Patent Description:
The present disclosure relates to a battery pack, a vehicle including the battery pack, and a control method of the battery pack.

The secondary battery is drawing attention as a new energy source for enhancing energy efficiency and environment friendliness in that the use of fossil fuels can be reduced greatly and no byproduct is generated during energy consumption.

Meanwhile, when a plurality of battery cells are connected in series or in parallel to configure a battery pack, it is common to configure a battery module composed of at least one battery cell first, and then configure a battery pack by using at least one battery module and adding other components.

The conventional battery pack includes battery modules, each having a plurality of battery cells. Here, when an abnormal situation occurs due to expansion of a battery cell in any one battery module in an overheating situation over a predetermined temperature, if the abnormal situation is not quickly solved, thermal runaway may propagate to neighboring battery modules, which may lead to explosion or the like of the battery pack and thus cause a great danger to the user.

Therefore, when an abnormal situation occurs at a specific battery cell of the battery module in an overheating situation over a predetermined temperature, it is necessary to promptly solve the abnormal situation. In particular, it is necessary to secure safety by preventing propagation of the thermal runaway before the thermal runaway leads to neighboring the surrounding battery modules to cause explosion or fire of the battery pack.

Further prior art is described in <CIT>, <CIT>, <CIT>, and <CIT>.

The present disclosure is directed to providing a battery pack, which may improve the safety by preventing thermal runaway, a vehicle including the battery pack, and a control method of the battery pack.

In one aspect of the present disclosure, there is provided a battery pack provided in a vehicle, comprising: at least one battery module having at least one battery cell; a relay unit configured to connect the at least one battery module to a motor unit of the vehicle; and a control unit connected to the relay unit and the motor unit to control the relay unit and the motor unit, wherein when a temperature of the at least one battery cell of the at least one battery module rises over a predetermined temperature, the control unit shifts a gear of the vehicle to a neutral mode and closes a switch of the relay unit so that the motor unit idles.

When the temperature of the at least one battery cell of the at least one battery module rises over the predetermined temperature, the control unit may be designed to control the warning unit to send a danger signal to the driver of the vehicle.

The control unit may be designed to shift a gear of the vehicle to a neutral mode together with operating the warning unit so that the motor unit idles.

The control unit may be designed to shift a gear of the vehicle to a neutral mode so that the motor unit idles after a preset predetermined time passes from the operation of the warning unit.

The battery pack may further comprise at least one external resistor unit configured to connect the relay unit and the motor unit.

In addition, the present disclosure provides a control method of a battery pack provided in a vehicle comprising a battery pack as described above, comprising: shifting a gear of the vehicle to a neutral mode, when a temperature of at least one battery cell of at least one battery module rises over a predetermined temperature; closing the switch of the relay unit connected to the at least one battery module over the predetermined temperature; and allowing the motor unit of the vehicle connected to the relay unit to idle according to an operation of the relay unit.

Moreover, the present disclosure provides a vehicle comprising: at least one battery pack according to the above embodiments.

According to various embodiments as above, it is possible to provide a battery pack, which may improve the safety by preventing thermal runaway, a vehicle including the battery pack, and a control method of the battery pack.

<FIG> is a diagram for illustrating a vehicle according to an embodiment of the present disclosure, and <FIG> is a diagram for illustrating a battery pack of the vehicle of <FIG>.

Referring to <FIG> and <FIG>, a vehicle <NUM> may be an electric vehicle or a hybrid electric vehicle, which includes a secondary battery as an energy source. Hereinafter, in this embodiment, the vehicle <NUM> will be described as an electric vehicle.

The vehicle <NUM> includes a body <NUM>, a motor unit <NUM>, a gear <NUM>, an alarm unit <NUM> and a battery pack <NUM>.

The body <NUM> forms an appearance of the vehicle <NUM> and has a driving space and a riding space for a user such as a driver, and various components of the vehicle <NUM> may be accommodated in or mounted to the body <NUM>.

The motor unit <NUM> is for operating the vehicle <NUM> and the like, and is provided to the body <NUM>. The motor unit <NUM> is connected to a gear <NUM> and a battery pack <NUM>, explained later.

The gear <NUM> is connected to the motor unit <NUM> and may be shifted according to manipulation of a driver. For example, the gear <NUM> may be shifted to a running mode, a neutral mode, a reverse mode or a parking mode according to the driver's manipulation while the vehicle is running or stopped.

