KR20210108269A - Battery module and battery pack including the same - Google Patents

Abstract

According to an embodiment of the present invention, a battery module comprises: a module frame including a lower plate and sidewalls forming an inner space; a battery cell stack in which a plurality of battery cells are stacked adjacent to each other in parallel, wherein the battery cell stack is located in the inner space of the module frame; a plurality of electrode leads individually protruding from the battery cell included in the battery cell stack; a bus bar frame covering at least one side of the battery cell stack from which the plurality of electrode leads protrude; and a first leak liquid detection sensor disposed on one surface of the bus bar frame facing the battery cell stack.

Description

A battery module and a battery pack including the same

The present invention relates to a battery module and a battery pack including the same, and more particularly, to a battery module with improved safety and a battery pack including the same.

As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. Accordingly, a lot of research has been done on secondary batteries that can meet various needs.

Secondary batteries are attracting a lot of attention as an energy source for power devices such as electric magnetrons, electric vehicles, and hybrid electric vehicles, as well as mobile devices such as cell phones, digital cameras, and notebook computers.

A small battery pack in which a single battery cell is packed is used for small devices such as mobile phones and cameras, but a battery pack in which two or more battery cells are connected in parallel and/or in series is used in mid- to large-sized devices such as notebook computers and electric vehicles. Packed medium or large battery packs are used. Accordingly, the number of battery cells included in the battery pack may be variously set according to a required output voltage or charge/discharge capacity.

On the other hand, when configuring a battery pack by connecting a plurality of battery cells in series/parallel, a battery module including at least one battery cell is first configured, and other components are added using the at least one battery module to add other components to the battery pack. The general way to configure The number of battery modules included in the battery pack or the number of battery cells included in the battery module may be variously set according to a required output voltage or charge/discharge capacity. The battery module set in this way is configured to include a plurality of battery cells stacked together and a bus bar assembly electrically connecting electrode leads of the plurality of battery cells.

In the case of such a battery module, as the required battery capacity increases, the demand for stability increases, and in particular, it is necessary to quickly detect a failure mode of the battery module and respond appropriately. However, especially in the case of a failure of electrolyte leakage that may cause a low voltage due to voltage drop, there is a problem in that even if leakage occurs, there is a problem in that a means is not provided for quickly detecting the leakage.

Embodiments of the present invention, it is an object of the present invention to provide a battery module and a battery pack including the same, in which the safety is improved by quickly detecting electrolyte leakage even by a simple means.

However, the problems to be solved by the embodiments of the present invention are not limited to the above problems and may be variously expanded within the scope of the technical idea included in the present invention.

A battery module according to an embodiment of the present invention includes a module frame including a lower plate and a sidewall forming an inner space, located in the inner space of the module frame, and a plurality of battery cells are stacked adjacent to each other in parallel A battery cell stack, a plurality of electrode leads each protruding from the battery cells included in the battery cell stack, a bus bar frame covering at least one side of the battery cell stack from which the plurality of electrode leads protrude, and the battery and a first leak detection sensor disposed on one surface of the bus bar frame facing the cell stack.

The bus bar frame may include a plurality of slits into which the plurality of electrode leads are inserted, and the first leak detection sensor may be disposed around the slits.

The first leak detection sensor may be a film-type sensor.

The film-type sensor may include an adhesive layer, a circuit film disposed on the adhesive layer, and an insulating coating layer disposed on the circuit film.

The circuit film may include a substrate disposed on the adhesive layer, and an electrode layer disposed on the substrate.

The insulating coating layer may be a material that reacts with an organic solvent and melts.

When the insulating coating layer is melted by the organic solvent, the electrode layer may be exposed to the organic solvent, resulting in a disconnection or a change in electrical resistance.

The battery cell is a pouch-type battery cell in which an electrode assembly and an electrolyte are accommodated inside the pouch, and the organic solvent may be a part of the electrolyte.

The battery module may further include a second leak detection sensor positioned between the lower plate and the battery cell stack and having the same structure as the first leak detection sensor.

The battery module may further include a thermally conductive resin layer disposed between the lower plate and the second leak detection sensor.

A battery pack according to another embodiment of the present invention may include the at least one battery module, and a pack case for packaging the at least one battery module.

A device according to another embodiment of the present invention may include the above-described at least one battery pack.

According to the embodiments of the present invention, by appropriately applying a leak detection sensor, which is a film-type sensor, in the battery module, it is possible to quickly detect the leakage of the electrolyte, thereby improving the safety of the battery module.

