Laminated composite pad for secondary battery and manufacturing method therefor

Abstract

The present invention relates to a laminated composite pad for a secondary battery and a manufacturing method therefor, wherein the laminated composite pad is for ensuring the safety of a battery pack. The purpose of the present invention is to provide a laminated composite pad for a secondary battery and a manufacturing method therefor, wherein a sandwich-type laminated composite pad comprising a first film, which has at least a predetermined compression rate and thus has the function of cushioning an expansion of the secondary battery, and a second film, which has a heat dissipation function for facilitating heat dissipation, is manufactured to provide a foam-type composite pad with cushioning properties, thereby providing a heat dissipation function for discharging heat that is normally generated, and provide at least a specific compression rate to make it possible to deal with volume expansion / contraction that inevitably occur during the process of using the battery and swelling that occurs over the life of the battery, thus improving the safety of the secondary battery.

Description

Laminated composite pad for secondary batteries and method for manufacturing the same

[0001] The present invention relates to a secondary battery safety pad between secondary battery cells / modules, and to a laminated composite pad for a secondary battery and a method for manufacturing the same, which prevents or delays the spread of a fire occurring in a single cell to surrounding cells in preparation for heat generation / ignition occurring during secondary battery operation, thereby ensuring the safety of a secondary battery pack.

[0002] The lithium secondary battery market has expanded beyond its role as a power source for small mobile electronic devices such as cell phones and laptops, to a power source for electric vehicles for long-distance driving, and to the level of being used as the primary storage source of electric energy in energy storage systems (ESS) that store and use surplus electricity generated through eco-friendly power generation as needed.

[0003] Lithium secondary battery systems based on non-aqueous electrolytes have made rapid progress as high energy / high output has become possible due to high operating voltage.

[0004] However, in lithium secondary battery systems that use flammable organic solvents as electrolytes, there is always a risk of fire accidents due to mechanical and electrical misuse caused by various reasons during battery use.

[0005] In the case of medium- to large-sized battery systems as power sources for electric vehicles, ESS, etc., tens to thousands of single cells are integrated to meet high energy demands.

[0006] To respond to external shocks, cells are assembled into modules by placing them in a frame, and these modules are then assembled into a battery pack.

[0007] In medium- to large-scale systems utilizing packs with a large number of cells, the safety of the battery pack is very important because, in the event of a fire, thermal runaway can spread to surrounding cells, leading to continuous fires and a large-scale fire.

[0008] In this way, when batteries are integrated into a confined space, there is a problem that they are almost in physical contact with the surrounding cells. Therefore, when a fire occurs in a single cell, the possibility of a continuous explosion due to the fire spreading to adjacent cells due to thermal runaway increases rapidly, making it more urgent to ensure safety.

[0009] To minimize material and personal damage from ignition, it is crucial to prevent the spread of thermal runaway and secure evacuation time. One solution to this problem has been the introduction of secondary battery safety composite pads.

[0010] This is based on the insulation function of the safety composite pads located between cells, and in the event of a fire, it prevents or delays the transfer of heat to adjacent cells as much as possible, thereby preventing a chain reaction of explosions, thereby buying time to respond to the fire and minimizing damage.

[0011] The present invention relates to a laminated composite pad for a secondary battery and a method for manufacturing the same, and aims to provide a composite pad for a secondary battery based on flame retardancy and insulation properties, as a method for ensuring safety by effectively minimizing the phenomenon of fire in a single cell occurring from various causes during operation of a secondary battery being transferred to adjacent cells.

[0012] The present invention provides a laminated composite pad for a secondary battery and a method for manufacturing the same, wherein a sandwich-type laminated composite pad is composed of a first film having a compressibility higher than a certain level to have a cushioning function against expansion of a secondary battery, and a second film having a heat dissipation function to facilitate heat dissipation, thereby providing a foam-type composite pad having cushioning properties to provide a heat dissipation function for dissipating heat generated in normal times, and is configured to provide a compressibility higher than a certain level to be able to respond to volume expansion / contraction and swelling according to the lifespan that inevitably occur during the use of a battery, and basically includes flame retardancy and heat insulation properties, thereby improving the safety of a secondary battery.

