Heat insulation assembly, safety battery, battery assembly and electronic equipment

Abstract

The utility model provides a heat insulation assembly and application, the heat insulation assembly comprises a heat insulation layer and a heat absorbent, the heat insulation layer comprises a hole structure, and the heat absorbent is filled in at least part of the hole structure of the heat insulation layer; the heat insulation layer is fibrofelt reinforced aerogel, the heat conductivity coefficient of the fibrofelt reinforced aerogel at the temperature of 25 DEG C is smaller than or equal to 0.025 W / mK, and the heat conductivity coefficient of the fibrofelt reinforced aerogel at the temperature of 300 DEG C is smaller than or equal to 0.075 W / mK; the heat absorbent is a gel-state heat absorbent or a liquid-state heat absorbent, heat absorbed by the heat absorbent can be converted into gas, and the enthalpy value of the heat absorbent is larger than or equal to 1200 J / g. According to the heat insulation assembly disclosed by the utility model, the heat absorbent with a high phase change enthalpy value is filled in the hole structure of the heat insulation layer with a low heat conductivity coefficient, so that when the battery cell or the battery is subjected to thermal runaway, the heat absorbent is quickly gasified to absorb a large amount of heat in a system, and the battery cell or the battery is quickly cooled; and the residual heat insulation layer can still show good heat insulation performance even at a high temperature, so that effective protection on adjacent battery cells or batteries is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of heat insulation components, especially a kind of heat insulation components, safe battery, battery assembly and electronic equipment, belong to battery technical field. BACKGROUND

[0002] With the continuous development of electric vehicles and energy storage systems, the demand for secondary batteries as energy storage and conversion components is rapidly increasing. Since secondary batteries need to be used continuously for a long time, it can cause the accumulation of heat inside the battery, and then lead to the occurrence of thermal runaway. When a battery unit of a battery module experiences thermal runaway, the temperature rise will trigger a series of exothermic chemical reactions, causing the ambient temperature around the battery unit to rise, thereby causing the adjacent battery cells to explode and burn, and even possibly causing a fire or a larger explosion.

[0003] Existing research has shown that setting a heat insulation component between battery units can block the heat generated by the thermal runaway battery, reducing the ambient temperature of adjacent battery units, thereby preventing the entire battery module from exploding and other safety incidents caused by overheating of a battery unit. The existing heat insulation component also includes a solid heat absorber that can vaporize at high temperatures and then absorb the heat emitted when the battery experiences thermal runaway. Despite this, the existing heat insulation component has limited heat blocking and absorption, and still cannot effectively protect adjacent battery units. SUMMARY

[0004] To solve the above problems, the utility model provides a kind of heat insulation components, including heat insulation layer and fill in the gel state or liquid heat absorber in the at least partial pore structure of heat insulation layer. Heat insulation layer can keep low thermal conductivity at normal temperature and high temperature environment, effectively reduce heat diffusion efficiency;At the same time, thanks to the high enthalpy of heat absorber, it can quickly vaporize and absorb a large amount of heat when the battery experiences thermal runaway. It can effectively control the spread of thermal runaway risk.

[0005] The utility model also provides a kind of safe battery, including the safe battery cell that the above-mentioned heat insulation component is arranged adjacent to in battery cell matrix. The arrangement of heat insulation component not only can block the heat released by battery cell matrix in normal working state, but also can effectively absorb and block the heat generated by the battery cell matrix when a certain battery cell matrix experiences thermal runaway, thereby avoiding causing adjacent battery cell matrix to overheat and fail in high temperature environment.

[0006] The utility model also provides a kind of battery assembly comprising the above-mentioned heat insulation component, which can prevent heat from being transferred to adjacent batteries when a single battery experiences thermal runaway, and cause consecutive thermal runaway of adjacent batteries.

[0007] The utility model discloses still provide a kind of electronic equipment, including above-mentioned safety battery or above-mentioned battery component. Due to the existence of heat insulation component in safety battery or battery component, the probability of chain explosion combustion caused by adjacent battery cell or battery thermal runaway can be effectively reduced, thereby improving the safety and reliability of electronic equipment.

[0008] The utility model discloses a kind of heat insulation components, including heat insulation layer and heat absorber, the heat insulation layer includes hole structure, the heat absorber is filled in at least part hole structure of the heat insulation layer;

[0009] The heat insulation layer is fiber felt reinforced aerogel, the thermal conductivity of the fiber felt reinforced aerogel is ≤0.025W / mK at 25 ℃, and the thermal conductivity is ≤0.075W / mK at 300 ℃;

[0010] The heat absorber is gel state heat absorber or liquid state heat absorber, and the heat absorber absorbs heat and converts into gaseous state, and the enthalpy of the heat absorber is ≥1200J / g.

