KR20170014309A - Secondary battery, battery module and battery pack with improved safety - Google Patents

Abstract

The present invention relates to a secondary battery capable of securing safety in use of the secondary battery by preventing a fire from spreading when the fire breaks out when the secondary battery is being used, and to a battery module and a battery pack comprising the same. According to the present invention, the secondary battery is in a pouch type in which an electrode assembly is stored in a pouch exterior material, and a flame prevention net is formed in the secondary battery. So, when a fire breaks out as the internal temperature of the secondary battery rapidly increases by penetration of a needle-shaped material through the secondary battery or other abnormal movements, spreading of the fire is prevented, and safety of the secondary battery is improved. Also, a user can rapidly respond to a dangerous situation.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a secondary battery, a battery module, and a battery pack,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary battery, a battery module including the same, and a battery pack. More particularly, the present invention relates to a rechargeable battery for preventing a flame generated in the rechargeable battery from propagating outside the rechargeable battery, And a battery module and a battery pack including the same.

As technology advances, interest in energy storage technology is increasing, and efforts for research and development of electrochemical devices are becoming more concrete as application areas such as mobile phones, camcorders and notebook PCs are expanded. Among the electrochemical devices, development of a rechargeable battery capable of charging and discharging has become a focus of attention. Particularly, the lithium secondary battery has an operating voltage of about 3.6 V and has a larger capacity than a nickel-cadmium battery or a nickel-hydrogen battery, which is widely used as a power source for electronic equipment, and has a high energy density per unit weight. As shown in Fig. 2. Description of the Related Art [0002] Recently, pouch-type secondary batteries which are sealed and used in an electrode assembly and an outer case of a pouch made of a film are widely used because they are easily applicable to various designs of electric products and can reduce their volume.

However, when the secondary battery is overheated, there is a risk of explosion, and securing safety is one of the important problems. Overheating of a secondary battery is caused by various causes, for example, a case where an overcurrent flows beyond a limit through a secondary battery. When the overcurrent flows, the secondary battery generates heat by joule heating, and the internal temperature of the secondary battery rises rapidly. Also, the rapid rise of the temperature causes a decomposition reaction of the electrolyte and causes thermal runaway, which eventually leads to the explosion of the secondary battery. The overcurrent is a phenomenon in which a sharp metallic object passes through a secondary cell or the insulation between an anode and a cathode is destroyed by shrinkage of a separator interposed between an anode and a cathode or a rush current And is applied to a secondary battery or the like.

The rechargeable battery is attracting attention as a power source for electric vehicles (EVs) and hybrid electric vehicles (HEV), which are proposed as solutions for air pollution of existing gasoline vehicles and diesel vehicles using fossil fuels. The middle- or large-sized battery module or the battery pack used for this purpose must be electrically connected to a plurality of lithium secondary batteries in order to provide a required output and capacity in a predetermined device and maintain a stable structure against an external force.

A large number of secondary batteries included in such a middle- or large-sized battery module or a battery pack have advantages of high output as compared with other batteries, but are disadvantageous in that they are vulnerable to safety due to high explosion risk as described above. When the middle or large-sized battery module or the pack includes a plurality of secondary batteries, the problem of stability becomes more serious.

Particularly, when a fire occurs in a conventional pouch-type secondary battery, there is a problem that the flame spreads easily to the outside of the battery module or the battery pack. In this case, the fire spreads to the entire device such as the battery module, There is a serious problem. Accordingly, there is a need to prevent the flame generated in the secondary battery from propagating to the outside of the secondary battery, thereby promptly and promptly responding to the explosion due to the flame or the dangerous condition of the middle or large-sized battery module or the battery pack.

The present invention provides a secondary battery, a battery module including the secondary battery, and a battery pack, which can prevent the flame from spreading further when a fire occurs during use of the lithium secondary battery to secure safety in use of the secondary battery. will be.