The alarm unit <NUM> is connected to warning unit <NUM> of the battery pack <NUM>, explained later, and is provided at a position that may be recognized by the driver when a danger situation occurs at the body <NUM>.

The alarm unit <NUM> may be provided in the form of a display unit that provides visual information to the user to inform occurrence of the danger situation, a sound unit that provides auditory information to the user, or an audiovisual unit that provides both visual information and auditory information. The alarm unit <NUM> may be provided in other forms as well, without being limited to the above, as long as the user may be informed of the occurrence of the danger situation.

The battery pack <NUM> is provided to the body <NUM> as an energy source of the vehicle <NUM>. The battery pack <NUM> provides energy for operating the motor unit <NUM>.

The battery pack <NUM> includes at least one battery module <NUM>, a pack case <NUM>, a relay unit <NUM>, a warning unit <NUM>, and a control unit <NUM>.

At least one battery module <NUM> or a plurality of battery modules <NUM> may be provided. Hereinafter, in this embodiment, it will be described that a plurality of battery modules <NUM> are provided. The plurality of battery modules <NUM> are electrically connected to each other and are provided inside the pack case <NUM>, explained later.

Each of the plurality of battery modules <NUM> includes at least one battery cell <NUM>.

The battery cell <NUM> is a secondary battery, and may be provided as a pouch-type secondary battery, a rectangular secondary battery, or a cylindrical secondary battery. Hereinafter, in this embodiment, the battery cell <NUM> will be described as a pouch-type secondary battery.

At least one battery cell <NUM> or a plurality of battery cells <NUM> may be provided. Hereinafter, in this embodiment, it will be described that a plurality of battery cells <NUM> are provided and stacked on each other so as to be electrically connected to each other.

The pack case <NUM> is mounted to the body <NUM>, and accommodates the plurality of battery modules <NUM>, the relay unit <NUM>, the warning unit <NUM> and the control unit <NUM>, explained later.

The relay unit <NUM> is provided to the pack case <NUM>, and is electrically connected to the control unit <NUM>, explained later. The relay unit <NUM> connects the at least one battery module <NUM>, or the plurality of battery modules <NUM> in this embodiment, to the motor unit <NUM> of the vehicle <NUM>.

The warning unit <NUM> is provided to the pack case <NUM>. The warning unit <NUM> is electrically connected to the control unit <NUM>, explained later.

The warning unit <NUM> is connected to the alarm unit <NUM> of the vehicle <NUM>, and when a danger situation occurs, the warning unit <NUM> provides the danger information or the like to the alarm unit <NUM> to guide the operation of the alarm unit <NUM>.

The control unit <NUM> is provided to the pack case <NUM>, and is electrically connected to the motor unit <NUM>, the gear <NUM> and the alarm unit <NUM> of the vehicle <NUM> to control operations of the motor unit <NUM>, the gear <NUM> and the alarm unit <NUM>.

The control unit <NUM> is electrically connected to the battery module <NUM>, the relay unit <NUM> and the warning unit <NUM> to control operations of the battery module <NUM>, the relay unit <NUM> and the warning unit <NUM>.

Hereinafter, the detailed control operation of the control unit <NUM> according to this embodiment will be described in more detail.

If a temperature of the at least one battery cell <NUM> of the at least one battery module <NUM> rises over a predetermined temperature, the control unit <NUM> operates the relay unit <NUM> so that the motor unit <NUM> idles.

Specifically, if the temperature of the at least one battery cell <NUM> of the at least one battery module <NUM> rises over the predetermined temperature, the control unit <NUM> closes a switch of the relay unit <NUM> so that the motor unit <NUM> idles.

If the temperature of the at least one battery cell <NUM> of the at least one battery module <NUM> rises over the predetermined temperature, the control unit <NUM> shifts the gear <NUM> of the vehicle <NUM> to the neutral mode.

If the temperature of the at least one battery cell <NUM> of the at least one battery module <NUM> rises over the predetermined temperature, the control unit <NUM> controls the warning unit <NUM> to send a danger signal to the driver of the vehicle <NUM>.

Specifically, the control unit <NUM> controls the warning unit <NUM> to transmit the danger information of the warning unit <NUM> to the alarm unit <NUM> of the vehicle <NUM>, and control the alarm unit <NUM> to send the danger signal to the driver. Here, the alarm unit <NUM> may transmit the danger signal to the driver by emitting a light through a display or generating a horn through a speaker.