[0011] The heat insulation component as described above, wherein the enthalpy of the heat insulation component is ≥400J / g;And / or,

[0012] The thermal conductivity of the heat insulation component is less than 0.8W / mK before phase change.

[0013] The heat insulation component as described above, wherein the density of the heat insulation component is 200-1000Kg / m 3 .

[0014] The heat insulation component as described above, wherein the hole structure is through hole, and the heat absorber is completely filled in the through hole.

[0015] The heat insulation component as described above, wherein, further including heat absorption layer, the heat absorption layer covers at least one surface of the heat insulation layer, and the heat absorption layer is connected with the heat absorber in the hole structure;The heat absorption layer includes the heat absorber.

[0016] The heat insulation component as described above, wherein the total thickness of the heat insulation component is d, the thickness of the heat insulation layer is d1, and 0.5≤d1 / d≤1 is satisfied.

[0017] The heat insulation component as described above, wherein the mass ratio of the heat insulation layer and the heat absorber is (0.1-2):1.

[0018] The heat insulation component as described above, wherein the contact angle of the heat insulation layer with water is ≤90 °.

[0019] The thermal insulation assembly as described above, wherein the thermal insulation layer is at least one of glass fiber mat reinforced aerogel, ceramic fiber reinforced aerogel, pre-oxidized fiber mat reinforced aerogel, aramid fiber mat reinforced aerogel.

[0020] The thermal insulation assembly as described above, wherein the aerogel component of the thermal insulation layer is at least one of silica aerogel and / or alumina aerogel.

[0021] The thermal insulation assembly as described above, wherein the freezing point of the heat-absorbing agent is ≤-20℃.

[0022] The thermal insulation assembly as described above, wherein the gel state heat-absorbing agent comprises at least one of water gel heat-absorbing agent, alcohol gel heat-absorbing agent, and water-alcohol mixed gel.

[0023] Or, the liquid state heat-absorbing agent comprises liquid water and / or a mixed solution of liquid water and alcohol.

[0024] The thermal insulation assembly as described above, wherein the liquid content in the gel state heat-absorbing agent is ≥50%.

[0025] The thermal insulation assembly as described above, wherein the thermal insulation assembly further comprises an encapsulation layer, and the encapsulation layer comprises an encapsulation cavity, and the thermal insulation assembly is encapsulated in the encapsulation cavity.

[0026] The thermal insulation assembly as described above, wherein the material of the encapsulation layer comprises one of PET film, PI film, aluminum plastic film, aluminum alloy foil, steel foil, aluminum strip, and steel strip.

[0027] The utility model discloses a second aspect provides a kind of safety battery, including safety battery and encapsulation structure, the safety battery includes battery core matrix and the first aspect described thermal insulation assembly being adjacently arranged with the battery core matrix;The safety battery is encapsulated in the encapsulation cavity of the encapsulation structure.

[0028] The utility model discloses a third aspect provides a kind of battery assembly, the battery assembly includes adjacent battery, and the adjacent battery between including the first aspect described thermal insulation assembly.

[0029] The battery assembly as described above, wherein the battery comprises a battery core and an encapsulation structure, the battery core comprises a battery core matrix and the first aspect described thermal insulation assembly being adjacently arranged with the battery core matrix;The battery core is encapsulated in the encapsulation cavity of the encapsulation structure.

[0030] The utility model discloses a fourth aspect provides a kind of electronic equipment, including as the safety battery of second aspect, or the battery assembly of third aspect.

[0031] The heat insulation assembly provided by the utility model fills the heat-absorber with high phase change enthalpy in the low-thermal-conductivity heat insulation layer hole structure, when the electric core or the battery is in thermal runaway, the heat-absorber is first converted from the gel state or the liquid state into the gaseous state, absorbs a large amount of heat in the system, rapidly cools the electric core or the battery, and reduces the heat emitted by the thermal runaway of the electric core or the battery to the surrounding environment; after the heat-absorber is completely gasified, the remaining heat insulation layer can still exhibit good heat insulation performance under high temperature, thereby realizing effective protection of the adjacent electric core. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a top view schematic diagram of one embodiment of the heat insulation assembly of the utility model;

[0033] Figure 2 It is a front view schematic diagram of one embodiment of the heat insulation assembly of the utility model;

[0034] Figure 3 It is a front view schematic diagram of one embodiment of the heat insulation assembly of the utility model;

[0035] Figure 4 It is a schematic diagram of one embodiment of the safety battery of the utility model.