The secondary battery according to the present invention is a pouch type secondary battery in which an electrode assembly is housed in a pouch outer casing. By providing a flame prevention net in such a secondary battery, a needle-shaped object penetrates through the secondary battery, When the flame is raised rapidly, it can prevent the flame propagation, thereby improving the safety of the secondary battery from the beginning and responding to the dangerous situation quickly.

The flame-preventing network may be provided inside and / or outside the secondary battery, i.e., at least one of the inside and the outside. The area where the flame prevention network is provided may be part or all of the secondary battery.

For example, the flame-proof network may be provided on a wide surface of an electrode assembly inside the secondary battery, or may be housed in a rear pouch exterior material enclosing the electrode assembly to constitute the secondary battery, . As another example, after forming the pouch exterior material so as to include the flame prevention net in the pouch exterior material, the electrode assembly or the like may be accommodated therein to construct the secondary battery.

 As another example, the flame-proof network may be provided on a large surface of the pouch exterior material or may be provided outside the secondary battery by being provided to surround the pouch exterior material. In this case, the flame-proof network may be integrally formed on the outer surface of the pouch exterior material, or may be a separate member from the pouch exterior material.

The flame-proof network may be one or more layers of metal meshes of two or more meshes, or a plurality of holes formed on a metal plate. The flame-proof network is characterized by being nonflammable. Any of these materials can be used as long as it is difficult to ignite. Preferably, one of copper, aluminum, cast iron, monel (Ni + Cu), stainless steel and steel may be used. The flame-proof network itself may be provided on the inside or outside of the pouch exterior member, or may be laminated with the polymer resin layer. Examples of the polymer resin layer include polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trichlorethylene, polymethyl methacrylate, polyacrylonitrile, polyvinyl pyrrolidone, polyvinyl acetate , Polyethylene-vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinyl alcohol, cyanoethylcellulose, cyanoethyl sucrose, , Carboxymethylcellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, and mixtures thereof, but is not limited thereto.

As described above, the pouch-type secondary battery according to the present invention including the flame-proof network can be extended to a battery module including a plurality of such pouch-type secondary batteries and a battery pack including the same.

That is, the battery module according to the present invention includes a plurality of pouch-type secondary batteries connected in series and / or in parallel, and has a flame-proof network inside and / or outside the battery module.

Also, a battery pack according to the present invention is a battery pack including at least one battery module including a plurality of pouch type secondary batteries connected in series and / or in parallel, wherein at least one of the battery module and / And a flame prevention net is provided outside.

The pouch-type secondary battery, which is a unit constituting the battery module and the battery pack, can use the secondary battery according to the present invention as described above. That is, the secondary battery having the flame-proof network according to the present invention may be connected in series and / or in parallel to form a battery module, and the battery module may include a plurality of battery modules. And the flame prevention net is provided in the frame. In this case, the unit pouch type secondary battery constituting the battery module or the battery pack is provided with the flame prevention net respectively.

Alternatively, a flame-proof network may be provided on the inside and / or outside of the assemblage to form a battery module or a battery pack for assemblies of series and / or parallel connection of general pouch-type secondary batteries having no flame- You may. Also in this case, the area where the flame prevention network is provided may be a part or all of the aggregate.

For example, an example of the battery module according to the present invention may be a structure in which a collection of secondary batteries connected in series and / or in parallel is enclosed in a flame-proof net. The battery pack may include a plurality of such battery modules. Another example of the battery module according to the present invention may be a structure in which an assembly of the secondary cells is enclosed by a flame-proof net, and the structure is housed in a closed box.

As another example, the flame-proof network may be fabricated in the same size as the unit rechargeable battery constituting the assembly and inserted between the two rechargeable batteries, but the position of the flame prevention network is not limited thereto.