1 is a perspective view of a battery module according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of the battery module of FIG. 1 .
3 is a diagram schematically illustrating an inner surface of a bus bar frame included in the battery module of FIG. 2 .
4 is a perspective view of a battery cell included in the battery module of FIG. 2 .
FIG. 5 is a cross-sectional view illustrating a detection principle of a leak detection sensor included in the battery module of FIG. 2 .
6 is an exploded perspective view of a battery module according to another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, various embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are given to the same or similar elements throughout the specification.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar. In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. And in the drawings, for convenience of description, the thickness of some layers and regions are exaggerated.

Also, when a part of a layer, film, region, plate, etc. is said to be “on” or “on” another part, it includes not only cases where it is “directly on” another part, but also cases where another part is in between. . Conversely, when we say that a part is "just above" another part, we mean that there is no other part in the middle. In addition, to be "on" or "on" the reference portion means to be located above or below the reference portion, and to necessarily mean to be located "on" or "on" in the direction opposite to gravity no.

In addition, throughout the specification, when a part "includes" a certain component, this means that other components may be further included, rather than excluding other components, unless otherwise stated.

In addition, throughout the specification, when referring to "planar", it means when the target part is viewed from above, and "in cross-section" means when viewed from the side when a cross-section of the target part is vertically cut.

1 is a schematic perspective view of a battery module according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of the battery module of FIG. 1 , and FIG. 3 is an inner surface of a busbar frame included in the battery module of FIG. 2 . It is a diagram schematically shown.

1 to 3 , the battery module 100 according to an embodiment of the present invention accommodates a battery cell stack 200 in which a plurality of battery cells 110 are stacked, and a battery cell stack 200 . and a pair of bus bar frames 700 covering both sides of the module frame 300 and the battery cell stack 200 . At this time, the first leak detection sensor 900 is disposed inside the at least one bus bar frame 700 , that is, on one surface of the side opposite to the battery cell stack 200 .

The module frame 300 may have an open front (x-axis direction) and back (x-axis direction), and the end plate 600 covers the open front and rear surfaces of the module frame 300 , respectively. can The module frame 300 and the end plate 600 preferably have a predetermined strength to protect the battery cell stack 200 and other electrical components from external impact, and for this purpose, include a metal material, particularly aluminum. can

On the other hand, the module frame 300 according to this embodiment may include a U-shaped frame 400 with an open upper surface (z-axis direction) and an upper plate 500 covering the open upper surface of the U-shaped frame 400 . can The U-shaped frame 400 and the upper plate 500 may be joined to each other through welding, but the joining method is not limited thereto, and may be implemented through various embodiments. In addition, the shape of the module frame 300 is not limited thereto, and may have the form of a mono frame in which a U-shaped frame and an upper plate are integrally formed, and is not particularly limited.

The U-shaped frame 400 may include a bottom portion 310 and two side portions 320 extending in the upper direction (Z-axis direction) from opposite sides of the bottom portion 310, and the two side portions ( The distance between the 320 is preferably equal to the width of the upper plate 500 .

In addition, a thermally conductive resin layer 810 capable of dissipating heat generated from the battery cell stack 200 to the outside may be disposed on the bottom of the U-shaped frame 400 . In this case, the thermally conductive resin layer 810 may be disposed to be spaced apart from each other on both sides with an insulating layer 820 therebetween in order to appropriately adjust the amount of the thermal conductive resin layer 810 applied therebetween. The thermally conductive resin layer 810 is formed by applying a thermally conductive resin to the bottom 310, and the thermally conductive resin may include a thermally conductive adhesive material, specifically, a silicone material, It may include at least one of a urethane material and an acrylic material. The thermally conductive resin may serve to fix one or more battery cells 110 constituting the battery cell stack 200 by being liquid during application but solidified after application. In addition, it is possible to prevent overheating of the battery module 100 by quickly transferring the heat generated in the battery cell 110 toward the lower surface of the battery module 100 due to excellent thermal conductivity.

Meanwhile, referring to FIG. 2 , a recessed groove 340 may be formed without applying a thermal conductive resin so that the protrusion 110p of the battery cell 110 shown in FIG. 4 can be mounted.

A bus bar 710 connecting the electrode leads 150 (shown in FIG. 4 ) of each battery cell 110 is mounted on the bus bar frame 700 .

Specifically, the bus bar frame 700 may be formed on the front surface (x-axis direction) and the rear surface (the opposite direction of the x-axis) of the battery cell stack 200 according to the protruding direction of the electrode lead 150 , respectively. The electrode leads 150 of the battery cell 110 may be bent after passing through a slit 720 (shown in FIG. 3 ) formed in the bus bar frame 700 to be connected to the bus bar 710 . Since the end plate 600 is in contact with the module frame 300 , various electrical components mounted on the bus bar frame 700 including the bus bar 710 can be protected from external impacts and the like.