[0036] EXPLANATION OF REFERENCE NUMERALS:

[0037] 1-heat insulation layer;

[0038] 2-hole structure;

[0039] 3-heat-absorbing layer;

[0040] 4-heat insulation assembly;

[0041] 5-first electric core base body;

[0042] 6-second electric core base body. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the utility model more clear, the technical scheme in the embodiments of the utility model will be clearly and completely described below in combination with the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor belong to the protection scope of the utility model.

[0044] Figure 1 It is a top view schematic diagram of one embodiment of the heat insulation assembly of the utility model, as shown in Figure 1 The utility model provides a kind of heat insulation assembly, including heat insulation layer 1 and heat-absorber, heat insulation layer 1 includes hole structure 2, heat-absorber is filled in at least part of hole structure 2 of heat insulation layer 1;

[0045] The thermal insulation layer 1 is a fiber felt reinforced aerogel, and the thermal conductivity of the fiber felt reinforced aerogel is ≤0.025 W / mK at 25℃ and ≤0.075 W / mK at 300℃.

[0046] The heat-absorbing agent is a gel or liquid heat-absorbing agent, and the heat-absorbing agent is converted into a gaseous state after absorbing heat, and the enthalpy of the heat-absorbing agent is ≥1200 J / g.

[0047] In the utility model, the thermal insulation layer 1 realizes the heat blocking by the low thermal conductivity; the heat-absorbing agent can absorb heat by phase change, and the liquid or gel heat-absorbing agent is beneficial to the uniform filling and distribution in the hole structure 2 of the thermal conductivity layer, so that the heat generated by each part of the battery can be effectively absorbed.

[0048] The thermal insulation assembly of the utility model is applied between adjacent battery cells or batteries, and can effectively absorb and insulate the heat of the battery cells or batteries in thermal runaway. The thermal conductivity of the commonly used thermal insulation layer such as glass fiber felt is at least 0.030 W / mK at room temperature, and the thermal conductivity of the glass fiber felt further increases greatly when the ambient temperature reaches 300°C, and the thermal insulation effect is poor, which is insufficient to block the heat generated by the battery in thermal runaway. In addition, most solid heat-absorbing agents are not only inconvenient to be compounded with the thermal insulation layer to form a uniform heat-absorbing layer, but also have a phase change enthalpy of less than 300 J / g, and the heat-absorbing effect is very limited. The utility model adopts the fiber felt reinforced aerogel thermal insulation layer 1 with low thermal conductivity and the liquid or gel heat-absorbing agent with high enthalpy. When the battery cell or battery is in thermal runaway, the heat-absorbing agent is converted from a gel or liquid state to a gaseous state, and a large amount of heat in the system is absorbed, so that the battery cell or battery is rapidly cooled, and the heat emitted to the surrounding environment by the battery cell or battery in thermal runaway is reduced. When the heat-absorbing agent is completely gasified, the remaining thermal insulation layer 1 still has good thermal insulation performance at a relatively high temperature, and the adjacent battery cell is effectively protected.

[0049] Figure 2 It is a front view schematic diagram of an embodiment of the thermal insulation assembly of the utility model, Figure 2 In the utility model, the heat-absorbing agent is filled in the hole structure 2 of the thermal insulation layer 1, and the thickness of the thermal insulation assembly is d.

[0050] In a specific embodiment, the enthalpy of the thermal insulation assembly is ≥400 J / g. Under the premise of ensuring the good thermal insulation effect of the thermal insulation assembly, the amount of the heat-absorbing agent and the thermal insulation layer 1 is controlled to ensure that the thermal insulation assembly can absorb most of the heat generated by the battery in thermal runaway.

[0051] The thermal conductivity of the heat insulation assembly before phase change is less than 0.8 W / mK, which can ensure that the heat insulation effect is maintained after the heat absorption agent is completely gasified, the heat transferred from the battery in thermal runaway to the surrounding environment is reduced, and the adjacent battery cells or batteries are protected.

[0052] The thermal conductivity of the heat insulation assembly before phase change in the utility model can be obtained by testing with a hot-wire method thermal conductivity instrument, and the testing method is in accordance with GB / T 10297 "Determination of Thermal Conductivity of Nonmetallic Solid Materials - Hot-Wire Method".

[0053] The density of the heat insulation assembly is controlled to be 200-1000 Kg / m 3 The filling effect of the heat absorption agent in the heat insulation layer 1 can be indirectly controlled, the heat insulation and heat absorption effects of the heat insulation assembly are balanced, the temperature of the adjacent battery cells or batteries is reduced as much as possible, and the heat propagation is reduced.