[0013] The present invention aims to provide a safety composite pad based on flame retardancy and insulation properties, which is positioned between cells or between modules to prevent or delay as much as possible the spread of a fire originating in a single cell to surrounding cells, thereby preventing a chain reaction of fire / explosion leading to a large-scale fire, thereby ensuring the safety of a secondary battery pack, in preparation for heat generation / ignition, etc. that occurs during battery operation, such as in a lithium secondary battery.

[0014] The present invention aims to provide a functional safety composite pad to replace the expansion buffer battery pressure pad currently used for the purpose of preventing pressure increase due to battery swelling, thereby minimizing the reduction in energy density of a battery pack due to the addition of components unrelated to energy generation, and to improve more effective heat transfer prevention performance by directly reducing heat generated by fire through flame retardancy / extinguishing functions as well as expansion buffering and insulation properties.

[0015] The present invention is characterized by a high compression characteristic including a pad characteristic of high compression ratio applied between cells to cope with pressure increase within the current cell, and a laminated composite pad formed in the form of an insulating fire extinguishing foam with expansion buffering characteristics.

[0016] The laminated composite pad for a secondary battery of the present invention is characterized by including a first film having excellent insulating properties for preventing / delaying heat transfer.

[0017] Its technical feature is that by including a flame retardant / extinguishing material in the first film manufacturing process, combustion originating from the battery can be prevented and heat and flame transfer to the surroundings can be minimized through the development of a fire extinguishing function.

[0018] Additionally, the laminated composite pad for secondary batteries must be able to effectively dissipate heat generated inside the battery to the outside during normal operating conditions unrelated to fire.

[0019] That is, even within the normal operating temperature range, slight heat may be generated due to internal battery resistance. If this heat cannot be dissipated externally and accumulates, it can cause battery malfunctions. Therefore, a heat dissipation function that facilitates heat dissipation under normal conditions is required. This is addressed through the use of an additional second film.

[0020] The present invention is characterized by including a second film that provides a heat dissipation function to facilitate heat dissipation.

[0021] In addition, during the process of using the battery, not only does volume change occur according to charging and discharging, but also swelling of the battery occurs due to internal gas generation along with the life of the battery. In order to offset the inevitable increase in pressure inside the module / pack, it is necessary for the safety composite pad to have a buffering function for the expansion of the battery. The technical feature is to manufacture a laminated composite pad having a compression ratio of a certain level or higher by forming a first film and a second film in a laminated form.

[0022] The laminated composite pad for a secondary battery of the present invention is a composite having a laminated structure including a first film having excellent flame retardancy / fire extinguishing and heat insulation properties, and a second film having excellent heat dissipation / fire resistance properties on the outer surface thereof, and can be formed in the form of a foam having cushioning properties.

[0023] In the case of polymer-based materials, when directly exposed to high temperatures, they lose their insulating properties due to cracks caused by rapid expansion / contraction of the polymer, and since the polymer itself is used as fuel during the combustion process, it is difficult for it to maintain its original shape.

[0024] Therefore, the laminated composite pad for secondary batteries of the present invention can increase durability by preventing direct heat transfer to the insulating first film even when the pad is directly exposed to high temperatures through the introduction of a second film with excellent heat resistance characteristics to the outer shell, thereby preventing rapid expansion / contraction due to exposure to high temperatures / extreme heat, thereby preventing cracks caused by this, thereby providing a laminated composite pad capable of maintaining the shape of the first film without loss of insulation / flame retardant function.

[0025] The present invention relates to a laminated composite pad for a secondary battery, which is manufactured by using a second film instead of a release paper, which is essential in the manufacturing process, in the manufacturing of a first film, thereby enabling the formation of a sandwich structure in which the interface between the first and second films is firmly bonded without a separate bonding process.

[0026] The laminated composite pad for a secondary battery of the present invention is characterized by being composed of a sandwich laminate in which a first film made of a polymer resin providing an elastic structure with heat resistance and flexibility, and a second film for providing fire resistance and heat dissipation functions is bonded to the outer surface of the first film, in an insulating fire extinguishing pad for a secondary battery.

[0027] In the laminated composite pad for secondary batteries of the present invention, the first film is characterized in that it is formed by curing a polymer resin mixture applied to the second film and is then adhesively fixed to the second film.

