KR102629554B1 - Safety pad, battery cell and battery module having the same - Google Patents

Abstract

The present invention relates to a safety pad and a battery cell and battery module equipped with the same. The safety pad according to the present invention is a mixture of a base layer, a polymer composition, and a fire extinguishing agent in a roll-to-roll manner. A safety buffer layer is applied to the base layer supplied and formed by curing the applied mixed material while passing through a heating drum and a cooling roll, and the safety buffer layer formed on the base layer is roll-to-roll. It includes a coated layer formed by applying an anti-pollution material while being transported in a method and curing it through a UV lamp and an oven. The polymer composition includes polyol-ether, polyolactone, and lactone), cross-linking agent, catalyst, foaming agent, filler, pigment, foaming agent, and curing agent, and the fire extinguishing agent is sodium hydrogen carbonate, ammonium phosphate, and halogen. ), and is characterized in that it is formed into a high-density sheet including one or more selected from the group consisting of, is wound on a winding roll, and can be cut to the required length after packaging and storage.
According to this, it has the advantage of securing the stability of the battery cell, the battery module containing it, the battery pack constructed therefrom, and the electric vehicle equipped with the battery pack through high buffering function and delay in the spread of fire.

Description

Safety pad and battery cell and battery module having the same {Safety pad, battery cell and battery module having the same}

The present invention relates to a safety pad that can protect battery cells and battery modules from impact and delay the spread of fire by extinguishing substances in the event of a fire, and a battery cell and battery module equipped with the same.

A battery cell is the basic unit of a lithium-ion battery that can be used to charge/discharge electrical energy and is formed by housing an anode material, a cathode material, a separator, and an electrolyte in an aluminum case.

In addition, a battery module is constructed to protect the battery cells configured as above from external shock, heat, vibration, etc., and the battery module is an assembly formed by accommodating a certain number of battery cells in a frame. ) is composed of.

In addition, the battery module configured as above is configured in the form of a battery pack that includes a control system and a cooling system, and is installed and operated as an energy source for power supply to a final system such as an electric vehicle.

Meanwhile, in the case of battery modules applied to electric vehicles, while realizing high energy density, they expand due to heat generated during charging and contract during discharging.

Accordingly, a buffering means is further provided between each battery cell constituting the battery module to cope with such expansion and contraction.

For example, Japanese Patent Publication No. 2020-004556A “Buffering sheet for battery module” discloses a buffering structure for a battery module using a buffering sheet.

Figure 1 shows a diagram for the cushioning structure of a cushioning sheet for a battery module according to the prior art.

Referring to the drawing, a battery module according to the prior art is composed of a plurality of battery cell stacks 12 and restraining members 13a and 13b for restraining the stack, and the target surface 11a of the battery cells 11 A cushioning sheet 14 is interposed between the restraining member or the target surface 11a of an adjacent battery cell to form a buffering structure so that a reaction force can be provided during discharging along with elastic support of the battery cell 11 during charging. .

However, while the cushioning sheet 14 according to the prior art is configured to include a base portion 21 and a trapezoidal protrusion 22 to provide structural cushioning, the battery module There is a problem in that the overall volume increases.

Meanwhile, the battery cells that make up the battery module are frequently overheated due to overcharging or electrical/physical shock, and such overheating can ignite inside the battery module, leading to a fire accident in the electric vehicle.

Therefore, in the case of a battery pack installed in an electric vehicle, it is configured to include a cooling device to cool the battery module and a control device for charge and discharge control to prevent overheating of the battery module, but there is a risk of ignition occurring inside the battery module. In this case, there is a problem in that no action can be taken.

J.P. 2020-004556 A J.P. 6724552 B2 J.P. 6277987 B2 J.P. 5122898 B2

The purpose of the present invention is to provide a safety pad that can delay or extinguish a fire when a battery cell ignites while providing a cushioning function in response to expansion and contraction of the battery cell.