Further, another battery module according to the present invention includes: an assembly of secondary batteries connected in series and / or in parallel; An enclosed box capable of accommodating the aggregate; And a flame-protection net disposed on at least one side of the closed box. Here, the flame-proof network may be provided on one surface or the front surface of the closed box, and may be provided on a surface facing the aggregate inside the closed box.

The battery pack according to the present invention can be configured to include at least one battery module as described above. Such a battery pack includes a power tool; An electric vehicle selected from the group consisting of an electric vehicle (EV), a hybrid electric vehicle (HEV), and a plug-in hybrid electric vehicle (PHEV); E-bike; An e-scooter; Electric golf cart; Electric truck; And an electric commercial vehicle. However, the present invention is not limited thereto.

The pouch type secondary battery, the battery module, and the battery pack according to the present invention have a flame prevention net inside and / or outside at least a part of the area, so that when the flame is generated inside the secondary battery due to abnormal behavior, . The flame generated inside the secondary battery not only splits finely while passing through the flame prevention net, but also causes the endothermic reaction in which the flame prevention network absorbs the energy of the flame, , Thereby minimizing additional chain reaction and damage due to flame propagation.

As described above, by providing the flame-proof network according to the present invention, the temperature rise and ignition of the pouch-type secondary battery and the battery module or the battery pack including the pouch type secondary battery can be suppressed, the safety of the secondary battery can be more fundamentally improved, It is possible to respond more quickly and sensitively to dangerous situations of modules or battery packs.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description, serve to further understand the technical idea of the invention, It should not be interpreted.
FIG. 1 shows an example of a secondary battery structure according to the present invention, and FIG. 2 shows another example.
Fig. 3 shows an example of a flame-proof network, and Fig. 4 shows another example.
5 to 7 are schematic cross-sectional views of a pouch type secondary battery according to various embodiments of the present invention.
8 to 10 are schematic cross-sectional views of a battery module according to various embodiments of the present invention.
FIG. 11 is a view showing a method of manufacturing a battery module according to an embodiment of the present invention, and FIG. 12 is a perspective view of the battery module.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It is provided to let you know. The shape of the elements and the like in the drawings are exaggerated in order to emphasize a clearer description, and the same reference numerals denote the same elements.

FIG. 1 shows an example of a secondary battery structure according to the present invention, and FIG. 2 shows another example.

As shown in FIGS. 1 and 2, the present invention relates to a secondary battery structure 20 having a flame arrester 10. Here, the secondary battery structure 20 may be a pouch type secondary battery itself, a battery module including a plurality of such secondary batteries, and a battery pack including at least one such battery module. That is, a cell, a module, or a pack.

In the structure shown in FIG. 1, the flame-proof network 10 is provided in the entirety of the secondary battery structure 20. FIG. In the structure shown in FIG. 2, the flame-proof network 10 is provided in a part of the secondary battery structure 20. FIG. In addition, the flame-preventing network 10 may be provided inside and / or outside the secondary battery structure 20, that is, at least one of the inside and the outside. The flame-proof network 10 may be attached to the secondary battery structure 20 using an adhesive or mechanically.

Meanwhile, in the case where the secondary battery structure 20 shown in FIGS. 1 and 2 is a pouch type secondary battery, a battery module and a battery pack in which such a secondary battery structure 20 includes a repeated structure are also possible. In addition, when the secondary battery structure 20 shown in FIGS. 1 and 2 is a battery module, a battery pack including such a secondary battery structure 20 in a repeated structure is also possible.

The flame-proof network 10 has the purpose and effect of blocking the flame generated in the stability test such as nail penetration, overcharge, inrush current, etc. of the secondary battery and the abnormal operation state. FIGS. 3 and 4 show examples of flame prevention networks.

The flame-proofing network 10 of FIG. 3 is provided with a plurality of holes of a quadrilateral shape on a metal net or a metal plate. The flame-proof network 10 'of FIG. 4 has a plurality of circular holes on the metal plate. The hole can be formed by partially removing the metal plate by punching or etching. The metal net is formed by combining a plurality of metal wires into a so-called wire netting.