[0054] In addition, the heat insulation layer 1 and the heat absorption agent of the through-hole structure 2 can be selected to form a heat insulation assembly, the heat absorption agent is completely filled in the through hole, the heat absorption effect of the heat insulation assembly can be enhanced, and the probability of thermal runaway chain reaction is effectively reduced.

[0055] Figure 3 It is a front view schematic diagram of an embodiment of the heat insulation assembly of the utility model, referring to Figure 3 In order to enhance the heat absorption and cooling effect of the battery system, the heat insulation assembly of the utility model can further include a heat absorption layer 3 containing the heat absorption agent, the heat absorption layer 3 covers at least one surface of the heat insulation layer 1, and the heat absorption layer 3 is connected with the heat absorption agent in the hole structure 2. At this time, the thickness d of the heat insulation assembly is the sum of the thickness of the heat insulation layer 1 and the thickness of the heat absorption layer 3.

[0056] Therefore, further, the thickness of the heat insulation layer 1 and the heat absorption layer 3 in the heat insulation assembly can be controlled, so that the total thickness d of the heat insulation assembly and the thickness d1 of the heat insulation layer 1 satisfy 0.5≤d1 / d<1. If d1 / d<0.5, the heat insulation effect of the heat insulation layer 1 after the phase change of the heat absorption layer 3 is not ideal.

[0057] Further, the mass ratio of the heat insulation layer and the heat absorption agent can be controlled to be (0.1-2):1, and better heat absorption and heat insulation effects can be obtained at the same time.

[0058] In the heat insulation assembly of the utility model, the good hydrophilicity of the heat insulation layer 1 is beneficial to reduce the surface tension of the heat absorption layer on the heat insulation layer 1, promote the good spreading of the heat absorption layer, and then realize the uniform filling of the heat absorption layer in the hole structure 2 of the heat insulation layer 1. Therefore, the contact angle between the heat insulation layer 1 and water can be controlled to be ≤90°.

[0059] Specifically, the thermal insulation layer 1 of the thermal insulation assembly can select at least one of glass fiber felt reinforced aerogel, ceramic fiber reinforced aerogel, pre-oxidized fiber felt reinforced aerogel and aramid fiber felt reinforced aerogel.

[0060] Further, the silica aerogel and / or the alumina aerogel has extremely low thermal conductivity, high temperature resistance, excellent fireproof performance and other advantages, so the aerogel component of the thermal insulation layer 1 can select silica aerogel and / or alumina aerogel.

[0061] Considering the possibility that the battery can be used in a cold environment, the freezing point temperature of the endothermic agent of the thermal insulation assembly can be controlled to be ≤-20℃, so as to avoid the endothermic agent from freezing in a low temperature environment and affect the endothermic effect of the thermal insulation assembly.

[0062] Further, the freezing point temperature of the endothermic agent can also be controlled to be below-40℃, so that the thermal insulation assembly can be used in extremely cold regions.

[0063] In a specific embodiment, the gel state endothermic agent includes at least one of a hydrogel endothermic agent, an alcohol gel endothermic agent and a water-alcohol mixed gel, or the liquid state endothermic agent includes liquid water and / or a mixed solution of liquid water and alcohol.

[0064] Further, the gel state endothermic agent with a liquid content ≥50% can be selected, so that the endothermic agent maintains a high enough enthalpy value, thereby achieving better cooling effect on the environment around the thermal runaway battery.

[0065] In the utility model, the "liquid content" refers to the mass percentage content of water and / or alcohol in the gel state endothermic agent.

[0066] The utility model does not make specific limitation to the alcohol in the alcohol gel endothermic agent, the water-alcohol mixed gel or the mixed solution of liquid water and alcohol, and at least one of methanol, ethanol, propanol, ethylene glycol, glycerol and propylene glycol can be selected.

[0067] The utility model does not make specific limitation to the ratio of water and alcohol in the water-alcohol mixed gel or the mixed solution of liquid water and alcohol, and only needs to make the enthalpy value of the endothermic agent ≥1200J / g.

[0068] When the gel state endothermic agent or the liquid state endothermic agent is a mixture of multiple specific substances in the foregoing substances, the utility model does not make specific limitation to the ratio between each specific substance.

[0069] The thermal insulation assembly of the utility model can also include a packaging layer, and the packaging layer includes a packaging cavity. The thermal insulation assembly can be packaged in the packaging cavity, and the gel state endothermic layer or the liquid state endothermic layer in the thermal insulation layer 1 will not leak during use. Therefore, the thermal insulation assembly can be arranged between adjacent battery cells or batteries to prevent the chain thermal runaway reaction caused by the thermal runaway of a certain battery cell or battery.