[0028] And in the laminated composite pad for secondary batteries of the present invention, the second film is characterized in that it is made of a fabric sheet composed of inorganic fibers.

[0029] In the laminated composite pad for secondary batteries of the present invention, the first film is characterized by being cured by mixing a (self-foaming) flame retardant material based on a polymer resin.

[0030] And the method for manufacturing the laminated composite pad for secondary battery of the present invention is,

[0031] It is characterized by a process of producing a flame-retardant resin mixture, applying the flame-retardant resin mixture to a fabric sheet, positioning a fabric sheet of the same material on the opposite side of the resin mixture applied to the fabric sheet, casting to a predetermined thickness using a doctor blade, and curing the resin mixture in the fabric sheet at a specific temperature for a predetermined time to manufacture a polymer composite in a foam form.

[0032] At this time, the flame retardant resin mixture may include a polymer resin, a curing agent, a functional flame retardant, a foaming agent, an insulating additive, and an additive for viscosity control.

[0033] According to the present invention, a multifunctional safety composite pad having a foam form that more effectively improves heat transfer prevention performance by directly reducing heat generated by a fire due to the flame retardancy / extinguishing function, by configuring a laminated composite pad comprising a first film providing excellent insulation, flame retardancy, and fire extinguishing functions for preventing / delaying heat transfer, and a second film comprising an inorganic fiber-based fabric sheet providing heat resistance and heat dissipation functions on the outer surface of the first film, thereby preventing combustion of the battery and minimizing heat and flame transfer to the surroundings through the expression of the fire extinguishing function, and by providing an excellent performance insulating fire extinguishing means having a buffering property against swelling and expansion of the battery, can be provided.

[0034] Furthermore, according to the present invention, the second film, which has excellent heat resistance properties, prevents direct heat transfer from the polymer-based material to the first film by preventing the first film from being directly exposed to high temperatures / extreme heat from the outer surface, thereby improving the somewhat low thermal stability inherent in polymer materials, thereby enhancing durability. Accordingly, by enabling the first film to maintain its shape without loss of insulation / flame retardancy due to polymer degradation, it becomes possible to provide a stable composite pad.

[0035] Figure 1 is a cross-sectional view of a laminated composite pad for a secondary battery according to the present invention.

[0036] Figure 2 is a drawing showing the manufacturing process of the laminated composite pad for the secondary battery of the present invention.

[0037] Figure 3 is a drawing showing a boundary surface when a second film is peeled from a first film in the present invention.

[0038] Figures 4a and 4b are drawings showing the expansion behavior during a thermal transfer prevention evaluation test, where Figure 4a shows the first film alone, and Figure 4b shows the sandwich structure of the first film and the second film.

[0039] Figures 5a and 5b are drawings showing the front view of the safety pad after the completion of the thermal transfer prevention evaluation test, where Figure 5a shows the first film alone, and Figure 5b shows the sandwich structure of the first film and the second film.

[0040] First, the terms used in this specification and claims are general terms selected based on their functions in various embodiments of the present invention. However, these terms may vary depending on the intentions of those skilled in the art, legal or technical interpretations, and the emergence of new technologies. Furthermore, some terms may be arbitrarily selected by the applicant. These terms may be interpreted according to the meanings defined herein. In the absence of a specific definition, they may be interpreted based on the overall content of this specification and common technical knowledge in the relevant technical field.

[0041] In addition, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, and therefore, there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0042] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "comprise" or "comprises" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but should be understood not to preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0043] The present invention aims to manufacture a multifunctional safety composite pad in the form of a foam having cushioning properties for a laminated composite pad for a secondary battery.

[0044] The self-foaming foam composite pad for a secondary battery of the present invention forms a sandwich structure in which a second film is formed on both sides of a first film in order to improve the thermal durability of a polymer-based first film.

[0045] Through this, the second film on the outer shell prevents direct contact with the first film from a heat source, thereby maintaining its shape even when exposed to high temperatures / extreme heat, thereby sufficiently demonstrating its performance as a safety composite pad. In addition, the heat dissipation function according to the open structure is configured to immediately discharge the internal heat generated inside the battery during normal times, thereby preventing internal heat accumulation.

