Patent Description:
The present application claims priority to <CIT>, in the Republic of Korea.

In recent years, as demand for portable electronic products such as laptops, video cameras, and portable phones has rapidly increased, and the development of electric vehicles, energy storage batteries, robots, satellites, etc. is in full swing, research on repetitive chargeable/dischargeable high-performance secondary batteries is being actively conducted.

Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries have almost no memory effect compared to nickel-based secondary batteries, and thus, are in the spotlight for their advantages of being free to charge and discharge, extremely low self-discharge rate, and high energy density.

These lithium secondary batteries mainly use a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. Also, these lithium secondary batteries include an electrode assembly in which a positive electrode plate and a negative electrode plate to which a positive electrode active material and a negative electrode active material are applied, respectively, are arranged with a separator therebetween, and an exterior for sealing and storing the electrode assembly together with an electrolyte.

Meanwhile, according to the shape of the battery case, lithium secondary batteries may be classified into can-type secondary batteries in which an electrode assembly is embedded in a metal can and pouch-type secondary batteries in which an electrode assembly is embedded in a pouch of an aluminum laminate sheet.

Here, the pouch of the pouch-type secondary battery may be largely divided into a lower sheet and an upper sheet covering the lower sheet. At this time, an electrode assembly formed by stacking and winding a positive electrode, a negative electrode, and a separator is accommodated in the pouch. In addition, after receiving the electrode assembly, the edges of the upper sheet and the lower sheet are sealed by thermal fusion. In addition, an electrode tab drawn out from each electrode may be coupled to the electrode lead, and an insulating film may be added to a portion of the electrode lead in contact with the sealing portion.

In this way, the pouch-type secondary battery may have the flexibility to be configured in various forms. In addition, the pouch-type secondary battery has the advantage of being able to implement a secondary battery of the same capacity with a smaller volume and mass.

The lithium secondary battery is used as a battery module or a battery pack in which multiple battery cells are overlapped or stacked in a state of mounted on their own or to a cartridge to make a dense structure and then electrically connected to each other to provide high voltage and high current.

In this battery pack configuration, one of the most important issues is safety. In particular, when a thermal event occurs in any one battery module among a plurality of battery modules included in the battery pack, propagation of the event to other battery modules needs to be suppressed. If thermal propagation between the battery modules is not properly suppressed, this may lead to thermal events in other battery modules included in the battery pack, causing bigger problems such as ignition or explosion of the battery pack. Moreover, fire or explosion generated in the battery pack may cause great damage to people or property nearby. Therefore, in such a battery pack, a configuration capable of appropriately controlling the aforementioned thermal event is required.

In particular, a control device such as a BMS (Battery Management System) that controls charging and discharging of the battery module using information such as the voltage of each battery cell constituting the battery module and the temperature of the cell assembly may be connected to the battery module. To connect the control device, it is necessary to install a connector that is electrically connected to each battery cell constituting the battery module and also electrically connected to a temperature sensor for measuring the temperature of the cell assembly.

On the other hand, in a conventional battery module, when a thermal event occurs, there is a problem in that thermal propagation occurs between adjacent battery modules since a flame is exposed at a coupling portion where the connector is connected to a module case.

Document <CIT> discloses a battery module capable of suppressing flame through a connector in case of internal ignition of known type.

Document <CIT> discloses an electrical connector assembly of the related art.

The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery module configured to ensure structural stability even when a thermal event occurs, a battery pack, and a vehicle including the same.

However, the technical purpose to be solved by the present disclosure are not limited to the above, and other objects not mentioned herein will be clearly understood by one of ordinary skill in the art from the following disclosure.

In one aspect of the present disclosure, there is provided a battery module as defined in the appended claims.

In another aspect of the present disclosure, there is provided a battery pack including at least one battery module according to the present disclosure.

In another aspect of the present disclosure, there is provided a vehicle including at least one battery pack according to the present disclosure.

According to an embodiment of the present disclosure, the cover of the connector may include a material having strong heat resistance and rigidity. Therefore, it is possible to minimize the discharge of flame generated from one battery module to the outside of the module case. Accordingly, simultaneous ignition between adjacent battery modules may be suppressed.

In addition, according to an embodiment of the present disclosure, blocking of flame emitted from the cell assembly may be performed inside the module case as much as possible.

In addition, according to an embodiment of the present disclosure, simultaneous ignition between a plurality of battery modules may be prevented by minimizing flame transition between the plurality of battery modules.

In addition, various additional effects may be achieved by various embodiments of the present disclosure. Various effects of the present disclosure will be described in detail in each embodiment, or descriptions of effects that can be easily understood by those skilled in the art will be omitted.