[0070] Further, the encapsulation layer comprises one of PET film, PI film, aluminum plastic film, aluminum alloy foil, steel foil, aluminum strip and steel strip.

[0071] The utility model discloses a second aspect further provides a kind of safety battery, including safety battery and encapsulation structure, and safety battery includes cell base body and the first aspect's heat insulation component being adjacently arranged with cell base body;Safety battery is encapsulated in the encapsulation cavity of encapsulation structure.

[0072] Figure 4 It is an embodiment diagram of the safety battery of the utility model, Figure 4 In the embodiment, the heat insulation component 4 is located between the first cell base body 5 and the second cell base body 6.

[0073] It should be explained that when the safety battery is a liquid battery, the cell base body of the utility model includes a positive electrode, a negative electrode, and a separator and an electrolyte between the positive and negative electrodes; when the safety battery is a solid-state battery, the cell base body includes a positive electrode, a negative electrode, and a solid-state electrolyte between the positive and negative electrodes.

[0074] The battery at the present stage only includes a cell base body and an encapsulation structure, and when the cell base body experiences thermal runaway, the heat generated will quickly spread to the environment around the cell base body, which poses a great safety hazard. The utility model sets a heat insulation component between adjacent cell base bodies.

[0075] The heat insulation component not only can absorb and block the heat released by the cell base body in normal working state, but also can produce good heat absorption and heat insulation effect when the cell base body on one side of the heat insulation component experiences thermal runaway, thereby reducing the heat transferred to the cell base body on the other side of the heat insulation component and avoiding further expansion of the scale of thermal runaway.

[0076] The utility model discloses a third aspect further provides a kind of battery component, and battery component includes adjacent battery, and it includes the heat insulation component of the first aspect between adjacent battery.

[0077] By setting a heat insulation component between adjacent batteries, heat transfer between multiple batteries is reduced, the heat generated by thermal runaway is prevented from spreading to the surrounding environment, and the possibility of causing thermal runaway of adjacent batteries is reduced.

[0078] The utility model does not limit the number of cell base bodies in the battery, and can include only one cell base body or multiple cell base bodies.

[0079] Further, in one specific embodiment, the battery assembly of the present application comprises adjacent batteries, and further, the batteries can be the safety battery of the second aspect. At this time, the heat insulation assembly can not only block the heat transfer between the cell bodies, but also block the heat transfer between the batteries, playing a role of "double insurance". Even if a certain cell body has thermal runaway, and the excessive heat is not effectively blocked by the heat insulation assembly adjacent to the cell body, the overflowed heat can also be absorbed and blocked by the heat insulation assembly between the batteries, thereby greatly reducing the occurrence of safety accidents such as explosion and fire of the battery assembly.

[0080] The fourth aspect of the present application also provides an electronic device comprising the safety battery or the battery assembly.

[0081] The electronic device described above includes but is not limited to computers, mobile phones, electric vehicles, etc. Using the safety battery or the battery assembly provided with the heat insulation assembly described above can effectively avoid the explosion and combustion of adjacent cells or even battery assemblies due to thermal runaway of the cells or batteries in a high-temperature environment, and effectively improve the safety performance of the electronic device.

[0082] Embodiment 1

[0083] The heat insulation assembly of the present embodiment comprises glass fiber felt reinforced silica aerogel 1 and hydrogel filled in the through hole thereof, and is encapsulated in a PET film. The mass ratio of the glass fiber felt reinforced silica aerogel and the hydrogel is 0.5:1.

[0084] The glass fiber felt reinforced silica aerogel 1 has a thermal conductivity of 0.020 W / mK at 25℃ and a thermal conductivity of 0.050 W / mK at 300℃; and a contact angle of 20°.

[0085] The enthalpy value of the hydrogel is 1700 J / g, the freezing point temperature is -25℃, and the water content is 80%;

[0086] The enthalpy value of the heat insulation assembly in the present embodiment is 1090 J / g, the thermal conductivity before phase change is 0.5 W / mK, and the density is 860 Kg / m 3 .

[0087] The total thickness of the glass fiber felt reinforced silica aerogel 1 and the hydrogel in the heat insulation assembly is 2mm, the thickness of the glass fiber felt reinforced silica aerogel 1 is 2mm, and d1 / d=1 is satisfied.

[0088] Embodiment 2

[0089] The heat insulation assembly of the present embodiment comprises ceramic fiber reinforced alumina aerogel and water-alcohol mixed gel filled in the through hole thereof, and is encapsulated in a PI film. The mass ratio of the ceramic fiber reinforced alumina aerogel and the water-alcohol mixed gel is 0.7:1.