On the other hand, the state of the battery cell 110 included in the battery cell stack 200 is shown in FIG. 4 is a perspective view of the battery cell 110 included in the battery module of FIG. 2 .

Referring to FIG. 4 , the battery cell 110 is preferably a pouch-type battery cell. For example, the battery cell 110 according to the present embodiment has a structure in which two electrode leads 150 face each other and protrude from one end 114 and the other end 114b of the battery body 113, respectively. has In more detail, the electrode lead 150 is connected to the electrode assembly (not shown) and protrudes from the electrode assembly (not shown) to the outside of the battery cell 110 .

Meanwhile, in the battery cell 110 , both ends 114a and 114b of the battery case 114 and one side 114c connecting them are adhered in a state in which an electrode assembly (not shown) is accommodated in the battery case 114 . It can be manufactured by In other words, the battery cell 110 according to the present embodiment has a total of three sealing parts 114sa, 114sb, 114sc, and the sealing parts 114sa, 114sb, 114sc are sealed by a method such as thermal fusion. , the other one side may be formed of a connection part 115 . In addition, the connection part 115 may extend long along one edge of the battery cell 110 , and a protrusion 110p of the battery cell 110 called a bat-ear is formed at an end of the connection part 115 . can be

Referring back to FIG. 2 , the battery cells 110 of FIG. 4 may be stacked along the y-axis direction to form the battery cell stack 200 . Accordingly, the electrode leads 150 of the plurality of battery cells 110 may protrude toward the front (x-axis direction) and the rear surface (the opposite direction of the x-axis), respectively.

In this embodiment, as shown in FIG. 2 , a plurality of first leak detection sensors 900 are disposed on one surface of the bus bar frame 700 where the bus bar frame 700 and the battery cell stack 200 face each other. can be placed. That is, the inner surface of each of the bus bar frames 700 facing the front and rear surfaces of which the electrode leads 150 of the plurality of battery cells 110 protrude (or the inner surface of at least one of the bus bar frames 700 ). The first leak detection sensor 900 may be formed by attaching the film-type sensor to the .

At this time, the first leak detection sensor 900 may be attached along the periphery of the slit 720 formed in the bus bar frame 700 within a range that does not interfere with the slit 720 . Accordingly, the electrolyte leakage from the sealing parts 114sa and 114sb around the electrode lead 150 inserted through the slit 720 can be detected more quickly. That is, as shown in FIG. 4 , in the portion where the electrode lead 150 protrudes in the pouch battery cell 110 , the sealing parts 114sa and 114sb inevitably overlap the electrode lead 150 . In this part, the bonding force is somewhat weak compared to other parts where pouches are joined, so the possibility of electrolyte leakage increases. Therefore, disposing the first leak detection sensor 900 around the slit 720 into which the electrode lead 150 is inserted is to place the first leak detection sensor 900 closest to the place where the electrolyte leak is high, so that the electrolyte leak can be more quickly can detect In FIG. 3 , only the arrangement of the first leak detection sensor 900 along the longitudinal direction of the slit 720 is exemplified, but the first leak detection sensor 900 is a film-type sensor and there is no restriction on its arrangement, so the slit As long as it does not interfere with the 720 , it may be disposed on the slit 720 and the lower portion.

Meanwhile, the cross-sectional structure of the film-type sensor that can be used as the first leak detection sensor 900 is shown in FIG. 5 . FIG. 5 is a cross-sectional view illustrating a detection principle of a leak detection sensor included in the battery module of FIG. 2 .

5, the film-type sensor usable as the first leak detection sensor 900 is an adhesive layer 910 for attaching to an object such as a bus bar frame 700, and the adhesive layer 910 is disposed on The circuit film 920 may include an insulating coating layer 930 disposed on the circuit film 920 to protect the circuit provided in the circuit film 920 . Also, the circuit film 920 may include a substrate 921 disposed on the adhesive layer 910 and an electrode layer 922 disposed on the substrate 921 to configure a circuit.

The first leak detection sensor 900 having such a structure is a sensor capable of detecting acids, alkalis, organic solvents, etc. except for water. That is, as shown in FIG. 5, when the organic solvent leaks on the surface of the sensor 900, the insulating coating layer 930 reacts with the organic solvent and melts, and the electrode layer 922 is exposed to the organic solvent, so that the circuit Disconnection occurs, or an organic solvent penetrates into the circuit, and the electrical resistance value changes at the leak point. Accordingly, since the current sensing value appears different from the previous state in which there was no leakage, a leak detection controller (not shown) included in a battery management system (BMS) may detect a liquid leakage situation.