<FIG> is a diagram showing a battery module <NUM> according to an embodiment of the present disclosure, <FIG> and <FIG> are diagrams showing a connector <NUM> provided in the battery module <NUM> of <FIG>, and <FIG> is a cross-sectional view in the direction A-A' of <FIG> (in detail, <FIG> is a view showing the cross-section of the battery module <NUM> of <FIG> along the line A-A' with respect to the XY plane).

In the embodiment of the present disclosure, the X-axis direction shown in the drawing may mean the front-back direction of the battery module <NUM> described later, the Y-axis direction may mean the left-right direction of the battery module <NUM> perpendicular to the X-axis direction and the horizontal plane (XY plane), and Z-axis direction may mean the vertical direction perpendicular to both the X-axis direction and the Y-axis direction.

Referring to <FIG>, a battery module <NUM> according to an embodiment of the present disclosure includes a cell assembly <NUM>, a module case <NUM>, and a connector <NUM>.

The cell assembly <NUM> may include at least one battery cell. Here, the battery cell may mean a secondary battery. Such a battery cell may be provided as a pouch-type battery cell, a cylindrical battery cell, or a prismatic battery cell. As an example, the battery cell may be a pouch-type battery cell.

The module case <NUM> accommodates the cell assembly <NUM> therein. To this end, an internal accommodating space for accommodating the cell assembly <NUM> therein may be provided in the module case <NUM>. The module case <NUM> may include a material having strong heat resistance and rigidity.

The connector <NUM> is provided in the module case <NUM>. In addition, the connector <NUM> includes a cover <NUM> configured to block flame discharged from the cell assembly <NUM>. The connector <NUM> may be connected to a control device such as a battery management system (BMS, not shown) that controls charging and discharging of the battery module <NUM> using information such as voltage and temperature of the cell assembly <NUM>. To this end, the connector <NUM> may be electrically connected to the cell assembly <NUM> and electrically connected to a temperature sensor (not shown) for measuring the temperature of the cell assembly <NUM>.

In a general battery module, an event such as thermal runaway may occur in a specific battery module. In this case, a high-temperature and high-pressure venting gas may be generated inside the specific battery module, and when this venting gas meets oxygen, a flame may be generated inside or outside the battery pack.

In addition, the flame generated in the battery module has a high risk of being transferred to another battery module adjacent to the specific battery module, and accordingly, simultaneous ignition of multiple battery modules may occur. On the other hand, the conventional battery module has a problem that thermal propagation occurs between adjacent battery modules since a flame is exposed at a portion where a connector is coupled to a module case.

The battery module <NUM> of the present disclosure may solve the above-described problem by including the connector <NUM> having the cover <NUM>. The cover <NUM> of the connector <NUM> includes a material having strong heat resistance and rigidity, thereby minimizing the discharge of flame generated from one battery module <NUM> to the outside of the module case <NUM>. Accordingly, simultaneous ignition between adjacent battery modules <NUM> may be suppressed.

According to this embodiment of the present disclosure, simultaneous ignition between the plurality of battery modules <NUM> may be prevented by minimizing the flame transition between the plurality of battery modules <NUM>.

Hereinafter, the detailed structure of the aforementioned connector <NUM> will be described in more detail.

Referring back to <FIG>, the cover <NUM> includes a first portion <NUM> and a second portion <NUM>.

The first portion <NUM> is coupled to the outer surface of the module case <NUM>. As an example, the first portion <NUM> may include a liquid crystal polymer (LCP) material. The melting point of the liquid crystal polymer may be approximately <NUM>.

The second portion <NUM> is coupled to the inner surface of the module case <NUM>. As an example, the second portion <NUM> may include a ceramic or aluminum (Al) material. In addition, a heat resistant coating (not shown) may be applied to the outer surface of the second portion <NUM>. The melting point of this heat-resistant coating may be approximately <NUM>,<NUM> or higher.

Also, a part of the module case <NUM> is disposed between the first portion <NUM> and the second portion <NUM>. That is, the cover <NUM> of the connector <NUM> may be configured in a form coupled to the outer surface and the inner surface of the module case <NUM> with the module case <NUM> interposed therebetween.

According to this embodiment of the present disclosure, during thermal runaway of the battery module <NUM>, the flame emitted from the cell assembly <NUM> may be primarily blocked through a part of the cover <NUM> coupled to the inner surface of the module case <NUM>. In addition, secondarily, the flame may be blocked through the inner surface of the module case <NUM>.

Accordingly, simultaneous ignition between adjacent battery modules <NUM> may be effectively suppressed.

<FIG> is a diagram showing the state of the battery module <NUM> of <FIG> during thermal runaway. At this time, the flame to be described later in <FIG> will be denoted by the reference sign 'F'.

Referring to <FIG>, the second portion <NUM> includes a material having higher heat resistance than the first portion <NUM>.