[0046] The laminated composite pad for secondary batteries of the present invention is:

[0047] By manufacturing a sandwich laminate by using a second film as a release paper instead of a first film during the first film manufacturing process, it is possible to form a sandwich structure in which the interface between the first and second films is firmly bonded without a separate bonding process.

[0048] According to this, by manufacturing a sandwich laminate by curing a resin composition between the first manufactured second films to form a first film, it is possible to manufacture a secondary battery safety composite pad having a sandwich laminate structure in which the interface between the two films is firmly bonded without a separate process for bonding the two films.

[0049] In this way, the present invention can provide a secondary battery safety composite pad having a sandwich structure in which a second film having heat-resistant functionality is positioned on the outer surface of a first film having insulation / heat-resistant properties.

[0050] That is, a secondary battery safety composite pad in the form of a foam having cushioning properties can be provided by laminating a second film based on a fabric composed of inorganic fibers (e.g., glass fiber, silica fiber, carbon fiber, etc.) characterized by high fire resistance / heat resistance onto the outer surface of a first film characterized by insulation / flame retardancy to form a sandwich structure.

[0051] The laminated composite pad of the present invention is

[0052] A sandwich laminate is composed of a first film made of a polymer resin that provides an elastic structure with heat resistance and flexibility, and a second film made of a fabric sheet that is responsible for improving the heat dissipation and fire resistance properties of the first film under normal conditions, and is bonded to the outer surface of the first film.

[0053] In the present invention, the first film may be a composite pad manufactured by mixing functional materials such as a flame retardant and a foaming agent based on a polymer resin.

[0054] The above polymer resin is composed of a silicone resin, and the silicone resin may be polydimethylsiloxane (PDMS; Poly DiMethyl Siloxane) based on siloxane with excellent heat resistance and flexibility.

[0055] And the second film may be made of a fabric sheet composed of inorganic fibers such as glass fibers, silica fibers, carbon fibers, etc.

[0056] The laminated composite pad of the present invention is as follows:

[0057] By curing a polymer resin mixture between two films to form a first film, the second film is bonded to the outer surface of the first film, and can also perform the role of a release paper required in the polymer curing process of the first film, and can form a sandwich structure in which the interface between the first and second films is firmly bonded without a separate bonding process.

[0058] Hereinafter, a method for manufacturing a laminated composite pad for a secondary battery of the present invention will be specifically described with reference to the embodiments illustrated in the attached drawings, FIG. 1 and FIG. 2.

[0059] Fig. 1 is a drawing showing a cross-section of a laminated composite pad for a secondary battery of the present invention, and Fig. 2 is a drawing showing a manufacturing process of the laminated composite pad for a secondary battery of the present invention.

[0060] The method for manufacturing the laminated composite pad of the present invention is as follows:

[0061] The method may include a process of uniformly mixing a functional flame retardant, a foaming agent, etc. into a silicone resin to create a resin mixture, applying the resin mixture to an inorganic fiber-based fabric sheet, positioning an inorganic fiber-based fabric sheet of the same material on the upper surface of the resin mixture applied to the fabric sheet, casting to a set thickness using a doctor blade, and curing the resin mixture in the fabric sheet at a set temperature for a set period of time to manufacture a polymer composite in the form of a foam.

[0062] An embodiment of the present invention as described above,

[0063] A foam-type laminated composite pad having a sandwich structure in which a first film is formed by curing a silicone resin mixture between the second films using a fabric sheet based on inorganic fibers as a second film, and the second film is formed as an outer shell of the first film can be manufactured.

[0064] The laminated composite pad of the present invention is as follows:

[0065] A resin mixture for producing a first film can be prepared by mixing 10 g of silicone resin and a curing agent, 4 to 8 g of metal hydroxide, and 1 to 2 g of a viscosity-controlling additive in a weight ratio, and stirring at a speed of 100 to 800 rpm for 10 to 120 seconds.

[0066] Here, the resin mixture can be prepared by adding 2 to 5 g of potassium triphosphate (K3PO4), a flame retardant.

[0067] According to this, a resin mixture can be prepared by mixing 10 g of silicone resin and a curing agent, 5 g of calcium hydroxide, and 2 to 5 g of potassium phosphate tribasic in a weight ratio, and stirring as described above.