[0090] The ceramic fiber reinforced alumina aerogel has a thermal conductivity of 0.025 W / mK at 25℃ and 0.072 W / mK at 300℃, and a contact angle of 40°;

[0091] The water-alcohol mixed gel has an enthalpy of 1400 J / g, a freezing point of -40℃, a liquid content of 85%, and the alcohol is ethylene glycol, and the mass ratio of water to alcohol is 2:8.

[0092] The enthalpy of the thermal insulation assembly in this embodiment is 790 J / g, and the thermal conductivity before phase change is 0.3 W / mK, and the density is 740 Kg / m 3 .

[0093] The total thickness of the ceramic fiber reinforced alumina aerogel and the water-alcohol mixed gel in the thermal insulation assembly is 2mm, the thickness of the ceramic fiber reinforced alumina aerogel is 2mm, and d1 / d=1 is met.

[0094] Embodiment 3

[0095] The thermal insulation assembly of this embodiment includes a pre-oxidized fiber felt reinforced silica aerogel and liquid water filled in the through holes thereof, and is packaged in an aluminum plastic film. The mass ratio of the pre-oxidized fiber felt reinforced silica aerogel to the liquid water is 2:1.

[0096] The pre-oxidized fiber felt reinforced silica aerogel has a thermal conductivity of 0.021 W / mK at 25℃ and 0.058 W / mK at 300℃, and a contact angle of 80°;

[0097] The liquid water has an enthalpy of 2200 J / g, a freezing point of -20℃, and the freezing point of water is adjusted by adding calcium chloride;

[0098] The enthalpy of the thermal insulation assembly in this embodiment is 730 J / g, and the thermal conductivity before phase change is 0.18 W / mK, and the density is 530 Kg / m 3 .

[0099] The total thickness of the pre-oxidized fiber felt reinforced silica aerogel and the liquid water in the thermal insulation assembly is 3mm, the thickness of the pre-oxidized fiber felt reinforced silica aerogel is 3mm, and d1 / d=1 is met.

[0100] Embodiment 4

[0101] The thermal insulation assembly of this embodiment includes an aramid fiber felt reinforced silica aerogel and a liquid water-alcohol mixed solution filled in the through holes thereof, the alcohol is glycerol, the mass ratio of water to alcohol is 1:9, and is packaged in an aluminum alloy foil. The mass ratio of the aramid fiber felt reinforced silica aerogel to the liquid water-alcohol mixed solution is 1:1.

[0102] The thermal conductivity of the aramid fiber felt reinforced silica aerogel is 0.020 W / mK at 25℃ and 0.060 W / mK at 300℃, and the contact angle is 70°;

[0103] The enthalpy of the liquid water and alcohol mixed solution is 1500 J / g, and the freezing point temperature is -34℃;

[0104] The enthalpy of the thermal insulation assembly in the embodiment is 750 J / g, the thermal conductivity before phase change is 0.21 W / mK, and the density is 650 Kg / m 3 .

[0105] The total thickness of the aramid fiber felt reinforced silica aerogel and the liquid water and alcohol mixed solution in the thermal insulation assembly is 5 mm, the thickness of the aramid fiber felt reinforced silica aerogel is 5 mm, and d1 / d=1 is met.

[0106] Example 5

[0107] In the embodiment, the thermal insulation assembly further includes a hydrogel heat absorption layer in addition to the thermal insulation layer and the hydrogel heat absorption agent filled in the pore structure of the thermal insulation layer. The hydrogel heat absorption layer covers the upper and lower surfaces of the thermal insulation layer, and the hydrogel heat absorption layer is connected with the hydrogel heat absorption agent in the glass fiber felt reinforced silica aerogel and is encapsulated in a steel foil. The mass ratio of the glass fiber felt reinforced ferric sesquioxide aerogel and the hydrogel is 0.25:1.

[0108] The thermal conductivity of the glass fiber felt reinforced ferric sesquioxide aerogel is 0.018 W / mK at 25℃ and 0.054 W / mK at 300℃, and the contact angle is 60°;

[0109] The enthalpy of the hydrogel is 1700 J / g, the freezing point temperature is -25℃, and the liquid content is 80%;

[0110] The enthalpy of the thermal insulation assembly in the embodiment is 1360 J / g, the thermal conductivity before phase change is 0.48 W / mK, and the density is 880 Kg / m 3 .

[0111] The total thickness of the glass fiber felt reinforced ferric sesquioxide aerogel and the hydrogel in the thermal insulation assembly is 18 mm, the thickness of the glass fiber felt reinforced ferric sesquioxide aerogel is 9 mm, and d1 / d=0.5 is met.