That is, the shape of the second portion <NUM> may be maintained without being damaged even in a relatively high temperature environment. Therefore, the second portion <NUM> may not be melted even if the flame discharged from the cell assembly <NUM> contacts the second portion <NUM>. In addition, the second portion <NUM> may minimize flame transfer to the first portion <NUM> disposed on the opposite side with the module case <NUM> interposed therebetween.

Accordingly, blocking of the flame discharged from the cell assembly <NUM> may be performed inside the module case <NUM> as much as possible.

Referring to <FIG>, the connector <NUM> may further include a heat blocking member <NUM>.

The heat blocking member <NUM> may be provided on a side surface of the second portion <NUM> facing the cell assembly <NUM>. As an example, the heat blocking member <NUM> may include a silicon ceramic potting material. That is, the heat blocking member <NUM> may include a material with high resistance to flame. The melting point of the heat blocking member <NUM> may be approximately <NUM>,<NUM> or higher.

Meanwhile, the heat blocking member <NUM> may directly contact the flame discharged from the cell assembly <NUM>. In particular, the heat blocking member <NUM> may minimize the transfer of the flame discharged from the cell assembly <NUM> to the first portion <NUM>.

According to this embodiment, the flame may be blocked as much as possible inside the module case <NUM>. Accordingly, simultaneous ignition between adjacent battery modules <NUM> may be suppressed as much as possible.

Referring to <FIG>, the second portion <NUM> may include a protruding portion 314a.

The protruding portion 314a may protrude from a side surface of the second portion <NUM> facing the cell assembly <NUM>. Also, the protruding portion 314a may be configured to surround an edge of the heat blocking member <NUM>.

Meanwhile, the flame discharged from the cell assembly <NUM> may collide with the inner surface of the protruding portion 314a. Accordingly, the protruding portion 314a may guide the flow of the flame discharged from the cell assembly <NUM> toward the heat blocking member <NUM>.

According to this embodiment, the flow of the flame may be induced toward the heat blocking member <NUM>, which has higher heat resistance than the cover <NUM> of the connector <NUM>, so that the emission of the flame to the outside of the module case <NUM> may be more reliably suppressed.

Referring back to <FIG>, the connector <NUM> may further include a sealing portion <NUM>.

The sealing portion <NUM> may be configured to seal a gap between the first portion <NUM> and the module case <NUM>. As an example, the sealing portion <NUM> may include a graphite sheet (carbon sheet) material. The melting point of the sealing portion <NUM> may be approximately <NUM>,<NUM> or higher.

In addition, the sealing portion <NUM> may be coupled in a form fitted to the edge of the first portion <NUM>.

In particular, the sealing portion <NUM> may include a material having higher heat resistance than the second portion <NUM>. Accordingly, external exposure of the flame discharged from the cell assembly <NUM> may be prevented more reliably.

Also, according to this embodiment, it is possible to prevent outside air from being introduced into the module case <NUM> through the gap between the first portion <NUM> and the module case <NUM> even in a high-temperature environment. In addition, it is possible to prevent flame from being discharged to the outside of the module case <NUM> through the gap between the first portion <NUM> and the module case <NUM>.

In addition, the sealing portion <NUM> may be configured to surround the edge of the first portion <NUM> facing the module case <NUM>. Specifically, the sealing portion <NUM> may be configured to surround the edge of the first portion <NUM> facing the module case <NUM> so as to come into surface contact with the outer surface of the module case <NUM>.

According to this embodiment, the sealing area and the flame blocking area through the sealing portion <NUM> may be further increased. Accordingly, inflow of outside air into the module case <NUM> and simultaneous ignition between adjacent battery modules <NUM> may be more reliably suppressed.

Meanwhile, the connector <NUM> may further include at least one terminal <NUM>. This terminal <NUM> may be provided in the cover <NUM>. As an example, the terminal <NUM> may include a copper (Cu) material. The melting point of this terminal <NUM> may be approximately <NUM>,<NUM>.

In addition, one end of the terminal <NUM> may be exposed to the outside of the cover <NUM> and connected to the above-described control device. Also, the other end of the terminal <NUM> may be electrically connected to the cell assembly <NUM>. In one embodiment, the other end of the terminal <NUM> may be electrically connected to the cell assembly <NUM> through a separate connection line L. However, it is not limited thereto, and the other end of the terminal <NUM> may be directly connected to the cell assembly <NUM>.

Although not shown, in the module case <NUM>, a venting hole may be provided in a portion other than the area where the connector <NUM> is provided. Accordingly, venting gas generated during thermal runaway of the cell assembly <NUM> may be quickly discharged to the outside of the module case <NUM> through the venting hole.

Referring again to <FIG>, the connector <NUM> may further include a coupling member B.

