Heat storage, heat absorption and heat insulation material for multifunctional lithium battery and production method of heat storage, heat absorption and heat insulation material

Abstract

The invention belongs to the technical field of lithium batteries, and discloses a multifunctional lithium battery heat storage, heat absorption and heat insulation material which comprises an outer film composed of an upper layer sealing film and a lower layer sealing film, a core material and a phase change material are packaged in the outer film, the outer film is a composite film of one or more of an aluminum plastic film, a pet film, a pi film and a pet-pp film, and the outer film is a composite film of one or more of an aluminum plastic film, a pet film, a pi film and a pet-pp film. The core material is a composite material of one or more of a thermal insulation material, a flame-retardant material or an infrared shielding material; a flame impact resistant material layer and a vibration absorbing material layer are further arranged on the outer side of the outer film. According to the scheme, the heat storage, heat absorption and heat insulation material composed of the outer film, the middle-layer core material and the phase change material has the functions of low-temperature heat storage, medium-temperature heat absorption and high-temperature heat insulation, and compared with aerogel, heat spreading can be effectively blocked.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and more specifically to a heat storage, heat absorption and insulation material for multifunctional lithium batteries and a production method thereof. Background Art

[0002] As markets such as mobile devices and electric vehicles continue to expand, lithium batteries have become an important way to store and convert energy. However, a large amount of heat is generated during the use of lithium batteries. If it cannot be discharged or absorbed in time, it will affect the performance and life of the battery.

[0003] At present, some lithium batteries have adopted heat storage, heat absorption and insulation materials to achieve heat control and regulation. These materials can absorb the heat generated inside the battery and release it when needed, thereby keeping the battery temperature stable. At the same time, they can also isolate the heat exchange between the battery and the outside world, preventing the external environment from affecting the battery performance.

[0004] However, existing heat storage, heat absorption and insulation materials still have some problems. For example, some materials have low heat storage and release efficiency and cannot meet the requirements of high-temperature fast charging of lithium batteries; some materials have high preparation costs and cannot be used on a large scale.

[0005] In the prior art, aerogel felt is usually used for thermal insulation of lithium batteries. However, aerogel only has thermal insulation capability but no ability to store or absorb heat. After thermal runaway of the battery cell, a large amount of heat is simply dissipated by insulation, and the function of suppressing the spread of heat cannot be achieved. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a multifunctional heat storage, heat absorption and insulation material for lithium batteries and a production method.

[0007] To achieve the above object, the present invention adopts the following technical solution.

[0008] A multifunctional heat storage, heat absorption and heat insulation material for lithium batteries, comprising an outer film composed of an upper sealing film and a lower sealing film, wherein a core material and a phase change material are encapsulated in the outer film;

[0009] The outer film is a composite film of one or more of aluminum-plastic film, PET film, PI film, and PET-PP film, and the core material is a composite material of one or more of heat-insulating material, flame-retardant material, or infrared shielding material.

[0010] As a further description of the above technical solution: a flame-resistant impact material layer and a shock-absorbing material layer are also provided on the outside of the outer film.

[0011] As a further description of the above technical solution: the phase change material is in liquid, gel or solid state.

[0012] As a further description of the above technical solution: the phase change material is one or a combination of waxy materials, crystalline hydrated salts, molten salts, liquid metals, and alloys.

[0013] As a further description of the above technical solution: the core material includes glass fiber, ceramic fiber, aerogel, heat reflective material and a combination thereof.

[0014] As a further description of the above technical solution: the porosity of the core material ranges from 89% to 99%, the phase change temperature range of the phase change material is from 85° C. to 200° C., and the heat absorption capacity of the phase change material is from 500 to 3000 J / g.

[0015] As a further description of the above technical solution: the thickness of the core material is 1-5 mm ± 0.1 mm, the density of the core material is 1.1-1.6 g / ml, and the thermal conductivity of the core material is 0.02-0.36 w / m 2 K.

[0016] As a further description of the above technical solution: an inner sealing structure connecting the upper sealing film and the lower sealing film is arranged on the outer film, and the inner sealing structure includes inner sealing structures of other shapes such as a cross frame inner sealing, a circular frame inner sealing, an X-shaped frame inner sealing, a multi-strip frame inner sealing, and a ring frame inner sealing.

[0017] Another technical problem to be solved by the present invention is to provide a method for producing a multifunctional heat storage, heat absorption and heat insulation material for lithium batteries, comprising the following steps:

[0018] Step ①, sealing film stamping: stamping the upper and / or lower sealing films;

[0019] Step ②, placing the core material: placing the core material on the lower sealing film;

[0020] Step ③, assembling and heat-sealing three sides: placing the upper sealing film on the top of the core material, and heat-sealing three sides of the upper and lower sealing films;

[0021] Step ④, adding phase change material: after sealing three sides, leave the remaining side open, and inject phase change material into the film bag to make the overall quality reach the target value;

[0022] Step 5: Seal the last side and cut off the excess

[0023] As a further description of the above technical solution: After the phase change material is injected in step 4④, the outer film is lightly pressed and flattened with a steel plate.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] 1. This solution is a heat storage, heat absorption and insulation material composed of outer film + middle layer core material + phase change material. It has the functions of low-temperature heat storage, medium-temperature heat absorption and high-temperature heat insulation. Compared with aerogel, it can effectively block the spread of heat.

