Fire suppressant for secondary battery, fire-suppressing member for secondary battery, and secondary battery

Abstract

An embodiment of the present invention provides a fire suppressant, a fire-suppressing member, and a secondary battery comprising same, the fire suppressant comprising: at least one first material having decomposition onset temperatures; and a second material mixed with the first material to bind the first material, wherein the first material can be decomposed, when reaching the decomposition onset temperatures, thereby rendering combustible organic compounds non-combustible.

Description

Secondary battery fire suppression agent, secondary battery fire suppression member, and secondary battery

[0001] The present invention relates to a secondary battery fire suppressant, a secondary battery fire suppression member, and a secondary battery, and more particularly, to a secondary battery fire suppressant, a secondary battery fire suppression member, and a secondary battery capable of effectively suppressing a fire in a secondary battery.

[0002] Secondary batteries with high electrical energy density can be vulnerable to shock.

[0003] Secondary batteries can cause a thermal runaway in a short period of time by instantly releasing high energy accumulated due to internal defects or external impacts, which can lead to fire, making it very difficult to respond to accidents.

[0004] If a fire breaks out in a secondary battery, the normal response is to try to extinguish it.

[0005] Lithium present in secondary batteries has a melting point of 108.5 o Liquefy at C, 500 o It vaporizes rapidly above C. When a secondary battery experiences thermal runaway, a white gas is generated, and the main component of this white gas is vaporized lithium. As lithium vaporizes, the pressure inside the battery cell increases, and 1337 o C is completely vaporized. If the battery cell cannot withstand this increase in pressure and bursts, the lithium gas reacts rapidly with oxygen, generating flames and heat, and a thermal runaway occurs.

[0006] Therefore, relying on post-fire extinguishment, as has been the case in the past, is not an appropriate way to deal with secondary battery fires. Therefore, new technologies are needed to prevent thermal runaway in secondary batteries in advance, or to quickly suppress fires if thermal runaway occurs.

[0007] [Prior Art Literature]

[0008] [Patent Document]

[0009] (Patent Document 0001) Republic of Korea Patent Publication No. 10-2022-0125085

[0010] In order to solve the technical problem to be achieved by the present invention, the purpose is to provide a fire suppressant capable of effectively suppressing a fire in a secondary battery and a fire suppression member including the same.

[0011] The technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0012] A fire suppressant according to one embodiment of the present invention comprises: one or more first materials having a decomposition initiation temperature; and a second material mixed with the first material to bind the first material; wherein the first material can decompose when the decomposition initiation temperature is reached to render a combustible organic compound non-combustible.

[0013] The first material may be a digestible material, and the second material may be an organic binder.

[0014] The above-mentioned extinguishing agent comprises two or more extinguishing agents, wherein the two or more extinguishing agents have two or more decomposition initiation temperatures and can be decomposed in stages to render the flammable organic compound non-combustible.

[0015] The first material may include one or more of carbonate, chloride, hydroxide, and phosphate.

[0016] The above carbonate may include one or more of sodium carbonate (Na2CO3), sodium bicarbonate (NaHCO3), potassium carbonate (K2CO3), potassium bicarbonate (KHCO3), ammonium carbonate ((NH4)2CO3), and ammonium bicarbonate (NH4HCO3).

[0017] The above chloride may include one or more of ammonium chloride (NH4Cl), potassium chloride (KCl), aluminum chloride (AlCl3), and sodium chloride (NaCl).

[0018] The above hydroxide salt may include one or more of sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca(OH)2), and magnesium hydroxide (Mg(OH)2).

[0019] The above phosphate may include one or more of ammonium phosphate ((NH4)3PO4), sodium phosphate (Na3PO4), and potassium phosphate (K3PO4).

[0020] The above fire suppressant may be provided in one or more of a paste, liquid, or gaseous form.

[0021] The second material may include one or more of an organic adhesive and an elastomer.

[0022] A fire suppression member according to another embodiment of the present invention comprises: a pair of fiber members; and

[0023] A fire retardant comprising at least one extinguishing agent that is provided between a pair of the above fiber members and has a decomposition initiation temperature and can decompose to render a combustible organic compound non-combustible when the decomposition initiation temperature is reached; and an organic binder mixed with the extinguishing agent, thereby rendering a combustible organic compound non-combustible.

[0024] According to another embodiment of the present invention, a secondary battery comprises at least one extinguishing agent having a decomposition initiation temperature; and an organic binder mixed with the extinguishing agent; wherein the extinguishing agent may include a fire retardant capable of decomposing and rendering a combustible organic compound non-combustible when the decomposition initiation temperature is reached.