[0112] Example 6

[0113] The difference between the embodiment and example 5 is that the ratio of the thickness d1 of the glass fiber felt reinforced silica aerogel to the total thickness d of the glass fiber felt reinforced silica aerogel and the hydrogel is d1 / d=1. The mass ratio of the thermal insulation layer and the heat absorption agent is 0.5.

[0114] Example 7

[0115] The difference between this example and Example 1 is that the mass ratio of the glass fiber mat reinforced silica aerogel and the hydrogel is 2.5:1.

[0116] Example 8

[0117] The difference between this example and Example 1 is that the glass fiber mat reinforced silica aerogel is replaced by a pre-oxidized fiber mat reinforced silica aerogel, and the thermal conductivity of the pre-oxidized fiber mat reinforced silica aerogel is 0.021 W / mK at 25℃ and 0.058 W / mK at 300℃; the contact angle is 120°.

[0118] Example 9

[0119] The difference between this example and Example 1 is that the endothermic agent hydrogel is replaced by liquid water, and the enthalpy of the liquid water is 2200 J / g, and the freezing point temperature is 0℃.

[0120] Example 10

[0121] The difference between this example and Example 5 is that d1 / d is adjusted to 0.4.

[0122] Comparative Example 1

[0123] The difference between this example and Example 1 is that the endothermic agent is sodium acetate trihydrate, and the enthalpy of sodium acetate trihydrate is 890 J / g.

[0124] The enthalpy of the thermal insulation assembly in this example is 590 J / g, the thermal conductivity before phase change is 0.2 W / mK, and the density is 1090 Kg / m 3 .

[0125] The total thickness of the glass fiber mat reinforced silica aerogel and sodium acetate trihydrate in the thermal insulation assembly is 2mm, the thickness of the glass fiber mat reinforced silica aerogel is 2mm, and d1 / d=1 is met.

[0126] Comparative Example 2

[0127] The difference between this example and Example 1 is that the thermal insulation layer is selected to be a glass fiber mat.

[0128] The thermal conductivity of the glass fiber mat is 0.035 W / mK at 25℃ and 0.18 W / mK at 300℃; the contact angle is 60°;

[0129] The enthalpy of the thermal insulation assembly in this embodiment is 1090 J / g, the thermal conductivity before phase change is 0.52 W / mK, and the density is 760 Kg / m 3 .

[0130] The total thickness of the glass fiber felt and the hydrogel in the thermal insulation assembly is 2 mm, the thickness of the glass fiber felt is 2 mm, and d1 / d = 1 is met.

[0131] Comparative Example 3

[0132] The difference between this embodiment and Example 1 is that the thermal insulation layer is selected as a glass fiber felt, and the heat absorber is selected as sodium acetate trihydrate.

[0133] The thermal conductivity of the glass fiber felt at 25°C is 0.035 W / mK, and the thermal conductivity at 300°C is 0.18 W / mK; the contact angle is 60°;

[0134] The enthalpy of sodium acetate trihydrate is 890 J / g;

[0135] The enthalpy of the thermal insulation assembly in this embodiment is 590 J / g, the thermal conductivity before phase change is 0.28 W / mK, and the density is 1060 Kg / m 3 .

[0136] The total thickness of the glass fiber felt and the hydrogel in the thermal insulation assembly is 2 mm, the thickness of the glass fiber felt is 2 mm, and d1 / d = 1 is met.

[0137] Test Example

[0138] The battery module as shown in Figure 4 is formed by the battery cell and the thermal insulation assembly packaged in Examples 1-10 and Comparative Examples 1-3. The first battery cell body 5 and the second battery cell body 6 are 100% SOC, the battery cell temperature is 45°C, and the new thermal insulation assembly 4 is placed between the first battery cell body 5 and the second battery cell body 6. The above battery module is subjected to safety test, specifically, the first battery cell body 5 is triggered to lose control by heating or needle pricking, whether the second battery cell body 6 will diffuse (i.e. whether thermal runaway will occur) is observed, and the diffusion time of the second battery cell body 6 (i.e. the time from the thermal runaway of the first battery cell body 5 to the thermal runaway of the second battery cell body 6) and the highest temperature of the second battery cell body during the whole process are recorded. The test cutoff condition is that the battery cell temperature is reduced to 60°C or lower.

[0139] Table 1 is the safety test results of Examples 1-10 and Comparative Examples 1-3.