Another object of the present invention is to provide a safety pad that can reduce the increase in volume of the battery module, a battery cell including the safety pad, and a battery module configured to accommodate a plurality of the battery cells.

The safety pad according to the present invention is applied to the base layer, where a base layer and a mixed material containing a polymer composition and a fire extinguishing agent are supplied in a roll-to-roll manner, and the applied mixed material is applied to a heating drum and The safety buffer layer, which is formed by curing through a cooling roll, and the safety buffer layer formed on the base layer are transferred in a roll-to-roll manner, and an anti-pollution material is applied and cured through a UV lamp and oven. It includes a coated layer formed by, and the polymer composition includes polyol-ether, polyol-lactone, crosslinking agent, catalyst, foam stabilizer, filler, pigment, and foaming agent. and a hardener, wherein the fire extinguishing agent includes at least one selected from the group consisting of sodium hydrogen carbonate, ammonium phosphate, and halogen, and is formed into a high-density sheet and wound. It is wound on a roll and can be cut to the required length after packaging and storage.

The anti-pollution material is characterized in that it is formed of one or more types selected from zinc stearate, talc, and magnesium carbonate.

The fire extinguishing agent is characterized in that it is microencapsulated in a core-shell structure with a polymer material and mixed with the polymer composition.

The polyol-ether and polyol-lactone are mixed in the form of a masterbatch (M/B) to form a liquid mixed material, and the polyol-ether is more than three times the amount of polyolactone. It is characterized by being input.

After the mixed material is applied on the base layer, a polyethylene film is additionally supplied to improve smoothness, and the polyethylene film is removed using a peeling roll after passing the cooling roll.

The battery cell according to the present invention is provided on one side with a safety pad having any one of the above features.

The battery module according to the present invention includes a frame that is open at the top and has a predetermined space therein, a cover that shields the upper side of the frame, and a plurality of battery cells accommodated in a predetermined space inside the frame, and the plurality of battery cells are accommodated in a predetermined space inside the frame. A safety pad having any one of the above features is provided between the battery cells and between the other surface of the outermost battery cell and the frame.

The safety buffer layer constituting the safety pad according to the present invention is composed of high-density polyurethane foam with a field density of FD (Field Density) of 200 to 300 and a fire extinguishing agent, so it has not only shock absorption but also high airtightness and prevents fire from spreading in the event of a fire. can be delayed.

Therefore, the electric vehicle battery module to which the safety pad according to the present invention is applied maintains the airtightness of the battery module during operation and performs an excellent buffering function, and in the event of a fire due to battery overheating, it delays the spread of the fire, shortening the evacuation time of the driver and passengers. There are advantages that can be secured.

In addition, the safety pad according to the present invention can be formed in the form of a pad with a thin thickness by including a core-shell structure fire extinguishing agent inside the high-density polyurethane foam to form a safety buffer layer.

Therefore, a more compact structural design is possible when forming a battery module, which has the advantage of reducing the volume of the battery module.

In addition, the safety pad according to the present invention forms a safety buffer layer in multiple layers, so that step-by-step fire delay can be achieved.

That is, in the safety pad according to the present invention, a safety buffer layer containing a mixture of high-density polyurethane and a fire extinguishing agent is formed on the upper side of the base layer to exhibit buffering and fire spread delay functions, and an anti-pollution composition and a fire extinguishing agent are placed on the upper side of the safety pad. Another safety buffer layer mixed with the composition is formed, preventing adhesion of contaminants and performing a function of delaying the spread of fire.