[0025] According to one embodiment of the present invention, a fire suppressant, a fire suppression member, and a secondary battery including the same can be provided that can effectively suppress a fire in a secondary battery.

[0026] Figure 1 is a conceptual diagram of a secondary battery fire suppressant according to one embodiment of the present invention.

[0027] FIG. 2 is a Fourier transform infrared analysis (FRIT) experimental graph of carbon monoxide and acetylene gases generated during thermal runaway of a secondary battery cell according to one embodiment of the present invention.

[0028] Figure 3 is a photograph showing a paste form of a secondary battery fire suppressant according to one embodiment of the present invention.

[0029] FIG. 4 is a photograph showing a secondary battery fire suppression member according to one embodiment of the present invention.

[0030] FIG. 5 is an exemplary diagram illustrating an example of use of a secondary battery fire suppression member according to one embodiment of the present invention.

[0031] Hereinafter, the present invention will be described with reference to the attached drawings.

[0032] However, the present invention may be implemented in various different forms and is therefore not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description have been omitted, and similar parts have been designated with similar reference numerals throughout the specification.

[0033] In describing the present invention, detailed descriptions of known technologies related to the present invention will be omitted if they are deemed to unnecessarily obscure the gist of the invention. Furthermore, the terms described below are defined based on their functions within the present invention and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0034] The technical idea of ​​the present invention is determined by the claims, and the following examples are merely a means of efficiently explaining the technical idea of ​​the present invention to a person having ordinary skill in the technical field to which the present invention belongs.

[0035] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the present invention. The singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprise" or "have" specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0037] FIG. 1 is a schematic illustration of a secondary battery fire suppressant according to one embodiment of the present invention.

[0038] As shown in Fig. 1, the secondary battery fire suppressant (100) is intended to suppress a fire in a secondary battery and may include a first material and a second material. The first material is a material having a decomposition initiation temperature and extinguishing properties, and may be referred to as one of a fire extinguishing agent, a fire extinguishing material, and a fire extinguishing powder when describing embodiments of the present invention hereinafter. In addition, the second material is a material that is mixed with the first material and binds the first material, and may be referred to as an organic binder (120) when describing embodiments of the present invention hereinafter.

[0039] A secondary battery fire suppressant (100) according to one embodiment of the present invention may include a fire extinguishing material (110) and an organic binder (120). The fire extinguishing material (100) refers to a composition having fire extinguishing properties that can function in a liquid, gaseous, solid, powdery, etc. state, and is hereinafter sometimes described as a fire extinguishing material (100) or a fire extinguishing powder (100), but this is for the purpose of describing a representative example and is not to be interpreted as being limited to a specific state or form.

[0040] The extinguishing agent (110) may be a carbonate ion that has reactivity with lithium and may be combined with a monovalent or divalent cation, which may cause asphyxiation in the fire by blocking contact with oxygen.

[0041] The digestible substance (110) may be an inorganic salt, for example, an inorganic salt powder. In addition, the inorganic salt preparation may include alkali metals, alkaline earth metals, and ammonium-based substances on the periodic table that have strong oxygen radical absorption capabilities.

[0042] The alkali metal series may include one or more of sodium carbonate (Na2C03), sodium bicarbonate (NaHCO3), potassium carbonate (K2CO3), and potassium bicarbonate (KHC03).

[0043] And, as alkaline earth metals, one or more of magnesium hydrogen carbonate (Mg(HC03)2), magnesium carbonate (MgC03), calcium carbonate (CaC03), and calcium bicarbonate (Ca(HC03)2) may be included.

[0044] Additionally, the ammonium-based substance may include at least one of ammonium carbonate ((NH4)2C03) and ammonium bicarbonate (NH4HC03).

[0045] The digestible substance (110) may specifically be an inorganic carbonate.

[0046] When carbonates are decomposed by heat, reactive decomposition gases and cationic metal ions can be automatically emitted.

[0047] When secondary batteries are damaged by internal or external factors, such as separator damage or external pressure, the resulting short circuit between the anode and cathode increases resistance. This, in addition to the resulting resistive heat, triggers a rapid exothermic reaction that causes thermal decomposition of the electrolyte and the release of flammable and toxic gases. This, in turn, causes a rapid increase in the temperature and internal pressure of the secondary battery, as shown in Table 1 below.