[0140] Table 1

[0141]

[0142] As can be seen from Table 1, compared with Comparative Examples 1-3, the battery module in each of Examples 1-10 has higher safety, wherein in the battery module in Example 5, the highest temperature of the second cell substrate is only 125 DEG C, and no diffusion occurs; while in the battery module in Comparative Example 3, the second cell substrate diffuses, and the diffusion time is 12 min, and correspondingly, the highest temperature of the second cell substrate is 522 DEG C. It can be known that the heat insulation layer in the present scheme can effectively control the spread of the thermal runaway risk, and avoid causing the adjacent cell substrate to overheat and fail under the high temperature environment.

[0143] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A thermally insulating assembly, characterized in that, The thermal insulation layer comprises a pore structure, and the heat-absorbing agent is filled in at least part of the pore structure of the thermal insulation layer; The thermal insulation layer is a fiber felt reinforced aerogel, and the thermal conductivity of the fiber felt reinforced aerogel is ≤0.025 W / mK at 25℃ and ≤0.075 W / mK at 300℃. The heat-absorbing agent is a gel state heat-absorbing agent or a liquid state heat-absorbing agent, and the heat-absorbing agent absorbs heat and is converted into a gaseous state, and the enthalpy of the heat-absorbing agent is ≥1200 J / g.

2. The insulating assembly of claim 1, wherein, The enthalpy of the thermal insulation assembly is ≥400 J / g; and / or, The thermal conductivity of the thermal insulation assembly before phase change is <0.8 W / mK.

3. The insulating assembly of claim 1, wherein, The density of the thermal insulation assembly is 200-1000 Kg / m 3 .

4. The thermally insulating assembly of claim 1, wherein, The pore structure is a through hole, and the heat-absorbing agent is completely filled in the through hole.

5. The thermally insulating assembly of claim 1, wherein, Further comprising a heat-absorbing layer covering at least one surface of the thermal insulation layer, and the heat-absorbing layer is connected with the heat-absorbing agent in the pore structure; the heat-absorbing layer comprises the heat-absorbing agent.

6. The insulating assembly of claim 5, wherein, The total thickness of the thermal insulation assembly is d, the thickness of the thermal insulation layer is d1, and 0.5≤d1 / d≤1 is satisfied.

7. A thermally insulating assembly according to claim 1 or 5 or 6, characterized in that The mass ratio of the thermal insulation layer and the heat-absorbing agent is (0.1-2):

1.

8. A thermal insulation assembly according to any of claims 1-6, characterized in that The contact angle of the thermal insulation layer with water is ≤90°.

9. The thermally insulating assembly of claim 1, wherein, The thermal insulation layer is at least one of a glass fiber felt reinforced aerogel, a ceramic fiber reinforced aerogel, a pre-oxidized fiber felt reinforced aerogel, and an aramid fiber felt reinforced aerogel.

10. The thermally insulating assembly of claim 1 or 8, wherein, The aerogel component of the thermal insulation layer is at least one of a silica aerogel and / or an alumina aerogel.

11. A thermally insulating assembly according to any one of claims 1-5, characterized in that The freezing point temperature of the heat-absorbing agent is ≤-20℃.

12. The insulating assembly according to any one of claims 1-5, characterized in that The gel state heat-absorbing agent comprises at least one of a hydrogel heat-absorbing agent, an alcohol gel heat-absorbing agent, and a water-alcohol mixed gel; Or, the liquid state heat-absorbing agent comprises a liquid water and / or a mixed solution of liquid water and alcohol.

13. The insulating assembly of claim 12, wherein, The liquid content in the gel state heat-absorbing agent is ≥50%.

14. The thermally insulating assembly of claim 1, wherein, The thermal insulation assembly further comprises an encapsulation layer, and the encapsulation layer comprises an encapsulation cavity, and the thermal insulation assembly is encapsulated in the encapsulation cavity.

15. The insulating assembly of claim 14, wherein, The material of the encapsulation layer comprises one of a PET film, a PI film, an aluminum plastic film, an aluminum alloy foil, a steel foil, an aluminum strip, and a steel strip.

16. A safety battery, characterized by The battery assembly comprises adjacent batteries, and the thermal insulation assembly according to any one of claims 1-15 is arranged between the adjacent batteries.

17. A battery assembly characterized by, The battery assembly comprises adjacent batteries, and the thermal insulation assembly according to any one of claims 1-15 is arranged between the adjacent batteries.

18. The battery assembly of claim 17, wherein, The battery assembly comprises adjacent batteries, and the thermal insulation assembly according to any one of claims 1-15 is arranged between the adjacent batteries.

19. An electronic device, comprising: The battery assembly comprises adjacent batteries, and the thermal insulation assembly according to any one of claims 1-15 is arranged between the adjacent batteries.

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