Together with operating the warning unit <NUM>, the control unit <NUM> shifts the gear <NUM> of the vehicle <NUM> to the neutral mode so that the motor unit <NUM> idles. In addition, after a preset predetermined time passes from the operation of the warning unit <NUM>, the control unit <NUM> shifts the gear <NUM> of the vehicle <NUM> to the neutral mode so that the motor unit <NUM> idles.

Hereinafter, the detailed operation of the battery pack <NUM> according to this embodiment when an abnormal situation occurs will be described in more detail.

<FIG> is a diagram for illustrating an operation of the battery pack of <FIG> when an abnormal situation occurs.

Referring to <FIG>, in the battery pack <NUM> of the vehicle <NUM>, an abnormal situation may occur at the battery cell <NUM> of the battery module <NUM>. Specifically, in the battery cell <NUM> of at least one of the battery modules <NUM>, the temperature may rise according to overheating or overcurrent.

If the temperature of the battery cell <NUM> keeps rising over a predetermined temperature, the battery cell <NUM> may explode or ignite, which may lead to a thermal runaway to the battery cells of the surrounding battery modules <NUM>, resulting in an explosion of the entire battery pack or the like. In this case, a great danger is caused to the driver and an occupant of the vehicle <NUM>.

In the battery pack <NUM> of this embodiment, in order to prevent this problem, when the temperature of the at least one battery cell <NUM> rises over the predetermined temperature, the control unit <NUM> controls the battery pack <NUM> and allows the motor unit <NUM> to idle in order to prevent the occurrence of thermal runaway.

Specifically, in the battery pack <NUM> according to this embodiment, when the temperature of the at least one battery cell <NUM> rises over the predetermined temperature, the control unit <NUM> controls the motor unit <NUM> to idle so that the energy level of the battery cells <NUM> of the battery module <NUM> is lowered to prevent thermal runaway. In the case of a state of charge (SOC) of the battery module <NUM> is at a specific SOC or below, thermal runaway does not occur, and even though thermal runaway occurs, only a small amount of heat is released. In this embodiment, the specific SOC or below may be approximately <NUM> percent or below.

Hereinafter, a mechanism for preventing thermal runaway according to this embodiment will be described in more detail.

If the temperature of the at least one battery cell <NUM> of the battery module <NUM> rises above the preset predetermined temperature, the control unit <NUM> may firstly control the warning unit <NUM> to notify this information to the user such as a driver of the vehicle <NUM> such that the user may recognize this danger situation through the alarm unit <NUM> of the vehicle <NUM>.

After that, the control unit <NUM> shifts the state of the gear <NUM> of the vehicle <NUM> to a neutral mode. If the alarm is generated through the warning unit <NUM> and the gear <NUM> is completely shifted to the neutral mode, the control unit <NUM> closes the switch of the relay unit <NUM> to operate the relay unit <NUM> so that the motor unit <NUM> idles.

Accordingly, the energy of the battery module <NUM> is converted into kinetic energy through idling of the motor unit <NUM> and be quickly released. Here, the idling of the motor unit <NUM> may be continued until the SOC is lowered to a predetermined SOC or below.

When an abnormal situation occurs due to overheating of a specific battery cell <NUM>, the battery pack <NUM> according to this embodiment effectively prevents thermal runaway of the battery cell <NUM> through idling of the motor unit <NUM> of the vehicle <NUM> under the control of the control unit <NUM>, thereby significantly reducing the risk of explosion or chain ignition of the battery module <NUM>.

Therefore, the battery pack <NUM> according to this embodiment effectively prevents a large accident of such as explosion of the battery pack <NUM>, even the vehicle <NUM>, when an abnormal situation occurs at the specific battery cell <NUM>.

<FIG> is a flowchart for illustrating a control method when an abnormal situation occurs at the battery pack of <FIG>, while the vehicle of <FIG> is stopped.

Referring to <FIG>, when the vehicle is stopped, the control unit of the battery pack determines whether a temperature of the battery cell of at least one battery module among the battery modules is higher than a preset temperature (S10).

If the temperature of the at least one battery cell is higher than the preset temperature, the control unit operates the warning unit (S12) so that the user such as a driver recognizes the danger situation through the alarm unit.

The control unit determines whether the gear of the vehicle is in a neutral state (S14), and if the gear is not in the neutral state, the control unit shifts the gear to the neutral mode (S15).