[0048] Pressure (atmospheric pressure)0.000010.00010.0010.010.11Temperature ( o C)52461272287110641337

[0049] Here, when a carbonate included in a secondary battery fire suppressant according to an embodiment of the present invention, for example, a carbonate included in a lithium battery, is exposed to such heat, it may react and decompose as shown in the reaction formula below.

[0050] This phenomenon is influenced by organic substances inside the battery cell, but the biggest factor is that lithium ions gain electrons to become lithium metal and vaporize themselves, or combine with nitrogen in the air to form lithium nitride, as shown in [Chemical Formula 1] and [Chemical Formula 2] below.

[0051]

[0052] [Chemical Formula 1]

[0053] Li + + e - → Li

[0054] [Chemical Formula 2]

[0055] 6Li + N2→ 2Li3N

[0056]

[0057] And, as seen in [Chemical Formula 3] to [Chemical Formula 5] below, lithium or lithium nitride reacts rapidly with water vapor or oxygen, generating strong heat and burning into lithium peroxide or lithium oxide.

[0058] [Chemical Formula 3]

[0059] 4Li + O2→ 2Li2O

[0060] [Chemical Formula 4]

[0061] 4Li + 2H2O + O2→ 4LiOH

[0062] [Chemical Formula 5]

[0063] 2Li + H2O → Li2O + H2

[0064]

[0065] Meanwhile, in such a high-temperature environment, the carbonate according to the embodiment of the present invention may decompose to generate reactive decomposition gas and cationic metal ions.

[0066] The reactive decomposition gas generated can decompose the flammable gas (lithium gas) emitted from the secondary battery. The reactive decomposition gas emitted when carbonate is decomposed by heat may be carbon dioxide (C02).

[0067] Additionally, cationic metal ions can absorb radicals generated from electrical sparks or flames, thereby preventing chain reactions of combustion.

[0068] As shown in Chemical Formulas 6 and 7 below, if a fire occurs in a secondary battery, the generated heat can decompose the carbonate, releasing carbon dioxide. The vaporized lithium then reacts with carbon dioxide and oxygen to convert into carbonate, rendering it non-flammable.

[0069] In this way, as the carbonate decomposes, it releases carbon dioxide, and when the carbon dioxide blocks oxygen access due to the suffocating effect, combustion resulting from a secondary battery fire can be effectively contained or effectively extinguished.

[0070]

[0071] [Chemical Formula 6]

[0072] 4Li + 2CO2+ O2→ 2Li2CO3

[0073] [Chemical Formula 7]

[0074] 2Li + 2CO2+ H2O + 1 / 2O2→ 2LiHCO3

[0075]

[0076] Meanwhile, in situations where the temperature and internal pressure of a secondary battery rapidly increase due to various causes, sparks generated inside the secondary battery may cause ignition of the secondary battery by generating radical ions.

[0077] When the carbonate included in the digestible material (110) according to an embodiment of the present invention is decomposed by heat, cationic metal ions (e.g., alkali metals or alkaline earth metals) may be generated.

[0078] Here, radical ions can be absorbed by cationic metal ions. This suppresses spark generation in the secondary battery and prevents ignition of the secondary battery. In other words, this anti-catalytic effect suppresses the chain reaction of combustion in the secondary battery. Therefore, fires in secondary batteries containing the secondary battery fire suppressant according to an embodiment of the present invention can be prevented, and the spread of any fires that occur can be suppressed.

[0079]

[0080] Here, the carbonate that may be included in the extinguishing material (110) according to the embodiment of the present invention may be one or more of sodium carbonate (Na2CO3), sodium bicarbonate (NaHCO3), potassium carbonate (K2CO3), potassium bicarbonate (KHCO3), magnesium hydrogen carbonate (Mg(HCO3)2), magnesium carbonate (MgCO3), calcium carbonate (CaCO3), calcium bicarbonate (Ca(HCO3)2), ammonium carbonate ((NH4)2CO3), and ammonium bicarbonate (NH4HCO3). Here, depending on the decomposition initiation temperature of each carbonate as shown in Table 2 below, one carbonate may be included, or two or more of these may be combined and included.

[0081] Classification Chemical formula Molecular weight Decomposition onset temperature ( oC) Ammonium bicarbonate NH4HCO3 79.0641-45 Ammonium carbonate (NH4)2CO3 96.0960 Sodium bicarbonate NaHCO3 84.80 Sodium carbonate Na2CO3 105.99100 Potassium bicarbonate KHCO3 100.1100-200 Potassium carbonate K2CO3 138.2850 Magnesium carbonate MgCO3 84.3350 (anhydrous bone) 165 (trihydrate)

[0082] Here, the decomposition initiation temperature may be the temperature at which the carbonate begins to decompose. As described in Table 2, each carbonate may have a unique decomposition initiation temperature. Depending on the user's needs, such as the temperature at which the desired carbonate must decompose to exhibit its fire suppression function, reactivity with organic substances that may be included in the secondary battery, weight adjustments based on differences in molecular weight, etc., the carbonate may be selected and included in the secondary battery fire suppressant.