Figure 1 is a diagram showing the cushioning structure of a cushioning sheet for a battery module according to the prior art.
Figure 2 is a diagram showing an embodiment of a safety pad according to the present invention.
FIG. 3 is a view schematically showing the layered structure along the cross-section along section A-A' of FIG. 2.
Figure 4 is a diagram showing an embodiment of the safety pad manufacturing process according to the present invention.
Figure 5 is a diagram showing an example of a safety pad manufacturing facility according to the present invention.
Figure 6 is a diagram showing an embodiment of a battery cell to which a safety pad according to the present invention is applied.
Figure 7 is a diagram schematically showing an example of a battery module to which a safety pad according to the present invention is applied.
Figure 8 is a diagram showing another embodiment of a safety pad according to the present invention.
Figure 9 is a diagram showing the safety pad manufacturing process according to the embodiment of Figure 8.
Figure 10 is a diagram showing another embodiment of a safety pad according to the present invention.
Figure 11 is a diagram showing the safety pad manufacturing process according to the embodiment of Figure 10.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings FIGS. 2 to 11. Meanwhile, in the drawings and detailed descriptions, illustrations and references to structures and operations that can be easily understood by those in the field are simplified or omitted. In particular, in the illustrations and detailed descriptions of the drawings, detailed descriptions and illustrations of specific technical configurations and operations of elements that are not directly related to the technical features of the present invention are omitted, and only the technical configurations related to the present invention are briefly shown or described. did.

FIG. 2 is a drawing showing an embodiment of the safety pad according to the present invention, and FIG. 3 is a drawing schematically showing the layered structure along the cross-section of part A-A' of FIG. 2. Additionally, Figure 4 shows a diagram showing an example of the safety pad manufacturing process according to the present invention, and Figure 5 shows a diagram showing an example of the safety pad manufacturing facility according to the present invention.

Referring to these drawings, first, the safety pad 100 according to the present invention is provided on one side of the battery cell to provide elasticity and airtightness while delaying the spread of fire in the event of a fire.

To this end, the safety pad 100 includes a base layer (120) made of polyethylene film, and a safety buffer layer (Safety buffer) formed on the upper side of the base layer (120) using a polymer composition. layer 140) and a coated layer 160 formed on the upper side of the safety buffer layer 140 to prevent contamination.

The base layer 120 can utilize a ready-made polyethylene film, and is supplied for coating the safety buffer layer 140 using a roll-to-roll method.

The safety buffer layer 140 is formed as a mixture of a high-density polymer composition and a fire extinguishing agent on the upper side of the base layer 120 supplied as described above.

In detail, the polymer composition includes polyol-ether, polyol-lactone, crosslinking agent, catalyst, foam stabilizer, filler, pigment, foaming agent, and curing agent.

The polyol-ether and polyol-lactone are mixed in the form of a masterbatch (M/B) to form a liquid mixed material, and the polyol-ether is added at least three times the amount of polyolactone. .

The filler may be calcium carbonate (CaCO ₃ ), the foaming agent may be nitrous (N2) gas, and the curing agent may be isocyanate.

In addition, the fire extinguishing agent is formed by containing at least one selected from the group consisting of sodium hydrogen carbonate, ammonium phosphate, and halogen.