[0068] Then, the resin mixture manufactured as described above is applied to an inorganic fiber-based fabric sheet, and an inorganic fiber-based fabric sheet of the same material is placed on the surface of the resin mixture to form a resin mixture between the fabric sheets.

[0069] Afterwards, the laminated composite pad can be manufactured by molding it into a set thickness using a doctor blade and curing it at a temperature of 90°C to 150°C for 10 to 240 minutes.

[0070] An embodiment of the present invention as described above,

[0071] The technical feature of the present invention is that the first film is composed of a resin composition using a hydroxide-based self-foaming flame retardant, and the second film is a fabric sheet, and the fabric sheet is formed as the outer shell of the first film made of the resin composition, and the outer shell of the first film is made of a polymer resin responsible for fire extinguishing and thermal runaway delay, and the composite pad is formed as a sandwich laminate of an inorganic fiber fabric sheet for heat dissipation and expansion buffering functions.

[0072] In this way, the embodiment of the present invention comprises a flame retardant first film based on a polymer resin composition by curing a resin mixture within a fabric sheet, and a fabric sheet is bonded to the outer surface of the first film to enable the formation of a laminated sandwich structure in the form of a foam, and comprises a composite having a laminated structure including a first film having excellent flame retardancy / fire extinguishing and insulation properties, a second fabric sheet film having excellent heat dissipation / fire resistance properties, etc., which has a foam form for cushioning properties against battery expansion, thereby providing a safety composite pad for a secondary battery capable of improving the safety of the secondary battery.

[0073] A safety composite pad for a secondary battery can be provided, which can improve the safety of a secondary battery by preventing heat and flame from directly affecting the first film through an outer fabric sheet having excellent heat dissipation / fire resistance properties, thereby improving the somewhat low thermal stability of the first film made of a polymer material.

[0074] The process performed to achieve the present invention is as follows.

[0075] (A). Manufacturing Example 1: Manufacturing of the first film

[0076] As a comparative example, a foam pad was manufactured using only the first film. It contained a curing agent that served as a matrix. 6 g of metal hydroxide was uniformly mixed with 10 g of silicone resin. This mixture was applied to a release paper and then cast to a certain thickness using a doctor blade.

[0077] Afterwards, a polymer composite film in the form of a foam was manufactured by self-foaming during the curing process of the silicone resin in an oven heated to a specific temperature.

[0078] After manufacturing, the release paper was separated and only the manufactured film was used.

[0079] (B). Manufacturing Example 2

[0080] Manufacturing was carried out in the same manner as Manufacturing Example 1, but an inorganic fiber-based fabric sheet was used as the second film instead of the release paper of the first film manufactured in Manufacturing Example 1, so that the entire thickness of the first film was manufactured at the same level, and a foam-type polymer composite film (composite pad) was manufactured in which the second film was positioned as the outer shell of the first film.

[0081] In this case, it was prepared with a second film that can also serve as a release paper to maintain the sandwich laminate structure.

[0082] As a result of attempting to artificially separate the second film from the film obtained through the above manufacturing example 2, as shown in Fig. 3, a part of the first film was separated while still attached to the second film, confirming that a strong bond was formed with the second film during the polymer curing process of the first film.

[0083] As a result, it was confirmed that, through the present invention, it is possible to manufacture a composite pad having excellent adhesive strength at the interface between two films by using a second film instead of a release paper to cure the first film instead of manufacturing each film separately and then bonding them.

[0084] (C). Thermal conductivity evaluation test

[0085] A heat transfer prevention evaluation test using a gas torch was performed to evaluate the improved heat resistance properties. As shown in Figs. 4a and 4b, the foam flame-retardant composite pad was positioned vertically, and the gas torch was placed so that the flame penetrated the composite pad, and the flame was applied at a distance where the flame did not directly touch the composite pad. By doing so, the heat transfer phenomenon to the back of the foam composite pad and the presence of damage to the composite pad itself were observed.

[0086] Figures 4a and 4b are drawings showing the expansion behavior during a thermal transfer prevention evaluation test, where Figure 4a shows the case when the first film is alone, and Figure 4b shows the case when the second film is attached to the surface of the first film in a sandwich structure.