[0083]

[0084] In addition, as shown in Table 3 below, two or more carbonates may be combined and included in the secondary battery fire suppressant. This combination is intended to achieve stepwise fire suppression, and has the effect of further ensuring the effect of fire suppression. Here, since the carbonate begins to decompose at the decomposition initiation temperature at which the carbonate decomposes as described in Table 2, thereby achieving the fire suppression function, the secondary battery fire suppressant according to an embodiment of the present invention may include 50% or more of a carbonate having a decomposition initiation temperature closest to the dangerous temperature of fire occurrence. In addition, the carbonate having a decomposition initiation temperature closest to the dangerous temperature of fire occurrence while being equal to or lower than the dangerous temperature may be included 50% or more.

[0085] Decomposition onset temperature 60 o C100 o C150 o C Ammonium carbonate 55 wt% 10 wt% Potassium bicarbonate 20 wt% 60 wt% 10 wt% Magnesium carbonate 5 wt% 10 wt% 70 wt%

[0086] Here, the decomposition initiation temperature at which the decomposition of the carbonate begins to suppress the fire can be selected. This selection can be based on the settings of the manufacturer of the lithium-ion secondary battery or the manufacturer of the product in which the lithium-ion secondary battery is mounted. The temperature determined as a dangerous temperature may vary depending on the production and usage environments of the secondary battery user. For example, a lithium-ion secondary battery may be determined to have a fire risk or a fire may have occurred at temperatures above 60°C. This is because, depending on the situation, a lithium-ion secondary battery may be determined to have a fire risk or a fire may have occurred at temperatures above 100°C. Therefore, a specific temperature range considering the usage temperature range of the secondary battery is determined to be a dangerous temperature range, and a carbonate may be included so as to have a decomposition initiation temperature that falls within the dangerous temperature range, or a carbonate that does not fall within the dangerous temperature range but has a decomposition initiation temperature lower or higher than the dangerous temperature may be additionally selected and mixed.

[0087] For example, as shown in Table 3, if the user determines that the hazardous temperature range is 60°C or higher, the carbonate may include 55 wt% ammonium carbonate, 20 wt% potassium bicarbonate, and 5 wt% magnesium carbonate. The carbonate may be formed by mixing these. In this case, ammonium carbonate, which accounts for the largest wt%, may be decomposed first at the hazardous temperature of 60°C, and the primary digestion process may proceed. However, if the primary digestion process does not proceed and the temperature further increases to 100-120°C, potassium bicarbonate, which accounts for the next largest wt%, may be decomposed, and the secondary digestion process may proceed. Nevertheless, if the temperature further increases to the decomposition initiation temperature of magnesium carbonate, a tertiary digestion process by magnesium carbonate may proceed. That is, as the temperature increases, the digestion process may proceed in stages.

[0088] If the carbonate is composed solely of substances with a decomposition onset temperature within the hazardous temperature range, decomposition of all substances will occur at that temperature, and the extinguishing process will begin. However, if complete extinguishment is not achieved despite this extinguishing process, the rapid increase in the fire temperature will not be prevented, preventing the onset of thermal runaway. This will not provide the driver with time to evacuate the vehicle.

[0089] However, as in the embodiment of the present invention, when two or more carbonates are combined and the carbonates have a decomposition initiation temperature equal to or lower than the lower limit of the dangerous temperature range while not falling within the dangerous temperature range, and the extinguishing process is carried out in stages, a rapid increase in the fire temperature can be prevented and the occurrence of thermal runaway can be delayed. This has the effect of providing time for the driver of the vehicle to evacuate.

[0090]

[0091] Secondary batteries contain a variety of organic compounds as anodes, cathodes, and electrolytes. A characteristic phenomenon of secondary battery fires is thermal runaway, which occurs when high-temperature flammable gases are emitted from the cells within the battery, combining with oxygen inside and outside the pack, resulting in an electrical short or high-temperature ignition. This can lead to thermal runaway and flame generation. Toxic substances can be generated during this process.

[0092] Table 4 below shows the main gases generated during thermal runaway of an exemplary secondary battery.