The coupling member B may be configured to penetrate the module case <NUM> and couple the first portion <NUM> and the second portion <NUM> to each other. As an example, the coupling member B may be a wrench bolt, but is not limited thereto.

According to this embodiment, the first portion <NUM> and the second portion <NUM> may come into close contact with the outer surface and the inner surface of the module case <NUM>, respectively. Accordingly, the emission of flame to the outside of the module case <NUM> may be more stably suppressed.

<FIG> is a diagram showing a battery pack <NUM> including the battery module <NUM> of <FIG>.

Referring to <FIG>, a battery pack <NUM> according to an embodiment of the present disclosure may include at least one battery module <NUM> described above. Although not shown in detail, the battery pack <NUM> may further include various devices for controlling charging and discharging of the battery module <NUM>. As an example, the battery pack <NUM> may further include a battery management system (BMS), a current sensor, and a fuse.

As described above, in the battery module <NUM> of the present disclosure, exposure of flame to the outside at a portion where the connector <NUM> is coupled to the module case <NUM> may be minimized. Accordingly, simultaneous ignition between adjacent battery modules <NUM> may be suppressed.

In summary, according to the above embodiment of the present disclosure, it is possible to suppress the ignition factor of the battery pack <NUM> including the plurality of battery modules <NUM> and to enhance the structural stability of the battery pack <NUM>.

<FIG> and <FIG> are diagrams showing a battery module <NUM> according to another embodiment of the present disclosure. At this time, the flame to be described later in <FIG> will be denoted with the reference sign 'F'.

Since the battery module <NUM> according to this embodiment is similar to the battery module <NUM> of the previous embodiment, redundant description of components substantially the same as or similar to those of the previous embodiment will be omitted, and the following will focus on differences from the previous embodiment.

Referring to <FIG> and <FIG>, in the battery module <NUM>, the connector <NUM> may further include a bent portion D.

The bent portion D may be formed by bending from the protruding portion 314a toward the cell assembly <NUM>. Specifically, the bent portion D may be bent radially outward toward the cell assembly <NUM>. As an example, the bent portion D may be provided as a pair in the vertical direction (Z-axis direction), but is not limited thereto.

This bent portion D may further weaken the flow of the flame discharged from the cell assembly <NUM>. That is, as shown in <FIG>, the flame emitted from the cell assembly <NUM> may be directed toward the heat blocking member <NUM> while colliding with the side surface of the bent portion D facing the cell assembly <NUM>. In this case, exposure of the flame to the outside of the module case <NUM> may be blocked more reliably.

According to the battery module <NUM> according to this embodiment, the flow of the flame discharged from the cell assembly <NUM> may be weakened, and simultaneous ignition between adjacent battery modules <NUM> may be more minimized.

<FIG> and <FIG> are diagrams showing a battery module <NUM> according to still another embodiment of the present disclosure. At this time, the flame to be described later in <FIG> will be denoted with the reference sign 'F'.

Referring to <FIG> and <FIG>, in the battery module <NUM>, the side of the module case <NUM> including the connector <NUM> may be inclined downward.

Accordingly, the connector <NUM> may also be provided in the module case <NUM> in a downwardly inclined shape.

That is, in the battery module <NUM> according to this embodiment, the flame discharged from the cell assembly <NUM> may collide with the second portion <NUM> configured in a downwardly inclined shape, the heat blocking member <NUM>, and the like, so that the flow of the flame may be bent downward.

In the battery module <NUM> according to this embodiment, the flow of the flame discharged from the cell assembly <NUM> may be weakened through the downwardly inclined arrangement of the connector <NUM>, and simultaneous ignition between adjacent battery modules <NUM> may be further minimized.

Meanwhile, the battery pack <NUM> according to the present disclosure may be applied to a vehicle such as an electric vehicle. That is, the vehicle according to the present disclosure may include at least one battery pack <NUM> according to the present disclosure.

Claim 1:
A battery module (<NUM>) comprising:
a cell assembly (<NUM>);
a module case (<NUM>) for accommodating the cell assembly (<NUM>) therein; and
a connector (<NUM>) provided in the module case (<NUM>) and having a cover (<NUM>) configured to block flame discharged from the cell assembly;
wherein the cover includes:
a first portion (<NUM>) coupled to an outer surface of the module case (<NUM>); and
a second portion (<NUM>) coupled to an inner surface of the module case (<NUM>),
wherein a part of the module case (<NUM>) is disposed between the first portion (<NUM>) and the second portion (<NUM>),
wherein the second portion (<NUM>) includes a material with higher heat resistance than the first portion (<NUM>), and
wherein the second portion (<NUM>) is disposed on the opposite side with the module case (<NUM>) interposed therebetween from the first portion (<NUM>).