As an example, the fire extinguishing agent is 1,1,1,2,2-Pentafluoroethane (CF ₃ CF ₂ H, HFC-125), 1,1,1,2,3,3,3-Heptafluoropropane (CF ₃ CHFCF ₃ ), Chlorotetrafluoroethane (CHClFCF ₃ ), fluorochemical ketone compound, dodecafluoro-2-methylpentan-3-one (FK-5-1-12, CF ₃ CF ₂ C(O)CF(CF ₃ ) ₂ )), 1 -chloro-1,2,2,2-tetrafluoroethane(C ₂ HClF ₄ ), 2-chloro-1,1,1,1,2-tetrafluoroethane(CHClFCF ₃ , HCFC-124), decafluorocyclohexanone (perfluoroethane (cyclohexanone), CF ₃ CF ₂ C(O)CF(CF ₃ ) ₂ (-1,1,1,2,4,4,5,5,5-nonafluoro-2-trifluoromethyl -butan-3 one), (CF ₃ ) ₂ CFC(O)CF(CF ₃ ) ₂ (-1,1,1,2,4,5,5,5,6,6,6,-octafluoro -2,4,-bis(trifluoromethyl)pentan-3-one), CF ₃ CF ₂ C(O)CF ₂ CF ₂ CF ₃ , CF ₃ C(O)CF(CF ₃ ) ₂ , 1, 1,1,3,3,4,4,5,5,6,6,7,7,8,8,8,-hexadodecafluorooctane-2-one (CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ C(O)CF ₃ ), 1,1,1,3,4,4,4,-heptafluoro-3-trifluoromethylbutan-2-one (CF ₃ C(O)CF (CF ₃ ) ₂ ), 1,1,1,2,4,4,5,5,-octafluoro-2-trifluoromethylpentan-3-one (HCF ₂ CF ₂ C(O)CF( CF ₃ ) ₂ ), 1,1,1,2,4,4,5,5,6,6,6,-undecafluoro-2-trifluoromethylhexan-3-one (CF ₃ CF ₂ CF ₂ C(O)CF(CF ₃ ) ₂ ), 1-chloro-,1,1,3,4,4,4-hexafluoro-3-trifluoromethyl-butan-2-one ((CF ₃ ) ₂ CFC(O)CF ₂ CL), 1,1,1,2,2,4,4,5,5,6,6,6-dodecafluorohexan-3-one (CF ₃ CF ₂ C(O)CF ₂ CF ₂ CF ₃ ), 1,1,1,5,5,5,-hexafluoropentane-2-4-dione (CF ₃ C(O)CH ₂ C(O)CF ₃ ), 1,1,1,2,5,6,6,6-octafluoro-2,5-bis(trifluoromethyl)hexane-3,4-dione ((CF ₃ ) ₂ CFC(O) C(O)C(O)CF(CF ₃ ) ₂ ), 1,1,1,2,2,3,3,5,5,6,6,7,7,7,-tetradecafluoroheptane -4-one (CF ₃ CF ₂ CF ₂ C(O)CF ₂ CF ₂ CF ₃ ), 1,1,1,3,3,4,4,4-octafluorobutal-2-one (CF ₃ C(O)CF ₂ CF ₃ ), 1,1,2,2,4,5,5,5-octafluoro-1-trifluoromethoxy-4-trifluoromethylpentan-3-one (CF ₃ OCF ₂ CF ₂ C(O)CF(CF ₃ ) ₂ ) and 1,1,1,2,4,4,5,5,6,6,7,7,7,-tridecafluoro-2 -Trifluoromethylheptan-3-one (CF ₃ CF ₂ CF ₂ CF ₂ C(O)CF(CF ₃ ) ₂ ) It may be in the form of a microcapsule filled with one or more selected from the group.

That is, the fire extinguishing agent may be microencapsulated in a core-shell structure together with a polymer material and mixed into the polymer composition.

Meanwhile, the liquid mixed material formed by stirring the polymer composition and the fire extinguishing agent as described above is applied to the base layer 120 supplied in a roll-to-roll method and then formed as the safety buffer layer 140.

In addition, an anti-pollution material is applied to the upper side of the safety buffer layer 140 to prevent adhesion of contaminants to form a coated layer 160, thereby forming a safety pad 100 with a buffer function and a fire spread delay function. do.

Hereinafter, a more detailed manufacturing process will be described along with an example of manufacturing equipment for forming the safety pad 100 as described above.

Referring to Figure 5, the polymer composition and fire extinguishing agent are contained in a mixer 710 and stirred into a liquid mixed material, and the density is adjusted while supplying dinitrogen (N ₂ ) gas.

And, the mixed material contained in the mixer 710 is applied to the base layer 120 supplied in one direction by the first PT roll 730 and the transfer roller 740 using a comma coater 760.

The mixed material applied to the base layer 120 as described above is cured while passing through the oven 810, the heating drum 820, and the cooling roll 830 to form the safety buffer layer 140.

Meanwhile, after the mixed material is applied on the base layer 120, an additional polyethylene film may be supplied to improve smoothness.

