Patent Description:
The present invention relates to a battery pack including an energy discharging means and a fire extinguishing means, whereby stability of the battery pack is improved.

With technological development of mobile devices, such as smartphones, laptop computers, and digital cameras, and an increase in demand therefor, research on secondary batteries, which are capable of being charged and discharged, has been actively conducted. In addition, secondary batteries, which are energy sources substituting for fossil fuels causing air pollution, have been applied to an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (P-HEV), and an energy storage system (ESS).

The energy storage system (ESS) is a system that stores a large amount of excess power in a battery in order to use the stored power when needed. The energy storage system serves to uniformly maintain quality of power in connection with new and renewable energy generation and to increase efficiency in use of power by storing power at the time when the amount of use of power is small and using the stored power when the demand for power is high. The ESS may mainly be classified as a grid system ESS, an uninterruptible power supply (UPS), or an ESS for domestic use.

There are a lithium ion battery, a lithium polymer battery, a nickel-cadmium battery, a nickel-hydride battery, and a nickel-zinc battery as secondary batteries that are widely used at present. The operating voltage of a unit secondary battery cell, i.e. a unit battery cell, is about <NUM>. 0V to <NUM>. In the case in which output voltage higher than the above operating voltage is required, therefore, a plurality of battery cells may be connected to each other in series to constitute a cell module assembly. In addition, cell module assemblies may be connected to each other in series or in parallel to constitute a battery module depending on required output voltage or charge and discharge capacities. In general, a battery pack is manufactured using at least one battery module by adding an additional component.

Since a lithium secondary battery has a danger of explosion and fire outbreak due to heat generation, however, one of the important problems is to secure safety thereof. If no appropriate measures are initially taken when an abnormal phenomenon occurs, the temperature of the secondary battery abruptly increases due to heat generation, and thermal runaway occurs due to such an abrupt increase in temperature, whereby the secondary battery may explode, and the heat propagates to another secondary battery adjacent thereto, and therefore a battery pack may greatly damaged. Methods of cooling or thermally insulating the lithium secondary battery in the battery pack may be used to secure safety of the batter pack. However, there is a problem in that it is not possible to dissipate thermal energy generated in the lithium secondary battery, which has high energy density, when an abnormal phenomenon occurs only by using such methods.

Document <CIT> discloses a known method and an arrangement for discharging an energy storage system for electrical energy.

Document <CIT> discloses systems and methods for operating a lithium ion battery high voltage distribution system architecture of known type.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a battery pack having an energy discharging means and a fire extinguishing means provided therein.

A battery pack according to the present invention to accomplish the above object is a battery pack as defined in the appended claims.

In addition, a device according to the present invention includes at least one battery pack according to the present invention.

A battery pack according to the present invention has an advantage in that an energy discharging means and a fire extinguishing means are included such that, when an abnormal phenomenon, such as heat generation or fire outbreak, occurs in a specific battery cell in the battery pack, energy of the battery cell is rapidly discharged and the fire is suppressed, whereby it is possible to inhibit a thermal runaway phenomenon from propagating to a battery cell adjacent thereto.

In addition, the battery pack according to the present invention has an advantage in that the fire extinguishing means is operated using thermal energy generated from the energy discharging means when the abnormal phenomenon occurs, whereby no separate device configured to operate the fire extinguishing means is necessary.

Hereinafter, a battery pack according to the present invention will be described with reference to the accompanying drawings.

<FIG> is a schematic view of a battery pack including an energy discharging means and a fire extinguishing means according to a first preferred embodiment of the present invention.

When describing the battery pack <NUM> with reference to <FIG>, the battery pack <NUM> according to the present invention is configured such that a plurality of battery cells <NUM> is received in a battery pack case <NUM> in a state of being divided into two or more sections. A partition wall <NUM> configured to partition the sections from each other is located between the respective sections. A heat insulation plate configured to perform heat insulation between the sections or a heat dissipation plate or a cooling plate configured to discharge heat generated from the battery cell <NUM> to the outside may be used as the partition wall <NUM>, as needed.

Meanwhile, as shown in <FIG>, the energy discharging means <NUM> and the fire extinguishing means <NUM> are provided in each section, in which a plurality of battery cells <NUM> is received.

Here, the energy discharging means <NUM> serves to, when an abnormal heat generation phenomenon occurs in a specific battery cell <NUM> of the battery pack <NUM>, discharge energy of the battery cell <NUM> as thermal energy, thereby inhibiting a thermal runaway phenomenon due to abnormal heat generation, thus improving safety of the battery pack <NUM>.

In addition, the fire extinguishing means <NUM> is disposed adjacent to the energy discharging means <NUM>, and the temperature of the fire extinguishing means reaches an operating temperature using thermal energy discharged by the energy discharging means <NUM> when an abnormal heat generation phenomenon occurs, whereby it is possible to rapidly extinguish flames in the battery pack <NUM>.

