KR20220166677A - Battery pack to prevent the spread of fire - Google Patents

Abstract

The present invention relates to a battery pack for easily preventing spread of fire, which can prevent the spread of a fire, has excellent cooling performance, and can achieve weight reduction, in which the battery pack comprises: a housing for accommodating a plurality of battery modules in a lower space; a cooling unit provided inside the housing and configured to cool the battery modules; a fire detection unit provided at a position close to the battery modules to determine whether the fire has occurred; and a fire extinguishing unit provided above the housing and spraying a fire extinguishing agent toward the battery modules when the fire detection unit determines that the fire has occurred.

Description

Battery pack to prevent the spread of fire {Battery pack to prevent the spread of fire}

The present invention relates to a battery pack that can easily prevent the spread of fire, and more specifically, to a battery pack that can prevent the spread of fire, has excellent cooling performance, and can achieve weight reduction.

Recently, as the electric vehicle market gradually expands, interest in lithium-ion batteries, which are the power source of electric vehicles, is also increasing. In particular, electric vehicles are in the limelight as eco-friendly vehicles because they do not use fossil fuels and do not emit smoke, thereby reducing air pollution, and the market share of electric vehicles is gradually increasing.

In this situation, the importance of the battery pack is being further emphasized, and efforts are being made to develop safer and more efficient battery packs.

An electric car requires an enormous amount of power thousands of times that of a smartphone to operate. Therefore, dozens to thousands of battery cells are required. Although the composition may vary slightly depending on the type of electric vehicle, in general, the battery of an electric vehicle is composed of cells < modules < packs, and the upper concept of the constituent units in the order listed above. size will increase. In order to safely and efficiently manage numerous battery cells, they are installed in electric vehicles in the form of modules and packs.

Specifically, a cell, module, or pack is a unit that collects batteries, and a module is made by tying a plurality of battery cells, and a pack is made by tying a plurality of modules. In an electric vehicle, the battery is finally installed in the form of a single pack.

The cell, which is the basis of a battery, must have a high capacity per unit volume to achieve maximum performance in a limited space in a vehicle, and a much longer lifespan than a battery for general mobile devices. In addition, it must have high reliability and stability that can withstand impact transmitted during driving and operate normally even at low or high temperatures.

Several cells are gathered in one frame to be more protected from external shocks such as heat and vibration, and this form is called a module. In addition, a battery pack is a battery management system (BMS) that manages the temperature or voltage of a battery by gathering several modules and adding a cooling device.

In this way, several battery cells are mounted in an electric vehicle in the form of a single pack. In this regard, the battery industry has been focusing on developing high energy density battery cells that can put more energy into the same volume in order to increase the driving distance of electric vehicles, and accordingly, the direction of development is toward securing high energy density and high safety. has been established

On the other hand, there is a growing interest in how to design and configure modules and packs more efficiently. This is because the battery pack specifications are closely related to the overall performance and design of the electric vehicle, since the form that is finally mounted on the electric vehicle is in the form of a pack. In other words, the driving performance and design of an electric vehicle will change depending on how much higher efficiency and slim design the battery pack mounted on the electric vehicle is. Therefore, in recent years, research and development of battery modules and packs have been actively taking place.

However, it is not an easy task to develop a battery pack that is still lightweight, strong against shock, vibration, fire, etc., and that improves battery efficiency by cooling the heat generated from the battery. As a result, lightweight, high safety, and high cooling efficiency are achieved. It is necessary to develop a battery pack that can be used.

Prior Art Republic of Korea Patent Registration No. 10-1364184 relates to a system and method for partial cooling of a mid- or large-sized battery of an electric vehicle, comprising: a plurality of battery modules having a structure in which battery cells are stacked; cooling fans installed in each battery module according to the number of the battery modules; water cooling plates respectively installed in the plurality of battery modules; a manifold connected to the water cooling plate by water channels to distribute fluid to the water cooling plates through respective water channels; a flow control valve for maintaining constant pressure in the water path between the water cooling plate and the manifold; and a controller for receiving cooling system state data transmitted from various sensors for detecting the state of the cooling system and controlling the flow control valve and the cooling fan installed in each battery module according to the driving state of the cooling system.