For this purpose, a second PT roll 860 is further provided between the comma coater 760 and the oven 810, so that a polyethylene film protective layer can be additionally formed on the upper side of the applied mixed material layer, and a cooling roll 860 After passing through, the polyethylene film protective layer can be removed using the peeling roll 860.

The base layer 120 on which the safety buffer layer 140 is formed is transferred by a transfer roller 840 and applied with an anti-pollution material. The anti-pollution material is zinc stearate, talc, and carbonic acid. It may be formed of one or more types selected from magnesium (magnesium carbonate).

In this embodiment, the anti-pollution material can be applied by gravure coating using a mesh roll 912 and a doctor blade 914, and the base layer 120 onto which the anti-pollution material is applied is applied by a transfer roller 940. The safety pad 100 including the coated layer 160 with an anti-contamination function is manufactured by curing it sequentially through a chamber containing a UV lamp 920 and an oven 930.

In addition, the safety pad 100 can be cut to a certain length by a cutter 950 and then wound on a winding roll 960 to be packaged and stored. When necessary, it can be cut to a required length and used.

Meanwhile, the safety pad 100 manufactured as described above is made of a high-density sheet and has high-density characteristics of FD (Field Density) 200 to 300 based on 3T (3 mm) per 1 m2, which provides high energy buffering as well as It can have airtightness and dimensional stability due to its high recovery rate.

In addition, the safety pad 100 with the above characteristics may be provided on one side of the battery cell 300 to provide a cushioning function when the battery cell 300 expands and contracts.

Figure 6 is a diagram showing an embodiment of a battery cell to which a safety pad according to the present invention is applied. The safety pad 100 can be applied in a form attached to one surface of the case 320 constituting the battery cell 300. there is.

To this end, an adhesive layer may be added to one side of the safety pad 100 or an adhesive may be additionally applied and bonded, and the safety pad 100 may be cut to a size corresponding to one side of the case 320 and attached. You can.

Meanwhile, a plurality of battery cells 300 configured as above may be arranged inside the frame 520 to form a battery module 500 to be protected from external shock, heat, vibration, etc.

Figure 7 shows a diagram showing an example of a battery module to which a safety pad according to the present invention is applied.

Referring to the drawing, the battery cell 300 according to the present invention is arranged in one direction inside the frame 520 with the safety pad 100 attached to one side, so that the battery cell 300 is positioned between the battery cells 300 and the battery cell 300. Safety pad 100 is positioned.

In addition, the safety pad 100 is further provided between the frame 520 and the battery cell 300 on the other side of the outermost battery cell 300, and is provided as a frame ( The upper side of 520 is shielded with a cover 540 to form a battery module 500.

In the battery module 500 configured as above, each battery cell 300 is kept airtight by the safety pad 100 and can be cushioned in the event of external impact or expansion and contraction.

In addition, the safety pad 100 interposed between the battery cell 300 and the frame 520 melts when a fire occurs, and the fire extinguishing agent provided therein acts to delay or extinguish the spread of the fire.

Meanwhile, FIG. 8 shows a drawing showing another embodiment of the safety pad according to the present invention, and FIG. 9 shows a drawing showing the manufacturing process of the safety pad according to the embodiment of FIG. 8.

Referring to these drawings, the safety pad 100 according to this embodiment is separately formed with a first safety buffer layer 142 for delaying the spread of fire and a second safety buffer layer 144 for a buffering function.

In detail, the safety pad 100 according to the present embodiment is supplied with a base layer 120 formed of a polyethylene film in a roll-to-roll manner as in the above-described embodiment, and a fire extinguisher is placed on the upper side of the base layer 120. After the chemical is applied, it hardens to form the first safety buffer layer 142, which is a fire extinguishing agent layer.

Then, the same polymer composition as in the above-described embodiment was applied to the upper side of the first safety buffer layer 142 formed as above using a comma coater (760) and heat-cured to form a second safety buffer layer in the form of a foam sheet. A buffer layer 144 is formed.