[0093] Combustible Gas Volume Content (%) Hydrogen 30.6% Carbon Dioxide 29.9% Carbon Monoxide 21.3% Methane 7.2% Ethylene 5.6% Propane or Propylene 2.0% Ethane 1.8% Other 1.6%

[0094]

[0095] FIG. 2 is a graph for examining gases generated during thermal runaway and fire in a secondary battery including a secondary battery fire suppressant according to one embodiment of the present invention.

[0096] Fire suppressants can be included in secondary batteries in various forms. FIG. 2 is a Fourier transform infrared analysis (FRIT) experimental graph of hydrogen chloride and hydrogen fluoride gases generated during thermal runaway and fire of a secondary battery in the case where a member impregnated with a secondary battery fire suppressant according to an embodiment of the present invention is attached ('CO ppm absent' and 'C2H6ppm absent') and not attached ('CO ppm' and 'C2H6ppm').

[0097] As illustrated in FIG. 2, it can be confirmed that a secondary battery including a secondary battery fire suppressant (100) effectively suppresses carbon monoxide (CO) and acetylene (C2H6), which are combustible gases generated in the event of a secondary battery fire, compared to a case where the secondary battery is not attached. In this way, the secondary battery fire suppressant (100) according to one embodiment of the present invention can effectively suppress or neutralize fire generated in the event of secondary battery thermal runaway and fire.

[0098] This neutralization can be explained by adsorption and conversion reactions. That is, the secondary battery fire suppressant may be a combination of one (1) or two (2) or more of carbonate ions, chloride ions, hydroxide ions, and phosphate ions that cause adsorption and conversion reactions in response to fires that occur during thermal runaway of secondary batteries, and one (1) or two (2) or more of monovalent, divalent, and trivalent cations.

[0099] A secondary battery fire suppressant according to one embodiment of the present invention may be provided in one (1) or two (2) or more of a paste, a liquid, and a gaseous state. The secondary battery fire suppressant provided in this manner may be positioned in a separately partitioned area inside the secondary battery. In addition, the secondary battery fire suppressant may not be positioned in a separately partitioned area but may be positioned inside the secondary battery in a state of being impregnated in a sheet or the like. In this case, the sheet impregnated with the secondary battery fire suppressant may be positioned on the outer surface, the inner surface, or the inner surface as an intermediate layer of a pouch forming each cell of the secondary battery, and may be included not only on the entire surface of the pouch but also on a portion of the surface of the pouch.

[0100] Additionally, a sheet impregnated with a secondary battery fire suppressant may be applied or attached to the inner surface of a battery pack case that accommodates a secondary battery, or may be sprayed and included inside or outside the battery pack.

[0101] When the secondary battery fire suppressant is decomposed by heat due to thermal runaway of the secondary battery according to an embodiment of the present invention, reactive decomposition gases and cationic metal ions may be generated and emitted.

[0102] The reactive decomposition gas emitted can detoxify the toxic gas emitted from the secondary battery. The reactive decomposition gas emitted by the secondary battery fire suppressant according to the embodiment of the present invention, which is prepared by including one (1) or two (2) or more of carbonate, chloride, hydroxide, or phosphate, decomposes by heat, may be a mixture of one (1) or two (2) or more of carbon dioxide (CO2), chlorine gas, hydroxyl radical, and phosphoric acid gas.

[0103] In addition, cationic metal ions can absorb radicals generated from electrical sparks or flames, thereby preventing a chain reaction of combustion reactions and thus suppressing the chain reaction of fire.

[0104] The carbonate included in the secondary battery fire suppressant according to an embodiment of the present invention may be a secondary battery fire suppressant including at least one of sodium carbonate (Na2CO3), sodium bicarbonate (NaHCO3), potassium carbonate (K2CO3), potassium bicarbonate (KHCO3), ammonium carbonate ((NH4)2CO3), and ammonium bicarbonate (NH4HCO3).

[0105] The chloride salt that may be included in the secondary battery fire suppressant according to an embodiment of the present invention may be a fire suppressant including one (1) or a combination of two (2) or more of ammonium chloride (NH4Cl), potassium chloride (KCl), aluminum chloride (AlCl3), and sodium chloride (NaCl).

[0106] The hydroxide salt that may be included in the secondary battery fire suppressant according to an embodiment of the present invention may be a fire suppressant including one (1) or a combination of two (2) or more of sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca(OH)2), and magnesium hydroxide (Mg(OH)2).