According to the above conventional technology, energy is consumed until the battery cell temperature does not reach the set temperature value, and cooling is performed only for battery cells and modules that exceed the set temperature value without cooling, thereby reducing incidental energy loss. However, it is difficult to achieve weight reduction of the battery pack due to the cooling method through water cooling, and it is difficult to suppress the spread in case of fire. there is.

Republic of Korea Patent No. 10-1364184

An object of the present invention for solving the problems derived from the foregoing background art is to provide a battery pack that can easily prevent fire spread with high fuel efficiency of an eco-friendly vehicle by reducing the overall weight through lightening of the battery pack.

In addition, an object of the present invention is to provide a battery pack that can easily prevent the spread of fire so that shock resistance and vibration resistance can be secured in the battery pack to improve the safety of the battery module.

In addition, an object of the present invention is a battery pack that can easily prevent the spread of fire, which suppresses the spread of fire as much as possible when signs of fire occur in the battery module due to shock or heat, and can be extinguished inside the battery pack even if a fire occurs. is to provide

The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems to be solved by the present invention that are not mentioned here are those of ordinary skill in the art to which the present invention belongs from the following description. will be clearly understandable.

The above object, according to an embodiment of the present invention, the housing for accommodating a plurality of battery modules in the lower space; a cooling unit provided inside the housing and configured to cool the battery module; a fire detection unit provided at a location close to the battery module to determine whether or not a fire has occurred; and a fire extinguishing unit disposed on an upper portion of the housing and spraying an extinguishing agent toward the battery module when the fire detection unit determines that a fire has occurred. can be achieved

Preferably, the cooling unit divides the inside of the housing so as to separate a Peltier element installed on the top of the housing to cool the internal space, the Peltier element and the battery module into different spaces, and a plurality of fire extinguishing holes. It is characterized in that it includes a cooling cover formed thereon, and a cooling link extending downward from the cooling cover and configured to be in contact with the battery module.

Preferably, a flame retardant urethane foam is filled in the lower space based on the cooling cover to surround the battery module, and an inert gas is filled in the upper space based on the cooling cover.

Preferably, the fire extinguishing unit includes a fire extinguishing agent supply tank for storing and supplying at least one fire extinguishing agent in the form of cooling, suffocation, removal and suppression, and a plurality of fire extinguishing agents disposed to correspond to the fire extinguishing hole of the cooling cover. A driving member that reciprocates in a direction approaching or moving away from the hole, and has a conduit communicating with the fire extinguishing agent supply unit formed therein, and a plurality of extruding and spraying extinguishing agents provided through the conduit formed at the end of the driving member. It is characterized in that it includes a first fire extinguishing nozzle.

Preferably, before the first fire extinguishing nozzle enters the fire extinguishing hole of the cooling cover, a plurality of first fire extinguishing nozzles are kept together in a bundle form, and the first fire extinguishing nozzle passes through a certain point of the fire extinguishing hole When the plurality of first fire extinguishing nozzles are characterized in that the fire extinguishing agent is extruded and sprayed in a radially spread state.

According to the present invention according to the above embodiment, the following effects can be expected.

First, by wrapping the outside of the battery module with urethane, it is possible to improve the stability of the battery module by securing shock and vibration resistance, as well as reducing the overall weight of the battery pack to improve the fuel efficiency of eco-friendly vehicles. there is.

Second, by configuring the outside of the battery module to be wrapped with flame retardant urethane and filling the remaining space with an inert gas, there is an effect of suppressing the spread of an initial fire.

Third, even if a fire occurs in the battery module, the spread can be greatly suppressed through flame retardant urethane and an inert gas, and furthermore, the fire can be extinguished inside the battery pack through a fire extinguishing unit spraying an extinguishing agent.