In addition, an anti-pollution material is applied to the surface of the second safety buffer layer 144, which is formed in the form of a foam sheet as described above, and is cured through UV and heating to form a coated layer to prevent adhesion of contaminants. (160) is formed.

Meanwhile, FIG. 10 shows a diagram showing another embodiment of the safety pad according to the present invention, and FIG. 11 shows a diagram showing the safety pad manufacturing process according to the embodiment of FIG. 10.

Referring to these drawings, the safety pad 100 according to the present embodiment includes a third safety buffer layer (Third Safety buffer layer 146) for buffering and delaying the spread of the fire so that the delay in the spread of the fire can be sequentially achieved, and a third safety buffer layer (146) for preventing contamination. And a fourth safety buffer layer (148) is separately formed to delay the spread of fire.

In detail, the safety pad 100 according to the present embodiment is supplied with a base layer 120 formed of a polyethylene film in a roll-to-roll manner, as in the above-described embodiment, and a polymer layer is placed on the upper side of the base layer 120. After the composition and fire extinguishing agent are mixed and applied, they are cured to form a third safety buffer layer 146 with a buffering and fire-spreading function.

Then, a mixture of anti-pollution material and fire extinguishing agent is applied to the upper side of the third safety buffer layer 146 formed as described above, and is cured through UV and heating to form a fourth safety buffer that prevents adhesion of contaminants and delays the spread of fire. A layer 148 is formed.

Meanwhile, the fire extinguishing agent injected into the third safety buffer layer 146 and the fourth safety buffer layer 148 may be injected at different proportions, and can primarily delay the spread of fire by forming an outermost layer. A relatively large proportion of fire extinguishing agent is injected into the fourth safety buffer layer 148, and the proportion of fire extinguishing agent is reduced in the third safety buffer layer 146 for secondary delay of fire spread and buffering and airtight functions. You can.

100.........Safety pad 120..........Base layer
140.........Safety buffer layer 160............Coated layer
300.............Battery cell 320............Case
500............Battery module 520...............Frame
540.............Cover

Claims (7)

A base layer,
A mixed material containing a polymer composition and a fire extinguishing agent is applied to the base layer supplied in a roll-to-roll manner, and the applied mixed material is cured while passing through a heating drum and cooling roll to form a safety buffer layer. layer) and
The safety buffer layer formed on the base layer is transferred in a roll-to-roll manner and includes a coated layer formed by applying an anti-pollution material and curing it through a UV lamp and an oven,
The polymer composition includes polyol-ether, polyol-lactone, cross-linking agent, catalyst, foam stabilizer, filler, pigment, foaming agent, and curing agent, and the fire extinguishing agent is hydrogen carbonate. It is formed into a high-density sheet containing at least one selected from the group consisting of sodium hydrogen carbonate, ammonium phosphate, and halogen, wound on a winding roll, packaged, stored, and cut to the required length. A safety pad characterized as being usable.
According to claim 1,
The anti-pollution material is a safety pad characterized in that it is formed of one or more types selected from zinc stearate, talc, and magnesium carbonate.
According to claim 1,
A safety pad, characterized in that the fire extinguishing agent is microencapsulated in a core-shell structure with a polymer material and mixed with the polymer composition.
The method of claim 1, wherein the polyol-ether and polyol-lactone are mixed in a master batch (M/B) form to form a liquid mixed material, and the polyol-ether is A safety pad characterized in that more than three times the amount of polyolactone is added.
According to claim 1,
After the mixed material is applied on the base layer, a polyethylene film is additionally supplied to improve smoothness, and the polyethylene film is removed using a peeling roll after passing the cooling roll.
A battery cell having a safety pad according to any one of claims 1 to 5 on one side.
A frame with an upper side open and a predetermined space formed inside;
A cover that shields the upper side of the frame and
It includes a plurality of battery cells accommodated in a predetermined space inside the frame,
A battery module, characterized in that the safety pad according to any one of claims 1 to 5 is provided between the plurality of battery cells and between the frame and another surface of the outermost battery cell.