[0107] The phosphate that may be included in the secondary battery fire suppressant according to an embodiment of the present invention may be a fire suppressant including one (1) or two (2) or more of ammonium phosphate ((NH4)3PO4), sodium phosphate (Na3PO4), and potassium phosphate (K3PO4).

[0108]

[0109] An example of mixing carbonate materials among secondary battery fire suppressants can be implemented as shown in Table 5 above.

[0110] Combustible gas COC2H 23 CH4 Sodium Carbonate 55 wt% 10 wt% 10 wt% Potassium Bicarbonate 20 wt% 60 wt% 10 wt% Magnesium Carbonate 5 wt% 10 wt% 70 wt%

[0111] An example of mixing chloride substances among secondary battery fire suppressants can be implemented as in Table 6 above.

[0112] Combustible gas COC2H 23CH4 Ammonium Chloride 30 wt% 20 wt% 20 wt% Potassium Chloride 20 wt% 40 wt% 30 wt% Aluminum Chloride 10 wt% 10 wt% 20 wt%

[0113] An example of mixing hydroxide salts among secondary battery fire suppressants can be implemented as shown in Table 7.

[0114] Combustible gas COC2H 23 CH4 Sodium hydroxide 40 wt% 40 wt% 30 wt% Calcium hydroxide 20 wt% 20 wt% 20 wt% Magnesium hydroxide 10 wt% 10 wt% 20 wt%

[0115] An example of mixing phosphate materials among secondary battery fire suppressants can be implemented as shown in Table 8.

[0116] Combustible gas COC2H 23 CH4 Ammonium Phosphate 20 wt% 40 wt% 30 wt% Potassium Phosphate 20 wt% 10 wt% 20 wt% Calcium Phosphate 10 wt% 10 wt% 10 wt% Magnesium Phosphate 10 wt% 10 wt% 10 wt%

[0117] Here, the carbonate included in the secondary battery fire suppressant according to an embodiment of the present invention may be selected considering the combustible gas. The selection may be made by the secondary battery manufacturer or user, taking into account the usage environment (operating temperature, etc.) of the secondary battery including the secondary battery fire suppressant according to an embodiment of the present invention, or the type of gas determined to be a hazardous combustible gas.

[0118] In other words, depending on the usage or operating environment, the flammable gases that are deemed to be at risk of causing a dangerous fire when using secondary batteries may vary. For example, CO may be considered a gas that can cause a dangerous fire in secondary batteries. In this case, some carbonates may be appropriately selected and used alone or in combination, depending on the flammable gas that could cause a dangerous fire.

[0119] For example, if the combustible gas that can cause a dangerous fire is carbon monoxide (CO), it may contain 55 wt% sodium carbonate, 20 wt% sodium bicarbonate, and 5 wt% magnesium carbonate. The carbonate may be formed by a combination thereof. It may also contain 30 wt% ammonium chloride, 20 wt% potassium chloride, and 10 wt% aluminum chloride. The chloride salt may be formed by a combination thereof. It may also contain 40 wt% sodium hydroxide, 20 wt% calcium hydroxide, and 10 wt% magnesium hydroxide. The hydroxide salt powder may be formed by a combination thereof. It may also contain 20 wt% ammonium phosphate, 20 wt% potassium phosphate, 10 wt% calcium phosphate, and 10 wt% magnesium phosphate. The phosphate may be formed by a combination thereof. Additionally, one or more of the above carbonates, chlorides, hydroxides, or phosphates may be blended.

[0120] Meanwhile, the organic binder (120) can be mixed with a carbonate (121).

[0121] In addition, the organic binder (120) may include one or more of an organic adhesive and an elastomer. Through this, the secondary battery fire suppressant (100) may have any shape.

[0122] Figure 3 is a photograph showing the paste state of a secondary battery fire suppressant according to one embodiment of the present invention.

[0123] As shown in FIG. 3, the secondary battery fire suppressant can be formed into a paste state by mixing with an organic binder (120) including at least one of an organic adhesive and a rubber.

[0124] As a specific example, the secondary battery fire suppressant of FIG. 3 is a mixture of 80 wt% carbonate and 20 wt% soft polyurethane with an organic binder (120).

[0125] A secondary battery fire suppressant in a paste state like this can be applied or coated on the inner surface of a case (corresponding to a battery pack cover (20) when referring to FIG. 5) that accommodates a secondary battery.

[0126] If a fire occurs in a secondary battery and the temperature increases to a temperature range deemed dangerous, each carbonate may sequentially decompose according to its decomposition initiation temperature, releasing carbon dioxide and cationic metal ions.