[0026] 2. This solution improves the overall pressure resistance of the material by setting an inner sealing structure on the sealing film, thereby achieving the purpose of pressure resistance.

[0027] 3. The production method of heat storage, heat absorption and insulation materials for lithium batteries provided in this scheme is simple to operate and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the present invention;

[0029] Figure 2 This is the experimental diagram of aerogel heat spread inhibition;

[0030] Figure 3 This is a heat spreading inhibition experiment diagram of the heat storage, heat absorption and heat insulation material of the present invention;

[0031] Figure 4 It is a structural schematic diagram of the cross frame inner sealing structure of the present invention;

[0032] Figure 5 It is a structural schematic diagram of the inner sealing structure of the return frame of the present invention;

[0033] Figure 6 A schematic diagram of the structure of the X-shaped frame inner seal of the present invention;

[0034] Figure 7 A schematic structural diagram of the strip frame inner seal of the present invention;

[0035] Figure 8 A schematic structural diagram of the annular frame inner seal of the present invention.

[0036] Description of the numbers in the figure:

[0037] 1. Upper sealing film; 2. Lower sealing film; 3. Core material; 4. Flame impact resistant material layer; 5. Vibration absorbing material layer; 6. Inner sealing structure. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0039] Embodiment 1

[0040] See also Figure 1A multifunctional heat storage, heat absorption and insulation material for lithium batteries, comprising an outer film composed of an upper sealing film 1 and a lower sealing film 2, wherein a core material 3 and a phase change material are encapsulated in the outer film; the outer film is a composite film of one or more of aluminum-plastic film, PET film, PI film and PET-PP film, and the core material 3 is a composite material of one or more of heat insulation material, flame retardant material or infrared shielding material.

[0041] The core material 3 and phase change material in the middle layer can store heat at low temperature, absorb heat at medium temperature, and insulate heat at high temperature. In the low temperature range, Q = Cp*m*ΔT, the material has a certain heat absorption capacity. In the medium temperature range, when the material changes phase, hβ-hα = △h, the material has a certain heat absorption capacity. In the high temperature range, the thermal conductivity of the material is low, and it has a certain insulation capacity.

[0042] Experimental example

[0043] The heat storage and heat absorption insulation material (abbreviated as: YSD) prepared in this scheme was subjected to a heat spread inhibition experiment with aerogel. Figure 2 , 3 ;

[0044] From the above figure, we can see that:

[0045] Insulation Materials thickness Bat1-Bat2 heat spread time Bat2-Bat3 heat spread time Aerogel 2mm 655S 1006S YSD 1.75 Not spread Not spread

[0046] In summary, the heat storage, heat absorption and heat insulation material of this scheme can effectively block the spread of heat compared with aerogel.

[0047] Furthermore, the outer side of the outer film is also provided with a flame-resistant impact material layer 4 and a vibration-absorbing material layer 5. The flame-resistant impact material includes: mica board, mica paper, siliceous refractory material, aluminosilicate refractory material, magnesia refractory material, dolomite product, chromium product, carbon product, zirconium product.

[0048] Vibration absorbing materials include: nitrile rubber, foam, silicone foam, polyurethane elastomer, polyvinyl chloride, polyethylene oxide-styrene block copolymer, plasticized polyvinyl chloride, polyvinyl butyral, polymethyl methacrylate, vinyl chloride-vinyl acetate copolymer, polyvinyl chloride blends, semi-interpenetrating network type ethylene propylene ternary and ethylene propylene binary rubbers, interpenetrating network type polyisobutyl ether and polymethyl acrylate.

[0049] Phase change materials are in liquid, gel or solid state. Phase change materials are one or a combination of wax materials, crystalline hydrated salts, molten salts, liquid metals, and alloys. The phase change temperature range of phase change materials is 85-200°C, and the heat absorption capacity of phase change materials is 500-3000J / g. Among them, composite phase change materials have more functional advantages: they store heat at low temperatures of 25-85°C, absorb heat at medium temperatures of 90-150°C, and insulate at high temperatures of 200-1200°C.

[0050] The core material 3 includes glass fiber, ceramic fiber, aerogel, heat reflective material and a combination thereof. The porosity of the core material 3 ranges from 89% to 99%. The thickness of the core material 3 is 1-5 mm ± 0.1 mm, the thinnest thickness is 1 mm ± 0.1 mm, and the recommended thickness is 2.0 mm ± 0.1 mm. The density of the core material 3 is 1.1-1.6 g / ml. The thermal conductivity of the core material 3 is 0.02-0.36 w / m 2 K. For example, when the thickness is 2.0 mm, the thermal conductivity is 0.25 w / m 2 K, when the thickness is 1.5mm, the thermal conductivity is 0.36w / m 2 K.