1 is a perspective view of a battery pack that can easily prevent fire spread according to an embodiment of the present invention;
2 is a conceptual diagram for explaining the internal configuration of a battery pack that can easily prevent the spread of fire according to an embodiment of the present invention;
3 is a conceptual diagram for explaining the operating principle of the present invention,
4 is a conceptual diagram for explaining a specific operating principle and another embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only the present embodiments make the disclosure of the present invention complete, and those skilled in the art in the art to which the present invention belongs It is provided to fully inform the person of the scope of the invention. And terms used in this specification are for describing the embodiments, and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless otherwise specified in the phrase.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. On the other hand, the drawings and detailed descriptions of configurations and their actions and effects, which can be easily known by those skilled in the art, are simplified or omitted, and will be described in detail focusing on parts related to the present invention.

As shown in FIGS. 1 to 3 , a battery pack that can easily prevent fire spread according to an embodiment of the present invention includes a housing 100, a cooling unit 300, a fire detection unit 500, and a fire extinguishing unit 700. ).

First, the housing 100 has a structure for accommodating a plurality of battery modules 10 in a lower space.

Here, the battery module 10 may have a structure in which a plurality of batteries are simply stacked with an insulating film interposed between the batteries.

As another example, the battery module may have a stack folding structure in which the battery is inserted between the folded insulation films by arranging batteries at appropriate intervals above and/or below the insulation film and then folding the insulation film together with the battery in one direction. .

As another example, the battery may be a pouch type battery and the battery module may be a pouch type battery assembly. A pouch-type battery is a battery in which an electrode assembly having a structure of a positive electrode plate, a separator, and a negative electrode plate is sealed inside a battery case together with an electrolyte solution, and may be formed in a plate shape having a substantially rectangular parallelepiped structure having a thin thickness compared to a width as a whole. These pouch-type batteries generally consist of a pouch-type battery case, and the battery case includes an outer coating layer made of a polymer resin with excellent durability, a barrier layer made of a metal material that exhibits barrier properties against moisture, air, etc., and thermal fusion. It is composed of a laminate sheet structure in which internal sealant layers made of polymeric resins are sequentially stacked. In the pouch-type battery, the case may have various structures, and may have a structure in which the outer circumferential surface of the battery case is heat-sealed and sealed in a state in which the electrode assembly is embedded in the battery case of a laminate sheet including a resin layer and a metal layer. At this time, the heat-sealed outer circumferential surface may be fixed between cartridges forming a battery module by fixing the batteries, respectively.

In addition, the battery that can be applied to the present invention includes an electrode assembly composed of a positive electrode plate, a separator, and a negative electrode plate, and a positive electrode lead and a negative lead are electrically connected to a plurality of positive electrode tabs and negative electrode tabs protruding from the positive electrode plate and the negative electrode plate of each battery, respectively. may have been

As the material of the positive electrode plate, aluminum is mainly used. Alternatively, the positive plate may be surface treated with carbon, nickel, titanium, silver, or the like on the surface of stainless steel, nickel, titanium, or aluminum or stainless steel. Furthermore, there is no limit to use as a positive electrode if the material does not cause chemical change of the battery and has high conductivity.

A positive electrode tab is provided in a portion of the positive electrode plate, and the positive electrode tab may be formed in a form in which the positive electrode plate is extended. Alternatively, it is also possible to configure a form in which a member of a conductive material is joined to a predetermined portion of the positive electrode plate through welding or the like. In addition, the positive electrode tab may be formed by coating and drying a positive electrode material on a portion of the outer circumferential surface of the positive electrode plate.

A negative electrode plate corresponding to the positive electrode plate is mainly made of copper. Alternatively, the negative plate may be stainless steel, aluminum, nickel, titanium, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, or the like, and an aluminum-cadmium alloy or the like may be used.