[0127] This can block oxygen access to combustible gases generated from secondary batteries through the suffocating effect of carbon dioxide. Furthermore, lithium, which can cause ignition, is converted to lithium carbonate, rendering it non-flammable. Furthermore, the spread of fire can be suppressed by absorbing radicals generated by sparks.

[0128] The secondary battery fire suppressant may be provided in the form of an elastic pad.

[0129] In a case where a plurality of secondary batteries are provided, a secondary battery fire suppression pad according to an embodiment of the present invention provided in the form of a pad may be provided positioned between at least one of the plurality of secondary batteries.

[0130] If a fire occurs in a secondary battery, generating heat and reaching a temperature range deemed hazardous, each carbonate in the secondary battery fire suppression pad will sequentially decompose according to its decomposition initiation temperature, releasing carbon dioxide and cationic metal ions. This can suppress or extinguish the fire.

[0131] Meanwhile, if necessary, the secondary battery fire suppressant (100) may further include solid powder.

[0132] FIG. 4 is a photograph showing a secondary battery fire suppression member according to one embodiment of the present invention, and FIG. 5 is an exploded view between layers of a secondary battery fire suppression member according to one embodiment of the present invention.

[0133] As shown in FIGS. 4 and 5, the secondary battery fire suppression member (1000) may include a pair of fiber members (210, 220) and a secondary battery fire suppression member (100).

[0134] A pair of fiber members (210, 220) may be non-combustible fiber members. In addition, a secondary battery fire suppressant (100) may be provided between the pair of fiber members (210, 220).

[0135] In this embodiment, the secondary battery fire suppression member (1000) may be formed by first applying a paste-type secondary battery fire suppression member (100) to one fiber member (220), and then covering the top with another fiber member (210). A coater may be used to coat the paste-type secondary battery fire suppression member (100).

[0136] Alternatively, the secondary battery fire suppression member (1000) may be formed by first forming the secondary battery fire suppression member (100) into a pad shape, and then attaching a pair of fiber members (210, 220) to both sides of the secondary battery fire suppression member pad formed into a pad shape.

[0137] A secondary battery fire suppression member (1000) may be provided to cover at least a portion of a secondary battery. Referring to FIG. 4, the secondary battery fire suppression member (1000) may be provided to cover the battery pack (10) from the inside of the battery pack cover (20).

[0138] Since the secondary battery fire suppression member (1000) can be formed to correspond to the shape of the battery pack (10), it can stably cover the entire battery pack (10).

[0139] When a fire occurs in a secondary battery and the temperature increases to a temperature range deemed dangerous, the carbonate of the secondary battery fire suppression member (1000) sequentially decomposes according to the decomposition initiation temperature, and carbon dioxide and cationic metal ions may be emitted. Through this, the spread of the fire can be suppressed or extinguished.

[0140] As shown in FIG. 5, the secondary battery fire suppression member (1000) may include a pair of fiber members (210, 220), a secondary battery fire suppression member (100), a heating wire (300), and a switch (400).

[0141] A pair of fiber members (210, 220) and a secondary battery fire suppressant (100) may be the same as those described in FIGS. 4 and 5.

[0142] The heating wire (300) may be placed on one of the fiber members (220) among a pair of fiber members (210, 220). The heating wire (300) may be in direct contact with the secondary battery fire suppressant (100). In addition, the heating wire (300) may be connected to the secondary battery (11).

[0143] And, the switch (400) can be connected to the heating wire (3W). In one embodiment, the switch (400) can be connected to the heating wire (300) on the outside of the fiber member (220).

[0144] When the detected temperature exceeds a preset allowable temperature, the switch (400) can cause the current of the secondary battery (11) to be applied to the heating wire (300) arranged in the fiber member (220), and the heating wire (300) can be heated. The heating wire (300) can be heated by Joules. Here, the allowable temperature can be a dangerous temperature requested by the user.

[0145] Therefore, when a fire occurs and the temperature exceeds a dangerous temperature, the current of the secondary battery (11) is applied to the heating wire (300), which may heat the heating wire (300). And, the carbonate may be decomposed by the heat of the heating wire (300).

[0146] At this time, the heating wire (300) can be heated to correspond to the lowest decomposition initiation temperature among the powders included in the extinguishing material, thereby allowing the powder with the lowest decomposition initiation temperature to be decomposed primarily. If the fire is not extinguished through the primary extinguishing process, the temperature will rise, and secondary and tertiary extinguishing processes can then be performed.