As a preferred example, the flame-proof network 10 is formed of one or more layers, preferably a plurality of layers, of metal meshes of two or more meshes. A mesh is a measure of the size of a mesh, expressed as the number of sieves per inch in length. In other words, the mesh is a unit that represents the size of a hole or particle of a sieve, and can be said to be the number of meshes in a 1-inch square. For example, for a 200 mesh, a wire of 2/1000 inches in diameter is flanked by 3/1000 inches, indicating that there is 200 meshes per inch in length. Accordingly, the N mesh is N / 25.4 mm. In the present invention, since a metal mesh of 2 meshes or more is used, the size of one hole is 12.7 x 12.7 mm ² or less.

A general flame prevention net is widely used as a safety device for discharging the vapor from the tank storing the oil which generates the combustible vapor at a relatively low or atmospheric pressure, or installing it in a portion where the outside air is sucked into the tank have. Conventional flame-proof nets are intended to cut off flames with multiple layers of thin wire mesh of 40 mesh or more. The smaller the mesh spacing is, the better, considering only the flaming. However, if the gap is too narrow, it is often clogged by foreign matter such as dust. Therefore, in the present invention, a metal mesh of 2 meshes or more is used as the flame prevention net 10.

This flame-proofing net 10 is characterized by being nonflammable. Any of these materials can be used as long as it is difficult to ignite. Specifically, a material such as copper, aluminum, cast iron, monel (Ni + Cu), stainless steel or steel may be used, but is not limited thereto. In addition, it is preferable that the flame-proof network 10 be made of a material having a mechanical property to withstand an explosion pressure as well as an anti-flammability capable of preventing a flame.

The flame-proof network 10 may be used purely by itself, or may be laminated with a polymer resin layer, but is not limited thereto. Examples of the polymer resin layer include polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trichlorethylene, polymethyl methacrylate, polyacrylonitrile, polyvinyl pyrrolidone, polyvinyl acetate , Polyethylene-vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinyl alcohol, cyanoethylcellulose, cyanoethyl sucrose, , Carboxymethylcellulose, acrylonitrile-styrene-butadiene copolymer, polyimide, and mixtures thereof, but is not limited thereto.

When the flame is generated in the secondary battery included in the secondary battery structure 20, the flame prevention network 10 causes the endothermic reaction to absorb the energy of the flame as well as breaking down the flame while passing through the flame. More specifically, since the flame-proof network 10 has a small hole, a gas such as a gas or a vapor can pass through the flame-preventing network 10, but the flame is hard to pass through. Further, when the mixture of ignitable gas and air in the secondary battery is ignited, the flame prevention net 10 absorbs heat generated from the gas mixture to be burned, thereby lowering the combustion temperature so that the gas on the opposite side does not rise to the autoignition temperature give. This is because the heated high-temperature gas passes through the flame-preventing network 10, and the material constituting the flame-preventing network 10 is heated. The flame-proof network 10 is made of a metal material including a large number of holes, thereby forming a heat absorbing plate having a very wide cross-sectional area.

Therefore, as the flame passes through the flame-proofing net 10, the flame is no longer able to maintain its calories and the explosion is settled.

As described above, according to the present invention, in order to prevent the flame generated inside the pouch-shaped secondary battery from being discharged to the outside, the inside and / or outside of the pouch- And / or the flame prevention network 10 is applied to the outside. The flame-proof network 10 has an effect of suppressing the propagation of the flame to the outside of the secondary battery and minimizing the damage caused by the flame propagation. Accordingly, the stability of the secondary battery structure 20 including the flame-proofing network 10 according to the present invention is improved even under the condition of over-charging, inrush current, and the like even in the case of penetration or penetration by the conductive needle- .