<FIG> is a schematic view of a battery pack including an energy discharging means and a fire extinguishing means according to a second preferred embodiment of the present invention.

The battery pack <NUM> of <FIG> is identical to the battery pack <NUM> of <FIG> except that the energy discharging means <NUM> and the fire extinguishing means <NUM> are only provided in a middle section, among a plurality of divided sections, compared to the battery pack <NUM> of <FIG>.

Meanwhile, when describing the energy discharging means <NUM> in detail with reference to <FIG>, the energy discharging means <NUM> includes a resistor <NUM> having high electrical resistance and an operating switch <NUM> configured to turn on/off electrical connection with battery cells <NUM> in a specific section.

The resistor <NUM> may be selected from well-known resistors, as long as the electrical resistance of the resistor is capable of rapidly discharging energy of the battery cell <NUM> as thermal energy and the thermal energy is capable of providing temperature at which the fire extinguishing means <NUM> located adjacent thereto is operated.

In addition, the operating switch <NUM> may be provided in only one direction of a circuit, as shown in (a) of <FIG>, or may be provided in both directions of a circuit, as shown in (b) of <FIG>.

In the energy discharging means <NUM> described above, when an abnormal heat generation phenomenon occurs, the operating switch <NUM>, which is off while the battery pack <NUM> is normally operated, is turned on, whereby the battery cell <NUM> and the resistor <NUM> are electrically connected to each other. As a result, electrical energy of the battery cell <NUM> is discharged as thermal energy by the resistor <NUM>, which has high electrical resistance, and therefore it is possible to inhibit the abnormal heat generation phenomenon from propagating to battery cells <NUM> adjacent thereto.

In addition, the battery pack <NUM> may further include a controller (not shown) in order to perform overall management of the battery pack <NUM> and to control operation of the energy discharging means <NUM> when an abnormal heat generation phenomenon occurs.

When describing the fire extinguishing means <NUM> with reference to <FIG>, the fire extinguishing means <NUM> may be a solid aerosol fire extinguishing device including a fire extinguishing chemical <NUM>, a cooling portion <NUM>, and a nozzle <NUM>.

Here, the solid aerosol fire extinguishing device is a fire extinguishing system that interrupts chain reaction of combustion through a negative catalyst effect in which radicals of aerosol generated when a solid compound including special ingredients is burned react with active radicals, such as O, H, and OH, around a fire, in order to interrupt chain reaction, thereby suppressing the fire.

Specifically, when the fire extinguishing chemical <NUM> is burned at an operating temperature or higher, aerosol, which is a fire extinguishing material, is generated, the generated aerosol is cooled to an appropriate temperature harmless to human bodies or facilities while passing through the cooling portion <NUM>, the cooled aerosol is sprayed as aerosol particles A through the nozzle <NUM>, and the sprayed aerosol suppresses a fire through the negative catalyst effect described above.

Any of various well-known fire extinguishing chemicals may be used as the fire extinguishing chemical <NUM> of the fire extinguishing means <NUM>. In particular, an aerosol foaming compound (AFC), which is in a solid state at lower than an operating temperature and which is sprayed in the form of aerosol at the operating temperature or higher, is preferably used.

It is preferable for at least one of potassium nitrate, strontium nitrate, and magnesium nitrate to be included as a main ingredient of the AFC. Since decomposition and combustion temperatures vary depending on ingredients of the AFC, it is necessary to set the size and specifications of the resistor to be applied to the energy discharging means <NUM> in consideration of the operating temperature of the AFC.

The operating temperature may have various temperature ranges depending on ingredients included in the AFC. In particular, a temperature range of <NUM> to <NUM> is preferable in consideration of the kind of the AFC and the resistor <NUM> that are generally used.

In addition, the battery pack including the energy discharging means <NUM> and the fire extinguishing means <NUM> according to the present invention may be applied to an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (P-HEV), or an energy storage system (ESS).

Claim 1:
A battery pack (<NUM>) comprising a means configured to, when an abnormal phenomenon, such as fire outbreak or heat generation, occurs in a battery cell (<NUM>), prevent fire or heat from propagating to another battery cell (<NUM>) adjacent thereto, the battery pack (<NUM>) comprising:
a plurality of battery cells (<NUM>);
a case (<NUM>) configured to receive the plurality of battery cells (<NUM>);
an energy discharging means (<NUM>) configured to discharge energy of the battery pack (<NUM>) when the abnormal phenomenon occurs; and
a fire extinguishing means (<NUM>) configured to discharge aerosol at an operating temperature or higher in order to extinguish flames generated in the battery pack (<NUM>),
wherein the energy discharging means (<NUM>) comprises a resistor (<NUM>) having an electrical resistance and an operating switch (<NUM>); and
wherein the fire extinguishing means (<NUM>) is disposed adjacent to the resistor (<NUM>) and a temperature of the fire extinguishing means (<NUM>) reaches the operating temperature using thermal energy generated from the resistor (<NUM>) when the abnormal phenomenon occurs.