The negative electrode plate is also provided with a negative electrode tab in a partial area, and can be implemented in a form extending from the negative electrode plate like the positive electrode tab described above, and can be joined to a predetermined portion of the negative electrode plate by a method such as welding a member of a conductive material. Alternatively, it is also possible to form the negative electrode material by coating and drying a portion of the outer circumferential surface of the negative electrode plate.

The positive lead is electrically connected to the positive tab provided on the positive electrode plate, and the negative lead is electrically connected to the negative tab provided on the negative electrode plate. Preferably, the positive electrode lead and the negative electrode lead are bonded to a plurality of positive electrode tabs and a plurality of negative electrode tabs, respectively.

The positive electrode plate and the negative electrode plate are coated with a positive active material and a negative active material, respectively. For example, the cathode active material is a lithium-based active material, and representative examples include LiCoO2, LiNiO2, LiMnO2, LiMn2O4, LiFePO4, or Li1+zNi1-xyCoxMyO2 (0≤x≤1, 0≤y≤1, 0≤x+y≤ A metal oxide such as 1, 0≤z≤1, M is a metal such as Al, Sr, Mg, La, Mn) may be used. The anode active material is a carbon-based active material, and as the anode active material, carbon materials such as crystalline carbon, amorphous carbon, carbon composites, and carbon fibers, lithium metal, and lithium alloys may be used. Since the type and chemical composition of the cathode active material and the anode active material may vary depending on the type of battery, it should be understood that the specific examples listed above are only examples.

The separator is not particularly limited as long as it has a porous material. The separator is a porous polymer membrane, such as a porous polyolefin membrane, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trichloroethylene, polymethyl methacrylate, polyacrylonitrile, polyvinyl Pyrrolidone, polyvinyl acetate, ethylene vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butylate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cyanoethyl cellulose Noethyl sucrose, pullulan, carboxyl methyl cellulose, acrylonitrile styrene butadiene copolymer, polyimide, polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polyether ether ketone, polyether sulfone , polyphenylene oxide, polyphenylene sulfide, polyethylene naphthalene, a nonwoven fabric film, a film having a porous web structure, or a mixture thereof. Inorganic particles may be bound to one or both surfaces of the separation membrane.

The inorganic particles are preferably inorganic particles having a high dielectric constant of 5 or more, more preferably inorganic particles having a dielectric constant of 10 or more and a low density. This is because lithium ions moving in the battery can be easily transferred. Non-limiting examples of inorganic particles having a high dielectric constant of 5 or more include Pb(Zr,Ti)O3(PZT), Pb1-xLaxZr1-yTiyO3(PLZT), Pb(Mg3Nb2/3)O3-PbTiO3(PMN-PT), BaTiO3, HfO2, SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO, Y2O3 or mixtures thereof.

Next, the cooling unit 300 is provided inside the housing 100 and configured to cool the battery module 10 .

Specifically, the cooling unit 300 is installed on the upper part of the housing 100 to cool the inner space, the Peltier element 320, the Peltier element 320 and the battery module 10 to different spaces. A cooling cover 340 that divides the inside of the housing 100 so as to be separated and has a plurality of fire extinguishing holes 342 formed therein, and extends downward from the cooling cover 340 to be in contact with the battery module 10 It is characterized in that it comprises a cooling link 360 configured to.

A cooling fin may be formed in the Peltier element 320 to increase a cooling effect by increasing a cooling surface area. These cooling fins are formed extending from the cooling surface among the heating surface and the cooling surface of the Peltier element 320 and are located in the inner space of the housing 100 .

The cooling cover 340 is preferably made of a metal having high thermal conductivity in order to increase cooling efficiency. Considering price and weight, it is preferably made of copper.

Like the cooling cover 340, the cooling link 360 is also preferably made of copper having high thermal conductivity. The cooling link 360 may be configured to surround and cover the battery module 10, and through this, it is possible to prevent the battery module 10 from being separated. In addition, since the battery module 10 can be forcibly cooled by the cooling link 360 , degradation of battery efficiency due to overheating can be prevented.