Since the flame-proof net 10 is of a thin plate type, the size of the secondary battery structure 20 can be suppressed from increasing. Further, since the flame-proof network 10 has a plurality of holes, an increase in weight can also be suppressed. As described above, according to the present invention, even when a situation occurs in which the flame is ejected from the secondary battery while suppressing an increase in size and weight of the pouch type secondary battery, the battery module, or the battery pack, .

In general, it is very difficult to control the direction in which the flame is ejected, as compared with a prismatic or cylindrical can-type secondary battery in which the vent or the safety member can be formed on the cap plate side in the pouch type secondary battery. According to the present invention, since the flame in the pouch type secondary battery can be controlled through the flame prevention net, the effect is remarkable, and the improvement of the stability effect in the middle- or large-sized battery module and the battery pack, This is a very necessary technology.

Hereinafter, various embodiments according to the present invention will be described in detail with reference to the drawings.

5 to 7 are schematic cross-sectional views of a pouch-type secondary battery having a flame-proof net according to an embodiment of the present invention.

5, the flame-proof network 10 is placed on a large surface of the electrode assembly 30 inside the pouch-type secondary battery 100, and the flame-proof network 10 includes an electrode assembly 30 In the pouch outer sheath 40. As shown in Fig. The flame prevention network 10 may be provided to surround the electrode assembly 30 by one or several turns instead of being placed on the wide surface of the electrode assembly 30. [

The lithium secondary battery mainly uses a lithium-based oxide and a carbonaceous material as a cathode active material and an anode active material, respectively. The electrode assembly 30 is such that the positive electrode plate and the negative electrode plate coated with the positive electrode active material and the negative electrode active material are disposed with the separator interposed therebetween. At this time, the electrode assembly 30 may be housed in a state where a plurality of positive plates and negative plates are laminated, or one positive plate and a negative plate may be wound. The electrode assembly 30 may be of the stack, folding, stack-folding, jelly-roll type, and the like. The electrode plates of the electrode assembly 30 are formed as a structure in which a current collector is coated with an active material slurry. The slurry may be formed by stirring a granular active material, an auxiliary conductor, a binder, a plasticizer, etc., . Each of the electrode plates may have an uncoated portion to which no slurry is applied. In the uncoated portion, electrode tabs corresponding to the respective electrode plates are formed, and electrode leads are welded to the electrode tabs.

 The pouch case 40 may be a known pouch used as a casing of a secondary battery. Specifically, the pouch case 40 may include a core, a heat-sealable layer formed on the upper surface of the core, and an insulating film layer formed on the lower surface of the core. , And each configuration can use a configuration known in the art. For example, the core portion may be made of aluminum (Al), the heat-sealable layer may be modified polypropylene, and the insulating film layer may be made of any one of nylon and polyethylene terephthalate, but is not limited thereto. At this time, the pouch exterior member 40 may be composed of an upper case and a lower case. The space in which the electrode assembly 30 can be accommodated may be formed in either the upper case or the lower case, or both the upper case and the lower case. On the other hand, when the electrode assembly 30 is housed in the accommodating space of the upper case and the lower case and the electrolyte is injected, the heat-seal layer of the upper case and the heat-seal layer of the lower case are adhered and sealed by heat fusion.

In another embodiment of the present invention, referring to FIG. 6, the flame-proof network 10 is included in the pouch case 40 of the pouch type secondary battery 100. At this time, the flame-proof network 10 may be in the form of being attached to the insulating film layer formed on the bottom surface of the pouch outer casing 40.

In the example shown in FIGS. 5 and 6, the flame-proof network 10 is included in the pouch-type secondary battery 100, and when the secondary battery operates normally, the capacity of the secondary battery is lowered due to side reactions with the electrode active material and the electrolyte , And shorten the life span. When the flame prevention net 10 is included in the pouch-type secondary battery 100, since the high temperature contents including the flame and the heat of the gas are instantaneously absorbed, the influence of the heat or the flame to the outside of the pouch- It can be suppressed more.

