 105b are protruded from only one side of the cell 101 is used. A laminated battery cell is used. In addition, as in the first embodiment, the bus bar 104 and the terminal 105 may be connected by any method of using a crimp fitting, a welding method, and screwing.

Note that, similarly to the first embodiment, the cells 101 constituting the first cell group 231a are arranged to face at least one of the cells 101b constituting the second cell group 231b. By adopting such a configuration, it is possible to create a battery module that is not long in only one direction as in the first embodiment but also wide in the depth direction, so it has higher capacity and excellent heat dissipation. Thus, it is possible to provide a battery module that ensures safety.

Hereinafter, the fifth embodiment will be described. In addition, about the structure similar to 1st embodiment, the number similar to the drawing number used in 1st embodiment is used. In this example, an example in which the battery system 300 is configured by assembling the battery module described in the first embodiment will be described.

FIG. 8 shows a battery module 200b in which through holes 150 are provided at the four corners of the battery module 200a in order to improve assembly. The battery system 300 shown in FIG. 9 is created by fixing and fixing the fixing rod 121 to the through hole 150. When the battery system 300 is configured, a gap 122 having a predetermined interval is provided between the battery modules 200b. By providing the gap 123, when the battery generates heat during charging / discharging, the air in the gap is heated to generate an upward air flow, and heat is released outside the battery system. Specifically, this interval is preferably 1 mm or more from the viewpoint of generating ascending air current, and preferably 5 cm or less from the viewpoint of miniaturization. More preferably, it is 6 mm or more and 10 mm or less. By adopting such a configuration, it is possible to reduce the fluid resistance of natural convection and to bring the rising airflow into contact with the surface of the battery module 200b efficiently, so that the cooling efficiency can be improved.

With such a configuration, even if a short circuit occurs and a large amount of heat is generated instantaneously, it becomes possible to dissipate heat sufficiently, and from the viewpoint of the configuration of the battery system, secondary abnormalities due to temperature rise Occurrence can be prevented.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the spirit of the present invention described in the claims. Can be performed. For example, the above-described embodiments are described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. Furthermore, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 100 Battery module 101 Laminated lithium ion battery cell 102 Fuse 103 Partition plate 104 Bus bar 105a Positive electrode terminal 105b Negative electrode terminal

Claims

A first cell group in which at least two or more cells are arranged in a line on a plane and are electrically connected in series;
A second cell group in which at least two or more cells are arranged in a line on a plane and are electrically connected to each other in series,
The first cell group and the second cell group are electrically connected in series with each other through a current interrupting mechanism, and arranged to face each other,
Furthermore, each cell which comprises said 1st cell group is arrange | positioned facing at least 1 of each cell which comprises a 2nd cell group, The battery module characterized by the above-mentioned.
2. The battery module according to claim 1, wherein the current interruption mechanism is a fuse.
2. The battery module according to claim 1, wherein the current interrupt mechanism is a current sensor and a switch, and a battery system using the battery module.
The battery module according to any one of claims 1 to 3,
The battery module, wherein the first cell group and the second cell group are arranged via a partition plate made of metal.
The battery module according to any one of claims 1 to 4,
A battery module, wherein a heat radiating plate is provided on a surface opposite to a surface facing the second cell group in each cell constituting the first cell group.
The battery module according to any one of claims 1 to 5,
The battery module is a laminated lithium ion battery cell.
In the battery system having a plurality of battery modules according to any one of claims 1 to 6,
A battery system, wherein the battery modules are spaced apart from each other by a predetermined distance.
The battery system according to claim 7,
The battery system according to claim 1, wherein the predetermined interval is 6 mm to 10 mm.