In particular, in the battery module 100 as in the present embodiment, when the electrolyte leaks from the pouch-type battery cell in which the electrode assembly and the electrolyte are accommodated in the pouch, the organic solvent contained therein is the first leak detection sensor 900 . ) of the insulating coating layer 930 is melted so that leakage of the electrolyte can be detected. According to this structure, it is possible to detect electrolyte leakage simply by arranging the first leak detection sensor 900, which is a film-type sensor, thereby improving safety, and the sensor does not detect water but detects only organic solvents. Therefore, it is possible to accurately detect only the leakage of the electrolyte without reacting to the penetration of moisture or the like.

Hereinafter, a battery module 100 according to another embodiment of the present invention will be described with reference to FIG. 6 .

6 is an exploded perspective view of a battery module according to another embodiment of the present invention.

In this embodiment, as compared with the previous embodiment, a second leak detection sensor 901 positioned between the lower plate 400 and the battery cell stack 200 is further included. At this time, since the configuration other than the present difference overlaps with the above-described content, detailed description thereof will be omitted.

That is, the second leak detection sensor 901 may be disposed between the bottom surface 310 of the lower plate 400 and the battery cell stack 200 , and more specifically, applied to the bottom surface 310 . A second leak detection sensor 901 may be disposed between the thermally conductive resin layer 810 and the battery cell stack 200 . The second leak detection sensor 901 has the same structure as the first leak detection sensor 900 , and thus is a film-type sensor. By attaching the strip-type film-type sensor on the thermal conductive resin layer 810 , can be formed.

According to this configuration, in addition to the leak detection sensor disposed around the electrode lead 150 , since an additional leak detection sensor is further provided at the bottom of the battery module 100 , the electrolyte solution in a portion other than the electrode lead 150 . Even if a leak occurs, it is possible to quickly detect the electrolyte flowing to the bottom. Accordingly, it is possible to improve the safety of the battery module 100 by enabling more rapid detection of electrolyte leakage.

One or more battery modules according to the present embodiment described above may be mounted together with various control and protection systems such as a battery management system (BMS) and a cooling system to form a battery pack.

The above-described battery module and battery pack including the same may be applied to various devices. These devices can be applied to transportation means such as electric bicycles, electric vehicles, hybrid vehicles, etc., but the present invention is not limited thereto and can be applied to various devices that can use a battery module and a battery pack including the same. It belongs to the scope of the invention.

Although the preferred embodiment of the present invention has been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims are also provided. is within the scope of the

100: battery module
110: battery cell
200: battery cell stack
300: module frame
310: bottom
600: end plate
700: bus bar frame
710: bus bar
720: slit
900: first leak detection sensor
901: second leak detection sensor

Claims (12)

a module frame including a lower plate and sidewalls defining an interior space;
A battery cell stack in which a plurality of battery cells are stacked adjacent to each other in parallel, located in the inner space of the module frame,
a plurality of electrode leads each protruding from the battery cells included in the battery cell stack;
a bus bar frame covering at least one side of the battery cell stack from which the plurality of electrode leads protrude; and
A battery module including a first leak detection sensor disposed on one surface of the bus bar frame facing the battery cell stack. In claim 1,
The bus bar frame includes a plurality of slits into which the plurality of electrode leads are inserted, and the first leak detection sensor is disposed around the slits. In claim 1,
The first leak detection sensor is a film-type sensor battery module. In claim 3,
The film-type sensor is a battery module comprising an adhesive layer, a circuit film disposed on the adhesive layer, and an insulating coating layer disposed on the circuit film. In claim 4,
The circuit film is a battery module including a substrate disposed on the adhesive layer, and an electrode layer disposed on the substrate. In claim 5,
The insulating coating layer is a battery module of a material that reacts with an organic solvent and melts. In claim 6,
When the insulating coating layer is melted by the organic solvent, the electrode layer is exposed to the organic solvent to cause a disconnection or a change in electrical resistance value. In claim 7,
The battery cell is a pouch-type battery cell in which an electrode assembly and an electrolyte are accommodated inside the pouch,
The organic solvent is a part of the electrolyte battery module. In claim 1,
The battery module further comprising a second leak detection sensor positioned between the lower plate and the battery cell stack and having the same structure as the first leak detection sensor. In claim 9,
The battery module further comprising a thermally conductive resin layer disposed between the lower plate and the second leak detection sensor. At least one battery module according to any one of claims 1 to 10, and
A pack case for packaging the at least one battery module
A battery pack comprising a. A device comprising at least one battery pack according to claim 11 .

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