7, the flame-proof network 10 may be provided on a wide surface of the pouch case 40 of the pouch type secondary battery 100 or may be provided to surround the pouch case 40 So that it can be provided outside the pouch type secondary battery 100. In this case, the flame-proof network 10 may be integrally provided on the outer surface of the pouch outer casing 40, or may be a member separate from the pouch outer casing 40. With this configuration, even if a situation occurs in which the flame is ejected from the secondary battery 100, since the flame prevention net 10 absorbs the heat such as high temperature contents including the flames instantaneously to lower the temperature, It is possible to discharge the gas or the like to the outside by the hole of the flame prevention net 10 while preventing further diffusion.

5 to 7, the flame-proofing network 10 may be provided inside or outside of the pouch outer casing 40, or may be laminated with the polymer resin layer as mentioned above. This polymer resin layer can prevent the flame prevention network 10 made of a metal material from contacting with an electrode lead or the like in the secondary battery component, and it is possible to prevent the secondary battery from overheating due to a short circuit.

The size of the flame-proof network 10 varies depending on the pouch-type secondary battery 100 having the flame-prevention network 10. More preferably, the size of the flame-proof network 10 is preferably equal to the size of the large surface of the electrode assembly 30 or the wide outer surface of the pouch casing 40, The pouch type secondary battery 100 including the battery 10 has a large effect of suppressing the temperature rise when the temperature rises due to abnormal behavior of the secondary battery and can protect the secondary battery from external impacts .

8 shows a battery module according to another embodiment of the present invention.

The battery module 200 is connected in series and / or in parallel with a plurality of pouch-type secondary batteries 100 including the flame-proof network 10 as shown in FIGS. Accordingly, the battery module 200 is a battery module including a plurality of pouch-type secondary batteries 100 connected in series and / or in parallel, and includes a flame-proof network (not shown) therein. Such a configuration may be a structure in which the unit secondary batteries constituting the battery module 200 are provided with flame prevention networks. A battery pack including at least one of the battery modules 200 may also be constructed according to the present invention.

9 illustrates a battery module according to another embodiment of the present invention. The battery module 300 is provided with a flame prevention network 10 inside and / or outside an assembly 120 in which a plurality of general pouch type secondary batteries 110 that do not include a flame prevention network are connected in series and / or in parallel. The area in which the flame prevention network 10 is provided may be part or all of the aggregate 120. For example, the flame-proof network 10 may be formed to have the same size as that of the unit rechargeable batteries 110 constituting the assembly 120 and inserted between the two rechargeable batteries 110, The position is not limited thereto. A battery pack including at least one of the battery modules 300 may also be constructed according to the present invention.

10 illustrates a battery module according to another embodiment of the present invention. The battery module 400 is a structure in which a plurality of general pouch-type secondary batteries 110, which do not include a flame-proof network, are connected in series and / or in parallel to each other through a flame- The enclosed box 130 for storing this is an optional configuration. A battery pack including at least one of the battery modules 400 may also be configured.

FIG. 11 is a view showing a method of manufacturing a battery module according to an embodiment of the present invention, and FIG. 12 is a perspective view of the battery module.

Referring to FIGS. 11 and 12, the battery module 500 includes an enclosed box 160 in which a plurality of pouch-type secondary batteries 140 are connected in series and / or in parallel to each other. The sealed box 160 is composed of an upper lid 160a and a lower lid 160b.

The assembly 150 is stored in the lower housing box 160b and the upper housing 160a is covered with the upper housing 160a and the lower housing 160b. For example, the upper lid 160a and the lower lid 160b may be sealed by rubber sealing and then bolted together. As another example, the upper cover 160a and the lower housing 160b may be coupled by a sliding coupling means. As another example, ultrasonic welding may be performed between the upper cover 160a and the lower housing 160b. The lower housing 160b may be made of a metal or a carbon material. Another example is high strength steel or high strength composite material.