[0087] As a result of conducting a heat transfer prevention evaluation test on the first film alone as in Fig. 4a according to a manufacturing example, it can be observed that the opposite side of the point in contact with the flame swells in the shape of a hemisphere at the beginning of the test, and as in Fig. 5a, cracks are observed at the boundary point with the expanded part after the end of the test, so it can be inferred that the initial volume expansion due to heating was the cause of the decrease in durability.

[0088] On the other hand, as shown in Fig. 4b, when the same test was performed on a sandwich laminated structure in which a second film, which is a manufacturing example, was combined, the pad swelling phenomenon observed in the previous test was not observed, and as shown in Fig. 5b, it was confirmed that the structural heat resistance was improved through the results after the test.

[0089] By forming a sandwich laminate structure by bonding a second film with high fire resistance / heat resistance to both sides of the outer surface of a polymer-based first film responsible for insulation performance, a secondary battery safety composite pad was constructed that maintains high insulation performance while increasing durability against flame and heat.

[0090] The effects that can be obtained through the present invention are summarized as follows.

[0091] (1). Improved thermal properties:

[0092] (a) By introducing a fire / heat resistant second film based on inorganic fiber fabric, the weakness of the polymer-based first film in terms of fire / heat resistance can be supplemented, thereby increasing the thermal durability of the safety composite pad.

[0093] (I) It provides heat dissipation characteristics in the horizontal direction of the pad surface through the dispersion of heat generated inside the battery by the randomly oriented mesh structure unique to the weapon fiber fabric.

[0094] (2). Improvement of physical / chemical properties:

[0095] Performance improvement was possible through the introduction of a safety composite pad outer surface with excellent physical strength, electrical insulation, and decomposition / corrosion resistance unique to inorganic fibers.

[0096] Meanwhile, in the above-described embodiment of the present invention, the first film of the polymer foam using the foamable flame retardant is formed using a resin composition based on the polymer resin hydroxide-based self-foaming flame retardant calcium hydroxide (Ca(OH)2), but the first film can be manufactured based on a flame retardant resin composition of another component providing an insulating / flame retardant function, and as an embodiment, the first film can be manufactured using a flame retardant resin composition of a silicone-based resin, decabromodiphenylethane (DBDPE), and calcium carbonate (CaCO3).

[0097] In addition, the first film can be manufactured in the form of a foam having a pore structure with expansion buffering properties by mixing an additional blowing agent into a flame-retardant resin mixture containing a siloxane-based silicone resin with excellent heat resistance and flexibility, a halogen-based flame retardant, and an inorganic metal compound flame retardant.

[0098] In the above, a foam composite pad composed of a first film of a resin mixture based on a hydroxide-based self-foaming flame retardant and a second film of a fabric sheet on the outside thereof, a manufacturing method and evaluation results thereof have been presented and described with respect to a preferred embodiment of the present invention. However, the present invention is not limited to the specific embodiment described above, and various modifications can be made by a person skilled in the art to which the present invention pertains without departing from the gist of the present invention claimed in the claims, and such modifications should not be individually understood from the technical idea or prospect of the present invention.

Claims

1. In the insulating fire extinguishing pad for secondary batteries, A laminated composite pad for a secondary battery, comprising a sandwich laminate in which a first film made of a polymer resin providing an elastic structure with heat resistance and flexibility and a second film for providing fire resistance and heat dissipation functions are bonded to the outer shell of the first film.

2. A laminated composite pad for a secondary battery, wherein in the first paragraph, the first film is a mixture based on a polymer resin and a flame retardant material is cured while being applied to the second film and is adhered and fixed to the second film.

3. A laminated composite pad for a secondary battery, wherein the second film is made of a fabric sheet composed of inorganic fibers, in the first or second paragraph.

4. A method for manufacturing a laminated composite pad for a secondary battery, comprising the steps of forming a flame-retardant resin mixture based on a polymer resin and a flame retardant, applying the flame-retardant resin mixture to a fabric sheet, positioning a fabric sheet of the same material on the opposite side of the resin mixture applied to the fabric sheet, casting to a set thickness, and hardening the resin mixture in the fabric sheet at a set temperature for a set period of time to manufacture a foam-type pad.

5. A method for manufacturing a laminated composite pad for a secondary battery, characterized in that in the fourth paragraph, the fabric sheet is a fabric sheet based on inorganic fibers.

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