[0051] In addition, if Figure 4-8 As shown, an inner sealing structure 6 connecting the upper sealing film 1 and the lower sealing film 2 is provided on the outer film, and the inner sealing structure 6 includes inner sealing structures of other shapes such as a cross frame inner seal, a circular frame inner seal, an X-shaped frame inner seal, a strip frame inner seal, and a ring frame inner seal, which are not described in detail here. The specific shape structure can be set according to needs, and the pressure resistance is solved by the inner sealing structure 6 to improve the pressure resistance.

[0052] It should be noted that the size of the heat storage, heat absorption and insulation material varies with the size of the battery cell; the thickness of the product can be designed and adjusted according to demand.

[0053] Embodiment 2

[0054] A method for producing a heat storage, heat absorption and heat insulation material for a multifunctional lithium battery comprises the following steps:

[0055] Step ①, sealing film stamping: stamping the upper and / or lower sealing films. It should be noted that the stamping of the upper and lower sealing films depends on the specific situation;

[0056] Step ②, placing the core material: placing the core material 3 on the lower sealing film 2;

[0057] Step ③, assembling and heat-sealing three sides: placing the upper sealing film 1 on the core material 3, and heat-sealing the three sides of the upper and lower sealing films;

[0058] Step ④, adding phase change material: after sealing three sides, leave the remaining side open, and inject phase change material into the film bag to make the overall quality reach the target value;

[0059] Step 5: Seal the last side and cut off the excess

[0060] Step 4 ④ After injecting the phase change material, use a steel plate to gently press the outer film to make it flat.

[0061] The above is only a preferred specific implementation of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved conception within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A multifunctional heat storage, heat absorption and heat insulation material for lithium batteries, characterized in that: It comprises an outer film composed of an upper sealing film (1) and a lower sealing film (2), wherein a core material (3) and a phase change material are encapsulated in the outer film; The outer film is a composite film of one or more of aluminum-plastic film, PET film, PI film, PET-PP film, and the core material (3) is a composite material of one or more of heat-insulating material, flame-retardant material, or infrared shielding material.

2. The multifunctional heat storage, heat absorption and heat insulation material for lithium battery according to claim 1, characterized in that: A flame-resistant impact material layer (4) and a shock-absorbing material layer (5) are also provided on the outside of the outer film.

3. The multifunctional heat storage, heat absorption and heat insulation material for lithium battery according to claim 1, characterized in that: The phase change material is in liquid, gel or solid state.

4. The multifunctional heat storage, heat absorption and heat insulation material for lithium battery according to claim 3, characterized in that: The phase change material is one or a combination of waxy materials, crystalline hydrated salts, molten salts, liquid metals, and alloys.

5. The multifunctional heat storage, heat absorption and heat insulation material for lithium battery according to claim 1, characterized in that: The core material (3) comprises glass fiber, ceramic fiber, aerogel, heat reflective material and a combination thereof.

6. The multifunctional heat storage, heat absorption and heat insulation material for lithium battery according to claim 1, characterized in that: The porosity of the core material (3) is in the range of 89%-99%, the phase change temperature range of the phase change material is 85-200° C., and the heat absorption capacity of the phase change material is 500-3000 J / g.

7. The multifunctional heat storage, heat absorption and heat insulation material for lithium battery according to claim 1, characterized in that: The thickness of the core material (3) is 1-5 mm ± 0.1 mm, the density of the core material (3) is 1.1-1.6 g / ml, and the thermal conductivity of the core material (3) is 0.02-0.36 w / m 2 K.

8. The multifunctional heat storage, heat absorption and heat insulation material for lithium battery according to claim 1, characterized in that: The outer film is provided with an inner sealing structure (6) connecting the upper sealing film (1) and the lower sealing film (2), and the inner sealing structure (6) includes a cross frame inner seal, a circular frame inner seal, an X-shaped frame inner seal, a multi-strip frame inner seal, and a ring frame inner seal.

9. A method for producing a multifunctional heat storage, heat absorption and heat insulation material for lithium batteries according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step ①, sealing film stamping: stamping the upper and / or lower sealing films; Step ②, placing the core material: placing the core material (3) on the lower sealing film (2); Step ③, assembling and heat-sealing three sides: placing the upper sealing film (1) on the core material (3), and heat-sealing three sides of the upper and lower sealing films; Step ④, adding phase change material: after sealing three sides, leave the remaining side open, and inject phase change material into the film bag to make the overall quality reach the target value; Step 5: Seal the last side and cut off the excess part.

10. The method for producing a multifunctional heat storage, heat absorption and heat insulation material for lithium batteries according to claim 9, characterized in that: After the phase change material is injected in step 4 (4), the outer film is lightly pressed and flattened with a steel plate.

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