The assembly 150 may include two or more pouch-type secondary batteries 140 having a series connection or a parallel connection structure. The pouch type secondary battery 140 may be a pouch type secondary battery having a flame prevention net inside and / or outside as proposed in the present invention, or may be a conventional pouch type secondary battery.

The flame prevention network 10 is provided on at least one side of the closed box 160. In this embodiment, the closed box 160 is composed of the upper cover 160a and the lower housing 160b, and the flame-proof network 10 is formed inside the upper cover 160a, so that the flame- 160 are provided on one surface facing the aggregate 150. However, the flame prevention network 10 is not limited to this, and may be provided on one side or on the front surface, either outside or inside of the closed box 160.

On the other hand, the flame prevention net 10 itself can constitute the upper cover 160a. Instead, the laminate of the flame-proof network and the polymer resin layer can be constituted by the upper cover 160a. When the flame is generated, the flame dissolves the polymer resin layer, and the gas or contents serving as a combustion source can be discharged to the outside of the sealed box 160 through the hole of the flame prevention net.

The ordinary battery module is assembled by fixing the pouch type secondary battery to the cartridge and does not have a closed structure. When the sealed box 160 is included as in the battery module 500 according to the embodiment of the present invention, the flame generated in the secondary battery can be confined in the sealed box 160, the direction of the flame can be controlled, Since the flame must pass through the flame prevention net (10), the effect of anti-flame is particularly excellent.

The circular or rectangular can-type secondary battery has a structure that can easily constitute a separate vent portion and can complement safety through it. However, in the case of the pouch type secondary battery, since there is no separate vent portion, it is difficult to control the direction of the flame . In the present embodiment, since the flame is controlled by allowing the generated flame to pass through the flame-proof network by using the sealed box provided with the flame-proof network, stability in the middle- or large-sized battery module including the secondary battery and the battery pack is remarkably increased .

As described above, the battery module provided by the present invention includes: i) a battery module in which the unitary secondary battery included in the battery module includes the flame-proof network (for example, the secondary battery structure 20 of Fig. 1 or 2) And the battery module 200 described with reference to Fig. 8); ii) The unitary rechargeable battery included in the battery module does not have a flame-proof network, but a battery module having a flame-proof network unit (for example, the battery modules 300, 400, 500)); Or iii) a battery module (a battery module 500 described with reference to FIGS. 11 and 12 or a combination of the embodiments described above) having a flame-proof network in units of battery modules as well as a secondary battery included in the battery module It is possible.

Meanwhile, since the pressure or propulsion force of the flame is different depending on the type of the secondary battery, the condition of the flame prevention network is taken into account when constructing each pouch type secondary battery, the battery module or the battery pack. It is needless to say that the position, area, and quantity of the flame-proof network can be adjusted according to the desired volume, weight and the like in consideration of the usage and capacity of the secondary battery, the battery module, or the battery pack. By selecting the flame prevention net through all these considerations, it is possible to prevent the secondary battery, the battery module or the battery pack from ejecting the flame to the outside even when a situation occurs in which the flame is ejected from the secondary battery while suppressing increase in size and weight of the secondary battery, And to improve safety.

The battery pack according to the present invention includes the battery module as described above. Such a battery pack includes a power tool; An electric vehicle selected from the group consisting of an electric vehicle (EV), a hybrid electric vehicle (HEV), and a plug-in hybrid electric vehicle (PHEV); E-bike; An e-scooter; Electric golf cart; Electric truck; And an electric commercial vehicle.

As described above, according to the present invention, by applying a flame-proof network that absorbs and disperses a flame generated by explosion of a lithium secondary battery having a high risk of explosion in the discharge process, it is possible to perform a stability test such as nail penetration, Since the flame is controlled in a pouch-type secondary battery in which the direction of the flame is difficult to control, the stability in the middle- or large-sized battery module and the battery pack including such a secondary battery is remarkably increased do.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but many variations and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the appended claims.