Meanwhile, a flame retardant urethane foam is filled in the lower space portion based on the cooling cover 340 to surround the battery module 10, and an inert gas is filled in the upper space portion based on the cooling cover 340 characterized by being

The flame retardant urethane foam filled in the lower space based on the cooling cover 340 can protect the battery module 10 from impact and vibration, and can reduce the weight of the battery pack and reduce high-frequency noise generated from the battery. It has a soothing effect.

In addition, the composition can be modified according to the required performance, and it has the advantage of being able to impart functionality by synthesizing polymeric chemicals, and has excellent flame retardancy and self-extinguishing properties, so that fire can be prevented from spreading between battery modules 10.

In the case of existing battery packs, in the form of a box module assembly, there were problems such as heat generation at the upper contact point, vulnerability to corrosion by water cooling devices, vulnerability to heat dissipation when overcharged, and metal weight accounting for 2/3 of the total weight. It has its strengths and has been used continuously. However, using reinforcement materials such as fillers based on urethane materials has the advantage of reducing weight and maintaining high strength.

As such, the present invention can apply flame retardant urethane foam to improve vibration resistance, impact resistance, flame retardancy, and self-extinguishing properties of a battery pack, thereby effectively improving vibration resistance, impact resistance, flame retardancy, and self-extinguishing properties. , The weight of the entire battery pack can be reduced because the weight is less compared to the existing metal holder.

When a fire occurs in the battery pack, the inert gas charged in the upper space portion based on the cooling cover 340 prevents the spread of fire by blocking additional oxygen inflow by the inert gas.

Specifically, nitrogen may be selected as the inert gas. Since nitrogen is an inert gas, it is possible to prevent the spread of fire, and since it is possible to limit the water vapor content in the space, it is possible to prevent condensation during cooling operation.

The nitrogen can directly cool the cooling cover 340 by serving as a refrigerant fluid cooled by the Peltier element 320, and the weight of the battery pack can be reduced by using nitrogen as a refrigerant.

The fire detection unit 500 is provided at a location close to the battery module 10 to determine whether a fire has occurred. The fire detection unit 500 may be a constant temperature type, differential type, compensation type heat sensor or a photoelectric type or ionization type smoke sensor, and may be used alone or in combination in various ways.

The fire extinguishing unit 700 is provided on the upper part of the housing 100, and when the fire detection unit 500 determines that a fire has occurred, it sprays an extinguishing agent toward the battery module 10.

Specifically, as shown in FIGS. 2 and 3, the fire extinguishing unit 700 is a fire extinguishing agent supply tank 720 for storing and supplying at least one fire extinguishing agent among cooling, suffocation, removal and suppression types of fire extinguishing agents. And, a plurality of them are arranged to correspond to the fire extinguishing hole 342 of the cooling cover 340 and reciprocate in a direction closer to or away from the fire extinguishing hole 342, and communicate with the fire extinguishing agent supply tank 720 inside. It is characterized in that it includes a driving member 740 having a conduit, and a plurality of first fire extinguishing nozzles 760 formed at the end of the driving member 740 and extruding and spraying the fire extinguishing agent provided through the conduit. .

Here, referring to FIGS. 3 and 4, before the first fire extinguishing nozzle 760 enters the fire extinguishing hole 342 of the cooling cover 340, a plurality of first fire extinguishing nozzles 760 are arranged side by side in a bundle form. Maintaining a united state, and when the first fire extinguishing nozzle 760 passes through a certain point of the fire extinguishing hole, the plurality of first fire extinguishing nozzles 760 extrude and spray the fire extinguishing agent in a radially spread state to completely extinguish the fire let it be

Meanwhile, as shown in FIGS. 3 and 4, a plurality of second fire extinguishing nozzles 770 communicating with the conduit are formed on the side surface of the drive member 740 to extrude and spray the fire extinguishing agent. The second fire extinguishing nozzle 770 injects the fire extinguishing agent into the upper space with respect to the cooling cover 340 so that the fire can be extinguished.