After that, the control unit operates the relay unit by closing the switch of the relay unit (S16). Then, the control unit converts the energy of the battery module into kinetic energy through idling of the motor unit and release the energy (S18), in order to lower the SOC of the entire battery module so that thermal runaway does not occur at the battery cell or the battery module.

<FIG> is a flowchart for illustrating a control method when an abnormal situation occurs at the battery pack of <FIG>, while the vehicle of <FIG> is running.

Referring to <FIG>, when the vehicle is running, the control unit of the battery pack determines whether a temperature of the battery cell of at least one of the battery modules is higher than a preset temperature (S20).

If the temperature of the at least one battery cell is higher than the preset temperature, the control unit operates the warning unit (S22) so that the user such as a driver recognizes the danger situation through the alarm unit.

The control unit determines whether the vehicle is stopped (S23). If the vehicle is in a stopped state, the control unit determines whether the gear of the vehicle is in a neutral state (S24), and if the gear is not in the neutral state, the control unit shifts the gear to the neutral mode (S25). Meanwhile, if the vehicle is not in a stopped state but in a running state according to the determination (S23) of whether the vehicle is stopped, the control unit shifts the gear to the neutral mode.

After that, the control unit operates the relay unit by closing the switch of the relay unit (S26). Then, the control unit converts the energy of the battery module into kinetic energy through idling of the motor unit and release the energy (S28), in order to lower the SOC of the entire battery module so that thermal runaway does not occur at the battery cell or the battery module.

<FIG> is a diagram for illustrating a battery pack according to another example of the vehicle of <FIG>, and <FIG> is a diagram for illustrating an operation of the battery pack of <FIG> when an abnormal situation occurs.

Since a battery pack <NUM> of the vehicle <NUM> according to this example is similar to the battery pack <NUM> of the former embodiment, components substantially identical or similar to the former embodiment will not be described in detail, and hereinafter, features different from the former embodiment will be described in detail.

Referring to <FIG> and <FIG>, the battery pack <NUM> includes a battery module <NUM>, a pack case <NUM>, a relay unit <NUM>, a warning unit <NUM>, a control unit <NUM>, and an external resistor unit <NUM>.

The battery module <NUM>, the pack case <NUM>, the relay unit <NUM>, the warning unit <NUM> and the control unit <NUM> are substantially identical or similar to the former embodiment and thus will not be described in detail.

The external resistor unit <NUM> is provided inside the pack case <NUM> or outside the pack case <NUM>, and connects the relay unit <NUM> to the motor unit <NUM> of the vehicle <NUM>.

If the relay unit <NUM> is closed, the external resistor unit <NUM> discharges the energy of the battery module <NUM> as thermal energy. That is, in this embodiment, when the temperature of a specific battery cell <NUM> of at least one of the battery modules <NUM> rises over a predetermined temperature due to overheating or the like, the energy of the battery module <NUM> is also discharged through the external resistor unit <NUM> along with the energy release due to idling of the motor unit <NUM>.

Therefore, when an abnormal situation occurs at a specific battery cell <NUM> of the battery module <NUM> due to abnormal overheating or the like, the battery pack <NUM> according to this embodiment may more effectively prevent the occurrence of a danger situation such as thermal runaway.

According to various embodiments as described above, it is possible to provide the battery packs <NUM>, <NUM> having an improved safety by preventing thermal runaway, the vehicle <NUM> including the battery pack <NUM>, <NUM>, and the control method of the battery pack <NUM>, <NUM>.

Claim 1:
A battery pack (<NUM>) for a vehicle (<NUM>), the vehicle (<NUM>) comprising:
a motor unit (<NUM>) and a gear (<NUM>);
at least one battery module (<NUM>) having at least one battery cell (<NUM>);
a relay unit (<NUM>) configured to connect the at least one battery module (<NUM>) to a motor unit (<NUM>) of the vehicle (<NUM>); and
a control unit (<NUM>) connected to the relay unit (<NUM>) and configured to be connected to the motor unit (<NUM>) and to control the relay unit (<NUM>) and the motor unit (<NUM>),
characterized in that:
when a temperature of the at least one battery cell of the at least one battery module rises over a predetermined temperature, the control unit (<NUM>) being configured to shift the gear of the vehicle to a neutral mode and to close a switch of the relay unit (<NUM>), so that the motor unit (<NUM>) idles.