[0147] The switch (400) can be configured to allow a permissible temperature to be set according to the dangerous temperature required by the user. This allows the extinguishing process initiation temperature of the secondary battery fire suppression member (1000) to be easily and accurately set according to the dangerous temperature required by each user.

[0148] For example, the switch (400) may be configured to include a bimetal that can automatically implement a switching operation depending on temperature.

[0149] In addition, the secondary battery fire suppression member (1000) may further include a temperature sensor unit (500) for temperature detection. In this case, the switch (400) may be configured to perform a switching operation based on the temperature detected by the temperature sensor unit (500).

[0150] Meanwhile, the secondary battery fire suppression member (1000) is not limited to detecting temperature, and may detect other things. For example, the secondary battery fire suppression member (1000) may detect pressure.

[0151] When pressure is detected as a target, the secondary battery fire suppression member (1000) may further include a pressure sensor unit (not shown).

[0152] The pressure sensor unit can detect the internal pressure of the secondary battery (11).

[0153] When a fire occurs and the internal pressure of the secondary battery (11) increases and the detected pressure exceeds a preset allowable pressure, the switch (400) can cause the current of the secondary battery (11) to be applied to the heating wire (300) arranged in the fiber member (220), and the heating wire (300) can be heated.

[0154] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single entity may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0155] The scope of the present invention is indicated by the claims set forth below, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

[0156]

[0157] [Explanation of symbols]

[0158] 10: Battery pack 11: Secondary battery

[0159] 20: Battery pack cover 100: Secondary battery fire suppressant

[0160] 110: Digestible substances 120: Organic binders

[0161] 210, 220: Fiber member 300: Heating wire

[0162] 400: Switch 500: Temperature sensor part

[0163] 1000: Absence of secondary battery fire suppression

Claims

1. One or more first substances having an initiation temperature of decomposition: and A second material mixed with the first material and binding the first material; The above first material is a fire retardant capable of decomposing and rendering combustible organic compounds non-combustible when the decomposition initiation temperature is reached.

2. In paragraph 1, The above first substance is a digestible substance, The second material is an organic binder, Fire suppressant.

3. In paragraph 2, The above digestive substance comprises two or more digestive substances, A fire retardant wherein the two or more extinguishing substances have two or more different decomposition initiation temperatures and can decompose in stages to render the combustible organic compound non-combustible.

4. In paragraph 1, The above first material is a fire retardant capable of making combustible organic compounds non-combustible, comprising at least one of carbonate, chloride, hydroxide, and phosphate.

5. In paragraph 4, The above carbonate comprises at least one of sodium carbonate (Na2CO3), sodium bicarbonate (NaHCO3), potassium carbonate (K2CO3), potassium bicarbonate (KHCO3), ammonium carbonate ((NH4)2CO3), and ammonium bicarbonate (NH4HCO3), and is a fire retardant capable of making combustible organic compounds non-combustible.

6. In paragraph 4, The above chloride salt contains at least one of ammonium chloride (NH4Cl), potassium chloride (KCl), aluminum chloride (AlCl3), and sodium chloride (NaCl), and is a fire suppressant capable of making combustible organic compounds non-combustible.

7. In paragraph 4, The above hydroxide salt contains at least one of sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca(OH)2), and magnesium hydroxide (Mg(OH)2), and is a fire suppressant capable of making combustible organic compounds non-combustible.

8. In paragraph 4, The above phosphate comprises at least one of ammonium phosphate ((NH4)3PO4), sodium phosphate (Na3PO4), and potassium phosphate (K3PO4), and is a fire retardant capable of making combustible organic compounds non-combustible.

9. In paragraph 2, The above fire suppressant is a fire suppressant provided in one or more of a paste state, a liquid state, and a gaseous state.

10. In paragraph 1, The second material is a fire retardant capable of rendering a combustible organic compound non-combustible, comprising at least one of an organic adhesive and an elastomer.

11. A pair of fiber members; and One or more extinguishing substances provided between a pair of said fiber members, said extinguishing substances having a decomposition initiation temperature and capable of decomposing and rendering combustible organic compounds non-combustible when said decomposition initiation temperature is reached: and A fire suppression member capable of rendering combustible organic compounds non-combustible, comprising a fire suppressant comprising an organic binder mixed with the above-mentioned extinguishing material.

12. One or more extinguishable substances having an onset temperature of decomposition: and An organic binder mixed with the above-mentioned digestible substance; A secondary battery, wherein the above-mentioned extinguishing agent comprises a fire retardant capable of decomposing and rendering non-combustible combustible organic compounds when the decomposition initiation temperature is reached.

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