That is, the first fire extinguishing nozzle 760 extrudes and sprays the fire extinguishing agent to the lower space with respect to the cooling cover 340, and the second fire extinguishing nozzle 770 to the upper space with respect to the cooling cover 340 The fire extinguishing agent is extruded and sprayed. Therefore, by evenly spraying the fire extinguishing agent throughout the inside of the housing 100, the fire can be extinguished regardless of where the fire occurs, and the spread of the fire itself can be blocked in advance.

According to the embodiments of the present invention described so far, the following effects are obtained.

First, by wrapping the outside of the battery module with urethane, it is possible to improve the stability of the battery module by securing shock and vibration resistance, as well as reducing the overall weight of the battery pack to improve the fuel efficiency of eco-friendly vehicles. there is.

Second, by configuring the outside of the battery module to be wrapped with flame retardant urethane and filling the remaining space with an inert gas, there is an effect of suppressing the spread of an initial fire.

Third, even if a fire occurs in the battery module, the spread can be greatly suppressed through flame retardant urethane and an inert gas, and furthermore, the fire can be extinguished inside the battery pack through a fire extinguishing unit spraying an extinguishing agent.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the scope of the invention which follows may be better understood. Those skilled in the art to which the present invention pertains will understand that the present invention can be embodied in other specific forms without changing its technical spirit or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the claims and equivalent concepts should be construed as being included in the scope of the present invention.

10: battery module
100: housing
300: cooling unit
320: Peltier element
340: cooling cover
342: digestive hole
360: cooling link
500: fire detection unit
700: digestion unit
720: fire extinguishing agent supply tank
740: driving member
760: first fire extinguishing nozzle
770: second fire extinguishing nozzle

Claims (5)

A housing accommodating a plurality of battery modules in a lower space;
a cooling unit provided inside the housing and configured to cool the battery module;
a fire detection unit provided at a location close to the battery module to determine whether a fire has occurred; and
a fire extinguishing unit disposed on an upper portion of the housing and injecting an extinguishing agent toward the battery module when the fire detection unit determines that a fire has occurred;
A battery pack that is easy to prevent fire spread, characterized in that it comprises a. According to claim 1,
the cooling unit,
A Peltier element installed on the upper part of the housing to cool the inner space;
A cooling cover partitioning the inside of the housing to separate the Peltier element and the battery module into different spaces and having a plurality of fire extinguishing holes formed therein, and
A battery pack that is easy to prevent the spread of fire, characterized in that it comprises a cooling link configured to extend downward from the cooling cover and connect to the battery module. According to claim 2,
A flame retardant urethane foam is filled in a lower space based on the cooling cover to surround the battery module,
A battery pack that is easy to prevent fire spread, characterized in that an inert gas is charged in the upper space based on the cooling cover. According to claim 3,
The digestion unit,
A fire extinguishing agent supply tank for storing and supplying at least one fire extinguishing agent in the form of cooling, suffocation, removal and suppression;
A driving member arranged in plurality to correspond to the fire extinguishing hole of the cooling cover, reciprocating in a direction approaching or moving away from the fire extinguishing hole, and having a conduit communicating with the fire extinguishing agent supply unit formed therein; and
A battery pack that is easy to prevent fire spread, characterized in that it comprises a plurality of first fire extinguishing nozzles formed at the end of the driving member and extruding and spraying the fire extinguishing agent provided through the pipe. According to claim 4,
Before the first fire extinguishing nozzle enters the fire extinguishing hole of the cooling cover, a plurality of first fire extinguishing nozzles are kept together in a bundle form,
A battery pack that is easy to prevent fire spread, characterized in that when the first fire extinguishing nozzle passes through a certain point of the fire extinguishing hole, the plurality of first fire extinguishing nozzles extrudes and sprays the fire extinguishing agent in a radially spread state.

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