10, 10 ': Flame-proof network
20: Secondary battery structure
30: Electrode assembly
40: Pouch Exterior Material
100, 110, 140: Pouch type secondary battery
120, 150: aggregate
130, 160: sealed box
200, 300, 400, 500: Battery module

Claims (24)

A pouch type secondary battery in which an electrode assembly is accommodated in a pouch outer casing,
And a flame-proof net inside and / or outside the secondary battery. The pouch-type secondary battery according to claim 1, wherein the flame-proof network is provided on a wide surface of the electrode assembly or encloses the electrode assembly. The pouch type secondary battery according to claim 1, wherein the flame prevention net is contained in the pouch exterior material. 2. The pouch type secondary battery according to claim 1, wherein the flame-proof network is provided on a large outer surface of the pouch exterior material or encloses the pouch exterior material. [6] The pouch type secondary battery according to claim 4, wherein the flame prevention net is integrally provided on an outer surface of the pouch exterior member, or is a separate member from the pouch exterior member. The pouch-type secondary battery according to claim 1, wherein the flame-proof network comprises one or more metal nets of 2 meshes or more. The pouch type secondary battery according to claim 1, wherein the flame-proof network is made of copper, aluminum, cast iron, monel (Ni + Cu), stainless steel or steel. The pouch type secondary battery according to claim 1, wherein the flame-proof network is provided on the inside or outside of the pouch exterior member, or is laminated with the polymer resin layer. The method according to claim 8, wherein the polymer resin layer is at least one of polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trichlorethylene, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrole Polyvinyl acetate, polyethylene-vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinyl alcohol, cyanoethylcellulose, cyano Wherein the polymer is any one selected from the group consisting of methyl cellulose, ethyl cellulose, ethyl cellulose, ethyl cellulose, ethyl cellulose, ethyl cellulose, ethyl cellulose, ethyl cellulose, ethyl cellulose, methyl cellulose, ethyl cellulose, ethyl cellulose, carboxymethyl cellulose, acrylonitrile-styrene-butadiene copolymer, polyimide and mixtures thereof. A battery module comprising the pouch type secondary battery according to any one of claims 1 to 9. A battery pack comprising the battery module according to claim 10. 1. A battery module comprising an assembly in which a plurality of pouch type secondary batteries are connected in series and / or in parallel,
And a flame-proof net inside and / or outside the battery module. 13. The battery module according to claim 12, wherein the flame-proof network comprises one or more layers of metal meshes of two or more meshes. 13. The battery module according to claim 12, wherein the flame-proof network is made of copper, aluminum, cast iron, mono (Ni + Cu), stainless steel or steel. 13. The battery module according to claim 12, wherein the flame-retardant network itself is provided purely inside or outside the aggregate, or is laminated with a polymer resin layer. 13. The battery module of claim 12, wherein the flame-proof network is provided to surround the assembly. 17. The battery module of claim 16, further comprising a sealed box for containing the assembly. A battery pack comprising the battery module according to any one of claims 12 to 16. An assembly of pouch-type secondary batteries connected in series and / or in parallel;
An enclosed box capable of accommodating the aggregate; And
And a flame-proof net disposed on at least one side of the sealed box. The battery module according to claim 19, wherein the flame-proof network is provided on one or both sides of the closed box. 21. The battery module according to claim 20, wherein the flame-proof network is provided on a surface of the closed box facing the aggregate. 20. The battery module according to claim 19, wherein the flame-proof network comprises one or more metal nets of two or more meshes. The battery module according to claim 19, wherein the flame-proof network is made of copper, aluminum, cast iron, mono-nickel (Ni + Cu), stainless steel or steel. The battery module according to claim 19, wherein the flame-proof network is provided inside the sealed box purely by itself, or laminated with a polymer resin layer.

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